Semiconductor Device Thermal Stress Reduction via Local Quality
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Solution Overview
Problem
The existing semiconductor device design generates high thermal stress at the circumferentially-outward end of the solder layer due to inefficient heat transfer from the semiconductor substrate, leading to potential damage and reduced pressure resistance.
Innovation Solution
The semiconductor device configuration includes a surface metallic layer and solder layer positioned on the insulating protective film, with the circumferentially-outward ends of these layers located more inwardly than the peripheral electrode, facilitating heat transfer through the insulating protective film with lower thermal conductivity, thus reducing thermal stress and maintaining electric potential distribution integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the surface metallic layer and solder layer are positioned to extend to the circumferentially-outward end of the peripheral electrode, then the heat transfer from the main electrode is improved, but the thermal stress at the circumferentially-outward end of the solder layer increases
Solution Approach 1:
The patent applies local quality by positioning the circumferentially-outward ends of the surface metallic layer and solder layer at different radial positions relative to the peripheral electrode. Specifically, the solder layer end is placed at a position more circumferentially inward than the peripheral electrode end, while the surface metallic layer extends to the peripheral electrode end. This creates a gradient in thermal conductivity and heat transfer capability across different radial positions, reducing thermal stress at the solder layer end while maintaining effective heat transfer through the surface metallic layer.
2Loss of energy
If the surface metallic layer extends onto the insulating protective film, then the heat transfer path is extended, but the electric potential distribution in the depletion layer is disturbed
Solution Approach 1:
The patent applies local quality by differentiating the radial extent of the surface metallic layer and solder layer relative to the peripheral electrode. The surface metallic layer extends to the peripheral electrode end to maintain heat transfer efficiency, while the solder layer is positioned more circumferentially inward to preserve electric potential distribution in the depletion layer. This localized differentiation allows each layer to fulfill its primary function without interfering with the other's performance.
3Stress or pressure
If the circumferentially-outward end of the solder layer is positioned at the peripheral electrode end, then the thermal conduction is maximized, but the pressure resistance of the semiconductor device decreases
Solution Approach 1:
The patent applies local quality by positioning the circumferentially-outward end of the solder layer at a location more circumferentially inward than the peripheral electrode end. This creates a localized region where thermal conduction is optimized without extending to the high-stress boundary at the peripheral electrode end. The surface metallic layer continues to extend to the peripheral electrode end to maintain overall thermal conduction efficiency, while the solder layer's retracted position protects against thermal stress concentration that would compromise pressure resistance.
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 configuration effectively suppresses thermal stress at the solder layer's circumferentially-outward end, protecting the main electrode and enhancing the pressure resistance of the semiconductor device by minimizing heat transfer and maintaining electric potential distribution.
Implementation Method 1
heat transfer through the insulating protective film with lower thermal conductivity
Implementation Method 2
both the main electrode and the surface metallic layer have a high thermal conductivity, heat is easily transferred from the main electrode via the surface metallic layer to the circumferentially-outward end of the solder layer
Data Source
AI summary
A semiconductor device includes: a semiconductor substrate; a main electrode; a peripheral electrode; an insulating protective film; a surface metallic layer; and a solder layer, wherein the semiconductor substrate includes: a first region of a first conductive-type in contact with the main electrode on a main contact surface; a second region of a first conductive-type in contact with the peripheral electrode on a peripheral contact surface; and a third region of a second conductive-type provided under the first region, under the second region, and circumferentially outward of the second region, and a circumferentially-outward end of the metallic layer and a circumferentially-outward end of the solder layer are located more circumferentially inward than the circumferentially-outward end of the peripheral electrode.