JP3177981B2 - Wafer test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Regarding a wafer test apparatus, the purpose is to prevent damage to devices and loss time caused by setting a probe card that does not conform to a wafer, and to respond to various types of wafers to be tested. A wafer test apparatus for selectively setting the probe card and testing the characteristics of the wafer, wherein the probe card ID information attached to the probe card is read. A reading unit, a communication unit that sends the probe card ID information read by the reading unit to the tester, a holding unit that holds input information corresponding to a wafer to be tested and input in advance, and a reading unit that is read by the reading unit. Comparing means for comparing the probe card ID information with the input information held in the holding means, and a probe by the comparing means And a result output unit for outputting a comparison result indicating whether the input ID information matches or does not match the input information, wherein the reading unit includes an outlet of a probe card stocker storing a plurality of probe cards. Or, when the probe card is replaced while being mounted during the transfer of the probe card, the probe card ID information attached to the probe card is read, and the probe card ID information attached to the probe card and the test previously input are used. Only when the input information corresponding to the wafer to be matched matches, the characteristics of the wafer are tested based on the probe card ID information.

[Industrial applications]

The present invention relates to a wafer test apparatus, and more particularly, to a wafer test apparatus that tests a characteristic of a wafer by setting a probe card suitable for the wafer, for example, which is suitable for use in the field of wafer test.

In recent years, for example, in a semiconductor device using a wafer made of a silicon (Si) chip or the like, the density and capacity have been increased, and accordingly, the test time of the wafer has been prolonged, and the test time has been shortened. For this purpose, many wafer test apparatuses for testing the characteristics of a wafer using a measurement medium called a probe card have been developed.

In this method, a probe card suitable for a wafer is selectively set according to various wafers to be tested, and the characteristics of the wafer are tested. The probe card is determined corresponding to each wafer. Therefore, it is necessary to set a probe card suitable for the wafer.

[Conventional technology]

As a conventional wafer test apparatus of this type, for example, there is one as shown in FIG.

The prober 1, which is a wafer test apparatus, is roughly composed of a test circuit 2, a probe card 3, and a stage 4.

 Reference numeral 5 denotes a wafer.

As shown in FIG. 6, the probe card 3 is a disk-shaped measurement medium in which a hole 7 corresponding to the chip 6 formed on the wafer 5 is formed at the center, and the stage 4 is vertically, horizontally, and vertically. The probe 8 provided in the vicinity of the hole 7 is brought into contact with a predetermined I / O cell on the chip 6 of the wafer 5 as shown in FIG. This is for testing the characteristics of the wafer 5.

Reference numeral 9 denotes a label on which the name of the probe card 3 and the serial number are written, and reference numeral 10 denotes a label on which the name of the device of the wafer 5 and the like are written.

In the above configuration, when testing the characteristics of the wafer 5, the probe card 3 that matches the wafer 5 to be tested is manually selected, that is, the label 9 of the wafer 5 is selected.
The probe card 3 to which the label 10 conforming to the above is attached is set in the prober 1, and the test of the wafer 5 is performed.

[Problems to be solved by the invention]

However, in such a conventional wafer test apparatus, since a probe card suitable for a wafer is manually selected, a setting error of the probe card with respect to the prober easily occurs.

This is because there are many similar product names and serial numbers to the device names and serial numbers of the devices used for the labels 9 and 10. If the probe card 3 is incorrectly set, the wafer placed on the stage 4 In addition to the damage to the probe card 5, there is a problem that the loss time of the test time increases, for example, when the distance between the prober 1 and the probe card 3 is large due to space or other reasons.

Therefore, an object of the present invention is to prevent damage to devices and loss time caused by setting a probe card that does not match a wafer.

[Means for solving the problem]

The wafer test apparatus according to the present invention achieves the above object,
As shown in the principle diagram of FIG. 1, a measurement medium (probe card) 3 for measuring the wafer according to various kinds of wafers to be tested is provided. A wafer test apparatus 1 for testing characteristics of a wafer, wherein a probe card ID attached to the probe card 3 is provided.
A reading unit 11 for reading information, a communication unit (not shown) for sending the probe card ID information read by the reading unit 11 to a tester, and a holding unit for holding input information which is input in advance and corresponds to a wafer to be tested Means 12 and comparison means for comparing the probe card ID information read by the reading means 11 with the input information held in the holding means 12
13 and a result output unit 14 for outputting a comparison result indicating whether the probe card ID information and the input information by the comparison unit 13 match or mismatch with each other, and the reading unit 11 At the time of replacement, the probe card ID information attached to the probe card 3 is read, and only when the probe card ID information attached to the probe card matches the previously input information corresponding to the wafer to be tested. The configuration is such that the characteristics of the wafer are tested based on the probe card ID information.

[Action]

In the present invention, whether the input information and the read information match or mismatch is output by the result output unit, and only when the input information and the read information match, the characteristic of the wafer by the measurement medium is tested.

That is, a measurement medium that is not compatible with the wafer is not set in the wafer test apparatus.

Therefore, damage to the device due to the setting of a measurement medium that is not compatible with the wafer is prevented, and loss of test time is prevented.

〔Example〕

 Hereinafter, the present invention will be described with reference to the drawings.

FIG. 2 is a view showing one embodiment of a wafer test apparatus according to the present invention. In FIG. 2, the principle diagram shown in FIG.
The same numbers as those given to the conventional examples shown in FIGS. 5 to 7 indicate the same parts.

The wafer test apparatus 1 of the present embodiment is roughly divided into a barcode scanner 11 serving as a reading unit and a memory 1 serving as a holding unit.
2. It comprises a comparator 13 as comparison means, a display alarm 14 as result output means, a ring insert 15, and a keyboard 16.

17 is a probe card stocker, 18 is a tester, 19
Is the host CPU.

In the probe card 3 of this embodiment, an ID label using a 9-digit bar code called CODE39 as shown in FIG.

The ring insert 15 is used to set the probe card 3
Is held.

The keyboard 16 is for inputting information about the wafer 5 in advance. The contents of the ID information may be, for example, a probe card product name, a serial number, and the like. , A to Z, and a space (blank) are specified within eight characters, and if less than eight, a space (blank) is added at the end.

The probe card stocker 17 stores a plurality of probe cards 3 to which an ID label is attached, and transports the probe card 3 from the probe card stocker 17 to the ring insert 15 by a robot mechanism attached to the prober 1.

The barcode scanner 11 is attached to the outlet of the probe card stocker 17 while the probe card 3 is being conveyed or set in the ring insert 15,
The ID information of the probe card 3 is read.

The tester 18 runs a predetermined test program, and the host CPU 19 inputs information about the wafer 5 instead of the keyboard 16 by communication means or the like.

 Next, the operation will be described.

First, before the operation of the prober 1, prober parameters corresponding to the wafer 5 to be tested are set in advance. That is, the name and serial number of the probe card 3 stored in the probe card stocker 17 are notified to the prober 1 in advance.

The notification to the prober 1 is made when the stock number of the probe card 3 stored in the probe card stocker 17 is small, the input by the keyboard 16 or the movement input by the barcode scanner is performed.
Data from a pre-built database is used as the host CP
The data is transferred from U19 to the memory 12. As shown in Table 1, the information input to the memory 12 is a parameter corresponding to a stock #, for example, an item name,
A serial number or the like is selected.

Here, the probe card 3 is uniquely identified by the device name.
Is determined, the input item can be only the product name.

The information actually input from the keyboard 16 or the host CPU 19 is, for example, ASCII code of less than 8 characters, such as product name: H1234567 serial number: S1234567. Is decomposed into bit information and handled. And these 8
A checksum code is added to the ninth digit of the character string based on the 3of9 code checksum value shown in Table 1 below.

That is, for example, codes of D2C51I, D2C51A1 #, and D09B56AX1 are generated for the following probe card product names of D2C51, D2C51A1, and D09B56AX.

Therefore, in the case of the data of the above-mentioned product name: H1234567 serial number: S1234567, data as shown in Table 2 is stored in the memory 12.

 Note that x and y in Table 2 indicate checksum codes.

Next, the ID label of the probe card 3 conveyed from the probe card stocker 17 is read by the barcode scanner 11, and the read information is temporarily stored in a memory in the barcode scanner 11.

Here, the memory in the barcode scanner 11 has the third
It is assumed that data as shown in the table is stored.

 Note that x and z in Table 3 indicate checksum codes.

In the comparator 13, the memory 12 is compared with the read information, and the prober 1 is controlled based on the result.

That is, first, the address add1 of the memory 12 is compared with the address add3 of the memory in the barcode scanner 11, and the data of the address add1 and the data of the address add3 are the same. The data is compared.

In this case, as shown in FIG. 4, since the character at the fourth digit and the checksum code at the ninth digit do not match, the display alarm 14 generates an alarm indicating that the characters do not match.

Normally, the display alarm 14 displays read information and displays an alarm / error.

Incidentally, by sending the read information read by the barcode scanner 11 to the tester 18 by communication means such as GPIB, RS-232C or the like, the read information in the tester 18 can be collated with the operation program.

In this embodiment, the bar code scanner is attached to the outlet of the probe stocker, so that a mistake in removing the probe card can be prevented, so that a loss of test time can be prevented. By preventing a mistake, it is possible to prevent a device from being damaged by setting a measurement medium that is not compatible with the wafer.

In the above embodiment, the probe card is transported by a robot mechanism attached to the prober. However, in a remote place, the probe card may be transported by a self-propelled vehicle.

Further, although the form of the ID information of the probe card of the above embodiment is described taking a bar code as an example, the present invention is not limited to this.
A device using a porcelain film, characters, electromagnetic waves, or the like may be used, and any means may be used as long as it records predetermined information.

〔The invention's effect〕

In the present invention, the result output means outputs whether the input information and the read information match or does not match, and only when they match, tests the characteristics of the wafer by the measurement medium,
A measurement medium that is not compatible with the wafer is not set in the wafer test apparatus.

Therefore, it is possible to prevent the device from being damaged by setting a measurement medium that is not compatible with the wafer, and to prevent loss of test time.

In the present invention, the read probe card ID information is sent to the tester, and the characteristics of the wafer are tested based on the probe card ID information. Therefore, the read probe card ID information and the operation program (test Program), and the operation of an incompatible operation program can be prevented.

[Brief description of the drawings]

FIG. 1 is a principle view of a wafer test apparatus of the present invention, FIGS. 2 to 4 show one embodiment of a wafer test apparatus according to the present invention, FIG. 2 is a block diagram showing the overall configuration thereof, and FIG. FIG. 4 is a plan view of a label affixed to the probe card, FIG. 4 is a schematic view showing the configuration of the comparator, FIG. 5 is a side view of the wafer test apparatus, FIG. 6 is a plan view of the probe card, and FIG. Plan view of wafer, 1 ... Wafer test device, 2 ... Test circuit, 3 ... Probe card (measurement medium), 4 ... Stage, 5 ... Wafer, 6 ... Chip, 7 ... Hole, 8 ... ... probe, 9,10 ... label, 11 ... barcode scanner (reading means), 12 ... memory (holding means), 13 ... comparator (comparing means), 14 ... result output means, 15 ... Ring insert, 16… Keyboard, 17… Probe card stocker, 18… Star, 19 ...... host CPU.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/66

Claims (1)

(57) [Claims] 1. A wafer testing apparatus having a probe card for measuring a wafer according to various wafers to be tested, selectively setting the probe card, and testing characteristics of the wafer. Reading means for reading probe card ID information attached to the probe card; communication means for sending the probe card ID information read by the reading means to a tester; and input information corresponding to a wafer to be tested and input in advance. Holding means for holding; comparing means for comparing the probe card ID information read by the reading means with the input information held by the holding means; and the probe card ID information by the comparing means and the input information match. And a result output means for outputting a comparison result indicating whether the data is a match or a mismatch. The probe card ID information attached to the probe card is read out when the probe card is replaced when the probe card is attached to the outlet of the probe card stocker or during the transportation of the probe card, and the probe card ID information attached to the probe card is exchanged. A wafer test apparatus for testing the characteristics of a wafer based on the probe card ID information only when the input information corresponding to the wafer to be tested matches the input information.