Kyosuke Michigami | Panasonic Industry: Can we drop substrate modulus by three orders of magnitude without sacrificing mechanical reliability?
00:05:20 - 00:06:07
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Summary of the clip:
Can we drop substrate modulus by three orders of magnitude without sacrificing mechanical reliability?
Conventional polyimide substrates exhibit a tensile modulus of approximately 7 GPa, which provides excellent thermal stability but severely limits the pliability and form factors required for advanced wearable electronics and skin-conformal displays. To overcome this limitation, Panasonic developed "Copper Clad Stretchable" (CCS) materials that dramatically lower the modulus to just 7 MPa while maintaining structural integrity.
This massive reduction in modulus allows the substrate to undergo complex mechanical deformations, including stretching, twisting, and tight bending, without experiencing delamination or copper trace failure. By transitioning from gigapascal-range rigidity to megapascal-range elasticity, developers can design truly conformal systems.
The crosslinked chemistry of the CCS material ensures that despite this ultra-low modulus, the polymer network remains thermally robust, resisting deformation under high-temperature assembly processes that would completely melt typical thermoplastic elastomers.
In this short video, you can learn:
* The stark mechanical differences between conventional 7 GPa polyimide and Panasonic's new 7 MPa CCS material.
* How reducing substrate modulus enables advanced mechanical form factors including multi-axis stretching and twisting.
* Why maintaining low modulus and elasticity is the key to achieving ultra-reliability in next-generation skin-conformal electronics.
📋 **Clip Abstract** This clip contrasts the mechanical properties of conventional polyimide substrates with Panasonic's newly developed Copper Clad Stretchable (CCS) materials. By reducing the modulus from 7 GPa to 7 MPa, the material supports extreme mechanical deformations while maintaining a robust crosslinked polymer network.
#CopperCladStretchable, #LowModulusSubstrates, #CrosslinkedElastomers, #StretchableCopperTraces, #SkinConformalElectronics, #FlexibleElectronics
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00:09:26 - 00:10:53
How do you process stretchable substrates using conventional subtractive PCB lines and lead-free SMT reflow?
How do you process stretchable substrates using conventional subtractive PCB lines and lead-free SMT reflow?
Implementing stretchable substrates into volume production requires compatibility with existing printed circuit board manufacturing infrastructure. Panasonic's CCS and stretchable coverlay technology integrates seamlessly into a standard subtractive PCB process, including mechanical drilling, desmearing, copper plating for via-hole connections, and chemical wet etching.
A key challenge is managing dimensional stability during high-temperature steps; this is resolved using a specialized polyimide release liner that secures the dimensions of the stretchable layer. The coverlay is first laminated at a mild 80°C and then fully cured at 180°C to establish a highly crosslinked thermoset network.
Once fully cured, the resulting stretchable board exhibits excellent thermal resistance, allowing it to survive lead-free SAC305 SMT reflow profiles peaking at 240°C without any delamination or trace damage, clearing the path for standard automated component mounting.
In this short video, you can learn:
* The step-by-step subtractive PCB process flow for Panasonic's stretchable copper-clad laminate.
* How a temporary polyimide release liner maintains dimensional stability during critical high-temperature manufacturing steps.
* The specific lamination, curing, and SAC305 reflow parameters required to successfully mount surface-mount devices (SMDs) on stretchable boards.
📋 **Clip Abstract** This segment details the manufacturing processability of Panasonic's stretchable circuit materials within a conventional subtractive PCB line. It outlines how the combination of a temporary release liner and thermosetting polymer chemistry enables the stretchable boards to withstand standard 240°C SAC305 SMT reflow.
#StretchableCopperCladLaminate, #SubtractivePCBProcessing, #SAC305Reflow, #PolyimideReleaseLiner, #FlexibleHybridElectronics, #StretchableElectronics
00:06:52 - 00:08:19
How does a stretchable coverlay prevent rapid electromigration and trace failure under high humidity and bias?
How does a stretchable coverlay prevent rapid electromigration and trace failure under high humidity and bias?
Reliability of flexible and stretchable circuits in humid environments depends heavily on the protective coverlay's ability to encapsulate fine-pitch copper traces without leaving voids. Panasonic's stretchable coverlay utilizes a flowable thermosetting resin formulation that completely fills high-aspect-ratio 100-micron gaps between adjacent traces during lamination, eliminating pathways for moisture accumulation.
To validate its environmental protection capabilities, a biased humidity test was conducted at 60°C and 90% relative humidity under a constant 5V bias. Unprotected comb patterns suffered rapid electrochemical migration and failed due to open circuits in less than an hour of exposure.
In contrast, circuits protected by the stretchable coverlay maintained their insulation resistance and continued to function flawlessly after 1,000 hours of continuous testing. This demonstrates that the coverlay provides a robust, hermetic-like moisture barrier even when subjected to prolonged environmental stress.
In this short video, you can learn:
* The encapsulation performance of stretchable coverlays in filling narrow 100-micron copper trace gaps without voids.
* The performance delta between protected and unprotected stretchable circuits under biased highly accelerated stress testing (HAST).
* Why void-free, crosslinked thermoset coverlays are mandatory for long-term electrical reliability in wearable environments.
📋 **Clip Abstract** This clip examines the environmental reliability and insulation properties of Panasonic's stretchable coverlay material. It shows how void-free trace encapsulation protects copper circuits from electromigration during a 1,000-hour biased humidity test at 60°C and 90% RH.
#StretchableCoverlay, #ElectrochemicalMigration, #VoidFreeEncapsulation, #ThermosetResin, #FlexibleHybridElectronics, #WearableElectronics