Impact of pcb factory quick turn pcb production equipment on reflow soldering quality

It has very close relationship between Pcb factory quick turn pcb production reflow quality and pcb manufacturing processing equipment. The main factors affecting reflow soldering quality are as follows.

The quality of reflow soldering has a very close relationship with SMT processing equipment. The main factors affecting the quality of reflow soldering are as follows.

1. Printing equipment. The printing accuracy and repeatability of the SMT processing printing machine will play a certain role in the pcb factory quick turn pcb printing results, which will eventually affect the reflow quality; the template quality will also affect the SMT printing results, ultimately affecting the soldering quality. The thickness of the stencil and the size of the opening determine the amount of solder paste printed. Too much solder paste will cause bridging connection. Too little solder will result in insufficient solder or virtual soldering. The shape of the opening of the template and the smoothness of the opening will also affect the printing quality. The opening of the template must be downward, otherwise there will be residual solder paste in the horn chamfer once release the mold

2. Reflow soldering equipment. The temperature control accuracy of the pcb factory quick turn pcb reflow oven should reach ±0.1°C-0.2°C; the lateral temperature difference of the reflow oven conveyor belt should be below 5°C, otherwise it is difficult to guarantee the welding quality; the width of the reflow oven conveyor belt should meet the maximum PCB size requirement; The longer the length of the heating zone in the furnace and the greater the number of heating zones, the easier it is to adjust the temperature profile. Small and medium-sized batch production chooses 4-5 temperature zones, and the heating zone length is about 1.8m, which can meet the requirements. The upper and lower heaters should be independently temperature controlled to facilitate adjustment and control of the temperature profile; the maximum heating temperature of the reflow oven is generally 300 ° C ~ 350 ° C, considering the lead-free solder or metal substrate, should choose 350 ° C or more; the belt should be stable, the belt vibration will cause welding defects such as displacement, tombstoning, and cold welding.

For pcb manufacturers, good production equipment is not only a reflow soldering aspect, but also a basic responsibility embodiment for design and development of customer.