18 results about "Electrochemical migration" patented technology

This invention relates to the manufacture of metal powders and discloses a controllable preparation method for semiconductor-grade ultrafine spherical aluminum powder, comprising: preparing a composite molten salt composed of a matrix salt and an interface pinning agent calcium fluoride and heating it to a dispersion temperature to form a homogeneous melt; shearing and dispersing liquid aluminum in the melt; performing temperature-controlled dissolution, controlling the cooling rate to allow calcium fluoride to precipitate in situ and adsorb before the aluminum droplets solidify, forming a physical pinning shell layer; and restricting solidification and removing the salt medium. This invention utilizes the temperature-dependent solubility characteristics to construct a microscopic physical barrier before the droplets solidify, effectively blocking droplet aggregation through steric hindrance, achieving high sphericity and extremely narrow particle size distribution of the aluminum powder; simultaneously, it utilizes calcium fluoride microcrystals to induce the formation of a dense fluorinated aluminum oxide composite passivation layer, improving the powder's resistance to electrochemical migration and insulation reliability.

An electrochemical migration failure prediction analysis method based on dendritic crystal growth evolution comprises the following steps: carrying out an electrochemical migration experiment on a prepared test sample on a self-established electrochemical migration experiment platform, and monitoring the test sample in the electrochemical migration experiment through a digital three-dimensional video microscope. The formation condition of the dendritic crystal in the electrode spacing and the microstructure morphology change image are obtained, and a visual basis is provided for determining the growth position and rule of the dendritic crystal; matlab software is combined to carry out two-dimensional gray level conversion, contrast enhancement and noise reduction processing on a microstructure morphology change image on the surface of a test sample, and dendritic crystal surface area statistics is carried out on the processed dendritic crystal growth two-dimensional gray level image, so that dendritic crystal generation, evolution distribution characteristics and morphology characteristics in the electrochemical migration process are accurately reflected; compared with an existing electrochemical migration failure prediction analysis method, the method has better dynamic monitoring capacity, high real-time performance and high accuracy.

The invention relates to preparation and application of Ag-In composite soldering paste for inhibiting electrochemical migration of sintered silver, and belongs to the field of packaging and interconnection of wide bandgap semiconductor devices. The Ag-In composite soldering paste is formed by mixing micro-nano silver particles, nano indium particles, an alcohol organic solvent and a silane coupling agent, the mass percent of the silver soldering paste is 85%-95%, and the mass percent of the indium paste is 5%-15%. The Ag-In composite soldering paste can effectively prolong the electrochemical migration life to more than 1000 hours under the harsh conditions of high temperature (400 DEG C) and high external voltage (400V), and compared with pure silver soldering paste, the Ag-In composite soldering paste has the advantages that the shear strength attenuation is within 10%, and the mechanical and electromigration resistance reliability of a wide bandgap semiconductor device can be remarkably improved.

The invention relates to an electrochemical migration resistant low-temperature sintered silver paste and a preparation method thereof, and relates to the technical field of chemical paste, the low-temperature sintered silver paste comprises 60-90 parts by weight of compound silver powder, 10-30 parts by weight of an organic carrier, 0.1-3 parts by weight of a functional additive and 0.05-0.3 part by weight of SiO2 nanoparticles; wherein the compound silver powder comprises modified silver powder and compound silver powder; the modified silver powder is obtained by adding a surface load into the composite silver powder; in the modified silver powder, the mass part of the surface load is 0.2-0.8 part by weight; in the compound silver powder, the mass part of the modified silver powder is 20-100 parts by weight, so that a double protection mechanism of physical barrier and chemical passivation is constructed in the obtained silver paste, and the electrochemical migration resistance and the long-term use reliability of the silver paste are expected to be remarkably improved while the excellent electric conduction and heat conduction properties of the silver paste are maintained.

The invention relates to manufacturing of metal powder, and discloses a controllable preparation method of semiconductor-grade superfine spherical aluminum powder, which comprises the following steps: preparing composite molten salt consisting of matrix salt and interface pinning agent calcium fluoride, and heating to a dispersion temperature to form homogeneous melt; shearing and dispersing molten aluminum into the melt; temperature-controlled solventing-out is executed, and the cooling rate is controlled, so that calcium fluoride is separated out in situ and adsorbed to form a physical pinning shell layer before the molten aluminum drops are solidified; according to the method, a microcosmic physical barrier is constructed before liquid drops are solidified by utilizing the solubility temperature change characteristic, liquid drop coalescence is effectively blocked through the steric hindrance effect, and the high sphericity degree and extremely narrow particle size distribution of the aluminum powder are achieved; and meanwhile, calcium fluoride microcrystals are used for inducing to generate a compact aluminum fluoride oxide composite passivation layer, so that the electrochemical migration resistance and the insulation reliability of the powder are improved.

This disclosure relates to a low-temperature sintered silver paste with resistance to electrochemical migration and its preparation method, belonging to the field of chemical paste technology. The low-temperature sintered silver paste comprises: 60-90 parts by weight of compounded silver powder, 10-30 parts by weight of organic carrier, 0.1-3 parts by weight of functional additives, and 0.05-0.3 parts by weight of hydrophobic SiO2 nanoparticles; wherein, the compounded silver powder includes modified silver powder and composite silver powder; the modified silver powder is obtained by adding surface loading to the composite silver powder; in the modified silver powder, the surface loading has a mass part of 0.2-0.8 parts by weight; in the compounded silver powder, the modified silver powder has a mass part of 20-100 parts by weight. This achieves the construction of a dual protection mechanism of physical barrier and chemical passivation in the obtained silver paste, which is expected to significantly improve its resistance to electrochemical migration and long-term reliability while maintaining the excellent electrical and thermal conductivity of the silver paste.

This invention relates to the field of building electrical fire early warning technology, specifically disclosing a method and system for early identification of building electrical hazards based on weak signal monitoring. The method includes: using geomagnetic induced current as a passive excitation source to capture the structural phonon flow excited in the micro-region of the hazard, collecting near-field evanescent electromagnetic waves leaking from the insulation surface, and establishing a phonon-evanescent wave coupling characteristic flow; inverting the electrochemical migration concentration field and space charge accumulation density field based on the phonon group velocity dispersion and evanescent wave polarization characteristics, constructing a time-series causal graph model using the transfer entropy algorithm, and calculating the causal structure deviation from the dynamic causal baseline; matching the deviation with multidimensional hazard criteria to distinguish between electrochemical migration-dominated and space charge breakdown-dominated hazards, and outputting accurate early warnings. This invention, by revealing the causal coupling mechanism between electrochemical migration and space charge accumulation, achieves non-invasive ultra-early identification and etiology-level diagnosis of building electrical hazards in their nascent stage.

The invention discloses nano copper powder, electrode copper paste, a buzzer and a preparation method of the buzzer, and relates to the technical field of metal material and electronic component manufacturing. The surface of a copper powder matrix is coated with an organic-inorganic composite layer, organic-inorganic combination is utilized, inorganic components react with the surface of the copper powder to generate a layer of compact composite passivation film, the protection performance is excellent, meanwhile, organic components form covalent bonds and coordinate bonds through complex reaction and chemical adsorption, the covalent bonds and the coordinate bonds are alternated to form a chain polymer, and the covalent bonds and the coordinate bonds are separated from the covalent bonds and the coordinate bonds. A plurality of layers of protection films in parallel orientation are formed on the surface of copper, so that the surface of the copper is not subjected to oxidation-reduction reaction, the anti-oxidation effect is achieved, and the conductivity of the copper is guaranteed. In addition, the organic-inorganic composite layer can efficiently inhibit copper oxidation and electrochemical migration even at a high temperature, and the stability of the organic-inorganic composite layer is obviously superior to that of silver paste in a humid and hot environment.

The invention relates to the technical field of solder materials for electronic packaging, and discloses an electrochemical migration resistant tin-based solder alloy and a preparation method thereof.The tin-based solder alloy is based on Sn, and Ag, Cu, Zn, neodymium triacetylacetonate, a TiC-SiC mixture, a graphene / carbon nanotube / Ti < 3 > C < 2 > T < x > MXene composite system and other components are added. The preparation method comprises the steps of raw material pretreatment, vacuum melting, in-situ reaction, two-stage cooling and gradient aging. The migration-resistant failure time of the alloy is greater than or equal to 500s, the tensile strength is greater than or equal to 350MPa, the melting point is 215-225 DEG C, and the alloy can stably work in a high-humidity environment at the temperature of-50-150 DEG C, is adaptive to high-end electronic packaging of AI chips, data center servers and the like, and has large-scale production potential.

The invention relates to a method for processing a bevel edge of a golden finger area of a printed circuit board, which sequentially comprises the following steps of: A, resistance welding and windowing: windowing a golden finger body and an adjacent lead area in a resistance welding process, and exposing a copper surface of the area; b, conducting wire area etching: completely removing the copper layer of the adjacent conducting wire area on the outer side of the golden finger body through a graphical etching process; and C, bevel edge forming: performing bevel edge cutting along the copper-free isolation strip formed by etching in the lead area, wherein the cutting boundary ends at the copper-free isolation strip and is far away from the golden finger body. The metal exposure risk during bevel edge cutting is thoroughly eliminated through the copper-free isolation strip, and an electrochemical migration path is blocked; no metal contact exists in the whole cutting process, conductive chippings are completely eradicated, and the hidden danger of short circuit in a high-frequency plugging scene is solved; the isolation belt design is compatible with conventional equipment precision, and the process error-tolerant rate and reliability are improved.

The utility model relates to the technical field of ionic rare earth mining, in particular to a column leaching test device for simulating ionic rare earth electric mining. Comprising a direct-current stabilized power supply, an ore body leaching soil column device, a peristaltic pump, an electrolyte storage device and a leachate collection device, the ore body leaching soil column device comprises an upper water system microfiltration membrane, an upper quartz sand cushion layer, an upper combined electrode, mine area humus layer soil, mine area fully-weathered layer soil, mine area semi-weathered layer soil, a lower combined electrode, a lower quartz sand cushion layer and a lower water system microfiltration membrane from top to bottom. Compared with the prior art, the device has the advantages of simplicity in manufacturing, low cost, high experimental flexibility and the like, different experimental conditions can be flexibly adjusted, and the exploration time of various parameters of the ionic rare earth electric mining technology is remarkably shortened; the release migration mechanism of various ions under different voltage conditions is disclosed, the electrochemical migration mechanism of heavy metal ions is clarified, and powerful theoretical support is provided for green mining of mines and ecological environment protection.

An electronic component that can suppress occurrence of problems such as electrochemical migration. An electronic component includes an insulator where a plurality of insulating substrates, each being provided with a side electrode and an inner electrode, are placed upon each other; and outer electrodes that are electrically connected to the side electrodes and that are provided at side surfaces of the insulator. The plurality of insulating substrates are each further provided with dummy electrodes that are disposed on a corresponding one of two sides of the side electrode with an insulating portion being interposed therebetween when viewed from a placement direction. The outer electrodes are electrically connected to the dummy electrodes at the side surfaces of the insulator.

The invention belongs to the technical field of electronic packaging materials, and relates to an anti-migration conductive silver adhesive and a preparation method thereof, and the anti-migration conductive silver adhesive comprises the following components by weight: 70-90% of silver powder; 6%-15% of a resin matrix; 1.5%-5% of a curing agent; 2%-15% of a diluent; and 0.5%-3% of a sulfur-containing silane coupling agent. The sulfur-containing silane coupling agent forms a strong chemical bond with silver through sulfydryl of the sulfur-containing silane coupling agent, and a hydrophobic membrane is formed through hydrolytic condensation, so that a dual inhibition mechanism on silver migration is realized; the performance is excellent; the electrochemical migration failure life in a high-temperature and high-humidity environment is prolonged; the sulfur-containing silane coupling agent is added on the basis of an existing conductive silver adhesive formula, complex pretreatment or synthesis steps are not needed, the conductive silver adhesive is suitable for industrial large-scale production, precious metal such as palladium is not introduced, and the cost advantage is obvious; and the compatibility is good.

The invention relates to the technical field of tin-based soldering paste, and discloses tin-based soldering paste resistant to electrochemical migration and a preparation method thereof.The tin-based soldering paste resistant to electrochemical migration comprises 85-92 parts of soldering alloy powder and 8-15 parts of scaling powder. The tin-based soldering paste has excellent electrochemical migration resistance, good welding manufacturability and mechanical reliability, metal dendritic crystal growth in severe environments such as damp and hot environments and high-voltage environments can be effectively inhibited, the short-circuit risk of welding spots is reduced, the service life of electronic equipment is prolonged, and the tin-based soldering paste meets the welding requirements of high-density and miniaturized electronic equipment.

The invention provides a silver micro bump interconnection structure and method based on liquid phase diffusion welding. The silver micro bump interconnection structure comprises a first silicon wafer; the first silicon wafer is provided with first silver micro-convex points which are distributed in an area array, the surfaces of the first silver micro-convex points are covered with low-melting-point eutectic films, and the thickness of the low-melting-point eutectic films is larger than or equal to 1 micron; and a second silicon wafer; the second silicon wafer is provided with second silver micro convex points which are distributed in an area array mode, the surfaces of the second silver micro convex points are smooth, and the second silver micro convex points are connected with the low-melting-point eutectic film through liquid phase diffusion welding. According to the silver micro-bump interconnection structure provided by the invention, the electrochemical migration resistance and the oxidation resistance of the silver bumps after the silver micro-bumps are welded can be improved. Solid-state interconnection of interface all-metal is achieved through liquid phase diffusion, low-temperature and low-stress welding is achieved, meanwhile, the interconnection reliability, the electrochemical migration resistance and the oxidation resistance of the silver micro-convex points are remarkably improved, and the method is suitable for the micro-interconnection application requirement in high-performance electronic packaging.

The invention discloses a chip unmarked detection method and system, and particularly relates to the technical field of nondestructive detection of chip packaging internal defects. The method is used for solving the technical problem that effective penetration, high-resolution imaging and material component specific recognition of electrochemical migration defects in a biocompatible polymer packaging material are difficult to realize in the prior art. The method comprises the following steps: acquiring a terahertz image formed by a to-be-detected chip under the irradiation of terahertz waves to identify a to-be-analyzed area in a packaging material, acquiring Raman scattering spectrum data of the to-be-analyzed area, and respectively extracting first spectrum data and second spectrum data from the Raman scattering spectrum data; and judging the metallic substance by comparing the first spectral data with the metal characteristic spectral data, judging the local chemical denaturation by comparing the second spectral data with the denaturation characteristic spectral data of the packaging material, and finally judging that the electrochemical migration defect exists in the region when the metallic substance and the local chemical denaturation exist in the region to be analyzed at the same time.

The invention provides a high-brightness flip LED chip and a preparation method thereof, the flip LED chip comprises a substrate, a semiconductor layer, a metal reflection layer and a first passivation layer, the semiconductor layer is arranged on one side of the substrate, and the semiconductor layer comprises an N-type semiconductor layer, an active layer and a P-type semiconductor layer which are stacked in sequence; the metal reflecting layer is arranged on one side, deviating from the substrate, of the semiconductor layer; the first passivation layer is arranged on the side, away from the substrate, of the metal reflection layer; wherein the side wall of the metal reflecting layer is in contact with the first passivation layer, areas limited by orthographic projection of the edge of the first passivation layer on the substrate comprise a first area, a second area and a third area, the thicknesses of the first passivation layer in the first area, the second area and the third area are sequentially reduced, the thickness of the first passivation layer in the third area is 0, and the thickness of the second passivation layer in the third area is 0. According to the flip LED chip, the electrochemical migration problem of the metal reflecting layer can be improved, the reflecting area of the metal reflecting layer is enlarged, and the brightness of the flip LED chip is improved.

The invention provides a semiconductor device preparation method for improving nano-silver sintering reliability. The method comprises the following steps: S1, preparing a target semiconductor chip 2; s2, providing a bearing frame 1, and packaging the target semiconductor chip 2 on the bearing frame 1 through nano-silver soldering paste 3 to obtain a first semi-finished product; s3, performing nano-silver sintering on the target semi-finished screen to obtain a second semi-finished product; and S4, target ions are added to the surface of the second semi-finished product, so that a reaction transition layer 4 and a compact protection layer 5 are sequentially formed on the surface of the nano-silver soldering paste 3, and the target semiconductor device is obtained.The silver ion release can be effectively blocked, and electrochemical migration is slowed down.