Conductive Paste Base Metal Surface Area Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conductive pastes used for forming anti-fogging glass and glass antennas on vehicle windows face issues with inferior weather resistance and high resistivity due to rapid oxidation of base metal particles, which decreases wettability and sintered density, leading to increased resistivity and potential erosion from environmental exposure.
Innovation Solution
A conductive paste comprising a noble metal powder and a base metal powder with a specific surface area less than 0.5 m2/g, primarily containing Cu and/or Ni, which slows oxidation and maintains wettability, allowing glass frit to seal voids and achieve favorable weather resistance and moderate resistivity control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If base metal particles rapidly oxidize during firing, then oxygen consumption increases, but wettability of glass frit decreases
Solution Approach 1:
By controlling the specific surface area parameter of base metal particles to 0.05 to 0.45 m²/g, the invention regulates the oxidation rate during firing. This controlled oxidation prevents rapid oxygen consumption while maintaining stable wettability of glass frit, ensuring proper infiltration into voids and formation of a dense conductive film
2Manufacturing precision
If glass frit wettability decreases, then void infiltration is blocked, but weather resistance deteriorates
Solution Approach 1:
The invention changes the specific surface area parameter of base metal particles to control oxidation kinetics. By maintaining specific surface area within 0.05 to 0.45 m²/g, the oxidation rate is slowed sufficiently to preserve glass frit wettability throughout the firing process, enabling complete void infiltration and formation of a weather-resistant sealed structure
3Speed
If base metal particle specific surface area is increased, then oxidation rate increases, but wettability stability decreases
Solution Approach 1:
The invention optimizes the specific surface area parameter of base metal particles to a specific range (0.05 to 0.45 m²/g) that balances oxidation rate and wettability stability. This parameter optimization ensures that oxidation proceeds at a controlled pace, maintaining stable wettability throughout the firing process while achieving complete void infiltration
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 conductive paste provides glass articles with improved weather resistance and controllable resistivity, suitable for applications with voltages ranging from 12 to 48 V, ensuring effective performance in vehicle window applications.
Implementation Method 1
the base metal particles consume oxygen in the conductive film through an oxidation reaction during firing
Implementation Method 2
decreasing the wettability of the glass frit as an oxide
Implementation Method 3
the ingress of the glass frit into the voids is blocked
Implementation Method 4
the paste is fired
Implementation Method 5
the decreased wettability of the glass frit interferes with liquid-phase sintering
Data Source
AI summary
A conductive paste contains at least a conductive powder, glass frit, and an organic vehicle. The conductive powder contains a noble metal powder such as an Ag powder and a base metal powder containing Cu and/or Ni, and the base metal powder has a specific surface area of less than 0.5 m2/g. The content of the base metal powder with respect to the total amount of the conductive powder is, in ratio by weight, 0.1 to 0.3 when the base metal powder contains Cu as its main constituent, 0.1 to 0.2 when the base metal powder contains Ni as its main constituent, and 0.1 to 0.25 when the base metal powder contains a mixed powder of Cu and Ni as its main constituent.