X-Ray
X-ray inspection is a nondestructive testing technology that uses low-energy X-rays to penetrate circuit boards and generate images of their internal structures, allowing for rapid analysis of the soldering quality of electronic components and semiconductor packaging products without damaging the sample.
Why X-Ray Inspection Is Necessary
With the development of SMT and PCBA technology, component packages are becoming smaller and more concentrated. Now a lot of soldering it buried under components like:
BGA (Ball Grid Array)
QFN (Quad Flat No-Lead)
CSP and other miniaturized packages
Multilayer boards / HDI (High-Density Interconnect)
For this matter, traditional inspection methods such as AOI or visual inspection cannot reach, observe or check these solder joints hiding in the dark. X-Ray inspection, on the other hand, is able to go through the components and solder joints so that inspectors can “look inside” the assembly to find hidden defects with perfect accuracy.
What Can X-Ray Inspection Detect?
X-ray examination can penetrate the inside of components and solder joints, which makes it the best method to detect buried solder joint defects. The following is a list of common soldering defects and internal structural defects that can be clearly identified by X-ray imaging:
1. Solder Joint Defect Inspection
X ray inspection can detect soldering joint problems that traditional inspection cannot find such as cold solder joints, voids, misregistered solder joints, bridging, ball short circuits, insufficient or incomplete solder wetting, among other things.When solder joints internal structure is revealed, baking line engineers can quickly evaluate soldering quality and instantly confirm robust and reliable connections.
2.BGA / QFN Bottom-Side Solder Joint Inspection
For BGA, QFN, and CSP packages which are bottom-terminated, X-raying the solder ball is the only way to view the shape, size, coining and contact between balls and pads. It can detect critical defects including solder ball detachment, open circuits and misalignment, which is key for ensuring high density packaging soldering reliability.
3.Internal Component Defect Analysis
Solder joints can be inspected with X-ray, as can the internal structures of components where defects such as internal breaks in capacitors and inductors and damage inside IC packages or wire bonding. These internal faults are typically undetectable to the naked eye, while x-ray images serve as direct evidence in failure analysis.
4. PCB Internal Structure Inspection
In the case of multilayer PCBs, X-ray inspection can assess interlayer registration, the integrity of through-hole, blind via, and buried via walls, and the thickness of plating layers. With the internal structure of the PCB to be viewed, engineers can successfully detect potential manufacturing defects and enhance reliability.
Advantages of X-ray Inspection
1. Non-destructive testing
The internal structure of the circuit board can be viewed and analyzed without cutting the board.
2. High precision
Micron-level solder joint defects can be detected.
3. Suitable for high-density packaging
X-ray can inspect solder joints in packages such as BGA, QFN, and CSP.
4. Improved quality reliability
Pre-shipment inspection prevents problematic or potentially problematic boards from reaching customers.
Conclusion
X-ray testing is now a requisite for quality control in the production of PCBA in the modern world. It can penetrate internal structure that traditional inspection can not penetrate, accurately detect solder joint defect, packaging defect and the hidden defects in multi-layer PCB. With electronic products evolving toward smaller size, higher density, and better reliability, the importance of X-ray technology in quality control will only increase.
Providing high quality PCB/PCBA manufacturing and testing service, LingKey is equipped with leading X-Ray inspection machines and experienced engineering team to assist customers to identify risks at an early stage and to improve their production yield and to make sure that each and every circuit board can achieve the highest level of reliability. LingKey is always your best choice for more accurate, more professional quality assurance of your electronic products.
