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Interfacial adhesion and interfacial thermal resistance (ITR) are two critical factors in the interfacial force and energy transfer, but it is difficult to simultaneously achieve the desirable interfacial adhesion and ITR. Here, we overcome this challenge by fabricating an elastomer composite consisting of polydimethylsiloxane (PDMS) and micro-scale spherical aluminum (Al) fillers, which offers the high adhesion strength (1.28 MPa), high interfacial adhesion energy (528.4 J/m2), and low ITR (0.028 mm2·K/W) between the PDMS/Al elastomer composite and substrates. We further propose a quantified physical model to establish the relationship between interfacial adhesion and ITR for low phonon mismatch interfaces. This work will contribute to the development of interface science and guide the regulation of force and energy transfer at interface for wide range applications, such as electronic packaging, thermal storage, sensors, and medicine. [ABSTRACT FROM AUTHOR]

Copper is the most common interconnecting material in the field of microelectronic packaging, which is widely used in advanced electronic packaging technologies. However, with the trend of the miniaturization of electronic devices, the dimensions of interconnectors have decreased from hundreds of microns to tens of or even several microns, which has brought serious reliability issues. As a result, nanotwinned copper (nt-Cu) has been proposed as a potential candidate material and is being certified progressively. Firstly, the physical properties of nt-Cu have been widely studied. Notably, the higher thermal stability and oxidation resistance of the (111) texture causes nt-Cu to maintain excellent physical properties under high-temperature serving conditions. Secondly, recent works on the electrolyte and electroplating processes of nt-Cu on wafer substrates are summarized, focusing on how to reduce the thickness of the transition layer, improve the twin density, and achieve complicated pattern filling. Thirdly, nt-Cu can effectively eliminate Kirkendall voids when it serves as UBM or a CuP. Additionally, the high (111) texture can control the preferred orientation of interfacial intermetallic compounds (IMCs) at the Cu–Sn interface, which should be helpful to improve the reliability of solder joints. nt-Cu has superior electromigration resistance and antithermal cycling ability compared to ordinary copper RDLs and TSVs. Above all, nt-Cu has attracted much attention in the field of microelectronic packaging in recent years. The preparation–performance–reliability interrelationship of nt-Cu is summarized and displayed in this paper, which provides a solid theoretical basis for its practical applications. [ABSTRACT FROM AUTHOR]

Temporary bonding/debonding (TBDB) technologies have greatly contributed to the reliable fabrication of thin devices. However, the rapid development of large-scale, high-precision and ultra-thin devices in the semiconductor field has also proposed more stringent requirements for TBDB technologies. Here, we deliberate the recent progress of materials for temporary bonding and different debonding technologies over the past decade. Several common debonding methods are described, including thermal slide, wet chemical dissolution, mechanical peeling and laser ablation. We review the current status of different debonding technologies and highlight the applications of TBDB technologies in advanced electronic packaging. Possible solutions are proposed for the challenges and opportunities faced by different TBDB technologies. Ultimately, we attempt to propose an outlook on their future development and more possible applications. We believe that the simple schematics and refined data presented in this review would give readers a deep understanding of TBDB technologies and their vast application scenarios in future advanced electronic packaging. [ABSTRACT FROM AUTHOR]

One challenge in the high‐performance dielectric material of polyimide (PI) is to obtain the excellent comprehensive properties at low curing temperature for advanced IC package. In this work, 6‐aminoquinoline (AQL) is introduced through covalent bonds for end capping to obtain a low‐temperature curable PI at first. The results demonstrate that with very limited introduce (2.76%) of AQL, the imidization index could reach as high as 1.01 at 200°C. Then, fluorinated nano carbon (FC) is further introduced resulting in the fluorinated nano carbon/polyimide (FCPI) composites, which effectively reduces the dielectric constant (1 wt%, 2.75 @ 1 MHz). Besides, the as‐prepared FCPIs also possess excellent thermal property of which FCPI‐0.3 exhibited the 5% weight loss temperature of 540°C and the glass transition temperature is also as high as 385°C. Furthermore, the tensile strength of the film is 127 MPa, the elongation at break is around 15.82%, and the Youngs' modulus is about 3.10 GPa proving the superior mechanical property. As a result, the successful preparation of the FCPI nanocomposites not only possess low‐temperature curing and low‐dielectric performance but also exhibit excellent thermal and mechanical properties, which shows a wide range of application prospects in the field of microelectronics for the advanced electronic package. [ABSTRACT FROM AUTHOR]

Thermal interface materials (TIMs) used to fill the gaps between chip and heat sink are one of the most important materials for electronic packaging. Low thermal resistance is the key to achieving high heat dissipation efficiency. However, most studies only focused on how to enhance the thermal conductivity of the gel TIMs and ignored the thermal resistance, which is significantly influenced by the rheological properties. In this work, we aimed to investigate the effects of in situ modification of aluminum fillers on the rheological properties and thermal resistance of the gel TIMs. Six modifiers were compared for their ability to improve the compatibility between aluminum fillers and silicone oil. The rheological results showed that the gel TIM modified with 0.170 wt% dodecyl trimethoxysilane had the best rheological properties, including the lowest viscosity and yield stress, the weakest Payne effect, and the shortest relaxation time. The thermal resistance measurements further verified that the bond line thickness and thermal resistance of gel TIMs were determined by the rheological properties. This work provides a reference for the formulation design and process optimization of gel TIMs. [ABSTRACT FROM AUTHOR]

Thermal interface material (TIM) is pivotal for the heat dissipation between layers of high-density electronic packaging. The most widely used TIMs are particle-filled composite materials, in which highly conductive particulate fillers are added into the polymer matrix to promote heat conduction. The numerical simulation of heat transfer in the composites is essential for the design of TIMs; however, the widely used finite element method (FEM) requires large memory and presents limited computational time for the composites with dense particles. In this work, a numerical homogenization algorithm based on fast Fourier transform was adopted to estimate the thermal conductivity of composites with randomly dispersed particles in 3D space. The unit cell problem is solved by means of a polarization-based iterative scheme, which can accelerate the convergence procedure regardless of the contrast between various components. The algorithm shows good precision and requires dramatically reduced computation time and cost compared with FEM. Moreover, the effect of the particle volume fraction, interface thermal resistance between particles (R-PP), interface thermal resistance between particle and matrix (R-PM), and particle size have been estimated. It turns out that the effective conductivity of the particulate composites increases sharply at a critical filler volume fraction, after which it is sensitive to the variation of filler loading. We can observe that the effective thermal conductivity of the composites with low filler volume fraction is sensitive to R-PM, whereas the it is governed by R-PP for the composites with high filler content. The algorithm presents excellent efficiency and accuracy, showing potential for the future design of highly thermally conductive TIMs. [ABSTRACT FROM AUTHOR]

Low dielectric constant and low dissipation factor, superior hydrophobicity, excellent thermal and mechanical property, and good optical performance are desired for advanced electronic packaging of fan‐out wafer level package (FO‐WLP). An effective approach was introduced to fabricate novel fluorinated graphene/polyimide(FG/PI) nanocomposite films in this paper. FG nanosheets exhibit excellent dispersion in the PI matrix due to their high surface area with some oxygen‐containing functional groups, and individual graphitized planar structure. Besides, the effects of the addition of FG on the dielectric, optical, mechanical, thermal properties as well as the hydrophobicity of the films are investigated with controlled amounts of FG. The dielectric constant and loss can be as low as 2.64 (at 106 Hz) and 0.00176 for PI‐0.5wt% FG. And with the increase of the loading of FG, the thermal stability (T5 = 514°C) and mechanical property (tensile modulus = 2.11GPa, tensile strength = 93.23 MPa, elongation at break = 11.60%) has been improved successfully. Besides, the contact angles have been increased from 83° to 92° showing a superior hydrophobicity which is essential for the FO‐WLP. Moreover, the incorporation of FG also proved excellent optical performance of 88% transmittance at 550 nm. Therefore, with the excellent comprehensive performance, the as‐prepared FG/PI films possess widespread applications in the microelectronics especially in FO‐WLP. [ABSTRACT FROM AUTHOR]

Electrically conductive epoxy adhesive, which combines with Ag sintering materials rather than traditional Pb-based solder materials, attracts wide research interest in modern die attach technology for power electronic packaging owing to its advantages of low processing temperature and high working temperature. In this work, Cu foil and AgNO3 were used as raw materials to synthesize dendritic silver nanostructure with a central trunk of 5–10 μm along with many primary branches of 200 nm. Subsequently, the sintering behavior of the obtained dendritic Ag nanostructures, as low-temperature interconnect material, was systematically investigated under different sintering conditions. Remarkably, the shear strength of the interconnect joints formed from dendritic Ag nanostructures could reach around 21 MPa after sintering for 30 min at 250 °C under a pressure of 10 MPa, whereas the shear strengths of the interconnect joints, which formed from Ag microspheres and microflakes under similar conditions, were only 9 MPa and 11 MPa. We think that the dramatic increment in the shear strength may result from the higher contact area of nanoscale primary branches of the synthesized dendritic structures than Ag microstructures and the low-temperature sintering of their nanoscale primary branches. In addition, the interconnect joint formed from dendritic Ag nanostructures also exhibited high reliability, and it still maintained a high shear strength of 27 ± 2 MPa even after 1000 cycles thermal quenching between − 55 and 125 °C. The thermal resistance and electrical conductivity of these interconnect joints were about 78.89 Wm−1 K−1 and 9.85 × 10–6 Ω cm, respectively, which makes its further interconnect applications feasible. This means that the synthesized special dendritic Ag nanostructure has an excellent potential as a high-performance die attach material for high- and low-temperature power device. [ABSTRACT FROM AUTHOR]

Hexagonal boron nitride nanosheets (h-BNNSs) are excellent candidates as fillers of polymer-based thermal interface materials for electronic packaging. Chemical functionalization of h-BNNSs is necessary to improve the dispersity of the h-BNNSs and reduce the interfacial thermal resistance (ITR) in the composites. However, though studied extensively, the thermal conductivity (TC) of the chemically functionalized h-BNNS/polymer composites is still well below expectations. Among the possible reasons, the TCs of the functionalized h-BNNSs themselves need to be considered thoroughly, as it has been shown that TC of graphene could be dramatically reduced to less than 10 W m−1 K−1 by point defects. Here, we investigate the TCs of hexagonal boron nitride (h-BN) monolayers covalently adsorbed with -OH and -O(CH2)4CH3 groups based on equilibrium molecular dynamics simulations. The TC of the functionalized h-BN decreases monotonically with the increasing concentration of adsorbed groups and tends to saturate at high concentrations. We surprisingly find that the almost-saturated TCs of the functionalized h-BN monolayers are still over 100 W m−1 K−1, about 25% of the value of the pristine h-BN monolayer. The different functional groups have a similar effect on the TCs, which are mostly determined by the extent of distortion of the local 2D structure, and the functionalization introduces no additional anisotropy to the TC. Therefore, we conclude that the chemically functionalized h-BNs themselves are sufficiently thermally conductive as fillers of composites, and the chemical functionalization should be encouraged, with the focus on digging into how to reduce the ITR more effectively. [ABSTRACT FROM AUTHOR]

Single-size 400 nm-SiO and multi-size 1 and 5 μm-SiO were used as fillers in epoxy matrix. The fillers with the larger particle size and multi-size SiO particles mixing is beneficial to lower the viscosity and increase the filler loading. Among the composites, the 60 wt% 5 μm-SiO epoxy composite has the best properties with both low coefficients of thermal expansion (CTE) of 28.8 ppm/°C and low viscosity of ~50 Pa s, which shows its capability to achieve the required low CTE and viscosity values in the electronic packaging. Different theoretical proposals were used to estimate the CTE. Maxwell-Garnett equation fits the experimental data well. In addition, the mixture law and Bruggeman effective medium theory offer the upper and lower limits to the CTE. [ABSTRACT FROM AUTHOR]

ABSTRACT The modified novolac epoxy resins with furan pendant groups were prepared by novolac epoxy resin and furfuryl alcohol and then crosslinked by bifunctional maleimide via Diels-Alder (DA) chemistry to obtain the thermally reversible and self-healing novolac epoxy resins. The as-prepared crosslinked novolac epoxy resins were characterized by FT-IR, NMR, TGA, and DMA. The results indicate that the novel crosslinked novolac epoxy resins present higher storage modulus (2.37 GPa at 30°C) and excellent thermal stability (348°C at 5% mass loss). Furthermore, the thermal reversible and self-healing properties were studied in detail by DSC, SEM, thermal re-solution, and gel-solution-gel transition experiments. All the results reveal that the crosslinked novolac epoxy resins based on DA reaction can be used as smart material for the practical application of electronic packaging and structural materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42167. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dially-based active ester (DAAE) was successfully synthesized via one-step esterification with a high yield and characterized. • DAAE was used as efficient hardeners to cure epoxy composite films (DAAE-ECFs) containing SiO 2 fillers. • DAAE-ECFs displayed low D k (∼3.0) and D f (∼0.005) values at high frequencies due to elimination of polar –OH groups in epoxy curing reaction, which maintained stable even in water. • DAAE-ECFs also demonstrated desirable thermal and mechanical properties. • DAAE-ECFs show great application potentials as advanced electronic packaging materials for 5G+communication techniques. Epoxy composites with ultralow dielectric dissipation factors (D f) are highly desired in advanced electronic packaging architectures to cater for high-frequency signal transmission. However, D f of epoxy systems traditionally cured by amine, anhydride or phenolic resin is too high due to the generated high-polarization groups like hydroxyl moieties. Using active esters as curing agents is an effective strategy to reduce polarization of cured epoxy by replacing hydroxyl moieties with ester groups. Herein, diallyl-based active ester hardeners (DAAE) are synthesized via one-step esterification reaction with a high yield of > 90 %. When DAAE is used to cure epoxy films containing SiO 2 fillers, the cured epoxy composite films (DAAE-ECFs) demonstrate low dielectric constant (D k , ∼3.0) and low D f (∼0.005) above 5 GHz at 25 ℃. Importantly, whether immersed in room-temperature water for 24 h or in boiling water for 1 h, DAAE-ECFs absorb < 0.6 wt% water with stable D k and slightly increased D f (<0.0085). Moreover, DAAE-ECFs show excellent thermal stability (T d5% >365 ℃), dimensional stability (CTE of ∼ 30 ppm ℃-1 below 80 ℃), high storage modulus (∼10 GPa at 30 ℃). The appealing dielectric, thermal and mechanical properties imply that DAAE-ECFs could serve as promising candidates for electronic packaging materials in high-frequency signal transmission. [ABSTRACT FROM AUTHOR]

Endowing electromagnetic interference (EMI) shielding foams with ultralow density and dynamic stable structure is crucial yet challenging. Here, we propose a facile one-step thermal treatment strategy to fabricate lightweight silver/reduced graphene oxide-coated carbonized melamine (CMF/rGO/Ag) hybrid foams with remarkable mechanical performance and outstanding EMI shielding effectiveness (EMI SE). Due to interfacial reinforcement of rGO between CMF skeleton and silver, the CMF/rGO/Ag foams show outstanding structural stability after 1000 cycles of a loading-unloading compression test. Moreover, The EMI SE of the foams reaches 50.6 dB at a mere density of 16 mg cm−3. The normalized surface-specific SE is up to 7616 dB cm2 g−1 with an ultralow Ag content of 0.09 vol%. Interestingly, the collaboration of the porous skeleton and multiple interfaces contribute to an anomalous high absorption coefficient of CMF/rGO/Ag foams (over 0.5). The high-absorption-coefficient shielding mechanism of the CMF/rGO/Ag foams was further studied by finite element analysis (FEA). The remarkable near-field EMI shielding performance of the CMF/rGO/Ag foam demonstrates that the low density and robust CMF/rGO/Ag foam have enormous advantages and wide application prospects as EMI shielding materials of electronic packaging. A silver/rGO coated carbonized melamine foam is fabricated by a one-step thermal treatment process. The as-prepared hybrid foams show excellent mechanical properties and structural stability. Due to the unique porous structure, the hybrid foams demonstrate an outstanding specific EMI SE of 7176 dB cm2 g-1, and an extra-high absorption coefficient of 0.51 with a low Ag content of 0.09 vol%. [Display omitted] [ABSTRACT FROM AUTHOR]

Epoxy composites with enhanced strength and toughness are vital in the field of electronic packaging material. This study proposes the synthesis of a novel lignin-based silicone-modified epoxy resin (LSE) to improve the strength and toughness of epoxy resins (EPs) simultaneously. The results demonstrate that the glass transition temperature, β -relaxation temperature, and crosslinking density of the composites decreased with increasing LSE content. Compared to neat EP, the toughness properties, including the impact strength and critical stress intensity factor (K 1C), of the 3 wt% LSE/EP composite improved by 16.25 % and 25.28 %, respectively. Meanwhile, the mechanical properties such as the tensile strength, bending modulus, and bending strength enhanced by 25.81 %, 16.21 %, and 42.43 %, respectively. Therefore, the LSE simultaneously exhibits toughening and strengthening effects. Based on the fracture surface evaluation results obtained using a scanning electron microscope and a nano-FTIR, these effects are attributed to the formation of interpenetrated networks and improved interfacial effects by the LSE. As an efficient fortifier and flexibilizer, LSE shows great promise for the preparation of EP packaging materials. [Display omitted] • A novel LSE flexibilizer was synthesized. • LSE showed good dispersion uniformity in epoxy resins. • The LSE/EP composite possessed excellent strength and toughness. [ABSTRACT FROM AUTHOR]

Hexagonal boron nitride (hBN) is an ultra-wide bandgap insulating material, which possesses a graphite-like layered structure, and the two-dimensional (2D) hexagonal boron nitride nanosheets (hBNNS), exfoliated from the bulk hBN, have promising applications in electronic packaging and high-power devices, due to the high thermal conductivity, excellent thermal/chemical stability as well as the ultra-wide band gap. However, the exfoliation of hBNNS is still a challenge with respect to high cost, time consuming, and low yield. Herein, a facile hydrothermal exfoliation method was proposed for the first time to exfoliate the hBNNS in a large yield and high concentration. In the optimized hydrothermal conditions, the lithium ion (Li+) intercalation, isopropanol (IPA) solvent, and the strong stirring could give rise to a large exfoliation yield up to ∼55% and a high concentration ∼4.13 mg/mL. In addition, the exfoliated hBNNS could enhance the methyl orange (MO) photodegradation efficiency of TiO 2 from 91% to 96.4 %. Most importantly, this hydrothermal exfoliation method could be a universal approach for the exfoliation of 2D materials. [ABSTRACT FROM AUTHOR]

Polyimides (PIs) have been extensively developed as interlayer dielectrics in electronic package industry due to their excellent comprehensive properties. However, the insufficient adhesion between PI and copper wires usually led to delamination and thus compromising the reliability of applications. In this work, a diamine monomer (SPMNH 2) that contained pyrimidine side groups and ether bonds was synthesized, and a series of its copolyimides (SPI) were prepared by copolycondensation with 2-(4-aminophenyl)-1H-benzimidazol-5-amine (APBI) and pyromellitic dianhydride (PMDA). The incorporation of pyrimidine rings, along with the presence of benzimidazole rings promoted the adhesion between PI and copper (1.3805 N/3 mm of SPI-4). In addition, a desired coefficient of thermal expansion (15.28 ppm/K of SPI-4) close to that of copper was obtained, facilitating the adhesion of the interface during high-temperature processes. Moreover, SPI-4 exhibited exceptional mechanical (the elongation at break of 44.02% and tensile strength of 191.64 MPa) and thermal properties (T g = 363.70 °C, T 5% = 519.33 °C). Therefore, the high-performance SPI films showed great potential in advanced packaging. [Display omitted] • A new molecular design strategy was proposed in constructing PI with high adhesion to copper. • The synthesized SPI showed good adhesion with smooth copper and the failure mode was found to be cohesive failure. • The new polyimide exhibited excellent mechanical properties, and a CTE (15.28 ppm/K) close to that of copper. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ultra-soft Ag@PDMS/silicone (APS) composites were successfully fabricated. • The compression capability of APS can be regulated by a modulus matching strategy. • The APS exhibits excellent EMI shielding and near-field shielding performance. Electrically conductive silicone composites have made significant advancements in the field of electromagnetic interference (EMI) shielding due to their excellent conductivity, elasticity, sealability and environmental reliability. Notably, chips and other miniature electronic components with limited pressure-bearing capacity often require composites with both low compressive stress and high EMI shielding performance. Unfortunately, conventional conductive silicone composites often exhibit high compressive stress as a result of the high modulus and high loading contents of fillers, which prevents them from fitting perfectly with the package cavity under low package stress conditions, resulting in inadequate EMI shielding. Herein, the elastic modulus of the silver@polydimethylsiloxane (Ag@PDMS) conductive filler can be adjusted by controlling the crosslinking ratio, which enables the creation-of-Ag@PDMS/Silicone-(APS)-conductive-composites-with-remarkable compressibility, EMI shielding and sealing capabilities. The-APS-composites exhibit a compressive stress of only 0.3 MPa under 50 % compressive strain, which is essential for the packaging-of-precision electronic components. The APS composites show a significant decrease in compressive stress (54 %) and elastic modulus (80 %) under 50 % compressive strain, in comparison to conventional polymer composites with hard fillers. Meanwhile, the APS composites exhibit a-satisfactory-EMI-shielding-effectiveness-(SE)-of-71-dB and demonstrate excellent electromagnetic sealing capabilities in practical electronics. This study provides an effective approach for developing and constructing high-performance ultra-soft composites for precision electronic components packaging. [ABSTRACT FROM AUTHOR]

Based on hard-sphere-like truncated Lennard-Jones interactions, a box compression simulation method, which belongs to molecular statics, was proposed to calculate the random close packing density of spherical particles. This method accurately provides the gradation corresponding to the maximum random close packing density with higher efficiency than the discrete element method (DEM). We trained an artificial neural network (ANN) model based on the data generated using this method to predict the packing densities of ternary and quaternary packing systems and discussed the applicability of this model in design of particulate-filled composites for electronic packaging. We found that the negative correlation between viscosity and random close packing density only applies to fillers of sizes greater than several microns. When the average filler size is reduced to submicron level, the specific surface area becomes the dominant factor in determining the upper limit of filler loading and viscosity of composites. [Display omitted] • Random close packing density of polydisperse spherical particles was calculated. • Isotropic virial pressure was applied during energy minimization for compression. • Random close packing density calculation efficiency is higher than DEM. • Developed model showed high prediction accuracy (R2 = 0.9876). • Model can be applied for designing particulate-filled composite materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • The intelligent VO 2 /cellulose nanofiber (VO 2 /CNF) composites were designed and fabricated successfully. • The lattice distortion across the phase transition of VO 2 induced by thermal stimuli changes EM parameters of composites. • The application of composites in control of the wireless transmission was demonstrated. Intelligent electromagnetic interference (EMI) shielding materials, which can generate reversible and real-time EM responses to external stimuli, have an attractive prospect in smart wearable electronics. Herein, we design and fabricate flexible and intelligent vanadium dioxide (VO 2)/cellulose nanofiber (CNF) shielding composites, showing a controllable EM response based on the reversible metal-to-insulator transition characteristic of VO 2 by thermal stimuli. With the phase transition of VO 2 between the insulating M phase and metallic R phase at ∼68 °C, the electrical conductivity of VO 2 /CNF composites is reversibly changed between ∼0.3 and ∼446.5 S/m, leading to a tunable shielding effectiveness (SE) between ∼18.7 and ∼52.8 dB in the frequency of 8.2–12.4 GHz. The lattice strain of VO 2 driven by thermal stimuli radically changes the EM parameters and impedance matching of VO 2 /CNF composites, which dominates the attenuation mechanism of EM waves. Uniquely, we demonstrate the VO 2 /CNF composites with a proof of concept to reversibly control the on and off of the wireless transmission. Moreover, the VO 2 /CNF composites exhibit an outstanding near-field shielding performance, which is potential to be applied in the electronic packaging field. This intelligent EMI shielding material has a broad prospect in the smart EM devices of next generation. [ABSTRACT FROM AUTHOR]

As electronic devices move toward miniaturization and high-degree integration, it becomes imperative to use nano-sized silica as a reinforcing filler for epoxy resin in modern electronics packaging industries. However, the use of silica nanoparticles (SNPs) brings about new challenges in filler dispersion and in the balance between the rheology and thermal mechanical performance of epoxy nanocomposites. This study presents a novel strategy aiming to address the above challenges by interface engineering with amino-rich branched polyethyleneimine (PEI) polymer molecules through a facile self-assembly process. This not only enables a considerable decrease (by 79.7%) in viscosity accompanied by a significant improvement in viscosity stability (only 2.7 times increase after 24 h) but also leads to a further CTE reduction of 4.8 ppm/°C (equivalent to the effects of around 10 wt% SNPs) relative to the SNPs. This work offers a new direction and efficient approach to develop high-performance epoxy composites for electrical packaging applications as well as provides some fresh insights into the interface-property relationships. Interfacial engineering by surface modification of silica nanoparticles (SNPs) with amino-rich branched polyethyleneimine (PEI) polymer molecules through a facile self-assembly process is developed to simultaneously improve the rheological and thermomechanical properties of SNPs/epoxy nanocomposites for electrical packaging applications. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • DOSS shows better adhesion to NiO, better ductility and self-healing compared to PDMS, making it good candidate as polymer matrix in TIM1 material. The reported outstanding adhesive and self-healing properties of a novel siloxane polymer – DOSS, have made it a promising candidate as polymer matrix of thermal interface materials (TIM). To explore its potential use in TIM, here we conduct systematic investigations on the interfacial properties of the DOSS/NiO interfaces at microscopic-scale using molecular dynamics (MD) simulations. MD can provide atomic-scale information which can hardly be obtained using experimental techniques. NiO presents at the surface of the plating layer of copper heat spreader in electronic packaging. DOSS is found to form rich hydrogen bonds with NiO, resulting in stronger adhesion to NiO compared to polydimethylsiloxane (PDMS), a conventional TIM matrix. The greater strength and ductility of DOSS compared to PDMS is ascribed to its rich hydrogen bonds and star-like topology. The strength changes with tensile rate, and is attributed to different strength and relaxation time of the bonded and non-bonded interactions. For ductility, an optimal temperature is found at 375 K. The DOSS has good self-healing ability, which is characterized by an 85% recovery of hydrogen bonds at 450 K. The microscopic insights provided by current work may shed lights on the design of DOSS as future potential polymer matrix to be used in TIM. [ABSTRACT FROM AUTHOR]