PCB Warpage Control via Composite Outer Layers
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Solution Overview
Problem
Printed circuit boards (PCBs) face challenges with warpage due to differences in physical properties between layers and embedded electronic elements, especially as they become thinner and more complex, requiring improved heat radiation and stability characteristics.
Innovation Solution
A PCB design with an inner layer of insulating material and outer layers of higher rigidity, including an Fe—Ni alloy reinforcing layer, to enhance structural integrity and warpage resistance, along with a manufacturing method involving the stacking and lamination of insulating and reinforcing layers with pressure application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the PCB is made thinner to meet miniaturization demands, then the size of electronic products is reduced, but warpage intensifies due to unpredictable physical property differences between layers
Solution Approach 1:
The patent applies composite materials by combining multiple insulating layers with different physical properties (modulus of elasticity, thermal expansion coefficient) to create a multi-layer PCB structure. This composite approach allows the thin PCB to maintain structural stability and resist warpage while meeting miniaturization requirements, as the different material properties complement each other to balance internal stresses.
Solution Approach 2:
The patent implements local quality by strategically positioning insulating layers with different rigidity characteristics at specific locations within the PCB structure. The first insulating layer with higher modulus of elasticity is placed in regions requiring greater structural support, while the second insulating layer is positioned in areas where flexibility is acceptable, thereby locally optimizing warpage resistance without increasing overall thickness.
2Volume of moving object
If wiring patterns are narrowed to achieve miniaturization, then electronic product size is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent uses composite insulating layers with different material properties to provide enhanced structural support and dimensional stability, which enables the formation of narrower wiring patterns with tighter pitch. The composite structure maintains flatness and reduces distortion during manufacturing processes, thereby achieving the required manufacturing precision for fine wiring.
3Temperature
If multiple layers with different physical properties are stacked to improve heat radiation and stability, then heat dissipation performance is enhanced, but warpage occurs due to physical property differences between layers
Solution Approach 1:
The patent employs composite materials with carefully selected physical properties for each insulating layer. The first insulating layer has a higher modulus of elasticity to provide structural stability, while the second insulating layer complements it with different thermal and mechanical properties. This composite structure enables effective heat radiation across multiple layers while the coordinated physical properties minimize differential expansion and contraction, thereby preventing warpage.
Solution Approach 2:
The patent applies parameter changes by adjusting the modulus of elasticity and thermal expansion coefficients of the insulating layers. The first insulating layer is designed with a higher modulus of elasticity parameter to resist deformation, while the second layer has different parameters optimized for thermal management. By changing and coordinating these material parameters, the patent achieves both heat radiation performance and warpage resistance.
Data Source
AI summary
A printed circuit board and a method of manufacturing the same are provided. The printed circuit board includes an inner layer including at least one insulating layer and wiring parts, and outer layers disposed on opposing sides of the inner layer, the outer layers including reinforcing layers and wiring parts, the reinforcing layers having a greater degree of rigidity than the insulating layer.