TEST BOARD, AND DIAGNOSTIC SYSTEM, DIAGNOSTIC METHOD, AND NON-TRANSITORY COMPUTER-READABLE STORAGE MEDIUM STORING DIAGNOSTIC PROGRAM OF THE TEST BOARD

According to a certain embodiment, a test board on which a device under test and a test executable integrated circuit configured to execute a test of the device under test are mounted, includes a first input/output terminal, a second input/output terminal, and a contact unit. The first input/output terminal connects a first measuring apparatus capable of supplying electric power to the test board and controlling the test executable integrated circuit. The second input/output terminal connects a second measuring apparatus capable of measuring electrical characteristics of the test executable integrated circuit. The contact unit is mounted on the test board through the second input/output terminal, and capable of electrically connecting the second measuring apparatus. There are provide the test board; and a diagnostic system, a diagnostic method, and a non-transitory computer-readable storage medium storing a diagnostic program, capable of diagnosing the test executable integrated circuit mounted on the test board.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. P2022-139236 filed on Sep. 1, 2022, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a test board; and a diagnostic system, a diagnostic method, and a non-transitory computer-readable storage medium storing a diagnostic program of such a test board.

BACKGROUND

Semiconductor devices are subjected to stress tests for suppressing an occurrence of initial failures, reliability tests for verify reliability of products, and the like. Such stress tests include, for example, burn-in (BI) tests and the like, and such reliability tests include, for example, environmental tests, long-term life tests, and the like. In the burn-in tests, a burn-in board (BI board) is used as a test board on which a plurality of semiconductor devices are mounted as devices under test (DUT).

DETAILED DESCRIPTION

Next, certain embodiments will now be explained with reference to drawings. In the description of the following specification or drawings to be explained, the identical or similar reference sign is attached to the identical or similar part. However, the drawings are merely schematic. Moreover, the embodiments described hereinafter merely exemplify a device and/or a method for materializing the technical idea. The embodiments may be changed without departing from the spirit or scope of claims.

Certain embodiments provide a test board; and a diagnostic system, a diagnostic method, and a non-transitory computer-readable storage medium storing a diagnostic program of the test board, capable of diagnosing a test executable integrated circuit mounted on the test board.

According to one embodiment, a test board on which a device under test and a test executable integrated circuit configured to execute a test of the device under test are mounted, includes a first input/output terminal, a second input/output terminal, and a contact unit. The first input/output terminal connects a first measuring apparatus capable of supplying electric power to the test board and controlling the test executable integrated circuit. The second input/output terminal connects a second measuring apparatus capable of measuring electrical characteristics of the test executable integrated circuit. The contact unit is mounted on the test board through the second input/output terminal, and capable of electrically connecting the second measuring apparatus.

In recent memory products, speed of interfaces (IF) thereof has been improved, making it necessary to apply stress not only to memory cells but also to peripheral circuits thereof in burn-in tests. For this reason, a System-On-a-Chip (SoC) may be mounted as a test executable integrated circuit on a burn-in board, and tests may be performed with a high-speed IF through the SoC. In such an SoC-mounted burn-in board, it is also necessary to perform diagnostics for guaranteeing an operation of the SoC itself mounted on the burn-in board.

In semiconductor devices, such as semiconductor memories, devices have been evaluated from various aspects under various test conditions before being shipped to the market in order to avoid market defects. For example, there have been performed a burn-in test for suppressing occurrence of an initial failures generating, a reliability test for verifying reliability of products, and the like.

In a general burn-in test of memory products, a test board (e.g., a burn-in board) on which a device under test (DUT) is mounted is set in a test apparatus (e.g., a burn-in apparatus), and stresses, such as a voltage stress and a thermal stress, are continuously applying to the DUT mounted on the burn-in board. The time required for the test (i.e., test time) is generally long, from several hours to several tens of hours. Accordingly, the time occupied by the burn-in apparatus and the burn-in board becomes longer, and the cost also increases. Therefore, such a burn-in apparatus and such a burn-in board have a configuration capable of simultaneously burn-in of a large number of the DUTs. In such a configuration, DUT's control and data lines are shared among a plurality of DUTs. As a result, a load on the DUT increases, the time required for a driver (driving unit) provided in the burn-in apparatus to drive the DUT increases, and the test time also increases. More specifically, since a single driving unit provided in the burn-in apparatus must drive a large number of DUTs in the burn-in test, the rise time of each of the DUTs is slower and the transition time is longer than those in a case where a single driving unit drives a single DUT.

Moreover, in recent memory products, peripheral circuits have also been more complicated as the speed of interfaces has improved. As a result, there have been an increasing number of cases of early failure of such peripheral circuits. For example, wiring disconnection caused by step have become a problem in buffer circuits of high-speed interfaces. Therefore, it has become necessary to apply stresses not only to the memory cells but also to peripheral circuits (for example, output stage) thereof, in the burn-in test process.

In such cases, since the test speed cannot be increased in a burn-in test using a normal burn-in board, a burn-in board on which a test executable integrated circuit, such as an SoC, is mounted is used. The SoC is, for example, an Application-Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or the like for executing tests on a DUT.

The SoC is an integrated circuit for inspecting the DUT, and, for example, if the DUT is a memory device, the SoC is a memory controller. However, since the SoC merely needs to control the memory device, the SoC itself does not necessarily need to mount a CPU thereon.

Test items for DUTs executed by the SoCs include an electrical conductivity test, a DC test, a functional test, an AC test, a SCAN test (structural test), a power supply-related test, and the like. If the DUT is an NAND flash memory, cell tests of the NAND memory include: a Pass/Fail test, such as SLC (1 bit/cell), MLC (2 bits/cell), TLC (3 bits/cell), and QLC (4 bits/cell); a test acceptable of a certain error as an error bit test;

a fail bit count test exceeding an ECC correction capability required for the cell test as a fail bit count test; an Okay/No-Good determination test of tPROG criteria as a tPROG criteria test, and the like.

Since such an SoC-mounted burn-in board tests the DUT through the mounted SoC, it can be tested with a high speed interface. It is to be noted that since the SoC and the DUT are connected one-to-one, the load thereof is reduced and testing can be executed at higher speeds. However, the higher the test speed, the shorter the distance between each SoC and each DUT must be, so the SoC must inevitably be mounted near the DUT.

However, if the SoC is mounted near the DUT during the burn-in test, the SoC is also subjected to a thermal stress in a chamber, such as a thermostatic oven. A mechanism so as to isolate the SoC from the thermal stress of the chamber may not be adopted since the cost of the burn-in apparatus increases. In such cases, since the SoC may also be subjected to the thermal stress, it is necessary to verify in advance that the SoC normally operates before executing the burn-in test.

Thus, in the case of adopting the SoC-mounted burn-in board, it is required to diagnose the SoC-mounted burn-in board in order to guarantee the operation of the SoC mounted on the board. More specifically, semiconductor components are generally deteriorated in performance over time even if the semiconductor components are used within a guaranteed operating temperature range. Moreover, since the degree of deterioration must not affect burn-in test results, it is necessary to verify whether or not the SoC has a proper performance capable of guaranteeing the test.

When executing a screening of initial failures of semiconductor devices, a measuring instrument capable of measuring electric current and voltage, such as a tester, is generally used. However, such burn-in apparatuses generally do not have a mechanism so as to measure an electrical quantity of the burn-in board. This is because the burn-in test itself does not require such a measuring instrument, or because the wirings are shared between a large number of the SoCs, as above-mentioned above, and therefore it cannot realize accurate measurement of the electric current and voltage in each SoC. Therefore, a measuring instrument capable of measuring the electric current and voltage such as a tester is required in order to diagnose the burn-in board.

Diagnostic System in Embodiments

The embodiments disclosed herein are used for diagnostics of test boards, such as a burn-in board, on which a test executable integrated circuits, such as SoC, is mounted. The term burn-in board diagnostics used herein means to accurately diagnose functions and performance of SoCs mounted on the burn-in board.

FIG.1schematically illustrates an example of a schematic structure of a diagnostic system of a burn-in board according to the embodiments. The diagnostic system according to the embodiments includes a burn-in board (e.g., a test board)100, a burn-in apparatus (e.g., a first measuring apparatus)200, a measuring instrument (e.g., a second measuring apparatus)300, and a contact unit400.

The diagnostic system in the embodiments is provided with a configuration for enabling on-board diagnostics of the burn-in board to guarantee an operation of an SoC(s)110in order to enable a burn-in test at high-speed IF, in the burn-in board100on which the SoC110is mounted. The contact unit400capable of electrically connecting the measuring instrument300is provided on a substrate of the SoC-mounted burn-in board100, and all pins of the SoC110are exposed as a metallic terminal on the substrate surface of the burn-in board100on the substrate around the SoC110of the burn-in board100so as to be electrically connected to each pin of the SoC110.

In other words, as illustrated inFIG.1, the diagnostic system in the embodiments includes: a burn-in board100on which a device under test (DUT) is mounted; a test executable integrated circuit (SoC)110(110_1, . . . ,110_n) mounted on the burn-in board100to test the DUT; a burn-in apparatus200capable of supplying power to the burn-in board100and controlling the SoC110; measuring instrument300capable of measuring electrical characteristics of the SoC110; and a contact unit400mounted on the burn-in board100and capable of electrically connecting the measuring instrument300to the SoC. The burn-in apparatus200is capable of supplying power to the burn-in board100and controlling the SoC110mounted on the burn-in board100.

The diagnostic system in the embodiments is provided with a configuration capable of connecting the measuring instrument300capable of executing an electrical inspection in the immediate vicinity of the SoC110on the substrate of the SoC-mounted burn-in board100, and thereby the measuring instrument300can accurately measure an electrical quantity of only the SoC110.

Moreover, the diagnostic system in the embodiments is provided with a configuration for electrically isolating each SoC110even if control and data lines of a plurality of SoC110_1, . . . ,110_nare shared, and thereby the electrical quantity of the individual SoC110can be accurately measured and functions of the SoC110can be accurately diagnosed.

The burn-in board100is a test board on which a device under test (DUT) (not illustrated)) and a test executable integrated circuit (e.g., SoC)110(110_1, . . . ,110_n) configured to execute a test of the DUT is mounted. The burn-in board100includes a burn-in terminal (e.g., first input/output terminal)101, n SoCs110(110_1, . . . ,110_n), n measuring instrument terminals (e.g., second input/output terminals)120(120_1, . . . ,120_n), and n burn-in sockets130(130_1, . . . ,130_n) each of which includes a burn-in socket input/output terminal (e.g., third input/output terminal)135(135_1, . . . ,135_n). The variable n used herein is an integer greater than or equal to 1.

The SoC110and the measuring instrument terminal120are provided for each burn-in socket130. That is, the SoC110_1and the measuring instrument terminal120_1are mounted corresponding to the burn-in socket130_1, and the SoC110_nand the measuring instrument terminal120_nare mounted corresponding to the burn-in socket130_n. The DUT is mounted on the burn-in board100being inserted into the burn-in socket input/output terminal135(also simply referred to as “socket terminal135” in the drawings) of the burn-in socket130.

The burn-in terminal101is a terminal for connecting, to the burn-in board100, the burn-in apparatus200capable of supplying power to the burn-in board100and controlling the SoC.

The measuring instrument terminal120is an input/output terminal for connecting, to the burn-in board100, the measuring instruments300, such as a tester, capable of measuring electrical characteristics of the SoC110.

The measuring instrument terminal120is mounted on the substrate surface of the burn-in board100and includes a metallic terminal125electrically connected to a mounted pin of an SoC110. The mounted pin of the SoC110may include all pins of the SoC110. The metallic terminal(s)125is electrically connected to all input/output pins and power supply pin terminal of the SoC110. All input/output pins that are a mounted pins of the SoC110are connected to a tri state buffer115(illustrated inFIG.4).

The contact unit400is mounted on the burn-in board100through the measuring instrument terminal120and allows the measuring instrument300to be electrically connected to the burn-in board100. The contact unit400is capable of connecting or disconnecting all pins of the SoC110to or from measuring instrument300.

The SoC110mounted on the burn-in board100can be electrically inspected. Moreover, a plurality of SoCs110(110_1, . . . ,110_n) mounted on the burn-in board100can be electrically inspected simultaneously.

As illustrated inFIG.1, the burn-in apparatus200includes a power supply unit210, a control unit220, a driving unit230, and a measuring unit240.

The control unit220executes control of each unit in burn-in apparatus200, i.e., the power supply unit210, the driving unit230, the measuring unit240, and the like, and also executes control of the burn-in board100side through the burn-in terminal101.

The power supply unit210supplies electric power to the DUT inserted into the burn-in socket input/output terminal135on the burn-in board100and the SoC110mounted on the burn-in board100, during the burn-in test. Moreover, also during the diagnostics of the burn-in board, the power supply unit210can supply electric power to the DUT inserted into the burn-in socket input/output terminal135and the SoC110mounted on the burn-in board100, and the contact unit400connected to the measuring instrument terminal120. Alternatively, during the diagnostics of the burn-in board, electric power may be supplied from the measuring instrument300side, through the contact unit400, to the DUT inserted into the burn-in socket input/output terminal135and the SoC110mounted on the burn-in board100.

The driving unit230is configured to drive the SoC110mounted on the burn-in board100, and the contact unit400during the burn-in test. More specifically, a normal burn-in board on which no SoC110is mounted is configured so that a driving unit (driver) tests the DUT, but the burn-in board100on which the SoC110is mounted according to the embodiments is configured so that not a driving unit230but the SoC100tests the DUT. Therefore, in the embodiments, it is the SoC110and the contact unit400provided on the burn-in board100that are driven by the driving unit230in the burn-in apparatus. The DUT is not required during the diagnostics of the burn-in board100on which the SoC110is mounted.

The measuring unit240compares an input voltage with a threshold value of high/low level during the burn-in test.

The measuring instrument300includes a control unit310and a measuring unit320, as illustrated inFIG.1. The measuring unit320includes an ammeter321and a voltmeter322.

The control unit310controls the measuring unit320provided in the measuring instrument300and also controls the contact unit400and the burn-in board100side through the contact unit400.

The measuring unit320executes an electrical inspection and the like for guaranteeing an operation of the SoC110mounted on the substrate of the burn-in board100. The electrical inspection includes, for example, a direct current (DC) test, a functional test, and the like. The measuring instrument300includes general-purpose measuring instruments, such as a tester, a voltage and current measuring device, an oscilloscope, and a pulse generator, for example.

The contact unit400includes a relay circuit410and a connector420, as illustrated inFIG.1. The connector420is electrically connected to the measuring instrument terminal120(e.g., any one of the measuring instrument terminals120_1, . . . ,120_n) disposed on the substrate of the burn-in board100.

The relay circuit410is configured so that each pin of the contact unit400can be connected to an electrical quantity metering pin of the measuring instrument300. The contact unit400is a connecting component including a metallic terminal to be connected to the metallic terminal125at the side of the substrate of the burn-in board100. The connector420of the contact unit400is, for example, a pogo pin or a male/female connector. It is to be noted that depending on the measuring instrument300, a driver pin, an input-output (IO) pin, and a direct current (DC) measuring pin may be separated from each other, and therefore, the relay circuit410has a role of changing a signal path depending on, for example, whether passing a normal test signal or making a DC measurement.

FIG.2illustrates an example of a layout of the burn-in board100according to the embodiments. For simplicity of explanation,FIG.2illustrates a single SoC110and a single measuring instrument terminal120, corresponding to a single burn-in socket130.

As illustrated inFIG.2, all pins of the SoC110are exposed as a metallic terminal125on the substrate around the SoC110of the burn-in board100so that each pin of the SoC110can be electrically connected to the contact unit400. One metallic terminal125is arranged for one pin of the SoC110.

If the SoC110is only to be inspected for Voltage Forward (VF) or other contact inspection from outside the burn-in board100, only the signal pin among the pins of the SoC110may be used. However, when measuring a voltage on the signal pin of the SoC110, since it is necessary to activate the SoC110by applying an electric current between an electric power source and a ground (GND) of the SoC110, it is configured so that all pins, such as the power pin, GND pin, and signal pin, are exposed as metal terminal125. A short circuit between pins of the SoC110can also be detected by exposing all pins of the SoC110.

In the layout illustrated inFIG.2, a pin group143at the side of the burn-in terminal101is exposed from the substrate of the burn-in board100as a first metallic terminal group121, among all pins of the SoC110. Moreover, a pin group144at the side of the burn-in socket input/output terminal135is exposed from the substrate of the burn-in board100as a second metallic terminal group122, among all pins of the SoC110.

A wiring group141between the first metallic terminal group121and the burn-in terminal101, a wiring group142between the second metallic terminal group122and the burn-in socket input/output terminal135, and the pin groups143and144can be configured as wirings embedded in the substrate of the burn-in board100. Alternatively, the wiring group141, the wiring group142, and the pin groups143and144can also be configured as multi-layer wirings embedded in the substrate.

Each pin of the contact unit400is configured to be connectable to the electrical quantity measurement pin of the measuring instrument300by means of the relay circuit410of the contact unit400, details of which will be described below.

FIG.3illustrates another example of a layout of the burn-in board100according to the embodiments. For simplicity of explanation,FIG.3illustrates a single SoC110and a single measuring instrument terminal120, corresponding to a single burn-in socket130.

As illustrated inFIG.3, a measuring instrument terminal120from which a first metallic terminal group121connected to a pin group143at the side of a burn-in terminal101is exposed is arranged between the wiring group141between burn-in terminals101and the measuring instrument terminal and the SoC110, and a measuring instrument terminal120from which a second metallic terminal group122connected to a pin group144at the side of the burn-in terminal101is exposed is arranged between the wiring group142between the burn-in socket input/output terminals135and the measuring instrument terminal and the SoC110. The rest of the configurations of the layout example illustrated inFIG.3is the same as that of the layout example illustrated inFIG.2.

FIG.4illustrates an example of providing tri state buffers115_1,115_2, . . . ,115_nrespectively in SoC110_1,110_2, . . . ,110_nmounted on the burn-in board100according to the embodiments. In the example illustrated inFIG.4, for simplicity of explanation, a tri state buffer115is disposed corresponding to a single pin being provided in each SoC110, but the tri state buffer115is arranged for each of all pins of each SoC110.

All pins of the SoC110_1,110_2, . . . ,110_nhave respectively tri state buffers115_1,115_2, . . . ,115_n, and can control an output state of each pin from the control unit220in the burn-in apparatus200. More specifically, a control signal of the SoC110is connected to the control unit220in the burn-in apparatus200, and the tri state buffer115of the SoC110can be controlled to switch three output states, a high state, a low state, and a high impedance (HiZ) state by, for example, rewriting a control command, a register in the SoC110, or the like. By switching the tri state buffer115provided in a non-measuring target SoC110to the high impedance state, such a non-measuring target SoC110can be disconnected therefrom. Consequently, even if the pin is shared, the electrical quantity of only the measuring target SoCs110can be measured.

(Diagnostic Method of Test Board)

There will now be described a diagnostic method of the burn-in board100on which the SoC110is mounted, in the diagnostic system according to the embodiments.

A diagnostic method of the burn-in board100on which the SoC110is mounted in the diagnostic system according to the embodiments includes: connecting the burn-in board100to a burn-in apparatus200; supplying, by the burn-in apparatus200, electric power to the burn-in board100and controlling the SoC110by the burn-in apparatus; measuring, by a measuring instrument300, electrical characteristics of the SoC110; and mounting, on the burn-in board100, a contact unit400capable of electrically connecting the measuring instrument300to the SoC.

It is to be noted that the processing operations of the diagnostic method of the burn-in board100in the diagnostic system according to the embodiments can also be described in a computer program as instructions to be executed by computers.

FIG.5illustrates an example of a processing operation of the diagnostic method of the burn-in board100on which the SoC110is mounted, in the diagnostic system according to the embodiments.

In Step S101, the burn-in board100is connected to the burn-in apparatus200.

In Step S102, an SoC110to be test target (i.e., to be under test) among the SoCs110_1to110_nrespectively inserted into the burn-in socket input/output terminals135_1to135_nmounted on the burn-in board100is determined.

In Step S103, the contact unit400to which the measuring instrument300is connected is automatically or manually connected to the nearest measuring instrument terminal120of the test target SoC110(i.e., measuring instrument terminal120mounted corresponding to the test target SoC110). The connection of the contact unit400to the measuring instrument terminal120in Step S103means physically contacting the contact unit400connected to the measuring instrument300and the relay circuit410to the metallic terminal125of the measuring instrument terminal120on the burn-in board100. The connection means is not limited in particular to an automatic operation by devices, such as a robot arm, or a manual operation by human resources.

In the embodiments, it is necessary for diagnostics of the SoC110to diagnose performance of an input/output pin of the SoC110in addition to the functional diagnostics inside the SoC110. In particular, since the pin group144of the SoC110at the burn-in socket input/output terminal135side needs to have performance capable of high-speed testing, a pin output current is measured for determination of the performance diagnostics. Therefore, the connection of the measuring instrument is required for the performance diagnostics in the SoC110.

In the embodiments, executing a “high-speed test” means that a frequency of the signal is high and therefore the switching time between high level and low level of the signal is short. However, when the load is heavy, such as when the signal line is shared among a plurality of DUTs, a delay may occur in switching between high level and low level. In such a case, the next high-level/low-level switching timing comes before the high-level/low-level is switched, and as a result, the high-speed test cannot be executed. The load causing this factor includes a capacity component and a resistance component The resistance component thereamong is dominated by an output resistance of an output buffer in the SoC110, and measuring such a resistance value is used to determine whether or not the high-speed test can be executed. This resistance value can be calculated by apply a voltage to both ends of the resistance value and measuring an electric current which flows thereinto. Therefore, since the output resistance of the SoC110can be obtained by measuring the pin output current and then can be compared with the amount of load capable of executing the high-speed test (i.e., threshold value of diagnostics), thereby determining whether or not the high-speed test can be executed. Thus, a tester capable of high-speed IF connection is not necessary, since the measuring instrument300capable of DC measurement can determine whether or not the high-speed test can be executed.

In Step S104, electric power is supplied to the burn-in board100from the power supply unit210in the burn-in apparatus200.

In Step S105, the control unit220in the burn-in apparatus200selects a non-diagnostic target SoC110of the SoCs110being mounted on the burn-in board100.

In Step S106, the control unit220controls the share pin of the non-diagnostic target SoC110to shift to the HiZ state in order to disconnect the non-diagnostic target SoC110from the SoC group in which the control and data lines are shared. The shared lines of the burn-in board100are wired in two types, row and column, as the example illustrated inFIG.6. Then, it is possible to control the diagnostic target SoC110(e.g., SoC2in the example inFIG.6) by selecting rows and columns in accordance with a processing matrix illustrated toFIG.7. In the example illustrated inFIG.7, for example, when selecting the SoC2, only the diagnostic target SoC2can be selected by switching non-diagnostic target SoCs110(e.g., SoC1and SoC3to SoC15) except for the SoC2, a combination of the row selection1and the column selection2, to the HiZ state. It is to be noted that the selection order of the non-diagnostic target SoCs110does not matter for the processing matrix illustrated inFIG.7. When newly switching to a diagnostic target SoC, the high impedance (HiZ) state can be canceled by turning off the electric power to the SoC110.

In Step S107, the control unit220determines whether or not there are still any non-diagnostic target SoCs110remaining. As a result of determination of Step S107, if there are still non-diagnostic target SoCs110remaining, it returns to Step S105and executes the processes in steps S105to S106with respect to the remaining non-diagnostic target SoC110.

As a result of determination of Step S107, if there are no remaining non-diagnostic target SoC110(i.e., when all shared pins of the non-diagnostic target SoC is set to HiZ), it proceeds to Step S108.

In Step S108, a diagnostic target SoC110is selected in order to execute the diagnostics for the diagnostic target SoC110.

In step S109, the relay circuit410of the contact unit400is used to connect the measurement pins of the measuring instrument300to the share pins of the diagnostic target SoC110. In Step S110, the measuring instrument300measures an electrical quantity of only the shared line pin of the diagnostic target SoC110.

FIG.8illustrates an example of diagnosing the performance of the burn-in terminal101-side pin of the SoC110_1by selecting a specific SoC110_1from the group of the SoCs110_1to110_3in which the control and data lines are shared, in the diagnostic system according to the embodiments. In the example illustrated inFIG.8, the tri state buffers115_2to115_3of the non-diagnostic target SoCs110_2to110_3are each in the high impedance state, and the electrical quantity of only the shared line pins of the diagnostic target SoC110_1, where the tri state buffer115_1is in the high/low state, is measured by the measuring instrument300.

Even if trying to measure the electrical quantity of the shared line pin of the diagnostic target SoC110_1, without excluding the non-diagnostic target SoCs110_2to110_3, it is not possible to accurately measure the electrical quantity of only the shared line pin of the SoC110_1. In contrast, in the example illustrated inFIG.8, the electrical quantity of only the shared line pin of the diagnostic target SoC110_1can be accurately measured, with excluding the non-diagnostic target SoCs110_2to110_3.

Returning toFIG.5, it is determined in Step S111whether or not any of the measuring target pins still remain among the pins of the diagnostic target SoC110. As a result of the determination of Step S111, if there are still measuring target pins remaining, it returns to Step S109and executes the processes in Steps S109to S110with respect to the remaining measuring target pin.

As a result of the determination of Step S111, if there are no measuring target pin remaining, it proceeds to Step S112.

In Step S112, the electric power supply from the power supply unit210in the burn-in apparatus200to the burn-in board100is stopped.

In Step S113, the connected contact unit400to which the measuring instrument300is connected is automatically or manually disconnected from the measuring instrument terminal120of the test target SoC110.

In Step S114, the control unit220determines whether or not there are still any non-diagnostic target SoCs110remaining. As a result of determination of Step S114, if there are still non-diagnostic target SoCs110remaining, it returns to Step S102and executes the processes in Steps S102to S113with respect to the remaining non-diagnostic target SoC110.

As a result of the determination of Step S114, if there are no non-diagnostic target SoCs remaining, it proceeds to Step S115.

In Step S115, the burn-in board100is disconnected from the burn-in apparatus200.

FIG.9illustrates a processing operation example of measuring an electrical quantity of a burn-in socket130-side pin of the SoC110, in the diagnostic system according to the embodiments.

For the pin of the SoC110connected to the burn-in socket130, the electrical quantity can be measured from the contact unit400by using the same processing operation as those illustrated inFIGS.5to7.

Even if trying to measure the electrical quantity of the burn-in socket130-side pins of the SoC110from the burn-in apparatus200side through the burn-in terminal, for example, without arranging the measuring instrument terminal120for connecting the contact unit400between the SoC110and the burn-in socket130, it is difficult to execute measurement between the SoC110and the burn-in socket130, which operate at high speed. More specifically, since even if trying to measure, from the burn-in apparatus200side, the electrical quantity of the burn-in socket130-side pin of the SoC110, the contact resistance of the burn-in socket130is also included in the measured value, it is impossible to inspect performance degradation degree of the SoC110itself.

In contrast, in the example illustrated inFIG.9, since the measuring instrument terminal120for connecting the contact unit400between the SoC110and the burn-in socket130is arranged similarly to the layout example illustrated inFIG.3, it is possible to accurately measure the electrical quantity of only the SoC110.

In addition, the second metallic terminal group122in the measuring instrument terminal120, as in the example layout illustrated inFIG.2, can be used to accurately measure the electrical quantity of only the SoC110in the same way.

Contact Configuration Example Between Contact Unit and Measuring Instrument Terminal

FIG.10illustrates an example of a contact configuration between the contact unit400and the measuring instrument terminal120, in the diagnostic system according to the embodiments.

In the example illustrated inFIG.10, the connector420portion of the contact unit400is constituted of a spring-loaded pin connector421, and the measuring instrument terminal120is constituted of a pin pad123. The spring-loaded pin type contact structure includes, for example, a pogo contact structure. The pogo contact structure is generally a three-piece pogo pine structure, having a spring between two pins, and three-piece parts are all metal capable of being connected to be energized.

By adopting the spring-loaded pin type contact structure into the contact configuration between the contact unit400and the measuring instrument terminal120, it is possible to connect the contact unit400to the measuring instrument terminal120only during the diagnostics of the burn-in board. Therefore, it is possible to remove a stub and a capacitive load, which obstructs high-speed testing when executing a normal burn-in test. In other words, if a spring-loaded pin type contact structure is used to contact the electrical path between the SoC110and the burn-in socket130, the electrical path from the pin pad123, which is a metal terminal provided on the board of the burn-in board100, to the measuring instrument300side, it becomes a stub. In contrast, as illustrated inFIG.10, since the spring-loaded pin connector421of the contact unit400can be disconnected from the pin pad123of the measuring instrument terminal120, the signal quality is not affected when actually testing the burn-in socket130from the SoC110.

FIG.11illustrates another example of the contact configuration between the contact unit400and the measuring instrument terminal120, in the diagnostic system according to the embodiments. In the example illustrated inFIG.11, the connector420portion of the contact unit400is constituted of a male connector422, and the measuring instrument terminal120is constituted of a female connector124.

In the case of the spring-loaded pin-type contact structure illustrated inFIG.10, the contact thereof requires a high degree of accuracy, leading to increased costs for the diagnostic system.

In contrast, if the frequency of the high-speed test of the SoC110is low, it is also possible to adopt the connector connection structure that does not require relatively high contact accuracy by mounting connecting components, such as a connector, on the substrate of the burn-in board100, as illustrated inFIG.11.

Example of Parallel Operation of Burn-In Board Diagnostics

FIG.12illustrates an example of measuring in parallel an electrical quantity of the burn-in sockets130_1to130_2-side pins of a plurality of SoC110_1to SoC110_2, in the diagnostic system according to the embodiments.

In the example illustrated inFIG.12, a contact unit400_1to which a measuring instrument300_1is connected is connected to a measuring instrument terminal120_1corresponding to an SoC110_1, and an electrical quantity of a burn-in socket130_1-side pin of the SoC110_1is measured. Similarly, a contact unit400_2to which a measuring instrument300_2is connected is connected to a measuring instrument terminal120_2corresponding to an SoC110_2, and an electrical quantity of a burn-in socket130_2-side pin of the SoC110_2is measured. Consequently, the electrical quantity of each of the burn-in sockets130_1to130_2-side pins of the plurality of SoCs110_1to110_2can be measured in parallel.

When diagnosing a plurality of diagnostic target SoCs110_1to110_2by switching therebetween, it is conceivable that the test time will increase if the measurements are sequentially executed.

Therefore, as illustrated inFIG.12, the plurality of measuring instruments300_1to300_2, the plurality of contact units400_1to400_2, and the plurality of measuring instrument terminals120_1to120_2are prepared respectively, thereby increasing the number of burn-in boards100that can be diagnosed simultaneously. In particular, since the burn-in socket130-side pins of the SoCs110is connected one-to-one, it is suitable for parallel measurements.

Example of Diagnostics of Socket Contact

The diagnostic system according to the embodiments can also detect a degree of degradation of contact performance of the burn-in socket130mounted on the burn-in board100.

As illustrated inFIG.13, the contact performance of the burn-in socket130can be inspected by providing an electrode plate136which sets a signal pin137of the burn-in socket130to a specific electric potential. For example, the electrode plate136which short-circuits the signal pin137to the ground (GND) is inserted into the burn-in socket130, the target signal pin137is connected to the GND, and a voltage is applied from the measuring instrument300through the contact unit400, thereby measuring a flowing electric current. As a result, the contact resistance of the burn-in socket130can be calculated. For example, if the contact resistance at the side of the burn-in socket130is measured by burn-in board diagnostics periodically executed, a degree of aging degradation of the burn-in socket130can be inspected.FIG.13illustrates an example of the signal pin137that is a pogo pin.

Moreover, the diagnostic system according to the embodiments is capable of an initial test or mount check of the DUT. Furthermore, pass or failure of the DUT can be determined on the basis of test results of the DUT.

Specifically, as illustrated inFIG.13, the initial measurement and the mount check of the DUT mounted on the burn-in board100(e.g., test for verifying whether or not the DUT is inserted into the burn-in socket130) can also be executed from the measuring instrument300through the contact unit400.

For example, since there is no electrical connection path from the burn-in apparatus200side to the burn-in socket130even if trying to execute a mount check of the DUT through the burn-in terminal101from the burn-in apparatus200side, the check cannot be executed. Moreover, if performance diagnostics of the SoC110is executed without using the contact unit400and the measuring instrument300, it is also possible to execute a high-speed test for the SoC110from the burn-in socket130side. However, since the SoC110and the burn-in socket130are included in the diagnostic path, it is not possible to determine whether it is the SoC110or the burn-in socket130that is degrading performance when the test result is fail.

In contrast, according to the embodiments, since the measuring instrument300can be connected to the burn-in board100, it is possible to measure DC failure of the DUT and diagnose pass or failure of insertion of the DUT in a state of DUT being inserted into the burn-in socket130, before setting the burn-in board100in the burn-in apparatus200.

FIG.14illustrates an example of a relay circuit410provided in the contact unit400, in the diagnostic system according to the embodiments.

The relay circuit410is provided in the contact unit400. The relay circuit410is disposed immediately after the connector420, and therefore it is possible to switch a connection between a cable connected to the measuring instrument300and a side of the measuring instrument terminal120.

The relay circuit410can be controlled from the measuring instrument300side if the measuring instrument300is a tester or the like. However, even if it cannot be controlled from the measuring instrument300side, it can also be controlled through the burn-in board100from burn-in apparatus200when the measuring instrument terminal120is in contact with the contact unit400.

Effects Produced from the Embodiments

According to the embodiments, the following effects can be obtained.

It is possible to diagnose the SoC110mounted on the burn-in board100. Diagnostics of a plurality of SoCs110mounted on the burn-in board100can be executed sequentially and step by step.

In particular, it is configured so that the measuring instrument300capable of electrical inspection can be connected at an immediate vicinity of the SoC110on the substrate of the SoC-mounted burn-in board100, thereby accurately measuring the electrical quantity of only the SoC110by the measuring instrument300.

Moreover, it is configured to disconnect each SoC110electrically even if the control and data lines of a plurality of SoCs110are shared, the electrical quantity of the individual SoC110can be accurately measured, and the functions of the SoC110can be accurately diagnosed.

It is to be noted that the processing operations illustrated toFIG.5can also be described in a computer program as instructions to be executed by computers. The computer program is stored in, for example, a non-transitory computer-readable medium and is used for the diagnostic system according to the embodiments.

Moreover, the diagnostic system according to the embodiments may include an insertion and removal apparatus configured to insert/remove the DUTs respectively into/from the burn-in socket input/output terminals135of the burn-in socket130. The burn-in socket input/output terminals135can be connected to the insertion and removal apparatus configured to insert/remove the DUTs respectively into/from to the burn-in socket input/output terminal135.