JPH06244600A - Inspection equipment for integrated circuit chip levitation - Google Patents

Abstract

PURPOSE:To automatically inspect the rise of an integrated circuit chip above a lead frame in a die bonding process, and quantitatively manage the levitation amount. CONSTITUTION:In order to inspect the rise of a bonded integrated circuit chip 2 above a lead frame 1, at least a pair of plane mirrors 11 are so arranged that inclined reflecting mirrors face each other while putting the chip 2 between them. An illuminator 5 is arranged so as to face one plane mirror, and a camera 4 is arranged so as to face the other plane mirror. The light cast from the illuminator 5 is reflected by the one plane mirror, and illuminates the integrated circuit chip 2 from the side direction. The image of the chip 2 is picked up by the camera 4. From the heights of at least two points of the image, the rise of the integrated circuit chips 2 above the lead frame 1 is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated circuit chip floating inspection device for inspecting an amount of floating of an integrated circuit chip adhered on a lead frame from the lead frame.

[0002]

2. Description of the Related Art Generally, an integrated circuit chip (bare chip) cut out from an integrated circuit wafer by a die bonder.
Mounted on a lead frame coated with adhesive resin,
In the die bonding process of bonding with the bonding resin interposed between the lead frame and the integrated circuit chip, the floating of the integrated circuit chip with respect to the lead frame becomes a problem. 4 shows a place where the integrated circuit chip 2 is mounted on the lead frame 1 by a die bonder, and FIG. 5 shows a case where the integrated circuit chip 2 is properly adhered to the lead frame 1 and the floating amount is substantially zero. FIG. 6 shows a state in which the adhesive resin 3 between the lead frame 1 and the integrated circuit chip 2 is unevenly distributed, and the lift amount Z exceeds the allowable range and becomes excessive.

Due to the floating problem of the integrated circuit chip 2 described above, the integrated circuit chip 2 with respect to the lead frame 1 is processed before the post-process such as the wire bonding process is performed.
It is necessary to inspect whether the floating amount of is within the allowable range. Conventionally, the inspection of the lifted amount of the integrated circuit chip in the die bonding process has been performed visually by an inspector.

[0004]

By the way, the visual inspection by the inspector has a problem that there is a limit to the improvement of the inspection efficiency and it is difficult to quantitatively control the floating amount of the integrated circuit chip. In view of the above points, the present invention provides an integrated circuit chip lift inspection device that enables automation of lift amount inspection from a lead frame of an integrated circuit chip in a die bonding process and that enables quantitative management of the lift amount. The purpose is to provide.

[0005]

In order to achieve the above-mentioned object, the integrated circuit chip lift inspection apparatus of the present invention is used for inspecting the lift amount of an integrated circuit chip bonded on a lead frame from the lead frame. In the above, at least a pair of reflecting mirrors are arranged on both sides of the integrated circuit chip so that inclined reflecting surfaces sandwiching the integrated circuit chip face each other, and one reflecting mirror of one of the pair of reflecting mirrors is provided. The imaging means is arranged so that the illuminating means is opposed to the other reflecting mirror, and the light emitted from the illuminating means is reflected by the one reflecting mirror to illuminate the integrated circuit from the side. Means captures an image of the integrated circuit chip, and the image of the integrated circuit chip is picked up from at least two positions of the image portion corresponding to the upper side of the integrated circuit chip. It is configured to detect the floating amount of the lead frame.

[0006]

In the apparatus for inspecting the lift of the integrated circuit chip of the present invention, by devising the arrangement of the reflecting mirrors, the light emitted from the illuminating means is reflected by one reflecting mirror to illuminate the integrated circuit chip from the side. Then, the image of the integrated circuit chip can be accurately taken by the imaging means. Then, by detecting the positions of at least two points of the image portion corresponding to the upper side of the integrated circuit chip by image processing, the amount of lift of the integrated circuit chip from the lead frame can be recognized, and the amount of lift is within an allowable range. It can be determined whether or not it is within.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an integrated circuit chip floating inspection device according to the present invention will be described below with reference to the drawings.

In FIG. 1, an object to be inspected is one in which an integrated circuit chip (bare chip) 2 is placed on a lead frame 1 and bonded with an adhesive resin. The television camera 4 as the image pickup means and the illuminator 5 as the lighting means face downward on the rotary stage 6 supported so as to rotate in a horizontal plane above the object to be inspected, that is, the lead frame 1 and the integrated circuit chip 2. Is attached to. A reflector 10 is arranged so as to surround the integrated circuit chip 2 in order to measure the amount of lift of the integrated circuit chip 2 from the lead frame 1 as viewed from the side of the integrated circuit chip 2.

As shown in FIG. 2, the reflector 10 is formed by combining four plane mirrors (completely reflecting plane mirrors) 11 so as to form a regular quadrangular pyramid-shaped concave surface so that the reflecting surfaces face each other in an inclined state. The reflecting surface of each plane mirror 11 forms an angle slightly larger than 45 degrees with the upper surface of the lead frame.

At the time of measurement, the illuminator 5 is located directly above one of the pair of plane mirrors 11 that face each other with the integrated circuit chip 2 in between, and the television camera 4 is located directly above the other. The video signal output from the television camera 4 is input to the image processing device 20.

The rotary stage 6 is movable in X, Y and Z directions and has a rotation center S. Therefore,
By rotating the stage 6 every 90 degrees, the TV camera 4
Can sequentially capture images reflected by the four plane mirrors 11. The reflector 10 is supported by the up-and-down means so as not to interfere with the conveyance of the object to be inspected at the raised position except during measurement.

In the structure of this embodiment, the light emitted downward from the illuminator 5 is reflected by one of the plane mirrors 11 in the lateral direction along the lead frame 1 and becomes the transmitted light passing through the integrated circuit chip 2. The transmitted light is further reflected by the other plane mirror 11 and travels in the direction coaxial with the optical axis R of the television camera 4 (upward). As a result, the television camera 4 can accurately capture an image of the integrated circuit chip 2 and its periphery illuminated by the transmitted light in the lateral direction. At that time, each plane mirror 1
Since the reflection surface of No. 1 makes an angle of slightly larger than 45 degrees with respect to the upper surface of the lead frame, light passing through the lower part of the integrated circuit chip 2 can also be generated and the image under the integrated circuit chip 2 is also good. Can be taken into. In the image processing device 20, the image signal Q1 of the integrated circuit chip 2 on the lead frame 1 is processed as shown in FIGS. ，
Q2 can be recognized, and the distances a, b and | a−b | from the known upper side of the camera visual field to the upper sides of the images Q1 and Q2 corresponding to the upper side of the integrated circuit chip 2 can be measured in advance.

The determination of the amount of floating using the distances a and b is, for example, when the distances a and b are both above a certain value (the amount of floating above the lead frame 1 is within a certain value), |
It can be determined by whether or not ab | is within a certain value (the inclination of the integrated circuit chip is less than a certain angle). Figure 3
(A) is a distance a <b, and the distance a is too small. In other words, the lift amount of the integrated circuit chip 2 with reference to the upper surface of the lead frame 1 is excessive beyond the allowable range, and the die bonding is defective. Is shown. Further, FIG. 3B shows a distance a≈b, and both distances a and b are proper values. In other words, the floating amount of the integrated circuit chip 2 with the upper surface of the lead frame 1 as a reference is within an allowable range. Yes, it indicates that the die bonding is good.

The measurement of the amount of floating and the quality judgment are as follows.
By rotating the rotating stage 6 every 90 degrees, the four side surfaces of the integrated circuit chip 2 can be sequentially performed, and the lift amount is measured on all the four side surfaces, and the quality determination is performed, and then the final quality determination is performed. You can That is,
Those that are determined to be defective on one side are finally determined to be defective even if they are determined to be non-defective in the measurement of the other side.

Although the embodiment of the present invention has been described above, it is obvious to those skilled in the art that the present invention is not limited to this and various modifications and changes can be made within the scope of the claims. Let's do it.

[0016]

As described above, according to the integrated circuit chip floating inspection apparatus of the present invention, the amount of floating of the integrated circuit chip from the lead frame can be accurately recognized by devising the arrangement of the reflecting mirror. As a result, the inspection after the die bonding process can be automated, and the labor of the visual inspection personnel can be reduced. Further, by feeding back the inspection result to the die bonder that executes the die bonding process, it is possible to improve the quality of the product.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an integrated circuit chip floating inspection device according to the present invention.

FIG. 2 is a plan view of a reflector used in an example.

FIG. 3 is an explanatory diagram showing an example of an image of an integrated circuit chip.

FIG. 4 is a plan view showing a place where an integrated circuit chip is mounted on a lead frame by a die bonding process.

FIG. 5 is a side view showing a case where an integrated circuit chip is mounted on a lead frame and a floating amount is substantially zero.

FIG. 6 is a side view showing a case where an integrated circuit chip is mounted on a lead frame and the amount of floating is excessive.

[Explanation of symbols]

 1 Lead Frame 2 Integrated Circuit Chip 3 Adhesive Resin 4 TV Camera 5 Illuminator 6 Rotating Stage 10 Reflector 11 Plane Mirror 20 Image Processing Device Q1, Q2 Image

Claims (1)

[Claims] 1. An integrated circuit chip lift inspection device for inspecting a lift amount of an integrated circuit chip adhered on a lead frame from the lead frame, wherein the integrated circuit chip is tilted on both sides of the integrated circuit chip. At least a pair of reflecting mirrors are arranged so that the reflecting surfaces face each other, and the illuminating means is arranged facing one of the pair of reflecting mirrors, and the imaging means is arranged facing the other reflecting mirror. Then, the light emitted from the illuminating means is reflected by one of the reflecting mirrors to illuminate the integrated circuit chip from the side, and the image pickup means captures an image of the integrated circuit chip. The floating amount of the integrated circuit chip from the lead frame is detected from the positions of at least two points in the image portion corresponding to the upper side of the. Integrated circuit chip floating inspection device.