Silicone Resin Composition for Wafer Encapsulation
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Solution Overview
Problem
Current techniques for encapsulating semiconductor wafers face challenges such as wire deformation, short filling, and warpage, especially with the transition to larger diameter and thinner wafers, requiring a material that can provide effective adhesion, minimal warpage, and reliable protection during the molding process.
Innovation Solution
A silicone resin composition combining a first silicone resin with 10-40% silicone content and a second silicone resin with 50-80% content, along with an epoxy resin curing agent and a filler like silica, is used to form a resin film that can encapsulate wafers efficiently, offering improved adhesion, low warpage, and enhanced protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transfer molding technique is used to encapsulate semiconductor wafers, then encapsulation can be achieved, but wire deformation occurs and short filling is more likely as encapsulation area becomes larger
Solution Approach 1:
The patent changes the physical state parameter of the molding material from solid (conventional transfer molding) to liquid silicone resin composition. This parameter change allows the material to flow and fill narrow gaps effectively without causing wire deformation, while also enabling complete filling of large encapsulation areas without short filling issues.
Solution Approach 2:
The patent uses a composite material system consisting of liquid silicone resin combined with epoxy resin and filler particles. This composite formulation provides both the flowability needed to avoid wire deformation and the structural properties required for complete filling and strong adhesion to the wafer surface.
2Ease of manufacture
If compression molding technique is used, then molding can be performed, but it is difficult to precisely control the molding range at the end portion of the wafer
Solution Approach 1:
The patent replaces the mechanical compression molding system with a chemical curing system. The liquid silicone resin composition is applied to the wafer surface and then cured in place, eliminating the need for mechanical pressure control and enabling precise molding range control at the wafer edges through chemical reaction rather than mechanical force.
Solution Approach 2:
The patent changes the molding mechanism from mechanical compression to chemical curing. This parameter change allows the molding range to be precisely controlled by the application area of the liquid resin rather than by mechanical pressure distribution, solving the problem of imprecise control at wafer end portions.
3Productivity
If conventional molding materials are used for large diameter and thin wafers, then molding can be performed, but warpage becomes significant and wafer protection is insufficient
Solution Approach 1:
The patent employs a composite material system of liquid silicone resin with epoxy resin and filler particles that provides superior adhesion to thin wafer surfaces. This composite formulation maintains wafer flatness during molding and provides enhanced protection, preventing warpage even in large diameter and thin wafer applications where conventional materials fail.
Solution Approach 2:
The patent changes the material state from solid to liquid, allowing the molding material to conform precisely to the wafer surface topology. This parameter change enables complete coverage and adhesion to thin wafers without causing warpage, while the subsequent curing process provides structural support for wafer protection.
4Ease of manufacture
If liquid epoxy resin is used for compression molding, then molding can be performed, but it is not easy to optimize the flow and physical properties of the liquid encapsulating resin
Solution Approach 1:
The patent uses a pre-formulated composite material system consisting of liquid silicone resin, epoxy resin, and filler particles in specific proportions. This composite formulation provides optimized flow properties and physical characteristics without requiring complex optimization processes, as the balanced composition delivers both ease of application and superior molding performance out of the box.
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 ensures satisfactory molding performance, adhesion, and minimal warpage, making it suitable for wafer-level packages and enabling the production of high-yield semiconductor devices with improved reliability and protection.
Implementation Method 1
a resin composition comprising (A) the silicone resin defined above, (B) an epoxy resin curing agent, and (C) a filler
Data Source
AI summary
A silicone resin comprising constitutional units represented by formula (1) and having a Mw of 3,000-500,000 contains 10-50 wt% of (A-1) a first silicone resin having a silicone content of 10-40 wt% and (A-2) a second silicone resin having a silicone content of 50-80 wt%. A resin composition comprising the silicone resin can be formed in film form, and it possesses satisfactory covering or encapsulating performance to large size/thin wafers. The resin composition or resin film ensures satisfactory adhesion, low warpage, and wafer protection. The resin film is useful in wafer-level packages.