Interlocking Copper Bond Structure for Reliable Solder-Free Connections
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for forming electrical connections, such as soldering, face limitations due to solder's low melting point and atomic migration issues, while direct metal-to-metal bonds are costly and time-consuming to produce on a large scale.
Innovation Solution
The method involves forming interlocking metal-to-metal bonds using substrates with specifically shaped contact structures, such as dome-shaped and dish-shaped copper contacts, which are pressed together under high pressure and heat to enhance bonding, potentially reducing the need for solder and simplifying the assembly process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If soldering is used to form electrical connections, then ease of manufacture is improved, but reliability deteriorates due to low melting point and atomic migration
Solution Approach 1:
The invention changes the bonding parameters from low-temperature soldering to high-temperature direct metal-to-metal bonding. By forming copper-to-copper bonds at elevated temperatures (above the melting point of solder), the patent eliminates solder entirely, thereby removing the reliability issues associated with solder's low melting point and atomic migration while maintaining ease of manufacture through a modified but still practical process
2Reliability
If direct metal-to-metal bonds are formed, then reliability is improved by eliminating solder, but productivity deteriorates due to high temperatures, high pressures, and long dwell times
Solution Approach 1:
The invention applies preliminary actions to prepare the metal surfaces before bonding. By pre-forming the copper contacts with specific geometries (such as domed or planar shapes) and ensuring proper surface cleanliness and oxidation control prior to bonding, the patent reduces the actual bonding time and pressure requirements, thereby improving productivity while maintaining reliable direct metal-to-metal bonds
Solution Approach 2:
The invention employs curved surface geometries (domed copper contacts) instead of flat surfaces. The spherical or domed shape increases the contact area and distributes the bonding pressure more evenly during the bonding process, reducing peak pressure requirements and dwell time, thus improving productivity while achieving reliable metal-to-metal bonds
3Reliability
If direct metal-to-metal bonds are formed, then reliability is improved, but device complexity increases due to process complications
Solution Approach 1:
The invention merges multiple process steps into a single integrated bonding operation. By combining surface preparation, heating, and bonding into one continuous process step, and by using the same copper material for both the contact and the bond interface, the patent simplifies the overall device structure and manufacturing process while maintaining reliable direct metal-to-metal bonds
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 enables effective metal-to-metal bonding with potentially lower temperature and dwell time requirements, improving the reliability and efficiency of electrical connections while avoiding the limitations of traditional soldering methods.
Implementation Method 1
pressing the mated dome-shaped end and dish-shaped end together to form a copper-to-copper bond
Implementation Method 2
pressing the mated dome-shaped end and dish-shaped end together to form a copper-to-copper bond
Data Source
AI summary
A structure and method for performing metal-to-metal bonding in an electrical device. For example and without limitation, various aspects of this disclosure provide a structure and method that utilize an interlocking structure configured to enhance metal-to-metal bonding.