Formic Acid Dispersion Medium for Low-Temperature Metal Sintering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electroconductive pastes for metal particle sintering face challenges such as corrosion of metal particles, aggregation, and poor storage stability due to the use of organic coatings and the need for reducing gases like formic acid.
Innovation Solution
A dispersion medium containing formic acid and a basic nitrogen-containing compound, specifically a compound represented by Formula (1), is used to suppress corrosion and aggregation of metal particles, allowing for sintering in an inert atmosphere and improving storage stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If formic acid is used as a dispersion medium to supply reducing gas during firing, then sintering can be promoted, but corrosion of metal particles occurs and aggregation is significantly reduced
Solution Approach 1:
A basic compound acts as an intermediary substance that moderates the interaction between formic acid and metal particles. The basic compound controls the release and action of formic acid, preventing direct corrosive contact while maintaining its beneficial reducing gas effect during sintering.
Solution Approach 2:
The invention changes the chemical environment parameters by introducing a basic compound that alters the pH and reactivity conditions. This parameter change transforms formic acid from a corrosive substance into a controlled reducing agent that promotes sintering without damaging metal particles.
2Reliability
If organic coating is applied to metal particles to suppress oxide film formation, then protection is achieved, but the coating process becomes complicated and cost increases
Solution Approach 1:
The invention extracts and removes the complex organic coating step from the process. Instead of applying protective coatings, the solution uses a chemical environment control approach where the basic compound-containing dispersion medium prevents oxide formation through chemical interaction, eliminating the need for separate coating operations.
Solution Approach 2:
The dispersion medium system provides self-protection functionality. The basic compound in the dispersion medium automatically prevents oxide film formation on metal particles during storage and processing, eliminating the need for external protective coatings and their associated complex application processes.
3Ease of manufacture
If high temperature firing is used to remove coating film, then coating removal is achieved, but energy consumption increases and process complexity increases
Solution Approach 1:
The invention extracts and eliminates the high-temperature firing step entirely. By using a basic compound-containing dispersion medium, the organic substances are prevented from forming stable oxide coatings, allowing for low-temperature processing that removes the need for energy-intensive high-temperature firing operations.
4Productivity
If reducing gas such as formic acid is introduced to promote sintering, then sintering is enhanced, but the atmosphere becomes corrosive and storage stability decreases
Solution Approach 1:
The basic compound serves as a mediator that enables controlled interaction between formic acid and the metal particle environment. It facilitates sintering promotion through controlled reducing gas generation while preventing uncontrolled corrosion and maintaining storage stability by regulating the chemical reactivity.
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 proposed solution enables the production of electroconductive pastes that yield sintered bodies with good electroconductivity and bonding strength, even without a reducing atmosphere, and with excellent storage stability and low organic residue.
Implementation Method 1
formic acid volatilizes in a high temperature range of 100° C. or higher
Implementation Method 2
a mixture containing a basic compound and formic acid in a specific molar ratio is used as a dispersion medium in an electroconductive paste, corrosion of metal particles due to formic acid is suppressed
Implementation Method 3
Dispersion medium for metal particle sintering
Data Source
AI summary
Provided are a dispersion medium for metal particle sintering that gives an electroconductive paste whereby metal particles are satisfactorily sintered at a low temperature even when not in a reducing atmosphere, and an electroconductive paste in which the dispersion medium is used. The dispersion medium for metal particle sintering according to an embodiment of the present disclosure contains formic acid and a basic compound, the basic compound being a nitrogen-containing compound represented by Formula (1), and a molar ratio (basic group/formic acid) of basic groups included in the basic compound to formic acid being from 0.50 to 1.20. [Formula 1] In Formula (1): Ra to Rc are the same or different and each represent a hydrogen atom or a hydrocarbon group that may have a substituent; the double line including a dashed line represents a single bond or a double bond, with Rc being absent in the case of a double bond; and any two of Ra to Rc may bond with each other and form a ring together with the adjacent nitrogen atom.