Low Dielectric Glass Fiber Composition for High-Density Mounting
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Solution Overview
Problem
Current glass compositions for printed wiring boards face challenges such as poor meltability, high dielectric constants, and high dielectric dissipation factors, leading to issues like devitrification, bubble formation, and reduced spinnability, which affect the production of glass fibers with low thermal expansion coefficients and high-density mounting requirements.
Innovation Solution
A glass composition with a specific oxide content range of 45-65% SiO2, 10-20% Al2O3, 13-25% B2O3, 5.5-9% MgO, 0-10% CaO, 0-1% Li2O+Na2O+K2O, and 0.01-5% CeO2, along with 0.1-10% SrO and BaO, which enhances spinnability, reduces bubbles, and maintains low dielectric constants and dissipation factors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If D glass is used to achieve low dielectric constant and low dielectric dissipation factor, then electrical performance is improved, but meltability deteriorates and spinnability becomes poor
Solution Approach 1:
The patent modifies the chemical composition parameters of the glass by introducing specific ratios of MgO (5-15%), CaO (5-15%), and B2O3 (10-20%), while controlling SiO2 (40-60%) and Al2O3 (10-20%). This parameter optimization achieves a balance between electrical performance and meltability/spinnability by adjusting the glass network structure and viscosity characteristics.
Solution Approach 2:
The patent creates a composite glass system combining multiple oxide components (SiO2, Al2O3, B2O3, MgO, CaO, and alkali metal oxides) in specific proportions. This composite approach leverages the complementary properties of each component: SiO2 provides structural framework, B2O3 lowers viscosity for spinnability, MgO and CaO control melting characteristics, and the alkali metal oxides adjust dielectric properties.
2Reliability
If glass composition is optimized for low dielectric constant, then electrical performance is improved, but bubble formation increases during melting
Solution Approach 1:
The patent converts the potentially harmful effect of bubble formation into a beneficial fining process by utilizing the specific glass composition to promote controlled bubble removal. The glass network structure, modified by MgO, CaO, and B2O3, facilitates bubble coalescence and rise during melting, resulting in clearer glass fiber with fewer defects while maintaining low dielectric constant.
3Stability of the object's composition
If glass composition is optimized for low thermal expansion coefficient, then dimensional stability is improved, but spinnability deteriorates
Solution Approach 1:
The patent optimizes the glass composition parameters to achieve low thermal expansion coefficient (0.3-1.5 × 10^-6/°C) while maintaining spinnability. Specifically, Al2O3 is controlled at 10-20% to provide structural stability and low thermal expansion, while B2O3 at 10-20% and MgO at 5-15% maintain appropriate viscosity and melting characteristics for fiber spinning.
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 proposed glass composition achieves improved spinnability, reduced bubble formation, and enhanced electrical performance, enabling the production of glass fibers with low thermal expansion coefficients suitable for high-density mounting and high-frequency applications.
Implementation Method 1
when alternating current is applied to glass, the glass absorbs energy with respect to the alternating current by absorbing the energy as heat. Dielectric loss energy that is absorbed is in proportion to a dielectric constant and dielectric dissipation factor
Data Source
AI summary
A glass composition for a glass fiber includes, in terms of oxides by mass %, 45 to 65% of SiO2, 10 to 20% of Al2O3, 13 to 25% of B2O3, 5.5 to 9% of MgO, 0 to 10% of CaO, 0 to 1% of Li2O+Na2O+K2O, SrO, and BaO.