A structure for improving the bad opening gap of FPC with air-gap

Abstract

The invention discloses a structure for improving the bad open circuit gap of FPC with Air-gap, which includes a flexible circuit board body, and the flexible circuit board body includes a first outer layer of copper, pure glue, an inner layer of copper, a PI layer and a second outer layer. A layer of copper, the upper end of the first outer layer of copper is provided with a trapezoidal groove, and the trapezoidal groove part forms an Air-gap area, the Air-gap area is filled with ink, and the first outer layer of copper on the outside of the ink Laminated with a dry film, the first outer layer of copper and the inner layer of copper are fixedly connected by pure glue, and the PI layer is correspondingly connected between the inner layer of copper and the second outer layer of copper. The invention makes the ink cover the Air-gap area, and the outer surface of the ink is covered with a dry film, which increases the adhesion of the dry film, effectively improves the open circuit and gap defect of the pit step position, and improves the line yield from 80%. to 95%, enhancing market competitiveness.

Description

technical field [0001] The invention relates to the technical field of flexible circuit boards, in particular to a structure for improving the bad open circuit gap of FPC with Air-gap. Background technique [0002] With the development of multi-layer high-density interconnected FPC, multi-dimensional bending has been widely used in electronic communications, e-readers, etc. in multi-layer FPC. In response to bending requirements, the Air-gap design in the single-layer area has become a common design in this type of FPC manufacturing, but the traditional design has a difference in height after the outer layer lamination process is completed. [0003] In addition, on the surface of the Air-Gap, there will be dry film pressure on the bottom corner of the copper. The appearance is air bubbles. The dry film cannot be tightly combined with the copper surface. The dry film will fall off after development, and open circuits and gaps will appear after etching. For this reason, we pr...

AI Technical Summary

Problems solved by technology

To meet the bending requirements, the Air-gap design in the single-layer area has become a common design in this type of FPC manufacturing, but the traditional design has a height difference phenomenon after the outer layer lamination process is completed.

[0003] In addition, on the surface of the Air-Gap, there will be dry film pressure on the bottom corner of the copper. The appearance is air bubbles. The dry film cannot be tightly combined with the copper surface. The dry film will fall off after development, and open circuits and gaps will appear after etching. situation, for this reason, we propose a structure to improve the bad opening gap of FPC with Air-gap to solve the above-mentioned problems

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