JPH05232034A - External appearance inspecting device and method for semiconductor element - Google Patents

Abstract

PURPOSE:To provide an external appearance inspecting device and a method thereof for semiconductor elements by which an inspecting time can be shortened without complicating the inspecting device. CONSTITUTION:An external appearance inspecting device and a method thereof for semiconductor elements are composed of a CCD camera 2 arranged above a continuous lead frame 1, an image processing device 3 connected to the CCD camera 2 and a data processing device 4 connected to the image processing device 3, and a grouped semiconductor element 10 is observed/read simultaneously by means of the CCD camera 2, and is converted into an image. Next, the quality of individual semiconductor elements 10 is discriminated by means of the image processing device 3 according to this read image, and information formed of the discrimination on this quality are stored with the respective grouped semiconductor elements 10 existing in the same image as the read image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual inspection apparatus for observing semiconductor elements mounted in multiple rows on a continuous lead frame by an optical reading apparatus to determine whether they are defective or not, and a method therefor.

[0002]

2. Description of the Related Art To manufacture a semiconductor device using a continuous lead frame, first mount a semiconductor chip on a die pad of the lead frame, wire the semiconductor chip and an inner lead with a bonding wire, and It is integrally sealed with molding resin. As a result, the semiconductor elements are mounted in multiple rows on the lead frame. After going through the process of integral sealing with mold resin,
While the semiconductor element is still mounted on the lead frame, appearance inspection for cracks and holes on the surface of the mold resin, and bending and bending of the outer leads is performed.

An optical microscope or an optical reading device such as a CCD (solid-state image pickup device) camera is used as a device for inspecting the appearance of the semiconductor element, and the appearance is visually inspected by human eyes to determine whether the semiconductor element is good or bad. The judgment was made one by one. In addition, the appearance inspection method using image processing is
First, the appearance of one semiconductor element mounted on the lead frame is read using one CCD camera and converted into a read image. Next, the read image is subjected to image processing by the image processing device, and a predetermined inspection item is inspected.
Then, the quality of the semiconductor element on the lead frame is determined by comparing the result of this inspection with a predetermined reference value. By this pass / fail judgment, the rejected semiconductor element is separated from the lead frame, while the rejected semiconductor element is sent to the next step while being mounted on the lead frame.

In these appearance inspection methods, one CCD is used.
In order to read the external appearance of one semiconductor element with a camera or optical microscope, if multiple rows of semiconductor elements are mounted in the transport direction of the lead frame, CCs for the number of rows are mounted.
Prepare a D camera, etc., or move the CCD camera and the lead frame to change the semiconductor device to be inspected to C
I read the appearance according to the view of the CD camera.

[0005]

However, the above appearance inspection method has the following problems. That is, in visual inspection by human eyes using an optical microscope or CCD camera, variations in judgment due to individual differences or physical conditions are likely to occur. Further, in any of the appearance inspection methods, in order to reduce the inspection time for determining the quality of the semiconductor element,
It is necessary to increase the number of optical microscopes and CCD cameras. Further, in the case of inspecting a plurality of inspection items, more CCD cameras and the like are required, which leads to complication of the inspection device. Therefore, it is an object of the present invention to provide a semiconductor device appearance inspection apparatus and method capable of shortening the inspection time without complicating the inspection apparatus.

[0006]

SUMMARY OF THE INVENTION The present invention is an apparatus and method for inspecting the appearance of a semiconductor device, which has been made to solve the above problems. That is, this appearance inspection apparatus is for inspecting the appearance of semiconductor elements mounted in multiple rows on a continuous lead frame, and is an optical reading apparatus for simultaneously observing a group of semiconductor elements on a lead frame. An image processing device, which is provided above and connected to the optical reading device for determining the quality of the semiconductor element based on the image read from the optical reading device, stores the information file including the determination of the quality. The processing device is connected to the image processing device.

Further, the appearance of the semiconductor elements mounted in multiple rows on a continuous lead frame is observed using an optical reading device, and based on the read image obtained by this observation, the semiconductor elements of a predetermined inspection item are checked. In the appearance inspection method for determining pass / fail, a group of semiconductor elements are simultaneously observed by an optical reading device and converted into a read image,
Then, by processing the read image,
The quality of each semiconductor element is determined, and information including the determination of quality is stored for each group of semiconductor elements in the same image as the read image.

[0008]

The appearance of a group of semiconductor elements is read at the same time by one optical reading device, and the read image is processed by the image processing device to determine the quality of each semiconductor device. Further, by storing the information of the quality judgment for each group of semiconductor elements of the same read image, it is possible to collectively carry out the subsequent steps such as the step of cutting off the defective semiconductor elements from the lead frame. Especially,
In the case of inspecting a plurality of inspection items, the above-mentioned steps can be collectively processed by synthesizing the quality information obtained for each inspection item in each group.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor device appearance inspection apparatus and method according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view for explaining a semiconductor device appearance inspection apparatus of the present invention, and FIG. 2 is a schematic view for explaining storage of semiconductor device quality determination information.
First, the configuration of the appearance inspection apparatus for semiconductor elements will be described with reference to FIG. That is, the semiconductor elements 10 to be subjected to the visual inspection are mounted in multiple rows on the continuous lead frame 1 and are sequentially transported together with the lead frame 1.
This semiconductor element 10 is obtained by integrally sealing a semiconductor chip (not shown) connected on the die pad of the lead frame 1 with a molding resin. An optical reading device including a CCD camera 2 is provided above the lead frame 1, and takes in an external image of the semiconductor element 10 and converts it into a read image. It should be noted that the transport mechanism (not shown) of the lead frame 1 must have sufficient positioning accuracy so that the CCD camera 2 can reliably obtain an image of the group of semiconductor elements 10.

An image processing device 3 is connected to the CCD camera 2, and the read image output from the CCD camera 2 is sent to the image processing device 3. The read image is subjected to image processing to perform a predetermined inspection. Further, the data processing device 4 is connected to the image processing device 3, and the pass / fail information determined by the image processing device 3 is stored in the information file set in the data processing device 4. The data output from the data processing device 4 controls the operation of the device used in the subsequent process.

Next, a method for inspecting the appearance of a semiconductor device using this appearance inspection apparatus will be described. First, a group of semiconductor elements 10 mounted on the lead frame 1 (for example,
The whole of 10a to 10h) is set as the inspection area 21, and an image of the entire inspection area 21 is captured by the CCD camera 2 to obtain a read image.

Then, the read image in which the appearance image of each of the group of semiconductor elements 10 is captured is used as the image processing apparatus 3.
Send to. In the image processing device 3, the read image is divided for each semiconductor element 10. For example, 10a to 10h
When all of the eight external appearances are captured, the read image is divided into individual semiconductor element 10 regions, and a predetermined inspection is performed for each region.

The items of the appearance inspection are the outer dimensions of the mold resin and the presence or absence of peeling, stains, chips, scratches and cracks on the surface of the mold resin, the outer diameter of the leads, discoloration, misalignment between the leads and the mold resin, and the remaining gate. Etc. For example, when inspecting the outer dimension of the mold resin, the outer dimension of the mold resin obtained from the read image is compared with the outer dimension of the mold resin stored in the image processing apparatus 3 in advance, and the difference is used as a reference. Determine if the value is exceeded. Based on the reference value preset in this way,
The quality of each semiconductor element 10 is determined. That is,
Eight semiconductor devices (10a-
10 h) pass / fail judgment information is obtained.

The pass / fail judgment information is sent to the data processing device 4 and stored in the information file 41 as shown in FIG. In one information file 41, the determination information of the quality of the semiconductor element for each group (for example, eight) obtained from one read image is accumulated in a state corresponding to the positional relationship of the lead frame 1, for example. In the information file 41 of FIG. 2, the mark “◯” represents good and the mark “X” represents information of no. This information file 41 is created for each inspection area 21 taken in by the CCD camera 2 and sequentially accumulated in the band-shaped file 42.

That is, every time one information file 41 is created, the lead frame 1 is conveyed to the next inspection area 21 by a predetermined amount and this inspection is repeated, and the new information file 41 created is transferred by a predetermined amount of address. (Strip file 42
(Data address in) is stored in the shifted band-shaped file 42. By repeating this, the band-shaped file 42
In the table, determination information of pass / fail is continuously stored in a state corresponding to each inspection area 21.

Further, the data processing device 4 controls the next device on the basis of the quality determination information of each semiconductor element 10 stored in the information file 41. For example, the data processing device 4 sends to the next device a control signal necessary for the work of cutting off the semiconductor element 10 (10c, 10f in FIG. 2) determined to be no from the lead frame 1. After this work is completed, the pass / fail judgment information stored in the information file 41 is no longer necessary. Therefore, the storage amount of the information file 41 can be reduced by deleting it. By using such an appearance inspection method, it becomes possible to collectively perform the work of the post-process, and the processing time can be shortened.

Next, another embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a perspective view illustrating another embodiment of the present invention,
FIG. 4 is a schematic diagram illustrating storage of discrimination information according to another embodiment. As shown in FIG. 3, as an apparatus for visual inspection,
Two optical reading devices, a first CCD camera 2A and a second CCD camera 2B, are provided. For example, the first C
A group (first inspection region 21A) of the front surface side of the semiconductor element 10 is observed by the CD camera 2A, and image processing is performed by the first image processing apparatus 3A to determine pass / fail. One second CCD
A group (second inspection region 21B) of the back surface side of the semiconductor element 10 is observed by the camera 2B, and image processing is performed by the second image processing device 3B to determine pass / fail.

Next, these image processing devices 3A, 3B
In response to the pass / fail judgment result obtained in step 1, the data processing device 4 creates the first information file 41A and the second information file 41B as shown in FIG. The second information file 41B is sequentially stored in the file 42A and the second band-shaped file 42B. Then, the first information file 41A stored in the first strip-shaped file 42A and the second information file 41A stored in the second strip-shaped file 42B.
The same group of semiconductor elements 1 in the information file 41B
The determination information of pass / fail of 0 is synthesized with each other to create a synthesis file 43. That is, the first information file 41
The pass / fail judgment information stored in A and the second information file 4
If either one of the pass / fail determination information stored in 1B has the determination information (x), the determination result is written in the composite file 43. Then, the data processing device 4 controls the next device based on the quality determination information of the composite file 43.

As described above, by synthesizing the band-shaped files 42 to create the composite file 43, the post-process work can be collectively processed even when a plurality of image processing devices 3 are used. Becomes In the above embodiment, the case where the front surface group and the back surface group of the semiconductor element 10 are inspected has been described, but the present invention is not limited to this, and the front surface plural groups and the back surface plural groups are inspected. You can adapt even if you do. In this case, the CCD camera 2 and the image processing device 3 are prepared by the respective numbers of groups, the information file 41 and the band-shaped file 42 corresponding to them are created, and the band-shaped files 42 are combined to form the combined file 43. Get it. The present invention can also be applied to the case where the first lead frame 1A and the second lead frame 2B are arranged in parallel as shown in FIG. That is,
If the inspection area 21 is the entire direction in which the first lead frame 1A and the second lead frame 1B are arranged, the CCD camera 2
A plurality of semiconductor elements 10 sequentially transported without increasing the number
The image of can be captured in a short time.

[0020]

As described above, the semiconductor device appearance inspection apparatus and method according to the present invention have the following effects. That is, if the semiconductor element appearance inspection apparatus of the present invention is used, it is possible to determine whether the quality is good or not without human eyes, so that it is possible to always make a quantitative determination. Further, according to this appearance inspection method, the appearance of a group of semiconductor elements is simultaneously read by one CCD camera, and the quality of each semiconductor element is determined by image processing, which complicates the apparatus. Therefore, the determination process can be performed in a short time. Furthermore, in the case of inspecting a plurality of inspection items, after obtaining the determination information of pass / fail for each inspection item,
By combining these pieces of quality determination information among the respective groups, it is possible to collectively perform the work in the post-process, so that the processing time can be significantly shortened. Therefore, in appearance inspection that requires many inspection items,
The present invention is particularly effective.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating an appearance inspection device of the present invention.

FIG. 2 is a schematic diagram illustrating storage of quality determination information in the data processing device.

FIG. 3 is a perspective view illustrating another embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating storage of quality determination information according to another embodiment.

FIG. 5 is a perspective view illustrating another inspection area.

[Explanation of symbols]

 1 lead frame 2 CCD camera 3 image processing device 4 data processing device 10 semiconductor element 21 inspection area 41 information file 42 strip-shaped file 43 composite file

Claims (2)

[Claims] 1. A semiconductor device appearance inspection apparatus for inspecting the appearance of semiconductor devices mounted in multiple rows on a continuous lead frame, wherein a group of the semiconductor devices is provided above the lead frame and observed simultaneously. An optical reading device, an image processing device that is connected to the optical reading device, and determines whether the semiconductor element is good or bad based on an image read from the optical reading device, and is connected to the image processing device and is good or bad. And a data processing device in which an information file formed by the above determination is stored. 2. The appearance of the semiconductor elements mounted in multiple rows on a continuous lead frame is observed by using an optical reading device, and based on the read image obtained by the observation,
In an appearance inspection method for determining the quality of the semiconductor element with respect to a predetermined inspection item, a group of the semiconductor elements are simultaneously observed by the optical reading device to be converted into a read image, and then the read image is image-processed. By
A visual inspection method, characterized in that the quality of each of the semiconductor elements is determined, and then information comprising the determination of the quality is stored for each of the group of semiconductor elements in the same image as the read image.