908 results about "Electronic packaging" patented technology

The invention relates to the technical field of electronic packaging, in particular to a welding process applied to a double-mesa device. The technology comprises the following steps that firstly, a heat conduction model of a double-table-board device is built, a temperature field prediction system is built in combination with measured data, secondly, an asymmetric double-pulse-current welding strategy is adopted, differential pulse waveforms are loaded to an upper table board and a lower table board respectively, independent temperature control over all welding areas is achieved, a temperature difference closed-loop feedback mechanism is introduced in the process, and the temperature field prediction system is obtained. Pulse parameters are dynamically adjusted according to real-time temperature deviation, a stress prediction and weld penetration monitoring module is used for assistance, the welding spot forming quality and heat stress balanced release are ensured, a staged annealing type cooling mode is adopted after welding, and the structural stability is improved. The method can be widely applied to MEMS modules, SiC power devices and heterogeneous chip laminated packaging double-mesa structure devices, and has the advantages of being high in welding precision, high in reliability and wide in process adaptability.

The invention provides a diode packaging defect tracing method and system based on correlation analysis, and relates to the technical field of electronic packaging process optimization and quality control. And extracting the frequency domain characteristic value of the X-ray image and carrying out correlation analysis in combination with the process parameters to determine a key abnormal process parameter combination causing the cavity defect. Therefore, the accuracy and reliability of defect tracing can be comprehensively improved, abnormal process parameters can be quickly positioned, and packaging process conditions can be optimized, so that the occurrence rate of cavity defects is effectively reduced, and the quality and performance of diode packaging are improved; the problem that root process parameters are difficult to accurately position due to cavity defects caused by mismatching of welding temperature and pressure can be solved to a certain extent.

The invention relates to a bionic Al / SiC composite material with a three-dimensional network multilevel structure and a preparation method of the bionic Al / SiC composite material, and belongs to the technical field of new material preparation. According to the method, through the collaborative process of freeze casting and organic foam impregnation, the problem that in the prior art, the multilevel aperture and the complex network structure are difficult to cooperatively regulate and control is solved. The preparation method comprises the following specific steps: preparing tert-butyl alcohol-based ceramic slurry, impregnating the slurry with polyurethane foam, performing freeze casting molding, removing a solvent through freeze drying, performing high-temperature sintering to form SiC ceramic with a three-dimensional reticular hierarchical pore structure, and finally preparing the Al / SiC composite material through a vacuum pressure infiltration process. Wherein a sintering aid is added into the slurry, so that the sintering temperature is obviously reduced; the specification (40-60 ppi) of polyurethane foam, the solid phase content (20-30 vol.%) of slurry, the freezing speed (0-90 DEG C) and the content (5-20 wt.%) of a sintering aid are regulated and controlled. And the cross-scale collaborative design of micron-scale directional holes and millimeter-scale mesh holes is realized. The Al / SiC composite material prepared by the invention has the advantages that the compressive strength, fracture toughness and other properties are obviously higher than those of the traditional single-aperture porous ceramic, and the Al / SiC composite material is suitable for the fields of manufacturing and energy absorption of precise instruments, electronic packaging and optical devices.

The invention relates to the technical field of high-temperature-resistant and high-thermal-conductivity epoxy electronic packaging adhesives, discloses a preparation method of a core-shell Al2O3-coated SiO2 filler and application of the core-shell Al2O3-coated SiO2 filler in epoxy packaging, and designs the preparation method of the core-shell structure filler Al2O3-coated SiO2 by chemically modifying the surface of the Al2O3 filler through high-temperature-resistant SiO2. The high-temperature-resistant SiO2 shell layer is modified on the surface of Al2O3, so that the interface wettability between the epoxy resin and the filler is promoted, the binding force between the filler and the epoxy resin is increased, the dispersity and fluidity of EMC are improved, meanwhile, the 175-DEG C bending strength of the epoxy resin is improved, and the high-temperature usability of the epoxy resin is greatly improved. And finally, the core-shell structure Al2O3-coated SiO2 can easily form a heat-conducting path among the filler, the interface and the matrix resin, so that the overall heat-conducting property of the composite material is improved, the low thermal expansion coefficient of the SiO2 shell layer is improved, the thermal stress is buffered, the temperature resistance is improved, and the core-shell structure Al2O3-coated SiO2 can be widely applied to packaging of semiconductor integrated circuits.

The invention discloses a preparation process of a high-performance Cu-Ni-Fe alloy calculated and designed based on a first principle, and relates to the technical field of alloy material preparation. According to the process, a precise Cu-Ni-Fe ternary alloy thermodynamic database is constructed by combining a first principle with a CALPHAD method, a multivariate phase diagram is calculated based on the database to determine a component range, then optimized components of a work function, an elastic constant and a thermal expansion coefficient are calculated through the first principle, and a finished product is obtained through smelting, heat treatment and forming machining. The final alloy is composed of, by atomic percent, 30%-75% of Cu, 10%-30% of Ni and 10%-30% of Fe, the tensile strength is larger than or equal to 816.4 MPa, the total elongation at break is larger than or equal to 34.27%, the thermal expansion coefficient is smaller than 20 * 10 <-6 > / K, the excellent mechanical property and thermal stability are achieved, the problems that component design is blind and performance fluctuation is large in a traditional process are solved, and the alloy is suitable for the fields of ocean engineering, electronic packaging and the like.

The invention relates to a preparation method of a magnetic field-electric field synergistically driven Fe3O4-loaded graphene three-dimensional interlocking network / metal composite material, and belongs to the field of electronic packaging materials. An alternating magnetic field and a direct-current electric field are applied in the solidification process of metal melt, Lorentz force is used for driving graphene nanosheets loaded with Fe3O4 to rotate directionally and be arranged vertically, meanwhile, the electric field induces dissociation of graphene edge functional groups, chemical bonding with a metal matrix is enhanced, and a space interlocking heat conduction network is formed. The graphene reinforced metal composite material is obviously superior to a traditional graphene reinforced metal composite material and is suitable for a heat dissipation substrate of aerospace electronic equipment.

The invention discloses a protruding conductive microsphere and a pretreatment method thereof. The pretreatment method specifically comprises the steps of roughening treatment, protruding and interface activity treatment, sensitization treatment, activating treatment and chemical plating. In the protruding and interfacial activity treatment, by adding an interfacial agent, the electronegativity of the surfaces of the microspheres is enhanced, electrostatic adsorption with positively charged nickel nanoparticles is generated, and meanwhile, agglomeration of the nickel nanoparticles on the surfaces of the polymer microspheres is effectively prevented through the steric hindrance effect; therefore, a nickel nanoparticle bulge structure which is high in density, uniform in distribution and firm in combination is formed on the surface of the polymer microsphere. The method effectively solves the problems that a traditional conductive microsphere coating is prone to cracking and falling off, poor in dispersity and the like, the prepared protruding conductive microspheres have the outstanding advantages of being high in coating binding force, excellent in conductivity, good in dispersity, not prone to agglomeration and the like, the technological process is simple, mass production is easily expanded, and the method is suitable for large-scale production. The anisotropic conductive adhesive film has a wide commercial application prospect in the field of electronic packaging such as anisotropic conductive adhesive films.

The invention discloses a nylon composite material and a preparation method thereof. The nylon composite material is prepared from polyamide, GF-POSS-1, GF-POSS-2, a toughening agent, an antioxidant and a lubricating agent. The GF-POSS-1 is obtained by reacting an aminated solid glass fiber and epoxidized POSS in a weight ratio of 5: (0.5-2); the GF-POSS-2 is obtained by reacting epoxidized hollow glass fibers and aminated POSS according to a weight ratio of 5: (0.5 to 2). The nylon composite material disclosed by the invention has excellent comprehensive properties of high tensile strength, high toughness, low dielectric constant and low dielectric loss, and is suitable for high-end scenes such as 5G communication and high-frequency electronic packaging.

The invention relates to the technical field of organic silicon materials, and discloses high-thermal-conductivity low-dielectric organic silica gel and a preparation method and application thereof.The high-thermal-conductivity low-dielectric organic silica gel is prepared from a component A and a component B. The component A is prepared from, by weight, 35-45 parts of vinyl polysiloxane, 40-50 parts of vinyl silicone resin, 5-20 parts of modified boron nitride, 0.75-1.25 parts of a flatting agent, 1.5-2.5 parts of a defoaming agent and 0.05-0.15 part of a platinum catalyst; and the component B comprises the following components in parts by weight: 15-20 parts of vinyl polysiloxane, 60-85 parts of hydrogen-containing silicone oil and 0.05-0.15 part of an inhibitor. According to the scheme, a continuous and effective 3D heat conduction network is constructed through modified boron nitride, the heat conduction performance of the organic silica gel is improved, meanwhile, covalent interaction is formed between the modified boron nitride and other matrixes, interface bonding is high, the dipole polarization effect at an interface is reduced, the dielectric constant is reduced, and the organic silica gel is quite suitable for the field of electronic packaging.

The invention relates to the field of low dielectric materials, and particularly discloses a BCB-containing fluorene derivative as well as a preparation method and application thereof, and the derivative is specifically shown as follows: in substitution sites 1-10 of fluorene and / or fluorene derivative, substituent groups R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 are independently selected from at least one of hydrogen atoms, alkyl groups and aryl groups, and the substituent groups R9 and R10 comprise at least one BCB group. According to the present invention, the BCB group is introduced to the R9 and / or R10 substituent group of the fluorene and / or the fluorene derivative, such that the obtained BCB-containing fluorene derivative has characteristics of good thermal stability and low dielectric property. Meanwhile, the performance of the fluorene derivative containing BCB can be accurately optimized by flexibly regulating and controlling the types of substituent groups, the number of BCB groups on R9 and R10 substituent groups and the structure of the substituent group on the fluorenyl group, so that the problem of meeting low dielectric materials in the fields of high-performance PCBs, electronic packaging and the like in the prior art is solved.

The invention relates to the technical field of electronic packaging materials, in particular to a phthalonitrile modified thermosetting resin composition containing a siloxane structure and application of the phthalonitrile modified thermosetting resin composition in the electronic packaging materials. The composition comprises multifunctional epoxy resin, XYLOK phenolic resin, a curing accelerator, a modifier and an inorganic filler, and the modifying agent is eugenol phthalonitrile trisiloxane. The modifier disclosed by the invention has good mechanical compatibility and dispersity in matrix resin; when the epoxy resin is applied to a thermosetting resin system, the processability can be improved, and the toughness of a cured product can be effectively improved while the glass-transition temperature is increased, so that the cured product has excellent bending property; the composition has excellent thermal stability, low bending modulus, good impact performance and humidity and heat resistance after being cured, the glass transition temperature of the composition is effectively improved, the comprehensive performance of resin is remarkably improved, and the composition is suitable for improving the packaging reliability and environmental stability of semiconductor devices.

The invention belongs to the technical field of electronic packaging and welding materials, and relates to lead-free solder powder for reflow soldering and a preparation method of the lead-free solder powder. The lead-free solder powder is based on a Sn-Ag-Cu alloy system, and melt purification, beta-Sn grain refinement and interface IMC stabilization are achieved by compositely adding trace Ce and Ni elements. The Sn-Cu-Ce alloy comprises the following components in percentage by mass: 2.9%-3.1% of Ag, 0.45%-0.55% of Cu, 0.01%-0.10% of Ce, 0.01%-0.05% of Ni and the balance of Sn and impurities. During preparation, a Ce-Ni intermediate alloy is adopted to introduce microalloy elements, and the spherical solder powder is obtained through vacuum melting, inert gas atomization and surface treatment. The obtained solder powder is low in oxygen content, good in wettability, slow in interface IMC growth after backflow, high in welding spot strength and excellent in thermal cycle reliability, and is suitable for the field of high-reliability electronic packaging.

The invention discloses a single-component high-heat-resistance type epoxy adhesive and a preparation method of the single-component high-heat-resistance type epoxy adhesive. The adhesive is prepared from the following components in parts by weight: 30 to 40 parts of N, N-4, 4 '-diphenylmethane bismaleimide; 50 parts of bisphenol F epoxy resin; 36.47 parts of 4, 4 '-diaminodiphenyl sulfone; 20 to 40 phr of phenyl glycidyl ether; 1 to 2 phr of two terminal type epoxy silicone oil; 4 to 6 phr of hydroxyl-terminated polyether sulfone; 10 to 20 phr of boron nitride, the surface of which is modified by gamma-glycidyl ether oxypropyl trimethoxy silane; and 1 to 3 phr of an adhesion promoter. According to the adhesive disclosed by the invention, the heat resistance, the mechanical property, the dimensional stability, the process adaptability and the like are synergistically improved, the use requirements of an aviation structural part on long-term service at 150-180 DEG C and an electronic packaging device on the condition of short-time reflow soldering at about 200 DEG C can be met, and the reliability of the adhesive in a high-temperature environment is remarkably improved.

The invention discloses a liquid molding compound for eliminating flow marks and a method and application thereof, and relates to the technical field of electronic packaging materials, the liquid molding compound comprises the following components by mass: 85%-90% of silicon dioxide, 4%-8% of epoxy resin, 5%-8% of an anhydride curing agent, 0.2%-0.5% of organic pregel microparticles, 0.2%-0.3% of a catalyst, and 0.1%-0.2% of carbon black, the maximum particle size of the silicon dioxide is less than 75 microns, and the particle size distribution of the silicon dioxide is as follows: 1.4 microns < = D10 < = 1.6 microns, 12 microns < = D50 < = 18 microns, and 40 microns < = D90 < = 50 microns. The flow mark of the liquid molding compound is improved by adopting the silicon dioxide with different particle size distribution, the catalyst formed by compounding the silicon dioxide and the organic pre-gel microparticles, so that the liquid molding compound has no flow mark after being packaged and cured, and the comprehensive performance and the production yield of a packaged device are improved.

The invention provides a drilling processing method for a ceramic substrate. The drilling processing method for the ceramic substrate comprises the following steps: forming a large hole in the ceramic substrate by adopting laser drilling, wherein the aperture of the large hole is 0.25-5mm or is 0.5 times greater than the thickness of the ceramic substrate; filling the macropores with a composite material containing a ceramic filler and thermosetting resin, and forming a supporting layer through a curing process; and the supporting layer is mechanically drilled to form small holes, and the hole diameter of the small holes is smaller than that of the large holes. According to the ceramic substrate drilling machining method, through stepped drilling of laser taper hole guiding, composite material filling and mechanical precision drilling, the problem that small holes of a thin substrate are prone to cracking during machining is solved, the yield is increased, the risk of breakage of a hard drill bit for mechanical drilling can be reduced, machining time is shortened, and the production cost is reduced; the drilling processing method is compatible with various ceramic substrates, and can solve the problem of multi-material integration of electronic packaging.

The invention belongs to the technical field of electronic packaging carrier plates, and discloses an ultrathin diamond carrier plate and a preparation method and application thereof.The preparation method comprises the steps that a heterogeneous substrate is selected, cleaned and subjected to seed crystal, and then a sacrificial layer is introduced; growing a compact and continuous ultrathin diamond film on the substrate pretreated in the step 1 through chemical vapor deposition; sequentially carrying out surface cleaning, activation and modification on the diamond film; constructing a metal layer structure required by conductive wiring and a heat dissipation substrate on the surface of the diamond carrier plate; the ultrathin diamond film deposited on the heterogeneous substrate is separated from the substrate, and a self-supporting diamond carrier plate is obtained; the heat-conducting property of the packaging substrate is remarkably improved, and an ultrathin structure with controllable thickness can be prepared; a reliable diamond film heterogeneous substrate growth and stripping process is provided, so that an independent support plate can be conveniently obtained from a growth substrate by the thin film; the metallization adhesive force of the surface of the carrier plate is enhanced, high-density circuit patterning on the surface of the substrate is supported, and the packaging reliability is improved.

The invention discloses a high-temperature-resistant bismaleimide resin and a preparation method thereof. Comprising nadic anhydride terminated polyimide resin containing a methyl ethyl asymmetric side chain, bismaleimide resin, cyanate ester resin and a toughening and chain extending component. The preparation method comprises the following steps: adding the bismaleimide monomer into the allyl bisphenol A, then adding the reactive diluent, the polyimide resin and the toughening component, and heating and prepolymerizing to obtain the high-temperature-resistant bismaleimide resin. The crosslinking network density and dielectric property of the resin are improved through the reaction of reactive nadic anhydride and bismaleimide resin and the reaction of bismaleimide and cyanate ester resin, and the solubility of the high-temperature-resistant bismaleimide resin in a low-boiling-point solvent is improved through the molecular structure design of polyimide, so that the high-temperature-resistant bismaleimide resin is prepared. The toughness and high temperature resistance of the bismaleimide resin are improved, the size stability of the bismaleimide resin is good, and the application potential of the bismaleimide resin in the fields of aerospace, copper-clad plates, advanced electronic packaging, mechano-electronics and the like is improved.

The invention relates to the technical field of electronic packaging materials, in particular to a thermosetting resin composition for packaging a high-reliability semiconductor device. The composition comprises multifunctional epoxy resin, XYLOK phenolic resin, a curing accelerator, a modifier and an inorganic filler, and the modifying agent is eugenol phthalonitrile polysiloxane. The modifier has good mechanical compatibility and dispersity in matrix resin; and when being applied to a thermosetting resin system, the epoxy resin can improve the processability and effectively enhance the toughness of a cured product. The composition provided by the invention accords with the processing and forming process of the existing epoxy molding compound; according to the present invention, the spiral flow length of the molding compound is substantially increased, the processing performance is good, the cured product has advantages of good thermal stability, low bending modulus, good impact property and good heat and humidity resistance, and the glass transition temperature is increased. The resin is significantly improved in comprehensive performance, and is suitable for packaging semiconductor devices with high requirements on reliability and environmental stability.

The invention discloses low-silver-content composite conductive silver paste based on a three-dimensional conductive network and a preparation method, and relates to the technical field of composite conductive silver paste preparation, and the low-silver-content composite conductive silver paste comprises a low-silver-content conductive phase, an interface bonding layer, a support body and an organic carrier; and the conductive phase with low silver content comprises the following components: 25 wt%-30 wt% of silver-plated hollow glass beads and 12 wt%-18 wt% of a three-dimensional conductive network. According to the invention, through accurate proportioning of the conductive phase with low silver content, the use amount of silver is greatly reduced. The silver-plated hollow glass bead takes light glass as a core and an ultrathin silver layer as a conductive shell, so that the silver consumption is reduced by more than 60wt%; the three-dimensional conductive network adopts a synergistic structure of silver nanowire fragments and graphene composite fragments, and the high conductivity of graphene is utilized to replace part of silver materials, so that the dependency degree of silver is further reduced. The silver content of the silver paste is greatly reduced, the cost of raw materials is greatly reduced, and the economical efficiency of the silver paste in large-scale application scenes such as photovoltaic and electronic packaging is remarkably improved.

The invention discloses a hyperbranched flame retardant as well as a preparation method and application thereof. The flame retardant is prepared by the following steps: dehydrating and pre-polymerizing a boron-containing component (such as tetrahydroxy diborane) and dihydric alcohol (such as 1, 3-propylene glycol), and condensing with trihydroxymethyl phosphine oxide. 4 parts of the flame retardant is added into epoxy resin, phosphorus-containing free radicals can be released in a gas phase for quenching and smoke suppression, a compact boron-containing expanded carbon layer is formed in a condensed phase, and synergistic flame retardance is achieved. The hyperbranched structure can be embedded into an epoxy network, synchronous reinforcement and toughening are achieved, the impact strength is improved by 123.5%, and the tensile strength is improved by 47.7%. The flame retardant has efficient flame retardance (the limit oxygen index is 33.9%, UL-94V-0 level), high transparency and excellent mechanical properties, and is suitable for epoxy resin composite materials in the fields of electronic packaging, aerospace and the like.

The present application relates to the technical field of adhesive, and particularly relates to a high-thermal-conductivity adhesive for electronic packaging and a preparation method thereof.The high-thermal-conductivity adhesive for electronic packaging comprises, by weight fraction, 55-60 parts of acrylate monomer, 40-45 parts of methacrylate monomer, 0.5-5 parts of photoinitiator, 10-25 parts of modified boron nitride, 1-3 parts of thixotropic agent, 0.2-1 part of defoaming agent and 0.5-1 part of antioxidant.The present application introduces the methacrylate monomer with a novel structure into the adhesive, endows the adhesive with excellent hydrolysis resistance, effectively reduces the volume shrinkage rate of the adhesive, and improves the thermal conductivity of the adhesive.In addition, the modified boron nitride introduced into the adhesive can avoid the agglomeration of boron nitride, improve the dispersibility and compatibility of the boron nitride, and further improve the thermal conductivity of the adhesive.

The invention relates to the field of hydrophilic thermosensitive resin, in particular to hydrophilic thermosensitive resin as well as a preparation method and application thereof, and aims to solve the problems that an existing thermosensitive material is insufficient in hydrophilicity, an existing hydrophilic material is insufficient in thermosensitive performance, and a resin material cannot give consideration to both the hydrophilic material and the hydrophilic material at the same time. According to the resin, an imidazole structure is introduced into polyacrylamide and grafted into PNIPAM to form an amido bond, the hydrophilic performance of the PNIPAM is improved, ethyl cellulose is grafted onto amino-treated silicon dioxide to form an amido bond, and the hydrophilic performance of the resin is improved together with modified polyacrylamide blended PNIPAM; when the resin is applied to a specific medium or environment, the resin can show a corresponding response behavior on absorption or release of moisture according to the change of environment temperature, realizes effective regulation and control and induction on temperature and humidity, and can be applied to temperature-sensitive medical treatment, electronic packaging and other emerging technical fields.

The invention belongs to the field of microelectronic packaging, and discloses an integrated chip near-node diamond micro-channel heat dissipation packaging structure and a preparation method thereof.The integrated chip near-node diamond micro-channel heat dissipation packaging structure comprises an electrical interconnection structure, a 3D integrated chip and a heat dissipation module which are stacked in sequence, and the electrical interconnection structure is connected with the 3D integrated chip through a contact of the 3D integrated chip; the heat dissipation module comprises a heterogeneous bonding layer, a diamond substrate, a metal circuit layer and a copper-based diamond micro-channel layer which are stacked in sequence, and the heterogeneous bonding layer is in contact with one surface, close to the node side, of the 3D integrated chip; a micro-channel structure is arranged in the copper-based diamond micro-channel layer; and the micro-channel structure is filled with liquid metal. The heat dissipation module is arranged on the side, close to the node, of the 3D integrated chip, and based on the design of the high-heat-conductivity heat dissipation material and the heat dissipation structure in the heat dissipation module, the effect that the compatible heat dissipation efficiency of the 3D integrated chip is improved and the 3D integrated chip is convenient to use can be achieved by integrally manufacturing the micro-channel structure.

The invention discloses a low-corrosion halogen-free soldering flux for aluminum-based part brazing and a preparation method of the low-corrosion halogen-free soldering flux, and belongs to the technical field of halogen-free welding materials.The low-corrosion halogen-free soldering flux comprises, by mass, 4-6 parts of oxalic acid, 1-2 parts of triethanolamine, 0.8-1.5 parts of Tween-80, 4-6 parts of polyvinylpyrrolidone, 0.3-1 part of compound nano cerium oxide, 0.5-1.5 parts of chitosan oligomer and the balance deionized water. And the welding spot oxidation resistance and the interface self-repairing capability are further improved. Through the synergistic effect of four mechanisms of complexing, oxidation prevention, wetting and film forming, the flux achieves efficient film removal, excellent wetting, no corrosion residue and stable film forming protection, is high in shear strength, low in welding spot porosity and clean in surface after welding, and is suitable for electronic packaging, heat exchanger manufacturing and high-reliability aluminum welding occasions.

The invention discloses a high-weldability modified TPU film and a preparation method thereof, and belongs to the technical field of high polymer material modification. The film comprises the following components: 100 parts by weight of TPU resin; 1-5 parts by weight of a filler with a particle size of 1-5 [mu] m after surface treatment; 0.5 to 1.2 parts by weight of an antioxidant; wherein the filler subjected to surface treatment is obtained by cleaning a filler raw material with an oxalic acid solution and coating the filler raw material with a titanate coupling agent for surface treatment. The filler subjected to surface treatment is added, and an optimized melt extrusion process is combined, so that the welding strength of the film is remarkably improved, the heat sealing stripping force is greatly improved, and the problem that a welding surface is easy to crack is thoroughly solved; meanwhile, the intrinsic performance of TPU is perfectly reserved, the elongation at break is maintained, the transparency decrease amplitude is small, the thermal aging resistance is excellent, and the double requirements for high-strength welding and flexibility maintaining in the fields of automobile sealing parts, electronic packaging and the like are completely met.

An electronic device is disclosed. The electronic device includes a die-attach pad, a semiconductor transistor having: a top surface positioned opposite of a bottom surface; a gate terminal and a source terminal disposed at the top surface; a drain terminal disposed at the bottom surface, a first lead separate from the die-attach pad and including a base, the base electrically and mechanically connected to the die-attach pad, a second lead separate from the die-attach pad and electrically isolated from the die-attach pad, the second lead electrically connected to the gate terminal, and a third lead separate from the die-attach pad and electrically isolated from the die-attach pad, the third lead electrically connected to the source terminal, and an electrically insulative encapsulant at least partially encapsulating the die-attach pad, the semiconductor transistor, the first lead, the second lead and the third lead.

The invention discloses a preparation method of high-purity aluminum nitride single crystal powder. The method comprises the following steps: uniformly mixing raw materials aluminum powder and aluminum nitride powder according to a ratio, putting the mixture into an air pressure sintering furnace, vacuumizing, introducing high-pressure argon, heating to a set temperature, introducing nitrogen, carrying out a fire blast reaction, cooling to room temperature, and crushing to obtain the high-purity aluminum nitride single crystal powder with D50 of 20-200 microns. According to the method, the synthesis of the coarse-particle high-purity aluminum nitride single crystal powder is realized by utilizing the rapid nitridation explosion reaction of the aluminum powder in the high-temperature and high-pressure nitrogen, the method has the characteristics of simple process and low preparation cost, and the prepared high-purity aluminum nitride single crystal powder can be used as a high-thermal-conductivity filler for electronic packaging.

The invention discloses a method for predicting hydrogen diffusion of a multi-coating material on the surface of a material in a vacuum environment, and belongs to the technical field of hydrogen diffusion of materials. On the basis of a hydrogen atom diffusion mass transfer theory in a single-layer matrix material, a hydrogen atom diffusion mass transfer model of the double-coating material is constructed. The hydrogen atom diffusion differential equation, the capture / removal differential equation and the boundary desorption / adsorption differential equation of the single-layer matrix material are established in combination with respective material parameters corresponding to different materials of each layer, boundary condition parameters are introduced into an interlayer interface, the flux continuity and concentration transition relation between the matrix and the plating layer is processed, and the plating layer is obtained. And further obtaining the hydrogen concentration distribution and the dynamic hydrogen release rate in the multi-coating material. The prediction method disclosed by the invention is suitable for any coating combination, can quickly migrate only by replacing material data, and is suitable for multiple fields such as electronic packaging, vacuum devices, hydrogen fuel cells and the like.

The invention relates to the technical field of computer simulation, in particular to a loss stress simulation analysis method for an electronic packaging curing agent. The method comprises the following steps: acquiring physical and chemical parameters and mechanical property data corresponding to the electronic packaging curing agent to generate a packaging curing agent basic performance data set; generating curing agent microstructure evolution data based on the packaging curing agent basic performance data set, and performing stressor identification and packaging stress field distribution mapping to obtain packaging structure stress field initial distribution data; performing stress evolution simulation under a temperature cyclic load according to the initial distribution data of the stress field of the packaging structure, and calculating a loss factor and a stress relaxation coefficient corresponding to an electronic packaging curing agent to obtain a curing agent loss stress characteristic parameter; and acquiring a humidity aging factor, performing influence dynamic evaluation, and generating a curing agent loss stress life evaluation report. According to the invention, the precise simulation process of curing agent loss and stress distribution in the electronic packaging process can be realized.

The invention discloses a preparation method of environment-friendly epoxy polystyrene foam with controllable foaming ratio. A foaming agent and a surfactant are premixed to form an activation system with the Zeta potential larger than or equal to 30 mV, then the activation system is mixed with an epoxy resin matrix in stages, and the epoxy polystyrene foam is prepared by combining the delayed curing agent adding time and the vacuum defoaming technology. The foaming ratio is accurately controlled by 3-5 times, the foam size is 50-200 [mu] m, meanwhile, the VOCs emission is smaller than or equal to 50 [mu] g / g, the curing time is 1-3 h, and the bonding strength is larger than or equal to 12 MPa. The adhesive is suitable for high-performance light-weight bonding requirements in the fields of electronic packaging, automobile manufacturing and the like.