JPH034544A - Position recognition pattern - Google Patents

Abstract

PURPOSE:To judge the positional relation between semiconductor chips by a position recognition pattern and to enhance a recognition accuracy by a method wherein recognition marks are respectively arranged at the corner parts of the chip by which the opposite angles of a quadrangular semiconductor chip are formed. CONSTITUTION:Recognition marks 12a and 12b are respectively arranged at the corner parts, by which the opposite angles of a quadrangular semiconductor chip 11 are made, of the chip 11 and the marks 12a and 12b are formed into a quadrangular form and are arranged on the sides inner slightly from the outer peripheries L of the chip. An area with a feature is previously ready-stored in a memory as a reference pattern in a processing system 8, a position recognition pattern which is formed by the marks 12a and 12b of the chip 11 is read out by a camera 7 and the position recognition pattern detected by the processing system 8 is compared with the previously stored reference pattern. An area having most meeting points is recognized as a target pattern, the amount of the positional deviation of the center of the reference pattern from the center of the recognized pattern is read and the final wire bonding position is decided.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a chip position recognition device installed in an automobile, etc., and more specifically, to a device for determining the positional relationship of semiconductor chips by automatic pattern recognition. It concerns location recognition patterns.

[Prior Art] Conventionally, for example, an aluminum wire bonding apparatus for a power transistor is equipped with a device for recognizing a chip position. That is, by reading a position recognition pattern based on marks formed on a semiconductor chip and knowing the positional relationship of the chips, the position of a wire bonding pad formed on the chip is identified. 2 to 4 show examples of position recognition patterns formed on this chip, with marks 2, 3.4a, 4. b is placed. FIG. 5 shows an example of the chip position recognition device 5, in which a light 6 illuminates the chip 1, a camera (@image device) 7 reads out the pattern formed by the mark, and a processing system 8 reads out the pattern formed by the mark. The positional relationship of the chip 1 is determined by comparing the pattern with a pre-stored pattern. In addition, in FIGS. 2 to 4, 9 indicates a bonding pad.

[Problems to be Solved by the Invention] However, since the position recognition patterns shown in FIGS. 2 and 3 have only one mark, and the position recognition pattern shown in FIG. Because of the location, location recognition accuracy was poor.

An object of the present invention is to provide a position recognition pattern that can improve recognition accuracy.

[Means for Solving the Problems] The present invention provides a chip positioning system in which a recognition mark is formed on a rectangular semiconductor chip, and a position recognition pattern based on the recognition mark is read by an optical system to determine the positional relationship of the semiconductor chips. In terms of recognition accuracy, a position recognition pattern is used in which recognition marks are placed at each diagonal corner of a rectangular semiconductor chip, and at least one of the recognition marks is square shaped and placed inward from the outside periphery of the chip. This is the summary.

[Operation] Recognition marks are arranged at each diagonal corner of a rectangular semiconductor chip, and at least one of the recognition marks has a rectangular shape and is arranged inward from the outer periphery of the chip. Then, the position recognition pattern based on this recognition mark is read by an optical system, and the positional relationship of the semiconductor chips is determined.

[Embodiment] Hereinafter, an embodiment in which the present invention is embodied in a chip position recognition device that can be used in an automatic bonder will be described with reference to the drawings.

FIG. 1 shows a plan view of the semiconductor chip 11 of this embodiment, and the semiconductor chip 11 on which power transistors etc. are formed is shown.
is formed into a square shape. An aluminum electrode is disposed on most of the surface of the semiconductor chip 11, and an oxide film, a nitride film, or a resin film such as polyimide is disposed on the circled portion. The two recognition marks 12a and 12b each have a rectangular shape, and are arranged at each diagonal corner (corner) of the semiconductor chip 11. This recognition mark 12a.

The arrangement position of the recognition marks 12b is slightly (distance 2j) inward from the outer periphery of the semiconductor chip 11, and is arranged so that the longitudinal direction of the recognition marks 12a and 12b is directed toward the center of the semiconductor chip 11. has been done.

There is no aluminum in this mark area, and the surface is covered with an oxide film (or
(nitride film or resin film), and the semiconductor chip 1
1 Most of the surface is white because it is made of aluminum electrodes,
The position recognition pattern made up of the recognition marks 12a and 12b appears blackish. In this way, a black and white controller 1 is placed on the chip surface.
~I can do the last one.

The marks 12a and 12b are formed during the assembly process (
This is done in the wafer process (pre-process) where chips are made on the wafer before entering the post-process.

Then, the position of the semiconductor chip 11 is recognized by the chip position recognition device 5 shown in FIG. That is, in the processing system 8 including the computer, a characteristic area is made into a standard pattern and stored in memory in advance, and the recognition marks 12a, 12 of the semiconductor chip 11 are used with the camera (imaging device) 7.
The position recognition pattern formed by b is read out, and the processing system 8 compares the detected position recognition pattern with a standard pattern previously stored in the memory. Then, the area with the most matching points is recognized as the target pattern, and
The amount of positional deviation between the center of the standard pattern and the center of the recognized (detected) pattern is read to determine the final wire bonding position.

Thereafter, wire bonding to a predetermined position is performed.

As described above, in this embodiment, recognition marks 12a are provided at each diagonal corner of the rectangular semiconductor chip 11.

12b, and their recognition marks 12a.
, 12b had a square shape (rectangle) and were arranged slightly inside from the outer periphery of the chip. As a result, since there are two recognition marks and the recognition marks are placed at the farthest diagonal positions on the depth 11, recognition accuracy can be improved.

Also, during pattern recognition, as shown in Figure 6, mark 1
3a and 13b are fLJ-shaped, the scribe line (scribe pattern) 14 around the chip 1 as shown in FIG. 7 and the protruding portion 15 of the chip mount 1 to the material as shown in FIG. There is a risk of misunderstanding.

However, as in this embodiment, by making the marks square and arranging them as shown in 12a and 12b in FIG. This prevents erroneous recognition of the protruding portion 15), the shadow of the chip, etc. as a position recognition pattern.

Note that this invention is not limited to the above embodiments,
For example, the recognition mark may be a square instead of a rectangle, roughly the recognition mark 12a.

The corners of 12b may be formed into an arc shape or may be cut out at a predetermined angle.

Furthermore, the marks placed diagonally on the semiconductor chip 11 are
Either one of the recognition marks may have a rectangular shape and be placed inward from the outer periphery of the chip, or one of the marks may have a shape other than the rectangular shape.

That is, for example, as one of the marks, a black and white contrast portion provided at a corner of the semiconductor chip and depending on the presence or absence of an aluminum electrode on the semiconductor chip in layout design may be used.

[Effects of the Invention] As described in detail above, the present invention exhibits an excellent effect of improving recognition accuracy.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a semiconductor chip according to an embodiment, FIG. 2 is a plan view of a semiconductor chip for explaining a conventional technique, FIG. 3 is a plan view of a semiconductor chip for explaining a conventional technique, and FIG.
The figure is a plan view of a semiconductor chip to explain the conventional technology.
FIG. 5 is a schematic diagram showing a recognition device, FIG. 6 is a plan view of a semiconductor chip for comparison, FIG. 7 is a plan view of a semiconductor chip for comparison, and FIG. 8 is a plan view of a semiconductor chip for comparison. FIG. 5 is a chip level recognition device, 6 is a light, 7 is a camera, 8
is a processing system, 11 is a semiconductor chip, 12a is a recognition mark,
12b is the recognition mark, and shi is the outer periphery.

Claims (1)

[Claims] 1. In a chip position recognition device in which a recognition mark is formed on a rectangular semiconductor chip, and an optical system reads the position recognition pattern formed by the recognition mark to determine the positional relationship of the semiconductor chips, the diagonal of the rectangular semiconductor chip is used. A recognition mark is placed at each corner of the
A position recognition pattern characterized in that at least one of the recognition marks has a rectangular shape and is arranged inward from the outer periphery of the chip.