Embedded Capacitors in Printed Wiring Board: A Technological Review

This paper reviews the technology of embedded capacitors, which has gained importance with an increase in the operating frequency and a decrease in the supply voltage of electronic circuits. These capacitors have been found to reduce the number of surface-mount capacitors, which can assist in the miniaturization of printed wiring boards. This paper describes various aspects of embedded capacitors, such as electrical performance, available dielectric materials, manufacturing processes, and reliability. Improvement in electrical performance is explained using a cavity model from the theory of microstrip antennas. The advantages and disadvantages of dielectric materials such as polymers, ceramics, polymer–ceramic composites, and polymer–conductive filler composites are discussed. Various manufacturing techniques that can be used for the fabrication of embedded capacitors are also discussed. Embedded capacitors have many advantages, but failure of an embedded capacitor can lead to board failure since these capacitors are not reworkable. The effect of various environmental stress conditions on the reliability of embedded capacitors is reviewed.

[1]  P. Kohl,et al.  Factors influencing the permittivity of polymer/ceramic composites for embedded capacitors , 2000, ECTC 2000.

[2]  J. K. Nelson,et al.  Nanocomposite dielectrics—properties and implications , 2005 .

[3]  K. Paik,et al.  Epoxy/TaTiO/sub 3/ composite films and pastes for high dielectric constant and low tolerance embedded capacitors fabrication in organic substrates , 2004, 4th IEEE International Conference on Polymers and Adhesives in Microelectronics and Photonics, 2004. POLYTRONIC 2004..

[4]  K. Koumoto,et al.  Effect of crystal-axis orientation on dielectric properties of ceramics prepared from fibrous barium titanate , 1994 .

[5]  V. Surganov.  Planarized thin film inductors and capacitors for hybrid integrated circuits made of aluminum and anodic alumina , 1994 .

[6]  Novel polymer-ceramic nanocomposite based on new concepts for embedded capacitor application (I) , 2004, IEEE Transactions on Components and Packaging Technologies.

[7]  Jun Zhang,et al.  Poly(methyl methacrylate)–titania hybrid materials by sol–gel processing , 1997 .

[8]  J. Obrzut,et al.  Dielectric Properties of Polymer/Ferroelectric Ceramic Composites from 100 Hz to 10 GHz , 2001 .

[9]  R. Sodhi,et al.  TiOx interlayer characterization for sol–gel derived Pb(Zr, Ti)O3 thin films on titanium foil , 2002 .

[10]  Barry Kent Gilbert,et al.  High-frequency characterization of power/ground-plane structures , 1999 .

[11]  Ching-ping Wong,et al.  An improved methodology for determining temperature dependent moduli of underfill encapsulants , 2000 .

[12]  Hyungsoo Kim,et al.  A Study on Dielectric Constants of ${\rm Epoxy/SrTiO}_{3}$ Composite for Embedded Capacitor Films (ECFs) , 2007, IEEE Transactions on Advanced Packaging.

[13]  Hiroshi Kishi,et al.  Base-Metal Electrode-Multilayer Ceramic Capacitors: Past, Present and Future Perspectives , 2003 .

[14]  B. Archambeault,et al.  A simple finite-difference frequency-domain (FDFD) algorithm for analysis of switching noise in printed circuit boards and packages , 2003 .

[15]  E. J. Rymaszewski,et al.  Low-temperature fabrication of amorphous BaTiO/sub 3/ thin-film bypass capacitors , 1993, IEEE Electron Device Letters.

[16]  S. L. Swartz,et al.  Topics in electronic ceramics , 1990 .

[17]  M. E. Ryan,et al.  Rheological Behavior of Filled Polymeric Systems II. The Effect of a Bimodal Size Distribution of Particulates , 1988 .

[18]  Mohammed A. Alam,et al.  Prognostics of Failures in Embedded Planar Capacitors using Model-Based and Data-Driven Approaches , 2011 .

[19]  C. Kittel.  Introduction to solid state physics , 1954 .

[20]  K. Moon,et al.  Glass transition and relaxation behavior of epoxy nanocomposites , 2004 .

[21]  Winco K.C. Yung,et al.  Embedded components in printed circuit boards: a processing technology review , 2005 .

[22]  K. Moon,et al.  A novel aluminum-filled composite dielectric for embedded passive applications , 2006, IEEE Transactions on Advanced Packaging.

[23]  Daniel N. Donahoe,et al.  Moisture induced degradation of multilayer ceramic capacitors , 2006, Microelectron. Reliab..

[24]  L. Burton,et al.  Charge Carriers and Time Dependent Currents in BaTiO 3 -Based Ceramic , 1986 .

[25]  Xiaolong Cao,et al.  Preparation and dielectric property of Ag–PVA nano-composite , 2003 .

[26]  W. P. Mason.  Aging of the Properties of Barium Titanate and Related Ferroelectric Ceramics , 1955 .

[27]  Rao Tummala,et al.  Next generation integral passives: materials, processes, and integration of resistors and capacitors on PWB substrates , 2000 .

[28]  R. Tummala,et al.  Epoxy Nanocomposite Capacitors for Application as MCM-L Compatible Integral Passives , 2002 .

[29]  J. Moya,et al.  Experimental evidence of a giant capacitance in insulator-conductor composites at the percolation threshold , 2000 .

[30]  N. Jayasundere,et al.  Dielectric constant for binary piezoelectric 0‐3 composites , 1993 .

[31]  Liliana Mitoseriu,et al.  Aging effects in pure and doped barium titanate ceramics , 2001 .

[32]  J. C. Garland,et al.  Critical Behavior of the Dielectric Constant of a Random Composite near the Percolation Threshold , 1981 .

[33]  Kui Yao,et al.  Development of Ba-Ti-B glass-ceramic thick-film capacitors by sol-gel technology , 1998 .

[34]  Jonathan L. Paulsen,et al.  Highly accelerated lifetesting of base-metal-electrode ceramic chip capacitors , 2002, Microelectron. Reliab..

[35]  R. Ulrich.  Matching embedded capacitor dielectrics to applications , 2004 .

[36]  J. Fothergill,et al.  The effect of water absorption on the dielectric properties of epoxy nanocomposites , 2008, IEEE Transactions on Dielectrics and Electrical Insulation.

[37]  S. Wada,et al.  Size dependence of dielectric properties for nm-sized barium titanate crystallites and its origin , 2005 .

[39]  R. Boudreau.  Foreword contributions from the 50th electronic components and technology conference , 2001 .

[40]  Nanju Na,et al.  Modeling and transient simulation of planes in electronic packages , 2000 .

[41]  Takuya Yamamoto,et al.  New non‐reinforced substrates for use as embedded capacitors , 2004 .

[42]  W. Minford,et al.  Accelerated Life Testing and Reliability of High K Multilayer Ceramic Capacitors , 1981 .

[43]  S. Bhattacharya,et al.  High dielectric constant polymer-ceramic (Epoxy varnish-barium titanate) nanocomposites at moderate filler loadings for embedded capacitors , 2006 .

[44]  A. Kingon,et al.  Lead Zirconate Titanate Thin Films on Base-Metal Foils: An Approach for Embedded High-Permittivity Passive Components , 2004 .

[45]  Yang Shen,et al.  High Dielectric Performance of Polymer Composite Films Induced by a Percolating Interparticle Barrier Layer , 2007 .

[46]  Michael Osterman,et al.  Effectiveness of embedded capacitors in reducing the number of surface mount capacitors for decoupling applications , 2010 .

[47]  M. Miyayama,et al.  Barium titanate fabricated from fur-fibres , 1996 .

[48]  Jeffrey W. Herrmann,et al.  Cost and production analysis for substrates with embedded passives , 2004 .

[49]  Hari Singh Nalwa,et al.  Handbook of Low and High Dielectric Constant Materials and Their Applications , 1999 .

[50]  Chan Eon Park,et al.  Humidity effects on adhesion strength between solder ball and epoxy underfills , 1997 .

[51]  Rao Tummala,et al.  Integral passives for next generation of electronic packaging: application of epoxy/ceramic nanocomposites as integral capacitors , 2001 .

[52]  Hiroshi Ochi,et al.  High reliability internal capacitor of LTCC , 1994 .

[53]  P. Jain,et al.  Embedded thin film capacitors-theoretical limits , 2002 .

[54]  V. Sundaram,et al.  Design, Modeling, and Characterization of Embedded Capacitor Networks for Core Decoupling in the Package , 2007, IEEE Transactions on Advanced Packaging.

[55]  K. Paik,et al.  Screen Printable Epoxy/BaTiO3 Embedded Capacitor Pastes with High Dielectric Constant for Organic Substrate Applications , 2008 .

[56]  M. Pecht,et al.  Reliability of Embedded Planar Capacitors With Epoxy– $\hbox{BaTiO}_{3}$ Composite Dielectric During Temperature–Humidity–Bias Tests , 2012, IEEE Transactions on Device and Materials Reliability.

[57]  Yang Rao,et al.  A precise numerical prediction of effective dielectric constant for polymer-ceramic composite based on effective-medium theory , 2000 .

[58]  Anthony J. Rafanelli,et al.  Plastic Encapsulated Microelectronics; Materials, Processes, Quality, Reliability, and Application , 1997 .

[59]  Telesphor Kamgaing,et al.  Future Package Technologies for Wireless Communication Systems , 2005 .

[60]  I. Lin,et al.  Dispersion of nano-sized BaTiO3 powders in nonaqueous suspension with phosphate ester and their applications for MLCC , 2008 .

[61]  Y. Lo,et al.  Theory and experiment on microstrip antennas , 1979 .

[62]  Jin Woo Kim,et al.  Reliability Estimation and Failure Analysis of Multilayer Ceramic Chip Capacitors , 2003 .

[63]  Burtrand I. Lee,et al.  Dielectric constant and mixing model of BaTiO3 composite thick films , 2003 .

[64]  Stephen J. Sangwine.  Electronic Components and Technology: Engineering Applications , 1987 .

[65]  Voya R. Markovich,et al.  Fabrication, integration and reliability of nanocomposite based embedded capacitors in microelectronics packaging , 2008 .

[66]  Richard Ulrich,et al.  Integrated passive component technology , 2003 .

[67]  K. Moon,et al.  Optimization of Epoxy-Barium Titanate Nanocomposites for High Performance Embedded Capacitor Components , 2007, IEEE Transactions on Components and Packaging Technologies.

[68]  R. Sarathi,et al.  Understanding the thermal, mechanical and electrical properties of epoxy nanocomposites , 2007 .

[69]  T. Ozaki,et al.  Effects of nano- and micro-filler mixture on electrical insulation properties of epoxy based composites , 2006, IEEE Transactions on Dielectrics and Electrical Insulation.

[70]  Yang Rao,et al.  Di-block copolymer surfactant study to optimize filler dispersion in high dielectric constant polymer-ceramic composite , 2003 .

[71]  G. May,et al.  Effect of growth parameters on TiO2 thin films deposited using MOCVD , 1997 .

[72]  Jiongxin Lu,et al.  Recent advances in high-k nanocomposite materials for embedded capacitor applications , 2008, IEEE Transactions on Dielectrics and Electrical Insulation.

[73]  L. Burton,et al.  Electrical Conduction Mechanisms of Barium-Titanate-Based Thick-Film Capacitors , 1987 .

[74]  T. Yoko,et al.  Preparation of La0.5Li0.5TiO3 perovskite thin films by the sol–gel method , 1997 .

[75]  A. Madou,et al.  Electrical behavior of decoupling capacitors embedded in multilayered PCBs , 2001 .

[76]  Rao Tummala,et al.  Colloidal processing of polymer ceramic nanocomposites for integral capacitors , 2001 .

[77]  Michael G. Pecht,et al.  Temperature and voltage aging effects on electrical conduction mechanism in epoxy-BaTiO3 composite dielectric used in embedded capacitors , 2011, Microelectron. Reliab..

[78]  Takeshi Nomura,et al.  Reliability of multilayer ceramic capacitors with nickel electrodes , 1996 .

[79]  J. H. D. Folster,et al.  RESEARCH AND DEVELOPMENT PROGRAM INTRINSIC RE LIABILITY SUBMINIATURE CERAMIC CAPACITORS. , 1963 .

[80]  M. Nakamura,et al.  Preparation and characterization of glass composite using metal particles coated with semiconductive SnO2 fine particles obtained via sol—gel method , 1997 .

[81]  Bruce Archambeault,et al.  EMI/EMC Computational Modeling Handbook , 1998 .

[82]  U. Paik,et al.  The effect of electrostatic repulsive forces on the stability of BaTiO3 particles suspended in non-aqueous media , 1998 .