Embedded Circuit Board Component Surface Roughening
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Solution Overview
Problem
Printed circuit boards face delamination issues due to weak adhesion between embedded components and the surrounding prepreg layer, particularly with silver-plated copper wires, which are prone to detachment under thermal and mechanical loads, limiting their use in high-temperature applications.
Innovation Solution
The surface of conductor wires or plate-shaped molded parts is roughened before applying the cover layer, enhancing adhesion by creating a micro-rough surface topography that complements the prepreg layer, ensuring secure integration without delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silver-plated copper wires are used for high conductivity and ease of welding, then electrical conductivity and weldability are improved, but adhesion to the prepreg layer deteriorates due to the smooth silver surface
Solution Approach 1:
The patent applies different surface treatments to different parts of the wire: the contact points for welding remain smooth and silver-plated for good electrical conductivity and weldability, while the surrounding surface is roughened to enhance adhesion to the prepreg layer. This local differentiation resolves the contradiction between conductivity and adhesion.
Solution Approach 2:
The roughening treatment is performed in advance on the wire surface before the lamination process. This preliminary action creates a micro-rough surface structure that will enhance adhesion when the prepreg is applied, without affecting the subsequent welding process at the contact points.
2Productivity
If components are embedded in the prepreg layer to achieve three-dimensional circuit geometries, then integration density is improved, but delamination risk increases at the interfaces between components and prepreg
Solution Approach 1:
The patent creates a local quality difference on the component surfaces: areas that will contact the prepreg layer are roughened to enhance adhesion, while areas designated for welding contact points maintain their original smooth finish. This allows embedded components to achieve both high integration density and delamination resistance.
Solution Approach 2:
The surface roughening is performed as a preliminary step before component embedding and lamination. This advance treatment ensures that when components are embedded in the prepreg layer, they already have optimized adhesion surfaces, preventing delamination while maintaining the ability to weld at designated contact points.
3Strength
If the surface of conductor wires is roughened to improve adhesion, then adhesion strength is improved, but the quality of contact at welding points may deteriorate
Solution Approach 1:
The patent precisely controls the surface roughness distribution: the bulk of the wire surface is roughened to maximize adhesion area, while specific localized contact points remain smooth to ensure optimal welding quality. This spatial differentiation of surface properties resolves the contradiction between adhesion strength and contact quality.
Solution Approach 2:
The roughening process is designed and executed in advance with precise control over which areas are treated. By performing this preliminary action with spatial selectivity, the patent ensures that adhesion is enhanced where needed while welding contact points remain intact for high-quality electrical connection.
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
This method significantly improves adhesion between embedded components and the cover layer, preventing delamination and enabling the integration of components in multilayer printed circuit boards, even in extreme environmental conditions, such as high-temperature applications, by maintaining the quality of contact and allowing for high-throughput processing.
Implementation Method 1
The adhesion between the component and the covering component Top layer can thus be significantly improved
Data Source
Figure 1a~1b
AI summary
The present invention relates to a method for producing a circuit board element and to a corresponding circuit board element with which it is possible to suppress the risk of delamination in the region of a component (e.g. a wire or a plate-shaped moulded part) that is embedded in the circuit board. To this end, according to the invention the surface of the component is at least partially roughened, in order to ensure a better adhesive bond with the surrounding cover layer (e. g. a prepreg made of insulating material compound). The component surface can be roughened by chemical methods such as etching or by purely mechanical methods such as sand blasting.