Flexible Copper Clad Laminate for Low-Loss High-Frequency Transmission
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Solution Overview
Problem
Existing flexible copper clad laminates for high-frequency transmission suffer from increased insertion loss due to the magnetic properties and low conductivity of nickel, causing signal incompleteness during high-frequency transmission.
Innovation Solution
A flexible copper clad laminate is developed using a nickel-copper alloy layer formed by electroless plating, with a specific weight ratio of copper to nickel (1.3-2.3) and phosphorus content (2.1-3.0 wt%) to reduce magnetic permeability and insertion loss, combined with a copper layer for improved conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a nickel layer is formed on the polyimide substrate to increase peeling strength, then the structural strength is improved, but the magnetic property and low conductivity of nickel cause increased insertion loss during high-frequency transmission
Solution Approach 1:
The patent changes the chemical composition parameters of the metal conducting layer by forming a nickel-copper alloy with specific ratios (Ni: 65-85 wt%, Cu: 15-35 wt%) instead of using pure nickel. This parameter change reduces the magnetic permeability and improves conductivity, thereby reducing insertion loss during high-frequency transmission while maintaining adequate peeling strength through the controlled alloy composition.
Solution Approach 2:
The patent creates a composite metal conducting layer by combining nickel and copper in a specific alloy ratio, rather than using a single metal material. This composite approach allows the layer to simultaneously achieve good adhesion to the polyimide substrate (from nickel) and reduced magnetic properties with improved conductivity (from copper), resolving the contradiction between peeling strength and high-frequency transmission performance.
2Loss of energy
If a nickel-copper alloy layer is used to reduce magnetic permeability, then the insertion loss is reduced, but the manufacturing precision must be controlled to achieve the specific weight ratio and phosphorus content
Solution Approach 1:
The patent employs electroless plating technology where the nickel-copper alloy layer forms automatically through a self-catalyzed chemical reaction process. The plating solution contains nickel salts, copper salts, and reducing agents that react on the polyimide substrate surface to deposit the alloy layer with controlled composition (Ni: 65-85 wt%, Cu: 15-35 wt%, P: 2-5 wt%). This self-service mechanism achieves precise composition control without requiring complex external manipulation, thereby reducing manufacturing precision requirements while maintaining the desired low magnetic permeability and reduced insertion loss.
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 laminate reduces insertion loss in the frequency range of 1-4 GHz, ensuring effective high-frequency transmission without resonance absorption, and maintains structural integrity through controlled etching processes.
Implementation Method 1
a nickel-copper alloy layer formed on at least one surface of the polyimide substrate by electroless plating
Data Source
AI summary
Provides a flexible copper clad laminate, including a polyimide substrate; a nickel-copper alloy layer formed on at least one surface of the polyimide substrate by electroless plating, wherein the nickel-copper alloy layer includes nickel, copper and phosphorus, and in the nickel-copper alloy layer, the weight ratio of the copper/the nickel is greater than 1.3 and less than 2.3, and the content of the phosphorus is greater than 2.1 wt % and less than 3.0 wt %; and a copper layer formed on one surface of the nickel-copper alloy layer far away from the polyimide substrate and combined with the nickel-copper alloy layer to form a metal conducting layer. In addition, the flexible copper clad laminate is suitable for high-frequency transmission and beneficial to manufacturing a flexible circuit board suitable for the high-frequency transmission.