JPS6387735A - Centralized marking system in wafer testing process - Google Patents

Abstract

PURPOSE:To reduce the time required for maintenance of a marking operation and utilize probers (testers) efficiently by introducing an exclusive prober for marking. CONSTITUTION:When a measurement is carried out at each wafer prober 1, lot numbers, respective category data, machine numbers and so forth are inputted to a floppy disc 3 and the measurement for every one wafer is carried out for every lot. At that time, a map which shows which chips in each wafer are acceptable and which chips in each wafer are unacceptable is memorized in the floppy disc 3. After the measurements for all wafers in one lot are completed, an operator sets both the wafers of one lot and a disc card mesmerizing the map of the lot into an exclusive prober 2 for marking as one combination. The exclusive prober 2 for marking applies markings to unacceptable chips in the wafers of the lot successively in accordance with the map memorized by the disc card. With this constitution, problems concerning operation and maintenance of the marker can be eliminated and probers themselves can be utilized efficiently.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a marking system for defective chips in a wafer test process, and particularly to a group control system for systematically controlling a large-scale wafer test process and subsequent processes. The present invention relates to a centralized marking system suitable for application to.

[Technical Background of the Invention In wafer probing, which is a co-wafer testing process, probe needles are applied to the chips on the wafer one after another, and each chip is measured by a tester connected to the probe needles. Chips that were determined to be good were marked with a marker inside the prober. In many cases, a recyclable ink method is used as the marking method. This is so that in the unlikely event that an error is made, the ink is removed and remeasured to ensure a good product.

Incidentally, with the increase in wafer production in recent years, the scale of such wafer testing processes has increased so that a plurality of probers (for example, 100 probers) are used simultaneously.

[Problems with conventional technology] However, in the conventional test process, after measuring one chip with one prober, if that chip is defective, it is immediately marked, so if there are many chips per wafer, marking is not necessary. The number of chips is also quite large, so the time spent on marking.

There was a problem that expensive testers were not operating and were not being used effectively. Furthermore, conventionally, one to four markers are set for one prober.

The setting operations for these markers are complicated, and maintenance requires a lot of effort and time. Especially in wafer test systems equipped with multiple probers.

The time required to operate and maintain the marker is enormous, and as a result, the efficiency of blobbing is reduced. or,
Since the marker is provided in the wafer prober, there is also the problem that the probe card becomes dirty due to the marker.

[Purpose of the Invention] The present invention was made to solve the various interlayer points in the conventional wafer probing system described above, and by introducing a dedicated marking prober, the time required for marking operation and maintenance can be significantly reduced. The purpose of the present invention is to provide a centralized marking system that can reduce the amount of time required and make effective use of probers (testers).

[Summary of the Invention] To achieve the above object, the centralized marking system of the present invention stores one or more wafer probers and a map representing measurement results of wafer chips by the wafer probers for each measurement unit. The present invention is characterized in that it comprises a memory means, and a dedicated marking prober that marks defective chips among the wafer chips based on the map stored in the memory means.

[Embodiments of the Invention] An embodiment of the centralized marking system of the present invention will be described below with reference to the drawings.

11th i! 1 shows a configuration diagram of a basic centralized marking system using a floppy disk, which includes 10 to 50 wafer probers 1 and one marking-only prober 2.

A floppy disk 3 is added to each of the wafer prober 1 and the marking-only prober 2 as storage means. A tester 4 is attached to each wafer prober 1. Marking-only prober 2 has 1 marker and 2 markers.
It is possible to install one or four units, and is further equipped with a CRT for displaying map data and test data or a printer (console 5) for printing. Furthermore, various data such as loft and yield for each wafer are collected by the marking-dedicated blobbing CPU.

In such a centralized marking system.

When measuring with each wafer prober, the loft No.
, product name, each category data, machine number.

Card number, test date, hour, minute, etc. on floppy disk 3
Next, measurements are made for each wafer in each loft. At this time, a map indicating which chips on each wafer are good and which are defective is stored on the floppy disk. When the measurement for 10 tons is completed, the operator places the 10 tons of wafers and the disk card that stores the map of that lot into a pair using a dedicated marking prober.
Set to . The marking-only properr 2 sequentially marks defective chips on wafers in that lot based on the map stored in the disk card.The time required for marking is much shorter than the time required for blowing, so multiple wafers can be Even if a tested wafer is sent from the prober, it can be sufficiently processed with one marking-dedicated prober.

In addition, in this system, marking is not performed during normal measurement, so even if a mistake occurs, it is possible to re-measure.The marking method is not limited to the ink method, but can also be one or more of the scratch method or laser marker method. The embodiment is an example of a basic centralized marking system in the wafer test process, but the centralized marking system of the present invention automates the wafer test process to post-processes such as baking and die bonding as shown in Figure 2. It is also suitable for use in group control systems. In this group control system, the test data and map data in the wafer test process are transferred to the GCS station 30 which has a built-in storage means 31, the wafer test is carried out by the wafer prober 1, the defective chip is marked by the marking prober 2, and the baking unit Baking according to step 6 is automatically performed. The multiplexer 7 selects signals. In this system, data and logistics are separated, so an ID is provided on the wafer side.

An automatic ID recognition device will be installed within the process. This automatic recognition device and automatic transport operate under the control of a host computer.

[Effects of the Invention] As is clear from the above explanation, in the intensive marking system of the present invention, a dedicated marking prober is provided separately from the wafer prober, and only marking can be performed intensively using a map showing the measurement results by the wafer prober. As with conventional probers, the probe card is not contaminated by the marker (in force) and the marker is not manipulated.

Problems such as maintenance are eliminated, and the prober itself can be used effectively, thereby realizing speeding up and automation of the wafer testing process. Furthermore, since marking is not performed during measurement, there is an advantage that any marking method can be selected.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a centralized marking system of the present invention, and FIG. 2 is a block diagram of a group control system using the present invention. 1...Wafer Proper 2...Marking Prober 3...
・・Floppy disk (storage means)'4・・・・・・・
tester

Claims (1)

[Claims] one or more wafer probers; a storage means for storing a map representing the measurement results of the wafer chips by the wafer prober for each measurement unit; A centralized marking system characterized by comprising a dedicated marking prober that marks chips.