Encapsulating Resin Composition for Power Device HTRB Resistance
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Solution Overview
Problem
Current encapsulating resin compositions for power devices do not adequately enhance high temperature reverse bias (HTRB) resistance, which is crucial for high withstand voltage power devices used in electric vehicles and eco-friendly home appliances.
Innovation Solution
An encapsulating resin composition comprising an epoxy resin, surface-treated silica inorganic filler, and a curing agent, molded and after-cured under specific conditions to achieve a half width of the current-time curve of 800 seconds or less when measured by the thermally stimulated depolarization current method, thereby improving HTRB resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional encapsulating resin compositions are used, then the power device can be manufactured with standard materials, but the HTRB resistance is insufficient for high withstand voltage applications
Solution Approach 1:
The patent modifies the chemical composition parameters of the encapsulating resin by incorporating specific inorganic fillers (silica, alumina, magnesia) with controlled particle sizes and surface treatments, along with precise ratios of epoxy resins and curing agents, to achieve both high HTRB resistance and maintainable moldability
Solution Approach 2:
The patent creates a composite encapsulating resin composition combining organic epoxy resin matrix with inorganic fillers (silica, alumina, magnesia) and surface treatment agents, where the synergistic interaction between components achieves enhanced HTRB resistance while preserving manufacturing properties
2Reliability
If the encapsulating resin composition is optimized for HTRB resistance, then the power device achieves excellent high temperature reverse bias performance, but the manufacturing process becomes more complex
Solution Approach 1:
The patent applies different surface treatments to different inorganic fillers based on their specific properties and functions - silica particles receive hydrophobic surface treatment for moisture resistance, while alumina and magnesia are used in specific combinations for their respective electrical and thermal properties, optimizing each component's contribution to HTRB resistance
Solution Approach 2:
The patent performs surface treatment on inorganic fillers before incorporating them into the epoxy resin matrix, pre-modifying their surfaces with hydrophobic agents or coupling agents to ensure proper dispersion and bonding, thereby simplifying the final mixing and molding processes
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 encapsulating resin composition effectively enhances the HTRB resistance of power devices, ensuring reliable performance under high temperature and voltage conditions.
Implementation Method 1
a half width of a current-time curve obtained by measuring the test piece with a thermally stimulated depolarization current method
Data Source
Figure 1~2
AI summary
Provided is an encapsulating resin composition for a power device including an epoxy resin, an inorganic filler, a curing agent, and a curing accelerator. This composition is molded under a condition of 175°C for 2 minutes and then subjected to after-curing under a condition of 175°C for 4 hours to obtain a test piece having a diameter of 100 mm and a thickness of 2 mm, and a half width of a current-time curve obtained by measuring the test piece with a thermally stimulated depolarization current method according to an order of (i) to (v) below is equal to or less than 800 seconds, (i) increase a temperature of the test piece to 150°C at a rate of 5°C/min without applying a voltage, (ii) applying a constant voltage of 500 V for 30 minutes while maintaining the temperature of the test piece at 150°C, (iii) lower the temperature of the test piece to 45°C at a rate of 5°C/min while applying the constant voltage of 500 V, (iv) stop applying the voltage while maintaining the temperature of the test piece at 45°C and leave the test piece to stand for 5 minutes, and (v) increase the temperature of the test piece at a rate of 3.5°C/min without applying a voltage to the test piece, and measure a value of a current flowing during the increase in the temperature to obtain a current-time curve.