Semiconductor Conductor Layout for Thermal Stress Relief
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Solution Overview
Problem
Conventional semiconductor devices with switching elements face issues of cracking in the bonding layer and detachment of wires due to thermal stress, particularly when using materials with large differences in linear expansion coefficients.
Innovation Solution
The semiconductor device incorporates insulating support members with conductive layers and detection/gate conductors having ends with lower linear expansion coefficients, utilizing alloy layers and metal pieces to mitigate thermal stress, and includes detection and gate wiring layers to enhance electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a metal piece made of aluminum is used to promote heat dissipation and reduce ON-resistance, then heat dissipation performance is improved, but thermal stress and cracking in the bonding layer occur due to large coefficient of linear expansion
Solution Approach 1:
The patent employs a composite conductor structure consisting of a first conductor (aluminum or aluminum alloy) and a second conductor (copper or copper alloy) with different coefficients of linear expansion. The first conductor provides excellent heat dissipation performance, while the second conductor with smaller expansion coefficient reduces thermal stress and prevents bonding layer cracking. This composite material approach resolves the contradiction between heat dissipation performance and bonding layer reliability.
2Reliability
If copper is used as the metal piece material to reduce coefficient of linear expansion and prevent bonding layer cracking, then bonding layer reliability is improved, but thermal stress concentrates on wires causing detachment from the semiconductor element
Solution Approach 1:
The conductor is divided into two separate segments: a first conductor (aluminum-based) and a second conductor (copper-based), which are electrically connected but structurally distinct. This segmentation allows each material to perform its optimal function—the aluminum portion handles high current and heat dissipation, while the copper portion provides thermal stress management—thereby preventing wire detachment caused by stress concentration.
Solution Approach 2:
The patent introduces an intermediary conductor structure that mediates between the semiconductor element and the external circuit. The multi-conductor configuration acts as an intermediary system that distributes thermal stress away from the wire bonds, preventing detachment while maintaining electrical connectivity.
3Device complexity
If wires are directly connected to the semiconductor element, then electrical connection is simple, but thermal stress causes wire detachment
Solution Approach 1:
The connection structure uses a composite conductor system with multiple materials (aluminum and copper conductors) that have complementary properties. This composite structure enhances connection stability by distributing thermal stress across different materials with different expansion coefficients, preventing wire detachment while maintaining relatively simple electrical connectivity.
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 design reduces cracking and wire detachment, enhancing the reliability and durability of the semiconductor device by aligning thermal expansion coefficients and improving electrical connectivity.
Implementation Method 1
At least one of the first detection conductor and the first gate conductor has an end connected to the first semiconductor element, where the end has a coefficient of linear expansion smaller than a coefficient of linear expansion of the first conductive layer
Data Source
AI summary
A semiconductor device includes an insulating support member, a first and a second conductive layer, a first semiconductor element, a first lead, a first detection conductor and a first gate conductor. The first and second conductive layers are disposed on a front surface of the insulating support member. The first semiconductor includes a first and a second electrode on the same side, and a third electrode disposed on the other side and electrically connected to the first conductive layer. The first lead is connected to the first and second conductive layer. The first detection conductor is connected to the first electrode. The first gate conductor is connected to the second electrode. At least one of the first detection conductor and the first gate conductor has an end connected to the first semiconductor element. The end has a coefficient of linear expansion smaller than that of the first conductive layer.