Stencil printing can have two forms, one is the screen printing stencil, the other is hollow stencil printing.
Screen mask is formed on the screen mask pattern, paint through the screen printing to the substrate; hollow template is formed in the stencil on the hollow pattern, paint through the hollow graphics printing to the substrate. Obviously, the screen stencil due to mesh support, there can be no connection on top of the pattern, and hollow stencil must consider the hollow graphics connection problem.
Screen stencil printing is a traditional T industry printing technology for screen printing in micro-nano processing. It is nothing more than making the pattern on the stencil smaller and the mesh of the screen thinner. However, due to the mesh limit of the screen itself, the screen printing pattern is usually several tens of micrometers or more than several hundred micrometers. The pattern on the screen can be formed by the method of optical exposure of the photoresist. After the photoresist is developed, the screen is naturally formed. Screen printing has the unique advantage of making thick-film piezoelectric devices. Because the piezoelectric material is mainly leadzirconate titanate (PZT), the PZT material can neither be deposited by the above physical or chemical methods, nor can it be processed into a pattern by traditional etching methods. Using screen printing method, PZT can be made into a slurry and then painted on a screen mask. In this way, a thicker PZT film can be obtained. And can form the desired PZT pattern structure. This technique has been extensively used to make PZT-driven micro-actuators or microfluidic pumps and other micro-devices. The structure of such micro-device size is relatively large, screen printing resolution resolution can do exactly.
Hollow stencil printing is also a traditional industrial printing technology. Hollow stencil printing and stencil printing is different from the printed material directly through the hollow area deposition to the substrate. It can be applied by screen printing, or by thermal evaporation to the surface of the substrate through the hollow region. For example, the metal material is evaporated and deposited on the surface of the substrate to form a metal pattern.