Stainless Steel Stencil for Lighting PCBA
Stencils, or SMT Stencil, is a special SMT mold.Its main function is to help the deposition of solder paste.The aim is to transfer an exact amount of solder paste to an exact position on an empty PCB.
The development of SMT process, SMT stencil is also used in the adhesive process.SMT stencil is used for the half-liquid and half-solid state of solder paste printing on PCB board, circuit board except power board most use SMT technology, there are many surface paste bonding pad on the PCB, namely without hole welding way, and the stencil hole is corresponding to the pad on PCB, When manual brush tin, use horizontal hard brush to brush the semi-liquid and semi-solid tin paste through the holes in the stencil to PCB board, and then paste the components onto PCB by pasting machine, and then re-reflow to forming.
Stencil was originally made of silk screen net, so it was called "mask".First came nylon (polyester) masks, Later, due to the durability, there are barbed wire, copper wire mask, and finally stainless steel wire mask.But no matter what material silk screen, all have molding bad, precision not high defect.
With the development of SMT, the requirements for the mask are increased, and the steel stencil is produced accordingly. Affected by the cost of materials and the ease of fabrication, the original steel stencil was made of iron/copper plates, but it was also easy to rust, so the stainless steel stencil replaced them, which is now known as SMT Stencil.
What kind of PCB board should be engraved with laser stencil
Generally, it is PCBA that needs to engrave the steel stencil. Stencil function is mainly for leakage printing, which is used to print the solder paste. The solder is paste shaped, and the solder paste is printed on the solder pad. Then, the components are put on PCB and put into the stove, through the high temperature solder paste melting, so that the components can be welded.