65 results about "Composite solder" patented technology

The invention relates to the technical field of circuit substrate manufacturing, and particularly discloses a preparation method of a composite solder sheet and an AMB ceramic copper-clad plate. The composite solder sheet is composed of an active metal foil and a copper-containing layer modified on the surface of the active metal foil, and the preparation method of the copper-clad plate comprises the following steps: after the surface of the active metal foil is pretreated, the copper-containing layer is deposited to prepare the composite solder sheet, and the composite solder sheet is placed between a copper substrate and a ceramic sheet to be pressed and assembled. And performing vacuum brazing on the assembly to complete the preparation of the ceramic copper-clad plate. A composite solder sheet containing active metal is adopted, high-temperature element diffusion during vacuum brazing is utilized at the diffusion temperature to achieve alloying of a composite solder layer, and then heat preservation is conducted at the brazing temperature to achieve uniform melting of solder and wetting metallurgical reaction between the solder and copper and between the solder and a ceramic substrate. By means of the preparation method, low-cost and high-reliability preparation of the AMB ceramic copper-clad plate can be achieved, and the prepared AMB ceramic copper-clad plate also has high peel strength and lower weld porosity.

The invention discloses an intelligent assembly method of a precise connector, which comprises the following steps of: adding phase change particles with different melting points into tin-silver-copper-based solder according to the difference of functional areas of welding spots in the connector, generating an area formula index, and obtaining composite solder with partition identification; according to the area formula index, the composite welding flux is deposited to preset welding spot positions according to the functional areas, and particle distribution information is recorded; performing reflow soldering on different functional areas by adopting corresponding temperature curves according to the melting point parameters of the phase change particles, and recording the temperature history of each area; applying pulse thermal excitation to the packaged connector, and collecting a surface temperature change curve of each welding spot to obtain thermal response data; and performing correlation comparison on the thermal response data and process historical data, identifying the welding spot defect type according to curve deviation characteristics, and generating process adjustment parameters. According to the scheme, after the connector is completely packaged, rapid nondestructive detection of internal tiny welding spots can be realized, hidden defects can be effectively identified, and intelligent optimization and adjustment of process parameters can be realized.

The invention discloses an Ag-Cu-Ti-Zr-B active composite brazing filler metal and a preparation method of the Ag-Cu-Ti-Zr-B active composite brazing filler metal. The active composite brazing filler metal is composed of, by mass, 5%-8% of Ti, 2%-5% of Zr, 0.1%-2% of B and the balance Ag-28Cu eutectic components. The Ag-Cu-Ti-Zr-B active composite brazing filler metal prepared through the method has the advantages that the wettability is improved, the interface bonding strength is enhanced, the joint structure is refined, the brazing temperature is reduced, the fluidity and permeability are improved, and the heat resistance and corrosion resistance are improved. Due to the characteristics, the brazing filler metal becomes excellent brazing filler metal in ceramic metal brazing, and is particularly suitable for connection of high-performance ceramic and metal.

The invention discloses AgCuSnTi-based composite brazing filler metal. Raw materials of the AgCuSnTi-based composite brazing filler metal comprise alloy powder and yttrium tungstate powder. The volume of the yttrium tungstate powder accounts for 0.5-5% of the total volume of the powder; and the alloy powder comprises the following raw materials in percentage by weight: 8.5 to 9.5 percent of Sn, 1.2 to 1.5 percent of TiH2 and 89.1 to 90.3 percent of AgCu eutectic powder. The invention further discloses a preparation method of the AgCuSnTi-based composite brazing filler metal. The invention further discloses the AgCuSnTi based composite brazing filler metal soldering paste. The invention further discloses the application of the AgCuSnTi-based composite brazing filler metal and the application of the AgCuSnTi-based composite brazing filler metal soldering paste in welding of diamond and copper. The invention further discloses a diamond and copper welding method. According to the brazing filler metal and the soldering paste, the residual stress of a diamond and copper welding joint can be greatly relieved, and the service stability of a welding assembly is improved.

The invention belongs to the technical field of brazing materials, and discloses high-entropy composite brazing filler metal and a preparation method and application thereof. The high-entropy composite brazing filler metal comprises a nickel-based brazing filler metal matrix and high-entropy alloy powder, and the high-entropy alloy powder comprises, by atomic percent, 15%-25% of Co, 15%-25% of Cr, 15%-25% of Fe and 25%-45% of Ni. According to the high-entropy composite brazing filler metal, the low melting temperature is kept, the high-entropy alloy particles can adjust joint residual stress caused by the large difference of thermal expansion coefficients of dissimilar materials, the interface regulation and control effect is achieved, generation and distribution of joint brittle phases are affected, a special core-shell structure is formed around the high-entropy particles, and therefore the high-entropy composite brazing filler metal can be obtained. A continuous brittle phase formed by a joint can be broken, crack propagation is prevented, the mechanical property of the joint is remarkably improved, the brazing filler metal preparation method is simple and easy to implement, and the high-entropy composite brazing filler metal adopts an instantaneous liquid diffusion brazing mode, so that weld joint structure components are homogenized.

The utility model particularly relates to a processing device for a re-welding contact strip, which comprises a feeding device, a receiving device and a control system, a conveying pipeline is arranged between the feeding device and the receiving device, the feeding device conveys the strip to an inlet of the conveying pipeline, and the receiving device conveys the strip to the inlet of the conveying pipeline. The discharging device comprises a first discharging device for conveying a contact strip and a second discharging device for conveying a compound solder contact strip, the conveying speed of the first discharging device is the same as that of the second discharging device, and the interior of the conveying pipeline is sealed and is provided with a protective atmosphere; the conveying pipeline is sequentially provided with a composite solder heating device for heating the protective atmosphere and a cooling device for cooling the protective atmosphere in the direction from the inlet to the outlet. According to the processing device, the product consistency is good, air holes are not prone to being generated in the product, the strength and toughness of the finished product are high, the requirement for automatic production of the contact assembly is met, the production efficiency is high, manufacturing is easy, and the length can reach 100-300 m.

The invention relates to the technical field of dissimilar material connection, in particular to a lead-free composite brazing filler metal and method for low-temperature connection of large-size ceramic and metal, the composite brazing filler metal is obtained by mixing copper powder and tin-bismuth welding powder according to the mass ratio of 1: 75-100, tabletting and standing; wherein the tin content in the tin-bismuth welding powder is 42%, and the bismuth content in the tin-bismuth welding powder is 58%. According to the Cu-SnBi composite solder developed by the invention, the brittleness of the SnBi solder is effectively avoided, and the Cu-SnBi composite solder is particularly suitable for large-size (mainly aiming at electronic packaging welding spots at present and relatively small in size) brazing, can realize successful welding at the temperature of 200 DEG C or below without brittle cracking, and is excellent in comprehensive mechanical property.

The invention discloses a preparation method and application of a low-temperature photovoltaic welding strip, and belongs to the technical field of energy conservation and environmental protection. According to the technical scheme, the method comprises the steps that a metal precursor is dissolved in an alcoholic solution, and a nano reinforced phase is prepared through regulation and control of a surfactant, ultrasonic treatment and aging calcination; the composite solder is prepared through argon smelting according to 1-6 parts of Sn, Bi, Ag, Ni, Cu, Ge, the modified glass powder and the nano reinforced phase; 99.95% electrolytic copper is subjected to vacuum melting and cold rolling to form a copper strip; the surface roughness is controlled through alkali washing degreasing and acid washing micro-etching; immersing the preheated copper strip into a molten pool for plating; and carrying out heat preservation and rosin protection treatment. According to the method, low-temperature welding at the temperature of 150-220 DEG C is achieved, an Ag-Sn intermetallic compound layer is formed after welding, the pull-off strength retention rate of a welding spot is larger than or equal to 80% after 200 times of thermal cycles, and the method is suitable for interconnection of crystalline silicon photovoltaic battery pieces.

The invention belongs to the technical field of lead-free solder paste preparation, and discloses a lead-free composite solder paste with a high spreading rate and a preparation method. The lead-free composite soldering paste comprises soldering powder and soldering flux. The soldering flux is prepared from modified rosin, an activating agent, a surface active agent, a thixotropic agent, thermosetting resin, an antioxidant, a corrosion inhibitor and an organic solvent. The activating agent comprises hydroxy acrylic resin, terephthalic acid and ethylene bis stearamide. The prepared lead-free composite soldering paste is good in wettability, good in printability, low in corrosivity and less in residue, can effectively inhibit the occurrence of undesirable welding phenomena such as tin beads, dewetting and collapse, greatly reduces the reject ratio of printing, and improves the reliability of welding; the preparation method of the lead-free composite soldering paste is simple and easy to operate, raw materials are easy to obtain, and the lead-free composite soldering paste is suitable for industrial popularization.

The invention provides an electronic speed regulator capacitor installation structure and an installation method thereof. The electronic speed regulator capacitor installation structure comprises a main circuit board, a transition circuit board and a capacitor. The main circuit board is provided with a first through hole, and a reinforced bonding pad is formed at the first through hole; a second through hole is formed in the transition circuit board, a golden finger type bonding pad is arranged at the lower end of the transition circuit board, the golden finger type bonding pad is electrically connected with the second through hole, and the golden finger type bonding pad of the transition circuit board penetrates through the first through hole and forms a composite welding spot through welding; a plurality of capacitors are arranged along the length direction of the transition circuit board. Pins of the capacitors are vertically inserted into the second through holes and form composite welding spots through welding. The capacitor mounting structure of the electronic speed regulator is easy to produce, high in tensile strength and high in mechanical and electrical performance reliability.

The invention relates to active composite brazing filler metal suitable for welding ceramics and copper materials and a preparation method of the active composite brazing filler metal. The active composite brazing filler metal is composed of a plastic matrix layer and an active coating. The plastic matrix layer is a metal foil containing at least one of Ag, Cu and Ni; the active coating is an active metal layer arranged on the plastic matrix layer, and active metal is selected from at least one of Ti, Zr, Cr, Hf, V and Nb. The active coating is divided into two layers, the upper layer is a TiH2 active metal layer, and the lower layer is a TiH2 active metal layer. The metal foil is an AgCu28 foil, and the active coating is a TiH2 active brazing filler metal. The preparation method of the active composite brazing filler metal comprises the steps that S1, the metal foil and the active composite brazing filler metal paste are prepared; s2, the metal foil is coated with the active composite brazing filler metal paste; and S3, baking is conducted in the environment of 80-150 DEG C, and the active composite brazing filler metal is formed. The method is simple, reasonable, high in efficiency, low in cost and high in reliability.

The invention discloses a composite solder ball, a preparation method and a stacked packaging structure, and the composite solder ball comprises a composite inner core which is composed of a continuous phase matrix and a strengthening phase, the strengthening phase accounts for 15-30% of the total volume of the inner core, the compression modulus of the composite inner core is larger than or equal to 3 GPa, and the thermal expansion coefficient of the composite inner core is smaller than or equal to 55 ppm / DEG C; the polymer core is coated with the metal transition layer; and the tin-silver alloy outer layer covers the metal transition layer. The composite inner core is composed of a continuous phase polymer matrix and a strengthening phase fiber network, high-temperature compression resistance and low thermal expansion characteristics are achieved through a specific volume ratio and a specific mass ratio, the solid-state rigidity characteristic is kept in a welding high-temperature interval, mechanical loads are directly borne, the interlayer height collapse risk is thoroughly eliminated, and the welding quality is improved. The metal transition layer forms a mechanical interlocking combination interface with the inner core, and the tin-silver alloy outer layer provides weldability and an electric connection function, so that double-function technology fusion that the composite solder ball can play a supporting role and also can play a welding role is realized.

The application discloses a MAX phase reinforced three-dimensional network tin-based lead-free solder and a preparation method thereof, and belongs to the technical field of lead-free solder. The MAX phase reinforced three-dimensional network tin-based lead-free solder is characterized in that the MAX phase reinforcing phase is distributed in the form of a three-dimensional continuous network skeleton at the grain boundary of a tin-based lead-free solder matrix; and the MAX phase reinforcing phase forms a continuous network penetrating through the whole tin-based lead-free solder matrix. The application also discloses an application of the MAX phase reinforced three-dimensional network tin-based lead-free solder in a high-temperature, high-load and high-frequency vibration scene. Through process innovation and performance optimization, the application aims to finally prepare a "high-strength, high-plasticity and high-temperature stability" tin-based three-dimensional network composite solder, solves the problem that a traditional tin-based single-component lead-free solder is prone to deformation and cracking due to thermal stress and mechanical load, improves the reliability of electronic packaging, and expands the application range of the tin-based lead-free solder in high-demand fields.

The production process of the photovoltaic V-shaped composite welding strip comprises the steps of prefabrication of an alloy copper strip, prefabrication of an alloy aluminum strip, prefabrication of alloy calcium powder and synthesis and mold pressing processes. The prefabricated alloy calcium powder, the alloy aluminum strip and the alloy copper strip are compounded and subjected to mould pressing through a synthesis mould pressing process, and the inclined grain V-shaped composite welding strip with inclined grains on the A surface is synthesized; the sloping grain V-shaped composite welding strip is subjected to surface cleaning, tin plating on the surface B and silver plating on the surface A to obtain the photovoltaic V-shaped composite welding strip. The photovoltaic V-shaped composite solder strip has the beneficial effects that the photovoltaic V-shaped composite solder strip manufactured by adopting the production process is low in cost, high in conductivity, low in failure rate, low in use and maintenance cost and long in service life; the cost of photovoltaic products can be reduced, application and popularization of the photovoltaic products are promoted, and immeasurable beneficial effects are brought to development of ecological energy and environmental protection.

The application discloses a preparation method of a high-reliability core-shell composite solder capable of low-temperature welding, and belongs to the technical field of welding materials of electronic components. The core-shell composite solder is made of Sn-based solder powder by means of rolling plating, and a series of Sn-Bi low-temperature alloy plating layers are plated on the surface of the solder powder. The core-shell composite solder powder is produced in batches by changing the type and size of the commonly used Sn-based solder in the core to plate a series of Sn-x Bi low-temperature solder alloy plating layers on the shell, so as to produce core-shell composite solder powders of different sizes and types and composite BGA solder balls. The composite solder powder is suitable for the preparation of solder paste capable of low-temperature reflow and high-temperature service, and the composite BGA solder ball can be directly used for solder balls capable of low-temperature reflow and high-temperature service, so that the types and usability of the composite solder at the present stage are greatly improved, and the welding reliability is improved. Compared with the alloy solder prepared by the traditional melting and casting method, the method has the advantages of simple process, low cost and easy operation.

The invention belongs to the technical field of semiconductor welding, and particularly relates to a high-reliability solder structure and a processing method and equipment thereof, the high-reliability solder structure comprises lead-free solder and a high-melting-point metal block, the lead-free solder is selected from one or more combinations of Sn-based solder and In-based solder, and the high-melting-point metal block is selected from one or more combinations of Sn-based solder and In-based solder. The high-melting-point metal block comprises pure metals of Cu, Ni, Ag and Zn and alloys thereof, and a protective layer of pure metals of Sn and In and alloys thereof can be arranged on the surface of the high-melting-point metal block; due to the fact that the height limiting block with the high melting point is arranged in the composite solder, control over the height is more accurate. After the welding flux is melted, the welding flux does not flow around under the action of surface tension.

The application is suitable for the technical field of solar cells, and provides a composite solder strip, a cell string, a cell module and a photovoltaic system. The composite solder strip comprises a first solder strip, an insulating strip and a second solder strip. The first solder strip, the insulating strip and the second solder strip extend along a first direction and are arranged in contact with each other along a second direction. The first solder strip comprises a first conductive piece and a plurality of first insulating pieces. The first insulating pieces are arranged on the first conductive piece and are distributed at intervals along the first direction. The first conductive piece is exposed between the adjacent two first insulating pieces to form a first cell connecting area. In this way, since the first solder strip and the second solder strip are integrated together through the insulating strip, the arrangement frequency of the solder strip can be reduced. Since the first solder strip comprises the first insulating pieces arranged at intervals, the first conductive piece is exposed between the adjacent two first insulating pieces to form the first cell connecting area, and thus the operation of insulating the solder strip from the non-corresponding grid lines one by one can be omitted. Therefore, the connection step of the solder strip and the cell piece can be simplified.

The present invention discloses a composite solder and a preparation method thereof, a packaging method, and a composite solder preparation method comprising the following steps: providing a basic solder, wherein the basic solder composition comprises 20% to 35% of metallic copper, 55% to 70% of metallic silver, and 10% to 15% of an auxiliary agent, wherein the mass ratio of metallic silver to metallic copper is (20 to 35): (50 to 70); placing metallic silver and metallic copper in an atmosphere containing a carbon source gas for plasma chemical vapor deposition treatment, preparing a prefabricated solder, and mixing the prefabricated solder and the auxiliary agent. Plasma enhanced chemical vapor deposition is used to in-situ grow nanographene on a basic solder containing metallic silver and metallic copper, the grown graphene is dispersedly distributed, and fine crystal strengthening can solve the problem that graphene is easy to agglomerate and hinder the flow of solder to cause hole formation, and the prepared composite solder can effectively improve the welding strength and realize the gradient transition of thermal expansion coefficient between ceramic-solder-metal.

A photovoltaic V-shaped composite solder strip comprises an alloy copper sheet layer, an alloy aluminum shell layer, an alloy calcium powder layer, soldering tin, a rectangular solder groove and a twill V-shaped groove, the alloy aluminum shell layer is a rectangular shell, and the alloy calcium powder layer is filled in the middle of the alloy aluminum shell layer; the periphery of the alloy aluminum shell layer is coated with an alloy copper sheet layer; four sides of the alloy copper sheet layer are provided with edges; a sloping grain V-shaped groove is formed in the surface A; the surface B is provided with a rectangular solder groove; the middle part of the surface B is provided with alloy copper sheet layers on two sides welded by soldering tin; the left side face and the right side face of the alloy copper sheet layer are smooth faces parallel to each other. The beneficial effects are that the device is low in cost, high in conductivity, low in fault rate, low in use and maintenance cost, and long in service life; the cost of photovoltaic products can be reduced, application and popularization of the photovoltaic products are promoted, and immeasurable beneficial effects are brought to development of ecological energy and environmental protection.

The utility model is suitable for the field of photovoltaic technology, and provides a composite welding strip, a back contact solar cell module and a photovoltaic system. The second conducting layer is arranged on the outer surface of the first conducting layer, the first conducting layer comprises aluminum, and the second conducting layer comprises copper; the connecting layer is arranged between the first conductive layer and the second conductive layer, and the yield strength of the composite welding strip is greater than or equal to 45MPa and less than or equal to 75MPa. According to the invention, the yield strength of the composite welding strip is controlled within a preset range, so that the problem that the composite welding strip is easy to warp to cause the warping of a battery piece can be avoided, and the battery piece yield strength is improved. Compared with a traditional copper solder strip, the cost is greatly reduced, and the production cost of a battery assembly is effectively reduced.

The invention relates to the technical field of semiconductor welding, in particular to a composite welding flux capable of being matched with different thermal expansion coefficients and a rolling technology. According to the composite welding flux, an iron-nickel alloy middle layer is used, and the thermal expansion coefficient of the composite welding flux can be adjusted within the range of 1.4-12 * 10 <-6 > K <-1 > according to the nickel content; the solder can meet the working requirement of a wide bandgap semiconductor material at the high temperature of 200-450 DEG C, and is obviously superior to a traditional tin-based solder and a high-lead solder. Due to the invar effect of the iron-nickel alloy middle layer, the thermal expansion coefficient of the iron-nickel alloy middle layer is highly matched with novel semiconductor materials such as SiC, SiN and GaN, welding joint cracks caused by the difference of the thermal expansion coefficients are effectively avoided, and therefore the problem that due to the fact that the thermal expansion coefficients of existing welding flux are not matched, the welding joint cracks is solved.

The invention relates to the technical field of battery manufacturing, in particular to a stress self-adaptive interconnection method and device for a thin film battery array based on a flexible PCB, and the method comprises the steps: processing and forming a micro-groove array on the surface of the PCB, and preparing a composite solder structure; collecting a real-time deformation field and a bonding pad position of the PCB, and generating a compensation mounting path of the thin film battery; the contact force between the thin film battery and the bonding pad is controlled to be smoothly increased; performing local thermal ultrasonic solid-phase bonding on the electrode on the thin film battery and the corresponding bonding point on the PCB; performing laser irradiation on the lower electrode of the battery and the PCB bonding pad to form a high-melting-point intermetallic compound; collecting three-dimensional shape geometric parameters of the welding spots, extracting efficiency distribution and defect characteristics of the battery, and dynamically adjusting process parameters of the upflow according to the efficiency distribution and defect characteristics; and calculating residual stress distribution, and dynamically adjusting pressure applied to different areas by a hot pressing roller in a subsequent packaging process. According to the invention, the large-scale and high-reliability manufacturing of the flexible PCB-based thin film solar wing can be effectively realized.

The invention relates to the technical field of ceramic substrates, and provides a high-heat-conductivity metal brazing copper-clad ceramic substrate and a preparation method thereof. The high-heat-conductivity metal brazing copper-clad ceramic substrate comprises a ceramic base body, composite solder and a copper sheet from bottom to top, and the composite solder is composed of, by weight, 20%-25% of Cu, 1%-5% of Ti, 1.4%-3.5% of active components and the balance Ag; the active components comprise Nb, Hf and Ta. According to the technical scheme, the problem that in the prior art, a metal brazing copper-clad ceramic substrate is low in heat conductivity is solved.

The application belongs to the technical field of solder processing, and discloses a composite solder piece and a preparation method thereof. The composite solder piece comprises a first low-melting-point solder layer, an Ag-based intermediate layer, a second low-melting-point solder layer and a solder coating which are stacked in sequence; wherein the first and second low-melting-point solder layers comprise a rare earth element-doped Ag-Cu-Sn alloy, and the Ag-based intermediate layer comprises a silver-based alloy doped with 0.5%-3% In and 0.1%-1.5% Ga elements. The design reduces the melting point of the intermediate layer by In / Ga doping to realize overall low-temperature brazing, and utilizes the rare earth element to refine grains and strengthen the interface, thereby synergistically improving the high-temperature strength and thermal fatigue resistance of the brazed joint. The outermost solder coating can improve wettability and provide oxidation resistance protection. The application significantly reduces the connection temperature while improving the high-temperature strength and wettability of the brazed joint, thereby ensuring excellent high-temperature reliability and process adaptability of the joint.

The application relates to the technical field of semiconductor packaging, in particular to a SnBi low-temperature hot-press bonding method and structure based on elastic microsphere enhancement, which comprises the following steps: S1, preparing SnBi-based composite solder paste containing metalized elastic microspheres, wherein the metalized elastic microspheres are uniformly distributed in the composite solder paste; S2, coating the composite solder paste to the pads of a substrate through a printing process; S3, aligning and placing a chip on the solder paste, and then preheating the chip through a heating head; S4, applying vertical pressure to the chip through the heating head and heating the chip to above the melting point of the composite solder paste, implementing hot-press bonding, so that the solder paste melts and the metalized elastic microspheres are compressed; and S5, forcibly cooling under the condition that the vertical pressure applied to the heating head is kept unchanged, and after the solder solidifies, the heating head removes the pressure, and the bonding is completed. Through the application, the problem that SnBi low-temperature solder joints are prone to brittle fracture and the problem that solder overflow leads to short circuit of the pads can be overcome.

The invention discloses a high-reliability medium-temperature composite solder and a preparation method thereof.The high-reliability medium-temperature composite solder comprises an alloy base material and a composite material, and the alloy base material comprises, by mass, 65-85 parts of Sn, 10-30 parts of In, 0.5-3 parts of Ag, 0.5-3 parts of Bi, 0.5-1.2 parts of Cu and 0.1-0.2 part of other metal elements; wherein the other metal elements comprise one of Sb, Ge, Co and Ni; the composite material comprises the following components in parts by mass: 0.1-1.0 part of nano copper powder used for inhibiting migration and remelting of an In-rich phase and forming a solid solution strengthening phase; and nano graphene powder. By means of the mode, according to the high-reliability medium-temperature composite solder and the preparation method thereof, the melting point of the whole composite solder is stabilized to be 175-200 DEG C by adjusting the In content, so that the high-reliability medium-temperature composite solder is accurately matched with a backflow technology at the temperature of 180-210 DEG C, and the thermal requirements of different electronic devices are met; and after the nano metal powder and the nano graphene powder are added, the In-rich phase remelting rate during secondary backflow is effectively reduced, the interface bonding strength is improved, and the reliability is remarkably improved.

The application discloses a kind of composite solder ball, preparation method and stacked package structure, comprising: composite core, by continuous phase matrix and strengthening phase are constituted, the strengthening phase accounts for 15%~30% of the total volume of core, the compression modulus of the composite core is ≥3GPa and thermal expansion coefficient is ≤55ppm / ℃;Metal transition layer, is coated in the polymer core;Tin silver alloy outer layer covering the metal transition layer.Composite core is constituted by continuous phase polymer matrix and strengthening phase fiber network, realizes high-temperature pressure resistance and low thermal expansion characteristics by specific volume ratio and mass ratio, maintains solid rigid characteristics in welding high temperature interval, directly bears mechanical load, completely eliminates the risk of interlayer height collapse, metal transition layer forms and the mechanical interlocking combination interface of core, tin silver alloy outer layer provides weldability and electrical connection function, realizes that composite solder ball can play the role of support and also can play the role of welding dual-functional technology fusion.

The application belongs to the technical field of tin paste, and particularly relates to a semiconductor packaging tin paste and a preparation method thereof for reducing welding cavities, which is composed of the following materials: composite solder powder: nano heterojunction composite tin powder, with a mass ratio of 85%-92%; flux: temperature-sensitive microcapsule flux, with a mass ratio of 7%-15%; trace functional additives: rheological agent, antioxidant and thixotropic agent, with a mass ratio of 0.15%-0.7%. The Mott-Schottky effect is used to enhance the interface electron transfer capacity, the organic small molecules of the flux residue can be actively catalyzed and decomposed in the welding heating stage, and the gas escape is reduced. Meanwhile, the lattice matching property of the heterojunction can inhibit the abnormal growth of the IMC layer, and the cavity problem caused by the uneven interface reaction of the traditional tin powder is solved.

This invention belongs to the technical field of lead-free solder powder for electronic soldering. The invention discloses a graphene-coated copper-tin composite solder powder and its preparation method. The core phase is a CuSn binary alloy powder, with a Cu content of 0.5~1.0 wt% and the balance being Sn; the D50 particle size is 15~45 μm, approximately spherical, and the loose packing density is 4.8~5.2 g / cm³. 3，壳相：少层还原氧化石墨烯，连续致密包覆层厚度 The graphene coating is 0.8~3.0nm, with a coating amount of 0.03~0.22wt% (based on the total mass of the composite solder powder). The interface is that the core phase and the shell phase are covalently bridged by silane coupling agent, with a coating integrity rate of ≥95%. The graphene does not agglomerate or fall off, and it plays a stable role in the reflow soldering process. The wettability, solder joint strength, and thermal fatigue performance of the solder powder reach or exceed those of SAC305 silver-containing solder powder. The process conditions are mild, highly controllable, and have good repeatability, making it suitable for large-scale industrial production. Moreover, the preparation process is environmentally friendly and generates no harmful waste.

The utility model relates to the technical field of solder temperature cycle test, and discloses a solder spot temperature cycle test device for Sn-Cu-Sn cladding composite solder, which comprises a test control box, a support plate is fixedly connected in the test control box, a placing plate is placed at the top end of the support plate, first heaters are mounted on two sides in the test control box, and a second heater is mounted in the test control box. A second heater is installed at the bottom end in the test control box, and a first temperature sensor and a second temperature sensor are installed in the test control box. According to the welding spot temperature cycle test device for the Sn-Cu-Sn cladding composite welding flux, the composite welding flux is placed through the placing plate, then the connecting rod is hooked on the placing plate, then the placing plate is placed on the supporting plate in the test control box, then the top plate is inserted into the mounting base, the top plate can be limited by rotating the limiting baffle, and the welding spot temperature cycle test device is convenient to operate. And during material taking, the limiting baffle is rotated away, and then the placing plate is moved out, so that the functions of flexible material placing and limiting are achieved, and the problem of inconvenience in material placing is solved.