A PCB Stencil is a sheet of stainless steel with openings used to place solder paste on a PCB board for surface mount component placement. Automotive PCB stencils can be classified based on their aperture type and mounting style:

Laser-cut Stencils: The openings / apertures on the PCB Stencil are created on a stainless steel sheet using a laser beam. This stencil provides a high degree of precision.

Chemical-etch Stencils: The openings on the PCB Stencil are etched into metal using acid. Such stencil offers high manufacturing speed at low cost but doesn’t protect the environment against harmful chemicals.

Framed / Framework PCB Stencils: These PCB Stencils come with a frame around the Stencil. A mesh border is used for the frame, which keeps the stencil sheet tight for the desired accuracy. Framed PCB Stencils offer consistent repeatability, exceptional print quality, and are used for high volume PCB production.

Frameless/ Reusable PCB Stencils: Such stencils don’t have a fixed frame. They can be adjusted into different frames and can be removed any time. They are less expensive than stencils with frames, can be used with hand soldering processes and also reduce storage

Prototype or Photo Stencils: These stencils are based on a specific design (custom made) prepared using CAD or Gerber file. These are used for manual printing and to exercise concepts.

Hybrid PCB Stencils: Hybrid stencil is a combination of the chemically etched and laser-cut stencil.