JPH02205039A - Mounting method for semiconductor pellet - Google Patents

Abstract

PURPOSE:To maintain a wire length in a wire bonding of next step constant, to shorten characteristic regulating time and to further eliminate characteristic malfunction by recognizing a bonding pad of a semiconductor pellet, and mounting it at the pad position as a reference. CONSTITUTION:A X-Y-theta-Z moving table 1 is moved in an XY-axis direction, a first recognition bonding pad 6 of a semiconductor pellet 4 is displayed on a monitor 5 by a camera 3, the brightness and darkness of the pad and the periphery are recognized as a binary image by a recognition unit 2, and the position of the pad 6 is detected. Then, a second recognition bonding pad 7 is similarly detected, deviations of X, Y, theta to a reference mounting position are calculated, the deviations are corrected by the table 1, and the pellet 4 is mounted on the mounting land of a lead frame.

Description

[Detailed Description of the Invention] [Field of Industrial Application] Conventionally, this type of semiconductor pellet mounting method has been used to mount semiconductor pellets that are imaged on a monitor 5 by a camera, as shown in the semiconductor pellet monitor screen diagram in FIG. 4
The external image of the pellet is captured as a binary image of brightness and darkness that separates the inside and outside of the pellet. After the recognition device detects the amount of deviation from the standard mount position, the position is corrected using the X-Y-θ-2 moving table k, and the semiconductor Stem pellet 4 (
It was designed to be mounted on a mounting land such as a ceramic package (ceramic package) or a lead frame.

[Problem to be solved by the invention]

The conventional semiconductor pellet mounting method described above recognizes the external shape of the semiconductor pellet 4 and positions it as shown in FIG. The dimensions of the bonding pad on the stem side are the sum of the mechanical accuracy of the mounting device, the recognition accuracy, and the accuracy of the position of the bonding pad with respect to the external shape of the semiconductor pellet]X and Y.

This causes variations in the wire length in the next step of wire bonding, and particularly in high-frequency semiconductor devices, it takes time to adjust the characteristics, and there are disadvantages in that characteristic defects occur.

[Means to solve the problem]

The present invention provides a semiconductor pellet mounting method in which the amount of deviation of a semiconductor pellet from a reference mounting position is detected, the mounting position is corrected, and the pellet is mounted on a mounting land. This is a semiconductor pellet mounting method in which the positions of the bonding pads and the pads are respectively recognized, the positions of both bonding pads are used as reference positions of the semiconductor pellet, the amount of deviation from the mounting position is detected, and corrections are made in the X, Y, and θ directions.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a semiconductor pellet mount device used in an embodiment of the present invention, and FIGS. 2(a) and 2(b) are diagrams showing monitor screens when bonding pads are recognized.

First, move the X-Y-θ-Z moving table 1 shown in FIG.
, in the Y direction, the first recognized bonding pad 6 of the semiconductor pellet 4 is displayed on the monitor 5 by the camera 3 as shown in FIG. 2(a), and the brightness and darkness of the bonding pad and its surroundings are recognized as a binary image. Recognized by device 2 (
(pattern matching) to detect the position of the bonding pad 6. Here, FIG. 2(a) is an enlarged view of the bonding pad in the upper right portion of the semiconductor pellet 4 shown in FIG. 3. As shown in FIG.

Next, as shown in FIG. 2(b), the second recognition bonding pad 7 is also detected in the same manner as described above, and after calculating the amount of deviation in X, Y, and θ from the reference mount position, X-Y-θ-Z The displacement amount is corrected using the moving table 1, and the semiconductor pellet 4 is mounted on the mounting land of the stem or lead frame. Here, FIG. 2(b) is an enlarged view of the bonding pad at the upper left portion of the semiconductor pellet 4 shown in FIG. 3. As shown in FIG.

〔Effect of the invention〕

As explained above, the present invention recognizes the bonding pad of a semiconductor pellet and mounts the semiconductor pellet based on the position of the bonding pad, so that the bonding pad of the semiconductor pellet that has been mounted on the stem and the bonding pad on the stem side can be distinguished. Since the spacing can be made highly accurate, the wire length in the next step of wire bonding becomes constant, the characteristic adjustment time is shortened, and the occurrence of characteristic defects can be eliminated.

In addition, since there is no need to recognize the outer shape, there is no effect of recognition errors due to chipping on the outer periphery of the pellet, and the recognition accuracy is also improved.

A diagram showing a monitor screen. FIG. 3 is a diagram showing a conventional monitor screen for semiconductor pellets.

DESCRIPTION OF SYMBOLS 1... X-Y-θ-Z moving table, 2... Recognition device, 3... Camera, 4... Semiconductor pellet, 5...
・Monitor, 6...First recognition bonding pad, 7
...Second recognition bonding pad.

Claims (1)

[Claims] In a semiconductor pellet mounting method in which the amount of deviation of a semiconductor pellet from a reference mounting position is detected, the mounting position is corrected, and the pellet is mounted on a mounting land, the positions of a first recognition bonding pad and a second recognition bonding pad on a semiconductor pellet are disclosed. Recognize each,
The amount of deviation from the mounting position is detected by using the two bonding pad positions as reference positions of the semiconductor pellet,
A semiconductor pellet mounting method characterized by making corrections in the Y and θ directions.