Polycarbonate Electronic Substrate Material for Low-Loss High-Frequency Wiring
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Solution Overview
Problem
Existing electronic substrate materials face challenges with high transmission loss, dielectric loss, and insufficient adhesion to metal wiring, particularly at high frequencies, due to unsuitable dielectric properties and thermal expansion coefficients, which affect energy efficiency and substrate stability.
Innovation Solution
A polycarbonate resin with specific structural units and controlled terminal hydroxyl group content, combined with a crosslinking structure and inorganic fillers, is developed to achieve low dielectric properties, reduced thermal expansion, and improved adhesion, using methods like interfacial polycondensation and melt transesterification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional polycarbonate resin (bisphenol A or bisphenol Z) is used, then mechanical properties and thermal resistance are improved, but dielectric properties worsen resulting in high transmission loss at high frequencies
Solution Approach 1:
The invention changes the chemical structure parameters of polycarbonate resin by introducing specific structural units (formula 1) with cyclic carbonate groups and controlling terminal hydroxyl group content to 6,000 ppm or less. This structural modification achieves both low dielectric properties (Dk ≤ 2.6, Df ≤ 0.0032 at 10 GHz) and high heat resistance (Tg ≥ 150°C), resolving the contradiction between heat resistance and transmission loss
Solution Approach 2:
The invention creates a composite resin system combining polycarbonate base resin with controlled amounts of specific structural units and optional thermosetting groups. This composite structure integrates the thermal stability of polycarbonate with the low dielectric properties of cyclic carbonate structures, achieving both high heat resistance and low transmission loss simultaneously
2Strength
If conventional polycarbonate resin is used, then mechanical strength is improved, but solubility in organic solvents and solution stability deteriorate
Solution Approach 1:
The invention modifies the chemical parameters of polycarbonate resin by introducing structural units with cyclic carbonate groups and precisely controlling terminal hydroxyl group content to 6,000 ppm or less. This parameter optimization maintains mechanical strength while dramatically improving solubility in non-halogenated solvents and solution stability, enabling coating and molding applications
3Loss of energy
If dielectric constant and dissipation factor are reduced to lower transmission loss, then energy loss is improved, but adhesion to metal foil or metal plating deteriorates
Solution Approach 1:
The invention applies local quality modification by introducing thermosetting groups (epoxy, allyl, maleimide, oxazole, cyclobutene, isocyanate, or cyanate ester) at specific locations within the polycarbonate chain. These localized functional groups provide adhesion sites for metal foil and plating while the bulk polymer maintains low dielectric properties, achieving both low transmission loss and high adhesion strength
Solution Approach 2:
The invention creates a composite resin system combining low-dielectric polycarbonate structural units with adhesion-promoting thermosetting groups. This composite structure integrates the low loss properties of cyclic carbonate structures with the adhesion capabilities of reactive functional groups, simultaneously achieving low dielectric loss and high metal adhesion
4Stability of the object's composition
If thermal expansion coefficient is reduced to prevent substrate warping, then dimensional stability is improved, but processing difficulty increases
Solution Approach 1:
The invention optimizes chemical structure parameters by introducing cyclic carbonate structural units and controlling molecular weight and terminal hydroxyl content. These parameter changes reduce thermal expansion coefficient and improve dimensional stability while maintaining processability through controlled solution viscosity and solvent compatibility
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 resin exhibits low dielectric constants and dissipation factors, maintaining stability across temperature variations, enhancing signal transmission and preventing substrate deformation, while being easily processable and solvent-soluble.
Implementation Method 1
The dielectric loss is proportional to the square root of the dielectric constant (Dk) of the dielectric and to the dissipation factor (Df) of the dielectric
Implementation Method 2
reacting a bischloroformate monomer or oligomer having a structure represented by the formula (UN1) with a bisphenol compound by interfacial polycondensation
Implementation Method 3
low thermal expansion to prevent warping of the substrate due to the difference in thermal expansion coefficient between the copper circuit and the insulating layer
Data Source
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AI summary
An electronic substrate material containing a resin having a structure represented by Formula (UN1). In Formula (UN1): R1 and R2 each independently represent at least one selected from the group consisting of a halogen atom and an organic group having 1 to 12 carbon atoms, and n represents 1, 2, 3, or 4; at least one R1 and at least one R2 may be an identical group or mutually different groups; and * each represent a bond.