JPS5867033A - Wire bonding method - Google Patents

Abstract

PURPOSE:To provide full automatic wire bonder independently of the number of lead pins, by a method wherein all the lead position is recognized by using a line sensor, and wire bonding is performed at the center of the recognized leads. CONSTITUTION:An image of lead 19 on a substrate mounted on a semicondutor device 8 is formed by an image-forming lens 7 on a line sensor of a line camera 1 in proper magnification through a mirror 4. The line sensor, when it detects the image, is positioned almost at a right angle to the lead. At this time, if optical scanning is performed by a line sensor, the output becomes amplitude information corresponding to its intensity of illumination. Binary coded signal wave form is transmitted to a calculator 17 through an interface 16 to detect the center position of the lead 19. The calculator 17 controls a motor driving circuits 11, 12 and 13, as well as motors 3, 6 and 9 through an interface 15. At the same time, the calculator 17 controls a motor driving circuit 14 and a motor 2, a performing wire bonding between the center position recognized by the lead 19 on the substrate through a bonding tool 5 and a electrode on the semiconductor element 18 detected by the line camera 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire bonding method for wire bonding electrodes on a semiconductor element and lead portions on a mounting board.

To detect the position of the lead part on the mounting board, conventional two-dimensional cameras are used to detect the position of two typical lead parts with characteristics, and other lead parts are detected by the above-mentioned detection method that has been learned or memorized in advance. The bonding position is calculated based on the relative positional information of the two lead parts, and wire bonding is performed. However, the number of leads on a semiconductor device is large, and as miniaturization accelerates, high precision is required for wire bonding positioning. Furthermore, the spacing accuracy between each lead is poor, and the leads themselves have many variations in size and shape. ing.

Therefore, the conventional recognition method, which recognizes representative positions and calculates the bonding positions of all the leads, cannot satisfy the bonding position accuracy. Therefore, wire bonding is impossible. Furthermore, even if the wire bonding position is determined by recognizing each characteristic position of the lead 19 or a position unrelated to the bonding position and calculating the wire bonding position from that position, the wire bonding is It is difficult to do so. Therefore, if a different position pressure is applied to the 1 illumination position and the wire bonding position, the accuracy of wire bonding cannot be satisfied. Therefore, the position is detected by visual observation or by using a two-dimensional camera with one lead. However, this method has problems in terms of reliability and productivity.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wire bonding method that eliminates the above-mentioned drawbacks of the prior art and enables highly accurate wire bonding between electrodes on a miniaturized semiconductor element and lead portions on a mounting board. .

Specifically, the present invention uses a licensor (self-scanning solid-state image pickup device) for the purpose of high-accuracy and high-speed recognition, and detects the position of a lead part with high precision of several tens of pixels in 1-picture width, thereby improving the mounting of semiconductor devices. Perform the position g* of each and every lead part on the board,
This l! This wire bonding method is characterized in that the center position of the identified lead portion is set as a wire bonding position, and wire bonding is performed to that position. For this purpose, wire bonding is performed regardless of the accuracy of the lead width and lead spacing of the lead portion on the mounting board.

The present invention will be specifically described below based on embodiments shown in the drawings.

FIG. 1 shows one embodiment of the present invention, in which a semiconductor device 8 is placed on a bonding table 10 that is movable in the θ direction. The line camera 1 is located on the same XY table 24 as the bonding tool 5, and the line sensors C, C0D1, etc.
The wire bonding position of the lead 19 on the semiconductor device substrate is detected in the field of view 20 of the line sensor of the self-scanning dust sensor. That is, the leads 19 on the mounting board of the semiconductor device 8 are connected to the imaging lens 7 through the mirror 4.
An image is formed on the line sensor of the line camera 1 at an appropriate magnification. Figure 2 (α
), the positions K are approximately perpendicular to each other. An enlarged view of a portion thereof is shown in FIG. 2(A). At this time, when the line sensor of the line camera 1 performs optical scanning, the output is as shown in FIG.
d.

The amplitude information corresponds to an illuminance of 19 g, and is binarized in the signal processing circuit 15 using a threshold value Vrx. The binarized signal waveform shown in FIG.
It is sent to the computer 17 via. The computer 17 calculates the center position t, ~tl of the binarized signal from the reference position P (scanning period signal), and calculates the center position t, ~tl of the binary signal, and calculates the center position of the lead 19 (see FIG.
Points 24eL, 24h on the field of view 20 of the line camera
, 24c, 24dN24g) are detected and this position is determined as the wire bonding position. Next, the computer 17 connects the motor drive circuit 13 via the interface 16 to the motor drive circuit 13. The motor 9 is controlled to rotate the bonding table 10, and the Kx-y table 24 is then connected to the line camera 1 by the motor 3.6.
along with the pointing tool 5 in the X-Y direction, and the optical imaging position of the line senna is moved to 20, 21, 22, 25 as shown in FIG. Detect with. In order to perform wire bonding to the wtIIIt position, the computer 17 connects the motor drive circuits 11, 12, and L via the interface 15.
5, controls the motor 5.6.9 and simultaneously controls the motor drive circuit 14. The motor 2 is controlled, and the bonding tool 5 performs wire bonding between the U-identified center position of the lead 19 on the mounting board and the electrode on the semiconductor element 18 detected by the line camera 1.

Note that the relative positional accuracy of the electrodes on the semiconductor element 18 is formed with high precision, so once the positions of about two electrodes are recognized and the relative positional relationship with the mounting board is determined, the rest is done using a computer. If the positional information of the electrode pattern stored in the memory 17 is read out, the positional information is corrected for the relative positional relationship with the mounting board, and the X-Y table 24° bonding table 10 is controlled, the semiconductor Wire bonding of electrodes onto element 18 can be performed.

As explained above, the present invention uses a line sensor to recognize the positions of all the leads and performs wire bonding at the center positions of the 1111 points, so the accuracy of lead width and lead spacing is very high.

A fully automatic wire bonder that performs wire bonding regardless of the number of lead pins can be realized.

What's more, by using the line sensor, the field of view in one direction is four times that of the TV left camera.

Compared to two-dimensional image processing, -dimensional image processing! Since only 6 operations are required, the w1wIt processing can be performed at high speed with the row processing. .

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a fully automatic wire bonder according to an embodiment of the present invention, and FIG. 2 (α) is a plan view showing the correspondence between leads on a mounting board and a 2-in sensor. Figure 2 (A) is an enlarged view of the lead in Figure II2 (α),
Figure (C) shows the signal waveform obtained from the line sensor, and Figure 2 (d) shows the signal waveform obtained from the line sensor. FIG. 3, a diagram showing signals, is a diagram showing a case where line sensors are arranged corresponding to leads on a mounting board. 1・・・・・・・・・・・・Line camera 4 ・・・・
・・・・・・・・・ Mira -5・・・・・・・・・・
...Bonding tool 7...Kuiwei lens 8...Semiconductor equipment fee 3! A*! Shi Usui EB *J,, Large, 1yf51 Figure? , 2 gardens

Claims (1)

[Claims] The wire bonding positions of all the leads on the mounting board of the semiconductor device are photographed using a line image sensor that self-scans in the width direction of the leads. recognize the position of the part,
The position of at least one of the bonding tool or the bonding table is controlled in accordance with the woven position to automatically connect the electrical connection point between the electrode on the semiconductor element of the semiconductor device and the recognized position of the lead part of the mounting board. A wire bonding method characterized by wire bonding.