JPS58158936A - External lead detector of semiconductor device - Google Patents

Abstract

PURPOSE:To perform automatic wire connection of multiple external lead terminals by a method wherein the position of individual external lead patterns is detected as a relative position to a reference mark. CONSTITUTION:A device 5 is scanned by a TV camera 8 on table 6 for making into specimens the image elements of N-N and converting them into binary values 9 for memory 10. Firstly, the regions 160, 161 are scanned to detect 12 the central position of the reference marks 150, 151, further scanning the lead position based upon the coordinates system in the order of the sections 162, 163... slightly overlapped one upon another. When the memory 10 is read out by the address control unit 11, the read out direction is selected in accordance with the array of leads to detect 13 all leads by means of repeating the same process. That is, the data in the image memory 10 are read out by raster scanning process determining the center coordinates of the leads from the center of transient position to decide the firstly vanishing position as the lead terminal. Then the detected position is memorized 14. Through this constitution, the automatic wire connection may be performed very accurately by means of adding lead terminals to a wire connecting device with multiple pins.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the assembly of semiconductor devices, such as ultra-high integrated circuits (hereinafter referred to as VL8 I) mounted in a ceramic case, and includes VLSI wires equipped with a large number of 4IK external lead terminals. This is a device that automates bonding.

Among semiconductor devices, integrated circuits called 4hVL8I (hereinafter referred to as KIC) have a tendency to increase the number of external lead terminals to 4I, that is, to increase the number of bins, except for some devices such as memory. .

This is inevitably derived from the increase in the number of gates integrated into one IC, and P m 3.5
X G"' Here, P represents the number of pins, that is, the number of external lead terminals, and G represents the number of darts.As the 51CVL81 becomes more highly integrated, the number of leads that serve as external terminals also increases exponentially. .

However, simply increasing the size of the case is not desirable because it increases the delay time of the electronic circuit, and the width of the leads for wire bonding formed in the case of the semiconductor device and the arrangement interval thereof have to be reduced.

In cases used for semiconductor devices, such as ceramic cases, the position of each external lead pattern ultimately formed differs from the designed position due to subtle differences in shrinkage rate during firing. .

In addition, the lead width has become smaller, and the typical point on the pellet and external lead can be reduced to 1 or 2 liters, respectively.
The bonding method detects the location and automatically corrects the positional deviation while bonding.

In this case, it is sufficiently practical to have an electrode array pattern formed on an IC that has accurate mutual relationships during the wire bonding process and has a sufficient external lead width.

However, as mentioned above, in such a multi-bin semiconductor device, the positions of external lead patterns vary and the lead width is small, so it is extremely difficult to perform automatic bonding using the above-mentioned apparatus and method. This results in a significant decrease in yield.

The external lead detection device for a semiconductor device according to the present invention compensates for such drawbacks by rounding and detects the position of each external lead pattern as a relative position with respect to a reference mark. By using K, it is possible to perform bonding work with sufficient kIII+ precision even in a conventional automatic wire bonding apparatus. Here, the external lead detection device for a semiconductor device according to the present invention can be added to the front stage of the bonding stage in a conventional wire bonding device, or can be configured as an independent device separate from the wire bonding device to detect the lead position. It is also possible to supply only the information using a storage medium.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an external lead inspector for a semiconductor device according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an example of an external view of a ceramic case of a semiconductor device to which the present invention is applied, and a semiconductor element 4IkVLS I 2 is fixed to the semiconductor device case 1. The case IK of the semiconductor device has external leads 3 and reference marks 4.
is formed. In general, when VLSIj has multiple bins on the back, the case size also becomes thicker! The size of the portion designated as P-san is approximately 10 meters square. For this reason, in order to input images of all leads at once and ensure the necessary accuracy, k is 1.
It is necessary to input the image as an image having a 0,000 x 10,000 or more Emoto conversion point, which is quite difficult in practice.

Therefore, a practically effective method is to install the TV camera #txy table for charging conversion, divide it into small areas, sequentially scan them, and detect the leads included in each small area, that is, one screen. .

The second WJ is a diagram showing a configuration example of an external lead detection device for a semiconductor device according to the present invention.
The images are sequentially scanned using a TV camera 8 mounted on the camera.

TV camera? 8 is sampled into NXN10 pixels and converted into black and white, that is, "1" using the binarization circuit 9.
It is converted into a binary image of ' and 0''. This binary scratch image is
It is stored in a one-time memory 10' having a size of NXN.

When one screen worth of data is stored in the ij image memo 910,
The next scanning position is commanded by the XY table control unit 7 and
The Y table 6, that is, the TV camera 8 starts moving.

ml image memo
2, and the center position of the reference mark is removed. At the time of lead detection, the reading direction of the lli image data is controlled by the address control mttK, and the lead detection section 13 can detect all the leads in a single geographical area. The detected lead position is converted into a relative position IIK with respect to the reference mark, and is stored in a storage medium 14 such as a memory or a cassette tape.

ji3#A shows an example of a scanning procedure when detecting a reference mark and a lead. First, the reference mark 150.
Two areas 160 and 161 of reference mark 151 are scanned to detect the center position Mk of reference mark 150 and 151 by reference mark detection unit 12 shown in FIG. After that, based on the coordinate system of the reference mark, change the read position in the counterclockwise direction k162.
As shown in 16B, the entire lead existing area is sequentially scanned with some overlap. This overlap is for determining a lead that spans one edge without error.

The reference marks 150 and 151 shown in FIG. 3 serve as references on the lead side in the wire bonding process, and may have any shape as long as they are characteristic.

FIG. 4 shows an example of a method for detecting a reference mark, taking a ten-shape as an example. In other words, for the ten-shaped reference mark 15 [,
This generates 19 small reticle 11, reticle 1
7 is the center position of the reference mark, which is the center position of the reticle where a pattern of a constant width crosses all four directions, and where the four quantities indicated by Hōnaka-machi and Machi s”ap-machi are the same,
The circuit for realizing this tin layer can be easily achieved using the current technology, so it will not be described in detail here.

Figure 5 shows the address system n that becomes [111' when a read is detected.
2 is a diagram showing the functions of the il m 11, which realizes four modes for transferring binary #rut data to the detection unit 1341C shown in FIG. 2. That is, the 21st dK with NXN pixels
When reading the data of the image memory IO shown in FIG.
2. It is transferred to the lead detection unit 13 shown in FIG. 2 in the order of 183. flil, Fig. 5 (bl is used in the case of the left lead dome and indicates that it is transferred in the order of 184.185.186, and Fig. 5 101 is used in the case of the lower lead 4 and indicates the order of 187.188.189. Order, FIG. 5 shows that in the case of right lead n, the order is transferred to the lead detection unit 13 with the order of 190.191.192.

Lead detection 11113 is performed by the above r address control 811.
In this case, it is possible to detect leads in all directions of the semiconductor device case using exactly the same process as in the case of FIG. Further, in this case, unlike rotating the mechanical KTV camera 2, no deterioration of 5M degrees is observed.

FIG. 6 is a diagram showing a method of detecting the read f in the read detecting section 13. When data in the image memory IO is read out using the two-star scan method, 241, 24 as shown in FIG.
2.24:l) The order teno signal is each 'l 1161Etb
lK shows 251.252.253 K appears as shown. In lead position detection, the point where vl changes to, the sequence K
By finding the point where VM changes to ■, that is, the center of the transient position, find the center coordinates of the lead,
The end point can be determined by finding the position where the above-mentioned transient disappears first among consecutive sisters.

By doing the above, the center position of the lead at a certain distance from the end point, that is, the bonding position, can be adjusted to Jl! can be detected.

As mentioned above, 5IIc1 outside f of the semiconductor device according to the present invention
If you use the li9-code detection class, you can create multi-bin LSI
In assembly work JIC wire bonding work, simply connecting the conventional bonding equipment WLK additionally is sufficient! A highly satisfactory automation device can be easily realized.

[Brief explanation of drawings]

FIG. 1 is an external view of a semiconductor device to which the present invention is applied, and FIG.
1 is a diagram showing an embodiment of the external lead detection device for a semiconductor device according to the present invention, FIG. 1iia is a diagram showing an example of a scanning procedure,
Figure 94 is a diagram for explaining the method of detecting the reference voltage, #
FIG. 15 is a diagram for explaining the expansion of the address control section, and FIG. 6 is a diagram for explaining the lead detection method. In the figure, 1 is a ceramic case of a semiconductor device, 2 is a semiconductor element,
3゜20, 21, 22, 23 are external leads, 4
, 15, 150.151 are reference marks, 5 is a semiconductor device roughly positioned, 6 is an XY table, 7 is an XY table control unit, 8 is a TV right camera 9 is a binarization circuit, l (J is lii image memory, 11 is address system # section,
13 is a reference mark detection section, 13 is a lead detection section, 14 is a storage medium, 160° 161, 162.163 are scanning positions, and 17 is a gang mark detection L/? ri4.181.182
．． 183.184.185.186.187. IW. 189, 190.191.192 are the image data pa extraction order, 241°242, 243 are the read raster, and 251.252.253 are each 241.242.24
3 shows a gun ejection signal corresponding to No. 3. t 1 Figure 3 Figure 3 Figure L-Normative Figure 5) 9I

Claims (1)

[Claims] TV for charging and converting external lead images of semiconductor devices
an XY table and an XY table control unit for moving the TV right camera on the XY plane; a binarization circuit for converting an external lead l1iii image into black and white binary;
An lIjgII memory for storing the above-mentioned binary ij key, an address control unit for sequentially reading out two pieces of image data from the direction corresponding to the scanning position, and a reference mark detection unit for reading the reference mark formed on the case of the semiconductor device. A photoelectric conversion camera fixed to the XY table detects the external leads formed on the case of the semiconductor device, which is roughly positioned in advance. Divide the entire area in which there exists [sequentially scan, and send each ij image data to address control MIK corresponding to the read arrangement, that is, TV
By selecting the lead-out direction corresponding to the right camera scanning position, each lead position existing in each area by repeating the same tin layer is individually detected and stored as a relative position with respect to the reference mark. Vertical detection of external leads of semiconductor devices.