Thick-Circuit Laminate Autoclave Curing to Prevent Insulating-Layer Voids
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Solution Overview
Problem
In the production of laminates with thick circuit patterns, uneven pressure application during hot pressing leads to insufficient pressurization in gap portions, resulting in voids and defects in the insulating layer, which are exacerbated by increased gap depth.
Innovation Solution
A method involving the use of a semi-cured resin composition interposed between a metal base substrate and circuit pattern, followed by autoclave curing with controlled temperature and pressure to ensure uniform pressurization and gas discharge, including a compressive force application step to enhance resin density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If hot pressing is carried out with conventional pressure application, then the resin composition at conductive portions is pressurized, but the gap portion between conductive portions receives insufficient pressurization
Solution Approach 1:
A cushion material is introduced as an intermediary element between the circuit pattern and the resin composition. This cushion material transmits pressure uniformly to the resin composition in gap portions where direct pressure from the circuit pattern is insufficient, ensuring adequate pressurization without compromising the insulating layer quality.
Solution Approach 2:
The invention changes the physical state and properties of the resin composition by using a semi-cured state with specific viscosity characteristics. This parameter change allows the resin to flow and fill gap portions effectively under pressure, achieving uniform pressurization and eliminating voids while maintaining insulation performance.
2Reliability
If the circuit pattern thickness is increased to reduce resistance and improve heat dissipation, then the gap depth increases causing more severe insufficient pressurization
Solution Approach 1:
The cushion material serves as a pressure transmission mediator that compensates for the increased gap depth caused by thicker circuit patterns. It ensures that even in deep gap portions, adequate pressure is applied to the resin composition, preventing void formation while maintaining the electrical conductivity benefits of thick circuit patterns.
Solution Approach 2:
The resin composition is prepared in a semi-cured state with optimized viscosity before application. This preliminary preparation ensures that the resin has the right flow characteristics to penetrate and fill gap portions effectively, preventing voids even when gap depth is increased by thicker circuit patterns.
3Stress or pressure
If cushion material is used to cover surface irregularities, then pressurization is improved, but it is difficult to sufficiently reach the depth of deep gaps
Solution Approach 1:
The invention changes the rheological parameters of the resin composition by using a semi-cured state with specific viscosity. This parameter change enables the resin to flow into and fill deep gap portions effectively, overcoming the limitation of conventional cushion materials that cannot reach deep gaps.
Solution Approach 2:
The resin composition itself acts as the pressure transmission medium in gap portions, utilizing its flow characteristics to fill and pressurize the gap depth. This self-service mechanism eliminates the need for extended cushion materials and directly addresses the deep gap problem through the resin's inherent properties.
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
Prevents defects in the insulating layer, ensuring sufficient insulation and withstand voltage, with the laminate maintaining integrity under high thermal stress.
Implementation Method 1
a step of exhausting an inside atmosphere of the film and increasing a temperature and a pressure inside the autoclave to cure the semi-cured resin composition
Implementation Method 2
a step of exhausting an inside atmosphere of the film and increasing a temperature and a pressure inside the autoclave
Implementation Method 3
a step of applying a compressive force to the semi-cured resin composition, the step being carried out before the step of preparing the laminate before press bonding is performed
Data Source
AI summary
The present invention relates to a laminate that includes a circuit pattern having a thickness of 0.8 mm or more, and a method for producing a laminate capable of preventing defects occurring in an insulating layer is proposed. A method for producing a laminate that is formed by lamination of a metal base substrate, an insulating layer formed by curing a resin composition, and a circuit pattern having a thickness of 1 mm or more includes a step of preparing a laminate before press bonding in which a semi-cured resin composition is interposed between the metal base substrate and the circuit pattern, a step of covering the laminate before press bonding with a film and placing the laminate before press bonding inside an autoclave and a step of exhausting an inside atmosphere of the film and increasing a temperature and a pressure inside the autoclave to cure the semi-cured resin composition.