# Patent

## Title
Layered chip package with wiring on the side surfaces

## Abstract

A layered chip package has a main body including pairs of layer portions, and wiring disposed on a side surface of the main body. Each layer portion includes a semiconductor chip. The pairs of layer portions include specific pairs of layer portions. Each of the specific pairs of layer portions includes a first-type layer portion and a second-type layer portion. The first-type layer portion includes electrodes each connected to the semiconductor chip and each having an end face located at the side surface of the main body on which the wiring is disposed, whereas the second-type layer portion does not include such electrodes. The specific pairs of layer portions are provided in an even number.

## Background
This is a Division of application Ser. No. 12/320,884 filed Feb. 6, 2009. The disclosure of the prior application is hereby incorporated by reference herein in its entirety.


BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a layered chip package including a plurality of chips stacked, and to a method of manufacturing the same.
2. Description of the Related Art
In recent years, a reduction in weight and an improvement in performance have been demanded of mobile devices typified by cellular phones and notebook personal computers. Accordingly, there has been a demand for higher integration of electronic components for use in mobile devices. Higher integration of electronic components has been demanded also for achieving an increase in capacity of semiconductor memory.
As an example of highly integrated electronic components, a system-in-package (hereinafter referred to as SiP), especially an SiP utilizing a three-dimensional packaging technology for stacking a plurality of chips, has attracting attention in recent years. In the present application, a package including a plurality of chips stacked is called a layered chip package. Since the layered chip package allows a reduction in wiring length, it provides the advantage of allowing a higher operation speed for a circuit and a reduction in stray capacitance of wiring, as well as the advantage of allowing higher integration.
Major examples of three-dimensional packaging technology for fabricating a layered chip package include a wire bonding method and a through electrode method. According to the wire bonding method, a plurality of chips are stacked on a substrate and a plurality of electrodes formed on each chip are connected, by wire bonding, to external connecting terminals formed on the substrate. According to the through electrode method, a plurality of through electrodes are formed in each of chips to be stacked and inter-chip wiring is performed through the use of the through electrodes.
The wire bonding method has a problem that it is difficult to reduce the distance between the electrodes so as to avoid contact between wires, and a problem that high resistances of the wires hamper a high-speed operation of a circuit.
The through electrode method is free from the above-mentioned problems of the wire bonding method. Unfortunately, however, the through electrode method requires a large number of steps for forming the through electrodes in chips, and consequently increases the cost for the layered chip package. According to the through electrode method, forming the through electrodes in chips requires a series of steps as follows: forming a plurality of holes for the plurality of through electrodes in a wafer that will be cut later into a plurality of chips; forming an insulating layer and a seed layer in the plurality of holes and on the top surface of the wafer; forming a plurality of through electrodes by filling the plurality of holes with metal such as Cu by plating; and removing unwanted portions of the seed layer.
According to the through electrode method, the through electrodes are formed by filling metal into holes having relatively high aspect ratios. Consequently, voids or keyholes are prone to occur in the through electrodes due to poor filling of the holes with metal, so that the reliability of wiring formed by the through electrodes tends to be reduced.
According to the through electrode method, an upper chip and a lower chip are physically joined to each other by connecting the through electrodes of the upper and lower chips by means of, for example, soldering. The through electrode method therefore requires that the upper and lower chips be accurately aligned and then joined to each other at high temperatures. When the upper and lower chips are joined to each other at high temperatures, however, misalignment between the upper and lower chips can occur due to expansion and contraction of the chips, which often results in electrical connection failure between the upper and lower chips.
U.S. Pat. No. 5,953,588 discloses a method of manufacturing a layered chip package as described below. In this method, a plurality of chips cut out from a processed wafer are embedded into an embedding resin and then a plurality of leads are formed to be connected to each chip, whereby a structure called a neo-wafer is fabricated. Next, the neo-wafer is diced to form a plurality of structures each called a neo-chip. Each neo-chip includes: one or more chips; resin surrounding the chip(s); and a plurality of leads. The plurality of leads connected to each chip each have an end face exposed at a side surface of the neo-chip. Next, a plurality of kinds of neo-chips are laminated into a stack. In the stack, the respective end faces of the plurality of leads connected to the chips of each layer are exposed at the same side surface of the stack.
Keith D. Gann, “Neo-Stacking Technology”, HDI Magazine, December 1999, discloses fabricating a stack by the same method as U.S. Pat. No. 5,953,588, and forming wiring on two side surfaces of the stack.
The manufacturing method disclosed in U.S. Pat. No. 5,953,588 involves a number of process steps and this raises the cost for the layered chip package. According to this method, after the plurality of chips cut out from a processed wafer are embedded into the embedding resin, the plurality of leads are formed to be connected to each chip to thereby fabricate the neo-wafer, as described above. Accurate alignment of the plurality of chips is therefore required when fabricating the neo-wafer. This is also a factor that raises the cost for the layered chip package.
U.S. Pat. No. 7,127,807 B2 discloses a multilayer module formed by stacking a plurality of active layers each including a flexible polymer substrate with at least one electronic element and a plurality of electrically-conductive traces formed within the substrate. According to this multilayer module, however, it is impossible to increase the proportion of the area occupied by the electronic element in each active layer, and consequently it is difficult to achieve higher integration.
For a wafer to be cut into a plurality of chips, the yield of the chips, that is, the rate of non-defective chips with respect to all chips obtained from the wafer, is 90% to 99% in many cases. Since a layered chip package includes a plurality of chips, the rate of layered chip packages in which all of the plurality of chips are non-defective is lower than the yield of the chips. The larger the number of chips included in each layered chip package, the lower the rate of layered chip packages in which all of the chips are non-defective.
A case will now be considered where a memory device such as a flash memory is formed using a layered chip package. In general, a redundancy technique of replacing a defective column of memory cells with a redundant column of memory cells is employed in a memory device such as a flash memory so that the memory device can normally function even when some memory cells are defective. In the case where a memory device is formed using a layered chip package, the redundancy technique is also employable to make it possible that, even if some of memory cells included in any chip are defective, the memory device can normally function while using the chip including the defective memory cells. However, if, for example, a chip that includes a control circuit and a plurality of memory cells has become defective due to a wiring failure in the control circuit and cannot function normally even by employing the redundancy technique, this defective chip is unusable. In this case, replacing the defective chip with a non-defective one raises the cost for the layered chip package.
US 2007/0165461 A1 discloses a technique of identifying one or more defective flash memory dies in a flash memory device having a plurality of flash memory dies, and disabling memory access operations to each identified die.
The technique disclosed in US 2007/0165461 A1 is applicable to the case where a memory device is formed using a layered chip package, so that one or more defective chips included in the layered chip package can be identified and disabled.
However, disabling a defective chip in a layered chip package involves a problem as described below. A layered chip package has wiring for connecting each chip to a plurality of terminals of the layered chip package. Even if a defective chip is disabled, there exists wiring that connects the defective chip to a plurality of terminals of the layered chip package. The wiring connecting the defective chip to the plurality of terminals of the layered chip package generates a capacitance or inductance that is unwanted for a device implemented by the layered chip package, such as a memory device, and/or generates a stray capacitance between itself and other wiring connected to non-defective chips. This is a hindrance to increasing the operation speed of the device such as the memory device.
In addition, if a layered chip package including a predetermined number of chips is able to implement a memory device having a desired memory capacity when all the chips included in the layered chip package are non-defective, it is impossible to implement the memory device having the desired memory capacity by simply disabling a defective chip included in the layered chip package.
OBJECT AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a layered chip package and its manufacturing method that make it possible to implement, at low cost, a layered chip package including a plurality of chips stacked, the layered chip package being capable of disabling the use of a malfunctioning chip while reducing problems attributable to wiring connected to the malfunctioning chip, and also capable of performing equally well irrespective of whether a malfunctioning chip is included or not.
A layered chip package manufactured by a method of manufacturing a layered chip package according to the present invention includes: a main body having a top surface, a bottom surface and four side surfaces; and wiring disposed on at least one of the side surfaces of the main body. The main body includes a plurality of pairs of layer portions stacked, each of the plurality of pairs consisting of two layer portions stacked. The plurality of pairs of layer portions include at least one specific pair of layer portions, the specific pair of layer portions consisting of a first-type layer portion and a second-type layer portion. Each of the first-type layer portion and the second-type layer portion includes a semiconductor chip. The semiconductor chip included in the first-type layer portion is a normally functioning one whereas the semiconductor chip included in the second-type layer portion is a malfunctioning one. The first-type layer portion further includes a plurality of electrodes, each of the plurality of electrodes being connected to the semiconductor chip and having an end face located at the at least one of the side surfaces of the main body on which the wiring is disposed, whereas the second-type layer portion does not include any electrode connected to the semiconductor chip and having an end face located at the at least one of the side surfaces of the main body on which the wiring is disposed. The wiring is connected to the end face of each of the plurality of electrodes.
The method of manufacturing a layered chip package according to the present invention includes the steps of: fabricating a layered substructure by stacking two substructures each of which includes a plurality of preliminary layer portions aligned, each of the preliminary layer portions being intended to become any one of the layer portions included in the main body, the substructures being intended to be cut later at a boundary between every adjacent two of the preliminary layer portions; fabricating a pre-main-body stack by using the layered substructure, the pre-main-body stack being a stack of a predetermined two or greater number of pairs of layer portions including the at least one specific pair of layer portions; fabricating the main body by stacking at least one additional first-type layer portion together with the pre-main-body stack, the number of the at least one additional first-type layer portion being equal to the number of the at least one specific pair of layer portions included in the pre-main-body stack; and completing the layered chip package by forming the wiring on the main body.
The step of fabricating the layered substructure includes, as a series steps for fabricating each substructure, the step of fabricating a pre-substructure wafer including a plurality of pre-semiconductor-chip portions aligned; the step of distinguishing between a normally functioning pre-semiconductor-chip portion and a malfunctioning pre-semiconductor-chip portion among the plurality of pre-semiconductor-chip portions included in the pre-substructure wafer; and the step of forming the plurality of electrodes so as to be connected to the normally functioning pre-semiconductor-chip portion, without forming any electrode connected to the malfunctioning pre-semiconductor-chip portion and having an end face located at the at least one of the side surfaces of the main body on which the wiring is disposed.
In the method of manufacturing a layered chip package according to the present invention, the predetermined two or greater number may be four.
In the method of manufacturing a layered chip package according to the present invention, the semiconductor chip may have four side surfaces, and each of the plurality of layer portions may further include an insulating portion covering at least one of the four side surfaces of the semiconductor chip. In this case, the insulating portion may have at least one end face located at the at least one of the side surfaces of the main body on which the wiring is disposed, and the end face of each of the plurality of electrodes may be surrounded by the insulating portion.
In the method of manufacturing a layered chip package according to the present invention, in the step of fabricating the main body, the main body may be fabricated by stacking at least one additional specific pair of layer portions together with the pre-main-body stack, the number of the at least one additional specific pair of layer portions being equal to the number of the at least one specific pair of layer portions included in the pre-main-body stack. In this case, in the step of fabricating the main body, one of the at least one additional specific pair of layer portions stacked with the pre-main-body stack may be disposed closest to the top surface or the bottom surface of the main body among the plurality of pairs of layer portions included in the main body. The layered chip package may further include a plurality of terminals disposed on one of the top surface and the bottom surface of the main body, and the wiring may be connected to the plurality of terminals. The method of manufacturing a layered chip package may further include the step of forming the plurality of terminals performed before the step of completing the layered chip package. In this case, in the step of fabricating the main body, one of the at least one additional specific pair of layer portions stacked with the pre-main-body stack may be disposed farthest from the surface of the main body on which the plurality of terminals are disposed, among the plurality of pairs of layer portions included in the main body.
In the method of manufacturing a layered chip package according to the present invention, in the step of fabricating the main body, one of the at least one additional first-type layer portion stacked with the pre-main-body stack may be disposed closest to the top surface or the bottom surface of the main body among the plurality of pairs of layer portions included in the main body.
The layered chip package may further include a plurality of terminals disposed on one of the top surface and the bottom surface of the main body, and the wiring may be connected to the plurality of terminals. The method of manufacturing the layered chip package may further include the step of forming the plurality of terminals performed before the step of completing the layered chip package. In this case, in the step of fabricating the main body, one of the at least one additional first-type layer portion stacked with the pre-main-body stack may be disposed farthest from the surface of the main body on which the plurality of terminals are disposed, among the plurality of pairs of layer portions included in the main body. Alternatively, the step of fabricating the main body and the step of forming the plurality of terminals may be performed simultaneously by stacking the at least one additional first-type layer portion with the plurality of terminals integrated therewith, together with the pre-main-body stack.
In the method of manufacturing a layered chip package according to the present invention, the step of fabricating the pre-main-body stack may include the steps of: fabricating at least one bar by cutting the layered substructure, the at least one bar including a plurality of portions each of which is to become any one of the plurality of pairs of layer portions included in the main body, the plurality of portions being aligned in one direction orthogonal to a stacking direction of the layer portions; cutting the at least one bar so as to form a plurality of pairs of layer portions, each of the plurality of pairs being intended to become any one of the plurality of pairs of layer portions included in the main body; and completing the pre-main-body stack by stacking the predetermined two or greater number of pairs of layer portions.
In the method of manufacturing a layered chip package according to the present invention, the step of fabricating the pre-main-body stack may include the steps of: fabricating a plurality of bars by cutting the layered substructure, each of the plurality of bars including a plurality of portions each of which is to become any one of the plurality of pairs of layer portions included in the main body, the plurality of portions being aligned in one direction orthogonal to the stacking direction of the layer portions; fabricating a bar stack by stacking two or more of the bars, the number of the bars to be stacked being equal to the predetermined two or greater number, the bar stack including a plurality of portions each of which is to become the pre-main-body stack, the plurality of portions being aligned in one direction orthogonal to the stacking direction of the layer portions; and completing the pre-main-body stack by cutting the bar stack.
In the method of manufacturing a layered chip package according to the present invention, the step of fabricating the pre-main-body stack may include the steps of: fabricating a stack aggregate by stacking a number of layered substructures, the number of the layered substructures to be stacked being equal to the predetermined two or greater number, the stack aggregate including a plurality of portions each of which is to become the pre-main body stack, the plurality of portions being aligned in one direction orthogonal to the stacking direction of the layer portions; and completing the pre-main-body stack by cutting the stack aggregate.
In the method of manufacturing a layered chip package according to the present invention, the step of forming the plurality of electrodes may include the steps of: forming a photoresist layer for use for forming the plurality of electrodes, the photoresist layer including a plurality of portions that respectively correspond to all of the pre-semiconductor-chip portions; forming a frame by patterning the photoresist layer by photolithography, the frame having a plurality of grooves to later accommodate the plurality of electrodes; and forming the plurality of electrodes in the grooves of the frame. In this case, in the step of forming the plurality of electrodes in the grooves of the frame, the plurality of electrodes may be formed by plating.
The step of forming the frame may include an exposure step of exposing the photoresist layer such that a latent image corresponding to the plurality of electrodes is formed on a portion of the photoresist layer corresponding to the normally functioning pre-semiconductor-chip portion, whereas any latent image corresponding to an electrode connected to the malfunctioning pre-semiconductor-chip portion and having an end face located at the at least one of the side surfaces of the main body on which the wiring is disposed is not formed on a portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion; and a step of developing the photoresist layer performed after the exposure step.
The photoresist layer may be negative-working. In this case, the step of forming the frame may include: an exposure step in which a portion of the photoresist layer corresponding to the normally functioning pre-semiconductor-chip portion is exposed in a pattern corresponding to the plurality of electrodes whereas a portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion is subjected to an overall exposure; and a step of developing the photoresist layer performed after the exposure step.
The photoresist layer may be positive-working. In this case, the step of forming the frame may include: an exposure step in which a portion of the photoresist layer corresponding to the normally functioning pre-semiconductor-chip portion is exposed in a pattern corresponding to the plurality of electrodes whereas a portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion is not subjected to any exposure; and a step of developing the photoresist layer performed after the exposure step.
In the case where the photoresist layer is negative-working, the step of forming the frame may include: a first exposure step of exposing all of the plurality of portions of the photoresist layer in a pattern corresponding to the plurality of electrodes; a second exposure step of subjecting only a portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion to an overall exposure, the second exposure step being performed before or after the first exposure step; and a step of developing the photoresist layer performed after the first and second exposure steps.
A first layered chip package according to the present invention includes: a main body having a top surface, a bottom surface and four side surfaces; and wiring disposed on at least one of the side surfaces of the main body. The main body includes a plurality of pairs of layer portions stacked, each of the plurality of pairs consisting of two layer portions stacked. The plurality of pairs of layer portions include a plurality of specific pairs of layer portions, each of the plurality of specific pairs consisting of a first-type layer portion and a second-type layer portion. The number of the plurality of specific pairs is an even number. Each of the first-type layer portion and the second-type layer portion includes a semiconductor chip. The first-type layer portion further includes a plurality of electrodes, each of the plurality of electrodes being connected to the semiconductor chip and having an end face located at the at least one of the side surfaces of the main body on which the wiring is disposed, whereas the second-type layer portion does not include any electrode connected to the semiconductor chip and having an end face located at the at least one of the side surfaces of the main body on which the wiring is disposed. The wiring is connected to the end face of each of the plurality of electrodes.
In the first layered chip package according to the present invention, the plurality of pairs of layer portions may further include at least one pair of two first-type layer portions.
In the first layered chip package according to the present invention, the number of the first-type layer portions included in the main body may be eight.
In the first layered chip package according to the present invention, the semiconductor chip included in the first-type layer portion may be a normally functioning one whereas the semiconductor chip included in the second-type layer portion may be a malfunctioning one.
In the first layered chip package according to the present invention, the semiconductor chip may have four side surfaces, and each of the first-type layer portion and the second-type layer portion may further include an insulating portion covering at least one of the four side surfaces of the semiconductor chip. In this case, the insulating portion may have at least one end face located at the at least one of the side surfaces of the main body on which the wiring is disposed, and the end face of each of the plurality of electrodes may be surrounded by the insulating portion.
In the first layered chip package according to the present invention, one of the plurality of specific pairs of layer portions may be disposed closest to the top surface or the bottom surface of the main body among the plurality of pairs of layer portions included in the main body.
The first layered chip package according to the present invention may further include a plurality of terminals disposed on one of the top surface and the bottom surface of the main body, and the wiring may be connected to the plurality of terminals. In this case, one of the plurality of specific pairs of layer portions may be disposed farthest from the surface of the main body on which the plurality of terminals are disposed, among the plurality of pairs of layer portions included in the main body.
A second layered chip package according to the present invention includes: a main body having a top surface, a bottom surface and four side surfaces; and wiring disposed on at least one of the side surfaces of the main body. The main body includes at least nine layer portions stacked, the at least nine layer portions consisting of eight first-type layer portions and at least one second-type layer portion. The at least nine layer portions include at least four pairs of layer portions, each of the at least four pairs consisting of two layer portions stacked. The at least four pairs of layer portions include at least one specific pair of layer portions, the specific pair of layer portions consisting of one each of the first-type and second-type layer portions. Each of the first-type and second-type layer portions includes a semiconductor chip. Each of the first-type layer portions further includes a plurality of electrodes, each of the plurality of electrodes being connected to the semiconductor chip and having an end face located at the at least one of the side surfaces of the main body on which the wiring is disposed, whereas the at least one second-type layer portion does not include any electrode connected to the semiconductor chip and having an end face located at the at least one of the side surfaces of the main body on which the wiring is disposed. The wiring is connected to the end face of each of the plurality of electrodes.
In the second layered chip package according to the present invention, the semiconductor chip included in each of the first-type layer portions may be a normally functioning one whereas the semiconductor chip included in each of the at least one second-type layer portion may be a malfunctioning one.
In the second layered chip package according to the present invention, the semiconductor chip may have four side surfaces, and each of the first-type and second-type layer portions may further include an insulating portion covering at least one of the four side surfaces of the semiconductor chip. In this case, the insulating portion may have at least one end face located at the at least one of the side surfaces of the main body on which the wiring is disposed, and the end face of each of the plurality of electrodes may be surrounded by the insulating portion.
In the second layered chip package according to the present invention, the at least nine layer portions may further include an additional first-type layer portion disposed closest to the top surface or the bottom surface of the main body among the at least nine layer portions.
The second layered chip package according to the present invention may further include a plurality of terminals disposed on one of the top surface and the bottom surface of the main body, and the wiring may be connected to the plurality of terminals. In this case, the at least nine layer portions may further include an additional first-type layer portion disposed farthest from or closest to the surface of the main body on which the plurality of terminals are disposed, among the at least nine layer portions.
According to the method of manufacturing a layered chip package of the present invention, or the first or second layered chip package of the present invention, it is possible to disable the use of a malfunctioning chip while reducing problems attributable to wiring connected to the malfunctioning chip.
According to the method of manufacturing a layered chip package of the present invention, the layered substructure is used to fabricate the pre-main-body stack which is a stack of a predetermined two or greater number of pairs of layer portions including at least one specific pair of layer portions, and the main body is fabricated by stacking at least one additional first-type layer portion together with the pre-main-body stack, the number of the at least one additional first-type layer portion being equal to the number of the at least one specific pair of layer portions included in the pre-main-body stack. The present invention thus makes it possible to implement, at low cost, a layered chip package that performs equally well irrespective of whether a malfunctioning chip is included or not.
In the first layered chip package according to the present invention, the number of the specific pairs of layer portions is an even number. When a stack of a predetermined number of pairs of layer portions includes at least one specific pair of layer portions, the main body of this layered chip package is formed by stacking at least one additional specific pair of layer portions together with the foregoing stack, the number of the at least one additional specific pair of layer portions being equal to the number of the at least one specific pair of layer portions included in the stack. The present invention thus makes it possible to implement, at low cost, a layered chip package that performs equally well irrespective of whether a malfunctioning chip (the chip in the second-type layer portion) is included or not.
In the second layered chip package according to the present invention, the main body includes at least nine layer portions stacked, the at least nine layer portions consisting of eight first-type layer portions and at least one second-type layer portion. The at least nine layer portions include at least four pairs of layer portions, and the at least four pairs of layer portions include at least one specific pair of layer portions. When a stack of four pairs of layer portions includes at least one specific pair of layer portions, the main body is formed by stacking at least one additional first-type layer portion together with the foregoing stack, the number of the at least one additional first-type layer portion being equal to the number of the at least one specific pair of layer portions included in the stack. The present invention thus makes it possible to implement, at low cost, a layered chip package that performs equally well irrespective of whether a malfunctioning chip (the chip in the second-type layer portion) is included or not.
Other and further objects, features and advantages of the present invention will appear more fully from the following description.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a layered chip package according to a first embodiment of the invention drawn such that respective end faces of a plurality of first electrodes are visible.
FIG. 2 is a perspective view of the layered chip package according to the first embodiment of the invention.
FIG. 3 is an exploded perspective view of a pair of layer portions included in the layered chip package of FIG. 1.
FIG. 4 is a cross-sectional view of a portion of a pre-substructure wafer fabricated in a step of a method of manufacturing the layered chip package according to the first embodiment of the invention.
FIG. 5 is a cross-sectional view of a portion of a pre-polishing substructure main body fabricated in a step that follows a distinction step performed on the pre-substructure wafer of FIG. 4.
FIG. 6 is a cross-sectional view of a portion of a structure fabricated in a step that follows the step of FIG. 5.
FIG. 7 is a cross-sectional view of a portion of a structure fabricated in a step that follows the step of FIG. 6.
FIG. 8 is a cross-sectional view of a portion of a pre-polishing substructure fabricated in a step that follows the step of FIG. 7.
FIG. 9 is a perspective view of the pre-substructure wafer fabricated in the step of FIG. 4.
FIG. 10 is a cross-sectional view illustrating an example of the internal structure of a pre-semiconductor-chip portion of the pre-substructure wafer of FIG. 9.
FIG. 11 is a perspective view of a portion of the pre-polishing substructure main body fabricated in the step of FIG. 5.
FIG. 12 is a perspective view of a portion of the pre-polishing substructure fabricated in the step of FIG. 8.
FIG. 13 is an illustrative view showing the step of distinguishing between a normally functioning pre-semiconductor-chip portion and a malfunctioning pre-semiconductor-chip portion in the method of manufacturing the layered chip package according to the first embodiment of the invention.
FIG. 14 is an illustrative view showing an example of the configuration of an exposure apparatus for use in the method of manufacturing the layered chip package according to the first embodiment of the invention.
FIG. 15 is a flow chart showing an exposure step for forming a plurality of electrodes in the method of manufacturing the layered chip package according to the first embodiment of the invention.
FIG. 16 is an illustrative view showing the exposure step for forming the plurality of electrodes in the method of manufacturing the layered chip package according to the first embodiment of the invention.
FIG. 17 is an illustrative view showing a development step that follows the exposure step of FIG. 16.
FIG. 18 is an illustrative view showing a plating step that follows the development step of FIG. 17.
FIG. 19 is a cross-sectional view of a portion of a stack fabricated in a step that follows the step of FIG. 8.
FIG. 20 is a cross-sectional view of a portion of a stack fabricated in a step that follows the step of FIG. 19.
FIG. 21 is a perspective view of a portion of a substructure fabricated in the step of FIG. 20.
FIG. 22 is a plan view showing an example of layouts of a plurality of terminals and a plurality of electrodes of a first substructure shown in FIG. 20.
FIG. 23 is a plan view showing an example of layouts of a plurality of terminals and a plurality of electrodes of a second substructure shown in FIG. 20.
FIG. 24 is an illustrative view showing a first example of the stop of fabricating a pre-main-body stack in the method of manufacturing the layered chip package according to the first embodiment of the invention.
FIG. 25 is an illustrative view showing a second example of the step of fabricating the pre-main-body stack in the method of manufacturing the layered chip package according to the first embodiment of the invention.
FIG. 26 is an illustrative view showing a third example of the step of fabricating the pre-main-body stack in the method of manufacturing the layered chip package according to the first embodiment of the invention.
FIG. 27 is a perspective view of a terminal wafer for use in the method of manufacturing the layered chip package according to the first embodiment of the invention.
FIG. 28 is a perspective view showing a pre-main-body stack that does not include a specific pair of layer portions.
FIG. 29 is an illustrative view showing the step of fabricating a main body in the method of manufacturing the layered chip package according to the first embodiment of the invention.
FIG. 30 is a perspective view showing a side surface of a layer portion included in the main body.
FIG. 31 is a perspective view showing a state in which a plurality of main bodies are aligned.
FIG. 32 is a perspective view showing a layered chip package that does not include a specific pair of layer portions.
FIG. 33 is a perspective view showing an example of use of the layered chip package according to the first embodiment of the invention.
FIG. 34 is a perspective view showing another example of use of the layered chip package according to the first embodiment of the invention.
FIG. 35 is a perspective view showing still another example of use of the layered chip package according to the first embodiment of the invention.
FIG. 36 is a perspective view showing a modification example of the layered chip package according to the first embodiment of the invention.
FIG. 37 is a perspective view of a layered chip package according to a second embodiment of the invention drawn such that respective end faces of a plurality of first electrodes are visible.
FIG. 38 is an illustrative view showing the step of fabricating a main body in a method of manufacturing the layered chip package according to the second embodiment of the invention.
FIG. 39 is a cross-sectional view showing a portion of a pre-polishing substructure for an additional layer portion for use in the method of manufacturing the layered chip package according to the second embodiment of the invention.
FIG. 40 is a cross-sectional view showing a portion of a substructure for the additional layer portion for use in the method of manufacturing the layered chip package according to the second embodiment of the invention.
FIG. 41 is a perspective view of a layered chip package according to a third embodiment of the invention drawn such that respective end faces of a plurality of first electrodes are visible.
FIG. 42 is an illustrative view showing the step of fabricating a main body in a method of manufacturing the layered chip package according to the third embodiment of the invention.
FIG. 43 is a perspective view showing a stack of a substructure and a terminal wafer for use in the method of manufacturing the layered chip package according to the third embodiment of the invention.
FIG. 44 is a flow chart showing an exposure step for forming a plurality of electrodes in a method of manufacturing a layered chip package according to a fourth embodiment of the invention.
FIG. 45 is an illustrative view showing the exposure step for forming the plurality of electrodes in the method of manufacturing the layered chip package according to the fourth embodiment of the invention.
FIG. 46 is an illustrative view showing a first exposure step for forming a plurality of electrodes in a method of manufacturing a layered chip package according to a fifth embodiment of the invention.
FIG. 47 is an illustrative view showing a second exposure step for forming the plurality of electrodes in the method of manufacturing the layered chip package according to the fifth embodiment of the invention.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
Embodiments of the present invention will now be described in detail with reference to the drawings. Reference is first made to FIG. 1 and FIG. 2 to describe the configuration of a layered chip package according to a first embodiment of the invention. Each of FIG. 1 and FIG. 2 is a perspective view of the layered chip package according to the present embodiment. FIG. 1 is drawn such that respective end faces of a plurality of first electrodes described later are visible. As shown in FIG. 1 and FIG. 2, the layered chip package 1 according to the present embodiment includes a main body 2 in the shape of a rectangular solid. The main body 2 has a top surface 2a, a bottom surface 2b, a first side surface 2c and a second side surface 2d facing toward opposite directions, and a third side surface 2e and a fourth side surface 2f facing toward opposite directions.
The layered chip package 1 further includes wiring disposed on at least one of the side surfaces of the main body 2. In the example shown in FIG. 1 and FIG. 2, the layered chip package 1 includes first wiring 3A disposed on the first side surface 2c of the main body 2, and second wiring 3B disposed on the second side surface 2d of the main body 2. In the following description, any wiring is represented by reference numeral 3. FIG. 1 shows the first side surface 2c of the main body 2 with the first wiring 3A shown with broken lines.
The main body 2 includes a plurality of layer portions stacked. In the present embodiment, in particular, the main body 2 includes at least nine layer portions. The plurality of layer portions included in the main body 2 include a plurality of pairs of layer portions stacked. Each of the plurality of pairs consists of two layer portions stacked. In the present embodiment, in particular, the plurality of layer portions included in the main body 2 are all in pairs. Therefore, in the present embodiment, the main body 2 includes at least five pairs of layer portions (at least ten layer portions).
By way of example, FIG. 1 and FIG. 2 show that the main body 2 includes five pairs of layer portions 11P, 12P, 13P, 14P and 15P arranged in this order from the top. A pair of layer portions 11P consists of an upper layer portion 11A and a lower layer portion 11B. A pair of layer portions 12P consists of an upper layer portion 12A and a lower layer portion 12B. A pair of layer portions 13P consists of an upper layer portion 13A and a lower layer portion 13B. A pair of layer portions 14P consists of an upper layer portion 14A and a lower layer portion 14B. A pair of layer portions 15P consists of an upper layer portion 15A and a lower layer portion 15B. In the following description, any pair of layer portions is represented by reference numeral 10P. The upper layer portion of any pair of layer portions 10P is represented by reference numeral 10A, and the lower layer portion of any pair of layer portions 10P is represented by reference numeral 10B. Any layer portion is represented by reference numeral 10. Two layer portions 10A and 10B constituting a pair of layer portions 10P are bonded to each other with an adhesive.
The main body 2 further includes a terminal layer 20 laid on the uppermost layer portion 11A. Every vertically adjacent two pairs of layer portions 10P are bonded to each other with an adhesive, and so are the layer portion 11A and the terminal layer 20 to each other. The layer portions 11A to 15B and the terminal layer 20 each have a top surface, a bottom surface, and four side surfaces. The terminal layer 20 includes a terminal layer main body 21 having a top surface and a bottom surface, and a plurality of pad-shaped terminals 22 disposed on the top surface of the terminal layer main body 21. The top surface of the terminal layer main body 21 constitutes the top surface 2a of the main body 2. The plurality of pad-shaped terminals 22 function as external connecting terminals of the layered chip package 1. Some of the pad-shaped terminals 22 each have an end face located at the side surface 2c of the main body 2, and the first wiring 3A is connected to these end faces. Some others of the pad-shaped terminals 22 each have an end face located at the side surface 2d of the main body 2, and the second wiring 3B is connected to these end faces.
The plurality of layer portions 10 included in the main body 2 include a plurality of first-type layer portions and at least one second-type layer portion. In the present embodiment, in particular, the number of the first-type layer portions included in the main body 2 is eight. The plurality of pairs of layer portions 10P included in the main body 2 include at least one specific pair of layer portions, the specific pair of layer portions consisting of one first-type layer portion and one second-type layer portion. In the following description, a specific pair of layer portions is represented by reference numeral 10PS. In the present embodiment, in particular, the plurality of pairs of layer portions 10P included in the main body 2 include a plurality of specific pairs of layer portions 10PS. In the present embodiment, in particular, the number of the specific pairs of layer portions 10PS included in the main body 2 is an even number.
FIG. 1 shows an example in which two pairs of layer portions 14P and 15P are the specific pairs of layer portions 10PS. In the pair of layer portions 14P, the layer portion 14A is the first-type layer portion and the layer portion 14B is the second-type layer portion. In the pair of layer portions 15P, the layer portion 15A is the first-type layer portion and the layer portion 15B is the second-type layer portion. In the example shown in FIG. 1, among the plurality of layer portions 10 included in the main body 2, eight layer portions 10 other than the layer portions 14B and 15B are the first-type layer portions. The difference between the first-type layer portion and the second-type layer portion will be described in detail later. FIG. 1 shows an example in which, in the specific pairs of layer portions 14P and 15P, the upper layer portions 14A and 15A are the first-type layer portions and the lower layer portions 14B and 15B are the second-type layer portions. However, in a specific pair of layer portion 10PS, the lower layer portion may be the first-type layer portion and the upper layer portion may be the second-type layer portion.
In the present embodiment, one of the plurality of specific pairs of layer portions 10PS included in the main body 2 is disposed closest to the top surface 2a or the bottom surface 2b of the main body 2 among the plurality of pairs of layer portions 10P included in the main body 2. In the example shown in FIG. 1, the specific pair of layer portions 15P is disposed closest to the bottom surface 2b of the main body 2 among the plurality of pairs of layer portions 10P included in the main body 2.
In the present embodiment, one of the plurality of specific pairs of layer portions 10PS included in the main body 2 is disposed farthest from the surface of the main body 2 on which the plurality of terminals 22 are disposed, among the plurality of pairs of layer portions 10P included in the main body 2. In the example shown in FIG. 1, the specific pair of layer portions 15P is disposed farthest from the top surface 2a of the main body 2 on which the plurality of terminals 22 are disposed, among the plurality of pairs of layer portions 10P included in the main body 2.
FIG. 3 is an exploded perspective view of the pair of layer portions 11P included in the layered chip package 1 shown in FIG. 1 and FIG. 2. As shown in FIG. 3, the layer portions 11A and 11B constituting the pair of layer portions 11P each include a semiconductor chip 30. The semiconductor chip 30 has: a first surface 30a having a device formed thereon; a second surface 30b opposite to the first surface 30a; a first side surface 30c and a second side surface 30d facing toward opposite directions; and a third side surface 30e and a fourth side surface 30f facing toward opposite directions. The side surfaces 30c, 30d, 30e and 30f respectively face toward the side surfaces 2c, 2d, 2e and 2f of the main body 2. The layer portions 11A and 11B are positioned such that the first surfaces 30a of their respective semiconductor chips 30 face toward each other.
Each of the layer portions 11A and 11B further includes: an insulating portion 31 covering at least one of the four side surfaces of the semiconductor chip 30; and a plurality of electrodes 32 connected to the semiconductor chip 30. The insulating portion 31 has at least one end face 31a located at the at least one of the side surfaces of the main body 2 on which the wiring is disposed. In the example shown in FIG. 3, the insulating portion 31 covers all of the four side surfaces of the semiconductor chip 30, and has four end faces 31a that are respectively located at the four side surfaces of the main body 2. In this example, the insulating portion 31 further covers the first surface 30a of the semiconductor chip 30.
In the example shown in FIG. 3, the plurality of electrodes 32 include a plurality of first electrodes 32A and a plurality of second electrodes 32B. Each of the plurality of first electrodes 32A has an end face 32Aa that is located at the first side surface 2c of the main body 2 and surrounded by the insulating portion 31. Each of the plurality of second electrodes 32B has an end face 32Ba that is located at the second side surface 2d of the main body 2 and surrounded by the insulating portion 31. In the following description, any electrode is represented by reference numeral 32, and the end face of any electrode 32 is represented by reference numeral 32a. 
Each of the pairs of layer portions 12P and 13P has the same configuration as the pair of layer portions 11P shown in FIG. 3. Each of the layer portions 14A and 15A, which are the first-type layer portions, has the same configuration as the layer portion 11A shown in FIG. 3. Each of the layer portions 14B and 15B, which are the second-type layer portions, does not include any electrode connected to the semiconductor chip 30 and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed. Consequently, as shown in FIG. 1, no end faces of electrodes are present at the side surfaces of the layer portions 14B and 15B. The remainder of the configuration of each of the layer portions 14B and 15B is the same as that of the layer portion 11B shown in FIG. 3.
The semiconductor chip 30 of the first-type layer portion 10 is a normally functioning one, whereas the semiconductor chip 30 of the second-type layer portion 10 is a malfunctioning one. Hereinafter, a normally functioning semiconductor chip 30 will be called a non-defective semiconductor chip 30, and a malfunctioning semiconductor chip 30 will be called a defective semiconductor chip 30. It should be noted that the second-type layer portion 10 may include any electrode or wiring other than one that is connected to the semiconductor chip 30 and has an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed. For example, the second-type layer portion 10 may include an electrode that is connected to the semiconductor chip 30 but does not have an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed, and/or wiring for connecting terminals of the semiconductor chip 30 to each other.
The first wiring 3A disposed on the first side surface 2c of the main body 2 is connected to the end faces 32Aa of the plurality of first electrodes 32A of the plurality of layer portions 10. The second wiring 3B disposed on the second side surface 2d of the main body 2 is connected to the end faces 32Ba of the plurality of second electrodes 32B of the plurality of layer portions 10.
The semiconductor chip 30 may be a memory chip constituting a memory such as a flash memory, DRAM, SRAM, MRAM, PROM or FeRAM. In this case, it is possible to implement a large-capacity memory through the use of the layered chip package 1 including a plurality of semiconductor chips 30. Furthermore, according to the layered chip package 1 of the present embodiment, it is possible to easily implement a memory of various capacities such as 64 GB (gigabytes), 128 GB and 256 GB by changing the number of the semiconductor chips 30 included in the layered chip package 1.
In the case where a semiconductor chip 30 includes a plurality of memory cells and where one or more of the memory cells are defective, the semiconductor chip 30 is non-defective if it can function normally by employing the redundancy technique.
The semiconductor chips 30 are not limited to memory chips, and may be for use for implementing other devices such as CPUs, sensors, and driving circuits for sensors. The layered chip package 1 according to the present embodiment is particularly suitable for implementing an SiP.
A method of manufacturing the layered chip package 1 according to the present embodiment will now be described. The method of manufacturing the layered chip package 1 according to the present embodiment includes the steps of: fabricating a layered substructure by stacking two substructures each of which includes a plurality of preliminary layer portions aligned, each of the preliminary layer portions being intended to become any one of the layer portions 10 included in the main body 2, the substructures being intended to be cut later at a boundary between every adjacent two of the preliminary layer portions; fabricating a pre-main-body stack by using the layered substructure, the pre-main-body stack being a stack of a predetermined two or greater number of pairs of layer portions 10P including at least one specific pair of layer portions; fabricating the main body 2 by stacking at least one additional first-type layer portion together with the pre-main-body stack, the number of the at least one additional first-type layer portion being equal to the number of the at least one specific pair of layer portions 10PS included in the pre-main-body stack; and completing the layered chip package 1 by forming the wiring 3 on the main body 2. In the present embodiment, in particular, the predetermined two or greater number mentioned above is four.
Reference is now made to FIG. 4 to FIG. 23 to describe in detail the step of fabricating the layered substructure in the method of manufacturing the layered chip package 1 according to the present embodiment. In the step of fabricating the layered substructure, first, a plurality of pre-substructure wafers are fabricated.
FIG. 4 shows the step of fabricating a single pre-substructure wafer. In this step, a semiconductor wafer 100 having a first surface 100a and a second surface 100b that face toward opposite directions is subjected to processing, such as a wafer process, at the first surface 100a, to thereby fabricate a pre-substructure wafer 101 which includes a plurality of pre-semiconductor-chip portions 30P aligned. The plurality of pre-semiconductor-chip portions 30P each include a device, and are to become the plurality of semiconductor chips 30 later. The plurality of pre-semiconductor-chip portions 30P of the pre-substructure wafer 101 may later become a plurality of semiconductor chips 30 of the same type. The pre-substructure wafer 101 has a first surface 101a corresponding to the first surface 100a of the semiconductor wafer 100, and a second surface 101b corresponding to the second surface 100b of the semiconductor wafer 100. In the pre-substructure wafer 101, the plurality of pre-semiconductor-chip portions 30P may be aligned in a row, or may be aligned in a plurality of rows such that a plurality of ones of the pre-semiconductor-chip portions 30P are aligned in each of vertical and horizontal directions. In the following description, it is assumed that the plurality of pre-semiconductor-chip portions 30P are aligned in a plurality of rows such that a plurality of ones of the pre-semiconductor-chip portions 30P are aligned in each of vertical and horizontal directions in the pre-substructure wafer 101.
The semiconductor wafer 100 may be a silicon wafer, for example. The wafer process is a process in which a wafer is processed into a plurality of devices that are not yet separated into a plurality of chips. In the pre-substructure wafer 101, the first surface 101a is a device formation surface on which devices are formed. Each of the plurality of pre-semiconductor-chip portions 30P has a plurality of pad-shaped terminals 34 disposed on the first surface 101a of the pre-substructure wafer 101.
FIG. 9 is a perspective view of the pre-substructure wafer 101. As shown in FIG. 9, the pre-substructure wafer 101 is provided with a plurality of scribe lines 102A and a plurality of scribe lines 102B. The scribe lines 102A extend horizontally to pass through boundaries between every two pre-semiconductor-chip portions 30P that are vertically adjacent to each other. The scribe lines 102B extend vertically to pass through boundaries between every two pre-semiconductor-chip portions 30P that are horizontally adjacent to each other. To facilitate understanding, FIG. 9 depicts the pre-semiconductor-chip portions 30P larger relative to the semiconductor wafer 100. For example, assuming that the semiconductor wafer 100 is a 12-inch wafer and a side of the top surface of each pre-semiconductor-chip portion 30 is 8 to 10 mm long, 700 to 900 pre-semiconductor-chip portions 30P are obtainable from a single semiconductor wafer 100.
FIG. 10 is a cross-sectional view illustrating an example of the internal structure of each pre-semiconductor-chip portion 30P of the pre-substructure wafer 101 of FIG. 9. Here is given an example in which a plurality of memory cells of a flash memory are formed as a device in the pre-semiconductor-chip portion 30P. FIG. 10 shows one of the plurality of memory cells as a device formed in the pre-semiconductor-chip portion 30P. The memory cell 40 includes a source 42 and a drain 43 formed near a surface of a P-type silicon substrate 41 composed of the semiconductor wafer 100, i.e., near the first surface 100a of the semiconductor wafer 100. The source 42 and the drain 43 are both N-type regions. The source 42 and the drain 43 are disposed at a predetermined distance from each other so that a channel composed of a portion of the P-type silicon substrate 41 is provided between the source 42 and the drain 43. The memory cell 40 further includes an insulating film 44, a floating gate 45, an insulating film 46 and a control gate 47 that are stacked in this order on the surface of the substrate 41 at the location between the source 42 and the drain 43. The memory cell 40 further includes an insulating layer 48 covering the source 42, the drain 43, the insulating film 44, the floating gate 45, the insulating film 46 and the control gate 47. The insulating layer 48 has contact holes that open at the tops of the source 42, the drain 43 and the control gate 47, respectively. The memory cell 40 includes a source electrode 52, a drain electrode 53, and a control gate electrode 57 that are formed on the insulating layer 48 at locations above the source 42, the drain 43 and the control gate 47, respectively. The source electrode 52, the drain electrode 53 and the control gate electrode 57 are connected to the source 42, the drain 43 and the control gate 47, respectively, through the respective contact holes.
A plurality of pre-substructure wafers 101 are each fabricated through the step described with reference to FIG. 4.
Next, a wafer sort test is performed on each of the plurality of pre-substructure wafers 101 to distinguish between a normally functioning pre-semiconductor-chip portion 30P and a malfunctioning pre-semiconductor-chip portion 30P among the plurality of pre-semiconductor-chip portions 30P included in each pre-substructure wafer 101. In the wafer sort test, a probe of a testing device is brought into contact with the terminals 34 of each pre-semiconductor-chip portion 30P and whether the pre-semiconductor-chip portion 30P functions normally or not is thereby tested with the testing device.
FIG. 5 shows the next step. In this step, first, a protection film 103 made of, for example, photoresist, is formed to cover the entire first surface 101a of the pre-substructure wafer 101. Next, at least one groove 104 is formed in the pre-substructure wafer 101. The at least one groove 104 opens at the first surface 101a of the pre-substructure wafer 101 and extends to be adjacent to at least one of the pre-semiconductor-chip portions 30P. Here, a plurality of grooves 104 are formed as shown in FIG. 5. At the positions of the boundaries between every two adjacent pre-semiconductor-chip portions 30P, the grooves 104 are formed to pass through the boundaries between every two adjacent pre-semiconductor-chip portions 30P. In this way, a pre-polishing substructure main body 105 is formed by the pre-substructure wafer 101 having undergone the formation of the plurality of grooves 104 therein. The pre-polishing substructure main body 105 includes the plurality of pre-semiconductor-chip portions 30P. The pre-polishing substructure main body 105 has a first surface 105a and a second surface 105b. The first surface 105a corresponds to the first surface 100a of the semiconductor wafer 100 and the first surface 101a of the pre-substructure wafer 101. The second surface 105b corresponds to the second surface 100b of the semiconductor wafer 100 and the second surface 101b of the pre-substructure wafer 101. The pre-polishing substructure main body 105 further has the plurality of grooves 104 that open at the first surface 105a. In the pre-polishing substructure main body 105, the first surface 105a is a device formation surface on which devices are formed.
The plurality of grooves 104 are formed along the scribe lines 102A and 102B shown in FIG. 9. The grooves 104 are formed such that their bottoms do not reach the second surface 101b of the pre-substructure wafer 101. The grooves 104 are each 10 to 150 μm wide, for example. The grooves 104 are each 30 to 150 μm deep, for example. The grooves 104 may be formed using a dicing saw, or by etching such as reactive ion etching.
FIG. 11 shows a portion of the pre-polishing substructure main body 105 fabricated in the step of FIG. 5. In the present embodiment, the plurality of grooves 104 include a plurality of first grooves 104A and a plurality of second grooves 104B. The first grooves 104A and the second grooves 104B extend in directions orthogonal to each other. FIG. 11 shows only one each of the first and second grooves 104A and 104B. The first grooves 104A are formed along the scribe lines 102A shown in FIG. 9, and the second grooves 104B are formed along the scribe lines 102B shown in FIG. 9.
FIG. 6 shows a step that follows the step of FIG. 5. In this step, first, an insulating layer 106 is formed to fill the plurality of grooves 104 of the pre-polishing substructure main body 105 and to cover the plurality of terminals 34. The insulating layer 106 will later become part of the insulating portion 31. Next, a plurality of openings 106a for exposing the terminals 34 are formed in the insulating layer 106.
The insulating layer 106 may be formed of a resin such as an epoxy resin or a polyimide resin. The insulating layer 106 may also be formed of a photosensitive material such as a polyimide resin containing a sensitizer. If the insulating layer 106 is formed of a photosensitive material, the openings 106a of the insulating layer 106 may be formed by photolithography. If the insulating layer 106 is formed of a non-photosensitive material, the openings 106a of the insulating layer 106 may be formed by selectively etching the insulating layer 106.
The insulating layer 106 may include a first layer that fills the grooves 104, and a second layer that covers the first layer and the terminals 34. In this case, the openings 106a are formed in the second layer. Both of the first layer and the second layer may be formed of a resin such as an epoxy resin or a polyimide resin. The second layer may be formed of a photosensitive material such as a polyimide resin containing a sensitizer. If the second layer is formed of a photosensitive material, the openings 106a may be formed in the second layer by photolithography. If the second layer is formed of a non-photosensitive material, the openings 106a may be formed in the second layer by selectively etching the second layer.
It is preferable that the insulating layer 106 be formed of a resin having a low thermal expansion coefficient. Forming the insulating layer 106 of a resin having a low thermal expansion coefficient serves to facilitate cutting of the insulating layer 106 when the insulating layer 106 is cut later with a dicing saw.
It is preferable that the insulating layer 106 be transparent. If the insulating layer 106 is transparent, it is possible to easily recognize alignment marks that will be formed on the insulating layer 106 later, through the insulating layer 106.
FIG. 7 shows a step that follows the step of FIG. 6. In this step, first, a photoresist layer is formed on the insulating layer 106 to cover the plurality of pre-semiconductor-chip portions 30P. The photoresist layer is intended to be used for forming the plurality of electrodes 32. The photoresist layer includes a plurality of portions corresponding to all the pre-semiconductor-chip portions 30P respectively. Each portion of the photoresist layer corresponding to a single pre-semiconductor-chip portion 30P covers not only the pre-semiconductor-chip portion 30P but also an area where electrodes 32 to be connected to the pre-semiconductor-chip portion 30P are located. Next, the photoresist layer is patterned by photolithography to thereby form a frame 108 having a plurality of grooves 108a to later accommodate the electrodes 32. The grooves 108a are not formed in a portion of the frame 108 corresponding to a malfunctioning pre-semiconductor-chip portion 30P. The step of forming the frame 108 will be described in detail later.
FIG. 8 shows a step that follows the step of FIG. 7. In this step, the electrodes 32 are formed in the grooves 108a of the frame 108 by, for example, plating. The electrodes 32 are formed such that part of each of the electrodes 32 lies on the insulating layer 106. The electrodes 32 are connected to the terminals 34 through the openings 106a. FIG. 12 shows a portion of the structure fabricated in the step of FIG. 8.
The electrodes 32 are formed of a conductive material such as Cu. In the case of forming the electrodes 32 by plating, a seed layer for plating is formed on the insulating layer 106 before forming the photoresist layer. Next, the photoresist layer is formed on the seed layer and patterned by photolithography to thereby form the frame 108. The photoresist layer is formed to be 10 to 20 μm thick, for example. Next, plating layers to become part of the electrodes 32 are formed by plating on the seed layer in the grooves of the frame 108. The plating layers are formed to be 5 to 15 μm thick, for example. Next, the frame 108 is removed and the seed layer except portions thereof located below the plating layers is also removed by etching. As a result, the electrodes 32 are formed of the plating layers and the portions of the seed layer remaining therebelow.
As shown in FIG. 12, in the step of forming the plurality of electrodes 32, a plurality of alignment marks 107 are formed on the insulating layer 106 simultaneously with the formation of the electrodes 32. The alignment marks 107 are disposed above the grooves 104. The material and forming method of the alignment marks 107 are the same as those of the electrodes 32.
A pre-polishing substructure 109 shown in FIG. 8 and FIG. 12 is thus fabricated. The pre-polishing substructure 109 includes: the pre-polishing substructure main body 105; the insulating layer 106 that fills the grooves 104 of the pre-polishing substructure main body 105 and that will later become part of the insulating portion 31; the plurality of electrodes 32 each having a portion lying on the insulating layer 106; and the plurality of alignment marks 107 disposed on the insulating layer 106. The pre-polishing substructure 109 has a first surface 109a and a second surface 109b. The first surface 109a corresponds to the first surface 100a of the semiconductor wafer 100 and the first surface 101a of the pre-substructure wafer 101. The second surface 109b corresponds to the second surface 100b of the semiconductor wafer 100 and the second surface 101b of the pre-substructure wafer 101.
A plurality of pre-polishing substructures 109 are each fabricated through the steps described with reference to FIG. 5 to FIG. 8.
The step of forming the frame 108 and the step of forming the plurality of electrodes 32 will now be described in detail with reference to FIG. 13 to FIG. 18. FIG. 13 shows a plurality of pre-substructure wafers 101. As previously described, the process of distinguishing between a normally functioning pre-semiconductor-chip portion 30P and a malfunctioning pre-semiconductor-chip portion 30P has been performed on the plurality of pre-semiconductor-chip portions 30P included in each pre-substructure wafer 101 by the wafer sort test. In FIG. 13, squares marked with “X” represent malfunctioning pre-semiconductor-chip portions 30P, and the remaining squares represent normally functioning pre-semiconductor-chip portions 30P. The wafer sort test provides location information on the normally functioning pre-semiconductor-chip portions 30P and the malfunctioning pre-semiconductor-chip portions 30P in each pre-substructure wafer 101. This location information will be used later in an exposure step for forming the frame 108.
FIG. 14 is an illustrative view showing an example of configuration of an exposure apparatus used in the method of manufacturing the layered chip package 1 according to the present embodiment. The exposure apparatus shown in FIG. 14 is a stepping projection exposure apparatus, or a so-called stepper. This exposure apparatus includes: a mask stage 210 for retaining a mask 201; a driving device 211 for driving the mask stage 210 to move or replace the mask 201; a wafer stage 220 for retaining a wafer 202; a moving mechanism 221 for moving the wafer stage 220; a driving device 222 for driving the moving mechanism 221; a reduction projection optical system 203; an illumination device 204; a detection device 240 for detecting the location of the wafer 202; and a control device 250 for controlling the illumination device 204, the driving devices 211 and 222 and the detection device 240.
The mask stage 210 is disposed above the wafer stage 220. The reduction projection optical system 203 is disposed between the mask stage 210 and the wafer stage 220. The illumination device 204 is disposed above the mask stage 210 and applies light for exposure to the mask 201.
The moving mechanism 221 is capable of moving the wafer stage 220 in X, Y and Z directions shown in FIG. 14 and capable of changing the angle of inclination of the wafer stage 220 with respect to the X-Y plane. The X direction and the Y direction are orthogonal to each other and are both orthogonal to the direction of the optical axis of the reduction projection optical system 203. The Z direction is parallel to the direction of the optical axis of the reduction projection optical system 203. The detection device 240 detects the location of the surface of the wafer 202 and the angle of inclination of the surface of the wafer 202 with respect to the X-Y plane.
The control device 250 has a microprocessor unit (MPU), read only memory (ROM) and random access memory (RAM).
When exposing the wafer 202 using this exposure apparatus, a plurality of pattern projection regions are defined on the surface of the wafer 202. A ray bundle emitted from the illumination device 204 passes through the mask 201 and is applied to one of the pattern projection regions by the reduction projection optical system 203. The mask pattern of the mask 201 is thereby projected onto the one of the pattern projection regions through the reduction projection optical system 203, so that the process of exposing the one of the pattern projection regions is performed. After performing the process of exposing the one of the pattern projection regions based on the mask pattern, the exposure apparatus moves the wafer 202 in the X or Y direction, and performs the same exposure process for a next one of the pattern projection regions.
In the step of forming the frame 108 of the present embodiment, first, a photoresist layer is formed on the insulating layer 106 to cover the plurality of pre-semiconductor-chip portions 30P of the structure shown in FIG. 6. In the present embodiment, the photoresist layer is negative-working. In the negative-working photoresist layer, the areas irradiated with light become insoluble in a developing solution while the unirradiated areas are soluble in the developing solution. Next, the photoresist layer is patterned by photolithography to thereby form the frame 108. When forming the frame 108, the exposure apparatus shown in FIG. 14 is used for exposing the photoresist layer. In this case, the structure of FIG. 6 with the photoresist layer formed thereon is the wafer 202 of FIG. 14. A plurality of pattern projection regions are defined on portions of the surface of the photoresist layer that correspond to the plurality of pre-semiconductor-chip portions 30P. The size of each pattern projection region is designed to be slightly larger than the top surface of the pre-semiconductor-chip portion 30P so as to cover the area where the electrodes 32 are to be formed. The location information on the normally functioning and malfunctioning pre-semiconductor-chip portions 30P in each pre-substructure wafer 101 obtained by the wafer sort test is input to and held by the control device 250 when the photoresist layer of the wafer 202 corresponding to the pre-substructure wafer 101 is exposed. The control device 250 can replace the mask 201 based on the location information.
The exposure step of exposing the photoresist layer for forming the frame 108 of the present embodiment will now be described with reference to the flow chart of FIG. 15. In this exposure step, the photoresist layer is exposed such that a latent image corresponding to the plurality of electrodes 32 is formed on a portion of the photoresist layer corresponding to a normally functioning pre-semiconductor-chip portion 30P whereas any latent image corresponding to an electrode connected to a malfunctioning pre-semiconductor-chip portion 30P and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed is not formed on a portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion 30P. In this exposure step, first, among the plurality of pattern projection regions corresponding to the plurality of pre-semiconductor-chip portions 30P, a pattern projection region corresponding to a first pre-semiconductor-chip portion 30P is selected to be exposed by the exposure apparatus of FIG. 14 (Step S101). Next, the control device 250 judges whether the pre-semiconductor-chip portion 30P corresponding to the selected pattern projection region is a normally functioning one or not (Step S102).
If the pre-semiconductor-chip portion 30P is judged as a normally functioning one (Y) in Step S102, the portion of the photoresist layer corresponding to the normally functioning pre-semiconductor-chip portion 30P is exposed in a pattern corresponding to the plurality of electrodes 32 (hereinafter referred to as an electrode pattern) through a mask 201 having the electrode pattern (Step S103). Specifically, the electrode pattern is configured to disallow light to be applied to an area of the pattern projection region where to form the grooves 108a to later accommodate the electrodes 32 and to allow light to be applied to the remaining area of the pattern projection region. As a result of this exposure, a latent image corresponding to the plurality of electrodes 32 is formed on the portion of the photoresist layer corresponding to the normally functioning pre-semiconductor-chip portion 30P. To be more specific, in the portion of the photoresist layer corresponding to a normally functioning pre-semiconductor-chip portion 30P, the area where to form the grooves 108a to later accommodate the electrodes 32 is soluble in a developing solution while the remaining area becomes insoluble in the developing solution upon this exposure.
If the pre-semiconductor-chip portion 30P is judged as a malfunctioning one (N) in Step S102, the portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion 30P is subjected to an overall exposure through a mask 201 that entirely passes light, or without using a mask 201 (Step S104). As a result, any latent image corresponding to an electrode connected to the malfunctioning pre-semiconductor-chip portion 30P and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed is not formed on the portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion 30P. Specifically, the entire portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion 30P becomes insoluble in the developing solution. In the case where the second-type layer portion 10 includes an electrode or wiring other than one that is connected to the malfunctioning semiconductor chip 30 and that has an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed, an exposure is performed in Step S104 such that a latent image corresponding to such an electrode or wiring is formed, instead of the overall exposure. In this case also, any latent image corresponding to an electrode connected to the malfunctioning pre-semiconductor-chip portion 30P and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed is not formed on the portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion 30P.
After the Step S103 or S104 is performed, the control device 250 judges whether the pattern projection region having undergone the exposure in Step S103 or S104 is the region corresponding to the last pre-semiconductor-chip portion 30P (Step S105). If the pattern projection region is judged as corresponding to the last pre-semiconductor-chip portion 30P (Y), the exposure step is finished. If the pattern projection region is judged as not corresponding to the last pre-semiconductor-chip portion 30P (N), a pattern projection region corresponding to a next pre-semiconductor-chip portion 30P is selected to be exposed (Step S106) and the process starting from Step S102 is repeated.
FIG. 16 is an illustrative view showing the exposure step of FIG. 15. Reference numeral 108P in FIG. 16 indicates the photoresist layer to be used for forming the frame 108. Portions (a), (b), (c) and (d) of FIG. 16 indicate regions for which Step S103 or S104 is to be performed. In the example of FIG. 16, Step S103 or S104 is performed in the order of the regions (a), (b), (c) and (d). For the regions (a), (c) and (d), the corresponding pre-semiconductor-chip portions 30P have been judged as normally functioning ones in Step S102 and consequently the portions of the photoresist layer 108P corresponding to those normally functioning pre-semiconductor-chip portions 30P are each exposed in the electrode pattern through a mask 201A having the electrode pattern. For the region (b), the corresponding pre-semiconductor-chip portion 30P has been judged as a malfunctioning one in Step S102 and consequently the portion of the photoresist layer 108P corresponding to the malfunctioning pre-semiconductor-chip portion 30P is subjected to an overall exposure through a mask 201B that entirely passes light (or without using any mask 201). Portion (e) of FIG. 16 shows the plane geometry of the latent image formed on the photoresist layer 108P by exposure.
After the exposure step described above, the photoresist layer 108P is developed with a developing solution and the frame 108 is thereby formed. FIG. 17 shows the frame 108 formed by development. Regions (a), (b), (c) and (d) of FIG. 17 correspond to the regions (a), (b), (c) and (d) of FIG. 16. In FIG. 17, in the regions (a), (c) and (d) the grooves 108a are formed in the frame 108, whereas in the region (b), grooves 108a are not formed in the frame 108. Portion (e) of FIG. 17 shows the plane geometries of the grooves 108a. 
Next, the electrodes 32 are formed in the grooves 108a of the frame 108 by, for example, plating, and then the frame 108 is removed. FIG. 18 shows the electrodes 32 thus formed. Regions (a), (b), (c) and (d) of FIG. 18 correspond to the regions (a), (b), (c) and (d) of FIG. 16. In FIG. 18 the electrodes 32a are formed in the regions (a), (c) and (d), whereas in the region (b) there are not formed any electrode connected to the pre-semiconductor-chip portion 30P. Portion (e) of FIG. 18 shows the plane geometries of the electrodes 32a. 
Steps following the formation of the electrodes 32 will now be described. FIG. 19 shows a step that follows the step of FIG. 8. In this step, two pre-polishing substructures 109 are bonded to each other with an insulating adhesive such that their respective first surfaces 109a face toward each other. A stack including the two pre-polishing substructures 109 is thereby fabricated. An insulating layer 111 formed by the adhesive covers the electrodes 32 and will become part of the insulating portion 31. It is preferred that the insulating layer 111 be transparent. Hereinafter, the lower one of the two pre-polishing substructures 109 shown in FIG. 19 will be called a first pre-polishing substructure 109. The pre-substructure wafer 101 serving as a base for fabricating the first pre-polishing substructure 109 will be hereinafter called a first pre-substructure wafer 101. The upper one of the two pre-polishing substructures 109 shown in FIG. 19 will be hereinafter called a second pre-polishing substructure 109. The pre-substructure wafer 101 serving as a base for fabricating the second pre-polishing substructure 109 will be hereinafter called a second pre-substructure wafer 101.
Next, both surfaces of the stack shown in FIG. 19, that is, the second surface 109b of the first pre-polishing substructure 109 and the second surface 109b of the second pre-polishing substructure 109, are polished. This polishing is performed until the plurality of grooves 104 become exposed. In FIG. 19 the broken lines indicate the positions of the second surfaces 109b after the polishing.
FIG. 20 shows the stack having undergone the polishing of both surfaces as described above. As a result of polishing the second surface 109b of the first pre-polishing substructure 109, the first pre-polishing substructure 109 is thinned by the polishing and thereby a substructure 110 is formed. This substructure 110 will be hereinafter called a first substructure 110. Similarly, as a result of polishing the second surface 109b of the second pre-polishing substructure 109, the second pre-polishing substructure 109 is thinned by the polishing and thereby a substructure 110 is formed. This substructure 110 will be hereinafter called a second substructure 110. Each of the first and second substructures 110 has a thickness of, for example, 30 to 100 μm. Each substructure 110 has a first surface 110a corresponding to the first surface 109a of the pre-polishing substructure 109, and a second surface 110b opposite to the first surface 110a. The second surface 110b is the polished surface.
In the step of polishing both surfaces of the stack including the two substructures 109 as above, after one of the two surfaces of the stack is polished, a plate-shaped jig 112 shown in FIG. 20 is bonded to the polished surface and then the other surface is polished. Bonding the jig 112 to the polished surface of the stack facilitates handling of the stack and prevents the stack from being damaged in a subsequent step. If the insulating layers 106 and 111 are transparent, using a transparent jig such as an acrylic plate or a glass plate as the jig 112 allows the alignment marks 107 of the two substructures 110 included in the stack to be visible through the jig 112 and the insulating layers 106 and 111, all of which are transparent. This makes it easy to perform alignment of two or more of the stacks of FIG. 20 using the alignment marks 107 when stacking the two or more of the stacks, as will be described later.
Polishing both surfaces of the stack including the two pre-polishing substructures 109 produces a layered substructure 114, which is a stack of two substructures 110, as shown in FIG. 20.
FIG. 21 shows a portion of the substructure 110 fabricated in the step of FIG. 20. As previously described, by polishing the second surface 109b of the pre-polishing substructure 109 until the grooves 104 become exposed, the plurality of pre-semiconductor-chip portions 30P are separated from each other and thereby become the semiconductor chips 30. The first surface 30a of each semiconductor chip 30 corresponds to the first surface 100a of the semiconductor wafer 100, and the second surface 30b of each semiconductor chip 30 corresponds to the second surface 100b of the semiconductor wafer 100. The plurality of terminals 34 of each semiconductor chip 30 are disposed on the first surface 30a. 
The substructure 110 includes a plurality of preliminary layer portions 110c aligned, and is to be cut later at a boundary between every adjacent two of the preliminary layer portions 110c. Each of the plurality of preliminary layer portions 110c is to become any one of the layer portions 10 included in the main body 2. The substructure 110 is cut along the scribe lines 102A and 102B shown in FIG. 9. In the substructure 110, each of the plurality of preliminary layer portions 110c is therefore a portion surrounded by two adjacent scribe lines 102A and two adjacent scribe lines 102B.
Reference is made to FIG. 22 and FIG. 23 to describe an example of the layout of the terminals 34 and the electrodes 32 in the first substructure 110 and the layout of the terminals 34 and the electrodes 32 in the second substructure 110. FIG. 22 shows the terminals 34 and the electrodes 32 of the first substructure 110 as seen from the first surface 110a of the first substructure 110. FIG. 23 shows the terminals 34 and the electrodes 32 of the second substructure 110 as seen from the second surface 110b of the second substructure 110. The substructures 110 will be cut later along the scribe lines 102A shown in FIG. 22 and FIG. 23, and this will form the end face of each of the electrodes 32 located at one of the side surfaces of the main body 2.
Each of the semiconductor chips 30 included in the first substructure 110 shown in FIG. 22 will be hereinafter called a first semiconductor chip 30. Each of the semiconductor chips 30 included in the second substructure 110 shown in FIG. 23 will be hereinafter called a second semiconductor chip 30.
As shown in FIG. 22, the first semiconductor chip 30 includes a plurality of first terminals 34 aligned in a predetermined order. Here, among the plurality of first terminals 34, attention is focused on nine terminals aligned along one side of the first surface 30a of the semiconductor chip 30, as shown in FIG. 22. In FIG. 22 the nine terminals are indicated with reference characters A to I. In the first semiconductor chip 30, the terminals A to I are aligned in a row in the order of A to I in the direction from left to right in FIG. 22.
The second semiconductor chip 30 shown in FIG. 23 includes a plurality of second terminals 34 aligned in a predetermined order in correspondence with the first terminals 34 of the first semiconductor chip 30 of FIG. 22. In particular, the second semiconductor chip 30 includes terminals A to I that respectively correspond to the terminals A to I of the first semiconductor chip 30 and that are aligned similarly to the terminals A to I of the first semiconductor chip 30. As seen from the first surface 30a of the semiconductor chip 30, the order in which the terminals A to I are aligned is the same between the first and second semiconductor chips 30. However, under the condition in which the first and second semiconductor chips 30 are positioned such that their respective first surfaces 30a face toward each other, as seen in one direction, such as in the direction from the second surface 30b of the second semiconductor chip 30, the order in which the terminals A to I of the second semiconductor chip 30 are aligned is the reverse of the order in which the terminals A to I of the first semiconductor chip 30 are aligned, as shown in FIG. 22 and FIG. 23.
Here, among the end faces of the plurality of electrodes 32 to be formed later at the positions of the scribe lines 102A shown in FIG. 22 and FIG. 23, those corresponding to the terminals A to I of the semiconductor chip 30 are also indicated with reference characters A to I. In the first substructure 110, as seen in one direction, the end faces A to I of the electrodes 32 to be formed at the positions of the scribe lines 102A are aligned in the same order as the order in which the corresponding terminals A to I are aligned, as shown in FIG. 22. In other words, the plurality of electrodes 32 of the first substructure 110 are formed in such a pattern that the order in which the end faces A to I of the electrodes 32 are aligned is the same as the order in which the corresponding terminals A to I are aligned.
In contrast, in the second substructure 110, as seen in one direction, the end faces A to I of the electrodes 32 to be formed at the positions of the scribe lines 102A are aligned in the reverse order to the order in which the corresponding terminals A to I are aligned, as shown in FIG. 23. In other words, the plurality of electrodes 32 of the second substructure 110 are formed in such a pattern that the order in which the end faces A to I of the electrodes 32 are aligned is the reverse of the order in which the corresponding terminals A to I are aligned.
In the layered chip package 1 fabricated by using the layered substructure 114 including the first and second substructures 110 shown in FIG. 22 and FIG. 23, as seen in one direction, the order in which the terminals A to I of the second semiconductor chip 30 are aligned is the reverse of the order in which the terminals A to I of the first semiconductor chip 30 are aligned. The end faces of electrodes 32 that are located at one side surface of the main body 2 and connected to the terminals A to I of the first semiconductor chip 30 are aligned in the same order as the order in which the corresponding terminals A to I are aligned, whereas the end faces of electrodes 32 that are located at one side surface of the main body 2 and connected to the terminals A to I of the second semiconductor chip 30 are aligned in the reverse order to the order in which the corresponding terminals A to I are aligned. As a result, at one side surface of the main body 2, the end faces of electrodes 32 that are connected to the terminals A to I of the first semiconductor chip 30 and the end faces of electrodes 32 that are connected to the terminals A to I of the second semiconductor chip 30 are aligned in the same order.
A case will now be considered where, in a pair of layer portions 10P included in the layered chip package 1, the first and second semiconductor chips 30 having the terminals 34 aligned in the same manner are positioned such that the respective first surfaces 30a face toward each other and corresponding terminals 34 of the first and second semiconductor chips 30 are connected to each other. In this case, according to the example of the layouts of the terminals 34 and the electrodes 32 of the first and second substructures 110 shown in FIG. 22 and FIG. 23, the end faces of electrodes 32 that are connected to the terminals 34 of the first semiconductor chip 30 and the end faces of electrodes 32 that are connected to the terminals 34 of the second semiconductor chip 30 are aligned in the same order at one side surface of the main body 2. This makes it possible to easily connect the corresponding terminals 34 of the first and second semiconductor chips 30 to each other through the wiring 3.
While the foregoing description has been made concerning the terminals 34 aligned along one side of the first surface 30a of the semiconductor chip 30 shown in each of FIG. 22 and FIG. 23 and the electrodes 32 connected to those terminals 34, the same applies to other terminals 34 aligned along the opposite side to the foregoing side and electrodes 32 connected to those terminals 34.
The step of fabricating the pre-main-body stack will now be described with reference to FIG. 24 to FIG. 26. Here, a first to a third example of the step of fabricating the pre-main-body stack will be described.
FIG. 24 is an illustrative view showing the first example of the step of fabricating the pre-main-body stack. According to the first example, first, the layered substructure 114 shown in portion (a) of FIG. 24 is cut into at least one bar 115 shown in portion (b) of FIG. 24. The bar 115 includes a plurality of portions 115a aligned in one direction orthogonal to the stacking direction of the layer portions 10. Each of the plurality of portions 115a is to become any one of the plurality of pairs of layer portions 10P included in the main body 2. Next, the at least one bar 115 is cut into a plurality of pairs of layer portions 10P, each of the plurality of pairs being intended to become any one of the plurality of pairs of layer portions 10P included in the main body 2. Portion (c) of FIG. 24 shows one pair of layer portions 10P. Next, a predetermined two or greater number (in the present embodiment, four) of pairs of layer portions 10P are stacked and every vertically adjacent pairs of layer portions 10P are bonded to each other. The pre-main-body stack 118 shown in portion (d) of FIG. 24 is thereby completed.
FIG. 25 is an illustrative view showing the second example of the step of fabricating the pre-main-body stack. According to the second example, first, the layered substructure 114 shown in portion (a) of FIG. 25 is cut into at least one bar 115 shown in portion (b) of FIG. 25. Next, as shown in portion (c) of FIG. 25, two or more bars 115 as many as the predetermined two or greater number (in the present embodiment, four) are stacked and every vertically adjacent bars 115 are bonded to each other to thereby fabricate a bar stack 116. The bar stack 116 includes a plurality of portions 116a aligned in one direction orthogonal to the stacking direction of the layer portions 10. Each of the plurality of portions 116a is to become the pre-main-body stack 118. Next, as shown in portion (d) of FIG. 25, the pre-main body stack 118 is completed by cutting the bar stack 116.
FIG. 26 is an illustrative view showing the third example of the step of fabricating the pre-main-body stack. According to the third example, first, a number of layered substructures 114 shown in portion (a) of FIG. 26 as many as the predetermined two or greater number (in the present embodiment, four) are stacked and every vertically adjacent layered substructures 114 are bonded to each other to thereby fabricate a stack aggregate 117 as shown in portion (b) of FIG. 26. The stack aggregate 117 includes a plurality of portions each of which is to become the pre-main-body stack 118. The plurality of portions are aligned in two directions orthogonal to the stacking direction of the layer portions 10. Next, the stack aggregate 117 is cut into the bar stack 116 as shown in portion (c) of FIG. 26. Next, as shown in portion (d) of FIG. 26, the pre-main-body stack 118 is completed by cutting the bar stack 116.
The terminal layer 20 is stacked on and bonded to the pre-main-body stack 118 fabricated through any of the first to third examples. This step is the step of forming the plurality of terminals 22. The terminal layer 20 is formed by, for example, cutting a terminal wafer 120 shown in FIG. 27. The terminal wafer 120 has a wafer main body 121 that is plate-shaped and formed of an insulating material such as a resin or ceramic. The wafer main body 121 includes a plurality of pre-terminal-layer-body portions 21P that will be separated from each other later to thereby become the terminal layer main bodies 21. The terminal wafer 120 further includes a plurality of groups of pad-shaped terminals 22 disposed on the top surface of the wafer main body 121. One each group of pad-shaped terminals 22 is disposed in each pre-terminal-layer-body portion 21P. At the boundaries between every two adjacent pre-terminal-layer-body portions 21P, pad-shaped terminals 22 disposed in one of the two adjacent pre-terminal-layer-body portions 21P may be either coupled or non-coupled to those disposed in the other of the two adjacent pre-terminal-layer-body portions 21P. The wafer main body 121 may be transparent. In this case, alignment marks may be provided on the top surface of the wafer main body 121 at the positions of the boundaries between every two adjacent pre-terminal-layer-body portions 21P.
In the second example of the step of fabricating the pre-main-body stack shown in FIG. 25, the terminal wafer 120 may be cut into a terminal bar in which a plurality of portions to become the terminal layers 20 are aligned in one direction, and this terminal bar may be bonded onto the bar stack 116 shown in portion (c) of FIG. 25. In this case, by cutting the bar stack 116 with the terminal bar bonded thereonto, it is possible to form the pre-main-body stack 118 with the terminal layer 20 bonded thereonto.
In the third example of the step of fabricating the pre-main-body stack shown in FIG. 26, the terminal wafer 120 may be bonded onto the stack aggregate 117 shown in portion (b) of FIG. 26. In this case, by cutting the stack aggregate 117 with the terminal wafer 120 bonded thereonto, it is possible to form the pre-main-body stack 118 with the terminal layer 20 bonded thereonto.
In any of the first to third examples of the step of fabricating the pre-main-body stack, the pre-main-body stack 118 is fabricated by using the layered substructure 114 formed by stacking two substructures 110.
The step of fabricating the main body 2 will now be described. In the present embodiment, since each substructure 110 is fabricated by using the pre-substructure wafer 101 that can include a malfunctioning pre-semiconductor-chip portion 30P as shown in FIG. 13, the pre-main-body stack 118 can include a second-type layer portion 10 which includes a defective semiconductor chip 30. The second-type layer portion 10 is identifiable from the information obtained by the wafer sort test. In the present embodiment, any pair of two layer portions 10P both of which are the second-type layer portions 10 is not used for fabrication of the pre-main-body stack 118. Instead, a specific pair of layer portions 10PS which consists of a first-type layer portion 10 and a second-type layer portion 10 is used for fabrication of the pre-main-body stack 118. Consequently, the pre-main-body stack 118 can include at least one specific pair of layer portions 10PS.
In the step of fabricating the main body 2, first, the number of the specific pair(s) of layer portions 10PS included in the pre-main-body stack 118 is identified from the information obtained by the wafer sort test. When the number of the specific pair(s) of layer portions 10PS included in the pre-main-body stack 118 is zero, in other words, when all of the plurality of pairs of layer portions 10P included in the pre-main-body stack 118 each consist of two first-type layer portions, the structure made up of the pre-main-body stack 118 and the terminal layer 20 bonded thereonto functions as the main body 2. FIG. 28 shows such a main body 2 made up of the terminal layer 20 and the pre-main-body stack 118 that does not include any specific pair of layer portions 10PS as described above. The wiring 3 is to be formed later for this main body 2. A layered chip package that does not include any defective semiconductor chip 30 is thereby completed.
The method of manufacturing a layered chip package according to the present embodiment applies for the case where the pre-main-body stack 118 includes at least one specific pair of layer portions 10PS. FIG. 29 is an illustrative view showing the step of fabricating the main body in the method of manufacturing the layered chip package according to the present embodiment. As shown in FIG. 29, in the method of manufacturing the layered chip package according to the present embodiment, the main body 2 is fabricated by stacking at least one additional first-type layer portion 10 together with the pre-main-body stack 118, the number of the at least one additional first-type layer portion 10 being equal to the number of the at least one specific pair of layer portions 10PS included in the pre-main-body stack 118. In the present embodiment, in particular, the main body 2 is fabricated by stacking at least one additional specific pair of layer portions 10PS together with the pre-main-body stack 118, the number of the at least one additional specific pair of layer portions 10PS being equal to the number of the at least one specific pair of layer portions 10PS included in the pre-main-body stack 118. The at least one additional specific pair of layer portions 10PS is formed by cutting the layered substructure 114.
The example shown in FIG. 29 corresponds to the example shown in FIG. 1. Specifically, in the example shown in FIG. 29, the pre-main-body stack 118 includes three pairs of layer portions 11P, 12P and 13P in each of which both of the two layer portions 10 are the first-type layer portions 10, and a pair of layer portions 14P that is a specific pair of layer portions 10PS. In this example, the pre-main-body stack 118 and a pair of layer portions 15P, which is an additional specific pair of layer portions 10PS, are stacked together and bonded to each other to thereby fabricate the main body 2. In this example, among the plurality of pairs of layer portions 10P included in the main body 2, the additional specific pair of layer portions 15P is disposed farthest from the top surface 2a of the main body 2 on which the plurality of terminals 22 are disposed, or in other words, disposed closest to the bottom surface 2b of the main body 2. In this way, as shown in FIG. 1, the main body 2 including two specific pairs of layer portions 10PS is fabricated.
When the pre-main-body stack 118 includes two or more specific pairs of layer portions 10PS, the main body 2 is fabricated by stacking two or more additional specific pairs of layer portions 10PS together with the pre-main-body stack 118, the number of the two or more additional specific pairs of layer portions 10PS being equal to the number of the two or more specific pairs of layer portions 10PS included in the pre-main-body stack 118. As thus described, according to the present embodiment, the main body 2 is fabricated by stacking at least one additional specific pair of layer portions 10PS together with the pre-main-body stack 118, the number of the at least one additional specific pair of layer portions 10PS being equal to the number of the at least one specific pair of layer portions 10PS included in the pre-main-body stack 118. Consequently, the number of the specific pairs of layer portions 10PS included in the main body 2 is always an even number.
FIG. 30 is a perspective view showing a side surface of a layer portion 10 included in the main body 2. In the step of fabricating the pre-main-body stack 118 and the step of fabricating an additional specific pair of layer portions 10PS, the insulating layers 106 and 111 are cut such that the respective cut surfaces are formed along each of the direction in which the first groove 104A of FIG. 21 extends and the direction in which the second groove 104B of FIG. 21 extends. As shown in FIG. 30, the insulating layer 106 becomes an insulating layer 31A by being cut. The insulating layer 31A is part of the insulating portion 31. In addition, part of the end face 31a of the insulating portion 31 is formed by the cut surface of the insulating layer 106, that is, a cut surface 31Aa of the insulating layer 31A. The insulating layer 111 becomes an insulating layer 31B by being cut. The insulating layer 31B is another part of the insulating portion 31. In addition, another part of the end face 31a of the insulating portion 31 is formed by the cut surface of the insulating layer 111, that is, a cut surface 31Ba of the insulating layer 31B. By cutting the insulating layers 106 and 111, the end faces 32a of the plurality of electrodes 32 are exposed from the end face 31a of the insulating portion 31. The end faces 32a are surrounded by the insulating portion 31.
A description will now be given of the step of completing the layered chip package 1 by forming the wiring 3 on the main body 2. In this step, first, polishing is performed on the two side surfaces of the main body 2 at which the end faces 32a of the electrodes 32 appear. Next, wiring 3A, 3B is formed on the main body 2.
The step of completing the layered chip package 1 may be performed for a plurality of main bodies 2 simultaneously in the following manner, for example. In this example, first, as shown in FIG. 31, a plurality of main bodies 2 are aligned using, e.g., a chip bonding apparatus, such that the respective side surfaces on which the wiring 3A is to be formed face upward. At this time, the plurality of main bodies 2 thus aligned may be fixed by being bonded to each other such that they are separable easily. Next, the respective side surfaces of the plurality of main bodies 2 on which the wiring 3A is to be formed are polished simultaneously. Next, the wiring 3A is formed on the respective side surfaces of the plurality of main bodies 2 on which the wiring 3A is to be formed. Next, the plurality of main bodies 2 are aligned such that the respective side surfaces on which the wiring 3B is to be formed face upward. Then, the respective side surfaces of the plurality of main bodies 2 on which the wiring 3B is to be formed are polished simultaneously, and the wiring 3B is formed on these respective side surfaces.
When aligning the plurality of main bodies 2, it is possible to recognize and control the position of each main body 2 by recognizing the position of an edge of each main body 2 and/or the positions of the end faces 32a of the electrodes 32 that appear at the side surface of each main body 2 through the use of an image recognizer included in the chip bonding apparatus.
The wiring 3A, 3B is formed by frame plating, for example. In this case, first, a seed layer for plating is formed on the side surface of the main body 2 on which the wiring 3A is to be formed. Next, a frame having grooves is formed on the seed layer. The frame is formed by patterning a photoresist film by photolithography, for example. Next, plating layers to become part of the wiring 3A are formed by plating on the seed layer in the grooves of the frame. Next, the frame is removed and the seed layer except portions thereof located below the plating layers is removed by etching. As a result, the wiring 3A is formed of the plating layers and the portions of the seed layer remaining therebelow. Next, the wiring 3B is formed in the same way as the wiring 3A on the side surface of the main body 2 on which the wiring 3B is to be formed.
The layered chip package 1 is completed in the above-described manner. FIG. 32 shows a layered chip package 1 manufactured by forming the wiring 3 on a main body 2 that does not include any specific pair of layer portions 10PS as shown in FIG. 28. Forming the wiring 3 on a main body 2 fabricated through the step of FIG. 29 produces a layered chip package 1 that includes specific pairs of layer portions 14P and 15P, as shown in FIG. 1 and FIG. 2.
In the second and third examples of the step of fabricating the pre-main-body stack shown in FIG. 25 and FIG. 26, the bar stack 116 shown in portion (c) of each of FIG. 25 and FIG. 26 may be subjected to polishing of the two side surfaces of each portion 116a at which the end faces 32a of the electrodes 32 appear. In this case, for the additional specific pair(s) of layer portions 10PS to be later stacked together with the pre-main-body stack 118, polishing of the two side surfaces at which the end faces 32a of the electrodes 32 appear is performed before stacking the additional specific pair(s) of layer portions together with the pre-main-body stack 118.
The layered chip package 1 according to the present embodiment is usable as it is as a single electronic component. For example, the layered chip package 1 can be mounted on a wiring board by a flip-chip technique by placing the layered chip package 1 on the wiring board such that the plurality of pad-shaped terminals 22 face downward.
For example, if a device for use with the layered chip package 1 has a recessed portion to accommodate the layered chip package 1, the layered chip package 1 can be inserted to the recessed portion such that the plurality of pad-shaped terminals 22 face upward. It is thereby possible to connect the pad-shaped terminals 22 to circuits in the device.
FIG. 33 shows an example of use of the layered chip package 1. In this example, a plurality of bonding wires 160 are connected at their respective one ends to the plurality of pad-shaped terminals 22 of the layered chip package 1. The respective other ends of the plurality of bonding wires 160 are connected to terminals of a device for use with the layered chip package 1.
FIG. 34 and FIG. 35 show other examples of use of the layered chip package 1. In each of these examples, the layered chip package 1 is mounted to a lead frame having a plurality of pins 161 and is sealed with a molded resin. The plurality of pad-shaped terminals 22 of the layered chip package 1 are connected to the plurality of pins 161. The molded resin forms a protection layer 162 for protecting the layered chip package 1. FIG. 34 shows an example in which the plurality of pins 161 extend horizontally. FIG. 35 shows an example in which the plurality of pins 161 are folded downward.
In the example shown in FIG. 1 and FIG. 2, among the plurality of pairs of layer portions 10P included in the main body 2, one of the additional specific pairs of layer portions 10PS (the pair of layer portions 15P) is disposed closest to the bottom surface 2b of the main body 2. Alternatively, among the plurality of pairs of layer portions 10P included in the main body 2, one of the additional specific pairs of layer portions 10PS may be disposed closest to the top surface 2a of the main body 2, in other words, may be disposed below the terminal layer 20.
FIG. 36 is a perspective view showing a modification example of the layered chip package 1 according to the present embodiment. According to this modification example, the terminal layer 20 is disposed closer to the bottom surface 2b of the main body 2 than are the plurality of pairs of layer portions 10P included in the main body 2. In this modification example, among the plurality of pairs of layer portions 10P included in the main body 2, one of the additional specific pairs of layer portions 10PS may be disposed farthest from the surface of the main body 2 on which the plurality of terminals 22 are disposed, in other words, closest to the top surface 2a of the main body 2, or may be disposed closest to the bottom surface 2b of the main body 2, in other words, may be disposed on the terminal layer 20.
As described so far, according to the present embodiment, it is possible to provide a layered chip package 1 that includes a plurality of chips 30 stacked and that is capable of achieving higher integration. The layered chip package 1 according to the present embodiment includes the main body 2 having the top surface 2a, the bottom surface 2b and the four side surfaces 2c, 2d, 2e and 2f, and wiring 3 disposed on at least one of the side surfaces of the main body 2. The main body 2 includes at least nine layer portions 10 stacked. The plurality of layer portions 10 included in the main body 2 include a plurality of pairs of layer portions 10P stacked. In the present embodiment, in particular, the plurality of layer portions 10 included in the main body 2 are all in pairs of layer portions 10P. Therefore, in the present embodiment, the main body 2 includes at least five pairs of layer portions 10P.
The plurality of layer portions 10 included in the main body 2 include a plurality of first-type layer portions 10 and at least one second-type layer portion 10. In the present embodiment, in particular, the number of the first-type layer portions 10 included in the main body 2 is eight. The plurality of pairs of layer portions 10P included in the main body 2 include a plurality of specific pairs of layer portions 10PS, each of the specific pairs of layer portions 10PS consisting of one first-type layer portion 10 and one second-type layer portion 10. In the present embodiment, in particular, the number of the specific pairs of layer portions 10PS included in the main body 2 is an even number.
Each of the first-type layer portion 10 and the second-type layer portion 10 includes a semiconductor chip 30, and an insulating portion 31 covering at least one of the four side surfaces of the semiconductor chip 30. The insulating portion 31 has at least one end face 31a located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed.
The semiconductor chip 30 included in the first-type layer portion 10 is a non-defective one whereas the semiconductor chip 30 included in the second-type layer portion 10 is a defective one. The first-type layer portion 10 further includes a plurality of electrodes 32 each of which is connected to the semiconductor chip 30 and each of which has an end face 32a located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed, whereas the second-type layer portion 10 does not include any electrode connected to the semiconductor chip 30 and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed. The end face 32a of each of the plurality of electrodes 32 is surrounded by the insulating portion 31. The wiring 3 is connected to the end faces 32a of the plurality of electrodes 32.
The method of manufacturing the layered chip package 1 according to the present embodiment includes the steps of: fabricating the layered substructure 114 by stacking two substructures 110 each of which includes a plurality of preliminary layer portions 110c aligned, each of the preliminary layer portions 110c being intended to become any one of the layer portions 10 included in the main body 2, the substructures 110 being intended to be cut later at a boundary between every adjacent two of the preliminary layer portions 110c; fabricating a pre-main-body stack 118 by using the layered substructure 114, the pre-main-body stack 118 being a stack of a predetermined two or greater number of pairs of layer portions 10P including at least one specific pair of layer portions 10PS; fabricating the main body 2 by stacking at least one additional specific pair of layer portions 10PS together with the pre-main-body stack 118, the number of the at least one additional specific pair of layer portions 10PS being equal to the number of the at least one specific pair of layer portions 10PS included in the pre-main-body stack 118; and completing the layered chip package 1 by forming the wiring 3 on the main body 2. In the present embodiment, in particular, the predetermined two or greater number mentioned above is four.
The step of fabricating the layered substructure 114 includes, as a series steps for fabricating each substructure 110, the step of fabricating a pre-substructure wafer 101 including a plurality of pre-semiconductor-chip portions 30P aligned; the step of distinguishing between a normally functioning pre-semiconductor-chip portion 30P and a malfunctioning pre-semiconductor-chip portion 30P among the plurality of pre-semiconductor-chip portions 30P included in the pre-substructure wafer 101; and the step of forming the plurality of electrodes 32 so as to be connected to the normally functioning pre-semiconductor-chip portion 30P, without forming any electrode connected to the malfunctioning pre-semiconductor-chip portion 30P and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed.
In the layered chip package 1 according to the present embodiment, the second-type layer portion 10 which includes a defective semiconductor chip 30 does not have any electrode connected to the semiconductor chip 30 and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed. Therefore, the use of the defective semiconductor chip 30 is disabled.
If a layer portion 10 including a defective semiconductor chip 30 has an electrode connected to the semiconductor chip 30 and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed, this electrode is connected to the wiring 3. In this case, the electrode connected to the defective semiconductor chip 30 generates a capacitance or inductance that is unwanted for a device implemented through the use of the layered chip package 1, such as a memory device, and/or generates a stray capacitance between itself and an electrode 32 connected to a non-defective semiconductor chip 30. This is a hindrance to increasing the operation speed of the device such as a memory device.
In contrast, according to the present embodiment, as described above, the second-type layer portion 10 which includes a defective semiconductor chip 30 does not have any electrode connected to the semiconductor chip 30 and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed. Therefore, in the layered chip package 1, the second-type layer portion 10 which includes a defective semiconductor chip 30 can be regarded as merely an insulating layer. The present embodiment thus makes it possible to disable the use of a defective semiconductor chip 30 while reducing problems attributable to wiring connected to the defective semiconductor chip 30.
In the method of manufacturing the layered chip package according to the present embodiment, the layered substructure 114 is used to form the pre-main-body stack 118 which is a stack of a predetermined two or greater number of pairs of layer portions 10P including at least one specific pair of layer portions 10PS, and the main body 2 is fabricated by stacking at least one additional specific pair of layer portions 10PS together with the pre-main-body stack 118, the number of the at least one additional specific pair of layer portions 10PS being equal to the number of the at least one specific pair of layer portions 10PS included in the pre-main-body stack 118. For example, assume that the predetermined two or greater number mentioned above is four. In this case, if a pre-main-body stack 118 that does not include any specific pair of layer portions 10PS as shown in FIG. 28 is used to produce a layered chip package 1 that does not include any defective semiconductor chip 30, then the number of the first-type layer portions 10 included in this layered chip package 1, i.e., the number of non-defective semiconductor chips 30 included in this layered chip package 1, is eight. According to the present embodiment, in the case where the pre-main-body stack 118 includes at least one specific pair of layer portions 10PS, the main body 2 is fabricated by stacking at least one additional specific pair of layer portions 10PS together with the pre-main-body stack 118, the number of the at least one additional specific pair of layer portions 10PS being equal to the number of the at least one specific pair of layer portions 10PS included in the pre-main-body stack 118. Therefore, the number of the first-type layer portions 10 included in the layered chip package 1 manufactured by this method, i.e., the number of non-defective semiconductor chips 30 included in this layered chip package 1, is eight, as in the case of a layered chip package 1 that does not include any defective semiconductor chip 30. Thus, the present embodiment make it possible to implement a layered chip package 1 that performs equally well irrespective of whether a defective semiconductor chip 30 is included or not.
Furthermore, according to the present embodiment, it is possible to make effective use of a specific pair of layer portions 10PS which includes one defective semiconductor chip 30, without discarding it. The present embodiment thus makes it possible to implement, at low cost, a layered chip package 1 that performs equally well irrespective of whether a defective semiconductor chip 30 is included or not.
According to the present embodiment, in the case where each of the plurality of semiconductor chips 30 included in the layered chip package 1 is a memory chip having an N-bit capacity (N is a natural number) and where the number of the first-type layer portions 10 included in the layered chip package 1, i.e., the number of non-defective semiconductor chips 30 included in the layered chip package 1, is eight, it is possible to implement a memory having an N-byte capacity by using this layered chip package 1. In this case, it becomes easy to recognize the capacity of the memory chip and the capacity of the memory implemented by the layered chip package 1. The same effect is obtained when the number of the first-type layer portions 10 included in the layered chip package 1 is a multiple of eight.
If a single substructure 110 is used to fabricate the pre-main-body stack 118, the substructure 110 is difficult to handle and susceptible to damage since it is thin. In contrast, according to the present embodiment, the layered substructure 114 formed by stacking two substructures 110 is used to fabricate the pre-main-body stack 118. The layered substructure 114 is greater in strength than a single substructure 110. Consequently, the present embodiment facilitates handling of the substructures 110 and prevents the substructures 110 from being damaged.
According to the present embodiment, since the pre-main-body stack 118 is fabricated by using the layered substructure 114, it is possible to reduce the number of the stacking operations in the step of fabricating the pre-main-body stack 118 in any of the examples shown in FIG. 24 to FIG. 26, compared with the case of fabricating the pre-main-body stack 118 by using a single substructure 110. For example, in the case where the pre-main-body stack 118 is fabricated by stacking four pairs of layer portions 10P as in the example shown in FIG. 24, the number of the stacking operations is smaller by half as compared with the case of fabricating the pre-main-body stack 118 by stacking eight layer portions 10 one by one. Thus, according to the present embodiment, it is possible to increase productivity of the layered chip package 1 and as a result, it is possible to reduce the cost of the layered chip package 1.
In the present embodiment, the step of fabricating the layered substructure 114 includes the steps of: fabricating the first pre-substructure wafer 101; fabricating the second pre-substructure wafer 101; fabricating the first pre-polishing substructure 109 by using the first pre-substructure wafer 101; fabricating the second pre-polishing substructure 109 by using the second pre-substructure wafer 101; bonding the first pre-polishing substructure 109 and the second pre-polishing substructure 109 to each other such that the respective first surfaces 109a of the first and second pre-polishing substructures 109 face toward each other; and polishing the respective second surfaces 109b of the first pre-polishing substructure 109 and the second pre-polishing substructure 109 in the bonded state.
Each of the first and second pre-substructure wafers 101 is fabricated through the step described with reference to FIG. 4. Each of the first and second pre-polishing substructures 109 is fabricated through the steps described with reference to FIG. 5 to FIG. 8. Through the step of polishing the respective second surfaces 109b of the first pre-polishing substructure 109 and the second pre-polishing substructure 109 in the bonded state, the layered substructure 114 is obtained. The layered substructure 114 is a stack of the first substructure 110 and the second substructure 110. The first substructure 110 is formed by thinning the first pre-polishing substructure 109 by the polishing, and the second substructure 110 is formed by thinning the second pre-polishing substructure 109 by the polishing.
If a single pre-polishing substructure 109 is polished into the substructure 110, the substructure 110 becomes difficult to handle and also becomes susceptible to damage since the substructure 110 is made thin to a thickness of, for example, 30 to 100 μm. In addition, because of a difference in thermal expansion coefficient between the semiconductor chip 30 and the insulating layer 106 in the substructure 110, the substructure 110 will become curved as it becomes thin. This also makes it difficult to handle the substructure 110 and makes the substructure 110 susceptible to damage.
According to the present embodiment, the first pre-polishing substructure 109 and the second pre-polishing substructure 109 are bonded to each other such that their respective first surfaces 109a face toward each other, and the respective second surfaces 109b of the first pre-polishing substructure 109 and the second pre-polishing substructure 109 in the bonded state are polished. This produces the layered substructure 114 which is a stack of the first substructure 110 and the second substructure 110, wherein the first substructure 110 is formed by thinning the first pre-polishing substructure 109 by the polishing, and the second substructure 110 is formed by thinning the second pre-polishing substructure 109 by the polishing. The layered substructure 114 is greater in strength than a single substructure 110. Consequently, the present embodiment facilitates handling of the first and second substructures 110 and makes the first and second substructures 110 resistant to damage.
The present embodiment provides the layered substructure 114 made up of the first and second substructures 110 that are bonded to each other such that their respective first surfaces 110a face toward each other. When a stress that acts to curve a single substructure 110 is present in each of the first and second substructures 110 by itself, the present embodiment makes it possible to cancel out such stresses of the first and second substructures 110. Consequently, it is possible to maintain the flatness of the first and second substructures 110.
According to the present embodiment, the plurality of semiconductor chips 30 stacked are electrically connected through the wiring 3 disposed on at least one of the side surfaces of the main body 2. Consequently, the present embodiment is free from the problems of the wire bonding method, that is, the problem that it is difficult to reduce the distance between electrodes so as to avoid contact between wires, and the problem that high resistances of the wires hamper a high-speed operation of a circuit.
Compared with the through electrode method, the present embodiment has the following advantages. First, the present embodiment does not require formation of through electrodes in each chip and consequently does not require a large number of steps for forming through electrodes in each chip.
According to the present embodiment, electrical connection between the plurality of semiconductor chips 30 is established through the wiring 3 disposed on at least one of the side surfaces of the main body 2. The present embodiment thus provides higher reliability of electrical connection between chips as compared with the case of using through electrodes to establish electrical connection between chips.
Furthermore, according to the present embodiment, it is possible to easily change the line width and thickness of the wiring 3. Consequently, it is possible to respond to future demands for finer wiring 3.
The through electrode method requires that the through electrodes of upper and lower chips be connected to each other by means of, for example, soldering at high temperatures. In contrast, according to the present embodiment, it is possible to form the wiring 3 at lower temperatures because the wiring 3 can be formed by plating. According to the present embodiment, it is also possible to perform bonding of the plurality of layer portions 10 at low temperatures. Consequently, it is possible to prevent the chips 30 from suffering damage from heat.
The through electrode method further requires that upper and lower chips be accurately aligned for connecting the through electrodes of the upper and lower chips to each other. In contrast, according to the present embodiment, electrical connection between the semiconductor chips 30 is performed not at an interface between every vertically adjacent two of the layer portions 10 but through the use of the wiring 3 disposed on at least one of the side surfaces of the main body 2. The accuracy required for alignment of the plurality of layer portions 10 is therefore lower than that required for alignment of a plurality of chips in the through electrode method.
The method of manufacturing the layered chip package according to the present embodiment allows a reduction in the number of steps and consequently allows a reduction in cost for the layered chip package, compared with the method of manufacturing a layered chip package disclosed in U.S. Pat. No. 5,953,588.
From the foregoing, the present embodiment makes it possible to mass-produce the layered chip package 1 at low cost in a short period of time.
Furthermore, the method of manufacturing the layered chip package 1 according to the present embodiment makes it possible to easily reduce the thicknesses of two substructures 110 that constitute the layered substructure 114 while preventing damage to the two substructures 110. The present embodiment thus allows a high-yield manufacture of the layered chip package 1 that achieves a reduction in size and a high level of integration.
In the present embodiment, the layered substructure 114 can be fabricated by a method other than the method described with reference to FIG. 5 to FIG. 21. For example, the layered substructure 114 can be fabricated by the following method. First, the first pre-polishing substructure 109 is bonded to a jig such that the first surface 109a of the first pre-polishing substructure 109 faces the jig. Next, the second surface 109b of the first pre-polishing substructure 109 bonded to the jig is polished so that the first pre-polishing substructure 109 is thinned by the polishing and thereby the first substructure 110 is formed in the state of being bonded to the jig. Next, the second pre-polishing substructure 109 is bonded to the first substructure 110 such that the first surface 109a of the second pre-polishing substructure 109 faces the polished surface of the first substructure 110. Next, the second surface 109b of the second pre-polishing substructure 109 is polished so that the second pre-polishing substructure 109 is thinned by the polishing and thereby the second substructure 110 is formed in the state of being stacked on the first substructure 110. This produces the layered substructure 114 in which the two substructures 110 are stacked.
Alternatively, the layered substructure 114 may be fabricated by bonding two substructures 110 to each other such that their respective second surfaces 110b face toward each other.
Second Embodiment
A layered chip package 1 according to a second embodiment of the invention and its manufacturing method will now be described. Reference is now made to FIG. 37 to describe the configuration of the layered chip package 1 according to the present embodiment. FIG. 37 is a perspective view of the layered chip package 1 according to the present embodiment drawn such that the respective end faces 32Aa of the plurality of first electrodes 32A are visible.
The layered chip package 1 according to the present embodiment includes, like the first embodiment, a main body 2 that is in the shape of a rectangular solid and that has a top surface 2a, a bottom surface 2b and first to fourth side surfaces 2c, 2d, 2e and 2f, and wiring 3 disposed on at least one of the side surfaces of the main body 2. In the example shown in FIG. 37, the layered chip package 1 includes first wiring 3A disposed on the first side surface 2c of the main body 2, and second wiring 3B disposed on the second side surface 2d of the main body 2. FIG. 37 shows the first side surface 2c of the main body 2 with the first wiring 3A shown with broken lines.
The main body 2 includes a plurality of layer portions 10 stacked. In the present embodiment, in particular, the main body 2 includes at least nine layer portions 10. These at least nine layer portions 10 include at least four pairs of layer portions 10P. In the present embodiment, the plurality of layer portions 10 may include one or more non-paired layer portions 10, in addition to the at least four pairs of layer portions 10P.
By way of example, FIG. 37 shows that the main body 2 includes four pairs of layer portions 11P, 12P, 13P and 14P arranged in this order from the top, and an additional first-type layer portion 16 disposed below the pair of layer portions 14P. The pairs of layer portions 11P, 12P, 13P and 14P have the same configurations as those of the first embodiment. The layer portion 16 has the same configuration as that of one of the layer portions 11A and 11B shown in FIG. 3.
The main body 2 further includes a terminal layer 20 laid on the uppermost layer portion 11A. The terminal layer 20 has the same configuration as that of the first embodiment. Every vertically adjacent two pairs of layer portions 10P are bonded to each other with an adhesive, so are the layer portion 16 and the pair of layer portions 14P to each other, and so are the layer portion 11A and the terminal layer 20 to each other.
The plurality of layer portions 10 included in the main body 2 include a plurality of first-type layer portions and at least one second-type layer portion. In the present embodiment, in particular, the number of the first-type layer portions included in the main body 2 is eight. The plurality of pairs of layer portions 10P included in the main body 2 include at least one specific pair of layer portions 10PS, the specific pair of layer portions 10PS consisting of one first-type layer portion and one second-type layer portion.
FIG. 37 shows an example in which one pair of layer portions 14P is the specific pair of layer portions 10PS. In the pair of layer portions 14P, the layer portion 14A is the first-type layer portion and the layer portion 14B is the second-type layer portion. In the example shown in FIG. 37, among the plurality of layer portions 10 included in the main body 2, eight layer portions 10 other than the layer portion 14B are the first-type layer portions. FIG. 37 shows an example in which, in the specific pair of layer portions 14P, the upper layer portion 14A is the first-type layer portion and the lower layer portion 14B is the second-type layer portion. However, in a specific pair of layer portions 10PS, the lower layer portion may be the first-type layer portion and the upper layer portion may be the second-type layer portion.
Among the at least nine layer portions 10 included in the main body 2, the additional first-type layer portion 16 is disposed farthest from the surface of the main body 2 on which the plurality of terminals 22 are disposed, or in other words, disposed closest to the bottom surface 2b of the main body 2.
Reference is now made to FIG. 38 to describe the method of manufacturing the layered chip package 1 according to the present embodiment. FIG. 38 is an illustrative view showing the step of fabricating the main body 2 in the method of manufacturing the layered chip package 1 according to the present embodiment. In the method of manufacturing the layered chip package 1 according to the present embodiment, the steps up to the step of fabricating the pre-main-body stack 118 are the same as those of the first embodiment. In the step of fabricating the main body 2 of the present embodiment, first, the number of the specific pair(s) of layer portions 10PS included in the pre-main-body stack 118 is identified from the information obtained by the wafer sort test. When the number of the specific pair(s) of layer portions 10PS included in the pre-main-body stack 118 is zero, in other words, when all of the plurality of pairs of layer portions 10P included in the pre-main-body stack 118 each consist of two first-type layer portions, the structure made up of the pre-main-body stack 118 and the terminal layer 20 bonded thereonto functions as the main body 2, as in the first embodiment. Then, the wiring 3 is formed on this main body 2 to thereby fabricate a layered chip package that does not include any defective semiconductor chip 30.
As shown in FIG. 38, when the pre-main-body stack 118 includes at least one specific pair of layer portions 10PS, the main body 2 is fabricated by stacking at least one additional first-type layer portion 10 (16) and the terminal layer 20 together with the pre-main-body stack 118, the number of the at least one additional first-type layer portion 10 being equal to the number of the at least one specific pair of layer portions 10PS included in the pre-main-body stack 118. Then, the wiring 3 is formed on the main body 2 in the same way as the first embodiment, so that the layered chip package 1 is completed. The additional first-type layer portion 10 is formed by cutting a single substructure 110.
Reference is now made to FIG. 39 and FIG. 40 to describe an example of the method of fabricating the additional first-type layer portion 10. According to this example, as shown in FIG. 39, a pre-polishing substructure 109 fabricated in the step shown in FIG. 8 is bonded to a jig 112 with an insulating adhesive such that the first surface 109a of the pre-polishing substructure 109 faces a surface of the jig 112. An insulating layer 111 formed by the adhesive covers the electrodes 32 and will become part of the insulating portion 31. It is preferred that the insulating layer 111 be transparent.
Next, the second surface 109b of the pre-polishing substructure 109 is polished. This polishing is performed until the plurality of grooves 104 become exposed. In FIG. 39 the broken line indicates the position of the surface 109b after the polishing. As a result of polishing the second surface 109b of the pre-polishing substructure 109, the pre-polishing substructure 109 is thinned by the polishing and thereby a substructure 110 is formed in the state of being bonded to the jig 112.
FIG. 40 shows the substructure 110 bonded to the jig 112. This substructure 110 has a first surface 110a corresponding to the first surface 109a of the pre-polishing substructure 109, and a second surface 110b opposite to the first surface 110a. The second surface 110b is the polished surface.
A plurality of non-paired layer portions 10 are formed by cutting the substructure 110 of FIG. 40 along the scribe lines 102A and 102B shown in FIG. 9. Among those plurality of layer portions 10, only the first-type layer portions 10 are used as the additional first-type layer portions 10.
In the case of fabricating the main body 2 by stacking two additional first-type layer portions 10 together with the pre-main-body stack 118, the two additional first-type layer portions 10 may be formed by cutting the layered substructure 114.
In the present embodiment, among the at least nine layer portions 10 included in the main body 2, one of the additional first-type layer portions 10 may be disposed closest to the top surface 2a of the main body 2 on which the plurality of terminals 22 are disposed, or in other words, may be disposed below the terminal layer 20.
In the present embodiment, like the modification example of the first embodiment shown in FIG. 36, the terminal layer 20 may be disposed closer to the bottom surface 2b of the main body 2 than are the at least nine layer portions 10 included in the main body 2. In this case, among the at least nine layer portions 10 included in the main body 2, one of the additional first-type layer portions 10 may be disposed farthest from the surface of the main body 2 on which the plurality of terminals 22 are disposed, in other words, closest to the top surface 2a of the main body 2, or may be disposed closest to the bottom surface 2b of the main body 2 on which the plurality of terminals 22 are disposed, in other words, may be disposed on the terminal layer 20.
The remainder of configuration, function and effects of the present embodiment are similar to those of the first embodiment, except differences resulting from the use of at least one additional first-type layer portion 10 in place of the at least one additional specific pair of layer portions 10PS used in the first embodiment.
Third Embodiment
A layered chip package 1 according to a third embodiment of the invention and its manufacturing method will now be described. Reference is now made to FIG. 41 to describe the configuration of the layered chip package 1 according to the present embodiment. FIG. 41 is a perspective view of the layered chip package 1 according to the present embodiment drawn such that the respective end faces 32Aa of the plurality of first electrodes 32A are visible.
The layered chip package 1 according to the present embodiment includes, like the first embodiment, a main body 2 that is in the shape of a rectangular solid and that has a top surface 2a, a bottom surface 2b and first to fourth side surfaces 2c, 2d, 2e and 2f, and wiring 3 disposed on at least one of the side surfaces of the main body 2. In the example shown in FIG. 41, the layered chip package 1 includes first wiring 3A disposed on the first side surface 2c of the main body 2, and second wiring 3B disposed on the second side surface 2d of the main body 2. FIG. 41 shows the first side surface 2c of the main body 2 with the first wiring 3A shown with broken lines.
The main body 2 includes a plurality of layer portions 10 stacked. In the present embodiment, in particular, the main body 2 includes at least nine layer portions 10. These at least nine layer portions 10 include at least four pairs of layer portions 10P. In the present embodiment, the plurality of layer portions 10 may include one or more non-paired layer portions 10, in addition to the at least four pairs of layer portions 10P.
By way of example, FIG. 41 shows that the main body 2 includes four pairs of layer portions 11P, 12P, 13P and 14P arranged in this order from the top, and an additional first-type layer portion 17 disposed on the pair of layer portions 11P. The pairs of layer portions 11P, 12P, 13P and 14P have the same configurations as those of the first embodiment. The layer portion 17 has the same configuration as that of one of the layer portions 11A and 11B shown in FIG. 3.
The main body 2 further includes a terminal layer 20 laid on the uppermost layer portion 17. The terminal layer 20 has the same configuration as that of the first embodiment. Every vertically adjacent two pairs of layer portions 10P are bonded to each other with an adhesive, so are the layer portion 17 and the pair of layer portions 11P to each other, and so are the layer portion 17 and the terminal layer 20 to each other.
The plurality of layer portions 10 included in the main body 2 include a plurality of first-type layer portions and at least one second-type layer portion. In the present embodiment, in particular, the number of the first-type layer portions included in the main body 2 is eight. The plurality of pairs of layer portions 10P included in the main body 2 include at least one specific pair of layer portions 10PS, the specific pair of layer portions 10PS consisting of one first-type layer portion and one second-type layer portion.
FIG. 41 shows an example in which one pair of layer portions 14P is the specific pair of layer portions 10PS. In the pair of layer portions 14P, the layer portion 14A is the first-type layer portion and the layer portion 14B is the second-type layer portion. In the example shown in FIG. 41, among the plurality of layer portions 10 included in the main body 2, eight layer portions 10 other than the layer portion 14B are the first-type layer portions. FIG. 41 shows an example in which, in the specific pair of layer portions 14P, the upper layer portion 14A is the first-type layer portion and the lower layer portion 14B is the second-type layer portion. However, in a specific pair of layer portions 10PS, the lower layer portion may be the first-type layer portion and the upper layer portion may be the second-type layer portion.
Among the at least nine layer portions 10 included in the main body 2, the additional first-type layer portion 17 is disposed closest to the top surface 2a of the main body 2 on which the plurality of terminals 22 are disposed, or in other words, disposed below the terminal layer 20.
Reference is now made to FIG. 42 to describe the method of manufacturing the layered chip package 1 according to the present embodiment. FIG. 42 is an illustrative view showing the step of fabricating the main body 2 in the method of manufacturing the layered chip package 1 according to the present embodiment. In the method of manufacturing the layered chip package 1 according to the present embodiment, the steps up to the step of fabricating the pre-main-body stack 118 are the same as those of the first embodiment. In the step of fabricating the main body 2 of the present embodiment, first, the number of the specific pair(s) of layer portions 10PS included in the pre-main-body stack 118 is identified from the information obtained by the wafer sort test. When the number of the specific pair(s) of layer portions 10PS included in the pre-main-body stack 118 is zero, in other words, when all of the plurality of pairs of layer portions 10P included in the pre-main-body stack 118 each consist of two first-type layer portions, the structure made up of the pre-main-body stack 118 and the terminal layer 20 bonded thereonto functions as the main body 2, as in the first embodiment. Then, the wiring 3 is formed on this main body 2 to thereby fabricate a layered chip package that does not include any defective semiconductor chip 30.
As shown in FIG. 42, when the pre-main-body stack 118 includes at least one specific pair of layer portions 10PS, the main body 2 is fabricated by stacking at least one additional first-type layer portion 10 (17) and the terminal layer 20 together with the pre-main-body stack 118, the number of the at least one additional first-type layer portion 10 being equal to the number of the at least one specific pair of layer portions 10PS included in the pre-main-body stack 118. In the present embodiment, in particular, a stack of at least one additional first-type layer portion 10 and the terminal layer 20 is stacked on the pre-main-body stack 118 to fabricate the main body 2. Thus, according to the present embodiment, the step of fabricating the main body 2 and the step of forming the plurality of terminals 22 are performed simultaneously by stacking the at least one additional first-type layer portion 10 with the plurality of terminals 22 integrated therewith as described above, together with the pre-main-body stack 118. Then, the wiring 3 is formed on the main body 2 in the same way as the first embodiment, so that the layered chip package 1 is completed.
Reference is now made to FIG. 43 to describe an example of the method of fabricating the stack of at least one additional first-type layer portion 10 and the terminal layer 20. In this example, at least one substructure 110 and the terminal wafer 120 are stacked and bonded to each other to thereby fabricate a stack of the substructure 110 and the terminal wafer 120 as shown in FIG. 43. Cutting this stack along the scribe lines 102A and 102B shown in FIG. 9 produces a plurality of stacks of at least one layer portion 10 and the terminal layer 20. Among the plurality of stacks of the at least one layer portion 10 and the terminal layer 20, one that does not include any second-type layer portion 10 is used as the stack of at least one additional first-type layer portion 10 and the terminal layer 20.
FIG. 43 shows a stack of a single substructure 110 and the terminal wafer 120. Cutting this stack produces a stack of one additional first-type layer portion 10 and the terminal layer 20. A single substructure 110 can be fabricated by the method described in the second embodiment, for example.
A stack of two or more additional first-type layer portions 10 and the terminal layer 20 can be produced by fabricating a stack of two or more substructures 110 and the terminal wafer 120 and then cutting this stack. A stack of two substructures 110 and the terminal wafer 120 may be produced by stacking the layered substructure 114 and the terminal wafer 120 together.
In the present embodiment, as in the second embodiment, the terminal layer 20 may be disposed closer to the bottom surface 2b of the main body 2 than are the plurality of layer portions 10 included in the main body 2, like the modification example of the first embodiment shown in FIG. 36. In this case, among the at least nine layer portions 10 included in the main body 2, one of the additional first-type layer portions 10 is disposed closest to the bottom surface 2b of the main body 2 on which the plurality of terminals 22 are disposed, in other words, disposed on the terminal layer 20. The remainder of configuration, function and effects of the present embodiment are similar to those of the second embodiment.
Fourth Embodiment
A method of manufacturing a layered chip package 1 according to a fourth embodiment of the invention will now be described. The method of manufacturing the layered chip package 1 according to the present embodiment is different from the method of the first embodiment only in the step of forming the frame 108. First, in the present embodiment, the photoresist layer used for forming the frame 108 is positive-working.
The exposure step of exposing the photoresist layer for forming the frame 108 of the present embodiment will now be described with reference to the flow chart of FIG. 44. In the exposure step of the present embodiment, as in the first embodiment, the photoresist layer is exposed such that a latent image corresponding to the plurality of electrodes 32 is formed on a portion of the photoresist layer corresponding to a normally functioning pre-semiconductor-chip portion 30P whereas any latent image corresponding to an electrode connected to a malfunctioning pre-semiconductor-chip portion 30P and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed is not formed on a portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion 30P. In this exposure step, first, among the plurality of the pattern projection regions corresponding to the plurality of pre-semiconductor-chip portions 30P, a pattern projection region corresponding to a first pre-semiconductor-chip portion 30P is selected to be exposed by the exposure apparatus of FIG. 14 (Step S201). Next, the control device 250 judges whether the pre-semiconductor-chip portion 30P corresponding to the selected pattern projection region is a normally functioning one or not (Step S202).
If the pre-semiconductor-chip portion 30P is judged as a normally functioning one (Y) in Step S202, the portion of the photoresist layer corresponding to the normally functioning pre-semiconductor-chip portion 30P is exposed in an electrode pattern corresponding to the plurality of electrodes 32 through a mask 201 having the electrode pattern (Step S203). Specifically, the electrode pattern of the present embodiment is configured to allow light to be applied to the area of the pattern projection region where to form the grooves 108a to later accommodate the electrodes 32 and to disallow light to be applied to the remaining area of the pattern projection region. As a result of this exposure, a latent image corresponding to the plurality of electrodes 32 is formed on the portion of the photoresist layer corresponding to the normally functioning pre-semiconductor-chip portion 30P. To be more specific, in the portion of the photoresist layer corresponding to a normally functioning pre-semiconductor-chip portion 30P, the area where to form the grooves 108a to later accommodate the electrodes 32 becomes soluble in the developing solution upon this exposure, while the remaining area remains insoluble in the developing solution.
If the pre-semiconductor-chip portion 30P is judged as a malfunctioning one (N) in Step S202, the portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion 30P is not subjected to any exposure (Step S204). As a result, any latent image corresponding to an electrode connected to the malfunctioning pre-semiconductor-chip portion 30P and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed is not formed on the portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion 30P. Specifically, the entire portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion 30P remains insoluble in the developing solution. In the case where the second-type layer portion 10 includes an electrode or wiring other than one connected to a defective semiconductor chip 30 and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed, an exposure is performed in Step S204 such that a latent image corresponding to such an electrode or wiring is formed, instead of no exposure. In this case also, any latent image corresponding to an electrode connected to the malfunctioning pre-semiconductor-chip portion 30P and having an end face located at the at least one of the side surfaces of the main body 2 on which the wiring 3 is disposed is not formed on the portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion 30P.
After the Step S203 or S204 is performed, the control device 250 judges whether the pattern projection region having undergone the Step S203 or S204 is the region corresponding to the last pre-semiconductor-chip portion 30P (Step S205). If the pattern projection region is judged as corresponding to the last pre-semiconductor-chip portion 30P (Y), the exposure step is finished. If the pattern projection region is judged as not corresponding to the last pre-semiconductor-chip portion 30P (N), a pattern projection region corresponding to a next pre-semiconductor-chip portion 30P is selected to be exposed (Step S206) and the process starting from Step S202 is repeated.
FIG. 45 is an illustrative view showing the exposure step of FIG. 44. Reference numeral 108P in FIG. 45 indicates the photoresist layer to be used for forming the frame 108. Portions (a), (b), (c) and (d) of FIG. 45 indicate regions for which Step S203 or S204 is to be performed. In the example of FIG. 45, Step S203 or S204 is performed in the order of the regions (a), (b), (c) and (d). For the regions (a), (c) and (d), the corresponding pre-semiconductor-chip portions 30P have been judged as normally functioning ones in Step S202 and consequently the portions of the photoresist layer 108P corresponding to those normally functioning pre-semiconductor-chip portions 30P are each exposed in the electrode pattern through a mask 201C having the electrode pattern. For the region (b), the corresponding pre-semiconductor-chip portion 30P has been judged as a malfunctioning one in Step S202 and consequently the portion of the photoresist layer 108P corresponding to the malfunctioning pre-semiconductor-chip portion 30P is not subjected to any exposure. Portion (e) of FIG. 45 shows the plane geometry of the latent image formed on the photoresist layer 108P by exposure.
After the exposure step described above, the photoresist layer 108P is developed with a developing solution and the frame 108 is thereby formed. The shape of the frame 108 is the same as that of the first embodiment.
The remainder of configuration, function and effects of the present embodiment are similar to those of the first to third embodiments.
Fifth Embodiment
A method of manufacturing a layered chip package 1 according to a fifth embodiment of the invention will now be described. The method of manufacturing the layered chip package 1 according to the present embodiment is different from the method of the first embodiment only in the step of forming the frame 108. First, in the present embodiment, the photoresist layer used for forming the frame 108 is negative-working.
In the present embodiment, the step of forming the frame 108 includes: a first exposure step of exposing all of the plurality of portions of the photoresist layer corresponding to the plurality of pre-semiconductor chip portions 30P, that is, all of the pattern projection regions, in the electrode pattern corresponding to the plurality of electrodes 32; a second exposure step of subjecting only a portion of the photoresist layer corresponding to a malfunctioning pre-semiconductor-chip portion 30P to an overall exposure, the second exposure step being performed before or after the first exposure step; and a step of developing the photoresist layer performed after the first and second exposure steps.
Reference is now made to FIG. 46 and FIG. 47 to describe the case of performing the second exposure step after the first exposure step. FIG. 46 is an illustrative view showing the first exposure step. FIG. 47 is an illustrative view showing the second exposure step. In FIG. 46 and FIG. 47 reference numeral 108P indicates the photoresist layer to be used for forming the frame 108.
Portions (a), (b), (c) and (d) of FIG. 46 indicate regions to undergo exposure in the electrode pattern in the first exposure step. In the first exposure step, all of the plurality of portions of the photoresist layer 108P corresponding to the plurality of pre-semiconductor chip portions 30P are exposed in the electrode pattern through the mask 201A having the electrode pattern. As a result, a latent image of the electrode pattern is formed on all of the plurality of portions of the photoresist layer 108P corresponding to the plurality of pre-semiconductor chip portions 30P. Portion (e) of FIG. 46 shows the plane geometry of the latent image formed on the photoresist layer 108P by exposure.
Regions (a), (b), (c) and (d) of FIG. 47 correspond to the regions (a), (b), (c) and (d) of FIG. 46. In the example shown in FIG. 47, the pre-semiconductor-chip portions 30P in the regions (a), (c) and (d) are normally functioning ones whereas the pre-semiconductor-chip portion 30P in the region (b) is a malfunctioning one. In the second exposure step, the portion of the photoresist layer 108P corresponding to the malfunctioning pre-semiconductor-chip portion 30P in the region (b) is subjected to an overall exposure. Portion (e) of FIG. 47 shows the plane geometry of the latent image formed on the photoresist layer 108P by exposure.
In the region (b), although the latent image is formed by the first exposure step as shown in FIG. 46, it disappears by the overall exposure performed in the second exposure step. As a result, the entire portion of the photoresist layer 108P corresponding to the malfunctioning pre-semiconductor-chip portion 30P becomes insoluble in the developing solution.
After the first and second exposure steps, the photoresist layer 108P is developed with the developing solution and the frame 108 is thereby formed. The shape of the frame 108 is the same as that of the first embodiment.
In the present embodiment, the first exposure step may be performed after the second exposure step. In this case, first, by performing the second exposure step, an entire portion of the photoresist layer 108P corresponding to a malfunctioning pre-semiconductor-chip portion 30P becomes insoluble in the developing solution. Then, by performing the first exposure step, a latent image of the electrode pattern is formed on a portion of the photoresist layer 108P corresponding to a normally functioning pre-semiconductor chip portion 30P. At this time, although the portion of the photoresist layer corresponding to the malfunctioning pre-semiconductor-chip portion 30P is also exposed, the whole of this portion has already become insoluble in the developing solution through the overall exposure. There is no difference in the resulting frame 108 between the case where the first exposure step is performed after the second exposure step and the case where the second exposure step is performed after the first exposure step.
According to the present embodiment, since there is no need to replace the mask 201 during each of the first exposure step and the second exposure step, each of the first and second exposure steps can be completed in a short period of time. In the first exposure step, in particular, since all of the pattern projection regions are to be exposed in the same electrode pattern, two or more, such as four to six, of the pattern projection regions can be simultaneously exposed using a stepper. In the first exposure step, for example, use of a contact aligner or a projection aligner in place of the stepper allows exposing all of the pattern projection regions simultaneously. Exposing a plurality of pattern projection regions simultaneously in the first exposure step as described above reduces the time required for the first exposure step. From the foregoing, compared with the first and second embodiments, the present embodiment serves to shorten the time required for the process of exposing the photoresist layer 108P for forming the frame 108, and thereby serves to increase productivity.
The remainder of configuration, function and effects of the present embodiment are similar to those of the first to third embodiments.
The present invention is not limited to the foregoing embodiments but can be carried out in various modifications. For example, the terminal layer 20 may be eliminated from the main body 2 of the layered chip package 1 and part of the wiring 3 may also function as external connecting terminals.
It is apparent that the present invention can be carried out in various forms and modifications in the light of the foregoing descriptions. Accordingly, within the scope of the following claims and equivalents thereof, the present invention can be carried out in forms other than the foregoing most preferred embodiments.

## Claims

1. A layered chip package comprising:
a main body having a top surface, a bottom surface and four side surfaces; and
wiring disposed on at least one of the four side surfaces of the main body, wherein:
the main body includes pairs of layer portions, the pairs of layer portions being stacked in a stacking direction extending between the top surface and the bottom surface, each of the pairs of layer portions consisting of two layer portions that are stacked in the stacking direction;
the pairs of layer portions include specific pairs of layer portions, each of the specific pairs of layer portions consisting of a first-type layer portion and a second-type layer portion;
the specific pairs of layer portions are provided in an even number;
each of the first-type layer portion and each of the second-type layer portion includes a semiconductor chip;
a semiconductor chip of the first-type layer portion has a first surface and a second surface that face toward opposite directions, and a plurality of chip terminals provided on the first surface of the semiconductor chip of the first-type layer portion, the first surface and the second surface of the semiconductor chip of the first-type layer portion being substantially orthogonal to the stacking direction;
a semiconductor chip of the second-type layer portion has a first surface and a second surface that face toward opposite directions, and a plurality of chip terminals provided on the first surface of the semiconductor chip of the second-type layer portion, the first surface and the second surface of the semiconductor chip of the second-type layer portion being substantially orthogonal to the stacking direction;
the semiconductor chip of the first-type layer portion is non-malfunctioning;
the first-type layer portion further includes a plurality of electrodes, each of the plurality of electrodes (1) being formed on the first surface of the semiconductor chip of the first-type layer portion, (2) having a bottom surface that is directly above the first surface of the semiconductor chip of the first-type layer portion, (3) extending along the first surface of the semiconductor chip of the first-type layer portion, and (4) connecting any one of the plurality of chip terminals of the semiconductor chip of the first-type layer portion to the wiring;
the semiconductor chip of the second-type layer portion is malfunctioning; and
the second-type layer portion does not include any electrode that extends along the first surface of the semiconductor chip of the second-type layer portion and that is connected to any one of the plurality of chip terminals of the semiconductor chip of the second-type layer portion, so that the semiconductor chip of the second-type layer portion is disabled.

2. The layered chip package according to claim 1, wherein the pairs of layer portions further include at least one pair of two first-type layer portions.

3. The layered chip package according to claim 1, wherein the first-type layer portions included in the main body are eight in number.

4. The layered chip package according to claim 1, wherein:
the semiconductor chip of the first-type layer portion and the semiconductor chip of the second-type layer portion each have four side surfaces;
each of the first-type layer portion and the second-type layer portion further includes an insulating portion covering at least one of the four side surfaces of the semiconductor chip;
the insulating portion has at least one end face located at the at least one of the four side surfaces of the main body on which the wiring is disposed; and
the plurality of electrodes have their respective end faces exposed from the insulating portion.

5. The layered chip package according to claim 1, wherein one of the specific pairs of layer portions is disposed closest to the top surface or the bottom surface of the main body among the pairs of layer portions included in the main body.

6. The layered chip package according to claim 1, further comprising package terminals disposed on one of the top surface and the bottom surface of the main body, wherein:
the wiring is connected to the package terminals; and
one of the specific pairs of layer portions is disposed farthest from the surface of the main body on which the package terminals are disposed, among the pairs of layer portions included in the main body.

7. A layered chip package comprising:
a main body having a top surface, a bottom surface and four side surfaces; and
wiring disposed on at least one of the four side surfaces of the main body, wherein:
the main body includes a layered body consisting of four pairs of layer portions, each of the four pairs of layer portions consisting of two layer portions that are stacked in a stacking direction extending between the top surface and the bottom surface;
the four pairs of layer portions include at least one specific pair of layer portions, the specific pair of layer portions consisting of one first-type layer portion and one second-type layer portion;
the main body further includes at least one additional layer portion that is stacked together with the layered body, the at least one additional layer portion being equal in number to the at least one specific pair of layer portions included in the layered body;
the first-type layer portion, the second-type layer portion, and the at least one additional layer portion each include a semiconductor chip;
a semiconductor chip of the first-type layer portion has a first surface and a second surface that face toward opposite directions, and a plurality of chip terminals provided on the first surface of the semiconductor chip of the first-type layer portion, the first surface and the second surface of the semiconductor chip of the first-type layer portion being substantially orthogonal to the stacking direction;
a semiconductor chip of the second-type layer portion has a first surface and a second surface that face toward opposite directions, and a plurality of chip terminals provided on the first surface of the semiconductor chip of the second-type layer portion, the first surface and the second surface of the semiconductor chip of the second-type layer portion being substantially orthogonal to the stacking direction;
a semiconductor chip of the at least one additional layer portion has a first surface and a second surface that face toward opposite directions, and a plurality of chip terminals provided on the first surface of the semiconductor chip of the at least one additional layer portion, the first surface and the second surface of the semiconductor chip of the at least one additional layer portion being substantially orthogonal to the stacking direction;
the semiconductor chip of the first-type layer portion and the semiconductor chip of the at least one additional layer portion are non-malfunctioning;
the first-type layer portion further includes a plurality of electrodes, each of the plurality of electrodes (1) being formed on the first surface of the semiconductor chip of the first-type layer portion, (2) having a bottom surface that is directly above the first surface of the semiconductor chip of the first-type layer portion, (3) extending along the first surface of the semiconductor chip of the first-type layer portion, and (4) connecting any one of the plurality of chip terminals of the semiconductor chip of the first-type layer portion to the wiring;
the at least one additional layer portion further includes a plurality of additional electrodes, each of the plurality of additional electrodes (1) being formed on the first surface of the semiconductor chip of the at least one additional layer portion, (2) having a bottom surface that is directly above the first surface of the semiconductor chip of the at least one additional layer portion, (3) extending along the first surface of the semiconductor chip of the at least one additional layer portion, and (4) connecting any one of the plurality of chip terminals of the semiconductor chip of the at least one additional layer portion to the wiring;
the semiconductor chip of the second-type layer portion is malfunctioning; and
the second-type layer portion does not include any electrode that extends along the first surface of the semiconductor chip of the second-type layer portion and that is connected to any one of the plurality of chip terminals of the semiconductor chip of the second-type layer portion, so that the semiconductor chip of the second-type layer portion is disabled.

8. The layered chip package according to claim 7, wherein:
the semiconductor chip of the first-type layer portion and the semiconductor chip of the second-type layer portion each have four side surfaces;
each of the first-type layer portion and the second-type layer portion further includes an insulating portion covering at least one of the four side surfaces of the semiconductor chip;
the insulating portion has at least one end face located at the at least one of the four side surfaces of the main body on which the wiring is disposed; and
the plurality of electrodes have their respective end faces exposed from the insulating portion.

9. The layered chip package according to claim 7, wherein one of the at least one additional layer portion is disposed at a position in the main body closest to the top surface or the bottom surface of the main body.

10. The layered chip package according to claim 7, further comprising package terminals disposed on one of the top surface and the bottom surface of the main body, wherein:
the wiring is connected to the package terminals; and
one of the at least one additional layer portion is disposed at a position in the main body farthest from the surface of the main body on which the package terminals are disposed.

11. The layered chip package according to claim 7, further comprising package terminals disposed on one of the top surface and the bottom surface of the main body, wherein:
the wiring is connected to the package terminals; and
one of the at least one additional layer portion is disposed at a position in the main body closest to the surface of the main body on which the package terminals are disposed.