Composite Substrate Structure for 5G Antenna Warpage Reduction
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Solution Overview
Problem
Multilayer printed circuit boards often experience warpage during back-end packaging due to material coefficient of thermal expansion differences, affecting their flatness and reliability, which can reduce the performance of 5G antennas in terms of size, air cavity, receiving capability, and bandwidth.
Innovation Solution
A composite substrate structure comprising a circuit substrate, a first anisotropic conductive film, a first glass substrate with conductive vias, a dielectric layer, and a patterned circuit layer, where the glass substrate is positioned on both sides of the anisotropic conductive film to enhance flatness and reliability, and a manufacturing method involving lamination and formation of conductive vias and layers to improve yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a multilayer printed circuit board is used, then electrical connectivity and circuit functionality are achieved, but warpage occurs during back-end packaging due to CTE differences, affecting flatness and reliability
Solution Approach 1:
The patent applies composite materials by combining glass substrates with anisotropic conductive films to create a composite substrate structure. The glass substrate provides dimensional stability and low CTE, while the anisotropic conductive film provides electrical connectivity. This composite structure resolves the contradiction by maintaining flatness through the glass substrate's mechanical properties while achieving reliability through the combined structural and electrical functionality.
Solution Approach 2:
The patent applies local quality by using anisotropic conductive films with directionally selective conductivity. The film allows electrical conduction in the vertical direction (through the thickness) while maintaining mechanical stability in the horizontal plane. This localized functional differentiation enables the structure to achieve both flatness (through horizontal mechanical stability) and reliability (through vertical electrical connectivity).
2Productivity
If the multilayer printed circuit board has poor flatness, then manufacturing complexity increases, but the receiving capability and bandwidth of the 5G antenna are reduced
Solution Approach 1:
The composite substrate structure using glass and anisotropic conductive film maintains excellent flatness, which ensures both high manufacturing yield and optimal 5G antenna performance. The glass substrate's inherent dimensional stability prevents warpage, thereby maintaining the air cavity geometry required for antenna functionality while enabling efficient back-end packaging processes.
Solution Approach 2:
The patent applies parameter changes by selecting materials with specific thermal and mechanical properties. The glass substrate has a low and stable CTE, while the anisotropic conductive film has tailored conductivity parameters. By changing and optimizing these material parameters, the structure achieves both manufacturing efficiency (high yield) and antenna performance (receiving capability and bandwidth).
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 structure achieves better flatness and reliability, reducing warpage and enhancing the performance of 5G antennas by maintaining the receiving capability and bandwidth, while the manufacturing method improves yield and mechanical properties.
Implementation Method 1
a first anisotropic conductive film, wherein the first anisotropic conductive film is disposed on the circuit substrate and the first glass substrate is disposed on the first anisotropic conductive film
Data Source
AI summary
A composite substrate structure includes a circuit substrate, a first anisotropic conductive film, a first glass substrate, a dielectric layer, a patterned circuit layer and a conductive via. The first anisotropic conductive film is disposed on the circuit substrate. The first glass substrate is disposed on the first anisotropic conductive film and has a first surface and a second surface opposite to the first surface. The first glass substrate includes a first circuit layer, a second circuit layer and at least one first conductive via. The first circuit layer is disposed on the first surface. The second circuit layer is disposed on the second surface. The first conductive via penetrates the first glass substrate and is electrically connected to the first circuit layer and the second circuit layer. The first glass substrate and the circuit substrate are respectively located on two opposite sides of the first anisotropic conductive film.