PCB SMT Processing Factory Stencil Production And Acceptance Requirements

SMT small batch patch processing factory stencil production and acceptance requirements!

Steel mesh was originally made of wire mesh, so it was called stencil at that time. At first it was nylon (polyester) mesh, and later due to durability, barbed wire mesh, copper wire mesh appeared, and finally stainless steel mesh. But no matter what material the screen is made of, it has the disadvantages of poor molding and low precision. With the development of SMT, the small batch processing of smt patches has increased the requirements for stencils, and stencils have been produced accordingly. Affected by the cost of materials and the difficulty of production, the original steel mesh was made of iron/copper plates, but also because it was easy to rust, stainless steel mesh replaced them, which is the current steel mesh.

There are many raw materials and processing equipment in the SMT small-batch patch processing plant, and the steel mesh is one of the indispensable ones. The stencil of the SMT small-batch patch processing factory is actually a special mold for SMT patch processing . Its main function is to help the deposition of solder paste, and the purpose is to transfer an accurate amount of solder paste to the exact position on the PCBA substrate. Stencils play an important role in patch processing, and the quality of stencils even directly affects the quality of the entire SMT process.

SMT small batch patch processing factory's stencil production and standard acceptance requirements.

1. Production requirements:

(1) The board feeding direction and placement machine should be unified. (2) Mark the product model, thickness, production date, etc. (3) The size of the frame is determined according to the structure of the printing machine and the specifications of the product. (4) According to the relevant documents and materials of the SMT small batch patch processing factory, the supplier is required to make steel mesh. (5) The opening method and the size of the opening should be determined according to the type of each component. (6) Thickness (scraping glue is generally 0.18MM-0.2MMM, tin scraping 0.1MM-0.15MM).

2. Acceptance requirements:

(1) Whether the tension is good. (2) Whether the label is complete. (3) Whether the flatness is level. (4) Whether the frame size is correct. (5) Whether the thickness meets the product requirements. (6) Whether the opening mode and size meet the requirements. (7) Whether the opening position and quantity are consistent with the document.

The quality of the stencil in the SMT small-batch chip processing factory will directly determine whether the tin on the pad is uniform and full. The welding reliability of the products will have a great impact on the whole processing, so the steel mesh must be made strictly according to the demand to ensure the quality of each step in order to do a good job in the quality of the overall SMT chip processing.