Mixed Solvents in Multilayer Ceramic Capacitors (MLCC) Electronic Paste and Their Effects on the Properties of Organic Vehicle.

Ruolong Gan,Liying Qian,Jun Huang,Junrong Li,Xiuhua Cao

doi:10.3390/polym14040685

Abstract

The copper end paste used in multilayer ceramic capacitors sintered in nitrogen atmosphere leads to carbon residues of organic vehicles, which leads to a reduction in electrode conductivity and high scrap rate. With an attempt to leave no residue in the sintering, the compatibility of solvents and thickeners should be improved because it has an important influence on the hierarchical volatilization and carbon residue of organic vehicles. In this work, the volatility of different solvents was compared, and several solvents were mixed in a definite proportion to prepare an organic vehicle with polyacrylate resins. The hierarchical volatility and solubility parameters of mixed solvents were effectively adjusted by changing proportions of different components. The thermogravimetric curves of resins and organic vehicles were measured by thermogravimetric analyzer, and the effect of solubility parameter on the dissolvability of resins in the solvent and the residual of organic vehicles were studied. Results showed that the hierarchical volatilization of solvents can be obtained by mixing different solvents; the intrinsic viscosity of the organic vehicle is higher, and the thermal decomposition residue of polyacrylate resins is lower when the solubility parameters of mixed solvents and polyacrylate resins are closer. The low residual sintering of organic vehicles can be achieved by using a mixed solvent with hierarchical volatility and approximate solubility parameters as resins.

Highlights

As one of the three basic components, the multilayer ceramic capacitor (MLCC) has the advantages of small size, high frequency, and low cost compared with other components; MLCC is widely used in various electronic products and is gradually replacing traditional aluminum electrolytic capacitors, which is one of the most widely used capacitors
Polyacrylate resin is commonly used as the thickener in the organic carrier, and the sintering residue of the organic vehicle mainly depends on the thermal degradation of the polyacrylate resin thickener in the solvent
The volatilization characteristics of organic vehicles are closely related to the manufacturing process of thick-film electronic components, which play an important role in the printability, drying, and sintering process of electronic pastes [11]

Summary

Introduction

As one of the three basic components, the multilayer ceramic capacitor (MLCC) has the advantages of small size, high frequency, and low cost compared with other components; MLCC is widely used in various electronic products and is gradually replacing traditional aluminum electrolytic capacitors, which is one of the most widely used capacitors. Copper end electronic paste is composed of three main components: conductive phase (copper), bonding phase (glass or oxide crystals), and organic vehicle. Carbon residue caused by sintering Cu end slurry in a nitrogen atmosphere poses a great challenge to the selection of the organic vehicle composition of base metal inner electrode multilayer ceramic capacitors (BME-MLCC) [3]. The residual rate of thickener in organic vehicles is the key factor to determine the conductivity of electrodes [4]. There are copious studies on the effects of sintering atmosphere, temperature, rate, and time on electroconductibility [5–10], but the effect of thermal degradation characteristics of a thickener on carbon residue is still not clear, and the thickener is the main component of the organic vehicle that applied in MLCC. It is of practical significance to develop methods to select a mixed solvent with hierarchical volatility and to prepare organic vehicles with extremely low residue on the basis of the relationship between the mutual solubility of mixed solvents and thickeners

Methods

Results

Conclusion