Semiconductor Device Tray With Heat-Resistant Sealing Resin
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Solution Overview
Problem
Existing power modules face challenges in maintaining structural integrity and insulation quality due to high loading on electrode roots during transfer molding, potential insulation breakdown, and thermal expansion issues with pail-shaped metal plates, leading to package size increases and degradation over time.
Innovation Solution
A semiconductor device with a concave tray housing a circuit part and sealing resin, where external electrodes are exposed and the resin has a higher heat-resistant temperature than solder, eliminating the need for excessive loading and ensuring insulation between electrodes and the metal tray, thus preventing structural damage and quality degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If transfer molding method is used to seal the circuit part, then the package size is reduced, but excessively-larger loads are applied to the root portions of the electrodes which may cause damages to the substrate and semiconductor elements
Solution Approach 1:
The patent applies preliminary action by pre-positioning the electrodes in recesses of the mold before sealing, and by designing the mold with electrode positioning structures that guide the electrodes into proper positions. This preliminary positioning prevents excessive loading on electrode roots during the sealing process, while still achieving compact package size through the transfer molding method.
2Ease of operation
If electrodes are bent or pressed against the die to expose them, then the electrodes are exposed outside, but gaps between the electrodes and sealing resin are induced which may cause insulation breakdown and moisture absorption
Solution Approach 1:
The patent introduces an intermediary substance (sealing resin) that fills the gaps between the electrodes and the exterior environment. The resin is specifically selected to provide both sealing and insulation properties, preventing moisture absorption and insulation breakdown while allowing electrode exposure for electrical connection.
Solution Approach 2:
The patent employs composite material structure by combining the sealing resin with insulation properties, creating a material that simultaneously provides gap filling, moisture barrier, and electrical insulation functions. This composite approach resolves the contradiction between electrode exposure and insulation quality.
3Device complexity
If a pail-shaped metal plate is used, then the structure is simplified, but thermal expansion coefficient difference causes exfoliation from sealing resin which degrades insulation property over time
Solution Approach 1:
The patent applies parameter changes by carefully selecting materials with thermal expansion coefficients that are matched or compatible. The sealing resin is chosen to have thermal expansion properties that match the metal plate, preventing exfoliation during thermal cycling while maintaining structural simplification.
4Strength
If soldering is used to connect metal plate to cooling device, then the connection is strong, but softening and deformations of the sealing resin are induced
Solution Approach 1:
The patent extracts the high-temperature soldering process from the sealing resin environment by providing thermal isolation. The metal plate is designed with thermal barrier structures or the sealing resin is positioned away from the soldering zone, allowing strong soldering connections without exposing the resin to temperatures that cause softening or deformation.
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
The solution prevents damage to semiconductor elements and substrates, maintains insulation integrity, and reduces package size by ensuring the sealing resin's heat-resistant properties withstand thermal stresses, thereby enhancing the reliability and longevity of the semiconductor device.
Implementation Method 1
a sealing resin configured to be injected in the accommodating part and seal, in potting, the circuit part housed in the accommodating part
Implementation Method 2
the sealing resin having a heat resistant temperature which is higher than the melting point of a solder for bonding the tray to a cooling device
Data Source
AI summary
The present invention has a tray corresponding to a heat sink, a circuit part is accommodated in an accommodating part of the tray, and the circuit part is potting-sealed with a sealing resin such that external electrodes are exposed. The sealing resin covers and seals a top part of the tray.