The Rigid Flexible Circuit Board has the stability of hard PCB and the soft Flexible PCB can be assembled in stereo, the prospect of development is very considerable.However, the process of making rigid flexible pcb is more complicated, which is more difficult to control in some key technical difficulties.The following KingSong circuit will be presented as a simple introduction to the structure of the six-layer Rigid-flex PCB.
1. This image showing the basic manufacturing process of rigid flexible pcb:
2.6 layer rigid flexible pcb stack up:
3. Difficulties in the production of Rigid Flexible Circuit Board:
(1) soft flexible board part:
Hard board PCB production equipment makes soft board, because flexible board material is soft, thin, soft plate over all horizontal line needs to use traction board to carry, avoid card board scrapping.
Pressure the PI cover film.Pay attention to the local PI cover film and the fast pressure parameter.Pressure must reach 2.45mpa in fast pressure, press it flat and compacted, no bubble cavity and other problems.
(2) hard rigid board parts:
Hard board Core Windows and PP.The hard board adopts the deep milling and open window, PP shall adopt no-flow PP, no-flow PP can prevent overloading of overspill.
For soft and hard combined plate pressure and shrinkage control.Due to the poor stability of the soft plate materials, it is important to finish the production of the soft board and the PI cover film, and make the hard board parts according to the coefficient of shrinkage.