1. The guide hole is designed on the solder pad. When reflow oven is conducted, the solder will melt and leak through the hole to the metallization hole or bottom layer, causing defects such as too little solder joint, soldering, stele and thermal stress, etc.
2. When the hole is on the pad, the solder joint will be significantly less tin.
3. Conducting hole is set on the solder pad, causing welding defects.
4. The hole is designed on the solder pad of QFN components, which leads to the loss of solder and the reduction of heat dissipation grounding effect. The hole is set on the heat dissipation grounding pad of components, which leads to the loss of solder and the reduction of heat dissipation grounding effect.
5. The hole design has hidden defects in the heel part of SOP packaging components, which is not easy to be found and has potential reliability problems.
6. The hole is on the solder pad, resulting in false soldering.
