Metal-Ceramic Substrate Contact Layout for Thermal Shock Resistance
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Solution Overview
Problem
Metal-ceramic substrates in power electronics face challenges with thermal shock resistance due to differing thermal expansion coefficients of metal and ceramic materials, leading to potential detachment of the metal layer from the ceramic body during temperature changes.
Innovation Solution
A metal-ceramic substrate design featuring a ceramic body with a metal layer that includes a structuring region with a high proportion of solid material near the ceramic surface, characterized by a specific geometric ratio of solid to total area in cross-section, and a silver contact area to enhance bonding and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If silver plating is applied to the metal-ceramic substrate to facilitate chip connection, then ease of manufacture is improved, but thermal shock resistance deteriorates due to weak points and detachment
Solution Approach 1:
The patent applies different material properties to different regions of the substrate. The center region maintains the metal-ceramic bond structure for thermal stability, while the peripheral region incorporates silver plating for ease of chip connection. This local differentiation allows each region to optimize its function without compromising the other.
Solution Approach 2:
The substrate surface is divided into distinct functional zones: a central bonding area with metal-ceramic interface for thermal management, and peripheral contact areas with silver plating for electrical connection. This segmentation prevents the silver plating from compromising the thermal shock resistance of the bonding interface while still providing the necessary electrical connectivity.
2Use of energy by moving object
If the metal layer is bonded to the ceramic body, then thermal conductivity is improved, but thermal shock resistance deteriorates due to different thermal expansion coefficients causing peeling
Solution Approach 1:
The patent modifies the bonding interface structure by creating a graded transition zone between the metal and ceramic layers. This gradual parameter change in material composition and density reduces the thermal expansion mismatch, allowing the bond to withstand repeated temperature cycling without peeling while maintaining effective thermal conduction.
Solution Approach 2:
The bonding interface utilizes a composite structure combining metal and ceramic materials with complementary properties. The metal layer provides thermal conductivity, while the ceramic provides thermal stability and low expansion. The engineered interface between these composite materials manages the thermal expansion differential, preventing delamination during thermal shock.
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 design significantly improves thermal shock resistance by maintaining the metal layer's adherence to the ceramic body, even under extreme temperature fluctuations, compared to traditional methods where silver plating can lead to weak points and detachment.
Implementation Method 1
When the copper foil treated in this way is applied to a ceramic body and the composite is heated, the copper compound melts and wets the surface of the ceramic body
Implementation Method 2
the copper compound melts and wets the surface of the ceramic body, creating a stable, integral bond
Implementation Method 3
The role of the active metal is to react with the ceramic material, thus enabling the ceramic material to bond to the remaining solder to form a reaction layer
Implementation Method 4
They are a crucial element in the construction of electronic components and ensure the rapid dissipation of large amounts of heat during operation
Implementation Method 5
Due to the different thermal expansion coefficients of the metal and the ceramic, repeated temperature changes can lead to the metal layer peeling off from the ceramic body
Data Source
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AI summary
The invention relates to a metal-ceramic substrate and an electronic component comprising a metal-ceramic substrate.The metal-ceramic substrate comprises: a) a ceramic body having a principal extension plane, b) a metal layer bonded planarly to the ceramic body, the metal layer having a structuring area comprising (i) regionally solid material and (ii) regionally non-solid material, and c) a contact area arranged on the metal layer. Silver, characterized in that, in a cross-section through the metal-ceramic substrate perpendicular to the principal extension plane, the structuring area has a geometry satisfying the following requirement: ABCDsolid/ABCDtotal>70%, where A (BCDtotal) represents the total area of the triangle defined by points B, C, and D, and A (BCDsolid) represents the area of the triangle defined by points B, C, and D occupied by solid material.