Stretchable Circuit Board Joining Strength via Rough Surface Interlocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stretchable circuit boards face challenges in achieving sufficient joining strength between stretchable and non-stretchable portions, leading to potential detachment when subjected to force, particularly during attachment to uneven surfaces.
Innovation Solution
A stretchable circuit board design featuring a stretchable portion with a stretchable base and wiring, and a non-stretchable portion with a base substrate and draw-out wiring, where the first main surfaces are joined with a rough surface having projections and depressions, enhancing electrical connectivity and mechanical bonding through laminate connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the stretchable circuit board is bonded through laminate connection with compression and heating, then the joining strength between stretchable and non-stretchable portions is improved, but the complexity of the manufacturing process increases
Solution Approach 1:
The invention applies preliminary action by pre-forming protrusions and recesses on the bonding surfaces before the laminate connection process. These geometric features are created in advance on the stretchable substrate and non-stretchable substrate, respectively, so that when the substrates are bonded together through compression and heating, the protrusions fit into the recesses to automatically enhance joining strength without requiring additional manufacturing steps or complex processes.
2Adaptability or versatility
If the stretchable substrate is subjected to force during attachment to uneven surfaces or during re-bonding, then the adaptability to uneven surfaces is improved, but the reliability of the bonding connection deteriorates due to potential detachment
Solution Approach 1:
The invention applies beforehand cushioning by pre-designing the bonding interface with complementary protrusions and recesses that interlock together. This geometric interlocking structure is built into the bonding connection before any forcing or re-bonding operations occur. When the stretchable substrate is subjected to force during attachment to uneven surfaces or during re-bonding operations, the interlocked protrusion-recess structure provides mechanical reinforcement that prevents detachment, thereby maintaining bonding reliability despite the applied forces.
3Adaptability or versatility
If the circuit board has both stretchable and non-stretchable portions bonded together, then the functionality for both sensing and signal output is improved, but the uniformity of the substrate structure deteriorates
Solution Approach 1:
The invention applies local quality by creating distinct regions with different properties within the overall circuit board structure. The stretchable portion is designed with elastomer material and corresponding wiring for sensing applications requiring deformation, while the non-stretchable portion uses rigid material for stable signal output. The protrusion-recess bonding structure locally connects these dissimilar regions, allowing each portion to maintain its specific functional characteristics while being integrated into a unified circuit board system.
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
The solution provides increased joining strength between the stretchable and non-stretchable portions, ensuring the circuit board remains intact even when stretched to 70% elongation, preventing detachment and maintaining functionality.
Implementation Method 1
the first main surface of the stretchable base and the first main surface of the base substrate are joined with each other... The first main surface of the base substrate is a rough surface having a projection and a depression
Implementation Method 2
Bonding of the base to the film is performed through laminate connection in which both are compressed and heated
Data Source
AI summary
A stretchable circuit board includes: a stretchable portion 50 that includes a stretchable base 53 haying stretchability and a stretchable wiring 55 formed on a first main surface 53a of the stretchable base 53 and having stretchability; and a non-stretchable portion 30 that includes a base substrate 34 having stretchability lower than that of the stretchable base 53 and a draw-out wiring 35 formed on a main surface 32b of the base substrate 34, in which the main surface 53a of the stretchable portion 53 and the main surface 32b of the base substrate 34 are joined with each other, and the stretchable wiring 55 and the draw-out wiring 35 are electrically connected with each other. In addition, the main surface 32b of the base substrate has a rough surface with projections and depressions.