Improving the solderability of BGA (Ball Grid Array) packages is always a big challenge for the SMT (Surface Mount Technology) process. Fine pitch BGAs (with a ball pitch less than 0.8mm) are particularly difficult to solder onto the PCB. Additionally, inspecting the soldering result is challenging because the solder joints are hidden under the BGA body, and sometimes even 2D X-Ray inspection is insufficient. (5Dx or angle rotation X-Ray might be able to inspect BGA soldering quality, but these methods are expensive.)
Experience tells us that most BGA solderability failures are caused by the HIP (Head-In-Pillow) or call HoP (Head-on-Pillow) soldering defect, and over 90% of HIP defects occur at the four corners of the BGA package. This is due to the longer diagonal distance and the greater impact from board warpage and BGA deformation. Many senior SMT engineers have conducted experiments and proven that increasing the solder paste volume on the pads under the BGA can reduce the risk of HIP defects.
Do you know how vendor ensure that their products are not damaged during shipping due to handling by transporters or delivery personnel? Reputable vendors put effort into designing and selecting suitable packaging materials for shipping to ensure the quality of their products. This article will introduce how vendor test whether their cardboard packaging meets general shipping requirements.
