Semiconductor Apparatus Laser Welding Heat Damage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor apparatuses using laser welding for bonding conductor plates to heat spreaders can cause heat damage to semiconductor elements due to localized heating, which may lead to inadequate bonding and continuity issues.
Innovation Solution
The semiconductor apparatus employs laser welding of a conductor plate to a metallic plate at a location other than directly above the semiconductor elements, with the molten area positioned between adjacent semiconductor elements to dissipate heat effectively, reducing heat damage and ensuring electrical continuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If laser welding is used to bond conductor plate to heat spreader, then bonding strength and electrical continuity are improved, but heat damage to semiconductor elements occurs due to localized heating
Solution Approach 1:
The patent applies local quality by making the heat spreader thicker specifically at the bonding area where laser welding occurs. This localized structural modification allows the bonding region to withstand high laser energy without transmitting excessive heat to the semiconductor elements, while other areas maintain their original design for optimal thermal management.
Solution Approach 2:
The patent implements beforehand cushioning by pre-designing the heat spreader with increased thickness at the bonding location before laser welding occurs. This proactive structural preparation absorbs and dissipates the localized heat generated during laser welding, preventing heat damage to the semiconductor elements before it can occur.
2Reliability
If conductor plate is bonded directly above semiconductor elements, then electrical connectivity is optimized, but heat damage occurs during laser welding
Solution Approach 1:
The patent applies local quality by making the heat spreader thicker specifically at the bonding area where laser welding occurs. This localized structural modification allows the bonding region to withstand high laser energy without transmitting excessive heat to the semiconductor elements, while other areas maintain their original design for optimal thermal management.
Solution Approach 2:
The patent uses the heat spreader as an intermediary structure between the laser welding process and the semiconductor elements. By increasing the heat spreader's thickness at the bonding location, it acts as a thermal buffer that mediates the heat transfer, allowing electrical connectivity to be established while protecting the semiconductor elements from harmful heat exposure.
3Object-affected harmful factors
If aluminum wires are used for electrical connection, then heat damage during bonding is minimized, but heat dissipation performance is insufficient compared to conductor plates
Solution Approach 1:
The patent applies parameter changes by transitioning from using aluminum wires to using a conductor plate with larger surface area and optimized thickness distribution. This parameter change in the electrical connection structure enables both improved heat dissipation performance and protection against heat damage through the strategically thickened bonding area.
Solution Approach 2:
The patent employs composite material strategy by combining the conductor plate made of high-conductivity material with a strategically designed thickness profile. The structure integrates regions of varying thickness to simultaneously achieve excellent electrical conductivity, efficient heat dissipation, and protection during laser welding processes.
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 approach effectively reduces heat damage to semiconductor elements during laser welding while maintaining electrical connectivity, ensuring reliable operation and improved bonding integrity.
Implementation Method 1
bonding of the conductor plate is carried out using an ultrasonic bonding method... if bonding of a conductor plate in place of the aluminum wires 208, 209, and 213 illustrated in FIG. 8 is carried out by laser welding. The locally generated heat is transmitted to a semiconductor element such as the IGBT element 214 through the heat spreader 212
Implementation Method 2
the bonding interface between the conductor plate and the heat spreader 212 is locally heated by laser irradiation
Implementation Method 3
the molten area positioned between adjacent semiconductor elements to dissipate heat effectively, reducing heat damage
Data Source
AI summary
A semiconductor apparatus equipped with at least one semiconductor element includes a metallic plate bonded to an upper surface of the semiconductor element and a conductor plate, bonded to the metallic plate and serving as an electric current path of the semiconductor apparatus. The conductor plate and the metallic plate are bonded to each other by laser welding at a part other than a part directly above the semiconductor element. As a result, heat damage caused by laser welding can be reduced.