How are Kingsheng PCB stencils formed? - China PCBA Supplier

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There are various technologies for forming PCB stencils
Laser
Electroformed
Chemically etched plastic
Hybrid – a combination of chemically etched and laser-cut.

In chemically etched PCB stencils, the stencil is etched from both sides using two positive images. The PCB etching process leaves aperture walls that taper to an hour-glass shape in the centre of the aperture. In laser-cut PCB stencils, a stainless steel foil is cut by laser, creating an opening for each component that will be included in the final PCB. For both processes, aperture walls are electro-polished to ensure a smooth finish. Following the PCB cutting process, the stencil is aligned over the board. The solder paste is deposited over the apertures. After the PCB solder is laid, the foil is removed.

Ensuring the correct amount of solder paste

It is vital to ensure that the amount of solder being laid down meets PCB design specifications. If not enough PCB solder is used, there is a risk of inadequate solder joints. In contrast, much solder can result in balling, bridging and tomb-stoning. Both options can disrupt the electrical functionality.