Power Feeding Point Configuration for Rectangular Electroplating Substrates
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Solution Overview
Problem
Existing electroplating methods for rectangular substrates lack optimization in power feeding point location and number, leading to non-uniform metal film thickness due to non-uniform electric potential distribution, especially when using a square substrate.
Innovation Solution
A method to determine the optimal location and number of power feeding points on an auxiliary electrode based on the substrate area and dimensions, with specific conditions for different substrate areas to ensure uniform electric potential distribution and film thickness, including positioning power feeding points at the center and strategically along the auxiliary electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If power feeding portion is disposed only at center of anode, then device complexity is reduced, but manufacturing precision deteriorates due to non-uniform current distribution and non-uniform metal film thickness
Solution Approach 1:
The anode is divided into multiple independent power feeding portions (first, second, third, and fourth power feeding portions) positioned at different locations (center and outer peripheral portions). This segmentation allows independent control of current distribution across different regions of the anode, enabling uniform current flow and resulting in uniform metal film thickness across the substrate surface.
2Manufacturing precision
If multiple power feeding portions are added to anode, then manufacturing precision improves through uniform current distribution, but device complexity increases
Solution Approach 1:
Multiple power feeding portions are positioned at strategically selected locations on the anode (center and outer peripheral portions) to create equipotential regions. This ensures uniform electric potential distribution across the anode surface, which in turn produces uniform current distribution and uniform metal film deposition, justifying the increased device complexity through improved manufacturing precision.
3Ease of manufacture
If power feeding points are not optimized for square substrate, then ease of manufacture is improved, but manufacturing precision deteriorates due to non-uniform plating thickness
Solution Approach 1:
The power feeding portions are positioned at specific locations (center and outer peripheral portions) that are locally optimized for square substrates. This local quality approach ensures that each region of the anode contributes appropriately to uniform plating across the entire substrate surface, achieving both ease of manufacture and high manufacturing precision for square substrate geometries.
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 significantly improves the uniformity of metal film thickness on rectangular substrates by optimizing the power feeding point configuration, reducing thickness variations by up to 3.2% and achieving lateral and longitudinal symmetry in film thickness profiles.
Implementation Method 1
a general electroplating apparatus couples a substrate to a negative electrode of a power supply, couples an anode to a positive electrode of the power supply, and applies a voltage between the anode and the substrate to form a metal film on the substrate
Implementation Method 2
The auxiliary electrode is configured to assist the plating on the substrate. The power feeding element is configured to supply the auxiliary electrode with an electric power from the power supply
Data Source
AI summary
To optimize a location of a power feeding point with the use of a square substrate. There is disclosed a method for determining a location of a power feeding point in an electroplating apparatus. The electroplating apparatus is configured to plate a rectangular substrate having a substrate area of S. The rectangular substrate has opposed two sides coupled to a power supply. The rectangular substrate has a length L of the sides coupled to the power supply and a length W of sides not coupled to the power supply meeting a condition of 0.8×L≤W≤L. The method includes determining a number N of the power feeding points according to the substrate area S.