Conductive Paste for Multi-Layered Ceramic Components
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing conductive pastes used in multi-layered ceramic electronic components, particularly those using terpineol as a solvent, cause the binder in the ceramic green sheet to dissolve, leading to pinholes and cracks, which result in short circuit failures, especially when the sheets are very thin.
Innovation Solution
A conductive paste is developed using a binder with ethyl cellulose having a specific weight average molecular weight ratio and solvents like isobornyl acetate, which prevents the binder from dissolving and maintains suitable viscosity for printing, thereby preventing pinholes and cracks in the ceramic green sheet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If terpineol is used as a solvent in conductive paste, then the paste has good dissolving power for the binder, but the binder in the ceramic green sheet dissolves causing pinholes and cracks
Solution Approach 1:
The patent introduces an intermediary substance (wax) that acts as a barrier between the solvent (terpineol) and the binder in the ceramic green sheet. The wax prevents direct contact between the solvent and binder, thereby preventing dissolution and formation of pinholes/cracks while still allowing the solvent to perform its function of dissolving the conductive paste binder.
Solution Approach 2:
The patent converts the harmful effect of terpineol (dissolving the binder) into a beneficial outcome by adding wax that controls the solvent's action. The same solvent that causes harm is retained and its harmful effect is neutralized by the wax, allowing the manufacturing process to maintain good dissolving power without the negative consequences.
2Volume of moving object
If the ceramic green sheet is made thinner to downsize the component, then the component size is reduced, but the sheet becomes more susceptible to dissolution and short circuit failures
Solution Approach 1:
The patent applies preliminary anti-action by pre-coating the ceramic green sheet with wax before applying the conductive paste. This preliminary protective layer prevents the subsequent solvent from dissolving the binder, thereby preemptively countering the harmful effect that would otherwise occur during the printing process.
3Reliability
If hydrocarbon system solvent is used instead of terpineol, then the binder dissolution is reduced, but the viscosity control becomes difficult
Solution Approach 1:
The patent changes the physical-chemical parameters of the conductive paste by incorporating wax, which modifies the viscosity characteristics. The wax allows the use of terpineol while controlling the paste's viscosity to suitable levels, thereby maintaining ease of manufacture despite the presence of a powerful solvent.
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 solution effectively prevents short circuit failures by maintaining the integrity of the ceramic green sheet, even when very thin, and ensures excellent printability of the electrode layer.
Implementation Method 1
the binder contained in the ceramic green sheet is dissolved by terpineol contained in the conductive paste
Data Source
AI summary
It is an object of the present invention to provide a method for manufacturing a multi-layered unit for a multi-layered ceramic electronic component which can reliably prevent short circuit failure from occurring in a multi-layered ceramic electronic component and form an electrode layer in a desired manner.A method for manufacturing a multi-layered ceramic electronic component includes a step of printing a conductive paste containing a binder containing ethyl cellulose having a weight average molecular weight of MWL and ethyl cellulose having a weight average molecular weight of MWH at a weight ratio of X:(1−X), where MWL, MWH and X are selected so that X*MWL+(1−X)*MWH falls within a range of 145,000 to 215,000 and at least one solvent selected from the group consisting of isobornyl acetate, dihydroterpinyl methyl ether, terpinyl methyl ether, α-terpinyl acetate, I-dihydrocarvyl acetate, I-menthone, I-menthyl acetate, I-perillyl acetate and I-carvyl acetate on a ceramic green sheet containing a butyral system resin as a binder in a predetermined pattern, thereby forming an electrode layer.