Gold-Plated Slip Ring Contact Noise Reduction
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Solution Overview
Problem
Conventional slip ring contacts suffer from high electrical noise due to the smoothness of their surface layers, which affects their electrical behavior and reliability in establishing connections between moving parts.
Innovation Solution
A method involving the galvanic application of a copper layer without brighteners, followed by a nickel and/or nickel-phosphorus layer, and a gold layer, resulting in a rougher surface structure that enhances the electrical properties of the gold-plated slip ring contact, specifically using a potassium-copper cyanide solution for copper plating and optimizing layer thicknesses to achieve increased roughness and reduced noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If brighteners are used in the electroplating bath to produce a smooth copper layer, then the surface finish is improved, but the contact noise increases
Solution Approach 1:
The invention extracts and removes the brighteners from the electroplating bath composition. By taking out the harmful substance (brighteners) that causes excessive smoothness, the process produces a copper layer with controlled roughness that reduces contact noise while maintaining adequate surface finish for electrical contact.
Solution Approach 2:
The invention changes the surface roughness parameter of the copper layer from the conventional smooth finish (Sa/Sq values of 10-50 nm) to a deliberately rougher finish (Sa/Sq values of 200 nm to 1 μm). This parameter change is achieved by modifying the electroplating process to exclude brighteners, thereby transforming the surface characteristics to reduce contact noise.
2Manufacturing precision
If brighteners are used in the electroplating bath, then the copper layer has lower roughness, but the electrical behavior deteriorates
Solution Approach 1:
The invention extracts and removes the brighteners from the electroplating bath composition. By taking out the harmful substance (brighteners) that causes excessive smoothness, the process produces a copper layer with controlled roughness that reduces contact noise while maintaining adequate surface finish for electrical contact.
Solution Approach 2:
The invention changes the surface roughness parameter of the copper layer from the conventional smooth finish (Sa/Sq values of 10-50 nm) to a deliberately rougher finish (Sa/Sq values of 200 nm to 1 μm). This parameter change is achieved by modifying the electroplating process to exclude brighteners, thereby transforming the surface characteristics to reduce contact noise.
3Ease of manufacture
If conventional electroplating with brighteners is used, then the production process is simple, but the contact noise is high
Solution Approach 1:
The invention extracts and removes the brighteners from the electroplating bath composition. By taking out the harmful substance (brighteners) that causes excessive smoothness, the process produces a copper layer with controlled roughness that reduces contact noise while maintaining adequate surface finish for electrical contact.
Solution Approach 2:
The invention changes the surface roughness parameter of the copper layer from the conventional smooth finish (Sa/Sq values of 10-50 nm) to a deliberately rougher finish (Sa/Sq values of 200 nm to 1 μm). This parameter change is achieved by modifying the electroplating process to exclude brighteners, thereby transforming the surface characteristics to reduce contact noise.
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 reduces contact noise by a factor of at least two, as demonstrated by spring wire tests, and improves the overall electrical performance of the gold-plated slip ring contacts by maintaining the increased roughness through multiple layers, enhancing their durability and reliability.
Implementation Method 1
galvanic application of a copper layer to the substrate, galvanic application of a nickel and / or nickel-phosphorus layer to the copper layer, and galvanic application of a gold layer to the nickel and/or nickel-phosphorus layer
Data Source
Figure 1~3
Figure 4
AI summary
Method for producing a gold-plated slip ring contact comprising the following process steps: providing an electrically conductive substrate; electroplating a copper layer (12) onto the substrate; electroplating a nickel and/or nickel-phosphorus layer (14) onto the copper layer (12); and electroplating a gold layer (16) onto the nickel and/or nickel-phosphorus layer (14).In this process, during the electroplating of the copper layer (12) onto the substrate in the electroplating bath used, at least one gloss agent is not used, which is listed as consisting of 3-Carboxy-1-(phenylmethyl)pyridinium chloride sodium salt, cationic polymers with urea groups, 1-(3-Sulfopropyl)-pyridinium betaine, 1-(2-Hydroxy-3-sulfopropyl)-pyridinium betaine, propargyl (3-sulfopropyl) ether sodium salt, sodium saccharin, sodium allyl sulfonate, N,N-Dimethyl-N-(3-cocoamidopropyl)-N-(2-hydroxy-3-sulfopropyl) ammonium betaine, polyamines, 1H-imidazole polymer with (chloromethyl)oxirane, 3-Carboxy-1-(phenylmethyl)pyridinium chloride sodium salt. It consists of 1-Benzyl-3-Sodium carboxy-pyridinium chloride, arsenic trioxide, potassium antimony tartrate, potassium tellurate, alkali arsenite, potassium tellerite, potassium selenocyanate, alkali antimony tartrate, sodium selenite, thallium sulfate and carbon disulfide.