LED chip printing steel mesh

Abstract

The invention relates to the field of semiconductors, and discloses an LED chip printing steel mesh which comprises a steel plate (1) and a plurality of bonding pad openings (2) formed in the steel plate (101), the shape of each bonding pad opening (2) is the same as that of each solder ball bonding pad (3) on an LED chip to be printed, and the LED chip printing steel mesh is characterized in that the area of each bonding pad opening (2) is larger than that of each solder ball bonding pad (3); and compared with the condition that the area of the bonding pad opening (2) is equal to the area of each solder ball bonding pad (3), the thickness of the printing steel mesh, namely the thickness of the bonding pad opening (2), is reduced, and the volume of the solder ball on each solder ball bonding pad (3) is kept unchanged after printing backflow. Compared with the prior art, the printing steel mesh is low in precision requirement during printing, demolding is easy, the solder paste tip pulling abnormal rate generated during printing is reduced, and the uniformity of high-density printing is improved.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a steel screen for printing LED chips. Background technique [0002] At present, high-density LED chips are densely arranged on the chip source, and the printing accuracy of the stencil is relatively high. In the prior art, the pad openings on the LED chip printing stencil are smaller or smaller than the pads on the LED chip to be printed. same. This requires high precision of the opening of the pad when making the stencil, otherwise the large offset of the stencil will easily cause a misalignment between the pad on the LED chip to be printed and the subsequent printing, resulting in uniform printing of high-density solder paste Poor performance, and due to the small size of the pad opening, it is easy to produce printing abnormalities such as solder paste sharpening when demoulding after printing solder paste. In addition, the thickness of the stencil, that is, the thickness of th...

AI Technical Summary

Problems solved by technology

This requires high precision of the opening of the pad when making the stencil, otherwise the large offset of the stencil will easily cause a misalignment between the pad on the LED chip to be printed and the subsequent printing, resulting in uniform printing of high-density solder paste Poor performance, and due to the small size of the pad opening, it is easy to produce printing abnormalities such as solder paste sharpening when demoulding after printing solder paste. In addition, the thickness of the stencil, that is, the thickness of the pad opening is thick, which will cause difficulty in demoulding

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