Locally Delimited Sintering for Power Semiconductor Modules
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Solution Overview
Problem
Existing methods for connecting power semiconductor modules require multiple materials and complex processes, leading to increased workload and costs, and have a narrow process window for achieving high-temperature and temperature-resistant connections.
Innovation Solution
A method involving locally delimited sintering is used to attach a metal body or semiconductor to a substrate by applying unsintered sinter material and using pressure and temperature with a stamp to compact and fix the components, allowing for a complete-area sintering process that maintains high thermal and electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple connection materials (adhesive and sinter paste) are used for attaching components, then the connection reliability is improved, but the device complexity and manufacturing workload increase
Solution Approach 1:
The patent combines adhesive and sinter paste into a single dual-functional sinter paste material that provides both attaching (adhesion) and sintering functions. This eliminates the need for separate connection materials and simplifies the process steps while maintaining connection reliability.
Solution Approach 2:
The sinter paste is designed to perform multiple functions: it acts as both an adhesive for initial attaching and a sintering material for creating high-temperature resistant connections. This multi-functionality reduces the number of materials and process steps required.
2Strength
If complete-area precompaction is applied to attach metal bodies, then the attaching strength is improved, but the process window becomes very narrow and sinterability is compromised
Solution Approach 1:
The patent applies precompaction only to locally delimited areas where metal bodies need to be attached, rather than complete-area precompaction. This localized approach provides sufficient attaching strength while preserving the sinterability of the remaining sinter paste areas.
Solution Approach 2:
Instead of applying complete-area precompaction, the patent uses partial precompaction only where necessary for attaching. This partial action achieves the required attaching strength without over-compacting the sinter paste, thereby maintaining an adequate process window for subsequent sintering.
3Reliability
If different connection materials are used for attaching and sintering, then the connection properties are improved, but the manufacturing cost and workload increase
Solution Approach 1:
The patent merges the functions of adhesive and sinter paste into a single material system. The sinter paste performs both attaching and sintering functions, eliminating the need for separate application and processing of multiple connection materials, thereby reducing manufacturing workload and costs.
Solution Approach 2:
The sinter paste is formulated to provide both adhesion properties for attaching and sintering properties for creating high-temperature resistant connections. This universal material eliminates the need for multiple specialized materials and simplifies the manufacturing process.
4Loss of energy
If the semiconductor thickness is reduced to decrease electrical losses, then the electrical efficiency is improved, but the mechanical strength and thermal management become compromised
Solution Approach 1:
The patent changes the bonding mechanism from mechanical interlocking (which requires thick semiconductors) to sintering-based cohesive connection. This parameter change in the bonding process enables thin semiconductor structures to achieve sufficient mechanical strength and thermal management through the sintered connection's high bonding strength and thermal conductivity.
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 method simplifies the attachment process, reduces material complexity, and ensures a robust connection with high mechanical strength and thermal conductivity, while avoiding the risks associated with previous methods like 'Pick & Fix', by achieving a cohesive connection with minimal precompaction and sintering outside the localized area.
Implementation Method 1
Method for cohesively connecting a first component of a power semiconductor module to a second component of a power semiconductor module by sintering
Implementation Method 2
attaching the second component to the first component by applying pressure and/or temperature on a locally delimited partial area within the predetermined bonding surface
Data Source
AI summary
A method for cohesively connecting a first component of a power semiconductor module to a second component of a power semiconductor module by sintering, the method comprising the steps of: applying a layer of unsintered sinter material to a predetermined bonding surface of the first component, arranging the second component on the surface layer of unsintered sinter material, attaching the second component to the first component by applying pressure and/or temperature on a locally delimited partial area within the predetermined bonding surface, processing the first and/or second component and/or other components of the power semiconductor module, and complete-area sintering of the sinter material.