Silver-Coated Semiconductor Bonding for Thermal Dissipation
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Solution Overview
Problem
Conventional die-attach methods for semiconductor elements, such as resin bonding and eutectic bonding, face issues with thermal degradation and poor thermal conductivity, leading to reliability concerns and heat dissipation problems in light emitting diodes and laser diodes.
Innovation Solution
A method involving the direct bonding of silver-coated surfaces on a semiconductor element and a base using an organic solvent or water, with heat application between 200 to 260°C to achieve strong and reliable bonding, eliminating the need for intermediate materials and enhancing thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If resin bonding is used for mounting semiconductor elements, then bonding can be accomplished at low temperatures of 150 to 200°C, but the resin deteriorates with time due to heat generation, resulting in discoloration and deterioration of bonding strength
Solution Approach 1:
The patent removes the organic resin component from the bonding interface entirely, extracting the harmful element that causes deterioration. Instead of using resin-based adhesives, the invention employs a metal plate with metal adhesive layers that directly bond to the semiconductor element and substrate, eliminating the time-dependent degradation issues inherent in organic materials while maintaining low-temperature bonding capability.
Solution Approach 2:
The invention changes the material parameter from organic resin to inorganic metal adhesive layers. This fundamental material substitution transforms the bonding system from one susceptible to thermal degradation and discoloration to a stable, heat-resistant configuration that maintains bonding strength over time while operating at low temperatures.
2Ease of manufacture
If resin bonding is used, then curing can be readily accomplished at low temperatures, but thermal degradation of the thermosetting resin and melting of the thermoplastic resin can occur, causing separation due to thermal shock
Solution Approach 1:
The patent extracts the vulnerable resin component from the bonding system, replacing it with metal adhesive layers that are inherently resistant to thermal shock. This eliminates the problem of resin melting or degradation during subsequent high-temperature soldering processes, while the metal-based bonding maintains ease of manufacture through straightforward metallurgical bonding processes.
3Ease of manufacture
If resin bonding or silver paste bonding is used, then bonding can be achieved, but poor thermal conductivity and insufficient heat releasability cause light emitting diodes to become unilluminable
Solution Approach 1:
The invention fundamentally changes the thermal conductivity parameter by substituting organic resin or silver paste with a metal plate structure featuring metal adhesive layers. This material transformation creates a high-thermal-conductivity pathway that efficiently transfers heat from the semiconductor element through the bonding interface to the substrate, preventing heat accumulation while maintaining manufacturing simplicity.
Solution Approach 2:
The patent employs a composite structure consisting of a metal plate with specific metal adhesive layers (such as Cu-Sn or Ag-Sn systems) that combine the high thermal conductivity of metals with optimized bonding characteristics. This composite approach achieves superior heat dissipation while maintaining ease of manufacture through controlled metallurgical bonding processes.
4Reliability
If eutectic bonding is used, then high reliability and good heat releasability are achieved, but heating to 300°C or greater is required, which is not applicable to widely used resin packages
Solution Approach 1:
The invention changes the bonding temperature parameter from high temperature (300°C or greater required for eutectic bonding) to low temperature (150-200°C sufficient for metal adhesive bonding). This is achieved by using metal adhesive layers with appropriate melting points and bonding characteristics that enable reliable metallurgical bonding at lower temperatures, making the process compatible with standard resin packages that cannot withstand high heat.
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 provides a reliable, cost-effective semiconductor device with improved heat dissipation and high emission efficiency, avoiding thermal deterioration and discoloration issues, while simplifying the production process.
Implementation Method 1
bonding the semiconductor element and the base by applying heat having a temperature of 200 to 260° C. for 1 to 2 hours to the semiconductor element and the base
Implementation Method 2
enhancing thermal conductivity
Data Source
AI summary
An object of the invention is to provide a method for producing a conductive member having low electrical resistance, and the conductive member is obtained using a low-cost stable conductive material composition that does not contain an adhesive. In the semiconductor device, silver arranged on a semiconductor element and silver arranged on a base are bonded. No void is present or a small void, if any, is present at an interface between the semiconductor element and the silver arranged on the semiconductor element, no void is present or a small void, if any, is present at an interface between the base and the silver arranged on the base, and one or more silver abnormal growth grains and one or more voids are present in a bonded interface between the silver arranged on the semiconductor element and the silver arranged on the base.