Surface-Treated Metal Powder Sintering Delay via Alkaline Coupling
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Solution Overview
Problem
The existing techniques for enhancing the sintering delay property of metal powders in ceramic-conductor composites have a narrow applicable range for coupling agents, limiting their versatility in improving bonding properties.
Innovation Solution
By promoting the self-condensation reaction of coupling agents in an alkaline environment before applying them to metal powders, a more versatile technique is achieved, enhancing the sintering delay property even with coupling agents other than aminosilane, resulting in improved bonding between ceramic and conductor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal powder is surface-treated with aminosilane to improve sintering delay property, then bonding property to ceramic substrate is improved, but the applicable range of coupling agent becomes narrow
Solution Approach 1:
The patent changes the pH parameter of the coupling agent solution from conventional acidic conditions to alkaline conditions (pH 11.5-13.5). This parameter change enables the self-condensation reaction to proceed rapidly, forming a siloxane network structure on the metal powder surface. This approach expands the applicable range of coupling agents beyond aminosilane to include other silane-based coupling agents that can undergo self-condensation in alkaline environments, thereby resolving the contradiction between improving bonding property and expanding adaptability.
Solution Approach 2:
The patent applies preliminary action by pre-treating the coupling agent solution with strong alkali to promote self-condensation reaction before the actual coupling reaction with metal powder. This preliminary treatment creates a pre-formed siloxane network structure that enhances the sintering delay property. By performing this preparatory step, the invention achieves improved bonding property while using a broader range of coupling agents, thus resolving the technical contradiction.
2Reliability
If coupling agent is subjected to coupling reaction after stirring overnight in acidic solution to suppress self-condensation, then coupling reaction with metal powder is achieved, but sintering delay property is not significantly improved
Solution Approach 1:
The patent applies inversion by reversing the conventional approach: instead of suppressing self-condensation in acidic conditions and then performing coupling reaction, the invention promotes self-condensation in alkaline conditions first, and then performs the coupling reaction with metal powder. This inverted sequence of operations leads to significant improvement in sintering delay property while maintaining ease of manufacture through a straightforward two-step process.
Solution Approach 2:
The patent changes the pH parameter from acidic to alkaline (pH 11.5-13.5) to promote self-condensation reaction. This parameter change fundamentally alters the reaction pathway, enabling rapid formation of siloxane networks that provide the desired sintering delay property. The process remains easy to manufacture as it simply requires adjusting the pH and stirring for a specified time before adding metal powder.
3Temperature
If self-condensation reaction of coupling agent is promoted in advance by stirring under strong alkali, then sintering starting temperature increases, but process complexity increases
Solution Approach 1:
The patent uses parameter change by adjusting the pH to a specific range (11.5-13.5) and controlling the stirring time (1-24 hours) to promote self-condensation. This controlled parameter adjustment raises the sintering starting temperature to 500°C or higher, improving sintering delay property. The process complexity is minimized by using a simple aqueous solution system and straightforward stirring operation, avoiding the need for complex equipment or multiple processing steps.
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
This approach significantly increases the sintering starting temperature and enhances the bonding property between ceramic and conductor, leading to improved performance in composite materials like laminated ceramic capacitors.
Implementation Method 1
by expediting the self-condensation reaction of the coupling agent more than ever, even if the metal powder is surface-treated with a coupling agent other than aminosilane, the sintering delay property can be improved
Implementation Method 2
a metal powder surface-treated with at least one coupling agent comprising Si, Ti, Al or Zr, wherein a total adhesion amount of Si, Ti, Al and Zr is 200 to 10,000 μg with respect to 1 g of the surface-treated metal powder
Implementation Method 3
a metal powder surface-treated with at least one coupling agent comprising Si, Ti, Al or Zr
Data Source
AI summary
There is provided a more versatile technique that is useful for enhancing the sintering delay property of a metal powder. A metal powder surface-treated with at least one coupling agent comprising Si, Ti, Al or Zr, wherein a total adhesion amount of Si, Ti, Al and Zr is 200 to 10,000 μg with respect to 1 g of the surface-treated metal powder, wherein a 1% by mass aqueous solution of the coupling agent indicates a pH of 7 or less, and wherein a sintering starting temperature is 500° C. or higher.