Electroforming Mold Multistage Structure for Uniform Deposition

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Solution Overview

Problem

Existing electroforming methods face challenges in manufacturing multistage structures with precise height control and surface roughness, often resulting in gaps, defects, and uneven interfaces within electroformed components due to electric field concentration and lack of electrodes on side walls.

Innovation Solution

A method involving the formation of an electroforming mold with a multistage structure using a sequence of photoresist layers and intermediate conductive films, where photoresist layers are exposed and developed in an overlapping manner with the intermediate conductive films acting as electrodes, allowing for precise control and uniform deposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If electroforming is executed simultaneously from side surfaces and bottom surface of the mold, then productivity is improved, but electric field concentration occurs at the top surface causing high electroforming rate and potential gaps or connections in the electroformed object

Engineering Contradiction:
Improveelectroforming rateVSAvoiduniformity of electroformed object
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The electroforming process is segmented into multiple stages with different electrode configurations. In the first stage, electrodes are formed only on the bottom surface to achieve uniform deposition. In the second stage, electrodes are added to side surfaces after the first stage completion, allowing controlled sequential electroforming that prevents electric field concentration and ensures uniform thickness throughout the electroformed object.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Electrodes are preliminarily formed only on the bottom surface before side surface electrodes are added. This preliminary configuration ensures that the electroformed object achieves uniform thickness in the first stage, and subsequent electrode addition to side surfaces does not cause electric field concentration, as the bottom electrodes are already in place to maintain balanced electric field distribution.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If electrodes are formed on all surfaces of the resin mold, then electroforming can proceed from multiple directions, but unnecessary portions must be removed and the process becomes complex

Engineering Contradiction:
Improveelectroforming efficiencyVSAvoidmold structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The electrode formation process is segmented into two distinct stages. First, electrodes are formed only on the bottom surface of the resin mold to create the initial electroformed structure. Second, after the first stage electroforming is complete, electrodes are formed on the side surfaces. This segmentation eliminates the need for complex multi-directional electrode configurations while maintaining electroforming efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bottom surface electrodes are formed preliminarily before side surface electrodes are added. This preliminary action establishes the foundation for uniform electroforming, and subsequent side surface electrode addition completes the structure without requiring complex simultaneous multi-directional electrode formation, thereby simplifying the overall process.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If multiple electroforming stages are executed sequentially, then manufacturing precision is improved, but production time increases

Engineering Contradiction:
Improvethickness control accuracyVSAvoidproduction cycle time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The electroforming process is divided into two stages: first stage with bottom surface electrodes only, and second stage with additional side surface electrodes. This segmentation enables precise thickness control by addressing different regions in separate controlled steps, preventing electric field concentration that would occur in simultaneous multi-directional electroforming.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Bottom surface electrodes are formed preliminarily to establish uniform electric field distribution and controlled deposition rate. This preliminary configuration enables precise thickness control in the first stage, and the second stage builds upon this foundation without requiring time-consuming simultaneous multi-directional electroforming, thus balancing precision with production efficiency.

Inventive Principle:
Principle #10Preliminary 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 approach enables the rapid manufacturing of electroformed components with improved strength and accuracy, reducing the need for multiple electroforming stages and minimizing defects, while maintaining uniform thickness and surface quality.

Implementation Method 1

thermally depositing a conductive material by using a vacuum deposition method

Methodology Applied
Scientific EffectVacuum deposition: Physical Vapour Deposition

Implementation Method 2

exposing the first photoresist layer to light through a first mask pattern disposed above the first photoresist layer to divide the first photoresist layer into a first soluble portion and a first insoluble portion

Methodology Applied
Scientific EffectPhotoexposure: Photography

Implementation Method 3

a conductive film is deposited on the surface of resin onto which the shape of a prototype is impress-patterned

Methodology Applied
Scientific EffectElectroforming: Electrodeposition

Data Source

PatentEP2053146B1Method for manufacturing electroformed mold, electroformed mold, and method for manufacturing electroformed parts
Publication Date: 2016.08.31 SEIKO INSTR INC
  • EP2053146B1 patent drawingFigure 1(a)~1(g)
  • EP2053146B1 patent drawingFigure 2(a)~2(c)
  • EP2053146B1 patent drawingFigure 3

AI summary

In a method of manufacturing an electroforming mold, a first photoresist layer is formed on an upper surface of a bottom conductive film 2 of a substrate 1, and the first photoresist layer 3 is divided into a soluble portion 3b and an insoluble portion 3a. Next, a conductive material is thermally deposited on an upper surface of the first photoresist layer within a temperature range in which light with a wavelength within a range not causing photoreaction in the first photoresist layer is emitted, to thereby form an intermediate conductive film 5. Next, the intermediate conductive film is patterned. Thereafter, a second photoresist layer 6 is formed on an exposed upper surface of the first photoresist layer after the intermediate conductive film is removed, and on an upper surface of the intermediate conductive film remaining after patterning. The second photoresist layer is divided into a soluble portion 6b and an insoluble portion 6a. Next, the first photoresist layer and the second photoresist layer are developed, and the soluble portions 3b and 6b are removed. Thus, an electroforming mold 101 having a conductive film at the bottom of each stage is obtained.