Multilayer Film Laminate for Low-Loss, Precise Laser Processing

Solution Overview

Problem

Existing films used in circuit boards for high-frequency communication equipment face challenges in maintaining low dielectric loss tangent and laser processing suitability, leading to issues with transmission loss and laser processing precision.

Innovation Solution

A film comprising layers A and B, where the dielectric loss tangent is 0.010 or less, and the absorbance ratio of layer B to layer A at 355 nm is between 0.45 and 1.00, with specific elastic modulus ratios and materials like liquid crystal polymer and aromatic polyester amide, enhancing laser processing suitability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a liquid crystal polymer is used as the insulating material to reduce dielectric loss tangent, then transmission loss is reduced, but laser processing precision deteriorates due to excessive overcutting

Engineering Contradiction:

Improvedielectric loss tangentVSAvoidlaser processing precision

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

The film is divided into two functional layers: layer A (liquid crystal polymer layer) for low dielectric loss and layer B (adhesive layer) for laser processing control. This segmentation allows each layer to independently perform its specific function without interfering with the other, resolving the contradiction between low dielectric loss and laser processing precision

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the film have different properties: layer A has low dielectric loss tangent for high-frequency signal transmission, while layer B has high UV absorbance for precise laser processing. This local differentiation of material properties allows the film to simultaneously satisfy both requirements in different areas

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If the absorbance of the adhesive layer is increased to improve laser processing suitability, then laser cutting precision is improved, but the dielectric loss tangent increases

Engineering Contradiction:

Improvelaser processing suitabilityVSAvoiddielectric loss tangent

Core Design Contradiction:

Manufacturing precisionVSLoss of energy

Solution Approach 1:

The film is divided into two functional layers: layer A (liquid crystal polymer layer) for low dielectric loss and layer B (adhesive layer) for laser processing control. This segmentation allows each layer to independently perform its specific function without interfering with the other, resolving the contradiction between low dielectric loss and laser processing precision

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the film have different properties: layer A has low dielectric loss tangent for high-frequency signal transmission, while layer B has high UV absorbance for precise laser processing. This local differentiation of material properties allows the film to simultaneously satisfy both requirements in different areas

Inventive Principle:

Principle #3Local quality

3Loss of energy

If a styrene-based polymer with inorganic filler is used to achieve low dielectric loss tangent, then transmission loss is reduced, but laser processing precision deteriorates

Engineering Contradiction:

Improvetransmission lossVSAvoidlaser processing precision

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

The film is divided into two functional layers: layer A (liquid crystal polymer layer) for low dielectric loss and layer B (adhesive layer) for laser processing control. This segmentation allows each layer to independently perform its specific function without interfering with the other, resolving the contradiction between low dielectric loss and laser processing precision

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The film uses a composite structure combining liquid crystal polymer (for low dielectric loss) with an adhesive layer containing UV absorbers (for laser processing control). This composite material approach allows the film to integrate multiple functions that cannot be achieved with a single material system

Inventive Principle:

Principle #40Composite materials

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 film achieves low dielectric loss tangent and improved laser processing suitability, reducing transmission loss and ensuring precise laser cutting without excessive overcutting, while maintaining excellent adhesiveness to circuit boards.

Implementation Method 1

a ratio of an absorbance of the layer B at a wavelength of 355 nm to an absorbance of the layer A at the wavelength of 355 nm is 0.45 or more and 1.00 or less

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentUS12358259B2Film and laminate

Publication Date: 2025.07.15 FUJIFILM CORP

AI summary

An embodiment of the present invention relates to a film including a layer A, and a layer B provided on at least one surface of the layer A, in which a dielectric loss tangent of the film is 0.010 or less, and a ratio of an absorbance of the layer B at a wavelength of 355 nm to an absorbance of the layer A at a wavelength of 355 nm is 0.45 or more and 1.00 or less, and a laminate including a film having a layer A and a layer B, and a metal layer or a metal wire on a B layer side of the film, in which a dielectric loss tangent of the film is 0.010 or less, and a ratio of an absorbance of the layer B at a wavelength of 355 nm to an absorbance of the layer A at a wavelength of 355 nm is 0.45 or more and 1.00 or less.