Crystalline Siliceous Filler with Amorphous Silica Shell for Resin
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional resinous compositions used in electronic packaging face challenges with thermal expansion and warpage due to high thermal expansion coefficients, and existing fillers like amorphous silica have limitations such as ion diffusion and synthesis costs, while crystalline siliceous materials can cause yellowing and hardening issues when dispersed.
Innovation Solution
A filler comprising crystalline siliceous materials with specific crystal structures, treated to inhibit activity and ion elution, is used to achieve a negative thermal expansion coefficient, reducing thermal expansion and improving resinous composition performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If amorphous silica particles are used as fillers, then thermal expansion coefficient is reduced and insulating properties are improved, but ion diffusion occurs and electrical properties deteriorate
Solution Approach 1:
A shell made of amorphous silica material is formed on the surface of the crystalline siliceous material core. This shell acts as a barrier that prevents ion diffusion from the core while maintaining the negative thermal expansion coefficient properties of the core material.
Solution Approach 2:
The invention uses a composite structure with a core of crystalline siliceous material (providing negative thermal expansion) and a shell of amorphous silica material (providing ion barrier properties). This composite structure combines the advantages of both materials while eliminating their individual disadvantages.
2Reliability
If crystalline siliceous materials are dispersed in resinous composition, then negative thermal expansion coefficient is achieved, but yellowing and hardening issues occur
Solution Approach 1:
The amorphous silica shell encapsulates the crystalline siliceous material core, preventing direct contact between the core and the resinous composition. This isolation prevents the yellowing and hardening reactions while allowing the core to exert its negative thermal expansion effect on the overall composition.
Solution Approach 2:
The amorphous silica shell serves as an intermediary layer between the crystalline siliceous material and the resinous composition. It mediates the interaction by preventing harmful chemical reactions while transmitting the physical effect of negative thermal expansion to the surrounding resin.
3Reliability
If β-eucryptite is used as filler, then negative thermal expansion coefficient is achieved, but electric properties are insufficient due to Li ion diffusion
Solution Approach 1:
The amorphous silica shell forms a protective barrier around the β-eucryptite core, preventing Li ions from diffusing out into the resinous composition. This maintains the electrical insulation properties while preserving the negative thermal expansion characteristics of the β-eucryptite core.
Solution Approach 2:
The invention creates a composite structure combining β-eucryptite core (for negative thermal expansion) with amorphous silica shell (for ion barrier and electrical insulation). This composite approach leverages the strengths of both materials while mitigating their weaknesses.
4Reliability
If zirconium tungstate is used as filler, then negative thermal expansion coefficient is achieved, but synthesis time and cost increase significantly
Solution Approach 1:
The invention uses crystalline siliceous materials that can be produced more economically and with shorter synthesis times compared to zirconium tungstate. The amorphous silica shell is also formed through a relatively simple sol-gel process, making the overall filler more cost-effective for industrial production.
Solution Approach 2:
The invention changes the material parameters by selecting crystalline siliceous materials with specific crystal structures (FAU, FER, LTA, MFI, CHA, or MWW types) that exhibit negative thermal expansion. These materials offer a more favorable balance between performance and manufacturability compared to zirconium tungstate.
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 filler effectively reduces thermal expansion coefficients, inhibits yellowing and ion diffusion, and enhances adhesion and machining properties of resinous compositions, improving the reliability and performance of electronic device packaging materials.
Implementation Method 1
an application of materials, whose thermal expansion coefficient is lower than that of amorphous silica and which exhibit a negative thermal expansion coefficient and contract upon being subjected to heat
Data Source
AI summary
A filler for resinous composition is contained and used in resinous composition constituting electronic packaging material for electronic device, and includes: a filler ingredient including a crystalline siliceous material with a crystal structure made of at least one member selected from the group consisting of type FAU, type FER, type LTA, type MFI and type CHA, and/or type MWW, wherein: the filler ingredient is free of any activity when evaluated by an “NH3-TPD” method; and includes the crystalline siliceous material in an amount falling in a range allowing the filler ingredient to exhibit a negative thermal expansion coefficient. The filler ingredient may further be free of a surface in which silver, copper, zinc, mercury, tin, lead, bismuth, cadmium, chromium, cobalt and nickel are exposed.