Wednesday, October 23, 2013

SMT Stencils of Printed Circuit Board

SMT stencil is an important tool during the PCB assembly. If you are producing a printed circuit board with SMD/SMT components, using a stencil can allow you to apply an even and accurately placed coat of solder paste to the pads. This is often quicker and easier than doing it manually, especially if you working with more than one copy of the same board. A consistent and accurate coat of paste will reduce the number of solder bridges and decrease board cleanup time.

The sole purpose of an SMT stencil is to transfer solder paste to a bare circuit board. A stainless steel foil is laser cut creating an opening for every surface mount device on the board. Once the stencil is properly aligned on top of the board, solder paste is applied over the openings. When the stainless steel foil is separated from the board, solder paste will remain, ready for placement of the SMD. This process, as opposed to hand soldering methods, ensures consistency and saves time.

Stainless steel foil thickness and aperture opening size control the volume of paste deposited on the board. Too much solder paste causes solder balling, bridging, and tomb-stoning. A lack of solder paste creates insufficient solder joints. All of which compromise the electrical functionality of the board.

At Wonderful PCB Limited, we use Laser Technology to manufacture SMT Solder paste stencil, high tolerance aperture openings with superior registration for its solder paste stencils. With its 4 mil beam diameter, our Laser is capable of cutting small aperture openings to meet your size requirements. When you need to make the stencil, please kindly send us the file for production and advise us the size and thickness of the stencil, with or without frame. Normally it takes 24-48 hours to make the stencil. Here is the stencil we produced for you reference.

For more detailed information, please contact Mr. Stephen Zeng at email: . Thanks a lot!

No comments:

Post a Comment