Test apparatus for semiconductor package

The present disclosure discloses a test apparatus for testing a package-on-package (POP) type semiconductor package includes a lower socket mounted to a tester board providing a test signal, and provided with a plurality of socket pins connected to a lower terminal of a lower package to electrically connect the lower package and the tester board to each other; a pusher to which an upper package is coupled, the pusher having a pusher body which may be moved to approach the lower socket or to be moved away from the lower socket; and an upper socket coupled to the pusher body, and provided with an insulating pad formed of a nonelastic insulating material and a plurality of electrically-conductive parts supported on the insulating pad, the electrically-conductive part being formed of an elastic insulating material containing a plurality of electrically-conductive particles.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Korean Patent Application No. 10-2020-0036730, filed on Mar. 26, 2020, and priority of Korean Patent Application No. 10-2020-0146037, filed on Nov. 4, 2020, in the KIPO (Korean Intellectual Property Office), the disclosure of which is incorporated herein entirely by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a test apparatus for a semiconductor package, and more particularly, to a test apparatus for a semiconductor package for inspecting whether normal operation of a package-on-package (POP) type semiconductor package formed by vertically stacking a lower package and an upper package.

Description of the Related Art

A semiconductor package is formed by integrating fine electronic circuits at a high density, and during a manufacturing process, a test process is performed to check whether each electronic circuit is normal. The test process is a process for selecting normal products and defective products by testing whether the semiconductor package is being normally operated.

For testing a semiconductor package, a test apparatus which electrically connects a terminal of the semiconductor package to a tester applying a test signal is utilized. The test apparatus has various structures depending on the type of semiconductor package to be tested.

Recently, as use of a package-on-package (POP) type semiconductor package which minimizes component size and enables signal to be rapidly transmitted has been increased, demand for the test apparatus for testing such semiconductor package has also been steadily continuing.

The package-on-package type semiconductor package is manufactured by sequentially stacking one package on a package performing different function. In a case of a semiconductor package used in a smartphone or tablet PC, in order to implement a three-dimensional package through a vertical expansion, the semiconductor package takes the form of a package-on package in which an application processor (AP), a baseband chip, and a memory are stacked. The package-on-package method can minimize a length of connection wiring to minimize loss such as signal delay and impedance mismatch occurred during a two-dimensional arrangement. In addition, since this method utilizes the spatial vertical direction, a mounting area per unit area can be maximized to realize a large-capacity and micro-element.

In addition, since in the package-on-package method, the tested packages are stacked, so the yield can be increased. For example, in the case of manufacturing each of a logic device and memory device in one package, if one of the two devices is changed, the entire test program and a tester board must be modified, resulting in a problem in that a lot of time and cost are required. However, in the package-on-package method, packages are stacked after each of the logic package and the memory package is tested. Therefore, when a change to any package is occurred, only a test tool for the corresponding package needs to be changed, so this method has the advantage of dramatically reducing time and cost

A conventional test apparatus for testing a package-on-package type semiconductor package includes a lower test socket having a pogo pin used to transmit an electrical signal, an upper test socket, and a pusher body coupled to the upper test socket. The lower test socket is installed on the tester board to be electrically connected to a lower package, and an upper package is mounted on the upper test socket to be electrically connected to the upper test socket.

However, in the conventional test apparatus, since a length of signal transmission path between the upper package and the lower package is long, signal distortion is easy to occur in high-speed signal transmission. Therefore, there is a problem in that it is impossible to precisely inspect a semiconductor package that is operated at high speed.

In addition, addition, in the conventional test apparatus, since a plurality of holes are formed in the upper test socket in order to install the pogo pins for electrically connecting the upper package and the lower package, when vacuum pressure is supplied to a pusher to pick up the semiconductor, a pick-up error is easily to occur.

The above-described information disclosed in the background description is provided only for improving the understanding of the background of the present disclosure, and thus may include the information which does not constitute the prior art.

SUMMARY OF THE INVENTION

The present disclosure is conceived in view of the above points, and an object of the present disclosure is to provide a test apparatus for a semiconductor package capable of accurately testing a package-on-package type semiconductor package which is operated at high speed.

In addition, another object of the present disclosure is to provide a test apparatus for a semiconductor package capable of preventing a pickup error when a semiconductor package is picked-up.

Furthermore, still another object of the present disclosure is to provide a test apparatus for a semiconductor package capable of extending the life of a semiconductor package and a test socket.

In order to achieve the above object, a test apparatus for a semiconductor package according to the present disclosure is a test apparatus for a semiconductor package for testing a package-on-package (POP) type semiconductor package and includes a lower socket mounted to a tester board providing a test signal, and provided with a plurality of socket pins connected to a lower terminal of a lower package to electrically connect the lower package and the tester board to each other; a pusher to which an upper package is coupled, the pusher having a pusher body which may be moved to approach the lower socket or to be moved away from the lower socket; and an upper socket coupled to the pusher body, and provided with an insulating pad formed of a nonelastic insulating material and a plurality of electrically-conductive parts supported on the insulating pad, the electrically-conductive part being formed of an elastic insulating material containing a plurality of electrically-conductive particles such that one end thereof may be connected to an upper package terminal of the upper package and the other end thereof may be connected to an upper terminal of the lower package.

In the test apparatus for a semiconductor package according to the present disclosure, the electrically-conductive part may include an electrically-conductive part bump which protrudes from a lower surface of the insulating so as to be compressed to the upper terminal of the lower package.

The test apparatus may include a compression control sheet attached to a lower surface of the insulating pad and having a through hole formed therein to surround a lower end portion of the electrically-conductive bump, with a space part being formed between the through hole and the lower end portion of the electrically-conductive bump.

The volume of the space part of the through hole is included in a range greater than 0.2 times and less than 1.2 times the volume of the upper end portion of the electrically-conductive bump.

In the test apparatus for a semiconductor package according to the present disclosure, a surface of the upper package terminal may be coated with an oxidation-inhibiting metal.

In the test apparatus for a semiconductor package according to the present disclosure, a PCB connecting body may be inserted between the upper package and the upper socket, the PCB connecting body may be provided with pads which are coated with an oxidation-inhibiting metal and mounted on upper and lower surfaces, respectively, of a via having an electrically-conductive path formed on an inner wall or an inner surface thereof, the upper package terminal may be in contact with the pad mounted on the upper surface, and the electrically-conductive part of the upper socket may be in contact with the pad mounted on the lower surface.

The oxidation-inhibiting metal may be gold, palladium, rhodium, cobalt, or an alloy of two or more metals thereof.

The test apparatus for a semiconductor package according to the present disclosure may further include an adsorption pad provided with a suction hole to which vacuum may be supplied through the pusher, and coupled to the insulating pad so as to adsorb the lower package.

The adsorption pad may be movably disposed in an insulating pad hole provided in the insulating pad.

The pusher includes a chamber provided in the pusher body to be opened outward for receiving the upper package therein, and the upper socket may be coupled to the pusher body to seal the chamber.

The test apparatus for a semiconductor package according to the present disclosure may further include a guide housing provided with a receiving groove capable of receiving the lower package therein and disposed above the lower socket, and the pusher may include a catching jaw provided on the pusher body so as to come into contact with the guide housing, thereby limiting a moving distance of the pusher body approaching the lower socket.

The test apparatus for a semiconductor package according to the present disclosure may further include a guide housing provided with a receiving groove capable of receiving the lower package therein and disposed above the lower socket, and an alignment hole may be provided in one of the pusher body and the guide housing, and an alignment pin to be inserted into the alignment hole so as to align the pusher body approaching the lower socket may be provided in the other one of the pusher body and the guide housing.

The pusher may include a buffering unit coupled to the pusher body to buffer pressure applied to the pusher body from a driving part for limiting a load applied to the lower package by the upper socket.

The test apparatus for a semiconductor package according to the present disclosure may further include a support film provided with a plurality of film holes into which the upper package terminals of the upper package may be inserted, and disposed between the upper package and the upper socket to space the upper package and the upper socket apart from each other.

In the test apparatus for a semiconductor package according to the present disclosure,

as compared with a conventional test apparatus having a pogo pin structure, a length of signal transmission path is short, so it is possible to prevent signal distortion in high-speed signal transmission and to perform a precision test for a semiconductor package that is operated at high speed.

In addition, in the test apparatus for a semiconductor package according to the present disclosure, there is little risk of leakage of the vacuum pressure between the pusher and the adsorption pad providing for adsorbing the lower package, and by adopting a configuration in which the vacuum pressure is stably transmitted from the pusher to the adsorption pad, it is possible to reduce a pickup error when the lower package is picked-up.

In addition, in the test apparatus for a semiconductor package according to the present disclosure, contact resistance between the electrically-conductive part of the upper socket and the terminal of the upper package is minimized, and the compression amount of the electrically-conductive part of the upper socket can be adjusted according to a test environment, so there is the effect of extending a life of the upper package and the upper socket.

DETAILED DESCRIPTION

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes”, “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. In addition, a term such as a “unit”, a “module”, a “block” or like, when used in the specification, represents a unit that processes at least one function or operation, and the unit or the like may be implemented by hardware or software or a combination of hardware and software.

Reference herein to a layer formed “on” a substrate or other layer refers to a layer formed directly on top of the substrate or other layer or to an intermediate layer or intermediate layers formed on the substrate or other layer. It will also be understood by those skilled in the art that structures or shapes that are “adjacent” to other structures or shapes may have portions that overlap or are disposed below the adjacent features.

In this specification, the relative terms, such as “below”, “above”, “upper”, “lower”, “horizontal”, and “vertical”, may be used to describe the relationship of one component, layer, or region to another component, layer, or region, as shown in the accompanying drawings. It is to be understood that these terms are intended to encompass not only the directions indicated in the figures, but also the other directions of the elements.

Hereinafter, a test apparatus for a semiconductor package according to preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

FIG.1is a view schematically showing a test apparatus for a semiconductor package according to one embodiment of the present disclosure, andFIG.2is a view for explaining operation of the test apparatus for a semiconductor package according to one embodiment of the present disclosure.

As shown in the drawings, a test apparatus100for a semiconductor package according to one embodiment of the present disclosure is utilized for testing a package-on-package type (POP) semiconductor package including a lower package10and an upper package20, and may electrically connect a tester board30generating a test signal and the package-on-package type (POP) semiconductor package. The test apparatus100for a semiconductor package includes a lower socket110mounted to the tester board30, a guide housing120coupled to the lower socket110, a pusher130which may be moved by a moving force transmitted from a driving part40thereto, an upper socket140coupled and mounted to the pusher130, and an adsorption pad150disposed on the upper socket140to adsorb the lower package10.

The lower socket110is mounted to the tester board30to electrically connect the tester board30and the lower package10to each other. The lower socket110includes a socket housing111and a plurality of socket pins112disposed inside the socket housing and spaced apart from each other. The socket pin112is formed of an electrically-conductive material so as transfer an electrical signal. One end of the socket pin112comes into contact with an electrode (not shown) provided on the tester board30, and the other end of the socket pin112comes into contact with a lower terminal11of the lower package10placed on the socket housing111. As shown in the drawings, the other end of the socket pin112is received in a socket groove113provided in an upper surface of the socket housing111and may thus come into contact with the lower terminal11of the lower package10placed above the socket groove113.

In addition to the illustrated configuration, the lower socket110may be modified to have various other structures by which the lower socket may be mounted to the tester board30to electrically connect the tester board30and the lower package10.

The guide housing120is installed on the lower socket110. The guide housing120is provided with a receiving groove121in which the lower package10may be received. The receiving groove121may be formed to pass through the guide housing120in the vertical direction. The lower package10may reach the lower socket110through the receiving groove121of the guide housing120. The guide housing120is provided with an inclined surface122. The inclined surface122may guide the pusher130which is being moved downward towards the lower socket110. That is, when the upper socket140is moved towards the lower socket110in a state where the pusher130is biased towards one side, the pusher130may come into contact with the inclined surface122to be guided along the inclined surface122. Accordingly, the pusher130may align the upper package20to a normal position on the lower package10.

In addition to the illustrated configuration, the guide housing120may be modified to have various other structures in which the lower package10may be placed therein.

The pusher130includes a pusher body131which may be moved to approach the lower socket110or to be moved away from the lower socket110by receiving the moving force from the driving part40. A chamber132capable of receiving the upper package20therein and a vacuum hole133configured to transmit vacuum pressure are provided inside the pusher body131. The chamber132is opened outward from one side of the pusher body131. The vacuum hole133may be in communication with an external vacuum pressure generator (not shown) to transmit the vacuum pressure generated in the vacuum pressure generator to the chamber132.

The above pusher130may be moved by the driving part40in a state where the upper socket140and the upper package20are coupled, to connect the upper socket140to the lower package10placed on the lower socket110or space the upper socket140apart from the lower package10. In addition, the pusher130may load the lower package10onto the lower socket110or unload the lower package10from the lower socket110as it approaches the lower socket110or is moved away from the lower socket110.

In addition to the illustrated configuration, the pusher130may be modified to have various other structures in which the upper socket140and the upper package20are mounted and may be moved by the driving part40.

The upper socket140is coupled to one side of the pusher body131to enable the chamber131to be sealed. The upper socket140is electrically connected to the upper package20placed in the chamber132. The upper socket140includes an insulating pad141covering the chamber132and a plurality of electrically-conductive parts144supported by the insulating pad141.

The insulating pad141may be formed of a nonelastic insulating material. The insulating pad141made of a nonelastic insulating material is advantageous to pressurize the lower package10towards the lower socket110when the upper socket140comes into contact with the lower package10. When the insulating pad141stably pressurizes the lower package10, the lower terminal11of the lower package10may be stably connected to the socket pin112of the lower socket110. Various synthetic resins may be utilized as the nonelastic insulating material used for manufacturing the insulating pad141.

The insulating pad141is provided with an insulating pad hole142. The insulating pad hole142is in communication with the chamber132so that the vacuum pressure in the chamber132can be transmitted.

The electrically-conductive part144is supported on the insulating pad141so as to pass through the insulating pad141in the thickness direction. One end of the electrically-conductive part144may be in contact with an upper package terminal21of the upper package20and the other end thereof may be connected to an upper terminal12of the lower package10. The electrically-conductive part144includes an electrically-conductive part body145placed in the insulating pad141and an electrically-conductive part bump146connected to the electrically-conductive part body145so as to protrude from a lower surface of the insulating pad141. When the upper socket140approaches the lower socket110, the electrically-conductive part bump146is compressed to the upper terminal12of the lower package10, so it may stably come into contact with the upper terminal12. The electrically-conductive part144may be formed to have a configuration in which a plurality of electrically-conductive particles are included in an elastic insulating material.

In addition, as the electrically-conductive particles constituting the electrically-conductive part144, particles having magnetism may be employed such that is may be reacted by a magnetic field. For example, as the electrically-conductive particles, particles obtained by plating a surface of core particle, for example, particles of metals exhibiting magnetism, such as iron, nickel, cobalt, etc., or alloy particles thereof, or particles containing these metals, or particles of these metals, with a metal having excellent electrical-conductivity, such as gold, silver, palladium, radium, or the like; particles obtained by plating a surface of core particle, for example, non-magnetic metal particles, inorganic substance particles such as glass beads or the like, and polymer particles, with electrically-conductive magnetic substance such as nickel, cobalt, or the like; or particles obtained by plating core particle with electrically-conductive magnetic substance and a metal having excellent electrical-conductivity may be employed.

A support film160is disposed on the upper socket140. The support film160is interposed between the upper package20and the upper socket140to space the upper package20and the upper socket140apart from each other. A plurality of film holes161are formed in the support film160to pass through the support film160in the thickness direction. The upper package terminal21of the upper package20is inserted into the film hole161, so the upper package terminal21may come into contact with the electrically-conductive part144through the film hole161. At least one of the pluralities of film holes161is in communication with the insulating pad hole142of the insulating pad141, and the vacuum pressure in the chamber132may transmitted to the insulating pad hole142through the film hole161.

The support film160may be formed of a nonelastic insulating material, or other various insulating materials capable of spacing the upper package20and the upper socket140apart from each other.

The adsorption pad150may be coupled to the insulating pad141to adsorb the lower package10. The adsorption pad150includes a suction hole151through which the vacuum pressure may be provided from the chamber132. At least a portion of the adsorption pad150may be inserted into the insulating pad hole142of the insulating pad141, and the suction hole151may be in communication with the chamber132through the insulating pad hole142. The adsorption pad150may be moved in the insulating pad hole142. When the upper socket140is connected to the lower package10, the adsorption pad150may enter the insulating pad hole142such that the adsorption pad150does not interfere with a connection between the upper socket140and the lower package10.

As described above, in the test apparatus100for a semiconductor package according to an embodiment of the present disclosure, in the state where the upper socket140and the upper package20are mounted to the pusher body131, the pusher130may be moved by the driving part40to transport the lower package10over the lower socket110. That is, the pusher130approaches over the lower package10which is being in a standby position to allow the adsorption pad150to adsorb the lower package10, and the pusher130may be moved over the lower socket110to load the lower package10onto the lower socket110. At this time, the lower terminal11of the lower package10is connected to the socket pin112of the lower socket110.

Thereafter, as shown inFIG.2, as the pusher130is moved towards the lower socket110, the electrically-conductive part144of the upper socket140is connected to the upper terminal12of the lower package10. At this time, since a pressurizing force of the pusher130is transmitted to the lower package10through the upper socket140, the lower package10can maintain a stable connection state to the lower socket110. As the upper socket140is connected to the lower package10, the tester board30, the lower socket110, the lower package10, the upper socket140, and the upper package20are electrically connected to each other. In this state, the test signal generated in the tester board30is transmitted to the lower package10and the upper package20, so an electrical test for the lower package10and the upper package20may be formed.

After the test is completed, the lower package10may be adsorbed on the adsorption pad150and then unloaded from the lower socket110according to a movement of the pusher130.

As described above, in the test apparatus100for a semiconductor package according to one embodiment of the present disclosure, as compared with a conventional test apparatus having a pogo pin structure, a length of a signal transmission path is short, so it is possible to prevent signal distortion in high-speed signal transmission and it is possible to perform a precision test for a semiconductor package which is operated at a high speed.

In addition, in the test apparatus100for a semiconductor package according to one embodiment of the present disclosure, there is little risk of leakage of the vacuum pressure between the pusher130and the adsorption pad150providing for adsorbing the lower package10, and by adopting a configuration in which the vacuum pressure is stably transmitted from the pusher130to the adsorption pad150, it is possible to reduce a pickup error when the lower package10is picked-up.

Meanwhile,FIGS.3to5are views showing various modified examples of the test apparatus for a semiconductor package according to the present disclosure.

First, a test apparatus200of the semiconductor package shown inFIG.3includes the lower socket110mounted to the tester board30, the guide housing120coupled to the lower socket110, a pusher210which may be moved by a moving force transmitted from the driving part40thereto, the upper socket140coupled and mounted to the pusher210, and an adsorption pad150disposed on the upper socket140to adsorb the lower package10. In the test apparatus200for such a semiconductor package, a configuration of the pusher210is partially modified.

As compared with the above-described pusher130, the pusher210further includes a catching jaw211provided on the pusher body131so as to come into contact with the guide housing120, thereby limiting a moving distance of the pusher body131. When the pusher body131approaches the lower socket110, the catching jaw211comes into contact with an upper end portion of the guide housing120, so the pusher body131is stopped. In this way, by limiting the moving distance of the pusher body131which is moved towards the lower socket110, using the catching jaw211, it is possible to limit the amount of contact stroke obtained when the upper socket140comes into contact with and pressurizes the lower package10. In addition, by limiting the amount of the contact stroke, the load applied to the lower package10may be limited so as not to be excessive.

In this embodiment, a separate stopper part corresponding to the catching jaw211of the pusher210may be provided in the guide housing120. The stopper part may take various configurations according a shape of the catching jaw211and the like.

A test apparatus300for a semiconductor package shown inFIG.4includes the lower socket110mounted to the tester board30, the guide housing120coupled to the lower socket110, a pusher310which may be moved by a moving force transmitted from the driving part40thereto, the upper socket140coupled and mounted to the pusher310, and the adsorption pad150disposed on the upper socket140to adsorb the lower package10.

The pusher310includes an alignment pin320protruding from the pusher body131. The alignment pin320is provided for aligning the pusher body131, which is approaching the lower socket110, on the lower package10. An alignment hole330into which the alignment pin320may be inserted is provided in the guide housing120.

When the pusher body131approaches the lower socket110, the alignment pin320is inserted into the alignment hole330, so the pusher body131may be guided to approach the lower socket110in a certain posture. By action of the alignment pin320and the alignment hole330, the electrically-conductive part144of the upper socket140may accurately come into contact with the upper terminal12of the lower package10.

The number or arrangement structure of the alignment pin320and the alignment hole330may be variously modified. In addition, a configuration in which the alignment pin320is provided in the guide housing120and the alignment hole330is provided in the pusher body131is also possible.

A test apparatus400for a semiconductor package shown inFIG.5includes the lower socket110mounted to the tester board30, the guide housing120coupled to the lower socket110, a pusher410which may be moved by a moving force transmitted from the driving part40thereto, the upper socket140coupled and mounted to the pusher410, and the adsorption pad150disposed on the upper socket140to adsorb the lower package10.

The pusher410includes a buffering unit420. The buffering unit420serves to buffer a load applied to the pusher body131from the driving unit40. The buffering unit420may be formed of a material having elasticity such as rubber, silicone or the like, or may take various structures capable of absorbing shock, such as a structure including a spring. Due to buffering action of the buffering unit420, when the upper socket140is connected to the lower package10, the load applied to the lower package10by the upper socket140may be limited so as not to be excessive. The buffering unit420may be supported by a connection member430connected to the driving part40.

A technique for preventing oxidation between the upper package terminal21of the upper package20and the electrically-conductive part144of the upper socket140or a technique for controlling the compression amount of the electrically-conductive part bump146of the upper socket140may applied to the test apparatuses100,200,300, and400for a semiconductor package for testing a package-on-package (POP) type semiconductor package according to the present disclosure. Of course, it is also possible to apply both of the above techniques to the above apparatuses.

As for this, the test apparatus100of the semiconductor package shown inFIG.1will be described as an example.

In the test apparatus for testing a package-on-package (POP) type semiconductor package, there is a case where the upper package20may be a normal package secured in advance to test the lower package10. By connecting the upper package terminal21in the form of a solder ball of the upper package20, which is a normal package, to the upper terminal12of the lower package10, which is under test, through the electrically-conductive part144of the upper socket140, it is possible to inspect whether the lower package10is being normally operated.

However, if the upper package terminal21comes into contact with the electrically-conductive part144of the upper socket140to allow an electrical current to flow therethrough, heat is generated between contact portions of the above two elements due to contact resistance, and tin (Sn) which is a main material of the upper package terminal21is oxidized by heat generated in the contact portions. In addition, as the inspection is repeated, oxidation of the upper package terminal21is increased, so contact resistance is further increased. For this reason, there is a problem in that, after tens to hundreds of repetitive inspections have been performed, it is difficult to form electrical connection due to high resistance, and therefore normal inspection of the lower package10is thus impossible.

Therefore, by coating a surface of the upper package terminal21with a metal that prevents surface oxidation, for example, a metal such as gold, palladium, rhodium, cobalt, or the like or an alloy of two or more of the above metals, even in repeated use, it is possible to prevent an increase in contact resistance between the electrically-conductive part144and the upper package terminal21due to oxidation of the upper package terminal. Accordingly, it is possible to enhance the inspection reliability of the lower package10.

More preferably, it is preferable to apply nickel plating on a surface of the upper package terminal21first, and then coat the nickel-plated surface with an oxidation-inhibiting metal. Although oxidation of the upper package terminal21can be prevented by using only the oxidation-inhibiting metal such as gold, in the case of using gold, due to its characteristics, gold has a strong property of being absorbed and alloyed by other metals such as tin, which is the main material of the upper package terminal21, and thus contact resistance may be increased after a large number of tests. However, if an under layer such as nickel is provided, since gold does not alloy with nickel, the normal upper package20can be used for inspection of the lower package10for a longer time.

As a method of coating the surface of the upper package terminal21, for example, a brush plating method may be utilized. The brush plating method is a partial plating method using an electroplating technology, and does not use a plating bath as in general wet plating, and partial plating is possible using a dedicated brush tool and a rectifier. Accordingly, it is possible to easily coat a surface of solder ball with the oxidation-inhibiting metal using the brush plating method.

On the other hand, in the upper package terminal21in the form of a solder ball, deformation of the solder ball shape may be occurred due to repeated contact between the upper package terminal and the electrically-conductive part144. Therefore, after the upper package terminal21in the form of a solder ball is melted at a high temperature and removed, a surface of the removed terminal may be coated with an oxidation-inhibiting metal, for example gold, palladium, rhodium, cobalt, or an alloy of two or more of these metals and utilized as the upper package terminal. The upper package terminal21formed in this way can an effect that it can be used even in a high temperature environment without deformation of an external shape of the terminal.

In order to reduce contact resistance between the upper package terminal21and the electrically-conductive part144of the upper socket140, in addition to the above-described method of coating the surface of the solder ball of the upper package terminal21with an oxidation-inhibiting metal, a method of inserting a PCB connecting body170between the upper package20and the upper socket140is also possible.

As shown inFIG.6, pads172coated with the oxidation-inhibiting metal are formed on upper and lower surfaces of a via171of the PCB connecting body170having an electrically-conductive path formed on an inner wall or an inner surface thereof, if the upper package terminal21and the electrically-conductive part144of the upper socket140are brought into contact with each other through the pads172of the PCB connecting body, even though repetitive inspections are performed, it is possible to prevent an increase in contact resistance due to the pads172coated with an oxidation-inhibiting metal. Therefore, the upper package20, which is a normal package, enables stable and reliable inspection of more lower packages10.

When using a method of reducing contact resistance between the upper package terminal21and the electrically-conductive part144of the upper socket140by using the PCB connector170, it is preferable to remove the support film160shown inFIG.1, and it is preferable that the electrically-conductive part144is formed to have a configuration in which the electrically-conductive part upper bump partially protrudes upward so that it can be more stably brought into contact with the pad172of the PCB connector170having a flat shape.

In addition, as shown inFIG.7, in the test apparatus for testing a package-on-package (POP) type semiconductor package, a compression control sheet180having a predetermined thickness may be attached on a lower portion of the upper socket140, that is, the lower surface of the insulating pad141.

The compression control sheet180is an integral type sheet in which a through hole181having a diameter larger than that of the electrically-conductive part bump146is formed at a position thereof corresponding to the electrically-conductive part bump146, this compression control sheet may be formed to have a thickness which is about half of the thickness of the electrically-conductive part bump146, and is attached to surround the lower end portion1461of the electrically-conductive part bump146of the insulating pad141with the space part190interposed therebetween. Therefore, the space part190is provided in a region obtained by excluding a region occupied by the electrically-conductive bump146(that is, a region of the lower end portion1461of the electrically-conductive bump146) from a region of the through hole181of the compression control sheet146.

In addition, an upper end portion1462of the electrically-conductive part bump146is defined as a portion protruding from the compression control sheet180.

A height of the upper end portion1462of the electrically-conductive part bump146, that is, a height of the portion protruding from the compression control sheet180may be appropriately selected according to a diameter of the electrically-conductive part, a pitch of the electrically-conductive part, etc., but is preferably in the range of 5 μm to 500 μm, more preferably in the range of 10 μm to 300 μm, and most preferably in the range of 25 μm to 200 μm.

The compression control sheet180may be formed of a material which is the same as that of the insulating pad141. Therefore, the compression control sheet180may be formed of a nonelastic insulating material such as various synthetic resins. Of course, the compression control sheet180and the insulating pad141may be formed of different materials.

The space part190formed between the compression control sheet180and the electrically-conductive part bump146serves as a space controlling the compression amount of the electrically-conductive part bump146. When the upper socket140is pressurized by the pressurizing force of the pusher130, the electrically-conductive part bump146can be compressed until the lower surface of the insulating pad141comes into contact with an upper surface of the lower package10, so durability of the upper socket140may be deteriorated due to excessive compressive deformation of the electrically-conductive part bump146.

Accordingly, in the present disclosure, by providing the space part190in the compression control sheet180and adjusting volume of the space part190, the characteristics of the upper socket140required in various test environments may be provided. When the volume is reduced, the pressurizing force of the pusher130can be increased, so contact load between the upper socket and the upper terminal12of the lower package10can be increased, and thus the electrical conductivity can be further enhanced. Conversely, if the volume is increased, the contact load can be reduced, so the life of the upper socket can be extended. The present disclosure is advantageous in that it is possible to adjust the characteristics of the test socket according to the test environment as described above.

In addition, if the volume of the space part190is small, the electrically-conductive part bump146is compressed, and the compression control sheet180supports a portion of the electrically-conductive part bump146received in the space part190, and thus deformation of the electrically-conductive part bumps146can be prevented. Furthermore, if the volume of the space part is increased, even if the electrically-conductive part bump146is compressed as much as possible, excessive compressive deformation of the electrically-conductive part bump146may be prevented by compressing it until only a lower surface of the compression control sheet180which is formed of a nonelastic material.

It is preferable that the volume of the space part190of the through hole181is included in a range greater than 0.2 times and less than 1.2 times the volume of the upper end portion1462of the electrically-conductive bump146. When the volume of the space part190is less than 0.2 times the volume of the upper end portion1462of the electrically-conductive part bump146, the deformation amount of the electrically-conductive part bump146cannot be sufficiently absorbed by the space part, and when the volume of the space part190is 1.0 times the volume of the upper end portion1462of the electrically-conductive part bump146, the space part can theoretically absorb the entire volume of the upper end portion1462of the electrically-conductive part bump146, However, since compression may not be smoothly performed due to flexibility of the electrically-conductive part bump146, in order to facilitate compression, the volume of the space part190is preferably set to a range which is slightly larger than the volume of the upper end portion1462of the electrically-conductive part bump146, but smaller than 1.2 times the volume of the upper end portion1462.

Although the present disclosure has been described with a preferred example, a scope of the present disclosure is not limited to the form described and illustrated above.

For example, although a configuration in which the electrically-conductive part144of the upper socket140has the electrically-conductive part bump146protruding from the insulating pad141is illustrated in the drawings, if the lower package10is formed to have a configuration in which the upper terminal12thereof protrudes, the electrically-conductive part144may be formed to have a configuration in which it does not have the electrically-conductive part bump146.

In addition, although a configuration in which the vacuum pressure supplied through the vacuum hole133of the pusher body131is transmitted to the adsorption pad150through the chamber132is illustrated in the drawings, a flow passage structure for transmitting the vacuum pressure supplied to the vacuum hole133to the adsorption pad150may be variously modified. As another example, it is possible to transmit the vacuum pressure to the insulating pad hole142of the insulating pad141via a gap formed between a lower end portion of the upper package20and an upper end portion of the upper socket140by removing a portion of the support film160.

While the present disclosure has been described with reference to the embodiments illustrated in the figures, the embodiments are merely examples, and it will be understood by those skilled in the art that various changes in form and other embodiments equivalent thereto can be performed. Therefore, the technical scope of the disclosure is defined by the technical idea of the appended claims The drawings and the forgoing description gave examples of the present invention. The scope of the present invention, however, is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of the invention is at least as broad as given by the following claims.