BGA Poor Welding Detection and Re-welding Problems

If the general X-ray machine virtual welding problem can not be checked out, can you use red ink and section to find the problem? But if heating or reflow oven welding, PCBA processing after the test and passed, then do red ink and slice test will be useful? If the customer asks to take the good board to do it again, can we see that it is the process problem?

Q1: Generally, if the false welding of non-BGA parts can be seen by the naked eye, because the solder of the false welding will form an obvious welding defect, which can be easily identified under normal soldering condition.

From the description of the question, we can guess that the questioner should have encountered the abnormal quality of BGA or IC component welding. 3DX-Ray scanning imaging can be used to detect false welding in SMT SMT processing. This is also the main effective equipment and method for welding inspection of BGA/IC components, which is undoubtedly confirmed by the vast majority of PCBA manufacturers.

But if the ball itself is broken or the quality of the ball is abnormal, it may have to be analyzed using red ink and slice test, because this anomaly is not detected by X-ray.

Q2: If the problem of BGA is not confirmed, the solder paste is reflow oven welding again, which may cover up the real problem point. In addition, another problem is that the source of quality points will be destroyed, so it is not guaranteed that we can check out the real bad points.

BGA failure should first eliminate the quality problems of the tin ball itself, and the rest should be confirmed as problems of welding interface or temperature adjustment. Different links will produce different abnormal points. And a lot of bad BGA welding is not necessarily a process problem.
If we really want to analyze, it is suggested to take out a piece of defective products for all-round detection, verify with the quality anomalies of each link, to prove whether we really encounter this kind of defect, and then solve it accordingly.

SMT production line

Zhejiang NeoDen Technology Co., LTD., founded in 2010, is a professional manufacturer specialized in SMT pick and place machine, reflow oven, stencil printing machine, SMT production line and other SMT Products. Skilled and professional english support&service engineers, to ensure the prompt response within 8 hours, solution provides within 24 hours. The unique one among all of the Chinese manufacturers who registered and approved CE by TUV NORD.

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Post time: Sep-30-2021