IC appearance inspection: machine vision inspection content and application advantages

Date：2021-09-18 17:45:44Views：1308

With the continuous innovation of chip technology and chip packaging technology, the chip area and packaging area are developing towards smaller, lighter and thinner, the number of pins is increasing, the pin spacing is decreasing, and the difficulty of chip appearance detection is also increasing. The traditional manual detection method has been difficult to meet the high requirements of detection and can not adapt to mass production. Machine vision detection system is widely used in various fields, from medical images to remote sensing images, from industrial production detection to file processing, from nano technology to multimedia database, almost all occasions that need human vision need machine vision detection system, especially in some fields that require high or cannot be perceived by human vision, such as accurate quantitative perception The role of machine vision detection system is particularly important for the perception of dangerous scene and invisible objects.

Chip appearance defects mainly include three aspects. Machine vision detection equipment can detect these problems.

1. Defect detection of chip package, such as scratch, stain, damage, underfilling, overflow, etc.

2. Printing defect detection, such as misprint, offset, missing print, overprint, blur, tilt, displacement, hyphenation, double-layer printing, wordless die, etc.

3. Pin defect detection, such as pin missing, pin damage, pin spacing, pin width, pin bending, pin span, pin length difference, pin standing height, pin coplanarity, pin tilt, etc.

The advantages of non-contact, continuity, economy and flexibility of machine vision detection make people have a better choice. Manual detection is gradually replaced by machine vision detection, and the machine vision detection system is applied to chip detection. Take advantage of machine vision inspection:

1. Non contact

As an accurate detection equipment, machine vision detection measures the detected object by analyzing and processing the detected object image. No contact is required in the measurement process, so there is no wear and danger to the measured object, and nondestructive testing is realized.

2. Continuity

The advantages of machine vision detection system are obvious, because people are emotional and can work. It is unreliable to use people as machines. Compared with human eyes, machines not only do not fatigue, but also have consistency and repeatability that people do not have, and can operate continuously for a long time.

In addition, since there is no manual operator, there is no man-made operation change, and multiple systems can be set to operate independently.

3. Accuracy

In recent years, due to the miniaturization of chip packaging, the increase of production complexity and the continuous enhancement of productivity, coupled with the wide use of various new components, the quality and efficiency of the production line can not be guaranteed only by using human eyes in the packaging and assembly line of semiconductor chips. The speed and accuracy of detection are the bottleneck restricting the further improvement of chip productivity and quality for a long time.

How to match the speed of packaging production and realize 99.99% on-line detection has always been the most concerned problem of semiconductor manufacturers. The detection speed and accuracy is an obvious advantage of machine vision detection. The rapidly changing machine vision detection system is replacing people for full-automatic product detection.

4. Economy

With the gradual maturity of visual inspection technology and the reduction of the price of processing hardware equipment, the economy of machine vision inspection gradually appears. A machine vision inspection system can replace multiple manual inspectors. In addition, the operation and maintenance costs of machine vision detection are relatively low.

5. Scalability

The machine vision system can make various measurements. Machine vision system has better adaptability, diversity, flexibility and reconfigurability than optical and machine sensors. When the detection process needs to be changed, for the machine vision system, "tool replacement" is only to update the software, not to upgrade the expensive hardware. When the production line is reorganized, the machine vision system can often be retained and continue to be used.

Application of machine vision in surface defect detection

The application fields are very wide, mainly including iron and steel metallurgy, non-ferrous metal processing, high-precision copper strip, aluminum strip, aluminum foil, stainless steel manufacturing, electronic materials, non-woven fabrics, fabrics, glass, paper, film and other fields.

Why use a surface defect detection system? Ensure product quality, improve production process and reduce labor cost. The line scanning surface defect detection system is mainly composed of:The vision acquisition unit mainly includes linear array camera, lens, light source and image acquisition card.The system support includes: camera support, light source support, and console support.The electrical part (communication / control part) includes encoder, motion control card or PLC, and there may also be motor, etc.Others: various wires and cables, CL lines, power lines, various SMPS, lighting controllers, etc.

In summary, the basic configuration of visual appearance defect detection system mainly includes image acquisition module, image processing module, image analysis module, data management and man-machine interface module. Compared with the traditional manual inspection methods, machine vision detection of chip appearance defects has incomparable advantages compared with manual detection: fast detection speed, high detection accuracy, high detection efficiency, low misjudgment rate, more objective and reliable, and non-contact detection will not cause contact damage to the chip.