Composite Substrate Resin-Ceramic Integration for Low Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ceramic multilayer substrates for mobile communication modules face challenges in reducing size and profile while maintaining strength and reliability, particularly due to the presence of a thick air layer which is difficult to remove and results in low impact resistance.
Innovation Solution
A composite substrate is developed with a resin layer interposed between ceramic layers, incorporating interlayer connection metal conductors that integrate with the ceramic layers, utilizing a resin material with low permittivity and a specific metal content to enhance bonding strength and reduce transmission loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If an air layer is used as a low dielectric material to reduce transmission loss, then transmission loss is reduced, but impact strength decreases and size reduction is limited due to the need for thick air layers (300 μm or more)
Solution Approach 1:
The patent changes the physical state and material properties of the low dielectric layer from an air-filled cavity (requiring 300 μm or more thickness) to a resin-based material with controlled permittivity (2.0-4.0). This parameter change allows the same electrical function to be achieved with much thinner layers (10-100 μm), simultaneously improving impact strength while maintaining low transmission loss characteristics
Solution Approach 2:
The patent creates a composite structure where a resin material is impregnated into a porous body (such as a ceramic green sheet with hollow pores). This composite material combines the low dielectric properties of the resin with the structural support of the porous substrate, achieving both low transmission loss and high impact strength that neither material could provide alone
2Loss of energy
If an air layer is used to reduce transmission loss, then electrical characteristics are improved, but the substrate size and profile cannot be sufficiently reduced
Solution Approach 1:
By changing from air (permittivity ≈1.0) to resin materials with optimized permittivity (2.0-4.0) and controlling the density and porosity of the composite structure, the patent achieves low dielectric loss with significantly reduced thickness. The resin-impregnated porous body maintains electrical performance while reducing the low dielectric layer thickness to 10-100 μm, enabling compact substrate design
3Ease of manufacture
If a thick air layer (300 μm or more) is used to compensate for the reaction layer at the interface, then manufacturing is feasible, but the substrate thickness increases and impact strength decreases
Solution Approach 1:
The patent uses a composite structure where resin is impregnated into a porous body to create a mechanically robust low dielectric layer. The porous substrate provides structural integrity and bonding area, while the resin fills the pores to provide low dielectric properties. This composite approach eliminates the need for thick compensatory layers, reducing overall thickness to 10-100 μm while maintaining manufacturability and improving impact strength
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 composite substrate achieves higher impact strength, reduced size and profile, and improved high-frequency characteristics by using a resin layer with low permittivity and integrated metal conductors, addressing the limitations of ceramic substrates with air layers.
Implementation Method 1
The resin layer serves as a stress relaxation layer and, therefore, when the resin layer is disposed, a composite substrate can have higher strength against impact than the case in which an air layer interposed between the ceramic layers is located
Implementation Method 2
This integration signifies that an intermetallic bonding state between the metal conductor in the ceramic layer and the metal conductor in the resin layer is the same as the intermetallic bonding state between the metal conductors in a plurality of ceramic layers
Implementation Method 3
a transmission loss in a high-frequency region can be reduced by using a resin material having low permittivity (for example, relative permittivity εr of 2 or less) that is difficult for a ceramic material to realize
Data Source
AI summary
A composite substrate that is composed of a resin layer including an interlayer connection metal conductor and multiple ceramic layers that each include interlayer connection metal conductor, such that the resin layer is interposed between the ceramic layers, and the interlayer connection metal conductor in the resin layer is integrated with the interlayer connection metal conductors in the ceramic layers.