Thickness of Stencils :
In PCB stencil design, the thickness of stencils is a key factor that would decide the amount of solder paste to be deposited on the board, extra solder deposition would cause solder bridging, while less solder deposition makes the solder joints weak. Normally, the thickness of stencils is from 4 thou to 8 thou.
Aperture Size :
The size of stencil openings needs to be designed smaller than the PCB pad size which can avoid problems such as bridging and solder beads, or the solder paste may stick to the aperture walls when the stencils are removed. Therefore, the inner area of the aperture wall should be designed to be two-thirds smaller than the area of the PCB pad to avoid such problems.
Stencil Material :
The material used to make stencils is another factor to consider during PCB stencil design, which affects the ability to release the solder paste from the opening to the PCB pad. The most used material is stainless steel, while for some PCB designs with fine-pitch devices, we need to use other materials such as nickel which is 50% more expensive than stainless steel.
Stencil Alignment :
Good stencil alignment is critical to getting an accurate solder paste print. To achieve the perfect printing effect, we need to add the fiducial marks to both the PCB and stencil. These fiducials ensure the proper alignment of the stencil and the printed circuit board.
Ultimately, producing PCB stencils necessitates advanced skills and expertise. Collaborating with a trusted PCB stencil manufacturer is recommended if you lack proficiency. Pcbciruit Technology specializes in PCBA services, providing PCB fabrication, SMT stencil creation, PCB assembly, testing, and shipping services. We have extensive experience in PCB contract manufacturing.
August 30, 2024 - BY Admin