One. Frame

According to the frame of the corresponding specification profile of the printing machine used by the customer, the common commonly used frame has the following types:

29X29inch 23X23inch 650X550mm

two. Stretch net

Firstly, the surface of the steel sheet is roughened with fine sandpaper and the edge of the steel sheet is polished, and then the net is stretched according to customer requirements.

Three. Steel sheet

In order to ensure sufficient tension and good flatness of the steel mesh, the steel sheet should be kept at a distance of 25mm from the inner side of the outer frame. For the specific steel sheet size, see Appendix II, “Aluminum Frame Specification Profile and Steel Sheet Cutting Size Correspondence Table”. It is recommended to select the corresponding steel sheet thickness according to different components, mainly based on the minimum opening and the minimum spacing. The key points are taken into account. See the table below or calculate according to the formula:

If the pad size is L>5W, the thickness of the steel sheet is calculated as the width to thickness ratio.

T<W/1.5

If the pad is square or circular, the thickness of the steel sheet is calculated by area ratio.

T<(L×W)/1.32X(L+W)

 Opening method

Note: The following opening methods only include some common typical parts. If you encounter a type of pad that is not mentioned in the following specifications, you can refer to the opening design with similar shape of the component pad.

A. Tinning mesh opening method:

The tin mesh opening method is suitable for most products to achieve the best solder paste release effect. If there are special requirements, it should be made according to requirements.

1. CHIP material components

The package is a rounded corner of the 0201 component with a 10% extension and a rounded R=0.03mm. The clearance guarantee must not be less than 9 MIL greater than 11 MIL.

The package is 0402 component opening as shown below (when the gap is less than 0.4mm, it needs to be moved to 0.4mm; when the gap is larger than 0.4mm, it needs to be expanded to 0.4mm):