Flexible circuit board printed with protective film and production process thereof

Abstract

The invention discloses a flexible circuit board printed with a protective film and a production process. The production process comprises the following steps of sequentially printing an upper layer circuit, an upper layer insulating UV, an upper layer jumper wire and an upper layer waterproof adhesive on an upper layer PET to form an upper wire combination; sequentially printing a lower-layer circuit, a lower-layer insulating UV lower-layer jumper wire and a lower-layer waterproof adhesive on the lower-layer PET in sequence to form an offline combination; printing a layer of ink on the surface of the output end corresponding to the lower-layer circuit and drying the ink in a baking manner, thereby forming a layer of covered ink protective film on the surface of the output end of the lower-layer circuit; and directly laminating and combining the upper line combination, the middle PET layer and the lower line combination. By adopting the process of printing the baking type covering ink on the output end, the flexible circuit board has the advantages of higher production efficiency and lower production cost, and the printed ink protective film does not form a step between the middle-layer PET and the offline combination, so a problem that the electrical property of the flexible circuit board is influenced by circuit board oxidation, water inflow and the like caused by poor sealing is effectively avoided.

Description

technical field [0001] The invention relates to the technical field of flexible circuit boards, in particular to a flexible circuit board with a printed protective film and a production process thereof. Background technique [0002] Flexible circuit boards are mainly used in the fields of home appliance keys, computer keys and various key function equipment. It realizes electrical functions by printing conductive silver paste, insulating UV, carbon, etc. on PET. [0003] Such as figure 1 As shown, the conventional flexible circuit board is mainly composed of upper layer PET1, upper layer line 2, upper layer insulation UV3, upper layer jumper wire 4, upper layer waterproof glue 5, middle layer PET6, lower layer waterproof glue 7, lower layer jumper wire 8, lower layer insulation UV9, lower layer circuit 10. It is composed of 11 parts including lower layer PET11. Among them, upper layer PET1, upper layer line 2, upper layer insulation UV3, upper layer jumper wire 4, upper la...

AI Technical Summary

Problems solved by technology

[0004] For the flexible circuit board of the above-mentioned process, since the output end needs to be protected with a film after the assembly of the off-line is completed, steps are usually generated at the overlap between the protective film on the output end and the middle layer PET6, resulting in poor sealing between the middle layer PET6 and the off-line and resulting in circuit failure. Oxidation, water ingress, etc. affect the electrical properties of the flexible circuit board, and the process of pasting the protective film is relatively complicated, which reduces the production efficiency

Images