Power Module Substrate with Glass-Ag Paste for Low-Temperature Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power module substrates with heat sinks face high thermal loads and warpage issues due to high bonding temperatures during brazing, which can deteriorate the insulating layer and cause thermal stress and warpage in the substrate and metal parts.
Innovation Solution
A power module substrate with a heat sink is developed, featuring a glass-containing Ag paste base layer and a bonding layer of sintered metal material, allowing for bonding at lower temperatures and reducing thermal load and warpage by forming a strong interface between the metal layer and the heat sink through a glass layer and Ag layer configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If brazing is used to bond the metal layer and heat sink, then bonding strength is improved, but thermal load and warpage increase
Solution Approach 1:
The invention changes the bonding temperature parameter from high-temperature brazing (650°C) to low-temperature sintering (350-645°C). This is achieved by replacing traditional brazing materials with glass-containing Ag paste that can form strong bonds at lower temperatures, thereby reducing thermal load on the insulating layer and minimizing warpage while maintaining adequate bonding strength
Solution Approach 2:
The invention uses composite materials in the base layer, specifically glass-containing Ag paste that combines glass components (for low-temperature sintering and bonding) with Ag particles (for thermal conductivity and strength). This composite approach enables bonding at lower temperatures while maintaining the required mechanical and thermal properties
2Strength
If brazing is used to bond the metal layer and heat sink, then bonding strength is improved, but thermal deterioration of insulating layer increases
Solution Approach 1:
The invention changes the bonding temperature parameter from high-temperature brazing (650°C) to low-temperature sintering (350-645°C). This temperature reduction prevents thermal deterioration and damage to the insulating layer while still achieving strong bonding through the glass-containing Ag paste formulation
Solution Approach 2:
The glass-containing Ag paste acts as an intermediary material between the metal layer and heat sink. The glass component facilitates bonding at lower temperatures that do not damage the insulating layer, while the Ag component ensures good thermal and electrical conductivity. This intermediary material enables bonding without directly exposing the insulating layer to high temperatures
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 effectively reduces thermal load and warpage in the power module substrate and heat sink, improving reliability by ensuring strong bonding and minimizing thermal deterioration, while maintaining excellent insulation and thermal conductivity.
Implementation Method 1
an oxide film formed on the surface of the metal layer can be removed by the glass component
Implementation Method 2
the first base layer is composed of a sintered body of a glass-containing Ag paste
Implementation Method 3
a bonding layer composed of a sintered body of a bonding material including at least one of metal Ag particles and metal Ag oxide particles
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A power module substrate includes an insulating layer (11), a circuit layer (12) that is formed on a first surface of the insulating layer, and a metal layer (13) that is formed on a second surface of the insulating layer, in which a first base layer (20) is laminated on a surface of the metal layer on the opposite side of the surface to which the insulating layer is provided, and the first base layer has: a first glass layer that is formed at the interface with the metal layer; and a first Ag layer that is laminated on the first glass layer.