Silver Copper Alloyed Rivet Contact Barrier Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional double-layered rivet contacts experience peeling of the Ag alloy contact material from the base material under high-load conditions, leading to potential short-circuits and equipment failure due to oxide formation at the junction interface.
Innovation Solution
A barrier layer containing an Ag alloy is introduced at the junction interface between the contact material and the base material, inhibiting oxygen diffusion and preventing Cu oxide formation, thereby enhancing the bonding strength and endurance of the rivet contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a double-layered rivet contact structure is used to reduce costs, then the member cost is reduced, but the contact material peels from the base material under high-load conditions
Solution Approach 1:
The rivet contact is divided into three distinct layers: a contact material layer (Ag-based), a barrier layer (Ag alloy with specific composition), and a base material layer (Cu-based). This segmentation allows each layer to perform its specific function - the barrier layer prevents oxygen diffusion while maintaining electrical conductivity, resolving the contradiction between cost reduction and bonding strength.
Solution Approach 2:
The barrier layer acts as an intermediary between the contact material layer and the base material layer. It mediates the interaction by preventing oxygen from reaching the Cu base material while maintaining good bonding with both adjacent layers, thus preventing peeling without requiring the entire structure to be expensive Ag alloy.
2Ease of manufacture
If oxygen diffusion is allowed at the junction interface, then the manufacturing process is simple, but Cu oxide forms causing peeling and contact failure
Solution Approach 1:
The barrier layer is designed to contain elements that have high affinity for oxygen (such as Sn, In, Ni). These elements that could potentially cause oxidation are instead used to create a protective barrier that preferentially binds oxygen, converting the harmful oxidation effect into a beneficial protective function that prevents Cu oxide formation.
Solution Approach 2:
The barrier layer is composed of Ag alloy with specific additions (0.01-10 mass% Sn and/or In, and 0.01-5 mass% Ni) that create a composite material with unique properties: good bonding to both Ag-based and Cu-based materials, electrical conductivity, and resistance to oxygen diffusion. This composite approach solves the contradiction between manufacturing simplicity and oxide prevention.
3Reliability
If the entire contact is made of Ag alloy, then peeling is prevented, but the member cost increases significantly
Solution Approach 1:
Instead of making the entire rivet contact from expensive Ag alloy, the invention applies Ag-based contact material only where it is most needed (the contact surface and near region), while using a Cu-based base material for the bulk structure. The barrier layer with specific Ag alloy composition is applied locally at the junction interface to provide peeling resistance, achieving reliable performance with reduced overall cost.
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 Ag alloy barrier layer effectively suppresses peeling and oxide generation, improving the endurance life of the rivet contact without compromising electrical properties, and is particularly effective when composed of specific Ag alloys with added elements like Cu, Ni, Sn, and In.
Implementation Method 1
a barrier layer containing an Ag alloy is provided at a junction interface between the contact material layer and the base material... inhibiting oxygen diffusion and preventing Cu oxide formation
Data Source
AI summary
The present invention is a rivet contact including a head portion and a foot portion having a smaller width than the head portion, wherein the head portion contains a contact material layer having at least a top containing an Ag-based contact material; the rest of the head portion and the foot portion contain a base material containing Cu or a Cu alloy; and a barrier layer including an Ag alloy is provided at a junction interface between the contact material and the base material. Here, an Ag alloy obtained in such a manner that one or more base metal elements of Sn, In, Cu, Ni, Fe, Co, W, Mo, Zn, Cd, Te, and Bi are added to Ag by 0.03 to 20 mass % is preferably used as the Ag alloy constituting the barrier layer.