Silicone Resin Semiconductor Encapsulation for Thermal Stability
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Solution Overview
Problem
Conventional encapsulation methods for photodetecting semiconductor devices using epoxy resins face issues with discoloration at high temperatures, surface tackiness, and crack generation, which affect reliability and durability, especially during thermal cycles.
Innovation Solution
A silicone resin composition that cures into a hard, transparent article with improved flexibility and reduced surface tackiness, using a polyorganosiloxane and polyorganohydrogen siloxane with specific resin structures and a platinum group catalyst, allowing for conventional molding techniques like transfer and compression molding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If epoxy resin is used for encapsulation, then transparency is maintained, but discoloration occurs at high temperature
Solution Approach 1:
The patent changes the chemical composition parameters of the encapsulation material from epoxy resin to a specific silicone resin system containing polyorganosiloxane and polyorganohydrogen siloxane in a controlled molar ratio (0.1 to 4.0), which fundamentally alters the thermal stability properties while maintaining transparency
Solution Approach 2:
The invention uses a composite silicone resin system combining polyorganosiloxane and polyorganohydrogen siloxane with a platinum group metal catalyst, creating a material that exhibits both high transparency and exceptional resistance to discoloration at elevated temperatures during solder reflow processes
2Reliability
If silicone rubber composition is used for encapsulation, then heat and light resistance is improved, but surface tackiness increases causing dust deposition
Solution Approach 1:
The patent precisely controls the molar ratio of hydrogen atoms bonded to silicon in polyorganohydrogen siloxane to vinyl or allyl groups in polyorganosiloxane within the range of 0.1 to 4.0, which optimizes the crosslinking density and surface properties to eliminate tackiness while preserving heat and light resistance
Solution Approach 2:
The invention creates different properties at different locations: the bulk material maintains high heat and light resistance through the silicone resin composition, while the surface becomes non-tacky through controlled crosslinking density achieved by the specific molar ratio of reactive groups
3Object-generated harmful factors
If silicone varnish is used for encapsulation, then surface tackiness is reduced, but crack generation occurs
Solution Approach 1:
The patent creates a composite silicone resin system combining polyorganosiloxane and polyorganohydrogen siloxane with a platinum group metal catalyst, where the controlled molar ratio (0.1 to 4.0) of reactive groups enables simultaneous achievement of non-tacky surface and high crack resistance through optimized crosslinking density
Solution Approach 2:
By adjusting the molar ratio of hydrogen atoms to vinyl/allyl groups within 0.1 to 4.0, the invention optimizes the crosslinking density parameter to achieve a balance between surface properties (non-tacky) and mechanical properties (crack resistance), preventing the brittleness observed in silicone varnish
4Object-generated harmful factors
If hard resin is used to improve strength, then surface tackiness is reduced, but impact strength and crack resistance become insufficient
Solution Approach 1:
The patent optimizes the crosslinking density parameter by controlling the molar ratio of reactive groups (0.1 to 4.0) in the silicone resin composition, achieving a balanced network structure that provides both hard surface characteristics (non-tacky) and sufficient toughness (impact strength and crack 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
The silicone resin composition provides a reliable encapsulation with high hardness and flexibility, reducing surface tackiness and crack generation, enabling semiconductor devices to withstand thermal cycles and maintain performance in applications where conventional packaging is challenging.
Implementation Method 1
a cured silicone resin composition which has low stress properties and transparency... using a polyorganosiloxane and polyorganohydrogen siloxane with specific resin structures and a platinum group catalyst
Implementation Method 2
a silicone rubber composition which cures by addition reaction can be improved to exhibit a higher strength after curing
Data Source
AI summary
A semiconductor device which is not a light emitting semiconductor device is provided. This device is encapsulated with a silicone resin composition which is solid at room temperature and liquid at molding temperature, and which cures into a transparent article having a hardness measured by Type D durometer according to JIS K 6253 of at least 30 and an elongation in a tensile test of at least 5%.