Large-Area Semiconductor Encapsulation Resin Composition
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Solution Overview
Problem
Large-area semiconductor wafers and substrates face challenges with encapsulation due to contraction stress and warpage issues, leading to filling failures and flow marks, which hinder mass production and affect the reliability of semiconductor devices.
Innovation Solution
A method involving compression molding with a curable epoxy resin composition containing an epoxy resin, a curing agent, a pre-gelatinizing agent, and a filler, under specific temperature and pressure conditions, to effectively encapsulate large-area semiconductor elements, reducing warpage and preventing filling failures and flow marks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large-area silicon wafer or substrate is encapsulated using conventional epoxy resin, then encapsulation is achieved, but significant contraction stress occurs after encapsulation causing semiconductor elements to peel off from the substrate
Solution Approach 1:
The patent changes the chemical composition parameters of the resin by incorporating a rubber component (polyisoprene or polybutadiene) at 5-50 mass% and a thermoplastic resin at 5-50 mass% into the epoxy resin system. This compositional parameter change reduces the contraction stress during curing while maintaining encapsulation reliability, preventing semiconductor elements from peeling off the substrate.
Solution Approach 2:
The patent creates a composite resin material combining epoxy resin with rubber components and thermoplastic resins. This composite structure integrates the adhesive properties of epoxy with the stress-absorbing characteristics of rubber and the flow-enhancing properties of thermoplastic resins, achieving both reliable encapsulation and reduced contraction stress on large-area substrates.
2Shape
If glass substrates and metal substrates are used for large-diameter wafers, then warpage prevention is attempted, but filling failures and flow marks occur on the outer circumferential portion
Solution Approach 1:
The patent adjusts the resin composition parameters by adding thermoplastic resin (5-50 mass%) which enhances flowability, and rubber component (5-50 mass%) which improves filling characteristics. These parameter changes enable complete filling of large-area substrates without creating flow marks or filling failures, while maintaining proper shape control.
Solution Approach 2:
The composite resin system combines epoxy resin, rubber components, and thermoplastic resins to achieve a balanced material properties profile. The thermoplastic resin provides flowability for complete filling, the rubber component prevents flow marks through stress absorption, and the epoxy provides adhesion, collectively solving both warpage control and filling uniformity issues.
3Stress or pressure
If filler is added to reduce contraction stress by lowering resin elasticity, then stress reduction is achieved, but flowability deteriorates significantly
Solution Approach 1:
The patent uses a composite material system where rubber components (5-50 mass%) and thermoplastic resins (5-50 mass%) are combined with epoxy resin and filler. The rubber component provides stress absorption to reduce contraction stress, while the thermoplastic resin maintains flowability by providing a lubricating effect during filling, preventing the trade-off between stress reduction and flowability deterioration.
Solution Approach 2:
The patent optimizes the filler content parameter to 70-90 mass% while simultaneously adjusting the rubber and thermoplastic resin content to maintain proper flowability. This coordinated parameter change allows the resin to flow completely into the mold cavity while the rubber component absorbs contraction stress, achieving both good fillability and stress reduction.
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 method allows for successful encapsulation of large-area semiconductor elements with reduced warpage and improved heat resistance, enhancing the reliability and consistency of the semiconductor devices.
Implementation Method 1
using a curable epoxy resin composition comprising (A) an epoxy resin; (B) a curing agent
Implementation Method 2
a significant warpage will occur due to a difference in thermal expansion coefficient between silicon and the heat-curable resin
Implementation Method 3
encapsulation step of collectively encapsulating a semiconductor element-mounted surface
Implementation Method 4
using a heat-curable resin to encapsulate the semiconductor elements
Data Source
AI summary
Provided is an encapsulation method not causing molding failures such as filling failures and flow marks when collectively encapsulating a large-area silicon wafer or substrate with a resin composition. Specifically, provided is a method for encapsulating a semiconductor element-mounted base material, using a curable epoxy resin composition containing: an epoxy resin (A), a curing agent (B), a pre-gelatinizing agent (C) and a filler (D). The semiconductor element-mounted base material is collectively encapsulated under conditions of (a) molding method: compression molding, (b) molding temperature: 100 to 175° C., (c) molding period: 2 to 20 min and (d) molding pressure: 50 to 350 kN.