Opening method of reflow soldering stencil for bottom double-row pin devices

Abstract

The invention discloses a hole opening method for reflow soldering steel meshes of bottom double row pin devices, and belongs to the field of electronic device manufacturing. The method includes obtaining the size of a grounding bonding pad of a device and the sizes of two rows of grounding pin bonding pads; obtaining the size of the grounding bonding pad on a printed circuit board and the sizes of the two rows of the grounding pin bonding pads; calculating the proportion of the bonding pad size on the device and the proportion of the bonding pad size on the printed circuit board; determiningsolder paste amount according to the proportions; making a reflow soldering steel mesh according to bonding pad patterns on the printed circuit board, wherein the hole opening positions and sizes on the reflow soldering steel mesh can be determined according to corresponding parts on the printed circuit board; and determining whether opening holes on the reflow soldering steel mesh is externally or internally tangent through tests. Thus, the problem of high fraction defective of the device when existing reflow soldering steel meshes are utilized to perform reflow soldering can be solved; and effects of enhancing the success rates during the welding of the device, reducing scrap costs and increasing repair rates can be achieved.

Description

technical field [0001] Embodiments of the present invention relate to the field of electronic device manufacturing, and in particular to a method for opening holes in a steel mesh for reflow soldering of devices with double rows of pins at the bottom. Background technique [0002] Reflow soldering stencil opening is a technology widely used in SMT (Surface Mount Technology, Surface Mount Technology). [0003] At present, for devices with double rows of pins at the bottom, the reflow soldering stencil opening method is still used in the conventional opening method, but this method is prone to cause problems. One is that the solder paste is too thick, and it is easy to connect tin after mounting to cause soldering bridges. , tilting; the other is that the solder paste is too thin, it is easy to solder less and cause false welding, and the via hole of the pad will eat part of the tin, which is more likely to cause false welding after reflow soldering. In addition, since the pa...

AI Technical Summary

Problems solved by technology

[0003] At present, for devices with double rows of pins at the bottom, the reflow soldering stencil opening method is still used in the conventional opening method, but this method is prone to cause problems. One is that the solder paste is too thick, and it is easy to connect tin after mounting to cause soldering bridges. , tilt; the other is that the solder paste is too thin, it is easy to solder less soldering to cause virtual soldering, and the via hole of the pad will eat part of the tin, and it is more likely to have virtual soldering after reflow soldering

In addition, since the package has no external leads, poor soldering is not easily detected by visual inspection, and it is easy to cause defective products to flow out

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