JPH0142499B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a pattern recognition method and apparatus capable of detecting the position of a pattern to be recognized obtained as a bright spot image.

(2) Background of the technology In automatic assembly of integrated circuits (ICs), when performing wire bonding between the IC pad and the wiring leads formed on the package, it is necessary to recognize the pads and wiring leads and detect their positions. must be done. Among these two types of recognition and position detection, wiring leads have unique problems, and conventional techniques have not been able to recognize them with a high recognition rate and detect their positions. Development is eagerly awaited.

(3) Conventional technology and problems The problem is that the surface of the leads (thick film screen printing pattern) formed on ordinary IC packages has minute irregularities, so it is difficult to view such surfaces with a TV camera, etc. When an image is captured, the image becomes a bright spot image. If the bright spot image is not subjected to any processing, the outer shape of the wiring lead cannot be detected from the bright spot image.

(4) Purpose of the Invention The present invention was devised in view of the drawbacks of the conventional techniques as described above, and its purpose is to provide pattern recognition that can detect the position of a pattern to be recognized even when the pattern is obtained as a bright spot image. An object of the present invention is to provide a method and a device thereof.

(5) Structure of the Invention These objects are to divide the pattern data area to be recognized into small areas, and when the number of pattern data bits in the small area is larger than a predetermined value, This is achieved by forming a new recognized pattern data area as 1-bit pattern data and detecting its position.

(6) Embodiments of the invention Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the invention. Reference numeral 1 denotes an IC package, which, as shown in FIG. 2, has an IC chip 3 mounted inside the IC package body 2, and a pad of the IC chip 3 (not shown) and wire bonding around it. Leads 4 are formed.

In FIG. 1, 5 is an imaging system and 6 is a TV camera. 7 is a TV camera driver connected to the TV camera. This driver is the binarization circuit 8
It is connected to the first image memory 9 via. The memory 9 is configured to store the recognized pattern data from the binarization circuit 8 in synchronization with the TV camera 6. 10 is a small area dividing circuit that divides the recognized pattern data area stored in the memory 9 into small areas. 11 counts the number of pattern data bits in the small area divided by the circuit 10, and in response to the value being greater than a predetermined value, sets the small area as one pattern picture element (bit) to the second
This is a small area bit counting circuit which is stored in the memory 12 of . 13 is a pattern position detection circuit connected to the second memory 12;

14 is a first image memory 9 and a small area dividing circuit 1
0, a control system that is connected to a small area bit counting circuit 11, a second image memory 12, and a pattern position detection circuit 13 to control these.This control system is also connected to an XY stage controller 15. There is. The controller 15 is the IC package 1
Controls the XY stage 16 that controls the position of the TV camera 6.

Next, the operation of the apparatus of the present invention having the above configuration will be explained.

The XY stage 16 is moved by the XY stage controller 15 under the control of the control system 14 so that the area including the leads 4 of the IC package 1 as shown in FIG. 2 is within the field of view of the TV camera 6. Ru.

The TV camera 6 detects the pattern signal within the above field of view.
2 from TV camera 6 via TV camera driver 7
It is supplied to the digitization circuit 8, where it is binarized and the first
The image is taken into the image memory 9 of. An example of the visual field pattern area (a×b) (hereinafter referred to as a pattern data area) captured in the memory 9 is shown in the third example.
It is shown in Figure 3-1.

This pattern data area is the small area dividing circuit 10.
The image is divided into small areas (a/n×b/n) (each small frame) as shown in 3-2 in FIG. 3 and read out. The number of pattern bits in each small area is counted by the small area bit counting circuit 11, and when the counted value is greater than or equal to a predetermined value, that small area is regarded as one pattern picture element (bit) and the second pattern bit is counted. is stored in the image memory 12 of. If the above count value does not reach the predetermined value, the small area is
It is stored in the second image memory 12 as a non-pattern picture element (bit). In this way, memory 12
The new pattern data area stored in is shown at 3-3 in FIG.

Corner points A and B (2-4 in FIG. 2) of the pattern data area of the memory 12 are detected by a pattern position detection circuit 13 using a known pattern position detection method, and its output is detected by a wire bonder using an automatic wire bonder, for example. is used for control.

As described above, according to the present invention, the pattern data area taken into the memory 9 is divided into small areas, and it is determined whether or not the small areas should be used as pattern data bits. Since the pattern data area after processing is used as a new pattern data area, even if the pattern to be recognized is a pattern such as the above-mentioned lead, there will be no problem in detecting the position of the pattern, for example, a corner.

In the above embodiment, an example was explained in which the first image memory and the second image memory are separate, but they may be a single memory.

(7) Effects of the Invention As described above, according to the present invention, even a pattern obtained as a bright spot image from an object to be recognized can accurately detect its position.

Effects such as being able to configure a device that achieves this effect relatively easily can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing an embodiment of the present invention.
FIG. 3, a perspective view of the IC package, is a diagram schematically showing a memory storage mode for explaining the operation of the device of the present invention. In the figure, 1 is the IC package, 6 is the TV camera, and 7
is a TV camera driver, 8 is a binarization circuit, 9 is a first image memory, 10 is a small area dividing circuit, 11 is a small area bit counting circuit, 12 is a second image memory, and 13 is a pattern position detection circuit. It is.

Claims (1)

[Claims] 1. The pattern data area to be recognized is divided into small areas, and either the number of pattern data bits or the number of non-pattern data bits in the small area is counted, and the value is determined in advance. A pattern recognition method characterized in that when a predetermined relationship exists with respect to a value, a new pattern data area to be recognized is formed using the small area as a unit bit to detect a pattern shape. 2. A first image memory that stores recognition pattern data, a small area dividing circuit that divides the recognition pattern data area in the image memory into small areas and reads them out, a second image memory, and the small area a small area bit counting circuit that counts the number of pattern data bits within the image and, when the value is larger than a predetermined value, stores the small area as 1-bit pattern data in the second image memory; A pattern recognition device comprising: a pattern position detection circuit that detects the shape of a new pattern data area to be recognized stored in a second image memory.