Semiconductor Device Solder Solidification Control
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Solution Overview
Problem
In semiconductor devices with embedded semiconductor elements and metal plates, the difference in thickness and solidifying points of soldered portions can cause metal plates to tilt due to uneven contraction, leading to insufficient solder thickness and potential interference, especially as size reduction and smaller electrode areas exacerbate this issue.
Innovation Solution
The semiconductor device design ensures that the total sum of thicknesses of soldered portions between metal plates is thinner than the thickness of the soldered portion between joints, allowing the thinner soldered portions to solidify before the thicker one, maintaining parallelism and preventing tilt by controlling the solidifying points of soldered portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If soldered portions of different thicknesses are used to bond metal plates and semiconductor elements, then the bonding structure can accommodate varying electrode areas, but the differential contraction during solidification causes metal plates to tilt
Solution Approach 1:
The patent applies parameter changes by varying the solidifying points of different soldered portions through material selection. Thinner soldered portions use high-solidifying-point materials while thicker portions use low-solidifying-point materials, ensuring sequential solidification that prevents tilt and maintains metal plate parallelism during cooling
Solution Approach 2:
The patent implements local quality by assigning different material properties to different soldered portions based on their thickness and location. Each soldered portion is selectively bonded with appropriate solder materials having different solidifying points, creating localized quality variations that collectively prevent overall structural tilt
2Productivity
If size reduction is implemented in semiconductor elements to improve integration density, then more elements can be packaged, but the bonding area difference between electrodes and joints decreases, making tilt more prominent
Solution Approach 1:
The patent uses parameter changes by adjusting the solidifying point parameter of solder materials based on soldered portion thickness. This ensures that even with reduced size and smaller bonding areas, the sequential solidification process maintains proper alignment and prevents tilt, preserving manufacturing precision despite miniaturization
3Strength
If thicker soldered portions are used to ensure sufficient bonding, then bonding strength is improved, but the solidification time increases and may cause tilt before thinner portions solidify
Solution Approach 1:
The patent resolves this contradiction by changing the solidifying point parameter of the solder material rather than uniformly increasing thickness. Thicker soldered portions use low-solidifying-point materials that solidify later, while thinner portions use high-solidifying-point materials that solidify first, maintaining both adequate bonding strength and structural parallelism through controlled sequential solidification
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 prevents tilt of metal plates, ensures sufficient solder thickness, and avoids interference by allowing the thinner soldered portions to solidify first, thereby maintaining parallelism and ensuring proper bonding without compromising post-bonding thickness.
Implementation Method 1
The soldered portions contract upon solidifying
Implementation Method 2
The soldered portions contract upon solidifying
Data Source
AI summary
A semiconductor device includes a first metal plate and a second metal plate which interpose a first semiconductor element therebetween, the first metal plate and the second metal plate being bonded to the first semiconductor element with first soldered portions; and includes a third metal plate and a fourth metal plate which interpose a second semiconductor element therebetween, the third metal plate and the fourth metal plate being bonded to the second semiconductor element with second soldered portions. A first joint provided at an edge of the first metal plate and a second joint provided at an edge of the fourth metal plate are bonded with a third soldered portion. A total sum of thicknesses of the first soldered portions is different from a thickness of the third soldered portion, a solidifying point of the thinner one is higher than a solidifying point of the thicker one.