Incoming material inspection is the primary condition for ensuring the quality of pcb assembly。Because the quality of the components,PCB ,PCB assembled material is difficult or impossible to solve in the later process. The incoming material inspection items are as follows：
Incoming material | Inspection items | General requirements | Detection method |
components | Solderability | 235℃±5℃，2s or 0.2s or 230℃±5℃，3s±0.5s，Weld end 90% Dipped tin (lead-free250~255℃） | Wetting method and impregnation test |
Solderability | Reflow soldering：235℃±5℃，10~15s | Immersion test | |
Lead coplanarity | Optical plane and placement machine coplanarity inspection | ||
performance | Sampling, instrument inspection | ||
PCB | Size and appearance | Eye inspection | |
Warpage | Plane measurement | ||
Solderability | Rotary dipping, etc. | ||
Solder mask adhesion | Thermal stress test | ||
Process material | Solder paste | Percentage of metal | Heated weighing method |
Solder ball size | Measuring microscope | ||
Metal powder oxygen content | |||
Viscosity, processability | Rotary viscometer, printing, dispensing | ||
Binder | Bond strength | Pull force, torque meter | |
Craftability | Printing, dripping test | ||
Rod solder | Impurity content | Spectral analysis | |
Flux | active | Bronze mirror, welding | |
density | Densitometer | ||
No wash or washability | Eye inspection | ||
detergent | Cleaning ability | ||
Harmful to people and the environment or not | Chemical composition analysis | ||
