http://pastport.jp/user/C-alley/timeline/Factors%20of%20poor%20PCB%20surface%20quality%20in%20PCBA%20processing The support height (the space between the PCB and the ground clearance) is likewise getting smaller and smaller as the density and size of PCBA components increase. Additionally, the PCBA is affected by environmental factors. The impact is growing and inc ja-JP