Soldering Offset Prevention Method for Surface Mount Devices

Abstract

A welding skewing-proof method for a surface mounting device comprises the following steps: (1) making a steel mesh and utilizing surface mount technology (SMT) printing equipment to cover welding paste on a printed circuit board (PCB) surface, thereby enabling a steel mesh opening which is served as the center of the welding paste printing to overlap the actual center point of surface installation device paster, (2) pasting the paster, using the SMT paster equipment to place the to-be-installed surface mounting device on a corresponding position of a PCB plate so as to enable a leading foot of the to-be-welded surface mounting device to cover the whole welding paste, (3) conducting reflow soldering, utilizing reflow furnace equipment, and by means of concrete curve heating arrangement, enabling the welding paste to be converted and form eutectic soldered dots.

Description

technical field [0001] The invention relates to the field of semiconductor packaging, and more specifically, the invention relates to a method for preventing solder offset of surface mount devices. Background technique [0002] Surface Mounted Technology (SMT) is currently the most popular technology and process in the electronics assembly industry. [0003] In the surface mount process, solder paste printing is the first link in the entire process, and the printing quality will directly affect the pass-through rate of surface mount products. According to statistics, 60%-70% of welding defects are directly related to the printing quality, and among the various factors affecting the printing process, the design and production technology of the printing stencil plays a pivotal role. [0004] There are TO265 packaged devices in SMT welding, and its appearance is as follows figure 1 As shown, the number 10 represents the part of the surface mount device pin (pin) to be soldere...

AI Technical Summary

Problems solved by technology

[0005] TO265 packaged devices often generate a lot of heat when they work, so the grounding pad designed on the PCB board (Printed Circuit Board, also known as printed circuit board, printed circuit board) is often 1-2 times larger than the actual device , this solder pad is prone to produce tin beads during soldering, and the tension is high during reflow, which is easy to cause displacement; that is, although the conventional stencil opening design meets the requirements for the amount of solder paste, there is a phenomenon of chip offset after reflow soldering

The common pad opening is 1:1 opening, but the results after soldering show that deviation is very easy to occur

This undoubtedly brings unnecessary efficiency loss to production. In order to ensure reliability and reduce defect rate at the same time, it is an inevitable choice to find a more suitable opening method.

Images