Substrate Contact Sealing Structure for Electroplating

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Solution Overview

Problem

Existing contact structures for substrates during electroplating fail to provide a strong and consistent sealing force, leading to dissolution of the seed layer due to exposure to plating solutions, particularly when the seed layer is thin and the contact periphery becomes wet.

Innovation Solution

A contact structure with a first contact portion on the leading end and a second contact portion closer to the base, a seal member covering the periphery, and independent pressing portions to apply contact pressure, where the first contact portion adheres to the seal member and the second contact portion is displaceable relative to it, ensuring effective sealing and preventing exposure to the plating solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hollow conical portion is added to the contact structure to improve sealing, then the sealing coverage area increases, but the device complexity and manufacturing difficulty increase significantly

Engineering Contradiction:

Improvesealing performanceVSAvoidcontact structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The contact structure is divided into distinct functional segments: a sealing portion with a sealing surface that contacts the substrate, and a contact portion that makes electrical contact. This segmentation allows each part to be optimized independently for its specific function while simplifying the overall structure compared to integrated complex designs.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The sealing function is extracted as a separate sealing portion distinct from the contact portion. The sealing portion includes a sealing surface that can be pressed against the substrate to create a seal, while the contact portion handles electrical conduction. This separation eliminates the need for complex hollow conical structures while maintaining effective sealing.

Inventive Principle:

Principle #2Taking out (Extraction)

2Device complexity

If the contact structure is integrated with the sealing structure to simplify design, then the device complexity decreases, but the sealing force becomes insufficient

Engineering Contradiction:

Improvestructure integrationVSAvoidsealing force

Core Design Contradiction:

Device complexityVSForce

Solution Approach 1:

The sealing portion is designed with specific local properties: a sealing surface with appropriate hardness and friction characteristics that enables it to be pressed against the substrate and maintain sealing pressure. The contact portion has different local properties optimized for electrical conduction. This local differentiation ensures sufficient sealing force while maintaining structural simplicity.

Inventive Principle:

Principle #3Local quality

3Manufacturing precision

If the seed layer is thinned to reduce circuit line width, then the manufacturing precision improves, but the seed layer becomes vulnerable to dissolution when exposed to plating solution

Engineering Contradiction:

Improvecircuit line width precisionVSAvoidseed layer dissolution

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The sealing portion is positioned to contact the substrate at locations including the periphery of electrical contacts before plating begins. This creates a protective seal that prevents plating solution from reaching and dissolving the thinned seed layer, thereby counteracting the harmful effect in advance while allowing the seed layer to be sufficiently thin for high-precision circuit fabrication.

Inventive Principle:

Principle #9Preliminary anti-action

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 configuration generates a sufficient sealing pressure that prevents the dissolution of the seed layer by minimizing exposure to the plating solution, maintaining the integrity of the substrate contacts and ensuring reliable plating processes even with thin seed layers.

Implementation Method 1

a seal member configured to cover a periphery of the substrate contact and to have a sealing surface that comes into contact with the substrate to seal the substrate contact; a first pressing portion configured to elastically apply a contact pressure on the substrate to the substrate contact

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

the first contact portion adheres to the seal member

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS11668018B2Contact structure, substrate holder, apparatus for plating, and method of feeding electric power to substrate

Publication Date: 2023.06.06 EBARA CORP

AI summary

There is provided a contact structure, comprising a substrate contact including a first contact portion that is located on a leading end side of the substrate contact and that comes into contact with a substrate and a second contact portion that is located nearer to a base end side of the substrate contact than the first contact portion; a seal member configured to cover a periphery of the substrate contact and to have a sealing surface that comes into contact with the substrate to seal the substrate contact; a first pressing portion configured to elastically apply a contact pressure on the substrate to the substrate contact; and a second pressing portion configured to come into contact with the seal member and to apply a contact pressure on the substrate to the seal member independently of the first pressing portion, wherein the first contact portion adheres to the seal member, and the second contact portion is fit in the seal member to be displaceable relative to the seal member.