JP2000039468A - Semiconductor testing apparatus and self-diagnostic method for semiconductor testing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a semiconductor testing apparatus by which information on a correction item to be corrected by performing a self-diagnosis and information on a failure unit are displayed and which can be helpful in a proper maintenance treatment. SOLUTION: In a self-diagnostic apparatus, data, for specification, which is required for spefifying a correction item and a failure unit on the basis of a diagnosed result is read out in Step S1, In Step S2, a self-diagnosis is executed regarding respective circuits which constitute a semiconductor testing apparatus. Its diagnosed result is stored (Step S3). Whether all diagnosed results are good or not is judged (Step S4). When even one item is defective, the existence of the correction item is judged on the basis of the data, for specification, which is read out previously (Step S5). In Step S6, a required correction item is corrected. When the diagnosed results are defective in Step S4 even after all necessary corrections, the failure unit is displayed in Step S7. Since the correction item and the failure unit are found, a maintenance operation can be performed easily on the basis of them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor tester for testing electrical characteristics of a semiconductor, and more particularly to an improvement of a semiconductor tester having a self-diagnosis function and a method of self-diagnosis of a semiconductor tester.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram showing a configuration of a conventional semiconductor test apparatus having a self-diagnosis function, and FIG. 10 is a block diagram showing a configuration of a self-correcting means. In the figure, reference numeral 13 denotes a test target device to be tested, and 1 denotes a central processing unit (hereinafter, referred to as a CPU), which configures a semiconductor test apparatus by executing a program describing test conditions, a test execution order, and the like. Data is set in each circuit to be performed, and output data from each measurement circuit is read based on the program.

Reference numeral 2 denotes a reference signal generation circuit for generating an operation reference signal, and reference numeral 3 denotes a waveform forming circuit for forming a test waveform (logic signal waveform) which changes in synchronization with the operation reference signal. The test waveform is for testing the device under test 13. Reference numeral 4 denotes a waveform output circuit, which has a self-correcting means 40 (details will be described later), amplifies a signal output from the waveform forming circuit 3 to a voltage value according to a test condition, and outputs the amplified signal to the device under test 13. Reference numeral 5 denotes a power supply voltage output circuit that outputs a power supply voltage of the device under test 13, and reference numeral 6 denotes a measurement power supply circuit that measures an output voltage value, an output current value, and the like from the device under test 13.

[0004] Reference numeral 7 denotes a relay circuit, which includes a circuit such as a waveform output circuit 4 and a power supply voltage output circuit 5 and a device under test 1.
3 and open. The waveform forming circuit 3 and the waveform output circuit 4 include a plurality of circuits having similar functions, and the device under test 13 having a plurality of terminals to be tested.
On the other hand, it is possible to output a test waveform under different conditions for each terminal.

[0005] By the way, a semiconductor test apparatus requires high measurement accuracy, but the operating characteristics such as the voltage, current, delay amount, etc. of elements inside the apparatus are changed due to changes in the surrounding environment such as temperature and power supply voltage. May change slightly and affect the measurement accuracy. For this reason, the circuits other than those of the waveform output circuit 4 are not shown, but each circuit is provided with self-correction means for calibrating this difference.

FIG. 10 shows the details of the self-correction means 40 of the waveform output circuit 4. In this example, the output voltage of the waveform output circuit 4 is corrected. The self-correcting means 40 includes a reference calibrator 21 which has been calibrated in advance by an external instrument and serves as a reference for calibration, an output voltage correcting means 41 (detailed configuration will be described later), and a voltage amplifying circuit 20 of the output voltage correcting means 41. A relay 22 is provided for connecting the reference calibrator 21 with the relay 22.

As shown in FIG. 10, the output voltage correction means 41 includes a data memory 16 for storing setting data from the CPU 1, a correction memory 17 for storing correction data, and a correction memory 17 for correcting the setting data in the data memory 16. It has an adder 18 for adding data, a D / A converter (DAC) 19 for converting digital information obtained by the adder 18 into analog information, and a voltage amplifying circuit 20 for amplifying a voltage obtained by the DAC 19. The CPU 1 reads the measured value of the reference calibrator 21 and reads the read value and the expected value,
That is, the difference from the set value from the CPU 1 is stored in the correction memory 17 as correction data.

Returning to FIG. 9, the self-diagnosis device 8 has a CPU
Upon receiving a command from the control unit 1, the self-diagnosis of the reference signal generation circuit 2, the waveform formation circuit 3, the waveform output circuit 4, and other circuits is periodically performed based on a self-diagnosis program stored in advance. Details of the operation will be described later.

The semiconductor test apparatus as described above has a CPU 1
Various tests are performed on the semiconductor device by setting various test conditions to the respective circuits via the data bus from the test program stored in the semiconductor device.

An example of the self-diagnosis of the waveform output circuit 4 by the self-diagnosis device 8 is a diagnosis for determining whether or not the output voltage value of the waveform output circuit 4 is normally output. When executing the diagnostic program, the device under test 1
No diagnostic relay 3 is provided, and during normal device testing, the diagnostic relay 14 that is disconnected is closed and the waveform output circuit 4 is connected to the measurement power supply circuit 6. The output signal from the waveform output circuit 4 is input to the measurement power supply circuit 6 via the relays 7 and 14, the voltage is measured, and the measured value is read by the self-diagnosis device 8 and compared with the expected value. The self-diagnosis device 8 determines whether the output voltage value of the waveform output circuit 4 is output normally or has failed, and outputs the result to a CRT (image display device) 15.

When a certain function of the semiconductor test device does not operate normally, the self-diagnosis device 8 displays a result of an error (“NG”) on the screen of the CRT 15 to notify the operator.
An operator who knows this manually performs correction of each related circuit. Thereafter, the diagnosis is performed again, and if an error still occurs, the maintenance is performed in a flow of determining that the unit is faulty and replacing the corresponding unit with a spare unit.

[0012]

When there is a defective part as a result of the self-diagnosis as described above, it is left to the maintenance operator to determine which part to correct. I was However, considerable experience is required to select an appropriate correction item or faulty unit from the diagnosis results displayed on the screen and perform quick maintenance processing. Judgment required a long time and was a heavy burden.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and outputs a correction item to be corrected and information on a faulty unit by performing a self-diagnosis, thereby assisting a proper maintenance process. The aim is to obtain a device. It is another object of the present invention to provide a method of self-diagnosis of a semiconductor test apparatus which can perform self-diagnosis to easily find a correction item or a faulty unit requiring correction.

[0014]

In order to achieve the above object, in a semiconductor test apparatus according to the present invention, self-diagnosis means for diagnosing a predetermined diagnosis item and storing the result of the diagnosis is provided. Correction item information storage means for storing information on correction items to be corrected when the diagnosis result is defective in association with the diagnosis item, which should be replaced when the diagnosis result on the diagnosis item is defective in advance Faulty unit information storage means for storing information on the faulty unit in association with the diagnosis item; correction item output means for outputting a correction item to be corrected based on the diagnosis result and the information on the correction item; A failure unit information output means for outputting information on a failure unit to be replaced based on the information is provided. The information of the correction item to be corrected when the diagnosis result of the diagnosis item is defective and the information of the failed unit to be replaced when the diagnosis result of the diagnosis item is defective are stored in advance. In addition, since a correction item to be corrected is output from the self-diagnosis result and information on a faulty unit to be replaced is output, a correction item to be corrected and a faulty unit to be replaced can be immediately known.

An automatic correction means is provided for automatically correcting a correction item to be corrected based on the output of the correction item output means. If the correction is performed automatically, labor can be saved.

Further, in the self-diagnosis method of the semiconductor test apparatus according to the present invention, self-diagnosis is performed for a predetermined diagnosis item, and information on a correction item to be corrected based on the diagnosis result and a faulty unit to be replaced are determined. Get information. Obtain information on correction items to be corrected and information on faulty units to be replaced from the self-diagnosis results, and immediately know the correction items to be corrected and faulty units to be replaced, to help perform appropriate maintenance measures be able to.

In addition, an automatic correction step for automatically correcting a correction item to be corrected based on a diagnosis result is provided, and after the correction is performed, a self-diagnosis is performed again on the diagnosis item to determine a faulty unit to be replaced. The information is output. If the automatic correction is performed, the diagnosis result may be good. Therefore, the automatic correction is performed first, and then the self-diagnosis is performed and the information of the failed unit is output.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 1 to 8 show an embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of a semiconductor test apparatus, FIG. 2 is a block diagram showing a detailed configuration of an automatic correcting means, and FIG. FIG. 3 is a block diagram illustrating a detailed configuration of the self-diagnosis device. FIG. 4 is a flowchart showing the operation of the self-diagnosis device. FIG. 5 is a matrix diagram showing the correspondence between diagnosis items and correction items, FIG. 6 is a matrix diagram showing the correspondence between diagnosis items and defective units, FIG.
FIG. 8 is a diagram illustrating an example of a diagnosis result.

In these figures, reference numeral 13 denotes a test target device to be tested, and 1 denotes a CPU, which executes a program describing test conditions, a test execution order, and the like, to transmit data to each circuit of the semiconductor test apparatus. It sets or reads output data from each measurement circuit based on the above program. Reference numeral 2 denotes a reference signal generating circuit that generates a test operation reference signal, and reference numeral 3 denotes a waveform forming circuit that forms a test waveform (logic signal waveform) necessary for testing the device under test 13 that changes in synchronization with the reference signal. It is.

Reference numeral 4 denotes a device to be tested 1 which amplifies a signal output from the waveform forming circuit 3 to a voltage value corresponding to a test condition.
3 is a waveform output circuit that outputs the waveform to the output circuit 3. Reference numeral 5 denotes a power supply voltage output circuit that outputs a power supply voltage of the device under test 13, and reference numeral 6 denotes a measurement power supply circuit that measures an output voltage value, an output current value, and the like from the device under test 13.

7 is a waveform output circuit 4 and a power supply voltage output circuit 5
And the like, and a relay circuit for connecting and disconnecting each circuit and the device under test 13. The waveform forming circuit 3 and the waveform output circuit 4 include a plurality of circuits having similar functions.
It is possible to output a test waveform under different conditions for each terminal to a device under test having a plurality of terminals under test.

Although a semiconductor test apparatus requires high measurement accuracy, the operating characteristics such as the voltage, current, and delay amount of elements inside the apparatus are changed due to changes in the surrounding environment such as temperature and power supply voltage. May change slightly and affect the measurement accuracy. For this reason, in the embodiment of FIG. 1, each circuit for calibrating this difference is provided with an automatic correction means.

FIG. 2 shows the details of the automatic correction means 50 of the waveform output circuit 4. In this example, although details will be described later, self-correction of the output voltage and the like of the waveform output circuit 4 is automatically performed based on the diagnosis result of the self-diagnosis device 80. The automatic correction means 50 includes a reference calibrator 21 which has been calibrated in advance by an external instrument and serves as a reference for calibration, and an output voltage correction means 4
1. A relay 52 for connecting the voltage amplifying circuit 20 of the output voltage correcting means 41 to the reference calibrator 21 is provided.

The output voltage correction means 41 includes a data memory 16 for storing setting data from the CPU 1, a correction memory 17 for storing correction data, and an adder 1 for adding the correction data of the correction memory 17 to the setting data of the data memory 16.
8. D / A converter (DAC) 1 for converting digital information obtained by adder 18 into analog information
9, a voltage amplifying circuit 20 for amplifying a voltage obtained by the DAC 19; The CPU 1 reads the measurement value of the reference calibrator 21 and stores the difference between the read value and the expected value, that is, the difference between the set value from the CPU 1 in the correction memory 17 as correction data.

The self-diagnosis device 80 receives a command from the CPU 1 and, based on a diagnosis item and a self-diagnosis program stored in advance, a reference signal generation circuit 2, a waveform formation circuit 3, a waveform output circuit 4, and other circuits. Perform self-diagnosis regularly. Then, a necessary correction item is determined based on the result, and the automatic correction unit 50 performs the automatic correction. Further, even if the correction is performed, the diagnosis result is not good (“N
G ") or those having no correction target item, that is, those having no relation to the correction, the related unit is displayed on the CRT 15 as a defective unit.

FIG. 3 shows a detailed configuration of the self-diagnosis device 80. In FIG. 3, reference numeral 31 denotes a self-diagnosis unit for self-diagnosis of a reference signal generation circuit 2, a waveform formation circuit 3, a waveform output circuit 4 and the like constituting a semiconductor test apparatus in accordance with a predetermined diagnosis program for predetermined diagnosis items. Is carried out. Reference numeral 32 denotes a diagnosis result storage unit that stores a determination result of each diagnosis item when a diagnosis is performed by the self-diagnosis unit 31 and a number of a failed unit. Reference numeral 33 denotes a correlation matrix storage unit that stores diagnosis items prepared for each circuit in advance and correction items related thereto. Numeral 34 denotes correction information storage means for storing information on correction items determined to require correction as a result of the self-diagnosis, and failure information 35 for storing information on failures as a result of the self-diagnosis, that is, information on faulty units determined to require replacement. It is storage means.

The correlation matrix storage means 33 is the correction item information storage means and the failure unit information storage means in the present invention, the correction information storage means 34 is the correction item output means in the present invention, and the defect information storage means 35 is the present invention. Is a failure unit information output means.

Next, referring to FIG. 4 to FIG.
Will be described. In step S1 of FIG. 4, for example, identification data necessary for identifying a correction item or a failed unit is read from the diagnosis results as shown in FIGS.

FIG. 5 shows an example of the specifying data. Correction should be made when each diagnosis item (leftmost column) of the waveform output circuit 4 (FIG. 1) and the result is an error ("NG"). FIG. 9 is a matrix diagram showing a relationship with a correction item, which is obtained in advance by analysis. This is stored in the correlation matrix storage means 33. In this example, the waveform output circuit 4
There are eight types of diagnostic items of H, and among the diagnostic items A to H, diagnostic items having related correction items are “waveform output circuit diagnosis C” and “H”, for example, “waveform output circuit diagnosis C”. Indicates that the waveform output circuit 4 should be corrected when the diagnosis result is "NG".

The other diagnostic items indicate that even if the diagnostic result is an error, it has no relation to the correction of the waveform output circuit 4. A diagnostic item that needs to be corrected when the diagnostic result is an error is, for example, a diagnostic that checks the accuracy of the output voltage, and is indispensable for performing highly accurate measurement.

FIG. 6 shows the diagnostic items (left end column) of the waveform output circuit 4 and the units UNIT1 and UNIT associated with the waveform output circuit 4 when the result is an error "NG".
2,... Are matrix diagrams showing identification data indicating a relationship with the failure of UNITn, which is obtained in advance by analysis. When the diagnosis result of each diagnosis item is an error, for example, when there is a correction item (in this case, correction of the waveform output circuit 4) as shown in “Waveform output circuit diagnosis C” in FIG. Is corrected and the unit UNIT2 is set to "NG" when an error still occurs after re-diagnosis.
There is a case in which there is no correction item such as “waveform output circuit diagnosis G” in FIG. 6 and the unit UNIT1 is immediately determined to be defective (FIG. 6).

Returning to the flowchart of FIG. 4, in step S2, the self-diagnosis means 31 performs diagnostic items for the reference signal generating circuit 2, the waveform forming circuit 3, the waveform output circuit 4, etc. The output circuit 4 performs a self-diagnosis for each diagnosis item in the left column of FIG. In step S3, the diagnosis result is stored in the diagnosis result storage means 32 as good ("GO") or error "NG" for each diagnosis item.

In step S4, it is determined whether or not all the diagnostic results are good. If at least one item is in error, the contents of the diagnostic result storage means 32 previously stored in step S5 are determined by the correlation matrix storage means 33. The necessary correction items are determined in comparison with the specific data
The correction information is stored in the correction information storage unit 34.

For example, when the diagnostic result as shown in FIG. 7 is stored in the diagnostic result storage means 32, among the diagnostic items of “NG”, “correlation matrix of FIG. It can be seen from the above that the diagnostic item related to the correction, that is, the diagnostic item that may become “GO” when corrected, is only “waveform output circuit C”. As a result, information as shown in FIG. 8 is output for the correction item.

Further, from the matrix information which is the specifying data relating to the faulty unit in FIG. 6 stored in the correlation matrix storage means 33, the unit involved in the diagnosis item "NG" of the waveform output circuit diagnosis C is unit UNIT
2. Since it is understood that the unit is UNIT4 (UNIT4 is omitted in the figure), the self-diagnosis unit 31 determines the diagnostic result "NG" of the diagnostic item "waveform output circuit diagnostic C" as shown in FIG.
, It is determined that the error units are UNIT2 and UNIT4. In addition, this unit UNIT2, UN
IT4 is also related to the correction item as described above.

Similarly, the diagnosis item "waveform output circuit diagnosis D"
Error unit corresponding to the diagnosis result "NG"
T1,2, diagnosis result "NG" of "waveform output circuit diagnosis G"
Error units correspond to UNITs 1, 3, and 4 (FIG. 6)
Then, the units UNIT3 and 4 are not shown.)
Is determined to be. This determination result is as shown in FIG.

If it is determined in step S5 that there is a correction item, in step S6 the self-diagnosis means 3
1 issues a command to the automatic correction means 50 (FIG. 2) and
2 is closed, the output from the voltage amplifier 20 is measured by the reference calibrator 21, and the difference between the measured value and the command value (the value that should be output) from the self-diagnosis means 31 is stored in the correction memory 17 as correction data. Automatically perform the work to be done.

After the automatic correction, the self-diagnosis means 31 performs the diagnostic item "waveform output circuit diagnosis C" again.
If the result is good in step S5, the judgment of the error units 2 and 4 stored in the fault information storage means 35 is canceled.
4 indicates that it is a failed unit. in this way,
The reason why the correction item is corrected prior to the replacement of the failed unit is that even if the diagnosis result is an error, it may be better by the correction.

When it is determined that the units 1 and 2 are defective based on the diagnosis result of the "waveform output circuit diagnosis D" in FIG. 7, the diagnosis error information stored in the diagnosis result storage means 32 as shown in FIG. Since there is no correction item related to (1), no correction is performed, and UNITs 1 and 2 are immediately displayed on the CRT 15 as failed units. The operator only needs to replace the failed units UNIT1 and UNIT2 while seeing this display, which eliminates the need for work requiring knowledge and experience, such as determining the failed unit from the diagnosis result.

As described above, the correction item and the faulty unit to be corrected are determined from the diagnosis result, the correction is automatically performed, and even if the correction is performed, the diagnosis result is not good. And for those without correction items, the relevant unit is displayed as a failed unit,
The unit to be replaced is immediately known. Therefore, appropriate treatment can be performed quickly and easily, and appropriate maintenance treatment can be easily performed even for an inexperienced person.

It should be noted that, without automatically correcting the correction items based on the diagnosis result, the diagnosis result as shown in FIG. 8 is displayed on the CRT 15, and the operator performs the correction and the replacement work of the faulty unit according to the result. Guidance may be provided.

[0042]

Since the present invention is configured as described above, it has the following effects. That is, in the semiconductor test apparatus of the present invention, self-diagnosis means for diagnosing a predetermined diagnosis item and storing the diagnosis result, a correction to be corrected when the diagnosis result for the diagnosis item is defective in advance Correction item information storage means for storing item information in association with a diagnosis item, and a failure unit for storing information on a failure unit to be replaced when a diagnosis result for the diagnosis item is defective in advance in association with the diagnosis item Information storage means, a correction item output means for outputting a correction item to be corrected based on the diagnosis result and the information on the correction item, and a fault for outputting information on the faulty unit to be replaced based on the diagnosis result and the information on the faulty unit Since the unit information output means is provided, information on the correction item to be corrected when the diagnosis result of the diagnosis item is defective is provided. And information on the faulty unit to be replaced when the diagnosis result of the diagnosis item is defective, and outputs a correction item to be corrected from the self-diagnosis result, and replaces it. Since the information of the faulty unit to be output is output, it is possible to immediately know the correction item to be corrected and the faulty unit to be replaced, and to assist in performing an appropriate maintenance process.

Since the automatic correction means for automatically correcting the correction item to be corrected based on the output of the correction item output means is provided, the correction is automatically performed, and labor is saved. And quick recovery.

Further, in the self-diagnosis method for a semiconductor test apparatus according to the present invention, self-diagnosis is performed on a predetermined diagnosis item, and information on a correction item to be corrected based on the diagnosis result and a faulty unit to be replaced are determined. Since the information is obtained, it is possible to immediately know the correction item to be corrected and the faulty unit to be replaced, and to assist in performing an appropriate maintenance process.

In addition, an automatic correction step for automatically correcting a correction item to be corrected based on the diagnosis result is provided, and after the correction, the self-diagnosis is performed again on the diagnosis item to determine a faulty unit to be replaced. Since the information is output, there is no possibility that the one that is good if the correction is made will not be a failure, and the information of the failed unit that needs to be replaced can be reliably obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a semiconductor test apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a detailed configuration of an automatic correction unit in FIG. 1;

FIG. 3 is a block diagram showing a detailed configuration of the self-diagnosis device of FIG.

FIG. 4 is a flowchart showing the operation of the self-diagnosis device of FIG.

FIG. 5 is a matrix diagram showing the correspondence between diagnostic items and correction items.

FIG. 6 is a matrix diagram showing the correspondence between diagnostic items and defective units.

FIG. 7 is a diagram showing an example of a diagnosis result.

FIG. 8 is a diagram illustrating an example of a diagnosis result.

FIG. 9 is a block diagram illustrating a configuration of a conventional semiconductor test apparatus.

FIG. 10 is a block diagram showing a configuration of a conventional self-correction unit.

[Explanation of symbols]

1 CPU, 4 waveform output circuits, 15 CRT, 31
Self-diagnosis circuit, 32 diagnosis result storage means, 33 correlation matrix storage means, 34 correction information storage means, 35 failure information storage means, 41 output voltage correction means, 50 automatic correction means, 52 relay, 80 self-diagnosis device.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G032 AC03 AE09 AE12 AE14 AG01 AH03 AK19 AL14 4M106 AA04 BA14 DH01 DH16 DJ12 DJ19 DJ21 DJ39

Claims (4)

[Claims] A self-diagnosis means for diagnosing a predetermined diagnosis item and storing the result of the diagnosis; and information on a correction item to be corrected when the diagnosis result of the diagnosis item is defective is determined in advance. Correction item information storage means for storing in correspondence with the diagnosis item, failure unit information storage for storing in advance the information of the failure unit to be replaced when the diagnosis result of the diagnosis item is defective in association with the diagnosis item Means, a correction item output means for outputting a correction item to be corrected based on the diagnosis result and the information on the correction item, and information on a faulty unit to be replaced based on the diagnosis result and the information on the faulty unit. A semiconductor test apparatus provided with faulty unit information output means. 2. The semiconductor test apparatus according to claim 1, further comprising automatic correction means for automatically correcting a correction item to be corrected based on an output of the correction item output means. 3. A self-diagnosis method for a semiconductor test apparatus, which performs a self-diagnosis on a predetermined diagnosis item and obtains information on a correction item to be corrected and information on a faulty unit to be replaced based on the diagnosis result. 4. An automatic correction step for automatically correcting a correction item to be corrected based on a diagnosis result, and performing a self-diagnosis again on the diagnosis item after the correction is performed to determine a faulty unit to be replaced. 4. The method according to claim 3, wherein the information is output.