2 Layers Rigid-flex PCB Material

Rigid-flex PCB usually consists of flexible layers and rigid parts. The flexible layer is usually composed of the following materials:

Flexible polyimide core;

conductive copper layer;

Adhesive

The conductive copper layer is sandwiched on both sides with a flexible polyimide adhesive. The polyimide layer and the adhesive layer are generally considered as one unit (called the cover layer) which can be laminated to the copper layer with heat and pressure. Multiple flex layers can be used in any given design.

The rigid part is added to the flexible layer by a rigid layer of standard PCB material:

Fiberglass prepregs are infused with resins, which flow and bond when heated;

Non-conductive fiberglass base (usually FR-4);

Traditional green solder mask;

Our simple rigid-flex pcb manufacturing process

Rigid-flex boards are flexible circuit boards and rigid circuit boards, which are combined according to relevant process requirements after lamination and other processes to form a circuit board with FPC characteristics and PCB characteristics. After manufacturedthe FPC flexible board, going through those processes to complete the production of the Rigid-flex board. Please see bellow manufacturing process.

Rigid-flex board prototype

Due to the complexity of the production process of the rigid-flex board, some of the key technical difficulties are difficult to control, which are mainly reflected in the following two points:

1.Flexible board part:

Rigid board PCB production equipment produces soft boards. Because the soft board material is soft and thin, the soft board must be passed by a traction board to avoid scrapping the board when it passes through all horizontal lines.

Lamination of PI cover film. Note that the PI cover film should be applied locally, and the fast pressure parameters should be noted. The pressure should reach 2.45MPa during fast pressing, and it should be flat and compacted during fast pressing, and there should be no problems such as air bubbles and cavities.

2.Rigid board part:

Window opening and PP of rigid board Core. The hard board adopts controlled depth milling and window opening, and the PP should use NO-FLOW PP, which can prevent excessive glue overflow during pressing.

Rigid-flex board compression expansion and contraction control. Due to the poor expansion and contraction stability of the soft board material, it is necessary to give priority to the production of the soft board and the laminated PI cover film, and make the hard board part according to its expansion and contraction coefficient.

It is precisely because the production of rigid-flex boards is more complicated than that of other printed short-circuit boards, and the yield rate of finished products is lower. Therefore, proofing verification is required before mass application and mass production of rigid-flex boards.