1373 results about "Electronic packaging" patented technology

The invention discloses a preparation method and application of a vertically-oriented boron nitride / epoxy resin heat-conducting composite material under a magnetic field, and belongs to the field of composite materials. The invention aims to solve the problems of high cost, complex process and narrow application range of the existing filler directional arrangement method. The method comprises the following steps: 1, preparing a mixed solution of boron nitride and ferroferric oxide; 2, preparing a boron nitride nanosheet solution with ferroferric oxide attached to the surface; (3) preparing BNNS coated Fe3O4; and 4, preparing the vertically-oriented boron nitride / epoxy resin heat-conducting composite material under the magnetic field. The invention relates to application of a vertically-oriented boron nitride / epoxy resin heat-conducting composite material in electronic packaging under a magnetic field. The heat conductivity of the epoxy resin can be effectively improved, the process is simple and reliable, the efficiency is high, the cost is low, the heat conductivity coefficient is high, and the method can be applied to electronic packaging.

The present disclosure relates to circuit package implementations. The circuit package includes a PIC that allows for the transmission of data photonically between hardware coupled to the PIC. The circuit package further includes one or more spacers that are positioned above the PIC in a manner that allows light to pass through an optical path between the top surface of the circuit package and the PIC. Different spacers can be added to the package at different stages of the manufacturing process such that the optical path is maintained through the manufacturing of the circuit package. The circuit package having the optically accessible PIC may be implemented within the framework of a microelectronic package.

The invention relates to the technical field of microelectronic packaging, and discloses a packaging method of a multi-layer stacked memory chip, which comprises the following steps: constructing a 3D packaging structure layout of a memory chip to be packaged; constructing a physical field of the 3D packaging structure layout, and integrating the physical field and the field action relationship into the 3D packaging structure layout to obtain a coupled 3D packaging structure layout; calculating a hot spot, a high stress area and a high electric field area of the coupled 3D packaging structure layout, and optimizing the coupled 3D packaging structure layout to obtain a target packaging structure layout; performing multi-layer stacking on the to-be-packaged storage chip to obtain a multi-layer stacked storage chip; and packaging the multi-layer stacked memory chip to obtain a packaged multi-layer stacked memory chip, activating packaging repair of the self-repair material by using a preset material repair algorithm to obtain a packaging repair material, and performing multi-layer stacked packaging of the to-be-packaged memory chip based on the packaging repair material. According to the invention, the packaging stability of the multi-layer stacked storage chip can be improved.

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 belongs to the technical field of metal powder preparation, and discloses a method for preparing silver powder through reduction of hydrazine hydrate with the adjustable particle size. The preparation method comprises the following steps that a first dispersing agent is dissolved in deionized water, a silver-ammonia solution and a hydrazine hydrate solution are sequentially added, stirring reaction is conducted, and nano-silver seed crystal sol is obtained; uniformly mixing the obtained nano-silver seed crystal sol with a hydrazine hydrate solution and a second dispersing agent to obtain a reducing base solution; adding a surface modifier into absolute ethyl alcohol, and uniformly dissolving to obtain a surface modification coating solution; preparing a silver-ammonia solution, adding the prepared silver-ammonia solution into the reducing base solution, then adding the surface modification coating solution, and stirring for reaction to obtain silver powder slurry liquid; and after solid-liquid separation, a solid phase is taken, washed and dried, and silver powder is obtained. The preparation method is simple in process, the particle size of the silver powder can be adjusted through the adding amount of the seed crystal, and the prepared silver powder particles are uniform in particle size distribution, high in dispersity and suitable for the fields of conductive silver paste, electronic packaging and the like.

The present disclosure relates to circuit package implementations. The circuit package includes a PIC that allows for the transmission of data photonically between hardware coupled to the PIC. The circuit package further includes one or more spacers that are positioned above the PIC in a manner that allows light to pass through an optical path between the top surface of the circuit package and the PIC. Different spacers can be added to the package at different stages of the manufacturing process such that the optical path is maintained through the manufacturing of the circuit package. The circuit package having the optically accessible PIC may be implemented within the framework of a microelectronic package.

The invention discloses an electronic packaging heat dissipation substrate and a processing technology and application thereof. The electronic packaging heat dissipation substrate comprises a copper-clad diamond copper plate, a diamond sheet located on the copper-clad diamond copper plate and a first copper layer covering the diamond sheet. The copper-clad diamond copper plate comprises a diamond copper core material and a copper layer located on the surface of the diamond copper core material. The diamond copper core material and the copper layer form a composite board with a copper layer-core material-copper layer sandwich structure; and the copper-clad diamond copper plate, the diamond sheet and the first copper layer are connected into a whole through brazing. According to the electronic packaging heat dissipation substrate, the peeling and cracking risks can be reduced, and the problem of low heat transfer efficiency is solved.

The invention relates to the technical field of electronic packaging, and discloses an intelligent dispensing control method and system based on machine vision and a storage medium. The method comprises the following steps: acquiring a dispensing part image, and performing feature extraction on the dispensing part image to obtain feature information; according to the feature information, carrying out dispensing position area calculation to obtain the area of a dispensing area; calculating the surface roughness of the dispensing part according to the feature information of the image to obtain roughness information; according to the feature information, the dispensing position and the roughness information, the dispensing amount is calculated, and dispensing parameters are obtained; according to the dispensing parameters and the roughness information, the dispensing amount is adjusted, and the effective dispensing amount is obtained; according to the dispensing parameters, the effective dispensing amount and the dispensing area, dispensing operation is carried out, and a dispensing result is obtained; and according to the dispensing result, the dispensing quality is monitored and adjusted based on visual feedback control. According to the method, the dispensing precision of the dispensing machine can be improved, parameters are optimized, and efficient dispensing control is achieved.

The invention discloses a production quality evaluation method for a gold bonding wire, and relates to the technical field of microelectronic packaging, and the method comprises the following steps: obtaining a surface image of the gold bonding wire through a high-resolution image collection system; performing preprocessing on the image data based on the acquired image to eliminate noise and enhance contrast; through the image data, extracting surface topography gradient features by using morphological operation, and quantifying microstructure changes of the surface of the gold wire; extracting texture energy characteristics through wavelet multi-scale decomposition, and analyzing distribution characteristics of surface textures from different scales; self-adaptive fusion is carried out on the morphological gradient features and the texture energy features, and the feature expression of the defect area is enhanced by dynamically adjusting the weight; dividing the boundary of a defect region by adopting an adaptive threshold segmentation method, and separating a normal region from an abnormal region; and extracting geometric and textural features of the defect region obtained by segmentation, realizing automatic discrimination of defect types through a classification model, and outputting a quality evaluation result.

The invention relates to the technical field of electronic packaging, and discloses a method for controlling welding of a welding hole plug-in by using a prefabricated welding flux, and the method comprises the following steps: S1, dehumidifying and drying: drying a substrate by using a drying oven; s2, a solder column is manufactured, specifically, based on an original welding hole site in the substrate to be welded, the soldering tin amount Vt between the welding hole site and the plug-in is calculated, the size of the solder column is calculated according to the value of the soldering tin amount Vt, and the solder column is manufactured; s3, welding preparation is conducted, specifically, the plug-in, the substrate and the welding flux column are sequentially installed on the clamp body; and S4, reflow soldering. The soldering tin amount is calculated according to the size of a welding hole site needing to be welded and the size of a plug-in, a solid solder column of a fixed mass is manufactured in advance through the calculated soldering tin amount, the soldering tin amount is accurately controlled so as to accurately fill a weld joint, the situation that tin is too much or too little after welding is avoided, the welding quality is improved, and meanwhile the welding quality is improved. During welding, the amount of solder paste does not need to be controlled, and the efficiency can be greatly improved by directly using the solder column and placing the solder column on the plug-in.

The invention relates to a low-temperature curing polyimide precursor solution and a preparation method thereof. The method comprises the following steps: carrying out condensation polymerization reaction on a dianhydride monomer and a diamine monomer in a reaction solvent to obtain a polyamide acid solution; and adding an amino compound containing one or more special functional groups of pyridine, imidazole, quinoline, pyrimidine and azine into the polyamide acid solution, and fully stirring to enable amino in the compound to fully react with carboxyl in a polyamide acid molecular chain, thereby obtaining the polyimide precursor solution capable of being cured at low temperature. According to the preparation method, the curing temperature of polyimide can be greatly reduced, meanwhile, the mechanical property of the material can be improved, the thermal expansion coefficient can be reduced, and the preparation method can be used for preparing polyimide binders, photoresist, electronic packaging, resin, films, fibers and aerogel.

The invention provides a graphene-boron nitride composite epoxy resin material and a preparation method thereof, the surface of a graphene-boron nitride filler is modified to obtain a filler with magnetic response, the filler is added into epoxy resin, and the filler can be in more sufficient contact and ordered arrangement under the action of an external magnetic field, so that the graphene-boron nitride composite epoxy resin material is obtained. The heat conductivity coefficient of the composite material is effectively improved. Tests show that when the filler accounts for 25%, the heat conductivity coefficient reaches 2.1 (W / mk), and the friction coefficient can be effectively reduced and is reduced by about 30% compared with pure epoxy resin. The research of the invention provides a new thought and method for preparing the epoxy resin-based composite material with high heat-conducting property, expands a new field and direction for the application of epoxy resin in the field of electronic packaging, and has practical significance.

The invention discloses a method for preparing regenerated flame-retardant high-shrinkage polyester by a methanol alcoholysis method, and belongs to the technical field of polyester. The method comprises the following steps: (a) mixing the waste polyester fabric with methanol, and carrying out catalytic depolymerization to obtain a regenerated DMT mixed solution; (b) carrying out impurity separation and methanol recovery treatment on the regenerated DMT mixed solution, and then carrying out cooling crystallization, centrifugal drying and rectification purification treatment to obtain pure DMT; (c) carrying out transesterification on pure DMT, ethylene glycol, a transesterification catalyst and a DEG inhibitor; (d) after the ester exchange reaction, adding CEPPA-EG and IPA-EG for copolymerization; adding a polymerization catalyst, a stabilizer and an antioxidant for polymerization reaction to obtain a modified polyester melt; and (e) granulating and drying to obtain the slices. The regenerated polyester prepared by the method has multiple functions of flame retardance, high boiling water shrinkage, low-temperature dyeing and the like, and is suitable for the fields of high-end clothing, automotive trim, electronic packaging materials and the like.

A microelectronics package comprises a substrate comprising at least two conductive layers that are separated by a first dielectric. At least one island comprising a magnetic material is embedded within the dielectric between the two conductive layers. An inductor structure extends within a via in the at least one island. The via extends between the two conductive layers. The inductor structure comprises a conductive wall along a sidewall of the via, and wherein the conductive wall surrounds a second dielectric and is electrically coupled to the two conductive layers.

The invention provides a preparation method of an MXene (at) BN heterostructure heat-conducting filler and an epoxy composite material thereof, boron nitride and MXene nanosheets are respectively modified by cation and anion modifiers, and the heterostructure filler is constructed by electrostatic self-assembly. When the filler is applied to epoxy resin, the prepared MXene-coated BN / epoxy composite material shows excellent heat conductivity and electrical insulating property. The method provided by the invention is simple and efficient in preparation process, is suitable for large-scale industrial production, can realize the balance of high thermal conductivity and excellent electrical insulation property under low filler load, and provides an innovative efficient heat dissipation solution for the field of electronic packaging.

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 belongs to the technical field of adhesive preparation, and particularly relates to a flexible epoxy adhesive modified organic silicon adhesive and a preparation method and application thereof.The flexible epoxy adhesive modified organic silicon adhesive is composed of a component A and a component B, the component A is prepared from 40-70 parts of vinyl-terminated silicone oil, 10-30 parts of hydrogen-containing silicone oil, 5-20 parts of filler, 1-5 parts of coupling agent and 1-10 parts of curing agent; and the component B comprises the following components in parts by weight: 60-70 parts of vinyl-terminated silicone oil, 5-20 parts of epoxy resin, 5-15 parts of a platinum catalyst, 1-5 parts of an accelerant, 1-5 parts of an inhibitor and 5-20 parts of filler. Epoxy resin is introduced into an organic silicon matrix and is matched with a toughening agent and a catalyst, so that efficient combination of a two-phase system is realized, and the adhesive which is stable in performance, high in adhesive force and excellent in flexibility is obtained and has excellent comprehensive performance and application prospects in electronic packaging, automobile part bonding and building sealing.

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 provides a polyimide-based dielectric heat-conducting composite material and a preparation method thereof.The preparation method comprises the steps that a hexagonal boron nitride nanosheet is modified through polydopamine to obtain a modified boron nitride nanosheet (MBN), and the modified boron nitride nanosheet (MBN) is mixed with a polyamide acid (PAA) solution to obtain an MBN / PAA solution; mBN is directionally distributed in PAA nanofibers through an electrostatic spinning technology, meanwhile, dispersion liquid of silver wires is electrostatically sprayed, and the silver wires serve as a bridge, so that a heat conduction path is constructed under the condition that less filler is doped; finally, the MBN-AgNW / PI dielectric heat-conducting composite material is prepared through a staggered stacking-compression molding-thermal imidization technology, and the prepared composite material is good in heat conductivity, low in dielectricity and high in insulativity and has huge application potential in electronic packaging equipment.

The invention relates to the technical field of flame-retardant materials, and particularly discloses a graphene-modified flame-retardant polyurethane material and a preparation method thereof.The graphene-modified flame-retardant polyurethane material is prepared from, by weight, 60-70 parts of polyhydric alcohols, 30-40 parts of isophorone diisocyanate, 0.4-0.8 part of dibutyltin dilaurate, 3-6 parts of dimethylolpropionic acid, 15-20 parts of composite flame retardant, 2-4 parts of 1, 3-butanediol, 2-4 parts of 1, 3-butanediol, 2-4 parts of 1, 3-butanediol, 2-4 parts of 1, 3-butanediol, 2-4 parts of 1, 3-butanediol, 2 and 1 to 3 parts of 1, 4-butanediol and 1 to 3 parts of perfluorooctyltriethoxysilane. The preparation method comprises the following steps: 1) preparing castor oil-based polyester polyol through hydroxylation reaction and polycondensation; 2) taking graphene oxide as a core, grafting phosphorus and nitrogen flame-retardant groups and carrying out silane-titanate synergistic modification to prepare a composite flame retardant; 3, polyhydric alcohol and isocyanate are pre-polymerized, then the chain extender, the composite flame retardant and the auxiliaries are sequentially added, and curing molding.The material has low smoke and excellent flame retardance, mechanical property and hydrophobic stability through the synergistic effect of graphene and a phosphorus-nitrogen flame-retardant system, and is suitable for the field of flame-retardant high polymer materials for buildings, electronic packaging and the like.

The invention relates to the technical field of electronic packaging adhesives, in particular to a coating film for COB (Chip On Board) surface treatment and a preparation process of the coating film. According to the invention, titanium-containing polysiloxane is prepared, and titanium atoms are connected into the structure of polysiloxane, so that the high temperature resistance and mechanical properties of the COB packaging adhesive are improved, and the mechanical properties, high temperature resistance and aging resistance of a coating film are further improved; according to the present invention, the organosilicon elastomer microspheres and the oyster shell powder-polymethylhydrosiloxane graft are subjected to mutual crosslinking so as to obtain the organosilicon elastomer composite material, such that the thermal expansion coefficient and the mechanical property of the COB packaging adhesive can be adjusted by using the oyster shell powder component so as to further enhance the mechanical property and the high temperature resistance of the coating film, and reduce the warping rate of the coating film; and the curing forming speed of the covering film is increased, the curing time is shortened, and the production efficiency is improved.

The present invention relates to an intrinsically high thermal conductivity-low dielectric polyimide film, its preparation method, and applications. The polyimide is composed of polyimide A and polyimide B through blending or grafting. The polyimide film of the present invention has intrinsically high thermal conductivity, low dielectric constant and loss, and excellent heat resistance and mechanical properties. It has broad application prospects in integrated circuits, electronic packaging, and other fields.

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 relates to the technical field of metal-based composite materials, and discloses a preparation method of a silicon carbide reinforced aluminum-based composite material for electronic packaging, the method that pre-oxidation is conducted on the surfaces of silicon carbide particles first and then vacuum micro-evaporation titanium plating is conducted is adopted, the wettability with an Al matrix is obviously improved, generation of an interface reaction brittle product Al4C3 is inhibited, and the performance of the silicon carbide reinforced aluminum-based composite material is improved. Defects such as gaps in the composite material are reduced, and the mechanical property of the composite material is improved; the silicon carbide reinforced aluminum-based composite material is prepared by adopting a non-pressure infiltration method, so that the production time is obviously shortened, infiltration can be successful by taking a small amount of time, and the process is stable; the interface phase TiC / Ti5Si3-Al coating not only improves the electrical conductivity and thermal conductivity of the silicon carbide powder, but also enhances the adhesive force of the silicon carbide powder and an aluminum base; al2O3 is gradually adsorbed and deposited on the surface of the material by adopting a micro-arc oxidation process, so that the corrosion resistance of the aluminum silicon carbide composite material is enhanced, and the requirements of a contemporary packaging material on high heat dissipation and corrosion resistance can be met.

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 provides an aluminum-based composite material reinforced by nickel-coated silicon carbide through a magnetron sputtering dry method and a preparation process of the aluminum-based composite material, and relates to the technical field of metal-based composite materials and advanced electronic packaging thermal management materials. Comprising the following steps that S1, silicon carbide particles coated with nickel through a magnetron sputtering dry method and aluminum powder are put into a mold to be subjected to compression molding, and an initial blank is obtained; and S2, the initial blank prepared in the step S1 is placed in a re-pressing sintering furnace under the inert gas protection condition, continuous re-pressing is conducted under the temperature condition ranging from the temperature lower than the aluminum melting point by 50 DEG C to the temperature higher than the aluminum melting point by 200 DEG C, and the nickel-coated silicon carbide reinforced aluminum-based composite material obtained through the magnetron sputtering dry method is obtained. The aluminum-based composite material reinforced by magnetron sputtering dry nickel-coated silicon carbide disclosed by the invention is excellent in heat-conducting property and mechanical property and long in service life.

The invention relates to the technical field of solder paste, in particular to halogen-free soldering flux for solder paste and a preparation method of the halogen-free soldering flux. The halogen-free soldering flux for the solder paste comprises the following raw materials in parts by mass: 20-40 parts of hydrogenated rosin, 1-5 parts of maleic anhydride, 0.1-0.4 part of p-toluenesulfonic acid, 1-5 parts of activated mesoporous silica, 10-20 parts of a composite organic acid active agent, 5-10 parts of a thixotropic agent, 1-3 parts of a tackifier, 1-2 parts of a pH regulator, 1-2 parts of a surfactant, 1-2 parts of a chelating agent, 1-2 parts of an antioxidant and 50-80 parts of an organic solvent. Through the innovative component design and the preparation process, the technical contradiction existing in the field of halogen-free scaling powder for a long time is effectively solved, and an ideal material solution is provided for high-reliability electronic packaging.

The invention discloses a high-thermal-conductivity PI / ceramic composite insulation packaging sheet and a preparation method thereof, and relates to the technical field of electronic packaging. The high-thermal-conductivity PI / ceramic composite insulation packaging sheet is obtained by mixing a modified polyimide solution and modified ceramic particles according to the mass ratio of (9-13): 1 and then performing high-temperature curing. The modified polyimide solution is obtained by mixing a dianhydride monomer and a diamine monomer in a molar ratio of 1: 1, and 2-methyl-2-acrylic acid-2, 3-dihydroxy propyl ester accounting for 5-10% of the total molar weight, and adding a catalyst for catalysis; the modified ceramic particles are obtained by adding hydroxymethyl acrylamide into a ceramic suspension, mixing, filtering, washing and drying. The packaging sheet prepared by the invention has high thermal conductivity, keeps stable at a relatively high temperature, is not easy to thermally deform, and has relatively high stability.

The invention belongs to the technical field of electronic packaging defect detection, and particularly discloses a semiconductor packaging welding spot defect detection system and a detection method thereof.The system comprises an infrared excitation module and an ultrasonic signal processing module; a to-be-detected packaging sample wafer is arranged on a laser emergent light path of the infrared excitation module during detection, and is positioned in a detection focus area of the ultrasonic signal processing module; the infrared excitation module scans a to-be-tested packaging sample wafer by using the output infrared laser so as to thermally excite the internal structure of the to-be-tested packaging sample wafer and primarily generate an ultrasonic signal; when the infrared excitation module scans, the ultrasonic signal processing module synchronously detects a first ultrasonic signal generated by each scanning position point on the to-be-detected packaging sample wafer, and determines a welding spot defect detection result of the to-be-detected packaging sample wafer based on the first ultrasonic signal of each scanning position point. According to the invention, the precision and sensitivity of semiconductor packaging welding spot defect detection can be effectively improved.