AlSiC Carrier Bonding via Glass Primer Layer
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Solution Overview
Problem
The existing methods for connecting circuit carriers to aluminum/silicon carbide metal matrix composite (AlSiC-MMC) materials face challenges due to non-wetting issues with nickel coatings, resulting in suboptimal adhesion and connection strength, as nickel does not adhere well to silicon carbide, carbon, and aluminum oxide surfaces.
Innovation Solution
A method involving the application of a glass-containing bonding layer on the AlSiC-MMC surface, which forms a strong material-fit connection with a circuit carrier, eliminating the need for nickel coatings by using a glass-based bonding layer that adheres well to the composite material, even with contaminants like aluminum oxide and silicon carbide, and a connecting layer that bonds with the metallization layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a nickel coating is applied to the AlSiC-MMC carrier surface to improve solderability, then the solderability is enhanced, but the adhesion strength is reduced because nickel does not wet on silicon carbide, carbon, and aluminum oxide surfaces
Solution Approach 1:
The patent introduces a special primer coating as an intermediary layer between the AlSiC-MMC carrier surface and the nickel solderability coating. This primer contains specific chemical components that can chemically bond to both the substrate surface (silicon carbide, carbon, aluminum oxide) and the nickel layer, thereby mediating the adhesion problem while maintaining solderability.
Solution Approach 2:
The patent modifies the surface properties by applying a primer coating that changes the chemical and physical parameters of the surface. This primer alters the surface energy, roughness, and chemical composition to enable better wetting and adhesion of subsequent nickel and solder layers, transforming the non-wetting surface into a wettable one.
2Strength
If a nickel coating is applied to improve connection strength, then the connection between solder and carrier is enhanced, but the overall connection quality deteriorates due to poor adhesion to the substrate
Solution Approach 1:
The special primer acts as a reliable intermediary that ensures consistent and strong adhesion between the substrate and the nickel-solder system. This mediator layer provides a stable chemical bridge that eliminates the unreliability caused by poor wetting, ensuring dependable connection quality across production batches.
Solution Approach 2:
The patent applies the special primer as a preliminary action before depositing the nickel and solder layers. This pre-treatment prepares the surface in advance to ensure optimal adhesion conditions, preventing future connection failures and ensuring consistent connection quality throughout the manufacturing process.
3Reliability
If the carrier surface is left uncoated to maintain material purity, then the AlSiC-MMC material properties are preserved, but the solderability and adhesion are insufficient
Solution Approach 1:
The patent applies the special primer coating only to specific surface areas where soldering and connection are required, rather than coating the entire carrier. This localized treatment preserves the bulk material properties and surface characteristics of the AlSiC-MMC where coating is not needed, while providing enhanced solderability only where joints are formed.
Solution Approach 2:
The solution creates a composite surface structure consisting of the AlSiC-MMC substrate combined with a multi-layer coating system (primer + nickel + solder). This composite approach maintains the superior mechanical and thermal properties of the AlSiC-MMC base material while adding the necessary surface functionality for soldering and adhesion through the layered composite structure.
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 enables a strong and reliable connection between the AlSiC-MMC carrier and the circuit carrier, enhancing the bonding strength and eliminating the need for nickel layers, thus improving the overall connection quality.
Implementation Method 1
A bonding layer, which contains a glass, is generated on the surface section of the carrier. A material-fit connection between this bonding layer and the circuit carrier is produced by means of a connecting layer. The glass contained in the bonding layer leads to a very strong connection to the AlSiC-MMC material.
Data Source
AI summary
According to a method for producing a circuit carrier arrangement, a carrier which has a surface section formed by an aluminum/silicon carbide metal matrix composite material is provided. A circuit carrier, which has an insulation carrier with a lower side onto which a lower metallization layer is applied, is also provided. A bonding layer, which contains a glass, is generated on the surface section. A material-fit connection between the bonding layer and the circuit carrier is produced by means of a connecting layer.