Asymmetric rigid-flex circuit board and its preparation method

Abstract

The invention discloses an asymmetric flex-rigid combined circuit board and a preparation method thereof. The preparation method comprises the steps of flexible plate production, rigid plate production, dielectric layer production, laminating and the like. According to the asymmetric flex-rigid combined circuit board prepared provided by the invention, the product yield can be effectively improved, and the product performance reliability can be enhanced; furthermore, the asymmetric flex-rigid combined circuit board is simple in flow and smart in design; in addition, the asymmetric flex-rigid combined circuit board can be prepared by commercial equipments and materials of the circuit board, the mass preparation can be carried out, and the integrity and appearance of the circuit can be improved greatly.

Description

technical field [0001] The invention relates to the technical field of printed circuit boards, in particular to an asymmetric rigid-flexible circuit board and a preparation method thereof. Background technique [0002] With the development of PCB (Printed Circuit Board, printed circuit board) in the direction of small size, light weight, three-dimensional installation and high connection reliability, rigid printed circuit boards and flexible printed circuit boards began to move towards rigid-flexible boards. Development, the rigid-flex board is one of the main growth points of the PCB industry in the future. The feature of ordinary rigid-flex boards is that the flexible area can be bent to achieve three-dimensional installation during subsequent assembly. [0003] The asymmetric double-sided rigid-flex circuit board is a rigid-flex circuit board with a simpler structure and lower cost evolved from the ordinary rigid-flex circuit board. The rigid-flexible board with this st...

AI Technical Summary

Problems solved by technology

[0010] 1. The above-mentioned process produces asymmetric structure double-sided rigid-flex board, and the pure flexible area circuit on the flexible layer cannot be produced or the yield rate is extremely low

[0011] 2. Poor product reliability

[0013] 1. In the pure flexible area, there are steps between the flexible layer and the rigid layer due to the hollowing out of the pure rubber adhesive sheet, resulting in poor exposure during the production of the flexible layer circuit, and defects such as open circuits, short circuits, and gaps after etching.

[0014] 2. The PI surface of the single-sided flexible board is relatively smooth, and the bonding force with the adhesive sheet is poor. The above-mentioned structure is easy to delaminate, and the reliability is poor.

[0015] 3. The adhesive sheet used between the flexible layer and the rigid layer is pure glue, which is thermosetting glue, which is easy to absorb water when placed in the air. After the pure glue absorbs water, the bonding force is poor and it is easy to delaminate, resulting in poor reliability.

Images