Embedded Capacitor Materials Research Articles

Gold-Nanoparticle-Deposited TiO2 Nanorod/Poly(Vinylidene Fluoride) Composites with Enhanced Dielectric Performance.

Flexible dielectric polymer composites have been of great interest as embedded capacitor materials in the electronic industry. However, a polymer composite has a low relative dielectric permittivity (ε′ < 100), while its dielectric loss tangent is generally large (tanδ > 0.1). In this study, we fabricate a novel, high-permittivity polymer nanocomposite system with a low tanδ. The nanocomposite system comprises poly(vinylidene fluoride) (PVDF) co-filled with Au nanoparticles and semiconducting TiO2 nanorods (TNRs) that contain Ti3+ ions. To homogeneously disperse the conductive Au phase, the TNR surface was decorated with Au-NPs ~10–20 nm in size (Au-TNRs) using a modified Turkevich method. The polar β-PVDF phase was enhanced by the incorporation of the Au nanoparticles, partially contributing to the enhanced ε′ value. The introduction of the Au-TNRs in the PVDF matrix provided three-phase Au-TNR/PVDF nanocomposites with excellent dielectric properties (i.e., high ε′ ≈ 157 and low tanδ ≈ 0.05 at 1.8 vol% of Au and 47.4 vol% of TNRs). The ε′ of the three-phase Au-TNR/PVDF composite is ~2.4-times higher than that of the two-phase TNR/PVDF composite, clearly highlighting the primary contribution of the Au nanoparticles at similar filler loadings. The volume fraction dependence of ε′ is in close agreement with the effective medium percolation theory model. The significant enhancement in ε′ was primarily caused by interfacial polarization at the PVDF–conducting Au nanoparticle and PVDF–semiconducting TNR interfaces, as well as by the induced β-PVDF phase. A low tanδ was achieved due to the inhibited conducting pathway formed by direct Au nanoparticle contact.

Highly enhanced frequency- and temperature-stability permittivity of three-phase poly(vinylidene-fluoride) nanocomposites with retaining low loss tangent and high permittivity

Although ceramic/polymer composites have been of great interest as embedded capacitor materials, the composites have a low dielectric permittivity (ε′ ≪ 100) and very large dissipation factor (tanδ ≫ 0.1). In this work, the hybrid particles of silver nanoparticles deposited on BaTiO3 nanoparticles (nAg-nBT) have been used as a filler to enhance the ε′ response in a poly(vinylidene-fluoride) (PVDF) polymer with retaining low tanδ. Residual isolated particles of nAg (i-nAg) and nBT (i-nBT) are the key factors for enhancing the dielectric properties. Significantly increased ε′ ~ 247 (at 103 Hz) with tanδ ~ 0.038 is obtained. The ε′ value is slightly dependent on frequency and temperature over wide ranges. A linear increase in ε′ of the composites at low volume fractions of filler (fAg+nBT < 0.29) is caused by a high ε′ value of nBT particles. An abrupt change in ε′ is observed in the composites at fnAg+nBT > 0.29, which is attributed to a shorten interparticle distance between filler particles, giving rise to strong interfacial polarization. The dielectric behavior can be well described by the effective medium percolation theory (EMPT) model. The discrete deposition of nAg observed in the nAg-nBT and uniform distribution of i-nAg in the PVDF matrix, which is dispersed by nAg-nBT and i-nBT particles, can effectively prevent the formation of the conduction pathways. The obtained low tanδ over the temperature range of 30-140 °C is explained by these two reasons. This research provides a new important concept for the material development of dielectric polymer matrix composites..

Influences of filler dispersity in epoxy resin on the electrical and mechanical performances of embedded capacitance materials

Except for the intrinsic dielectric property of the dielectric filler, its dispersity in polymer matrix also has a big impact on the electrical and mechanical performances of an embedded capacitance material (ECM). Various dielectric fillers are investigated to find the influences of the type and size on the anti-sedimentation and viscosity decreasing properties of the prepared suspensions. The 0.3 µm barium titanate (BaTiO3) synthesized by hydrothermal method shows the optimal effects in preparing dielectric suspension. And the fabricated ECM show the highest electrical and mechanical performances. Embedded capacitors with different sizes are further processed with low changing ratios under 10%. Reliability tests are also conducted to verify the applicability of the ECM in electronic products. This work shows the importance of the well dispersity of dielectric filler in polymer matrix and provides an efficient method for selecting dielectric fillers suitable for ECM fabrication.

High‐Permittivity Composites Thin Films for High‐Energy Storage Capacitor Application Using the Nonvacuum Method

ABSTRACTTo investigate a new embedded capacitor material with high capacitance value, the high dielectric constant (Ba0.8Sr0.2)(Ti0.9Zr0.1)O3 ceramic was ground into nanoscale powder (nano‐BSTZ, the average particle size was approximately 73 nm). Different nano‐BSTZ contents were mixed with polyvinylidene fluoride (PVDF) to form the PVDF/nano‐BSTZ composites. The PVDF/nano‐BSTZ composite films were formed by using the nonvacuum screen printing method on indium tin oxide (ITO) glass, and their thickness was approximately 2 μm. As the nano‐BSTZ content increased from 10 to 50 wt%, the specific capacitance of the PVDF/nano‐BSTZ composite films really increased. Three different mixing rules were used to predict the effective dielectric constants of the PVDF/nano‐BSTZ composite films, and the Bruggeman's effective medium approximation and the Lichtenecker logarithmic mixing rules fitted the measured results. For the printed PVDF/nano‐BSTZ composite films, the dielectric constants also decreased with increasing measured frequency and the loss tangents were all less than 5%.

Reduced Temperature Coefficient of Capacitance (TCC) of Embedded Capacitor Films (ECFs) for Organic Substrates using SrTiO3 and Multifunctional Epoxy

Epoxy/ceramic composites have attracted great interest as embedded capacitor materials, mainly due to the process compatibility of epoxy with printed circuit boards (PCBs). However, one of the potential problems of epoxy/ceramic composites is the temperature dependence of their dielectric properties. This study focuses mainly on reducing the temperature coefficient of capacitance (TCC) of epoxy/ceramic composites using multifunctional epoxy and SrTiO3 powder. The TCC of an epoxy/ceramic composite mainly depends on the properties of its epoxy and ceramic powder. Using multifunctional epoxy, the epoxy resin showed two glass-transition temperatures, resulting in a lower dimensional change after the first glass-transition temperature. Additionally, the TCC of epoxy/SrTiO3 ECFs can be decreased by increasing the SrTiO3 powder content. As a result, reduced TCC of epoxy/ceramic composite capacitors using a multifunctional epoxy and SrTiO3 powder was successfully demonstrated for embedded capacitors in organic substrates.

Dielectric Properties of Polymer-ceramic Composites for Embedded Capacitors

Ceramic-polymer composites have been investigated for their suitability as embedded capacitor materials because they combine the processing ability of polymers with the desired dielectric properties of ceramics. This paper discusses the dielectric properties of the ceramic (<TEX>$BaTiO_3$</TEX>)-polymer (Epoxy) composition as a function of ceramic particle size at a ceramic loading of 40 vol%. The dielectric constant of these ceramic-polymer composites increases as the powder size decreases. Results show that ceramic-polymer composites have a high dielectric constant associated with the <TEX>$BaTiO_3$</TEX> powder with a 200 nm particle size, high insulation resistance, high breakdown voltage (> 22 KV/mm), and low dielectric loss (0.018-0.024) at 1 MHz.

Effects of ${\hbox{CNT/BaTiO}}_{3}$ Composite Particles Prepared by Mechanical Process on Dielectric Properties of Epoxy Hybrid Films

A new type of composite filler mechanically treated with multi-walled carbon nanotubes (MWNTs) and (BT) particles was prepared to produce higher dielectric properties in the composite. The hybrid film fabricated by incorporating these composite fillers in an epoxy matrix had a high dielectric constant and similar dielectric loss as compared to the composite which contained neat BT particles. The dielectric properties of these hybrid films were found to be dependent on both the content of MWNTs and mechanical processing time. Results suggest that this novel hybrid film composed of the composite filler and the epoxy matrix can be used for embedded capacitor material.

A Study on Dielectric Constants of ${\rm Epoxy/SrTiO}_{3}$ Composite for Embedded Capacitor Films (ECFs)

Epoxy/BaTiO3 composites have been of great interest as embedded capacitor materials, mainly due to high dielectric constant of ceramic powders, and good process compatibility of epoxy with printed circuit boards (PCBs). However, one of the potential problems of epoxy/BaTiO3 composite is the dielectric relaxation at gigahertz range. In this paper, epoxy/SrTiO3 composite embedded capacitor films (ECFs) were fabricated for high-frequency applications. Dielectric constants of epoxy/SrTiO3 composite embedded capacitor films with various SrTiO3 particles loading for three different commercial SrTiO3 powders were measured, and experimental data were fitted to the Lichtenecker equation for the prediction of the effective dielectric constant of SrTiO3 powders in epoxy/ SrTiO3 composite ECFs. Using a rectangular cavity resonator method, dielectric constants of epoxy/SrTiO3 composite ECFs were measured at gigahertz range (1-10 GHz). At gigahertz frequencies, dielectric constants of epoxy/SrTiO3 composite ECFs were nearly constant. In contrast, epoxy/BaTiO3 composite ECFs showed decrease of dielectric constants above 5 GHz. Therefore, it is concluded that epoxy/SrTiO3 composite ECFs can be more effectively to be applied for high-frequency applications.

Polymer-ceramic nanocomposites based on new concepts for embedded capacitor

Polymer-ceramic nanocomposites based on new concepts were developed for embedded capacitor applications. The dielectric constant was above 80 at 1 MHz and the specific capacitance was successfully achieved 8 nF/cm 2. By use of this nanocomposites, multilayer printed wiring boards with embedded passive components were fabricated for prototypes. The following technologies would be reported in this conference. Firstly, based on the investigation of barium titanate (BaTiO 3) crystallites, various particles with the sizes from 17 to 100 nm were prepared by the two-step thermal decomposition method from barium titanyl oxalate (BaTiO(C 2O 4) 2·4H 2O). It was clarified that BaTiO 3 particles with a size of around 70 nm exhibited a maximum dielectric constant of over 15,000. Secondary, the BaTiO 3 surface modification based on a new concept was applied to improve the affinity between BaTiO 3 particles and polymer matrix. Thirdly, the blend polymer of an aromatic polyamide (PA) and an aromatic bismaleimide (BMI) was employed as the matrix from a view-point of both the processability during fabricating the substrates with embedded passive components and the thermal stability during assembling LSI chips. Finally, these technologies were combined and optimized for embedded capacitor materials.

Polymer-Ceramic Nanocomposites Based on New Concepts for Embedded Capacitor

A rapid growth of mixed-signal integrated circuits is driving the needs of multifunction and miniaturization of the component in electronics applications. Polymer-ceramic composites have been of great interest as embedded capacitor materials because they enabled companies to combine the processability of polymers with the high dielectric constant of ceramics. Polymer-ceramic nanocomposites based on new concepts were developed for embedded capacitor applications. The dielectric constant was above 80 at 1 MHz and the specific capacitance was successfully achieved 8 nF/cm2. By use of this nanocomposites, multilayer printed wiring boards with embedded passive components were fabricated for prototypes. The following technologies are reported in this paper. Firstly, based on the investigation of barium titanium oxide (BaTiO3) crystallites, various particles with the sizes from 17 nm to 100 nm were prepared by the 2-step thermal decomposition method from barium titanyl oxalate (BaTiO(C2O4)2·4H2O). It was clarified that BaTiO3 particles with a size of around 70 nm exhibited a maximum dielectric constant of over 15,000 by FEM analysis from the measured dielectric constants of BaTiO3 suspensions. Secondary, the BaTiO3 surface modification based on a new concept was applied to improve the affinity between BaTiO3 particles and polymer matrix. Thirdly, the blend polymer of an aromatic polyamide (PA) and an aromatic bismaleimide (BMI) was employed as the matrix from a view-point of both the processabilty during fabricating the substrates with embedded passive components and the thermal stability during assembling LSI chips. Finally, these technologies were combined and optimized for embedded capacitor materials.

Novel polymer-ceramic nanocomposite based on new concepts for embedded capacitor application (I)

A rapid growth of mixed-signal integrated circuits is driving the needs of multifunction and miniaturization of the component in electronics applications. Polymer-ceramic composites have been of great interest as embedded capacitor materials because they enabled companies to combine the processability of polymers with the high dielectric constant of ceramics. This paper presents the preparations and performance characterizations of novel polymer-ceramic nanocomposites based on new concepts for embedded capacitor application. First, metal particle nickel-filled nanocomposite with high dielectric constant was evaluated as a candidate for embedded capacitors. Two types of nickel particles were selected with the size of 400 and 150nm, respectively. With proper filler loading and highly dispersed, a high dielectric constant of over 90 was observed with a filler loading ratio of 60-vol%. Second, the surface modification of a barium titanate (BTO) particle was also attempted in nanocomposite. Phthalocyanine-coated BTO (Pc-coated BTO) was selected as filler to prepare the composite. Its dielectric constant was observed as over 80 at 1MHz, which was much higher than that of composite derived from commercial BTO. Last, in order to improve the processability of the nanocomposite, 4, 4'-diphenylmethane bismaleimide (BMI) was selected as a matrix polymer by the combination with polyamide (PA). Higher dielectric constant nanocomposite derived from PA/BMI and Pc-coat BTO was obtained, and its potential application towards embedded capacitors was also evaluated.

Design considerations for thin‐film embedded resistor and capacitor technologies

Embedded passives technologies can provide benefits of size, performance, cost, and reliability to high density, high‐speed designs. A number of embedded passive technology solutions are available to the designer. Based on our experience with Rohm and Haas's thin‐film, high‐ohmic, InSiteTM embedded resistor materials (500 and 1000 Ω/sq), this paper provides some guidelines for selecting the appropriate embedded resistor technology and implementing it at a board fabricator. The design of embedded resistors, and the trade‐offs between resistor size, tolerance, and capability of board fabrication processes, are analyzed in detail. This paper also discusses selection of the appropriate embedded capacitor technology and introduces some initial results on Rohm and Haas's thin‐film, high‐Dk, InSite embedded capacitor material (200 nF/cm2).

Comparison of theoretical predictions and experimental values of the dielectric constant of epoxy/BaTiO3 composite embedded capacitor films

Polymer/ceramic composites are the most promising embedded capacitor material for organic substrates application. Predicting the effective dielectric constant of polymer/ceramic composites is very important for design of composite materials. In this paper, we measured the dielectric constant of epoxy/BaTiO3 composite embedded capacitor films with various BaTiO3 particles loading for 5 different sizes BaTiO3 powders. Experimental data were fitted to several theoretical equations to find the equation useful for the prediction of the effective dielectric constant of polymer/ceramic composites and also to estimate the dielectric constant of BaTiO3 powders. The Lichtenecker equation and the Jayasundere-Smith equation were useful for the prediction of the effective dielectric constant of epoxy/BaTiO3 composites. And calculated dielectric constants of the BaTiO3 powders were in the range of 100 to 600, which were lower than the dielectric constant of BaTiO3 bulk ceramics probably due to the presence of voids or pores.

Comparison of theoretical predictions and experimental values of the dielectric constant of epoxy/BaTiO3 composite embedded capacitor films

Polymer/ceramic composites are the most promising embedded capacitor material for organic substrates application. Predicting the effective dielectric constant of polymer/ceramic composites is very important for design of composite materials. In this paper, we measured the dielectric constant of epoxy/BaTiO3 composite embedded capacitor films with various BaTiO3 particles loading for 5 different sizes BaTiO3 powders. Experimental data were fitted to several theoretical equations to find the equation useful for the prediction of the effective dielectric constant of polymer/ceramic composites and also to estimate the dielectric constant of BaTiO3 powders. The Lichtenecker equation and the Jayasundere-Smith equation were useful for the prediction of the effective dielectric constant of epoxy/BaTiO3 composites. And calculated dielectric constants of the BaTiO3 powders were in the range of 100 to 600, which were lower than the dielectric constant of BaTiO3 bulk ceramics probably due to the presence of voids or pores.

High Dielectric Ceramic Nano Particle and Polymer Composites for Embedded Capacitor

Polymer-ceramic nanocomposites based on new concepts were developed for embedded capacitor applications. The dielectric constant was above 80 at 1 MHz and the specific capacitance was successfully achieved 8 nF/cm2. By use of this nanocomposites, multilayer printed wiring boards with embedded passive components were fabricated for prototypes. High dielectric constant Barium titanate (BaTiO3) beads surface modification based on a new concept was applied to improve the affinity between BaTiO3 particles and polymer matrix. Next, the blend polymer of an aromatic polyamide (PA) and an aromatic bismaleimide (BMI) was employed as the matrix as from a view-point of both the processabilty during fabricating the substrates with embedded passive components and the thermal stability during assembling LSI chips. Finally, these technologies were combined and optimized for embedded capacitor materials.

Material characterization of a high‐dielectric‐constant polymer–ceramic composite for embedded capacitor for RF applications

AbstractEmbedded capacitor technology can improve electrical performance and reduce assembly cost compared with traditional discrete capacitor technology. Polymer–ceramic composites have been of great interest as embedded capacitor materials because they combine the processability of polymers with the desired electrical properties of ceramics. We have developed a novel nanostructure polymer–ceramic composite with a very high dielectric constant (εr ≈ 150, a new record for the highest reported εr value of a nanocomposite) in a previous work. RF applications of embedded capacitors require that the insulating material have a high εr at a high frequency (in the gigahertz range), low leakage current, high breakdown voltage, and high reliability. A set of electrical tests were conducted in this study to characterize the electrical properties of the novel high‐εr polymer–ceramic nanocomposite developed in‐ house. The results show that this material had a fairly high εr in the RF range, low electrical leakage, and high breakdown voltage. An 85°C/85% thermal humidity aging test was been performed, and it showed that this novel high‐K material had good reliability. An embedded capacitor prototype with a capacitance density of 35 nF/cm2 was manufactured with this nanocomposite with spin‐coating technology. This novel nanocomposite can be used for the integral capacitors for RF applications. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2228–2231, 2004

Di-block copolymer surfactant study to optimize filler dispersion in high dielectric constant polymer-ceramic composite

Embedded capacitor technology can improve electrical performance and reduce assembly cost compared with traditional discrete capacitor technology. Polymer-ceramic composites have been of great interest as embedded capacitor material because they combine the processability of polymers with the desired electrical properties of ceramics. Dispersion of ceramic particles is a critical factor to affect the effective dielectric constant of polymer-ceramic composite. Di-block copolymer surfactants have been used to prevent agglomeration of the ceramic particles. It was found that di-block copolymer surfactant could improve the ceramic dispersion better than monomer surfactant. Using di-block copolymer surfactant, higher dielectric constant was achieved at lower ceramic loading level. This high dielectric constant polymer-ceramic composite material has much better mechanical properties and can be used for the integral capacitors in the SOP (system on a package) substrate.

Novel polymer–ceramic nanocomposite based on high dielectric constant epoxy formula for embedded capacitor application

AbstractEmbedded capacitor technology can increase silicon packing efficiency, improve electrical performance, and reduce assembly cost compared with traditional discrete capacitor technology. Developing a suitable material that satisfies electrical, reliability, and processing requirements is one of the major challenges of incorporating capacitors into a printed wiring board (PWB). Polymer–ceramic composites have been of great interest as embedded capacitor material because they combine the processability of polymers with the high dielectric constant of ceramics. A novel nanostructure polymer–ceramic composite with a very high dielectric constant (εr ∼110, a new record for the highest reported εr value of a nanocomposite) was developed in this work. A high dielectric constant is obtained by increasing the dielectric constant of the epoxy matrix (εr &gt;6) and using the combination of lead magnesium niobate–lead titanate (PMN–PT)/BaTiO3 as the ceramic filler. This nanocomposite has a low curing temperature (&lt;200°C); thus, it is multichip‐module laminate (MCM‐L) process‐compatible. An embedded capacitor prototype with a capacitance density of 50 nF/cm2 was manufactured using this nanocomposite and spin‐coating technology. The effect of the composite microstructure on the effective dielectric constant was studied. This novel nanocomposite can be used for integral capacitors in PWBs. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1084–1090, 2002

Material Characterization of High Dielectric Constant Polymer–CeramicComposite for Embedded Capacitor to RF Application

Embedded capacitor technology can improve electrical performance and reduce assembly cost compared with traditional discrete capacitor technology. Polymer–ceramic composites have been of great interest as embedded capacitor material because they combine the processability of polymers with the desired electrical properties of ceramics. A novel nano‐structure polymer–ceramic composite with very high dielectric constant (εr ~ 150 , a new record for the highest reported εr value of nano‐composite) has been developed in our previous work. RF application of embedded capacitors requires that insulating material have high dielectric constant at high frequency (GHz), low leakage current, high breakdown voltage and high reliability. A set of electrical tests have been conducted in this work to characterize the properties of the in house developed novel high dielectric constant polymer–ceramic nano‐composite. Results show that this material has faily high dielectric constant in the RF range, low electrical leakage and high breakdown voltage. 85/85 TH aging test has been performed and it had shown this novel high K material has good reliability. An embedded capacitor prototype with capacitance density of 35 nF/cm2 has been manufactured using this nano‐composite with spinning coating technology. This novel nano‐composite can be used for the integral capacitors in the RF applications.