Electroforming Mold Recess Geometry for Metal Thickness Control

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Solution Overview

Problem

Conventional electroforming methods face challenges in controlling the thickness of metal layers opposite to the electrodeposited surface on a mold, leading to unevenness and requiring post-processing polishing, which decreases efficiency and increases costs.

Innovation Solution

The method involves forming an insulating layer on a conductive base material with recessed parts, allowing metal deposition within these recessed areas, where the width and height of the recessed parts are specifically designed to control the metal layer growth, ensuring uniform thickness without the need for post-processing polishing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If metal is electrodeposited on the surface of the mold without proper control, then the metal layer is formed, but the thickness of the metal layer becomes uneven and the surface cannot be controlled

Engineering Contradiction:
Improvethickness uniformity of metal layerVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-forming recesses in the mold surface before electroforming. These recesses are strategically designed to compensate for the edge effect that causes metal layer bulging. By preparing the mold geometry in advance, the electroformed part achieves uniform thickness without requiring post-processing polishing, thus resolving the contradiction between manufacturing precision and process complexity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs parameter changes by modifying the mold geometry parameters - specifically creating recesses with controlled depth and dimensions. This geometric parameter adjustment allows the electroformed metal layer to achieve uniform thickness by compensating for electrical field distribution variations, thereby improving thickness uniformity while maintaining a relatively simple electroforming process

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If polishing is performed after electroforming to smooth the metal layer surface, then thickness uniformity is improved, but manufacturing efficiency decreases and cost increases

Engineering Contradiction:
Improvesurface uniformity of metal layerVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent performs the thickness control action preliminarily during the electroforming setup phase by designing recesses in the mold. This eliminates the need for subsequent polishing operations, as the metal layer emerges with uniform thickness directly from the electroforming process. The preliminary geometric preparation prevents the formation of uneven surfaces rather than correcting them afterward, thereby maintaining high manufacturing efficiency

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts the thickness control function from the post-processing stage and integrates it into the electroforming process itself. By incorporating recesses in the mold geometry, the thickness uniformity is achieved during the primary manufacturing step, eliminating the separate polishing operation and its associated time and cost costs

Inventive Principle:
Principle #2Taking out (Extraction)

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 approach allows for precise control of metal layer thickness, reducing variability and eliminating the need for polishing, thereby enhancing manufacturing efficiency and reducing costs while maintaining uniformity.

Implementation Method 1

an electrodepositing step of applying a voltage to the mold disposed in an electrolytic bath and electrodepositing a metal on an exposed surface of the conductive base material inside the recessed part

Methodology Applied
Scientific EffectElectrodeposition: Electrodeposition

Data Source

PatentEP2336393B1Electroforming method
Publication Date: 2019.02.20 OMRON CORP

AI summary

A mold 11 is fabricated with a cavity 15 formed in an insulating layer 14 formed so as to be placed on an upper surface of a conductive base material 13. This mold 11 is disposed in an electrolyte bath to be applied with a voltage, and a metal is electrodeposited on the bottom surface of the cavity 15 to electroform a metal-formed product 12 in the cavity 15. In this electrodepositing process, when the width of the cavity 15 is taken as W and a vertical height of a head space between an upper opening of the cavity 15 and an upper surface of a metal layer 18 is taken as H, the growth of the metal layer 18 is stopped so that the height H of the head space left above the metal layer 18 satisfies: H ≥ W/2.85 where 300 µm ≤ W; H ≥ W/3.75 where 200 µm ≤ W < 300 µm; H ≥ W/4 where 100 µm ≤ W < 200 µm; and H ≥ W/10 where W < 100 µm.