How to inspect BGA solder joints in SMT processing?

BGA inspection: how to inspect BGA solder joints in SMT processing?

Abstract: In the process of SMT patch processing, we often encounter BGA devices, which are also the core components of the entire PCBA. If a fully functioning PCBA is compared to a person, then the core of the command center or brain must be a BGA device. The quality of BGA soldering is directly related to whether the entire PCBA board can work normally, whether the BGA soldering can be accurately controlled during SMT patch processing, and whether the subsequent inspection can detect whether there are hidden dangers in the soldering problem, and can solve it. Take appropriate action.

The BGA soldering point is not like a J-shaped pin-packaged device, and it can be judged by the naked eye whether the soldering is good. The welding of BGA is that the solder joint is under the chip body, and the tight solder ball corresponds to the position of the PCB circuit board pad after the SMT welding is completed. Ordinary people look normal, and it is opaque, so it is difficult to judge whether the quality of the welding inside is good with the naked eye.

In the absence of testing equipment for BGA solder joint inspection, we can only see the outer ring of the chip to check whether the solder joints collapse in one direction. Then carefully inspect the place where the BGA faces the direct light, and each column is a row of solder balls so that it can be visualized through light. At this time, we can probably rule out the problem of continuous soldering. But to judge the quality of internal solder joints more clearly, such inspections are not enough. X-ray must be used.

X-ray is a kind of CT scanning equipment, we may have seen it in the hospital. Its advantage is that it can directly carry out a special inspection on the inside of the circuit board through X-ray without disassembling the device. It is the equipment often used by PCBA processing plants to inspect BGA soldering. Use an X-ray to scan the inside of the BGA to produce a tomographic image effect, and then layer the solder balls of the BGA to produce a tomographic image effect. According to the comparison between the original design data map and the parameter image set by the user, the X-sectional image can judge whether the welding is qualified when appropriate.

Its advantage is that it can not only detect the BGA option but also the solder joints of all packages on the PCB circuit board, which can be used for multiple purposes. But its shortcomings are also very obvious. First, the radiation dose is significant, and long-term use is not good for employees’ health. Two: The price is too high.

Generally speaking, the chip processing accuracy of electronic products is becoming more and more integrated. Most of the PCBA boards will use BGA components or QFN, etc. To better soldering quality, we should configure the corresponding detection equipment X-ray, Improve the quality pass-through rate.

The above content is the BGA soldering quality inspection method shared by sztech-smt for you. I hope it will be helpful to you. To learn more about SMT patch processing, welcome to visit www.sztech-smt.com

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