What Are The Requirements For PCBA Processing And Welding?

In PCBA processing, welding is a main connection method, a basic skill of PCBA processing, and one of the main methods of metal processing. Soldering-related issues are considered at every stage of the PCBA process. Below, Tecoo will introduce to you what are the requirements for PCBA plus welding:

◆ The height of the pins on the soldering surface of the plug-in components is 1.5-2.0mm. The SMD components should be flat on the board surface, the solder joints should be smooth without burrs and slightly arc-shaped, and the solder should exceed 2/3 of the height of the soldering end, but should not exceed the height of the soldering end. Less tin, spherical solder joints or solder covering patches are all bad;

◆ The height of solder joints: the height of solder climbing pins should not be less than 1mm for single panel, not less than 0.5mm for double panel and need to penetrate tin.

◆ Solder joint shape: It is conical and covers the entire pad.

◆ Solder joint surface: smooth and bright, no black spots, flux and other debris, no thorns, pits, pores, exposed copper and other defects.

◆ Solder joint strength: fully wetted with pads and pins, without false soldering and false soldering.

◆ Cross-section of solder joints: The cutting feet of the components should not be cut to the solder part as much as possible, and there is no cracking phenomenon on the contact surface between the pins and the solder. There are no spikes and barbs at the cross section.

◆ Needle seat welding: The needle seat needs to be inserted into the bottom board, and the position is correct and the direction is correct. After the needle seat is welded, the bottom floating height should not exceed 0.5mm, and the seat body should not be skewed beyond the silk screen frame. The rows of needle seats should also be kept neat, and no dislocation or unevenness is allowed.