Interconnection Structure Using Diffusion Solder for Reliable Mounting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic components can be damaged during the mounting process on a printed circuit board due to the remelting of soft solder connections, leading to unreliable or failed connections.
Innovation Solution
The use of electrically conductive bumps with a metal body free of solder and an outermost layer of diffusion solder, which forms a diffusion solder bond with a higher melting point, providing a stable mechanical and electrical connection that does not remelt during subsequent heat treatments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If soft solder connections are used for mounting electronic components, then ease of manufacture is improved, but reliability deteriorates due to remelting during subsequent heat treatments
Solution Approach 1:
The patent changes the melting point parameter of the solder material by using diffusion solder (such as copper-tin or nickel-tin diffusion bonds) instead of conventional soft solder. This parameter change ensures the solder connection remains stable during subsequent reflow processes, resolving the reliability issue while maintaining manufacturing ease through automated mounting processes.
Solution Approach 2:
The patent employs composite material structures where diffusion solder forms intermetallic compound layers (such as Cu6Sn5, Cu3Sn, or Ni3Sn4) between the solder and substrate. This composite structure provides both mechanical bonding strength and resistance to remelting, thereby improving connection reliability while maintaining ease of manufacture through standardized mounting procedures.
2Ease of manufacture
If conventional soldering processes are used, then ease of manufacture is improved, but harmful factors increase due to damage to electronic components during mounting
Solution Approach 1:
By changing the thermal parameter (melting point) of the solder material to a higher value through diffusion soldering, the patent prevents remelting of existing connections during subsequent heat treatments. This eliminates the harmful effect of thermal damage to electronic components while maintaining ease of assembly through automated processes.
3Adaptability or versatility
If multiple mounting processes are performed, then adaptability is improved, but reliability deteriorates due to cumulative thermal damage from remelting
Solution Approach 1:
The patent changes the thermal stability parameter of the solder joint by using diffusion solder with higher melting point, enabling multiple mounting and heat treatment processes to be performed without cumulative thermal damage. This supports adaptability for multi-chip modules while maintaining connection stability and reliability.
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 solution prevents the remelting of solder connections, ensures reliable attachment of semiconductor components, allows for multi-chip modules, and reduces the height and area of interconnection structures, enhancing the performance and reliability of electronic components.
Implementation Method 1
an outermost layer of diffusion solder is positioned on at least regions of the metal body
Data Source
AI summary
An interconnection structure includes an electrically conductive bump, wherein the electrically conductive bump has a metal body having a distal end. The metal body is free of solder. An outermost layer of diffusion solder is positioned on at least regions of the metal body of the electrically conductive bump.