Ceramic Substrate with Inclined Protrusions for Bonding Strength
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Solution Overview
Problem
Ceramic AMB substrates face issues with cracking and delamination under rapid temperature changes due to the degradation of electrical characteristics and bonding strength caused by the formation of dimples on the metal layer, which also limits their application in micro-scale patterns and increases costs with the use of high-strength materials like Si3N4 and SiC.
Innovation Solution
The formation of inclined protrusions, including tapered and multi-stepped protrusions, on the boundary surface of the metal layer bonded to the ceramic base, which increases bonding strength and area, thereby improving electrical characteristics and resistance to cracking and delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple dimples are formed along the boundary surface of the metal layer to prevent cracking and delamination, then reliability under rapid temperature change is improved, but the area of the metal layer decreases leading to degradation in electrical characteristics
Solution Approach 1:
The boundary surface of the metal layer is segmented into multiple inclined protrusions distributed along the boundary, creating localized bonding enhancement zones without requiring extensive dimple coverage. This segmentation approach provides crack resistance while preserving overall metal layer area and electrical characteristics.
Solution Approach 2:
Instead of creating dimples that extend deeply into the metal layer (vertical dimension), the invention forms inclined protrusions that extend laterally from the boundary surface. This dimensional change allows bonding enhancement without significant area loss, as the protrusions utilize the lateral space along the boundary rather than consuming vertical metal layer thickness.
2Reliability
If high-strength materials like Si3N4 and SiC are applied to the ceramic substrate to prevent cracking and delamination, then reliability is improved, but product cost increases
Solution Approach 1:
Rather than applying high-strength materials uniformly across the entire ceramic substrate, the invention creates localized bonding enhancements only at the boundary surface where cracks and delamination occur. The inclined protrusions concentrate bonding strength precisely where needed, avoiding the cost of upgrading the entire substrate material to expensive Si3N4 or SiC.
Solution Approach 2:
The invention changes the geometric parameters of the metal layer boundary (creating inclined protrusions with specific angles and dimensions) rather than changing the material parameters. This parameter modification achieves enhanced bonding strength through optimized geometry alone, eliminating the need for costly material substitutions while maintaining reliability.
3Reliability
If multiple dimples are formed along the boundary surface of the metal layer, then cracking and delamination are prevented, but the electrical characteristics such as electric conductivity and thermal resistance deteriorate
Solution Approach 1:
Instead of forming dimples across the entire metal layer surface, the invention applies the bonding enhancement structure only partially - specifically at the boundary surface where stress concentration occurs. This partial action provides sufficient crack resistance while leaving the majority of the metal layer area intact, thereby preserving electrical conductivity and thermal resistance.
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 ceramic substrate with inclined protrusions maintains high electrical and thermal performance while preventing delamination, allowing for reliable use in various applications, including micro-scale patterns, and reduces post-processing costs by simplifying the etching process.
Implementation Method 1
a ceramic AMB substrate is manufactured through active metal brazing (AMB), which is a form of brazing which allows metal to be directly joined to the surface of the ceramic base
Implementation Method 2
etching a predetermined portion of the boundary surface of the metal layer with an etching solution
Data Source
AI summary
A ceramic substrate is provided in which an inclined protrusion is formed on boundary surface of a metal layer bonded to a ceramic base so as to increase bonding strength; and a manufacturing method therefor. The inclined protrusion may include: a tapered protrusion and a multi-stepped protrusion formed on the boundary surface of the metal layer according to an interval between the metal layer bonded to the ceramic base and a neighboring metal layer, wherein a multi-stepped protrusion having an inclination angle within a predetermined angle range with respect to the ceramic base may be formed on the boundary surface of the metal layer where stress is concentrated, such as the short edge, apex, corner, and the like, and a tapered protrusion may be formed on a remaining portion of the boundary surface of the metal layer.