Low-Melting Silver Solder Alloy for PCD Joint Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-temperature soldering processes used in hard soldering are detrimental to temperature-sensitive materials like polycrystalline diamond (PCD), as they require temperatures above 650°C, which can damage these materials, while also being unfavorable for achieving adequate shear strength in soldered joints.
Innovation Solution
A solder alloy with a composition of at least 35% to 62% silver, 10% to 30% copper, 10% to 26% zinc, and the remaining fraction comprising tin, gallium, manganese, or indium, offering a low melting temperature range of 545°C to 620°C, allowing for soldering at lower temperatures without damaging PCD and achieving shear strengths above 1,500 Newton or 110 MPa.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high temperatures (above 650°C) are used in hard soldering to ensure adequate shear strength of soldered joints, then the shear strength is improved, but temperature-sensitive materials like polycrystalline diamond (PCD) suffer or are damaged
Solution Approach 1:
The patent changes the chemical composition parameters of the solder alloy by incorporating specific elements (In, Ga, Mn, Ni) in controlled amounts to modify the melting point and solidification characteristics, enabling soldering at lower temperatures while maintaining joint strength
Solution Approach 2:
The patent creates a composite solder alloy system combining Ag, Cu, Zn with minor additions of In, Ga, Mn, and Ni to achieve synergistic effects that lower melting temperature while preserving or enhancing mechanical properties of the soldered joint
2Strength
If traditional silver-based solder alloys are used to achieve high shear strength, then the shear strength is improved, but the melting temperature becomes too high for temperature-sensitive materials
Solution Approach 1:
The patent systematically adjusts compositional parameters by limiting Ag to 35-62% and Cu to 10-30%, while adding specific amounts of In (0.1-10%), Ga (0.1-10%), Mn (0.1-10%), and Ni (0.1-10%) to achieve the optimal balance between melting point and shear strength
Solution Approach 2:
The patent utilizes phase transition characteristics of the multi-element alloy system, where the addition of In, Ga, Mn, and Ni creates eutectic compositions that lower the melting point while maintaining solid-state strength through controlled phase formation during solidification
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 solder alloy enables soldering of temperature-sensitive materials like PCD at lower temperatures, reducing the risk of damage while maintaining high shear strengths, making it suitable for various material compositions and easy to roll with low brittleness.
Implementation Method 1
the solder alloy has a comparatively low melting temperature, in particular in the range from 545° C. to at most 620° C.
Data Source
AI summary
The invention relates to a solder alloy comprisinga mass fraction from at least 35% to at most 62% of silver,a mass fraction from at least 10% to at most 30% of copper,a mass fraction from at least 10% to at most 26% of zinc, whereinthe remaining mass fractions to 100%, except for unavoidable impurities, comprise at least one element selected from a group consisting of tin, gallium, manganese, nickel, and indium.