Rigid-Flex Circuit Board Flying-Tail Solder-Resist Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The traditional manufacturing method for rigid-flex circuit boards with a flying-tail structure often damages the solder-resist layer, leading to a low qualified rate due to its vulnerability under high temperatures and pressures.
Innovation Solution
The use of polyetherimide covering films attached to the solder-resist areas of adjacent end surfaces of second parallel planar rigid regions, combined with a method involving core plates stacking and lamination with PTFE spacers to support flexible and rigid regions, enhances the pressure-resistant strength of the solder-resist layer and prevents damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional one-time pressing method is used for manufacturing rigid-flex circuit board with flying-tail structure, then manufacturing process is simple, but solder-resist layer is easily damaged
Solution Approach 1:
The method applies preliminary action by performing multiple pressing operations at different stages: first pressing the flexible circuit board to the rigid circuit board before solder-resist coating, and second pressing after solder-resist coating. This staged approach allows the solder-resist layer to be applied on a pre-positioned structure, preventing damage during the positioning process while maintaining manufacturing simplicity through standardized pressing procedures at each stage.
2Productivity
If traditional manufacturing method is used, then production time is short, but qualified rate is low due to solder-resist layer damage
Solution Approach 1:
The manufacturing process is segmented into distinct stages: first pressing the flexible and rigid circuit boards together before solder-resist coating, then applying solder-resist, and finally performing a second pressing. This segmentation allows each operation to be optimized independently - the first pressing ensures precise positioning, the solder-resist coating can be applied without damage risk, and the second pressing secures the final structure, thereby maintaining high production speed while improving qualified rate.
3Device complexity
If solder-resist layer is applied before pressing, then coating process is simple, but layer is damaged during high temperature and pressure pressing
Solution Approach 1:
The method reverses the conventional sequence by performing the pressing action before applying the solder-resist coating. The flexible circuit board is first pressed to the rigid circuit board to establish the flying-tail structure, then the solder-resist coating is applied to the already-positioned board, and finally a second pressing secures everything. This preliminary positioning eliminates the risk of solder-resist layer damage during pressing while keeping the coating process simple.
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 solution significantly improves the qualified rate of rigid-flex circuit boards by protecting the solder-resist layer from damage during the manufacturing process, ensuring higher reliability and performance.
Implementation Method 1
polyetherimide covering films are attached to solder-resist areas of adjacent end surfaces of the respective second parallel planar rigid regions
Implementation Method 2
providing a PTFE spacer between adjacent flexible regions and between adjacent second parallel planar rigid regions of the sub-boards, laminating all the sub-boards
Implementation Method 3
stacking and laminating the core plates to make the sub-boards
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for manufacturing a rigid-flex circuit board having a flying-tail structure is disclosed, including the following steps: step 1, making core plates required by respective sub-boards, the core plates required by the respective sub-boards including at least one flexible core plate and at least one rigid core plate, and stacking and laminating each of the core plates to make the sub-boards, the number of the sub-boards being equal to the number of second rigid regions, with each of the sub-boards including a partial first rigid region, one flexible region and one second rigid region; step 2, stacking all the sub-boards made in the step 1, and attaching polyetherimide covering films to solder-resist areas of adjacent end surfaces of the respective second rigid regions; and step 3, providing a PTFE spacer between adjacent flexible regions and between adjacent second rigid regions, laminating all the sub-boards that has been processed in the step 2, and the partial first rigid regions of the sub-boards being laminated together to form a first rigid region of the rigid-flex circuit board. A rigid-flex circuit board having a flying-tail structure is further disclosed. The method for manufacturing the rigid-flex circuit board having the flying-tail structure can effectively prevent the solder-resist layer from being damaged.