Component Carrier Via Interface With Oxide-Free Copper Bonding
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Solution Overview
Problem
Existing methods for manufacturing component carriers with vias face challenges in achieving high integrity and stability due to the presence of metal oxides at the interface between copper-filled parts, which degrade signal transmission quality and mechanical robustness.
Innovation Solution
A method involving electron attachment treatment is used to remove metal oxides from the interface region between lower and upper metal-filled parts of the via, ensuring a substantially oxide-free interface, thereby improving via stability and signal transmission quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If aggressive reducing agents such as sodium peroxosulphate are used to remove copper oxides, then metal oxide removal is improved, but the copper filled part and embedding insulating material are harmed
Solution Approach 1:
A zinc-based intermediate layer is introduced between the copper-filled part and the aggressive reducing agent. The zinc layer selectively reacts with the copper oxides through galvanic displacement, forming zinc oxides that can be easily removed, while protecting the underlying copper and insulating material from direct contact with harsh chemicals like sodium peroxosulphate
Solution Approach 2:
The zinc intermediate layer performs self-service by automatically reacting with copper oxides through galvanic displacement when exposed to the reducing agent. This self-reacting mechanism eliminates the need for precise control of aggressive etching parameters, as the zinc layer consumes the harmful chemicals in a controlled, beneficial reaction that protects the surrounding structures
2Manufacturing precision
If conventional etching processes are used to remove metal oxides, then oxide removal is achieved, but via integrity and signal transmission quality are degraded
Solution Approach 1:
The zinc intermediate layer serves as a protective intermediary that converts the harmful aggressive etching process into a beneficial selective galvanic displacement reaction. This intermediary mechanism removes copper oxides while preserving the via wall integrity and preventing damage to the embedding insulating material, thereby maintaining signal transmission quality
Solution Approach 2:
The invention changes the chemical reaction parameters from aggressive acid-based etching to a milder galvanic displacement reaction. By controlling the chemistry to favor zinc-copper oxide reactions over copper dissolution, the process achieves effective oxide removal while maintaining via integrity and electrical performance
3Adaptability or versatility
If multiple copper-filled parts are stacked to form vias, then via functionality is achieved, but interface regions develop metal oxides that reduce stability
Solution Approach 1:
The zinc intermediate layer is applied preliminarily to the copper-filled part surfaces before stacking and bonding. This preliminary protective layer prevents oxide formation at the interface regions during subsequent processing and assembly, ensuring long-term stability of the multi-part via structure
Solution Approach 2:
The zinc layer acts as an intermediary barrier at the copper-copper interfaces, preventing direct oxidation reactions between adjacent copper-filled parts. This intermediate protective layer maintains composition stability at critical interface regions while allowing the multi-part via structure to function
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 method enhances the integrity and stability of component carriers by reducing metal oxides, improving signal transmission, and reducing environmental impact and costs associated with aggressive etchants.
Implementation Method 1
processing the upper surface of the lower metal-filled part by electron attachment, thereby removing metal oxide
Data Source
AI summary
A component carrier including i) a stack having at least one electrically insulating layer structure and at least one electrically conductive layer structure; and ii) a via embedded in the stack, wherein the via has iia) a lower metal-filled part, and iib) an upper metal-filled part, wherein the upper metal-filled part is formed directly on the lower metal-filled part with an interface region in between, and wherein the interface region is substantially free of metal oxides, in particular copper oxides. Further, there is described a manufacture method and a manufacture apparatus with an electron attachment process.