CN202485627U - Three-dimensional detection apparatus for integrated circuit pin - Google Patents

Abstract

The utility model discloses a three-dimensional detection device for integrated circuit pins, which comprises image acquisition units (2, 3), a plane reflector (4), a light source (5), a reflector (6) and an image detection processing unit (1) , the chip (8) to be detected is set under the reflector (6), the light beam emitted by the light source (5) is reflected by the reflector (6) and irradiated on the chip (8) to be detected, and then passed through the plane reflector (4) After launching, it is incident on the image acquisition unit (2, 3), the image acquisition unit (2, 3) is connected with the image detection processing unit (1), and the image acquisition unit (2, 3) acquires the chip to be detected ( 8) is sent to the image detection processing unit (1), and after processing, the three-dimensional detection of the chip pins can be realized. The utility model can automatically detect the missing, broken, width, distance, stack height and other shape geometry key parameter information of chip pins and determine whether the chip is qualified.

Description

Integrated circuit pin three-dimensional detection device

technical field

The utility model relates to the field of integrated circuit chip detection, in particular to a three-dimensional detection device and method for integrated circuit pins, which can detect key geometrical parameters such as pin width, spacing, missing, breakage, stack height, etc., and judge whether the chip is qualified. It is very good for testing the key geometric parameters of the square flat package (Plastic Quad Flat Package, referred to as QFP) chip. the

Background technique

Integrated circuit chips (IC) need to be inspected to ensure their quality after the packaging process is completed; and the three-dimensional appearance inspection of the packaged chip pins is an important part of the packaged chip inspection process. If only the electrical performance of the packaged chip is tested and the appearance inspection is neglected, chips with qualified electrical performance but defective appearance may be output, which will inevitably lead to a decline in the product qualification rate and affect the product brand. the

Traditionally, the appearance inspection of packaged chips is usually carried out by manual visual inspection, but this method obviously has the defects of low efficiency, poor reliability and high labor cost. In order to change this backward traditional detection method, my country has invested heavily in the development of automatic detection equipment for the appearance of packaged chips. At present, appearance inspection devices based on computers and related image processing algorithms are more and more widely used in industrial fields. The device is composed of a computer, image acquisition equipment and corresponding software; the image acquisition equipment obtains the appearance image of the object, and the software processes the image through relevant image processing algorithms to obtain relevant parameters to complete the detection task. The device can replace the manual detection method, and complete the appearance detection of packaged chips with high speed, high efficiency and high accuracy. the

The pin spacing of the packaged chip realized by QFP packaging technology is very small, and the pins are very thin. Generally, large-scale or very large-scale integrated circuits adopt this packaging form, and the number of pins is generally more than 100. This technology is easy to operate and has high reliability when packaging chips; and its package size is small, the parasitic parameters are reduced, and it is suitable for high-frequency applications; this technology is mainly suitable for mounting and wiring on PCBs with surface mount technology (SMT). the

QFP packaging technology is one of the surface mount technologies. The pins are led out from the four sides in a seagull-wing (L) shape; the center distance of the pins is 1.0mm, 0.8mm, 0.65mm, 0.5mm, 0.4mm, 0.3mm, etc. kinds of specifications. For a QFP chip with a qualified appearance, there are strict requirements on the key parameters of the appearance such as the width, pitch, curvature, and stack height of the pins, and the difference from the standard value must be within the allowable tolerance range. the

The existing appearance inspection devices based on computer vision technology have problems such as low precision, poor stability, long time consumption, and poor software performance, and cannot meet the high-speed, high-precision, stable and reliable development requirements of chip packaging technology. the

Utility model content

The purpose of the utility model is to overcome the shortcomings and deficiencies of the prior art, and provide a three-dimensional detection device for integrated circuit pins, which can detect the appearance of the pins through the three-dimensional appearance detection software system of integrated circuit pins, and has the advantages of simple operation, High-speed high-precision, stable and reliable features. the

The purpose of the utility model is also to provide a method for detecting the three-dimensional appearance of integrated circuit pins realized by the above-mentioned device.

The purpose of this utility model is realized by following scheme:

A three-dimensional detection device for integrated circuit pins, including an image acquisition unit, a plane reflector, a light source, a reflector and an image detection processing unit, the chip to be detected is arranged under the reflector, and the light beam emitted by the light source is reflected by the reflector It is irradiated on the chip to be detected, and then incident to the image acquisition unit after being emitted by a plane mirror. The image acquisition unit is connected with the image detection processing unit, and the image acquisition unit acquires the image of the chip to be detected and transmits it to the image detection processing unit , after processing, the three-dimensional detection of chip pins can be realized. the

Compared with the prior art, the utility model has the following advantages:

(1) It can automatically detect the three-dimensional appearance of the pins of the integrated circuit, and the operation is simple, the detection system is stable, the efficiency is high, and the precision is high. the

(2) The detection system has three operating modes, namely, automatic detection mode, manual online detection mode and manual offline detection mode, and users can choose the system operation mode according to their needs. the

Description of drawings

Fig. 1 is a schematic structural diagram of an integrated circuit pin three-dimensional appearance inspection device. the

Fig. 2 is a schematic structural diagram of the detection module. the

Figure 3 is a detection flow chart of the detection module. the

Fig. 4 is a flow chart for judging missing pins. the

Figure 5 is a schematic diagram of the optical path. the

In the figure: 1 PC; 2CCD camera; 3 lens; 4 four flat mirrors distributed around; 5 light source; 6 reflector; 8 chip to be tested. the

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail. the

As shown in Figure 1, the three-dimensional detection device of the integrated circuit pin of the utility model includes an image acquisition unit, a plane mirror 4, a light source 5, a reflector 6 and an image detection processing unit 1, and the chip 8 to be detected is arranged on the reflector 6 Below, the light beam emitted by the light source 5 is reflected by the reflector 6 and irradiated on the chip 8 to be detected, and then emitted by the plane mirror 4 and then incident on the image acquisition unit, which is connected with the image detection processing unit 1, The image acquisition unit acquires the image of the chip 8 to be inspected, and transmits it to the image inspection processing unit 1, and after processing, the three-dimensional inspection of the pins of the chip can be realized. the

As shown in FIG. 2 , the image detection processing unit 1 includes a camera control module 11 , an image calibration module 12 and an image detection module 14 . the

The camera control module 11 is used for the image acquisition unit, including an external trigger image acquisition mode and a continuous image acquisition mode, to complete image acquisition and send an image acquisition completion signal to the system. the

The image calibration module 12 mainly realizes the functions of making, saving and loading calibration files, and corrects the images. the

The image detection module 14 realizes the detection function of key parameters of all pins and determines whether the chip is qualified, and saves the detection results. The detected pin parameters include two-dimensional parameters (missing, breakage, width, spacing, deviation, curvature, span, row bending, inclination, etc.) and three-dimensional parameters (stack height, coplanarity, etc.) and key parameters of shape geometry. the

The image detection processing unit 1 of the appearance detection device of the present invention may further include a parameter management module 13 and a result statistics module 15 . The parameter management module 13 mainly implements functions such as editing, modifying, saving to disk and acquiring parameters of pin parameters. The main function of the result statistics module 15 is to generate 5 kinds of reports: product summary report, single batch summary report, product statistics, single batch statistics, index statistics; and display, save, delete and print each report. the

The work of the image detection processing unit 1 includes the following steps: first enter the calibration module 12, calibrate the camera and save the calibration file; then enter the parameter management module 13, select the chip model to be detected and set the corresponding standard parameter value and allowable tolerance value; Send a signal to control the CCD camera to take pictures, and display the images on the interface in real time; process and analyze the collected images through the detection module 14, and save the detection results in the database; compare with the standard value, judge according to the allowable tolerance value Whether the chip is qualified. the

The working modes of image detection processing unit 1 include automatic detection mode, manual online detection mode and manual offline detection mode: automatic detection mode is that the detection device works as a module in the chip automatic detection and sorting system, and can communicate with other modules and coordinate Complete the work of chip detection and sorting out qualified products; the manual online detection mode is for the detection device to work independently, the detection software system controls the CCD camera to collect pictures, and then processes the images to obtain the detection results; the manual offline detection mode is similar to manual online detection mode, but the picture comes from disk. the

As shown in FIG. 3 , the detection flowchart of the pin detection module, the pin detection module is the core module for implementing the image detection processing unit of the integrated circuit pin three-dimensional detection device. Its process includes the following steps:

(1) Correct image distortion according to calibration;

(2) Perform edge detection on the collected images, and find the angle between the bottom view and the camera coordinate system in the horizontal plane;

(3) Image segmentation intercepts the bottom view and rotates the bottom view according to the included angle, and aligns the image relative to the camera coordinate system in the horizontal plane;

(4) Edge extraction, obtain the detection reference in the bottom view and four side views, the reference is the center point of each side of the chip substrate, and load the detection frame of each pin area according to the reference;

(5) Detection of pin width and spacing: edge extraction, obtaining the edge position of the pin stripe and the midpoint position between the edges, the edge spacing of the stripe is the pin width of the detected chip, and the midpoint between adjacent stripes The distance is the pin spacing, and the detection results are recorded in an array, and the length of the array corresponds to the number of pins of the detected chip; 

(6) Calculate the missing pins according to the pin spacing, including the position of missing pins and the number of missing pins;

(7) Rearrange the width and spacing according to the pin missing information so that it corresponds to the actual position of the pin, and set its value to 0 for the missing position;

(8) Edge extraction to obtain the pin stripe area, obtain the coordinate position of the middle of each pin, the position of the end of each pin according to the edge of the stripe, rearrange the data according to the missing information, and calculate the curvature;

(9) Detect the position of the end of each pin in each side view, and the midpoint position of the white stripe of each pin area in the side view, and rearrange the data according to the missing information; the coordinates of these midpoints are obtained by the least square method Fit a straight line, and use the straight line as a baseline to find the length of the pin in the side view;

(10) Calculate the deviation, coplanarity, span, row bend, and inclination through the coordinates of the midpoint of each pin end in the bottom view; calculate the stack height according to the length of the pins in the side view;

(11) Determine whether the chip is qualified according to the test result. the

As shown in FIG. 4 , the pin missing judgment flow chart mainly obtains pin missing information such as chip missing pin position index and missing quantity. The steps mainly include:

(1) Compare the number of detected pins with the number of standard pins to determine the total number of missing pins;

(2) Judgment of the absence of the head end is based on the difference between the detected distance d from the head position of the pin to the side reference and the theoretical value D of the distance in the chip parameters. Then the number of missing pins at the first position is:

k=[d/D+0.5];

(3) According to the standard pin spacing P and the pin spacing P[i] at a certain position in the middle, the number of missing pins is calculated as: k=[P[i]/P+0.5]-1;

(4) If there are missing pins at the end, the missing number is the total missing number calculated in (1) minus the sum of the missing numbers calculated in (2) and (3);

(5) When calculating the missing number, record the index of each missing position sequentially, and save the missing information in the result. the

As shown in Figure 5, the method of calculating the stack height according to the length of the pins in the side view in step (10) described in the detection process of the pin detection module is:

Stoff represents the stack height (a parameter to be calculated for the chip); slead represents the length of the pin in the side view (a parameter obtained by image processing); fb represents the distance from the end of the pin to the chip substrate (a known parameter of the chip); θ represents the incident The angle between the light and the horizontal line is a parameter value determined during the optical path design; the calculation formula is:

Stoff = slead/cosθ-fb*tanθ. the

The utility model can replace the traditional manual detection method, overcome the shortcomings of the existing integrated circuit packaging chip detection technology, realize automatic, stable, high-speed and high-precision pin detection technology, and greatly improve the efficiency. the

Claims (1)

1. an ic pin three-dimensional detection device is characterized in that, comprises image acquisition units (2; 3), plane mirror (4), light source (5), reflector (6) and image detection processing unit (1), chip to be detected (8) is arranged on reflector (6) below, the light beam that said light source (5) sends is radiated on the chip to be detected (8) after reflector (6) reflection; After plane mirror (4) emission, incide image acquisition units (2 again; 3), this image acquisition units (2,3) is connected with image detection processing unit (1); Image acquisition units (2; 3) gather the image that obtains chip (8) to be detected, be sent to image detection processing unit (1), can realize after treatment the three-dimensional of chip pin is detected.

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