Composite Watch Part Manufacturing with Protective Coating

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In the manufacturing of watch components, the use of fragile materials like silicon requires precise and protective masking during lapping operations to prevent damage, which can be cumbersome and interfere with achieving a good quality of flush between metal parts and the structure, leading to inefficiencies and potential damage to the material.

Innovation Solution

A process involving the formation of a non-conductive coating with a hardness of at least 80% of the abrasive material on the structure, allowing for efficient and precise abrasion without the need for protective masks, as the coating protects the underlying material and facilitates smooth surface finishing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If masks are used during lapping to protect fragile materials, then the structure is protected from damage, but the lapping operation becomes more complex and time-consuming

Engineering Contradiction:
Improveprotection of fragile materialVSAvoidmasking operation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A protective coating is applied to the structure before the electro-forming and lapping operations. This preliminary protective layer eliminates the need for masks during lapping, as the coating itself provides the necessary protection while allowing the abrasive to work on the metal parts.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The protective coating acts as an intermediary layer between the abrasive and the fragile structure. It is sufficiently hard to protect the underlying material from damage, yet it can be selectively removed or is thin enough to allow the lapping operation to proceed effectively on the metal parts.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If masks are used during lapping, then the structure is protected, but the masks wear out and require frequent replacement

Engineering Contradiction:
Improveprotection of fragile materialVSAvoidmask wear
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

Instead of using expensive metal masks that wear out, the invention employs a disposable protective coating that is applied directly to the structure. This coating is consumed during the lapping process, eliminating the need for mask replacement while protecting the underlying material.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The structure is given a composite nature by applying a protective coating layer over the base material. This composite structure combines the fragility protection of the coating with the workability needed for the lapping operation, eliminating the need for separate masks.

Inventive Principle:
Principle #40Composite materials

3Reliability

If masks are used during lapping, then protection is provided, but the quality of flush between metal parts and structure deteriorates

Engineering Contradiction:
Improveprotection of fragile materialVSAvoidquality of flush
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The protective function is extracted from the masking operation and integrated directly into the structure through a protective coating. This eliminates the interference that masks create during lapping, allowing the abrasive to work freely and achieve a high-quality flush between the metal parts and the structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The protective function and the structure are merged by applying a coating directly to the structure. This unified approach eliminates the separate mask element that interferes with the lapping process, enabling the abrasive to simultaneously protect the structure and achieve precise flushing of the metal parts.

Inventive Principle:
Principle #5Merging (Combining)

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 method simplifies and enhances the lapping process, ensuring precise and efficient surface flushes between metal parts and the structure, improving the quality of the composite part while protecting the fragile materials, and facilitating balanced operations by defining the metal quantity accurately.

Implementation Method 1

the coating or said at least one of the coatings has a hardness, expressed in pascals, equal to at least 80% of the hardness of the abrasive material

Methodology Applied
Scientific EffectHardness:

Implementation Method 2

the coating or at least one of the coatings being made of a non-conductive material or being coated with a non-conductive sacrificial layer in order to prevent the second material from also forming during the electro-forming

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 3

abrading at least an exposed part of the second material by means of an abrasive material

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP2502877B1Method for manufacturing a composite part, notably for a clock movement
Publication Date: 2013.10.02 PATEK PHILIPPE SA
  • EP2502877B1 patent drawingFigure 1~2
  • EP2502877B1 patent drawingFigure 3(a)~3(g)

AI summary

The method involves forming a base structure (10) by etching a base material, and realizing a coating (12) on the structure, where the obtained coated structure comprises an outer surface. A metal part (17), different from the base material, is filled in a cavity defined by the coated structure. An exposed portion of the metal part is abraded using an abrasive material of an abrasive tool, where hardness of the coating is expressed in terms of Pascals and equal to 80 percent of hardness of the abrasive material. The base material is silicon, quartz, glass, silicon carbide, alumina, zirconium oxide or ceramic material. The coating is realized in one of the following materials such as diamond, silicon carbide, alumina, tungsten carbide, and silicon nitride. The abrasive material is diamond, silicon carbide, alumina, tungsten carbide or silicon nitride.