Talking about the little-known soldering defects of PCB circuit boards

When the circuit board is soldered, defects often occur. The common ones are virtual soldering, solder accumulation, too much solder, too little solder, rosin soldering, overheating, cold soldering, and poor infiltration. So, in addition to what I just said, what are the other flaws? Let me explain it for you in detail below: 1. Asymmetry: The solder does not flow over the pad. Harm: insufficient strength. Reasons: 1) The solder has poor fluidity. 2) Insufficient flux or poor quality. 3) Insufficient heating. 2. Looseness: The wire or component lead can be moved. Hazard: Poor or non-conduction. Reasons: 1) The lead moves before the solder is solidified and causes a gap. 2) The lead is not processed well (poor or not wetted). 3. Sharpen the tip: the tip appears. Harm: Poor appearance, easy to cause bridging. Reasons: 1) Too little flux and too long heating time. 2) Improper evacuation angle of the soldering iron. 4. Bridge connection: adjacent wires are connected. Hazard: Electrical short circuit. Reasons: 1) Too much solder. 2) Improper evacuation angle of the soldering iron. 5. Pinholes: There are holes visible through visual inspection or low-power amplifiers. Hazard: Insufficient strength, easy to corrode solder joints. Reason: The gap between the lead and the pad hole is too large. 6. Air bubbles: there is a fire-breathing solder bulge at the root of the lead, and a cavity is hidden inside. Hazard: Temporary conduction, but it is easy to cause poor conduction for a long time. Reasons: 1) The gap between the lead and the pad hole is large. 2) Poor lead wetting. 3) The welding time of the double-sided board plugging the through hole is long, and the air in the hole expands. 7. The copper foil is lifted up: the copper foil is peeled from the printed board. Hazard: The printed board is damaged. Reason: The welding time is too long and the temperature is too high. 8. Peeling: The solder joints peel off from the copper foil (not the copper foil and the printed board peeling off). Hazard: cause an open circuit. Reason: Bad metal plating on the pad. The above is the little-known soldering defects of PCB circuit boards that I have talked about. Have you mastered all of them?