The function of SMT Stencils
Simply say the sole purpose of an SMT stencil is to transfer solder paste to a bare PCB.
If you have visited a PCBA plant, most of SMT stencils are use stainless steel material.
Due to ensure high reliability for fine pitch and BGA components.
So SMT stencils are very important aid tool for PCBA.
How to make an SMT stencil?
If you have know the PCBA procedure, you may find the stencil is not all use PCBA board.
Most of them will be used before SMD procedure.
The SMT stencil is laser cut creating an opening for every surface mount device on the board.
By the way the laser cut is the main procedure for SMT stencil.
The detail procedure of SMT stencil we will introduce in furture posts, please follow our update.
The use method of SMT stencil
The first step is aligning the SMT stencil on top of the PCB board.
Then the operator must ensure solder paste is applied over the openings.
If making a single pass, most PCBA plants will choose a metal squeegee blade.
Most of the SMT stencil search on google is showing this step.
Then the SMT stencil should be separated from the PCB board.
So the solder paste will remain, ready for placement of the SMD procedure.
In one word, SMT stencil is used before SMD procedure.