Copper Joining Paste Composition for Printable High-Strength Sinter Bonds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor device manufacturing, copper pastes face challenges in achieving both good printing properties for automated printing and sufficient joining strength, especially when using copper particles, as low particle concentrations can lead to inadequate joining reliability and printing issues.
Innovation Solution
A copper paste with copper particles and dihydroterpineol as the dispersion medium, which improves dispersibility and viscosity, allowing for effective printing and joining, even at high copper particle concentrations, and includes submicro and micro copper particles for enhanced sinterability and adhesiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If copper particle concentration is increased to ensure sufficient joining strength, then joining properties are improved, but printing properties deteriorate due to increased viscosity
Solution Approach 1:
The patent changes the chemical composition parameter of the dispersion medium by selecting dihydroterpineol with specific molecular structure and properties. This parameter change allows the paste to maintain low viscosity even at high copper particle concentrations (85-98% by mass), thereby resolving the contradiction between joining strength and printing properties
Solution Approach 2:
The patent creates a composite paste system consisting of copper particles (including submicro and micro particles) dispersed in dihydroterpineol. This composite structure enables the paste to exhibit both high solid content for strong joining and appropriate rheological properties for good printing performance
2Ease of operation
If copper particle concentration is decreased to improve printing properties, then printing properties are improved, but joining strength becomes insufficient
Solution Approach 1:
By changing the dispersion medium to dihydroterpineol with specific physical and chemical parameters (molecular weight, boiling point, affinity for copper), the paste achieves excellent流动性 at high particle concentrations, eliminating the need to reduce copper content to improve printing
3Ease of operation
If conventional dispersion media are used to reduce viscosity for printing, then printing properties are improved, but dispersibility of copper particles deteriorates
Solution Approach 1:
Dihydroterpineol acts as an intermediary substance that mediates between copper particles and the paste matrix. Its molecular structure provides both copper affinity (improving dispersibility) and appropriate viscosity characteristics (improving printing properties), resolving the contradiction between these two requirements
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 copper paste enables efficient production of joined bodies with improved printing and joining properties, maintaining strength and reliability, particularly suitable for mass production using automated printers like screen printers, under non-pressurization conditions.
Implementation Method 1
a copper paste for joining containing metal particles and a dispersion medium, in which the copper paste for joining contains copper particles as the metal particles, and the copper paste for joining contains dihydroterpineol as the dispersion medium
Implementation Method 2
since dihydroterpineol can increase thixotropy of a paste, both of fluidity during printing and the shape retaining force of the paste after printing are achieved in a high level
Implementation Method 3
a method for manufacturing a joined body which includes a first member, a second member, and a joining portion that joins the first member and the second member
Data Source
Figure 1(a)~1(d)
Figure 2
Figure 3
AI summary
A copper paste for joining contains metal particles and a dispersion medium, in which the copper paste for joining contains copper particles as the metal particles, and the copper paste for joining contains dihydroterpineol as the dispersion medium. A method for manufacturing a joined body is a method for manufacturing a joined body which includes a first member, a second member, and a joining portion that joins the first member and the second member, the method including: a first step of printing the above-described copper paste for joining to at least one joining surface of the first member and the second member to prepare a laminate having a laminate structure in which the first member, the copper paste for joining, and the second member are laminated in this order; and a second step of sintering the copper paste for joining of the laminate.