FRP Precursor Adhesion via Controlled Pressure Roll Temperature

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Solution Overview

Problem

Existing methods for producing FRP precursors for printed wiring boards face challenges with resin filling properties under atmospheric pressure, leading to void formation and poor workability, especially when using aggregates like aramid non-woven fabrics or thin glass papers.

Innovation Solution

A method involving adhering a thermosetting resin film to a glass fiber aggregate under atmospheric pressure using a pressure roll with controlled temperature and pressure conditions, specifically within the range of +10°C to +35°C and 0.4 to 1.0 MPa, to enhance resin filling properties and prevent resin spouting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a thermosetting resin is applied to the aggregate in advance using the Hand Lay-up method, then the workability in the process is improved and the load to a surrounding environment is lowered, but when an aggregate such as an aramid non-woven fabric without a calendar treatment, a thin glass paper, or a thin woven fabric is used, they are low in the strength as the aggregate; and thus, upon applying the varnish followed by solvent removal, drying, and thermal curing, the weight thereof outweighs the allowable load of the aggregate thereby resulting in a cut of the aggregate and a poor workability

Engineering Contradiction:
ImproveworkabilityVSAvoidaggregate strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent applies preliminary action by pre-calendaring the aggregate (aramid non-woven fabric, thin glass paper, or thin woven fabric) before resin application. This calendar treatment strengthens the aggregate structure in advance, enabling it to withstand the subsequent resin application, solvent removal, drying, and curing processes without cutting or breakage, thereby resolving the contradiction between improving workability and maintaining aggregate strength

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical parameter of the aggregate by subjecting it to calendar treatment, which modifies its mechanical properties and strength characteristics. This parameter change enables the aggregate to support the resin processing steps without failure, resolving the strength limitation of untreated thin aggregates

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If plural FRP precursors are produced from one aggregate by different coating conditions to satisfy different thickness and resin amount requirements, then the production conditions become cumbersome and loss of the material used in the production is significant, but producing FRP precursors with different resin amounts and curing times is necessary for printed wiring board applications

Engineering Contradiction:
Improveresin amount controlVSAvoidmaterial loss
Core Design Contradiction:
Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The patent applies preliminary action by pre-calendaring the aggregate to control its thickness and physical properties before resin application. This allows a single aggregate type to be used for producing multiple FRP precursor specifications with different resin amounts and curing times, eliminating the need for multiple aggregate types and reducing material loss while maintaining adaptability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent makes the aggregate universally applicable by calendar treatment, enabling one aggregate type to serve multiple functions in producing different FRP precursor specifications (different thicknesses, resin amounts, and curing times) for printed wiring boards, thereby reducing material loss and simplifying production

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 approach results in excellent resin filling properties into bulk voids of the aggregate, improving workability and reducing resin spouting from the aggregate's edge, thereby producing high-quality FRP precursors for printed wiring boards.

Implementation Method 1

press-adhering means for press-adhering the thermosetting resin film and the aggregate by heating

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

press-adhering means for press-adhering the thermosetting resin film and the aggregate by heating

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

press-adhering means for press-adhering the thermosetting resin film and the aggregate by heating

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP3603918B1Method for producing an FRP precursor for a printed wiring board
Publication Date: 2023.11.01 RESONAC CORP
  • EP3603918B1 patent drawingFigure 1

AI summary

In the method for adhering a resin film with an aggregate under an atmospheric pressure in which workability is excellent and spouting of the resin from an edge portion of the aggregate can be suppressed, the present invention provides a method for producing an FRP precursor with excellent resin filling property into bulk voids of the aggregate as well as a method for producing an FRP. Specifically, provided is the method for producing the FRP precursor by adhering a thermosetting resin film to one surface of an aggregate that is in a form of a sheet under an atmospheric pressure, wherein the method includes a process in which the thermosetting resin film and the aggregate are press-adhered by heating by means of a pressure roll having a temperature in a range of +5°C to +35°C relative to a temperature at which a minimum melt viscosity of the film is exhibited.