NL 
EN 
ES 
FR 
AR 
PT 
RU 
DE 
IT 
TR 
PL 
CS 
RO 
SK 
ZH 
JA 
KO 
ID 
The core of X-ray inspection technology lies in utilizing the penetrating properties of X-rays to visualize the internal structure of objects. When X-rays pass through materials of different densities, they are absorbed to varying degrees due to these density differences, thereby forming corresponding internal images. Specifically, denser metallic materials, such as solder joints, exhibit strong absorption of X-rays, resulting in distinct contour images. In contrast, materials with lower density, such as PCB substrates or voids within solder joints, absorb fewer X-rays, leading to varying shades of gray in the images. After the inspection equipment accurately captures these differences, it can construct precise images of the object’s internal structure, providing intuitive evidence for subsequent defect detection and analysis.
First, we want to discuss the application of X-ray inspection technology in SMT industry. In SMT assembly, the solder balls of packaging types such as BGA (ball grid array) and CSP (chip-scale packaging) are located at the bottom of the pins, and the solder joints are covered by the packaging body, making it difficult for traditional optical inspection (AOI) to effectively check their soldering quality. The first application is soldering void inspection: during the reflow soldering process, if the gas in the solder paste cannot be completely removed, it will form voids in the solder joints. The presence of these voids weakens the structural strength of the solder joints, reduces their electrical conductivity, and may even cause premature failure of electronic components; The second application is soldering bridging inspection: during the soldering process, excessive solder or inaccurate solder pad placement can cause bridging between solder joints. Bridging can disrupt the normal electrical performance of the circuit and cause faults such as short circuits. X-ray inspection can clearly show the distribution of solder between solder joints, accurately detect whether there is excess solder bridging, ensure that the electrical performance of the circuit meets design requirements, and promptly eliminate this safety hazard; The third application is open circuit and cold solder joint detection: in some cases, due to incomplete melting of solder or improper welding operations, cold solder joints or open circuits may occur. These welding issues can severely impair the electrical conductivity of circuits, causing electronic devices to malfunction. X-ray inspection enables precise detection of the density and shape of solder joints, effectively identifying defects such as cold solder joints and open circuits. This provides accurate evidence for timely repairs, ensuring the performance and quality of electronic products.
Second, we want to discuss some unique advantages of X-ray inspection technology. The first advantage is lossless inspection characteristics: X-ray inspection is a non-destructive testing method that does not cause any physical damage to PCBs or welded parts. This feature allows manufacturers to monitor the quality of welds in real time during the production process, identify and resolve potential issues promptly, without worrying about adversely affecting the performance of the final product. Compared to some destructive testing methods, X-ray inspection can ensure product quality while reducing testing costs and improving production efficiency; The second advantage is high-definition imaging and reliability: X-ray inspection technology can produce high-resolution images of small details such as solder joints, ensuring comprehensive and detailed inspection of welding quality. Even internal defects that are difficult to detect using traditional inspection methods can be clearly revealed through X-ray images, providing inspectors with accurate and reliable inspection results. This highly reliable inspection method helps improve the overall quality of products and enhance market competitiveness; The third advantage is the ability against complex structure of packaging: with the development of the electronics industry, PCBs with high-density, complex packaging structures, such as BGA, CSP, and PoP, are becoming increasingly common. The soldering quality of these packaging forms is critical to the performance of the entire circuit board, but traditional inspection methods often struggle to cope. X-ray inspection technology, with its powerful penetration capabilities and precise imaging effects, can easily meet the inspection requirements of these complex packaging structures, promptly identifying and repairing potential soldering defects to ensure the high-performance operation of the circuit board;
The fourth advantage is the support of batch testing and automated production: X-ray inspection technology can be used not only for individual PCB inspection, but also for online inspection in mass production processes. Combined with advanced automation equipment, X-ray inspection enables fast and efficient quality control in large-scale production processes. This not only improves production efficiency, but also ensures that the soldering quality of each PCB meets strict standards, providing a strong guarantee for the stable production of electronic products.
Third, we want to discuss some common problems faced during the X-ray inspection procedure, as well as their corresponding solutions. The first problem is soldering void issue: Voids inside solder joints are one of the most common defects in SMT assembly, particularly during BGA soldering. Excessively large voids can weaken the mechanical strength and electrical conductivity of solder joints, affecting the stable operation of electronic components. To solve such issue, X-ray inspection technology can precisely measure the size, shape, and distribution of voids, ensuring that the void rate is controlled within reasonable limits; The second problem is solder ball deformation or depression issues: during the BGA soldering process, deformation or indentation of solder balls can seriously affect the soldering results. Abnormal solder ball shapes can lead to poor contact at solder joints, reduced electrical conductivity, and even false soldering. To solve such issue, X-ray inspection can clearly detect abnormal solder ball shapes and provide early warning of soldering quality issues;
The third problem is the misalignment chip component issue: during the SMT assembly process, misalignment of workpieces may occur due to machine malfunctions, operator errors, or material quality issues. Workpiece misalignment can affect the installation accuracy and electrical performance of electronic components, leading to product malfunctions. To solve such issue, X-ray inspection can check the accurate position of workpieces, promptly detect and correct misalignment issues.
To conclude, in modern electronics manufacturing, electronic components and circuit boards are becoming increasingly smaller and more complex, placing higher demands on inspection technology for SMT assembly. X-ray inspection technology, with its efficient, non-destructive, and precise inspection advantages, has become an effective means of addressing soldering defects that traditional optical inspection methods cannot adequately address. It not only ensures the reliability of high-density circuit board soldering but also significantly enhances quality control throughout the entire production process.