Embedded Circuit Board Structure to Block Copper Diffusion
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Solution Overview
Problem
The increasing demand for thinner and lighter electronic communication products with shorter circuit pitches leads to copper atom diffusion between adjacent circuits, increasing leakage current and reducing reliability, while current planarization processes like CMP are costly.
Innovation Solution
A circuit board design with a conductive structure embedded in insulation layers, featuring a metal layer and diffusion barrier layer recessed within the insulation, bypassing costly CMP through wet etching and deposition processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pitch between circuits is shortened to increase circuit density, then circuit density is improved, but copper atom diffusion between adjacent circuits increases, leading to increased leakage current and reduced reliability
Solution Approach 1:
A diffusion barrier layer is introduced as an intermediary between the copper circuit layer and the insulation layer. This barrier layer acts as a mediator that blocks copper atom diffusion while allowing the circuit pitch to be reduced for higher density, thus resolving the contradiction between productivity and reliability
2Shape
If planarization processes like CMP are used to flatten circuit board surfaces, then surface flatness is improved, but manufacturing cost increases significantly
Solution Approach 1:
The costly CMP planarization process is extracted and replaced from the manufacturing sequence. Instead, a wet etching process is used to create recessed conductive structures, eliminating the need for expensive CMP while achieving the required surface flatness and structural precision
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
Reduces manufacturing costs by eliminating the need for CMP and effectively prevents copper diffusion, maintaining circuit reliability.
Implementation Method 1
the diffusion barrier layer should be disposed on the outer layer of the circuit... the diffusion barrier layer is disposed between the metal layer and the second insulation layer and surrounds an outer surface of the metal layer
Implementation Method 2
bypassing costly CMP through wet etching and deposition processes
Implementation Method 3
bypassing costly CMP through wet etching and deposition processes
Data Source
AI summary
A circuit board and a method for fabricating the circuit board are provided. The circuit board includes a first insulation layer, a circuit layer, a second insulation layer and at least one conductive structure. The circuit layer is embedded in the first insulation layer, and the second insulation layer is disposed on the first insulation layer. The conductive structure has a first surface and a second surface opposite to each other, and the conductive structure is embedded in the second insulation layer. A flat surface of the second insulation layer exposes the second surface of the conductive structure, and the second surface is recessed to the flat surface of the second insulation layer. The conductive structure includes the metal layer and the diffusion barrier layer. The diffusion barrier layer is disposed between the metal layer and the second insulation layer and surrounds the outer surface of the metal layer.