Thick Film Paste Metallization for High Temperature Gas Sensors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing thick film pastes for sensor devices, particularly high temperature gas sensors, face issues with surface defects, weldability, and service life due to poor topography and material properties of metallizations.

Innovation Solution

A thick film paste comprising particulate platinum alloy, specific metal compounds like NiO, RuO2, and TiO2, and an organic vehicle, which improves metallization properties by reducing defects and enhancing weldability and service life through a pyrolysis process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional thick film paste is used for metallization, then the production process is simple, but the metallization exhibits surface defects and poor topography

Engineering Contradiction:
Improvemetallization topographyVSAvoidpaste composition
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining particulate platinum alloy with specific metal oxides (NiO, RuO2, TiO2, etc.) and organic vehicle to create a thick film paste that produces metallization with improved topography and reduced surface defects. The composite composition enables better flow and filling properties during firing, resolving the contradiction between manufacturing precision and device complexity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the chemical composition parameters of the thick film paste by incorporating specific metal compounds that form metal oxides during firing. This parameter change in the paste formulation improves the metallization topography and reduces surface defects while maintaining a manageable paste composition structure.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If conventional metallization material is used, then the material composition is simple, but the weldability is poor

Engineering Contradiction:
ImproveweldabilityVSAvoidmetal compound content
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The patent uses composite materials comprising particulate platinum alloy combined with specific metal oxides (NiO, RuO2, TiO2, and others) in defined proportions. This composite structure enhances the weldability of the metallization by improving its physical and chemical properties, while the metal compound content is controlled to achieve the desired weldability without excessive complexity.

Inventive Principle:
Principle #40Composite materials

3Duration of action of stationary object

If conventional thick film paste is used, then the production cost is low, but the service life is reduced

Engineering Contradiction:
Improveservice lifeVSAvoidmetal compound content
Core Design Contradiction:
Duration of action of stationary objectVSQuantity of substance

Solution Approach 1:

The patent employs composite materials with particulate platinum alloy and specific metal oxides (NiO, RuO2, TiO2, etc.) that enhance the durability and service life of the metallization. The controlled inclusion of metal compounds improves the structural integrity and resistance to degradation at high temperatures, extending service life while maintaining cost-effectiveness through optimized composition.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the chemical composition parameters by incorporating specific metal compounds that form stable metal oxides during firing. This parameter change in the paste formulation enhances the service life of the metallization by improving its thermal stability and resistance to degradation, while the metal compound content is optimized to balance performance and cost.

Inventive Principle:
Principle #35Parameter changes

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 paste produces metallizations with improved smoothness, reduced defects, enhanced weldability, and extended service life, making it suitable for high temperature gas sensors.

Implementation Method 1

U.S. Pat. No. 6,165,247 discloses a pyrolysis method for the production of platinum metal, platinum alloy or platinum composite particles

Methodology Applied
Scientific EffectPyrolysis: Pyrolysis

Implementation Method 2

the at least one metal compound is selected from the group consisting of in each case particulate NiO, SiO2, RuO2, Rh2O3, IrO2, Cu2O, CuO, TiO2, ZrO2, PbO, SnO2, CeO2, Al2O3, MgO, MnO2 and MoO2, and metal compounds capable of forming a metal oxide on firing

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentUS10190198B2Thick film paste and use thereof
Publication Date: 2019.01.29 DU PONT CHINA LTD

AI summary

A thick film paste comprising at least one particulate platinum (alloy), at least one metal compound, and an organic vehicle, wherein the at least one metal compound is selected from the group consisting of in each case particulate NiO, SiO2, RuO2, Rh2O3, IrO2, Cu2O, CuO, TiO2, ZrO2, PbO, SnO2, CeO2, Al2O3, MgO, MnO2 and MoO2, and metal compounds capable of forming a metal oxide on firing, the metal oxide being selected from the group consisting of NiO, SiO2, RuO2, Rh2O3, IrO2, Cu2O, CuO, TiO2, ZrO2, PbO, SnO2, CeO2, Al2O3, MgO, MnO2 and MoO2.