CHIP PICK-UP HEAD, AND CHIP DETACHMENT APPARATUS AND METHOD USING THE PICK-UP HEAD

A chip pick-up head includes a collet in contact with an upper surface of a chip of a diced wafer. The chip pick-up head detaches and picks up the chip from an adhesive film. The chip pick-up head further includes a head part coupled to the collet, a vibration transfer rod coupled to the head part and configured to transfer a vibration to the head part and the collet, and a vibration generator coupled to the vibration transfer rod and configured to generate the vibration.

CROSS-REFERENCE TO RELATED APPLICATION

TECHNICAL FIELD

Embodiments of the inventive concept relate to an apparatus and method for detaching chips, and more particularly, to a chip pick-up head that picks up chips from a diced wafer, and an apparatus and method for detaching chips using the pick-up head.

DISCUSSION OF RELATED ART

Semiconductor devices may be formed by repeatedly performing a series of semiconductor processes on a silicon wafer substrate. A wafer on which semiconductor devices are formed may be individualized into a plurality of chips by a dicing process or a singulation process. Individualized chips may be mounted on a substrate such as, for example, a lead frame, a printed circuit board, or a semiconductor wafer, by a die attach process. The die attach process may include a chip pick-up process and a chip bonding process. The chip pick-up process may refer to a process of picking up and detaching chips of a diced wafer from an adhesive film by using a chip detachment apparatus. The bonding process may refer to a process of attaching the picked-up chips to a substrate.

SUMMARY

Embodiments of the inventive concept provides a chip pick-up head that stably detaches and picks up a chip from an adhesive film in a die attach process or a pick-up process, and a chip detachment apparatus and a chip detachment method using the pick-up head.

According to an embodiment of the inventive concept, a chip pick-up head includes a collet in contact with an upper surface of a chip of a diced wafer. The chip pick-up head detaches and picks up the chip from an adhesive film. The chip pick-up head further includes a head part coupled to the collet, a vibration transfer rod coupled to the head part and configured to transfer a vibration to the head part and the collet, and a vibration generator coupled to the vibration transfer rod and configured to generate the vibration.

According to an embodiment of the inventive concept, a chip detachment apparatus includes a wafer stage that supports a diced wafer attached to the adhesive film, an ejector stage positioned under the adhesive film and including a lifting block configured to push a chip to be picked up from the wafer, together with the adhesive film, and a chip pick-up head configured to detach and pick up the chip from the adhesive film by vacuum adsorption and vibration.

According to embodiment of the inventive concept, a chip detachment apparatus includes a wafer stage that supports a diced wafer attached to an adhesive film, an ejector stage positioned under the adhesive film and including a lifting block configured to push a chip to be picked up from the wafer, together with the adhesive film, and a chip pick-up head. The chip pick-up head includes a collet in contact with an upper surface of the chip, a head part coupled to the collet, and a vibration generator configured to generate a vibration and transfer the vibration to the head part and the collet.

According to an embodiment of the inventive concept, a method of detaching a chip to be picked up includes securing the chip, which is to be picked up from a diced wafer that is attached to an adhesive film, onto an ejector stage by vacuum adsorption, coupling a collet of a chip pick-up head to the chip by moving the chip pick-up head in a direction toward the chip, vibrating the chip pick-up head while lifting a lifting block of the ejector stage, and detaching and picking up the chip from the adhesive film by the chip pick-up head.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the inventive concept will be described more fully hereinafter with reference to the accompanying drawings. Like reference numerals may refer to like elements throughout the accompanying drawings.

It should be understood that descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments, unless the context clearly indicates otherwise.

It will be understood that when a component such as a film, a region, a layer, etc., is referred to as being “on”, “connected to”, “coupled to”, or “adjacent to” another component, it can be directly on, connected, coupled, or adjacent to the other component, or intervening components may be present. It will also be understood that when a component is referred to as being “between” two components, it can be the only component between the two components, or one or more intervening components may also be present. It will also be understood that when a component is referred to as “covering” another component, it can be the only component covering the other component, or one or more intervening components may also be covering the other component. Other words used to describe the relationships between components should be interpreted in a like fashion.

Herein, when two or more elements or values are described as being substantially the same as or about equal to each other, it is to be understood that the elements or values are identical to each other, the elements or values are equal to each other within a measurement error, or if measurably unequal, are close enough in value to be functionally equal to each other as would be understood by a person having ordinary skill in the art. For example, the term “about” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (e.g., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations as understood by one of the ordinary skill in the art. Further, it is to be understood that while parameters may be described herein as having “about” a certain value, according to example embodiments, the parameter may be exactly the certain value or approximately the certain value within a measurement error as would be understood by a person having ordinary skill in the art. Other uses of these terms and similar terms to describe the relationships between components should be interpreted in a like fashion.

It will be further understood that when two components or directions are described as extending substantially parallel or perpendicular to each other, the two components or directions extend exactly parallel or perpendicular to each other, or extend approximately parallel or perpendicular to each other within a measurement error as would be understood by a person having ordinary skill in the art.

FIG.1is a side view of a chip pick-up module according to an embodiment.

Referring toFIG.1, a chip pick-up head100according to an embodiment may include a collet110, a head part120, a vibration transfer rod130and a vibration generator140. The chip pick-up head100may include a device that picks up a chip22from a diced wafer20attached to an adhesive film24(seeFIG.2).

For example, according to an embodiment, the collet110is in contact with an upper surface of the chip22of the diced wafer20. The chip pick-up head100detaches and picks up the chip22from the adhesive film24. The head part120is coupled to the collet110. The vibration transfer rod130is coupled to the head part120and transfers a vibration(s) to the head part120and the collet110. The vibration generator140is coupled to the vibration transfer rod130and generates the vibration(s).

The collet110may be arranged at a lowermost portion of the chip pick-up head100. The collet110may be positioned on a lower surface of the head part120. The collet110may be detachable from the head part120. For example, the collet110may be worn or deformed during several processes of picking up chips by the chip pick-up head100. In such a case, a worn or deformed collet110may be detached from the head part120and be discarded, and a new collet110may be attached to the head part120and used.

The collet110may include a pad112and a collet body114. When picking up the chip22, a lower surface of the pad112may make contact with an upper surface of the chip22. The pad112may be formed of an elastic material such as, for example, rubber or silicone. However, the material of the pad112is not limited to such materials.

The pad112may include a plurality of micro vacuum holes. For example, the vacuum holes may be arranged in at least one row along an outer portion of the pad112. However, the arrangement position of the vacuum holes is not limited to the outer portion of the pad112. When picking up the chip22, vacuum suction may be performed on the chip22through the vacuum holes. In an embodiment, the vacuum holes of the pad112may be connected to a vacuum pump through a vacuum tube arranged in the collet body114, the head part120, the vibration transfer rod130, and the vibration generator140.

The collet body114may be coupled to the head part120, and the pad112may be positioned on a lower surface of the collet body114. A structure for attaching to or detaching the collet110from the head part120may be positioned on the collet body114. In addition, the vacuum tube may be arranged in the collet body114and be connected to the vacuum holes of the pad112.

As illustrated inFIG.1, the size of the collet body114may be larger than that of the pad112and be smaller than that of the head part120. Herein, the size of the collet body114may include an area, a width, and a diameter of the lower surface of the collet body114. However, the size of the collet body114is not limited thereto. For example, according to embodiments, the size of the collet body114may be substantially the same as that of the head part120.

The head part120may be a portion to which the collet110is coupled, and may have a size corresponding to the collet110. For example, the size of the head part120may be larger than that of the collet body114. In addition, a structure to which the collet110is detachable may be arranged on the lower surface of the head part120. As described above, the vacuum tube may be arranged in the head part120.

The vibration transfer rod130may have a cylindrical shape and may be integrally coupled to the head part120. For example, as described inFIG.1, the vibration transfer rod130may have a cylindrical shape extending in a direction substantially perpendicular to the upper surface of the head part120. However, the shape of the vibration transfer rod130is not limited to a cylinder. For example, the vibration transfer rod130may have an elliptical columnar shape or a polygonal columnar shape according to embodiments. As described above, the vacuum tube extending in a vertical direction may be arranged in the head part120.

According to embodiments, the vibration transfer rod130may be omitted. In such a case, the vibration generator140may be directly coupled to an upper portion of the head part120. In addition, the vibration generated by the vibration generator140may be directly transferred to the head part120and the collet110.

The vibration generator140may be coupled to an upper portion of the vibration transfer rod130. The vibration generator140may include a coupler142, a vibration generating unit144, and a cover146. The coupler142may be a portion to which the vibration transfer rod130is coupled. The vibration generating unit144may be firmly coupled to the vibration transfer rod130by the coupler142, and thus, the vibration generated from the vibration generating unit144may be efficiently transferred to the vibration transfer rod130. When the vibration transfer rod130is omitted, the coupler142may be coupled to the head part120.

The vibration generating unit144may be a device that electrically generates vibration. For example, the vibration generating unit144may include an actuator that generates vibration. The vibration generating unit144may include, for example, a voice coil motor, a piezo motor, an ultrasonic vacuum motor, and an eccentric type motor. However, the motor applied to the vibration generating unit144is not limited to the aforementioned motors. The vibration generating unit144may generate vibration in a frequency range of about 1 Hz to about 500 Hz. However, the frequency of the vibration generated by the vibration generating unit144is not limited to the frequency range described above.

The vibration generating unit144may generate vibration in an extension direction of the vibration transfer rod130. That is, the vibration generating unit144may generate vibration in a vertical direction substantially perpendicular to the upper surface of the head part120or a lower surface of the collet110. For example, when the vibration generating unit144includes a voice coil motor, the vibration generating unit144may have a cylindrical shape around which a coil is wound, and when electric power is applied to the coil, the vibration generating unit144may be vibrated by Lorentz force in the vertical direction.

The cover146may have a cylindrical tube shape covering the vibration generating unit144. When vibration is generated in the vibration generating unit144, the vibration generating unit144may be vibrated between the inside and outside of the cover146. That is, as illustrated by the thick double arrow inFIG.1, the vibration generating unit144may vibrate in the vertical direction in such a manner that the vibration generating unit144moves downward to come out of the cover146, and then moves upward again to enter the inside of the cover146.

When vibration is generated in the vibration generating unit144, the vibration is transmitted to the vibration transfer rod130through the coupler142, and the vibration is then transferred to the head part120and the collet110through the vibration transfer rod130. As a result, the head part120and the collet110may be vibrated. For example, the head part120and the collet110may be vibrated in one body in a vertical direction substantially perpendicular to the upper surface of the head part120or the lower surface of the collet110.

In addition, the frequency of the vibration of the head part120and the collet110may be substantially the same as the frequency of the vibration generated by the vibration generating unit144. For example, the vibration generating unit144may generate vibration in a frequency range of about 1 Hz to about 500 Hz, and as a result, the head part120and the collet110may vibrate at a frequency of about 1 Hz to about 500 Hz according to the vibration of the vibration generating unit144.

The chip pick-up head100according to an embodiment may include the vibration generating unit144, and the head part120and the collet110may be vibrated in the vertical direction by the vibration generated from the vibration generating unit144. Accordingly, in the process of detaching the chip22from the adhesive film24and picking up the chip, the chip pick-up head100of an embodiment may reduce stresses applied to the chip22and minimize or reduce cracks in the chip22by vibrating the head part120and the collet110in the vertical direction by the vibration generating unit144. As a result, the chip pick-up head100of an embodiment stably detaches and picks up the chip22from the adhesive film24, and thus, the reliability of the chip22and the reliability of the semiconductor package including the chip22may be increased.

FIG.2is a conceptual view schematically illustrating a chip detachment apparatus including a chip pick-up module, according to an embodiment.

InFIG.2, the chip detachment apparatus is described in detail together with reference toFIG.1. For convenience of explanation, a further description of components and technical aspects previously described with reference toFIG.1are only briefly described or omitted.

Referring toFIG.2, the chip detachment apparatus1000according to an embodiment may perform a die attach process together with a chip bonding head500. The die attach process may include a chip pick-up process and a chip bonding process. That is, the die attach process may be a single process in which the chip pick-up process for picking up the chip22from the diced wafer20and the chip bonding process for bonding the chip22onto a substrate700, such as, for example, a lead frame, a printed circuit board, a semiconductor wafer, etc., are sequentially performed. The chip detachment apparatus1000including the chip pick-up head100may be used in the chip pick-up process. In addition, the chip bonding head500may be used in the chip bonding process.

FIG.2schematically illustrates the entire chip attach process according to an embodiment. Accordingly, the chip detachment apparatus1000is illustrated inFIG.2together with the chip bonding head500. For example, as shown by a dotted line between the chip detachment apparatus1000and the substrate700, the chip bonding head500may receive the chip22from the chip pick-up head100and bond the chip22onto the substrate700. When receiving the chip22by the chip bonding head500, the chip pick-up head100may be turned up in such a manner that the chip22faces upward, and the chip bonding head500may adsorb the chip22by a vacuum pressure applied through a collet510inFIG.5D. In such a case, the vacuum adsorption may be released in the chip pick-up head100. The substrate700may be positioned on the substrate stage600.

The chip detachment apparatus1000according to an embodiment may include the chip pick-up head100, an ejector stage200, and a wafer stage300. The chip pick-up head100is the same as described in the description ofFIG.1.

The ejector stage200may be positioned below the adhesive film24. For example, the ejector stage200may be positioned below the adhesive film24where the chip22to be picked up is located. The ejector stage200may include an ejector or a lifting block220(seeFIGS.3A and3B). When detaching and picking up the chips22, the ejector stage200may push the picked-up chips22together with the adhesive film24upward by using the lifting block220. The structure of the ejector stage200is described in further detail below with reference toFIGS.3A and3B.

The wafer stage300may support a wafer20. The wafer20may include multiple chips22detached by a dicing process. The chips22may be attached to the adhesive film24. That is, the chips22may be maintained in the shape of the wafer20by being attached to the adhesive film24, although the chips22are detached from each other on the adhesive film24. The adhesive film24may be, for example, a dicing tape that is used in a dicing process for dicing the wafer20. For example, the front surfaces of the chips22may face upward, and the rear surfaces of the chips22may be attached onto the adhesive film24.

The adhesive film24may be installed on a circular ring-shaped mount frame included in the wafer stage300. In addition, a support ring for supporting the adhesive film24may be positioned on the wafer stage300. For example, the support ring may support the adhesive film24between the chips22and the mount frame. A plurality of clamps holding and fixing the mount frame may be arranged on the wafer stage300. The clamps may be moved downward by the clamp driver. The adhesive film24may be expanded by the movement of the clamps, and thus, the chips22may be efficiently picked up by the chip pick-up head100.

According to embodiments, the chip detachment apparatus1000may include a head driver that drives the chip pick-up head100and an ejector driver that drives the ejector stage200. The head driver may include a head horizontal driver that moves the chip pick-up head100in a first direction (X direction) and a second direction (Y direction) on a horizontal plane, and a head vertical driver that moves the chip pick-up head100in a third direction (Z direction) substantially perpendicular to the horizontal plane. In addition, the ejector driver may include an ejector horizontal driver that moves the ejector stage200in the first direction (X direction) and the second direction (Y direction) on the horizontal plane, and an ejector vertical driver that moves the ejector stage200in the third direction (Z direction) substantially perpendicular to the horizontal plane.

According to embodiments, the chip detachment apparatus1000may include a sensor that detects whether the chip pick-up head100makes contact with the chip22. In addition, the chip detachment apparatus1000may include a head turn driver that turns the chip pick-up head100over in such a manner that the chip22picked up by the chip pick-up head100is turned over and the rear surface of the chip22faces upward.

In the chip detachment apparatus1000of an embodiment, the chip pick-up head100may include the vibration generator140. Thus, the die attach process or the chip pick-up process may be performed in a state that the vibration is applied to the head part120and the collet110by the vibration generator140. Therefore, the stress to the chip22may be reduced, and the occurrence of a crack may be minimized or reduced in the chip22. As a result, the chip detachment apparatus1000of an embodiment may detach and pick up the chip22from the adhesive film24with high stability. In addition, the chip bonding head500may receive the chip22from the chip pick-up head100and may bond and mount the chip22on the substrate700. Accordingly, the reliability of the chip22and the reliability of a semiconductor package or an electronic product including the chip22may be increased.

According to an embodiment, the wafer stage300supports a diced wafer20attached to the adhesive film24. The ejector stage200is positioned under the adhesive film24and includes the lifting block220, which is configured to push the chip22to be picked up from the wafer20together with the adhesive film24. The chip pick-up head100is configured to detach and pick up the chip22from the adhesive film24by vacuum adsorption and vibration.

FIGS.3A and3Bare a perspective view and cross-sectional view, respectively, of the ejector stage in the chip detachment apparatus ofFIG.2.

The ejector stage is described with reference toFIGS.3A and3Btogether withFIG.2. For convenience of explanation, a further description of components and technical aspects previously described with reference toFIGS.1and2are briefly given or omitted.

Referring toFIGS.3A and3B, in the chip detachment apparatus1000according to an embodiment, the ejector stage200may include a base block210and the lifting block220. In addition, a penetrating hole Hth may be provided in a central portion of the ejector stage200. The ejector stage200may perform the vacuum adsorption and air blowing on the chip22to be picked up and the adhesive film24to which the chip22is located by using the penetrating hole Hth. As illustrated inFIG.3A, a horizontal cross section of the penetrating hole Hth may have a quadrangular shape. However, the shape of the horizontal cross section of the penetrating hole Hth is not limited thereto. For example, the horizontal cross section of the penetrating hole Hth may be in the shape of a circle, an ellipse, or a polygon other than the quadrangle.

The lifting block220may also be referred to as an ejector. The lifting block220may have a shape surrounding the penetrating hole Hth. For example, the horizontal cross section of the lifting block220may have a quadrangular ring shape corresponding to the shape of the penetrating hole Hth. However, when the shape of the horizontal cross section of the penetrating hole Hth is changed, the shape of the horizontal cross section of the lifting block220may also be changed according to the changed shape of the horizontal cross section of the penetrating hole Hth. For example, when the horizontal cross section of the penetrating hole Hth has a circular shape, the horizontal cross section of the lifting block220may have a circular ring shape.

The lifting block220may include a first block222and a second block224. The first block222may have a rectangular ring shape surrounding the penetrating hole Hth. In addition, the second block224may have a rectangular ring shape surrounding the first block222. A base block210may be positioned outside the second block224.

The ejector stage200may be moved by an ejector driver. For example, the ejector stage200may be moved on a horizontal plane by an ejector driver, to thereby move to a position under the chip22to be picked up. In addition, the lifting block220of the ejector stage200may move in a vertical direction substantially perpendicular to the horizontal plane by the ejector driver.

For example, referring to the movement of the ejector stage200in the vertical direction, when performing the detachment and pick-up process for the chip22to be picked up, the ejector stage200may move to the position under the chip22to be picked up. Thereafter, the entire lifting block220of the ejector stage200, that is, the first block222and the second block224, may be lifted from the base height H0, which is the height of an upper surface of the base block210, to the first height H1. Then, the first block222may be lifted from the first height H1to the second height H2.

The lifting of the lifting block220from the base height H0to the first height H1may be performed in a quasi-linear form. In addition, the lifting of the first block222from the first height H1to the second height H2may be continuously performed in a quasi-linear form. Herein, the quasi-linear form indicates that a graph of height over time is shown in a linear form with a regular ripple. An example of a regular ripple is shown inFIG.7B, and refers to a slight, repeated variation occurring in an otherwise linear form. In addition, the term ‘continuous’ indicates that the lifting does not stop at the first height H1and continues to lift. Accordingly, the first block222may be continuously lifted from the base height H0to the second height H2in the quasi-linear form. For example, the ripple may be caused by the vibration of the chip pick-up head100and the resulting vibration of the lifting block220.

After the chip pick-up head100detaches and picks up the chip22from the adhesive film24, the lifting block220may move down to the base height H0by the reverse process. That is, the first block222may move down from the second height H2to the first height H1, and the entire lifting block220may move down to the base height H0from the first height H1. The moving down of the lifting block220may also be continuously performed in a linear form. However, the moving down of the lifting block220is not limited to the linear and continuous progress described above. The movement of the ejector stage200in the vertical direction is described in more detail below with reference to the graphs inFIGS.6A to7B.

FIG.4is a flowchart schematically illustrating a method of detaching a chip by using the chip pick-up module, according to an embodiment.

FIGS.5A to5Dare conceptual views illustrating each operation of the method of detaching a chip inFIG.4, according to an embodiment.

The method of detaching the chip is described with reference toFIGS.4to5Dtogether withFIG.3. For convenience of explanation, a further description of components and technical aspects previously described with reference toFIGS.1to3are only briefly described or omitted.

Referring toFIG.4, in a method of detaching a chip by using the chip pick-up module of an embodiment (hereinafter, referred to as the ‘chip detachment method’), vacuum adsorption may be firstly performed on the chip22to be picked up by the ejector stage200(S110). The vacuum adsorption may be performed through the penetrating hole Hth of the ejector stage200. For example, the vacuum adsorption is not performed directly on the chip22, but rather, may be performed on a corresponding portion of the adhesive film24on which the chip22is positioned.

Referring toFIGS.4and5A, thereafter, the chip pick-up head100may move down, and the collet110of the chip pick-up head100may be coupled to the chip22(S130). In addition, the collet110performs vacuum adsorption on the chip22through the vacuum hole. Accordingly, the chip22may be adsorbed to the collet110by vacuum pressure. For example, inFIGS.5A to5C, for convenience of illustration, the lifting block220is not shown as the detached first block222and second block224, and the first block222and second block224are integrally shown as the lifting block220. In addition, inFIGS.5B and5C, for convenience of illustration, the lifting block220is shown to perform just one lifting.

Referring toFIGS.4and5B, after the collet110is coupled to the chip22, the lifting block220of the ejector stage200may lift upwards, and the chip pick-up head100may vibrate (S150). The lifting block220may lift in a direction substantially perpendicular to the top surface of the chip22, that is, in a third direction (Z direction). The chip pick-up head100may also vibrate in the third direction (Z direction). In addition, the head part120and the collet110may be vibrated in the third direction (Z direction) due to the vibration of the chip pick-up head100in the third direction (Z direction).

The chip pick-up head100may be vibrated while increasing in height in the third direction (Z direction). Accordingly, the head part120and the collet110may also be vibrated while increasing in height in the third direction (Z direction). In addition, the lifting block220may be vibrated while increasing in height in the third direction (Z direction) according to the heights of the head part120and the collet110.

For example, in the chip detachment method of an embodiment, the height of the head part120and the collet110may increase in the third direction (Z direction) in repeating the lifting and moving down of the head part120and the collet110. For example, according to an embodiment, the height of the lower surface of the collet110is changed as follows: about 0 μm→about 60 μm→about 40 μm→about 100 μm→about 80 μm→, . . . →about 540 μm→about 600 μm, so that the height of the lower surface of the collet110increases in repeating the lifting and moving down of the collet110. Depending on the size of the vibration, the height of the lifting and moving down may be variously changed.

As the chip22is adsorbed onto the collet110by the vacuum pressure and the chip22, and the adhesive film24are also adsorbed onto the ejector stage200by the vacuum pressure, the lifting block220may be vibrated and lifted corresponding to the height of the collet110. In addition, as described above with reference to the collet110, the height of the upper surface of the lifting block220may also increase in repeating the lifting and moving down. The height increase of the head part120and the collet110in repeating the lifting and moving down and the height increase of the lifting block220in repeating the lifting and moving down are described in more detail below with reference toFIGS.7A and7B.

Referring toFIGS.4and5C, thereafter, the chip pick-up head100may detach and pick up the chip22from the adhesive film24(S170). For example, the chip pick-up head100may continue to lift, and accordingly, the heights of the collet110and the chip22may continue to increase. In contrast, according to embodiments, the lifting block220is not lifted over a preset maximum height. Accordingly, as indicated by the arrows inFIG.5C, the chip22may be detached from the adhesive film24and picked up by the chip pick-up head100.

After the chip pick-up head100picks up the chips22, the lifting block220of the ejector stage200may move down to its original position. For example, the lifting block220may linearly and continuously move down to the position of the base block210. After moving down the lifting block220, the ejector stage200may move to another position under the chip22to be picked up next.

Referring toFIG.5D, after picking up the chip22, the chip pick-up head100may be turned over in such a manner that the chip22faces upwards, as shown inFIG.2. In addition, the chip bonding head500may receive the chip22from the chip pick-up head100. For example, the chip bonding head500may include a head part520and a collet510. The collet510may include a plurality of fine vacuum holes. Accordingly, the vacuum pressure may be applied to the chip22through the vacuum holes, and the chip22may be adsorbed onto the collet510by the vacuum pressure. When the chip22is transferred from the chip pick-up head100to the chip bonding head500, vacuum adsorption is performed on the collet510of the chip bonding head500, and vacuum adsorption of the collet110of the chip pick-up head100may be released.

The chip bonding head500may bond the chip22onto a substrate700such as, for example, a lead frame, a printed circuit board, or a semiconductor wafer. In addition, the chip bonding head500may bond the chip22onto another chip50as shown inFIG.5D. The chip22and the other chip50may be the same type of chip or different types of chip. Bonding of the chip22to the substrate700or another chip50may be performed by a die attach film (DAF)21attached to a lower surface of the chip22.

In the chip detachment method of an embodiment, the chip22detached and picked up by the chip detachment apparatus1000may include a memory chip and a logic chip. The memory chip may include a plurality of memory devices, such as, for example, dynamic random access memory (DRAM) devices, static random access memory (SRAM) devices, flash memory devices, electrically erasable and programmable read-only memory (EEPROM) devices, phase-change random access memory (PRAM) devices, magnetic random access memory (MRAM) devices, and resistive random access memory (RRAM) devices. In addition, the logic chip may include a plurality of logic devices, such as, for example, AND devices, NAND devices, OR devices, NOR devices, exclusive OR (XOR) devices, exclusive NOR (XNOR) devices, inverter (INV) devices, adder (ADD) devices, delay (DLY) devices, multiplexer (MXT/MXIT) devices, OAI (OR/AND/INVERTER) devices, AO (AND/OR) devices, AOI (AND/OR/INVERTER) devices, D flip-flop devices, reset flip-flop devices, master-slaver flip-flop devices, latch devices, counter devices, and buffer devices. In addition, the logic chip may include, for example, a central processing unit (CPU), a micro-processor unit (MPU), a graphic processing unit (GPU), and an application processor (AP) chip.

The chip bonding process may be performed by the chip bonding head500in such a manner that the chip22is bonded to the substrate700or another chip50, to thereby complete the die attach process of the chip22.

FIGS.6A and6Bare respectively a conceptual view and a corresponding graph of a chip detachment method using a chip detachment apparatus of a comparative example.

FIG.6Ashows sequential processes of a method of detaching and picking up a chip22in the chip detachment apparatus (Com.) of the comparative example.

FIG.6Bis a graph showing the heights of the chip pick-up head and the ejector and on/off of vacuum and air blow (e.g., blowing air on the chip) for each time interval according to each process of the method of detaching and picking up a chip shown inFIG.6A.

In the graph ofFIG.6B, the x-axis represents time in a unit of milliseconds (ms), and the y-axis represents height in a unit of μm. In addition, the y-axis indicates an on and off state of the vacuum and the air blow in the case of the vacuum and the air blow.

Referring toFIGS.6A and6B, in a method of detaching and picking up a chip by using the chip detachment apparatus of a comparative example (hereinafter referred to as the ‘comparative chip detachment method’), a chip22to be picked up is adsorbed onto the ejector stage ES by the vacuum pressure in operation {circle around (1)}. In operation {circle around (1)} ofFIG.6A, an arrow pointing downward indicates the adsorption by the vacuum pressure (referred to as vacuum adsorption). The vacuum adsorption may be performed on the chip22and the portion of the adhesive film24on which the chip22is positioned. As shown in the graph ofFIG.6B, the vacuum pressure is applied to the chip22and the vacuum is turned on at a start point of operation {circle around (1)}, so that the vacuum adsorption is performed by the ejector stage ES.

In the beginning of operation {circle around (1)}, the chip pick-up head10may be positioned apart from the chip22by a certain distance. In addition, the ejector30or the lifting block of the ejector stage ES may be positioned at the same height as the base block31.

Next, in operation {circle around (2)}, the chip pick-up head10moves downwards. As the chip pick-up head10moves downward, a lower surface of the collet of the chip pick-up head10comes closer to the chip22. In operation {circle around (2)}, as the vacuum is still maintained as the on state, the vacuum adsorption by the ejector stage ES is also kept on. In operation {circle around (2)}, the ejector30is still positioned at the same height as the base block31.

In operation {circle around (3)}, the ejector30is lifted to the first height H1. The first height H1may be, for example, about 300 μm. However, the first height H1is not limited to about 300 μm. Herein, the first height H1may be a height in a vertical direction from an upper surface of the base block31.

The ejector30includes a first block32and a second block34, and in operation {circle around (3)}, the entire ejector30, that is, both of the first block32and the second block34, is linearly lifted to the first height H1. In operation {circle around (3)}, the vacuum is still maintained as the on state, and thus, the vacuum adsorption by the ejector stage ES is continuously maintained.

In operation {circle around (4)}, the vacuum is turned off and the air blow is turned on. Air is supplied toward the chip22as the air blow indicated as an arrow pointing upward in operation {circle around (4)} inFIG.6A. In addition, the graph inFIG.6Bindicates that the vacuum is turned off and the air blow is turned on at the beginning of operation {circle around (4)}. At the beginning of operation {circle around (4)}, the first block32of the ejector30starts to lift.

In operation {circle around (5)}, the first block32of the ejector30is lifted to the second height H2. The second height H2may be, for example, about 600 μm. However, the second height H2is not limited to about 600 μm. As shown in the graph ofFIG.6B, the lift of the first block32in operation {circle around (5)} starts from the beginning of operation {circle around (4)}.

As the first block32of the ejector30is lifted to the second height H2, the chip22is lifted to such a height that the chip22makes close contact with an upper surface of the collet of the chip pick-up head. Then, the vacuum adsorption is performed by the collet.

Thereafter, the ejector30moves downwards and the chip22is detached from the adhesive film24, and accordingly, the chip22is picked up by the chip pick-up head10. As shown in the graph ofFIG.6B, the air blow is turned off when the ejector30moves downward.

Thereafter, the lifting of the chip pick-up head10, the turning over of the chip pick-up head10, the transfer of the chip22to the chip bonding head, and the bonding of the chip22to a substrate or another chip by the chip bonding head are sequentially performed.

The chip detachment method of the comparative example is performed by five operations as described above. According to the chip detachment method of this comparative example, a large stress is applied to the chip22, and thus, cracks are likely to occur in the chip22due to the large stress, as is described in the descriptions with reference toFIGS.8A to10B. As a result, the reliability of the chip22may be reduced, and a defect or a decrease in reliability may occur in a semiconductor package or electronic product including the chip22.

FIGS.7A and7Bare a flowchart showing the processes of the chip detachment method inFIG.4in more detail, and a graph corresponding to the processes of the chip detachment method inFIG.4, respectively.

In the graph ofFIG.7B, the x-axis represents time in a unit of milliseconds (ms), and the y-axis represents height in a unit of μm. In addition, the y-axis indicates an on or off state of the vacuum and the air blow in the case of the vacuum and the air blow. The chip detachment method inFIG.4is described with reference toFIGS.7A and7Btogether withFIGS.3A,3B and5A to5D. For convenience of explanation, a further description of components and technical aspects previously described with reference toFIGS.1to5Dare only briefly given or omitted.

Referring toFIGS.7A and7B, in the chip detachment method of an embodiment, the chip22to be picked up may be adsorbed onto the ejector stage200by the vacuum pressure in operation {circle around (a)}. Operation {circle around (a)} may correspond to an operation of performing the vacuum adsorption S110inFIG.7A. In addition, as shown in the graph ofFIG.7B, the vacuum may be turned on at the beginning of operation {circle around (a)}. The chip pick-up head100may maintain a certain distance from the chip22at an initial point of operation {circle around (a)}. In addition, the lifting block220of the ejector stage200may be positioned at the same height as the base block210. In the graph ofFIG.6B, the lifting block220may indicate the ejector.

Next, in operation {circle around (b)}, the chip pick-up head100may move downwards, and the collet110of the chip pick-up head100may come into close contact with the upper surface of the chip22. In addition, the vacuum adsorption may be performed in the collet110, and the chip22may be adsorbed to the collet110by the vacuum pressure. Operation {circle around (b)} corresponds to an operation S130in which the collet110is coupled to the chip inFIG.7A, as is illustrated inFIG.5A.

In operation {circle around (b)}, the vacuum is maintained on, and thus, the vacuum adsorption by the ejector stage200may be maintained. In addition, in operation {circle around (b)}, the lifting block220may still be positioned at the same height as the base block210.

In operation {circle around (c)}, the chip pick-up head100may be lifted with vibrating, and the lifting block220of the ejector stage200may also be lifted with vibrating. Operation {circle around (c)} corresponds to operation S150inFIG.7Ain which the chip pick-up head100vibrates, as is illustrated inFIG.5B.

As shown in the graph ofFIG.7B, in operation {circle around (c)}, as the vacuum is still maintained on, the vacuum adsorption by the ejector stage200may be maintained. In addition, the lifting block220may be continuously lifted from the height of the base block210to the second height H2in a quasi-linear form. The second height H2may be, for example, about 600 μm. However, the second height H2is not limited to about 600 μm. Herein, the quasi-linear form indicates that a graph of height over time is shown in a linear form with a regular ripple, as shown in the graph inFIG.7B. Herein, the ripple is generated by the vibrations, as described above.

Based on the structure of the lifting block220, the lifting block220may be lifted to a middle height, for example, the first height H1inFIG.6B, in the quasi-linear form integrally with the first block222and the second block224, and then, the first block222may be lifted to the second height H2from the first height H1in the quasi-linear form.

InFIG.7A, the height of the lifting block220may be exemplarily changed as follows: about 0 μm→about 50 μm→about 30 μm→about 80 μm→about 60 μm→, . . . →about 550 μm→about 600 μm. Herein, about 50 μm, about 80 μm, about 600 μm, etc. may be heights when the lifting block220is lifted, and about 30 μm, about 60 μm, and about 550 μm may be heights when the lifting block220moves down (or descends). That is, the lifting block220may be lifted by a unit of about 50 μm, and move down by a unit of about 20 μm. This may be the result of the lifting block220being lifted at a constant speed. The lifting heights and the descent heights of the lifting block220with vibration are not be limited to the above-mentioned values and may be varied according to embodiments.

In operation {circle around (d)}, the chip pick-up head100continues to rise, but the vibration of the chip pick-up head100is stopped. In addition, the lifting of the lifting block220is stopped. Thereafter, as the chip pick-up head100moves upward and the lifting block220moves downward, the chip22is detached from the adhesive film24, and accordingly, the chip22may be picked up by the chip pick-up head100.

Operation {circle around (d)} corresponds to operation S170inFIG.7Ain which the chip22is detached and picked up, as is illustrated inFIG.5C. As shown in the graph ofFIG.7B, in operation {circle around (d)}, the vacuum may be turned off and the air blow may be turned on. The air blow may be turned off at a part where the lifting block220moves down. For example, the detachment of the chip22from the adhesive film24may be performed in a section in which the air blow is on. However, according to embodiments, the chip22may be detached from the adhesive film24after the air blow is turned off.

Thereafter, the lifting of the chip pick-up head100, the turning over of the chip pick-up head100, the transfer of the chip22to the chip bonding head500, and the bonding of the chip22to the substrate700or another chip50by the chip bonding head500may be sequentially performed.

FIGS.8A and8Bare simulation pictures showing stress applied to chips in performing the chip detachment method by the chip detachment apparatus of the comparative example, and by the chip detachment apparatus according to an embodiment ofFIG.1in which the stresses are measured just before the chip22is detached from the adhesive film24, respectively.

Referring toFIGS.8A and8B, high stress Scom. occurs in a portion of the chip22corresponding to the first block222of the lifting block220in the chip detachment method by the chip detachment apparatus of the comparative example, as shown inFIG.8A. On the contrary, relatively low stress Sp occurs in a portion of the chip corresponding to the first block222of the lifting block220in the chip detachment method by the chip detachment apparatus of an embodiment, as shown inFIG.8B.

For example,FIGS.8A and8Bare pictures obtained by performing a black-and-white process to photographs in which the stresses are shown in colors in such a way that the stress increases as a red color is reached and decreases as a blue color is reached. When the color is processed to black-and-white, the red color and the blue color may be changed to black, and an intermediate color, such as a yellow color, may be changed to white. InFIG.8A, the black of the stress Scom. actually corresponds to the red color and shows that the stress is high. On the other hand, inFIG.8B, the gray color of the stress Sp corresponds to a degree of an orange color, showing that the stress is relatively low.

FIGS.9A and9Bare tables and graphs showing non-separation ratios of chips in a comparative evaluation of the chip detachment method by the chip detachment apparatus of the comparative example, and the chip detachment method by the chip detachment apparatus according to an embodiment ofFIG.1, respectively. Herein, the non-separation indicates that the adhesive film24is not fully removed from the chip22. In the graph ofFIG.9B, the x-axis represents the type of experiment, and the y-axis represents the non-separation ratio.

Referring toFIGS.9A and9B, and more particularly, to the contents of the table inFIG.9A, Exp1and Exp2correspond to the chip detachment method of comparative examples, and the ejector time of Exp1is set to be different from that of Exp2. For example, the ejector's descending time of Exp1is set to be about 240 ms, and the ejector's descending time of Exp2is set to be about 150 ms. Exp3corresponds to the chip detachment method of an embodiment, and the ejector time of Exp3is set to be about 150 ms identical to that of Exp2. The heights of the ejectors in Exp1, Exp2and Exp3are set identically to be about 250 μm. In addition, the evaluation was performed on a chip having a thickness of about 60 μm and a chip having a thickness of about 35 μm, and the evaluation was repeated on two hundred samples for each chip.

As shown in the table ofFIG.9A, in the chip having a thickness of about 60 μm, the numbers of undetached chips in Exp1and Exp2were 29 and 36, respectively, and the non-separation ratio of Exp1and Exp2were 15% and 18%, respectively. On the contrary, the number of undetached chips in Exp3was 21, and the non-separation ratio of Exp3was 11%. On the other hand, in the chip having a thickness of about 35 μm, the numbers of undetached chips in Exp1and Exp2were 88 and 84, respectively, and the non-separation ratio of Exp1and Exp2were 44% and 42%, respectively. On the contrary, the number of undetached chips in Exp3was 22, and the non-separation ratio of Exp3was 11%. Accordingly, the comparative evaluation confirms that the number of undetached chips and the non-separation ratio are sufficiently smaller in the chip detachment method of an embodiment than in the chip detachment method of the two comparative examples.

For example, the smaller the thickness of the chip22is, the more flexible the chip22is, and thus, the higher the non-separation ratio of the chip is. Accordingly, in the case of Exp1and Exp2, the non-separation ratio may greatly increase in the chip22having a thickness of about 35 1.™ compared to the chip22having a thickness of about 60 μm. In contrast, in the chip detachment method of an embodiment, the comparative evaluation confirms that the non-separation ratio is similarly low in the chip22having a thickness of about 60 μm and the chip having a thickness of about 35 μm.

FIGS.10A and10Bare a table and a graph showing crack generation ratios of chips in a comparative evaluation of the chip detachment method by the chip detachment apparatus of the comparative example, and the chip detachment method by the chip detachment apparatus according to an embodiment ofFIG.1, respectively. In the graph ofFIG.10B, the x-axis represents the type of experiment, and the y-axis represents the crack generation ratio of a chip.

Referring toFIGS.10A and10B, and more particularly, to the contents of the table inFIG.10A, Exp1and Exp2correspond to the chip detachment method of comparative examples, and the ejector time of Exp1is set to be different from that of Exp2. For example, the ejector's descending time of Exp1is set to be about 240 ms, and the ejector's descending time of Exp2is set to be about 150 ms. Exp3corresponds to the chip detachment method of an embodiment, and the ejector time of Exp3is set to be about 150 ms identical to that of Exp2. The heights of the ejectors in Exp1, Exp2and Exp3are set identically to be about 600 μm. In addition, the evaluation was performed on a chip having a thickness of about 60 μm and a chip having a thickness of about 35 μm, and the evaluation was repeated on two hundred samples for each chip.

As shown in the table ofFIG.10A, in the chip having a thickness of about 60 μm, the numbers of crack chips in Exp1and Exp2were identically21, and the crack generation ratios of Exp1and Exp2were identically 11%. On the contrary, the number of crack chips in Exp3was 7, and the crack generation ratio of Exp3was 4%. On the other hand, in a chip having a thickness of about 35 μm, the numbers of crack chips of Exp1and Exp2area1and3, respectively, and the crack generation ratios of Exp1and Exp2were 1% and 2%, respectively. In contrast, the number of crack chips in Exp3was 0, and the crack generation ratio of Exp3was 0%. Accordingly, the comparative evaluation confirms that the number of crack chips and the crack generation ratio are sufficiently smaller in the chip detachment method of an embodiment than in the chip detachment method of the two comparative examples.

For example, the smaller the thickness of the chip22is, the more flexible the chip22is, and thus, the lower the crack generation ratio of the chip is. Accordingly, in the case of Exp1and Exp2, the crack generation ratio may greatly decrease in the chip22having a thickness of about 35 μm compared to the chip22having a thickness of about 60 μm. In contrast, in the chip detachment method of an embodiment, the comparative evaluation confirms that the crack generation ratio of the chip having a thickness of about 60 μm is relatively low at about 4%, and the crack generation ratio of the chip having a thickness of 35 μm is 0% without any cracks in the chip.

While the inventive concept has been particularly shown and described with reference to embodiments thereof, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope of the inventive concept as defined by the following claims.