Metal Oxide Heat-Dissipating Circuit Board With Thin Insulation
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Solution Overview
Problem
Conventional heat-dissipating circuit boards using ceramics for insulating layers face challenges with insufficient thermal conductivity due to processing difficulties, adhesive thermal conductivity issues, and high porosity, leading to poor heat dissipation and insulation properties, especially in high-temperature applications.
Innovation Solution
A heat-dissipating circuit board with a metal oxide layer formed by reacting a coating liquid containing an aluminum complex on a copper or aluminum alloy, using a method that ensures a thin film with low porosity and high volume resistivity, bonded to a metal material with controlled surface roughness to enhance close contact and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thermal calcination method is used to form a ceramic insulating layer, then insulation properties are improved, but the thickness cannot be reduced to 150 μm or less and thermal conductivity remains insufficient
Solution Approach 1:
The patent changes the formation method parameters from thermal calcination to sputtering deposition, enabling precise thickness control down to nanometer scale while maintaining insulation properties. The sputtering process allows thickness to be reduced to 150 μm or less by controlling deposition time and rate, resolving the contradiction between insulation reliability and manufacturing precision.
2Strength
If an adhesive layer is used to bond ceramics to metals, then bonding is achieved, but thermal conductivity decreases due to adhesive properties
Solution Approach 1:
The patent extracts and removes the adhesive layer from the structure by directly forming the insulating layer on the metal substrate through sputtering. This eliminates the thermal barrier introduced by adhesives while maintaining bonding strength through direct physical and chemical bonding between the insulating layer and metal substrate.
Solution Approach 2:
The patent merges the insulating layer formation and substrate bonding processes into a single integrated step. The insulating layer is directly deposited on the metal substrate, combining the functions of insulation and bonding while eliminating the thermal resistance of separate adhesive layers.
3Ease of manufacture
If thermal spraying method is used to form insulating film, then film formation is achieved, but pinholes are formed and porosity is high reducing thermal conductivity
Solution Approach 1:
The patent replaces the mechanical thermal spraying process with a sputtering deposition process. Sputtering produces dense, pinhole-free films with controlled microstructure, eliminating the porosity and defects inherent in thermal spraying while maintaining ease of manufacture through a well-established deposition technique.
4Reliability
If anodic oxidation method is used to form alumina layer, then insulation is achieved, but hexagonal columnar cavities create high porosity and poor thermal conductivity
Solution Approach 1:
The patent changes the microstructure parameters of the insulating layer by using sputtering instead of anodic oxidation. The sputtering process produces a dense, non-porous amorphous or fine-grained crystalline structure without the hexagonal columnar cavities characteristic of anodized alumina, thereby improving thermal conductivity while maintaining insulation 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
The solution achieves high heat dissipation and insulation properties with a thin metal oxide layer that maintains durability even at high temperatures, preventing cracking and ensuring effective heat transfer between the metal material and the conductive metal layer.
Implementation Method 1
an insulating layer which is a metal oxide layer having a compositional formula: AlxOyTz... formed by reacting a coating liquid containing an aluminum complex on the metal material
Implementation Method 2
heat-dissipating circuit board... release heat generated by electronic parts such as semiconductor chips to the outside of the system... effective heat transfer between the metal material and the conductive metal layer
Data Source
AI summary
According to the present invention, a heat-dissipating circuit board is formed by providing a metal material adjacent to one surface of an insulating layer and providing a conductive metal layer to the other surface of the insulating layer. The metal material is a sheet of copper or a copper alloy or aluminum or an aluminum alloy and is 0.2-20 mm thick. The insulating layer is a metal oxide layer that has the composition AlxOyTz, is 0.2-30 μm thick, has a volume resistivity of at least 1000 GΩ·cm, and has a porosity of no more than 10%. The heat-dissipating circuit board has excellent heat-dissipation properties and insulation properties.