Rigid-Flex Circuit Board Adhesive Opening Definition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for manufacturing rigid-flexible circuit boards face challenges in defining openings in the flexible regions without leaving residual adhesive, which affects the durability and softness of the circuit board.
Innovation Solution
The method involves using removable sheets with a plastic base and adhesive film pressed onto semi-cured adhesive sheets, allowing for the definition of openings without residue by embedding the removable sheets in the adhesive and forming a step that enables easy removal without damaging the conductive layers, and subsequently forming outer conductive layers and electromagnetic interference shielding layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adhesive sheets are used to bond rigid and flexible regions, then the circuit board achieves structural integrity, but residual adhesive remains after opening definition which compromises durability and softness
Solution Approach 1:
The adhesive sheet is segmented into adhesive regions and non-adhesive regions (with openings) to allow selective bonding. The openings are defined in the adhesive sheet before lamination, enabling the adhesive to be present only where needed while leaving flexible regions free of residual adhesive for enhanced softness and durability.
Solution Approach 2:
The openings are defined in the adhesive sheet before the lamination process. This preliminary action ensures that when the adhesive sheet is laminated onto the circuit board, the adhesive material is already positioned correctly with gaps at the flexible regions, preventing residual adhesive from compromising the flexible areas.
2Ease of operation
If openings are defined in adhesive sheets to expose flexible regions, then softness is improved, but adhesive residue may damage conductive layers
Solution Approach 1:
The adhesive sheet is divided into adhesive portions and non-adhesive portions (openings) to enable selective bonding. This segmentation ensures that adhesive residue is prevented from reaching the flexible regions and conductive layers, eliminating the harmful effect while maintaining the necessary flexibility.
Solution Approach 2:
The adhesive sheet acts as an intermediary element that controls adhesive distribution. By pre-defining openings in the adhesive sheet, it mediates between the need for structural bonding and the need to protect flexible regions and conductive layers from adhesive residue damage.
3Manufacturing precision
If removable sheets are embedded in adhesive sheets for opening definition, then manufacturing precision is improved, but process complexity increases
Solution Approach 1:
The openings are defined in the adhesive sheet before lamination, which is a preliminary action that simplifies the overall process. This approach achieves high manufacturing precision for opening definition without requiring complex removable sheet mechanisms, as the openings are directly formed in the adhesive material itself.
Solution Approach 2:
The unnecessary complexity of removable sheets is extracted from the process. Instead of using removable sheets to define openings, the invention directly defines openings in the adhesive sheet, taking out the intermediate step and simplifying the manufacturing process while maintaining precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures the removal of removable sheets without residue, maintaining the integrity of the conductive layers and preventing damage, thereby enhancing the durability and softness of the rigid-flexible circuit board.
Implementation Method 1
a rigid-flexible circuit board comprises a rigid board, a flexible board, and an adhesive sheet, in which the adhesive sheet is connected to the rigid board and the flexible board
Data Source
AI summary
A method for manufacturing rigid-flexible circuit board includes the step of providing an adhesive sheet defining at least one first opening, a copper foil, and a flexible board. The flexible board comprises a mounting region and a folding region. A removable sheet is pressed on a pressed surface of the adhesive sheet corresponding to each first opening. The copper foil, the adhesive sheet with the removable sheet, and the flexible board are pressed together in that sequence. The removable sheet corresponds to the folding region, and is embedded in the adhesive sheet. The copper foil contacts with the pressed surface and the removable sheet. An interspace is formed between the removable sheet and the flexible board. An outer conductive layer is formed on the copper foil. A removing region of the outer conductive layer corresponding to the folding region and the removable sheet is removed.