JP2002340979A - Method of operating measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discover the nonconformity of a testing program and the fault of the communication system, etc., between a tester and a probe or handler in early stages. SOLUTION: Whether a plurality of semiconductor chips formed in a semiconductor wafer is normal or defective is discriminated by performing electrical measurement by successively bringing a probe card into contact with the chips. When a set number or more of continuous chips is discriminated as normal, a measuring instrument is tested. It is preferable to test the instrument by performing electrical measurement by bringing the probe card into contact with an effective area in the wafer except the semiconductor chips or without bringing the probe card into contact with the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of operating a measuring device for measuring electrical characteristics of a semiconductor chip formed in a semiconductor wafer or a semiconductor device in which individual semiconductor chips are packaged.

[0002]

2. Description of the Related Art For example, a measuring device used for testing a semiconductor chip in a state of a semiconductor wafer (wafer probe test) includes a probe card having a plurality of probe needles corresponding to the number of electrodes of the semiconductor chip; A tester that transmits and receives electrical signals to and from the semiconductor chip via this probe card and measures the electrical characteristics of the semiconductor chip, transports the semiconductor wafer, contacts the probe needles of the probe card with the electrodes of the semiconductor chip, and uses the tester And a prober for marking a defective semiconductor chip based on the measurement result.

When performing a wafer probe test,
In accordance with the instructions of the tester, the prober accurately aligns and contacts the electrodes of the semiconductor chip to be measured with the probe needles of the probe card. The tester transmits a test signal to the semiconductor chip according to the test pattern via the probe card, and the semiconductor chip operates according to the test signal. Then, the output signal of the semiconductor chip is received by the tester via the probe card, and its electrical characteristics are measured.

In a tester, an output signal of a semiconductor chip is compared with an expected output value of a test pattern, and the test result (pass (good) or fail (bad)) is transmitted to a prober. The prober marks the defective semiconductor chip with a marker based on the test result, and totalizes the data of the measurement result. In the measuring device, the above-described operation is continuously and automatically performed for each of the plurality of semiconductor chips formed on the semiconductor wafer.

[0005] Incidentally, the prober usually has a function of automatically stopping when a measurement result by the tester fails continuously for a certain number or more (defective). However, conversely, when the measurement result is always a pass (good), there is no function for verifying that the determination result is correct. Therefore, even if the measurement result always passes due to an abnormality in the measurement device such as a defect in the program for the wafer probe or a failure in the communication system with the tester during the automatic operation, it is not possible to determine whether the determination result is correct. It is possible.

The wafer probe test is an important step of judging the quality of each of a plurality of semiconductor chips formed on a semiconductor wafer based on the state of the semiconductor wafer.
As a result, package assembly and a final test of the defective semiconductor chip can be prevented. Therefore, if the measurement result is always determined to be a pass due to some problem, there is a problem that a defective semiconductor chip flows out to a subsequent process, which greatly affects package assembly and test costs.

In addition, semiconductor devices in which respective semiconductor chips are packaged are sequentially mounted in IC sockets (sockets for mounting ICs (semiconductor devices)), and electrical measurements are made. In the final test that determines whether the measurement result is always pass, the failure of the measuring device occurs due to the failure of the final test program or the failure of the communication system between the tester and the handler. There is a problem that the semiconductor device of this kind leaks to the market.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art and to quickly solve the problem of a test program and the failure of a communication system between a tester and a prober or a handler. An object of the present invention is to provide a method of operating a measuring device that can be found.

[0009]

In order to achieve the above object, the present invention provides an electric measurement by sequentially contacting a probe card with each of a plurality of semiconductor chips formed in a semiconductor wafer, A method of operating a measuring device for determining good or bad of each of the plurality of semiconductor chips,
It is an object of the present invention to provide a method of operating a measuring device, wherein a test of the measuring device is performed when a continuous good judgment equal to or more than a set number is obtained.

Here, the test of the measuring device is performed by bringing the probe card into contact with a region other than an effective semiconductor chip in the semiconductor wafer, or in a state where the probe card is not in contact with the semiconductor wafer. Preferably, it is performed by performing an electrical measurement.

The present invention also provides a method of operating a measuring device for sequentially mounting semiconductor devices sealed in a package into an IC socket and performing electrical measurements to determine whether each of the semiconductor devices is good or bad. A method of operating a measuring device, characterized in that a test of the measuring device is performed when a continuous good judgment equal to or greater than a set number is obtained.

Here, it is preferable that the test of the measuring device is performed by performing the electrical measurement in a state where the semiconductor device is not mounted on the IC socket.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for operating a measuring apparatus according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is a schematic view showing the configuration of an embodiment of a measuring apparatus to which the present invention is applied. The measuring device 10 shown in FIG.
The probe card 18 is sequentially brought into contact with each of the plurality of semiconductor chips formed on the semiconductor wafer to perform an electrical measurement.
It is used at the time of a probe test for determining a defect, and includes a wafer prober 12, a test head 14, and a test station (tester main body) 16.

Here, the wafer prober 12 has a wafer stage (not shown) for mounting a semiconductor wafer therein. With this wafer stage, the semiconductor wafer can be moved in each of the XYZ directions as shown in FIG. A probe card 1 having a plurality of probe needles (needles that contact the electrodes of the semiconductor chip) corresponding to the respective electrodes of the semiconductor chip is provided on the head plate of the wafer prober 12 (the upper surface of the body of the wafer prober 12).
8 is attached (fixed).

The wafer prober 12 has a tester IF.
(Interface) or GP-IB (General Purpos
e Interface Bus) is connected to the test station 16 via an interface such as e. Wafer prober 1
The test head 14 of the tester is mounted on the second head plate. One terminal of the test head 14 is connected to the probe card 18 and the other terminal is connected to the test station 16 via a test head cable.

The wafer prober 12 continuously connects a probe needle of a probe card to a plurality of semiconductor chips formed on a semiconductor wafer in accordance with an instruction of a test station 16 provided through an interface such as a tester IF or GP-IB. Contact sequentially.

At this time, in the wafer prober 12, the semiconductor wafer to be measured is automatically transferred and placed on a wafer stage (not shown). In the wafer prober 12, information on the semiconductor wafer and the semiconductor chip to be measured and information on the probe card 18 are stored in advance as parameters for each type. As a result, the wafer stage is moved in each of the X, Y, and Z directions, and the electrodes of the semiconductor chip to be measured and the probe needles of the probe card 18 are positioned and contacted with high accuracy.

As described above, the test station 16 gives an instruction to the wafer prober 12, and transmits a test signal to the semiconductor chip according to a test pattern via the test head cable, the test head 14, and the probe card 18. The semiconductor chip operates in response to the test signal, and the output signal is also received by the test station 16 via the probe card 18, the test head 14, and the test head cable, and its electrical characteristics are measured.

The test station 16 compares the output signal of the semiconductor chip with the expected output value of the test pattern, and outputs the test result (pass (good) or fail) via an interface such as a tester IF or GP-IB. (Defective)) to the wafer prober 12. The wafer prober 12 marks the defective semiconductor chip with a marker (not shown) based on the test result, and totalizes the data of the measurement result.

Here, the wafer prober 12 has a counter (not shown) for counting a test result (pass or fail) transmitted from the test station 16. The counter counts the number of semiconductor chips that have passed the test continuously, and when the number of continuous good judgments equal to or greater than the set number is obtained, the test of the measuring device 10 is performed. The set number is set in advance in, for example, parameters for each product type. A similar counter can be provided at the test station 16.

At this time, the test of the measuring apparatus 10 is performed by using the same test pattern (test program) used for measuring the electrical characteristics of the semiconductor chip to be measured, as described above. The probe card 18 is brought into contact with a region other than the valid semiconductor chip, for example, on the invalid semiconductor chip around the semiconductor wafer, or by performing an electrical measurement in a state where the probe card 18 is not in contact with the semiconductor wafer. It is preferred to carry out.

Here, if the test result is failed,
There is no problem in the test program, the communication system between the wafer prober 12 and the test station 16, and the like. That is, since it can be determined that the measurement device 10 is normal, the measurement of the semiconductor chip is resumed after the interruption. On the other hand, if the test result passes, it can be determined that there is an abnormality in the measuring apparatus 10, so that the wafer prober 12 generates an error and stops its operation.

When continuous good judgments are obtained,
The set number of the counter for performing the test of the measuring apparatus 10 is preferably determined as appropriate from past results and experimental data based on, for example, the type of device, the type of manufacturing process, the die size of the semiconductor chip, and the like. . In the above-described embodiment, an example in which the present invention is applied to a probe test has been described. However, the present invention is not limited to this. For example, the present invention can be applied to a final test.

FIG. 2 is a conceptual diagram showing the configuration of another embodiment of the measuring apparatus to which the present invention is applied. Measurement device 20 shown in FIG.
The semiconductor device 30 is mounted in the IC socket (socket for mounting an IC (semiconductor device)) 32 in order, and the electrical measurement is performed.
The handler 22 and the test head 24 are used at the time of a final test for judging good or bad.
And a test station (tester main body) 26.

Here, the handler 22 has a device transport section 28 for sucking and transporting the semiconductor device (device) 32. The device transport unit 28 is movable in the vertical direction as shown in FIG. The test head 24 is disposed directly below the device transport section 28 of the handler 22. The head plate of the test head 24 has an IC socket having a number of pin grooves corresponding to each pin (terminal) of the semiconductor device 32. 32 is attached (fixed).

The handler 22 is connected to a test station 26 via an interface such as a tester IF (interface). On the other hand, the test head 14
Each terminal of the IC socket 32 attached to the test station 26 is connected to the test station 26 via a test head cable.

The handler 22 removes the packaged semiconductor device 30 from the package according to the instruction of the test station 26 given through an interface such as a tester IF.
It is sequentially and sequentially mounted on the C socket 32.

At this time, in the handler 22, the semiconductor device 30 to be measured is automatically conveyed and mounted on the IC socket 32. In the handler 22, information on the semiconductor device to be measured and information on the IC socket 32 are stored in advance as parameters for each type. As a result, the device transport section 28 is moved, the pins of the semiconductor device 30 to be measured and the pin grooves of the IC socket 32 are aligned with high precision, and the semiconductor device 30 is mounted on the IC socket 32.

The operation thereafter is that the wafer prober 12 is the handler 22, the test head 14 and the test station 16 are the test head 24 and the test station 26, respectively, and the probe card 18 is the IC socket 32. Except for the point and the point that the semiconductor wafer is the semiconductor device 30, it is completely the same as the case of the measuring device 10 for the wafer probe test shown in FIG. 1, and the detailed description thereof is omitted.

That is, a test signal is transmitted from the test station 26 to the semiconductor device 30, and an output signal of the semiconductor device 30 operated in response thereto is received by the test station 26, and its electrical characteristics are measured. Also,
The test station 26 compares the output signal of the semiconductor device 30 with the expected output value of the test pattern to determine whether the semiconductor device 30 is good or bad. On the basis of the test results, the handler 22 stores the measured semiconductor device 30 in a magazine (not shown) for each of a good product and a defective product.

Here, the handler 22 has a counter for instructing the execution of the test of the measuring device 20 when the number of continuous good judgments equal to or more than the set number is obtained, or a similar counter is provided in the test station 26. It is also possible. At this time, the test of the measuring device 20 is performed by using the same test pattern (test program) used when measuring the electrical characteristics of the semiconductor device 30 to be measured, by attaching the semiconductor device 30 to the IC socket 32 without mounting. It is preferred to carry out the electrical measurement in the state.

The operating method of the measuring device according to the present invention is basically as described above. As described above, the operation method of the measuring device of the present invention has been described in detail. However, the present invention is not limited to the above embodiment, and various improvements and changes may be made without departing from the gist of the present invention. Of course.

[0034]

As described above in detail, the operating method of the measuring apparatus according to the present invention performs electrical measurement by sequentially contacting a probe card with each of a plurality of semiconductor chips formed in a semiconductor wafer. In order to judge whether each semiconductor device is good or bad, determine whether each semiconductor device is good or bad, or mount the packaged semiconductor devices sequentially in an IC socket and perform electrical measurement. If you get more than the set number of consecutive good judgments,
The test of the measuring device is performed. Thus, according to the operating method of the measuring device of the present invention, it is possible to early find a failure of the test program or a failure of the communication system between the tester and the prober or the handler, and to assemble the package relating to the defective product. In addition, the cost and test cost of the semiconductor device can be reduced, and the outflow of defective semiconductor devices to the market can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of a measuring apparatus to which the present invention is applied.

FIG. 2 is a conceptual diagram showing the configuration of another embodiment of the measuring apparatus to which the present invention is applied.

[Explanation of symbols]

 10, 20 Measuring apparatus 12 Wafer prober 14, 24 Test head 16, 26 Test station (tester main body) 18 Probe card 22 Handler 28 Device transport section 30 Semiconductor device 32 IC socket

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Claims (4)

[Claims] 1. A measuring apparatus for making electrical measurements by sequentially contacting a probe card with each of a plurality of semiconductor chips formed in a semiconductor wafer and determining whether each of the plurality of semiconductor chips is good or defective. A method of operating a measuring device, wherein a test of the measuring device is performed when a predetermined number or more of good judgments are obtained. 2. The test of the measuring device is performed by contacting the probe card with a region other than an effective semiconductor chip in the semiconductor wafer, or by performing the electric test while the probe card is not in contact with the semiconductor wafer. The method according to claim 1, wherein the method is performed by performing dynamic measurement. 3. A semiconductor device sealed in a package is
A method of operating a measuring device which is mounted on a C socket and performs electrical measurement to determine whether each of the semiconductor devices is good or bad. A method for operating a measuring apparatus, characterized by performing a test. 4. The operation of the measuring device according to claim 3, wherein the test of the measuring device is performed by performing the electrical measurement in a state where the semiconductor device is not mounted on the IC socket. Method.