Screen printable epoxy/BaTiO₃ embedded capacitor pastes with high dielectric constant for organic substrate applications

Abstract

In this article, embedded capacitor pastes (ECPs) with various BaTiO 3 (BTO) powder contents were formulated and screen-printed on PCBs to fabricate capacitors. The material properties of the ECPs that included their rheology, curing behavior, and dielectric constant were investigated. Embedded capacitors were fabricated for reliability tests related to the thermal cycling and high temperature and humidity potential of optimized ECPs. Additionally, changes in the dielectric properties were discussed. ECPs were formulated with various powder contents from 0 to 70 vol %. ECP resin was cured at temperatures ranging from 130 to 2208C. All ECPs had the viscosities below 30 Pa Á s at a shear rate of 100 s À1 to be easily screen-printable. The dielectric constant of the cured ECPs increased to 60 at 70 vol %, and the dielectric loss was approximately 0.023 for all ECPs regardless of BTO volume content. For the reliability test, ECPs with 50, 60, and 70 vol % BTO powder contents were selected and embedded capacitors were fabricated. After a thermal cycling test with a temperature range from À55 to 1258C for 1000 cycles, capacitance decreased by approximately 5 $ 10%, but the dielectric loss did not change. After a 858C/ 85RH% test for 1000 h, the capacitance and dielectric loss increased by nearly 20%. Cyanoresin (CRS) was used to form the high dielectric polymer/ceramic composite material. The newly formulated resin system had a dielectric constant that is double that of a conventional epoxy resin system. Additionally, the dielectric constant of the polymer/ceramic composite material increased 50% at 50 vol %.

Temperature and voltage aging effects on electrical conduction mechanism in epoxy-BaTiO3 composite dielectric used in embedded capacitors

“…Models for calculating the dielectric constant of a polymer-ceramic composite have been reviewed by Yoon et al [4]. A commonly used model is Lichtenecker's model [5] which is expressed as:…”

Dielectric properties of BaTiO3/epoxy composites by lamination process for embedded capacitor application

“…With development of electronic industry, miniaturization and speeding of electronic component are demanded, especially for passive component [3]. However, conventional discrete components need to be mounted onto a printed circuit board (PCB) or interconnected substrate, which cause high parasitic characteristic, low reliability and large area requirements [4][5][6][7]. These problems prevent the development of electronic products.…”

Reliability of Embedded Planar Capacitors With Epoxy–$\hbox{BaTiO}_{3}$ Composite Dielectric During Temperature–Humidity–Bias Tests

“…Various models for the effective dielectric constant of polymer-ceramic composites have been reviewed by Yoon et al [8]. The common models that describe the dielectric constant of polymer-ceramic composites with zero to three connectivities (particles dispersed and not connected to each other in a continuous matrix) are the Lichtenecker [9], Maxwell [10], and Jayasundere-Smith models [11].…”