Microelectronics Industry Research Articles

Highly active mesoporous Co–Al2O3 sorbents for the efficient destructive sorption of NF3

Nitrogen trifluoride (NF3) is widely used as an etching gas and cleaning agent in the microelectronics industry. However, it is a novel and powerful greenhouse gas. The destructive sorption of NF3 over metal oxides is an efficient route to control its emission. Here, several sorbents of homogeneous Co–Al2O3 oxides were prepared via changing the molar ratios of HNO3 to Al(OPri)3 in the raw materials, whose impact on the structure of sorbents and the reactivity for NF3 destructive sorption was investigated. It is found that the destructive reactivity of sorbents is strongly affected by their surface area and pore volume. Impressively, the optimal Co–Al2O3-2.45 sorbent with the largest surface area and pore volume presents the longest time of NF3 complete destruction, which is clearly more active than most of the results in the literature. Furthermore, the F migration over the solid interfaces between Al2O3 and Co oxides in Co–Al2O3 sorbents enhances the efficient destruction of NF3. These findings well explain the better reactivity of Co–Al2O3 complex oxides than bare Al2O3, and are beneficial to develop more efficient sorbents for NF3 destruction.

New π spring for piezostack-driven jetting dispenser

With the rapid development of the microelectronics industry, industrial applications have put forward higher requirements on the efficiency and reliability of the dispenser, and the traditional piezoelectric dispenser uses ordinary spring preloading way, in this way, the dispenser is difficult to obtain a higher dispensing frequency, because of to the wear and tear between the connecting components and the subsequent response. In this paper, a new type of wire cutting π type spring is designed and manufactured, which solves the problem that traditional piezostack dispensers can not get the high operating frequency. In the structural design of π type spring, the stiffness of the reset spring is studied, and the output displacement characteristics of the reset spring are verified. Finally, we established the glue test system, and the point spray test is carried out on the fuse breaker and glycerol alcohol mixture at its operating frequency of 666 Hz. The mass of the fuse is measured by an electronic scale and its mass distribution is 3.08 mg (±2.5%). The diameter of the glycerol alcohol mixture sprayed by dispensing can reach 217.3 µm. By analyzing the mass and size of the glue point, it is verified that the piezoelectric dispenser with π-type reset spring can achieve high-frequency dispensing accuracy and small drop size.

Synthesis and characterization of new low molecular weight aluminum organometallic complexes using amino/imine type ligands with possible uses in Atomic Layer Deposition processes

The driver of development and innovation in the microelectronics industry is the miniaturization of the components that make up each technological node. This miniaturization has given rise to new challenges for traditional materials and the need for new fabrication methods with sub-nanometer precision.Based on this, numerous methods have emerged for the fabrication of this type of nanometer materials, among which chemical deposition processes stand out. An industrial example of this type of chemistry is the so-called ALD (Atomic Layer Deposition), which generates deposition of nanometric metal layers, using precursors in a gaseous state.The use of metallic precursors in gaseous state, generates that the process has as a key factor the correct molecular design of the inorganic/organometallic material, since the method imposes strict requirements to the chemical and physical properties of these compounds, such as thermal stability, volatility, synthetic scaling, among others. With this in mind, in this research, new aluminum complexes were synthesized using TMA and imino/amine type ligands with low molecular weight substituents (isopropyl, tertbutyl), to generate stable and volatile liquid complexes in inert atmosphere at room temperature.Finally, four liquid complexes are obtained, stable in nitrogen atmosphere, with yields of 70%. Due to the mentioned characteristics, these complexes could be used as precursors for the deposition of Al and Al2O3 films. In addition, it is demonstrated that the use of TMA in this type of ligands can generate a methylation in the chain of this molecule, which opens a new field in the development of aluminum organometallic complexes.

Area-selective atomic layer deposition of Al2O3 using inkjet-printed inhibition patterns and lift-off process

Area-selective atomic layer deposition (AS-ALD) has been studied as an alternative method for metal oxide ALD film patterning in the microelectronics industry. To perform AS-ALD, area-deactivation or -activation processes should be implemented in advance using selective surface modification through a photography-based lift-off process and printing techniques. This study introduces a novel approach for Al2O3 AS-ALD using inkjet-printed inhibition patterns. ALD-inhibition patterns with two-layer structures of fluorocarbon (FC) thin film and photoresist (PR) were patterned by inkjet printing. Low surface energy FC thin films were used to block the Al2O3 nucleation and growth during the ALD process, and PR was patterned to easily remove ALD-inhibition patterns using a lift-off process. To demonstrate AS-ALD, an Al2O3 thin film approximately 10 nm thick was deposited via an in-house built system with a multiple-slit gas source. The proposed AS-ALD method was evaluated for topological analysis using atomic force microscopy and surface composition analysis using a time of flight secondary ion mass spectrometry after Al2O3 deposition and a lift-off process. Finally, a 6 nm thick Al2O3 film was selectively patterned by the lift-off process using an inkjet-printed 1.28 μm thick FC-covered PR inhibition pattern.

Graphene/Polyolefin Elastomer Films as Thermal Interface Materials with High Thermal Conductivity, Flexibility, and Good Adhesion

Heat dissipation has become a central issue for the development of the microelectronic industry. Thermal interface materials (TIMs) have been widely applied to electron component cooling, which is used to bond the heat spreader and the chip together. Most research on TIMs has only dealt with thermal conductivity enhancement. However, the mechanical properties and adhesion of TIMs are indispensable for practical applications, as well as postcleaning to remove TIMs. A graphene nanosheet/polyolefin elastomer (GNP/POE) film was designed and prepared by a facile method, in which the heat conduction paths were efficiently constructed, and the good mechanical properties of POE were reserved. The thermal conductivity of as-prepared GNP/POE film can reach 1.07 W m–1 K–1 at an extremely low filler loading of 0.62 wt %. Furthermore, the tensile strength, elongation at break, and adhesion of the prepared GNP/POE film are as good as those of commercial TIM productions. The prepared GNP/POE film can be used as TIMs for chip cooling and exhibits a good heat dissipation effect. Additionally, the prepared GNP/POE film can be peeled off from the chip without residue, after the chip has finished running, which is significant for practical production. This work provides valuable information and insight into the design and fabrication of TIMs in the future.

Linker engineering of larger POSS-based ultra-low-k dielectrics toward outstanding comprehensive properties

Low-dielectric-constant (low-k) materials are an indispensable part of microprocessors as they can alleviate electronic crosstalk, charge build-up, and signal propagation delay. However, existing low-k materials usually have k values higher than 2 and inferior thermo-mechanical properties, which restrict the development of microelectronic devices. Although we have recently discovered that larger polyhedral oligomeric silsesquioxanes (POSS) are useful building blocks for fabricating advanced ultra-low-k materials, it remains to be seen whether a POSS cage and linker could be leveraged to tune the structure-property of the materials and create ultra-low-k materials with improved comprehensive properties. Herein, we propose a series of POSS-based hybrid materials (i.e., c-TnPBn and c-TnFn, n = 8, 10, and 12) that consist of distinct POSS cages and linkers. When the linker is kept identical, the gradual enlargement of the POSS cage enhances the porosity/free volume fraction of materials, resulting in quasi-linearly reduced k values for the resulting materials (k = 1.93 for c-T12PB12, 2.14 for c-T12F12). Meanwhile, the materials’ comprehensive properties can be significantly improved by increasing the POSS cage size or varying the linker’s length and type. As a result, ultra-low-k materials with good processability, low surface roughness (< 0.40 nm), excellent thermostability (> 480 °C), mechanical properties (elastic modulus > 2.5 GPa), and hydrophobicity have been obtained, and the low-k values can be maintained under high temperature (e.g., 300 °C) and wet condition. This work reveals the critical contribution of POSS cage size and linker to the structure and properties of POSS-based low-k materials and offers promising materials for the future of the microelectronic industry.

Off-Stoichiometry Thiol-Ene Polymers: Inclusion of Anchor Groups Using Allylsilanes.

The use of polymers in silicon chips is of great importance for the development of microelectronic and biomedical industries. In this study, new silane-containing polymers, called OSTE-AS polymers, were developed based on off-stoichiometry thiol-ene polymers. These polymers can bond to silicon wafers without pretreatment of the surface by an adhesive. Silane groups were included in the polymer using allylsilanes, with the thiol monomer as the target of modification. The polymer composition was optimized to provide the maximum hardness, the maximum tensile strength, and good bonding with the silicon wafers. The Young's modulus, wettability, dielectric constant, optical transparency, TGA and DSC curves, and the chemical resistance of the optimized OSTE-AS polymer were studied. Thin OSTE-AS polymer layers were obtained on silicon wafers via centrifugation. The possibility of creating microfluidic systems based on OSTE-AS polymers and silicon wafers was demonstrated.

Enhancing thermal conductivity of epoxy composites via f‐BN@f‐MgO hybrid fillers assisted by hot pressing

AbstractHigh thermal conductive polymeric composites are extremely desired for the thermal management of electronic devices due to the rapid development of the modern microelectronic industry. Herein, the functionalized boron nitride (BN) and magnesium oxide (MgO) hybrid fillers (f‐BN@f‐MgO) were synthesized and used to prepare the enhanced thermal conductive epoxy (EP) composites through the hot‐pressing method. The results demonstrated that the covalent binding of BN and MgO in the hybrid fillers reduced the interface thermal resistance effectively between fillers and matrix and the hot‐pressing induced force facilitated the construction of the continuous thermal conduction paths. Consequently, the as‐prepared epoxy composite at 40 wt% hybrid fillers loading had high thermal conductivity (TC) (1.97 W/[m·K]), outstanding insulating performance (6.9 × 1015 Ω cm) and excellent thermal stability. Furthermore, a probable thermal conduction mechanism was proposed to illustrate the high TC of the epoxy composite. Therefore, this study provides a new approach to preparing epoxy composites with outstanding performances.

Scalability of Large-Scale Photonic Integrated Circuits

To keep up with the growing bandwidth demands, photonic integrated circuits (PICs) have been widely employed in various application scenarios where high capacity and high-bandwidth-density interconnects are required. However, it is challenging to scale the PICs toward future petabit per second capacity requirements. We study the scalability bottlenecks of PICs in terms of guiding materials, dense integration approaches, wide-band optical sources, and high-efficiency tunable and modulation devices. We also look for possible solutions to address these challenges. In the end, we provide a perspective on future PIC development. Moore’s law for integrated photonics may last for a much shorter time than that in the microelectronics industry, requiring significant innovations and technological breakthroughs in PIC research.

Experimental and computational investigation of complexing agents on copper dissolution for chemical mechanical polishing process

Complexing agents are important additives in chemical mechanical polishing (CMP) slurries, and they play key roles in the removal rate (RR) and surface quality of copper (Cu). However, it is a great challenge to clarify the complexing mechanism of Cu at the microscopic level. In this study, the effects of glycine (GLY), potassium tartrate (PT), and potassium citrate (CAK) on the RR and dissolution behavior of Cu are investigated. The results show that the complexing capability is in the order of GLY > PT > CAK. The complexing mechanism is elucidated by single-frequency electrochemical impedance spectroscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectrometer, density functional theory, and molecular dynamics simulation. Copper hydroxide (Cu(OH)2) on the Cu surface ionizes, giving rise to Cu2+ ions, which are attracted by negatively charged oxygen atoms of carboxylate groups in complexing agents, resulting in the formation of water-soluble complexes. This process destroys the integrity of the oxide layer on the Cu surface. Therefore, the oxide layer can be easily removed by a polishing pad. These findings provide significant theoretical guidance for the development of Cu CMP slurries in the microelectronics industry.

The low-k epoxy/cyanate nanocomposite modified with epoxy-based POSS: The effect of microstructure on dielectric properties

Epoxy-based silsesquioxane (EOVS) was successfully oxidized from octavinyl silsesquioxane (OVS) and then prepared the E51/BADCy/EOVS nanocomposites with epoxy resin and cyanate ester. With EOVS additions, a lower value of dielectric constant was achieved due to the increased free volume. The positron annihilation lifetime spectroscopy (PALS) demonstrated more nanocavity introduced by POSS increased the free volume of the system, and the crosslinking density calculated from DMA was combined to determine the spatial structure of molecular chains in nanocomposites. Subsequently, the internal microstructure of materials and the types of dipoles were confirmed by Fourier transform infrared spectroscopy (FTIR) and electron paramagnetic resonance spectroscopy (EPR), and the effect of various dipoles on the dielectric loss was fully discussed. Surprisingly, the dielectric constant and dielectric loss even decreased to 2.0 and 0.0036 (1 MHz), which suggested E51/BADCy/EOVS nanocomposites are promising candidates in the aspect of microelectronics industry.

Conduction Mechanism and Influencing Factors of SiC MOSFET

With the rapid development of the microelectronics industry, power semiconductor devices are getting more and more attention from the industry. At the same time, discussions on the application of power semiconductor materials have never stopped. Over the years, SiC material has stood out because of its superior physical characteristics. Compared with traditional Si MOSFET technology, SiC MOSFET technology has better physical characteristics in some aspects and has a broader market prospect. This paper introduces the conduction mechanism of SiC MOSFET and its performance factors, and the volume effect, bias temperature instability, and threshold voltage drift of SiC MOSFET are discussed. This paper is helpful in understanding the broad application prospects of SiC MOSFET technology and the difference and reform between SiC MOSFET and traditional Si MOSFET.

Highly rigid and functional poly(benzimidazole sulfone)s from 5,6‐dimethoxy‐1,3‐dihydro‐2H‐benzo[d]imidazol‐2‐one monomer

AbstractA series of poly(benzimidazole sulfone)s (PBSs) and poly(benzimidazole ketone)s (PBKs) containing 5,6‐dimethoxy‐1,3‐dihydro‐2H‐benzo[d]imidazol‐2‐one (MBIO) have been synthesized by C–N/C–O coupling with different percentages of three other diphenol monomers under similar conditions. The structure of PBS‐MBs and PBK‐MBs was confirmed using 1H NMR and Fourier transform infrared spectroscopies, and X‐ray diffraction data revealed that all the polymers are in an amorphous state. Due to the introduction of methoxy, the polymers were more soluble in common aprotic polar solvents. The intrinsic viscosity of the synthesized polymers was measured with an Ubbelohde viscometer, ranging from 0.38 to 1.35 dL g−1. The MBIO‐based polymers have a remarkably good thermal stability with a high glass transition temperature of up to 305.1 °C. Furthermore, the wavelength of maximum fluorescence emission from homopolymers is around 414 nm with emission of blue light in N‐methyl‐2‐pyrrolidone solution (1 mg L−1) and around 530 nm in films. They also showed low dielectric constants (κ = 2.60–3.10 at 1 MHz) and low water absorption (0.22–0.58%). It was encouraging to discover that these polymers have potential utility for the microelectronics industry, in which good solubility facilitates processing and molding, excellent thermal stability allows devices to be used under harsh conditions, low water absorption prevents device expansion and shrinkage and low dielectric constant is desired to prevent crosstalk between conducting paths. © 2023 Society of Industrial Chemistry.

Special Section on InterPACK2021

The International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems (InterPACK) is a flagship conference of ASME Electronic and Photonic Packaging Division (EPPD). It has served as an international forum within the ASME society to share and exchange latest progresses in the research, development, and applications of electronic and photonic packaging since 1992. The aim of ASME Journal of Electronic Packaging (JEP) Special Section for InterPACK is to publish outstanding papers from technical tracks of InterPACK2021, which was held virtually amid COVID-19 pandemic worldwide. This Special Section of the ASME JEP publishes nine papers presented at the InterPACK2021 in the areas of electronics and photonics packaging, micro-electronics reliability, and advanced thermal management from the silicon, package, to data center level. All nine papers published in this JEP Special Section for InterPACK2021 went through a standard peer-review process for journal papers published by ASME.The micro-electronics industry is facing challenges to meet demanding performance and functional needs of high-performance computing (HPC), artificial intelligence (AI), 5 G/mm Wave, and power electronic devices. In order to close this gap, in parallel with new breakthroughs in advancing silicon node, the semiconductor industry is also embracing advanced integrated circuits (IC) packaging technologies, including heterogeneous integration, 2.5D/3D IC packaging, chiplet, additive manufacturing, novel modeling and characterization techniques, and others. This Special Section reflects latest progresses in the IC packaging by publishing nine papers presented at ASME InterPACK2021. We gratefully acknowledge all the authors who have revised their original conference papers for this Special Section and the reviewers who have spent tremendous time and efforts to help improve overall quality of the papers for this Special Section. We also would like to thank the ASME JEP Editor-in-Chief (EIC), Professor Shi-Wei Ricky Lee for his guidance and support, and the assistant to EIC, Dr. Jeffery Lo for his help in this journey.

Tunable rapid electron transport in titanium oxide thin films

Rapid electron transport triggers many novel physical phenomena and becomes a critical point for high-speed electronics. Two-dimensional electron gas (2DEG) has drawn great attention due to its high electron mobility, and this has been observed in different materials, such as semiconductor, oxide interfaces, and 2D materials. In this paper, we report, for the first time, the existence and electrical manipulation of 2DEG in the Schottky quantum well, which was formed in the titanium oxide thin films. We take the asymmetry interface electron scattering effect into consideration when studying the electrical transport properties of our multilayer thin films. We found electrons would be transferred from the low-mobility semiconducting and metallic conductive channels to the high-mobility 2DEG conductive channel with an in-plane applied electric field. Therefore, electron concentration and mobility of the 2DEG formed in the Schottky quantum well could be tuned, and the nano-devices exhibited non-linear voltage–current curves. The differential resistivity of the nano-devices could decrease by two orders with increasing electric field at room temperature. Weak electron localization of electrons was experimentally observed in our nano-devices at low temperature, which further demonstrated the existence of 2DEG in the Schottky quantum well. Our work will provide us new physics about the rapid electron transport in the multilayer thin films and bring novel functional devices for the modern microelectronic industry.

Unprecedented atomic surface of silicon induced by environmentally friendly chemical mechanical polishing.

Silicon (Si) dominates the integrated circuit (IC), semiconductor, and microelectronic industries. However, it is a challenge to achieve a sub-angstrom surface of Si. Chemical mechanical polishing (CMP) is widely used in the manufacturing of Si, while toxic and polluted slurries are usually employed in CMP, resulting in pollution to the environment. In this study, a novel environmentally friendly CMP was developed, in which a slurry is composed of ceria, hydrogen peroxide, sodium pyrophosphate, sodium carboxymethyl cellulose, sodium carbonate, and deionized water. After CMP, the surface roughness Sa was 0.067 nm with a measurement area of 50 × 50 μm2, and a sub-angstrom surface is achieved. To the best of our knowledge, it is the lowest surface roughness in such a large area. Transmission electron microscopy shows that the thickness of the damaged layer after CMP is 2.8 nm. X-ray photoelectron spectroscopy and infrared Fourier transformation reveal that during CMP, a redox reaction firstly took place between Ce3+ and Ce4+. Si and ceria are hydroxylated, forming Si-OH and Ce-OH, then dehydration and condensation occur, generating Si-O-Ce. These findings propose new insights to fabricate a sub-angstrom surface of Si for use in IC, semiconductor, and microelectronic industries.

Cobalt-substituted ZnS QDs: a diluted magnetic semiconductor and efficient photocatalyst.

Recently, understanding the origin of induced magnetic characteristics in transition metal atom-doped QDs has been a major focus owing to their potential applications in the area of spintronic devices. A detailed experimental and theoretical investigation was conducted to understand the physical properties of Co-doped ZnS QDs containing different weight percentages of Co atoms [CoxZn1-xS (x = 0.00, 0.03, 0.06, and 0.09)], prepared using chemical co-precipitation techniques. X-ray diffraction studies proved that all the prepared QDs formed an extremely pure cubic zinc blende crystallographic phase free of contaminants. The validation of the quantum dot nature of all the samples was provided by the HRTEM images, BET studies, and blue shift in the absorption spectra. Both the obtained FTIR and PL spectra at room temperature also confirmed the phase purity of the prepared QDs. The observed weak ferromagnetic behavior of the doped samples was due to the presence of p-d hybridization between the 3d levels of Co2+ ions and 3p levels of S2- ions of the host ZnS QDs. Hysteresis loops that were obtained at room temperature validated this weak ferromagnetic nature. These obtained results were also supported theoretically using DFT calculations. FDTD simulations provided a detailed explanation for the observed blue shift in the absorption spectra originating from the quantum confinement effect of doped and undoped ZnS QDs. The dielectric properties of all the samples were examined properly, and it was also found that the grain boundaries contributed effectively to providing the dielectric response. The doped ZnS sample containing more Co dopants at low frequencies showed a progressive rise in polarisation loss. In addition, Co-doped ZnS QDs are efficient photocatalysts. A pH-dependent photodegradation test of ciprofloxacin (CIP) antibiotic was conducted using 9% Co-doped ZnS QDs. It was observed that 9% Co-doped ZnS nanocatalysts has sufficient capability to degrade CIP to around 94.7% in a solution of pH 10 within one hour. Therefore, besides showing photocatalytic effects, Co-doped ZnS QDs act as ideal dilute magnetic semiconductors (DMSs) and will undoubtedly become excellent candidates for the microelectronics industry because of their special ability to exhibit spin-dependent magneto-electro-optical properties that find use in spin-polarized light-emitting diodes, solid-state lasers, and spin-transistor devices.

Multifunctional boron nitride nanosheets cured epoxy resins with highly thermal conductivity and enhanced flame retardancy for thermal management applications

With the rapid improvement of microelectronics integration and assembly technology, the increasing heat flux density in electronic devices puts forward higher requirements for efficient heat dissipation and fire safety of thermal management materials (TMMS). In this work, we proposed a facile method to exfoliate and organically modify hexagonal boron nitride (h-BN) via phytic acid assisted-ball milling and self-assembly of zeolitic imidazolate frameworks (ZIF-8). And the obtained multifunctional additive (BAZF) successfully achieved the synergistic integration of highly thermal conductivity and superior fire safety in epoxy resin (EP). Besides, BAZF was also utilized as a curing agent to initiate the crosslinking reaction of EP, and the activation energy (Eα) and kinetic parameters of curing process were obtained by the fitting of Kissinger and Crane equation. Compared to EP, the peak heat release rate (PHRR), smoke production rate (SPR) of EP composites containing 16 wt% BAZF significantly reduced by 58.2% and 47.7%, respectively, showing superior flame retardancy. Contributed by the good compatibility between fillers and matrix, BAZF significantly enhanced the thermal conductivity and mechanical properties of EP composites. As a result, this work provides a cost-effective route for the preparation of epoxy-based TMMS, which shows significant potential application in modern microelectronic industry.

Thermal, Mechanical and Dielectric Properties of Polyimide Composite Films by In-Situ Reduction of Fluorinated Graphene.

Materials with outstanding mechanical properties and excellent dielectric properties are increasingly favored in the microelectronics industry. The application of polyimide (PI) in the field of microelectronics is limited because of the fact that PI with excellent mechanical properties does not have special features in the dielectric properties. In this work, PI composite films with high dielectric properties and excellent mechanical properties are fabricated by in-situ reduction of fluorinated graphene (FG) in polyamide acid (PAA) composites. The dielectric permittivity of pure PI is 3.47 and the maximum energy storage density is 0.664 J/cm3 at 100 Hz, while the dielectric permittivity of the PI composite films reaches 235.74 under the same conditions, a 68-times increase compared to the pure PI, and the maximum energy storage density is 5.651, a 9-times increase compared to the pure PI films. This method not only solves the problem of the aggregation of the filler particles in the PI matrix and maintains the intrinsic excellent mechanical properties of the PI, but also significantly improves the dielectric properties of the PI.

The enhancement of polymer composite coating by using a waste glass powder as alternative reinforcement

Epoxy-based composites are widely used as a surface coating in the aircraft, automobile and microelectronic industries due to theirs great mechanical properties, excellent strength-to-weight ratio, lightweight, and good machinability. However, the epoxy-based coating has poor corrosion resistance in a severe environment such as in seawater. The incorporation of various fillers into epoxy resins can yield high-performance composites having high strength, lightweight, multifunctional properties and also improve corrosion resistance. Therefore, this study focuses on the preparation of inorganic nanoparticles filled in an epoxy resin matrix to create high-performance composites. The waste glass powder (WGP) was selected to use as the alternative reinforcement in epoxy resin-based composites in order to search for a sustainable and recycling filler along with the use of commercial SiO2 as a comparative filler. The broken glass from household waste was processed through a high-speed vibratory milling technique until reaching the micrometer level. The physical properties, microstructure, mechanical properties, electrical properties, water absorption and corrosion resistance of all composites are investigated. The results show that after mixing WGP with an epoxy resin matrix, both Vickers hardness and abrasion resistance significantly increase compared to the neat epoxy resin whereas the water absorption ability of composites decreases. For the electrical properties, WGP does not show a significant effect on dielectric constant, dielectric loss and resistivity whereas the anticorrosive performances of the WGP/epoxy resin composite coating are improved.