Application of X-ray detection technology in PCBA

Date：2021-09-16 16:08:00Views：1296

How can X-ray detection technology be better applied to PCBA? First, let's understand the development of PCBA industry. With the development of high-density packaging technology, testing technology is also facing new challenges. Many new technologies are also emerging to meet new challenges. X-ray detection technology is a very important method. Through X-ray detection, the welding and assembly quality of BGA can be effectively controlled. At present, X-ray detection system is not only used for laboratory analysis, but also used in many production industries. PCBA industry is one of them. X-ray detection technology is a necessary means to ensure the quality of electronic assembly to some extent.

What is PCBA packaging?

PCBA processing process is very complex, including PCB processing, parts procurement inspection, SMT patch assembly, dip plug-in, PCBA testing and other important processes. PCBA inspection is the most critical quality control link in the whole PCBA process, which determines the final performance of the product. In short, this is the whole production process of PCB blank board on SMT and dip plug-ins.

PCBA packageinspect

The functional test of PCBA circuit board after assembly is usually called FVT (functional verification test) or FCT (functional test). The purpose is to capture the poorly assembled circuit board and install it through the analog circuit board. When assembling the whole machine, conduct full function test, and capture all defective circuit assembly boards before assembling the whole machine, so as to avoid defects found after assembling the whole machine, which must be completely removed. Reorganization will waste working time and material loss.

PCBA solder

PCBA solder: its English name is pseudosoldering, which is generally caused by solder joint oxidation or impurities, poor welding temperature and improper method. The essence is that there is an isolation layer between solder and pin. They are not in full contact. Their state is generally invisible to the naked eye. However, its electrical characteristics are not conductive or poor, which affects the circuit characteristics. The detection of X-ray detection equipment requires X-ray detection equipment.

PCBA bubble

When SMT is welded on PCBA circuit board, some bubbles will inevitably appear in BGA Solder ball. That's why it's called a solder ball hole. The industry has specified standards for the size of solder ball bubble area to ensure that defects, failures and unavailability are avoided or reduced when the product is put into use. Similarly, since defects cannot be seen directly by the naked eye, the common method for detecting PCBA bubbles is still to use X-ray detection equipment.

X-ray performance

Due to its short wavelength and high energy, X-ray is only partially absorbed by the material, mostly through the atomic gap, showing strong penetration ability. The ability of X-rays to penetrate matter is related to the energy of X-ray photons. The shorter the X-ray wavelength, the greater the photon energy and the stronger the penetration. The penetrability of X-ray is also related to the density of substances. The properties of differential absorption can be used to distinguish substances with different densities.

Relationship between X-ray testing equipment and PCBA

The main function of X-ray testing equipment is nondestructive testing of electronic components. X-ray testing equipment can carry out nondestructive testing on large and high-density printed circuit board components (PCBA and printed circuit board components) to ensure the quality of PCBA circuit board. In addition, only PCBA may have a high investment in electronic components. When a unit is finally tested, it may reach $25000. Because the cost is so high, finding and repairing assembly problems is now a more important step than in the past. Today's more complex assemblies are about 18 square inches and 18 layers. There are more than 2900 components at the top and bottom; It contains 6000 circuit nodes; There are more than 2000 solder joints to be tested.

As far as PCBA industry is concerned, BGA detection has attracted more and more attention. X-ray detection is an important tool to ensure the quality of invisible solder joints during PCBA assembly. This is because X-ray detection technology can penetrate the package and directly detect the quality of solder joints. Due to the increasingly miniaturized packaging of semiconductor product components, better X-ray detection equipment is needed to meet the needs of miniaturized detection of product components.