Polyamic Acid Layered Body for Easy Inorganic Substrate Peeling
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Solution Overview
Problem
Existing methods for peeling off highly heat-resistant films from inorganic substrates, such as polyimide-based resins, are complex, time-consuming, and costly, or require high peel strengths that can damage the underlying devices.
Innovation Solution
A layered body comprising an inorganic substrate and a polyamic acid heat-cured product with a weight average molecular weight of 30,000 or more and a peel strength of 0.3 N/cm or less, which can be easily peeled off after heating at 250°C, and optionally includes a silane coupling agent layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional methods (laser irradiation, Joule heating, induction heating, flash light) are used to peel off the highly heat-resistant film from the inorganic substrate, then the film can be separated, but the process becomes complicated, time-consuming, and expensive
Solution Approach 1:
The patent changes the molecular weight parameter of the polyamic acid to 30,000 or more, which fundamentally alters the peeling behavior. This parameter change enables the film to be easily peeled from the inorganic substrate through simple mechanical means without requiring complex laser, heating, or induction facilities, thus resolving the contradiction between peeling effectiveness and process complexity
Solution Approach 2:
The patent employs a disposable inorganic substrate that can be easily separated from the flexible substrate after the flexible substrate is fully formed and utilized. The inorganic substrate serves its purpose as a carrier during manufacturing and then is discarded, eliminating the need for complex permanent bonding or sophisticated peeling facilities
2Strength
If the polyimide film is firmly attached to the inorganic substrate, then adhesion is strong, but it becomes difficult to mechanically peel off without damaging the device
Solution Approach 1:
The patent changes the molecular weight parameter of the polyamic acid to 30,000 or more, which creates an optimal balance between adhesion during processing and ease of peeling after device formation. This parameter adjustment ensures the film adheres strongly enough to serve as a stable carrier but can be easily separated afterward without requiring excessive force that would damage the device
Solution Approach 2:
The patent creates a dynamic adhesion system where the bond strength between the polyamic acid film and inorganic substrate is sufficient during the manufacturing phase but becomes easily breakable after device formation. This dynamic characteristic allows the system to adapt from requiring strong adhesion during processing to requiring easy separation during peeling, resolving the contradiction between these opposing requirements
3Strength
If a silane coupling agent is used to attach the polyimide film to the inorganic substrate, then adhesion is controlled, but the peel strength remains as strong as 1 N/cm or more making mechanical peeling difficult
Solution Approach 1:
The patent changes the molecular weight parameter of the polyamic acid to 30,000 or more, which fundamentally overrides the adhesion characteristics provided by silane coupling agents. This parameter change reduces the peel strength to 0.03 N/cm or less, enabling easy mechanical peeling while still maintaining sufficient adhesion during the manufacturing process, thus resolving the contradiction between controlled adhesion and peeling ease
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 layered body allows for easy mechanical separation of the polyamic acid heat-cured product from the inorganic substrate without damaging the device, while maintaining flexibility and transparency, and reduces the risk of warpage due to thermal expansion differences.
Implementation Method 1
a polyimide-based resin or the like is formed on an inorganic substrate
Data Source
AI summary
Provided is a layered body including glass and a polyamic acid heat-cured product that is readily releasable from an inorganic substrate after being heated at 250° C. A layered body including an inorganic substrate and a polyamic acid heat-cured product, the layered body being characterized by a weight average molecular weight of 30,000 or greater for the polyamic acid, and a peel strength of 0.3 N/cm or weaker between the polyamic acid heat-cured product layer and the inorganic substrate, after the layered body has been heated at 250° C.