Release Sheet Resin Film Balancing Viscosity and Dewetting Control
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Solution Overview
Problem
Resin films containing particles with diameters larger than the film thickness suffer from the expansion of dewetting spots, leading to quality deterioration and reduced releasing properties, which existing technologies fail to address effectively.
Innovation Solution
A release sheet-attached resin film comprising a resin composition with large-diameter particles (diameter > 2A) and specific ranges of release resistance and complex viscosity, ensuring a resin coverage rate of 95% and dewetting expansion rate ≤ 6, along with a release rate ≥ 95%, to suppress dewetting spot formation and maintain high quality and releasing properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If particles with diameters larger than the resin thickness are used, then specific functions such as thermal conductivity can be imparted to the resin film, but dewetting spots form and expand over time, leading to quality deterioration
Solution Approach 1:
The patent applies parameter changes by precisely controlling the release resistance of the release sheet and the complex viscosity of the resin composition within specific numerical ranges. This allows the resin to properly wet and adhere around large-diameter particles during coating, preventing dewetting spot formation while maintaining the functional properties imparted by the particles.
2Reliability
If resin viscosity is increased to enhance retention on the release sheet, then releasing property deteriorates, but if viscosity is decreased for good releasing property, then retention on the release sheet is reduced
Solution Approach 1:
The patent resolves this contradiction by defining a specific numerical range for complex viscosity at 25°C and establishing a precise mathematical relationship between release resistance and complex viscosity. This controlled parameter combination ensures the resin has sufficient viscosity to retain properly on the release sheet during coating while maintaining adequate releasing property for subsequent processing.
3Manufacturing precision
If the release resistance is increased to suppress dewetting spots, then resin coating uniformity improves, but releasing property of the resin from the release sheet deteriorates
Solution Approach 1:
The patent resolves this contradiction by establishing a specific mathematical relationship between release resistance and complex viscosity within defined numerical ranges. This balanced parameter combination allows the release resistance to be sufficiently high to suppress dewetting spots and ensure coating uniformity, while the corresponding complex viscosity value ensures the releasing property remains adequate for subsequent processing steps.
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 resin film effectively suppresses dewetting spot expansion and maintains high quality and good releasing properties, even with large-diameter particles, by balancing release resistance and complex viscosity within specified ranges.
Implementation Method 1
a resin composition containing large-diameter particles and a release sheet with one side coated therewith
Implementation Method 2
the complex viscosity [Y] (MPa·s) of the resin composition at 25°C are within the ranges defined by the following equations
Data Source
AI summary
In view of the above circumstances, the main object of the present invention is to provide a resin film that includes resin containing particles with diameters sufficiently large relative to the thickness of the resin film, which are disposed on one side of a release sheet, and that, in spite of it, suffers less from the expansion of dewetting spots, has high quality, and exhibits good releasing property from the release sheet. A release sheet-attached resin film comprising a resin composition of the components [A] to [D] specified below and a release sheet with one side coated therewith, and having the feature (I) described below, wherein the component [D] is particles and accounts for 10 to 30 mass% of the resin composition: [A] epoxy resin, [B] thermoplastic resin [C] curing agent, [D] particles including large-diameter particles having diameters larger than 2A, wherein A denotes the average resin thickness in the resin film, (I) the release resistance [X] (mN/20 mm) of the surface of the release sheet to be coated with the resin and the complex viscosity [Y] (MPa·s) of the resin composition at 25°C are within the ranges defined by the following equations (1)-1 to (1)-4. 500≦X≦40001−10.01≦Y≦2.11−2Y≧0.14e−7×10−4x1−3Y≦3.00e−7×10−4x1−4