Electronic-Grade Glass Fiber Composition for Low Dielectric Constant

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Solution Overview

Problem

Conventional electronic-grade glass fibers face challenges such as high raw material costs, volatility, poor mechanical properties, and inadequate water resistance, making them unsuitable for large-scale production and high-performance electronic applications.

Innovation Solution

A specific electronic-grade glass fiber composition with controlled ratios of SiO2, Al2O3, B2O3, CaO, MgO, and alkali metal oxides, which reduces raw material costs and volatility, improves dielectric and mechanical properties, and expands the temperature range for fiber formation, suitable for large-scale tank furnace production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If D-glass fiber with high boron content (20-25% B2O3) is used to achieve low dielectric constant and good dielectric properties, then dielectric properties are improved, but forming temperature increases to more than 1400°C making large-scale tank furnace production difficult, and drilling performance and water resistance deteriorate

Engineering Contradiction:
Improvedielectric propertiesVSAvoidforming temperature and processability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the chemical composition parameters of the glass fiber, specifically controlling B2O3 content at 7.0-10.0% (lower than conventional D-glass), SiO2 at 65.0-75.0%, and adding specific amounts of Al2O3 (3.0-8.0%), CaO (5.0-15.0%), and MgO (2.0-10.0%). This parameter optimization achieves dielectric constant ≤4.5 while reducing forming temperature to 1200-1400°C and improving mechanical properties

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite glass composition by combining multiple oxides in specific ratios: SiO2 as the base (65-75%), B2O3 for dielectric properties (7-10%), Al2O3 for mechanical strength (3-8%), CaO for melting performance (5-15%), and MgO for chemical stability (2-10%). This composite approach balances dielectric performance with manufacturability

Inventive Principle:
Principle #40Composite materials

2Reliability

If conventional E-glass fiber with high boron content (B2O3 7.2% ±0.4%) is used to meet dielectric requirements, then dielectric constant (6.7-7.1) is acceptable for conventional PCBs, but raw material costs increase, volatility accelerates high-temperature corrosion of refractories, and mechanical properties and water resistance deteriorate

Engineering Contradiction:
Improvedielectric constantVSAvoidraw material cost and volatility
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent optimizes the B2O3 content parameter to 7.0-10.0%, which is slightly lower and more controlled than conventional E-glass (7.2% ±0.4%). This parameter adjustment reduces raw material costs, decreases batch volatility, and lessens high-temperature corrosion of refractories while maintaining dielectric constant ≤4.5

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the potentially harmful high volatility of boron-containing glass into a benefit by precisely controlling the B2O3 content range and balancing it with other oxides. The controlled composition reduces volatility and corrosion while maintaining the dielectric properties, turning a problematic characteristic into an optimized feature

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If boron-free E-glass fiber is used to reduce cost and improve mechanical properties, then production difficulty is lowered and production efficiency is raised, but electrical properties and drilling performance fail to meet PCB requirements

Engineering Contradiction:
Improveproduction efficiencyVSAvoidelectrical properties
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the composition parameter by including B2O3 (7.0-10.0%) rather than eliminating boron entirely. This controlled boron content achieves dielectric constant ≤4.5 and good electrical properties while maintaining reasonable production efficiency and cost, finding an optimal middle ground between boron-free and high-boron compositions

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11919802B2Electronic-grade glass fiber composition, and glass fiber and electronic fabric thereof
Publication Date: 2024.03.05 JUSHI GRP CO

AI summary

An electronic-grade glass fiber composition includes the following components with corresponding amounts by weight percentages 51.0-57.5% SiO2, 11.0-17.0% Al2O3, >4.5% and ≤6.4% B2O3, 19.5-24.8% CaO, 0.1-1.9% MgO, 0.05-1.2% R2O=Na2O+K2O+Li2O, 0.05-0.8% Fe2O3, 0.01-1.0% TiO2, and 0.01-1.0% F2. A weight percentage ratio C1=SiO2/B2O3 is 8.1-12.7, a weight percentage ratio C2=B2O3/(R2O+MgO) is 1.7-6.3, and a total weight percentage of the above components is greater than or equal to 99%.