JPS63208238A - Pellet selecting apparatus - Google Patents

Abstract

PURPOSE:To provide a pellet selecting apparatus, which automatically classifies each pellet, by a constitution wherein a mark reading means is provided, and a pellet moving means, which classifies the pellet into any of a plurality of predetermined places based on selecting information and relative position information that are outputted from the reading means, is provided. CONSTITUTION:A reading circuit 11 recognizes an input electric signal and converts the signal into a binary-coded signal. The circuit 11 reads a mark and detects the relative position of the mark based on the changing timing of the binary-coded signal and scanning timing. Then a signal including selecting information and relative position information is outputted. A selection control circuit 12 controls the position of a supporting table 14 of a manipulator 13 based on the relative position information in the input signal, moves a head 16 on a pellet 2 corresponding to the relative position of the mark and controls a driving circuit 15 based on the selecting information in the input signal. The driving circuit 15 drives the head 16 based on this control. For example, when the mark is a defective mark 4, the head 16 attracks the pellet 2, which is located at the position where the head is moved, and carries the pellet to a defective pellet receiving pan. The pellet is accommodated in the receiving pan. Thus the pellets are automatically classified.

Description

[Detailed Description of the Invention] [Industrial Application Field] ' The present invention relates to a pellet sorting device, and in particular, in the process of manufacturing semiconductor devices, it automatically sorts each pellet based on the results of an electrical property test performed on a wafer. This invention relates to a pellet sorting device that separates pellets into different types.

[Conventional technology]

Electrical property tests are performed on each pellet, each with a semiconductor device formed thereon, to determine whether each pellet is good or bad. Ink markings or scratch markings are applied to defective pellets, and the pellets are judged good or bad based on these markings. Traditionally, it was divided into sections.

However, with the above marking method, if a defective part of the test equipment accidentally marks a good pellet as defective, the pellet becomes unusable and the marking cannot be repaired. Marks on pellets can easily be confused with circuit patterns, leading to misreading, and sometimes the classification cannot be seen unless all pellets are marked one by one. There is.

In order to solve these drawbacks, a marking method different from the above (hereinafter referred to as the batch marking method) was developed.
was proposed.

FIGS. 2 and 3rA are explanatory diagrams for explaining an example of the batch marking method.

As shown in FIG. 2, in a part of the periphery of the wafer 1, there is a space other than the pellet 2 on which semiconductor devices are normally formed. One or more (four in FIG. 2) marking areas 3 are set in these nine spaces, and a defective mark 4 is marked in one of them at once, as shown in FIG. 3, for example. The defect mark 4 is a dot mark made by a laser beam or the like, and these defect marks 4
The relative position of corresponds to the relative position of a defective pellet among the pellets 2 within the wafer 1. It's defective mark 4
The quality of each of the pellets 2 can be determined by knowing their relative positions.

This type of batch marking method prevents markings from being confused with circuit patterns and misreading them by setting multiple marking areas so that even if you make a mistake, you can redo the marking and make a good pellet unusable. There is less risk of this occurring, and there is no need to check whether each pellet is marked one by one. Furthermore, since the pellets are not directly marked, it is also possible to classify each pellet into performance stages through an electrical property test on the wafer, and then apply marks representing this classification all at once in the marking area.

As explained above, the batch marking method has various advantages, but no pellet sorting device has been proposed so far that automatically sorts each pellet from a wafer that has been batch marked in this way.

[Problem that the invention seeks to solve]

The purpose of the present invention is to automatically mark each pellet by reading the marks that are applied to the marking area of the υ wafer by the above-mentioned batch marking method and which represent sorting information such as quality of each pellet and classification by performance stage. An object of the present invention is to provide a pellet sorting device for sorting pellets.

[Means for solving problems]

The pellet sorting device of the present invention displays sorting information for each of a plurality of pellets on a wafer, each of which includes a semiconductor device, together with relative position information for each of the pellets, and displays the sorting information for each of the plurality of pellets on the wafer, together with the relative position information for each of the pellets. marking reading means for optically reading marks applied all at once and outputting the sorting information and the relative position information; and a pellet moving means for sorting the pellets into one of a plurality of predetermined locations.

〔Example〕

The present invention will be described in detail below with reference to drawings showing embodiments.

FIG. 1 is a block diagram showing an embodiment of the pellet sorting device of the present invention.

The embodiment shown in FIG. 1 includes a wafer support stage control circuit 7,
A wafer support stand 8 that is movable in two orthogonal axes under the control of a wafer support control circuit 7, a laser scanner 9, and a photoelectric converter 1 that receives (scattered light of) the output light of the laser scanner 9.
0, a reading circuit 11 that controls the scanning of the laser scanner 9 and inputs the electrical signal output from the photoelectric converter 10, a sorting control circuit 12 that inputs the signal output from the reading circuit 11, and a manipulator 13. It is composed of The manipulator 13 includes a support base 14 that is movable in two orthogonal axes directions under the control of the sorting control circuit 12, a drive circuit 15 that is supported by the support base 14 and controlled by the sorting control circuit 12, and a drive circuit 1.
5 and a head 16 driven by a motor.

FIG. 4 is an explanatory diagram showing the wafer setting method in the embodiment shown in FIG.
) is a sectional view taken along line A-A in (a).

The electronic sheet 5 is a stretchable adhesive sheet. A wafer as illustrated in FIG. 2 is pasted on an electronic sheet 5, cut into pellets 2 and marking areas 3 each, and then the electronic sheet 5 is stretched in two orthogonal axes directions, as shown in FIGS. It is fixed to the fixing ring 6 as shown in b). The fixing ring 6 is fixed on the wafer support 8.

The wafer support table control circuit 7 adjusts the position of the wafer support table 8 so that the marking area 3 to be read on the wafer set on the wafer support table 8 as described above is within the scanning area of the laser scanner 9. Automatically adjust. Since this adjustment may be performed several times at most for one wafer, manual adjustment may be used instead of automatic adjustment by the wafer support control circuit 7.

The laser scanner 9 is controlled by the reading circuit 11 to scan the marking area 3 with a laser beam, and the laser beam scattered in the marking area 3 is photoelectrically converted by the photoelectric converter 10 to become an electric signal. The magnitude of this electrical signal is determined by the marking area 3.
This changes depending on whether or not there is a laser beam on the mark (representing sorting information) applied to the image. The reading circuit 11 identifies the input electrical signal, converts it into a binary signal, reads the mark, detects the relative position of the read mark based on the timing at which the binary signal changes and the scanning timing, and compares the relative position with the sorting information. Outputs a signal including position information.

The sorting control circuit 12 controls the position of the support base 14 of the manipulator 13 based on the relative position information in the input signal, moves the head 16 onto the pellet 2 corresponding to the relative position of the mark, and moves the head 16 onto the pellet 2 corresponding to the relative position of the mark. The drive circuit 15 is controlled based on the selection information. Through this control, the drive circuit 15 drives the head 16. For example, if the mark is a defective mark 4, the head 16 drives the pellet 2 at the moved position.
It is moved by a defective product receiving tray (not shown) t and stored in this receiving tray. Similarly, the pellet 2 corresponding to the relative position where the defective mark 4 in the marking area 3 is not applied.
can also be stored in a non-defective tray (not shown).

The embodiment shown in FIG. 1 includes a laser scanning device 9 and a photoelectric converter 10.
・? A signal including sorting information and relative position information is obtained by the marking reading means consisting of the &-reading circuit 11.
The Mar-Young reading means can also be constituted by a video camera whose field of view is the marking area, and a circuit that outputs a signal containing sorting information and relative position information from the video output of the video camera and the scanning signal.

In the embodiment shown in FIG. 4, the time it takes for the reading circuit 11 to output all the information in the marking area 3 is usually much shorter than the time it takes for the manipulator 13 to move one pellet 2. If a plurality of manipulators 13 are operated in parallel by using several manipulators 13, it is possible to shorten the time required for the Kyoshi division.

〔Effect of the invention〕

As explained in detail above, the present invention has the effect of providing a pellet sorting device that automatically sorts each pellet on a wafer after it has been marked by the batch marking method. Since the operator can read the marks on each pellet one by one and automatically classify them in a short time without spending a lot of man-hours in case of misreading, the cost of pellet sorting in the semiconductor device manufacturing process can be reduced. It has the effect of reducing the

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the pellet sorting device of the present invention, FIGS. 2 and 3 are explanatory diagrams for explaining an example of the batch marking method, and FIG. FIG. 3 is an explanatory diagram showing a wafer setting method in the embodiment shown in FIG. D, (a) is a plan view,
(b) is a sectional view taken along line A-A in (a). 1...Wafer, 2...Pellet, 3
...Mah? hmm! Area, 4-...Failure mark, 5...Electronic sheet, 6-...
...Fixing ring, 7...Wafer support stand control circuit, 8...Wafer support stand, 9...
...Laser scanner, 10...Photoelectric converter, 11
...Reading circuit, 12...Selection control circuit, 13.Old manipulator, 14..Support stand, 15..Drive circuit, 16.. ····head. Bamboo 1st ye'i 2 Figure Shoulder 4 Seki City

Claims (1)

[Claims] Sorting information for each of a plurality of pellets on a wafer, each having a semiconductor device formed thereon, is expressed together with relative position information for each of the pellets, and marks made all at once within a marking area set in an empty space on the wafer are optically scanned. marking reading means for reading the marking information and outputting the sorting information and the relative position information; and one of a plurality of predetermined locations for each of the pellets based on the sorting information and the relative position information output by the reading means. A pellet sorting device comprising a pellet moving means for sorting pellets into crabs.