Diffusion Solder Bond for Multi-Chip Electronic Component Assembly
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Solution Overview
Problem
The electrical performance of multi-chip electronic components is limited by the lateral size of the package due to the spreading of soft solder deposits, which reduces the available area for semiconductor components and can cause misalignment and incorrect wire bonding, especially when using multi-step die attach methods.
Innovation Solution
The use of a diffusion solder bond between semiconductor components and a die pad, which provides a mechanical and electrical connection with higher melting point intermetallic phases, allowing for a thinner bond that matches the semiconductor component's area, enabling closer packing and improved thermal dissipation without the issues of soft solder spreading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If soft solder deposit is used to attach semiconductor components, then mechanical connection is achieved, but solder spreads into adjacent regions reducing available area for components
Solution Approach 1:
The patent changes the physical and chemical parameters of the bonding process by using diffusion bonding at elevated temperatures (e.g., 400-800°C) instead of soft soldering at lower temperatures. This parameter change transforms the bonding mechanism from plastic deformation and solidification to atomic diffusion and intermetallic compound formation, eliminating solder spread while maintaining strong mechanical attachment
Solution Approach 2:
The patent replaces the mechanical soft solder bonding system with a thermal diffusion bonding system. Instead of using a eutectic solder alloy that melts and solidifies, the invention uses direct diffusion bonding where atoms interdiffuse across the interface between the semiconductor component and die pad, creating a metallurgical bond without any solder material to spread
2Adaptability or versatility
If multi-step die attach method is used, then subsequent components can be attached, but previously attached components may move or sink into solder deposit
Solution Approach 1:
The patent changes the thermal parameters of the bonding process by using elevated temperature diffusion bonding (400-800°C) that creates strong intermetallic phases. This parameter change ensures that once bonding occurs, the bond is thermally stable and mechanically rigid, preventing any component movement or sinking during subsequent assembly steps
Solution Approach 2:
The patent inverts the traditional approach by performing diffusion bonding directly without intermediate soft soldering steps. This inversion eliminates the problematic intermediate state where soft solder is present and can cause component movement, instead creating a stable metallurgical bond from the outset that prevents subsequent displacement
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 allows for increased semiconductor component area within a defined package footprint, enhancing electrical performance and reliability by avoiding the problems associated with soft solder bonding, such as component misalignment and thermal dissipation limitations.
Implementation Method 1
lower side of the at least two semiconductor components is attached to the die pad by a diffusion solder bond
Data Source
AI summary
An electronic component and method for its assembly is disclosed. In one embodiment, the electronic component comprises at least two semiconductor components and a circuit carrier comprising a die pad and a rewiring structure. At least one semiconductor component is a vertical semiconductor power switch having an upper surface comprising at least one electrode and a lower surface comprising at least one electrode. The lower side of the at least two semiconductor components is attached to the die pad by a diffusion solder bond.