35 results about "Electrochemical migration" patented technology

Silver electrode metallization in light emitting devices is subject to electrochemical migration in the presence of moisture and an electric field. Electrochemical migration of the silver metallization to the pn junction of the device results in an alternate shunt path across the junction, which degrades efficiency of the device. In accordance with a form of this invention, a migration barrier is provided for preventing migration of metal from at least one of the electrodes onto the surface of the semiconductor layer with which the electrode is in contact.

The invention discloses a preparation method of a modified carbon fiber microelectrode. The preparation method comprises the steps of surface activation of a carbon fiber, catalyst coating, carbon nanofiber vapor deposition, copper nano particle deposition and assembly. The invention further discloses the application of the modified carbon fiber microelectrode in detection of a nitric oxide concentration. Vapor deposition of the carbon nanofiber is performed on the surface of the carbon fiber; the specific surface area of the carbon fiber can be increased; the contact probability of the carbonfiber and ions is increased; the deposited copper nano particle can allow the carbon fiber to have an electroreduction effect; the reuse stability of the microelectrode can be improved, so that the carbon fiber microelectrode capable of detecting nitrate by a synergic electrochemical action of electrochemical migration and copper oxidoreduction is constructed; and compared with the existing carbon fiber microelectrode, the carbon fiber microelectrode has the advantages of high detection sensitivity, stable output, low energy consumption, high detection speed, simple operation, low preparationcost and the like and can detect nitric oxide in air in real time.

The invention discloses a nano silver copper alloy solid solution welding paste with sintering connection performance and a preparation method for the nano silver copper alloy solid solution welding paste and belongs to the technical field of materials. The nano silver copper alloy solid solution welding paste is made of, in percentage by mass, 80-90% of single-phase nano silver copper alloy particles, 2-8% of a dispersing agent, 2-8% of a dressing agent, 2-8% of a thinning agent and 2-8% of scaling powder. According to the single-phase nano silver copper alloy solid solution welding paste andthe preparation method for the single-phase nano silver copper alloy solid solution welding paste, single-silver-phase silver copper alloy nano particles are directly reduced out adopting a one-stepliquid phase reduction method, the silver copper mass ratio in the silver copper nano alloy particles is flexible and can be adjusted and controlled at will within the range of (0.1-10) : 1, the preparation method has the characteristics of being simple in method, high in production efficiency and wide in process application range, the single-phase nano silver copper alloy solid solution welding paste has excellent connection performance, the boundedness of single nano silver and single nano copper in the application process is overcome, and the single-phase nano silver copper alloy solid solution welding paste has the advantages of low-temperature connection high-temperature service, low connection pressure applying, short connection time, strong oxidation resistance, strong electromigration resistance and electrochemical migration resistance and low relative cost.

The invention, which relates to the technical field of micro-connection, provides a method for preparing a low-temperature interconnected high-temperature in-service joint by using a single-phase nanosilver-copper alloy solder paste. The method comprises the following steps: step one, placing a nano inter-metallic compound solder paste on a substrate, completing an alignment process of a to-be-soldered component, and applying a pressure; and step two, placing the system in a reflow furnace, and implementing a preheating phase, a heat preservation phase, a re-flowing phase, and a cooling phaseto complete volatilization of organic matters, uniform sintering among single-phase nano-alloy particles, and wetting and interfacial reaction of a bonding pad. According to the invention, with the single-phase nano silver-copper alloy particles, the powerful driving force is provided for the sintering process based on the excellent surface activity property of the nano particles; the low-temperature connection that is compatible with the traditional reflow soldering process and has the melting point far lower than the melting point of the block is realized; and an excellent joint with the high anti-oxidation, anti-electromigration and anti-electrochemical migration capabilities is formed. The high-temperature service of the low-temperature connection is realized while the compatibility with traditional process is high and the production efficiency is high.

The microscopic electrochemical analyzer includes power supply unit, optical microscope, electrolytic bath, video camera, computer, control software with matched with image display and editing functions. The optical microscope is connected via standard CS interface with CCD camera, the CCD camera and the computer are connected via video card, the CCD camera transmits its data to software for control and amplified display in the display, and the electrolytic bath is connected to the outer power supply to constitute the work bath for electrochemical immigration and electrochemical reaction. By means of biological microscopic technology and electrochemical immigration and electrochemical reaction technology, the present invention constitutes the instrument capable of continuous observing, photographing and analyzing electric immigration, reverse emulsion and electrochemical reaction in various polar and non-polar systems and amplifying microscopic dynamic process.

The invention provides a dust pollution circuit board insulation failure simulation detection method based on electrochemical migration. NaCl and quartz particles are selected as representative components of soluble salt and insoluble particles in dust pollutants, the insulation failure of the circuit board based on the electrochemical migration mechanism under dust pollution is simulated and detected, and the method comprises the following steps: 1, preparing a sample; cleaning a circuit board sample; quantitatively adding a NaCl solution on the surface and covering the quartz particles. 2, preparing a test environment, comprising: setting temperature and humidity; connecting the circuit board sample into a test system; a bias voltage and measurement options are set. 3, carrying out an experiment, comprising the following steps: starting bias voltage; operating the temperature and humidity box; starting a multi-channel insulation resistance test system; experimental continuing 24 hours; 4, data processing, performing morphology analysis on the failure phenomenon of the circuit board; and extracting the characteristic life and carrying out insulation failure judgment. The test method provided by the invention is simple and efficient, and the experimental principle conforms to the actual application situation.

The invention discloses micro Ag-Cu solder cream, a preparing method thereof and application. The Ag-Cu solder cream is prepared by Ag powder, Cu powder and glycerol according to the following proportion that the mass ratio of the Ag powder and the Cu powder is 2-4:1, and the mass ratio of the sum of the mass of the Ag powder and the Cu powder with glycerol is 8-12:1. The grain size of the Ag powder is 5-10 nm, and the grain size of the Cu powder is 20-60 nm. The preparing method of the Ag-Cu solder cream comprises the following steps that the Ag powder and the Cu powder are picked, ethyl alcohol is added into the Ag powder and the Cu powder, grinding is conducted, and Ag-Cu mixed powder is obtained; and glycerol is added again into the Ag-Cu mixed powder to be concocted into viscous cream, and the micro Ag-Cu solder cream is obtained. The micro Ag-Cu solder cream can be used for connecting parts of coppers. According to the specific stepsfor preparing theconnecting parts of coppers, the appropriate micro Ag-Cu solder cream is picked and evenly painted on the connecting surfaces to be connected of two copper base metal, and the connecting surfaces are closed and connected. The micro Ag-Cu solder cream is high in inoxidizability, good in electrochemical migration resistance and high in specific conductance and thermal conductivity, and a connecting head prepared through connecting of the micro Ag-Cu solder cream is ideal in cutting strength and high in reliability.

The invention provides a printed circuit board for testing electric-resistant chemical migration performances. The printed circuit board is provided with an anti-CAF (anti-conducting cation migration) performance testing graph which comprises a plurality of grooved holes in a two-two spaced manner. The grooved holes are arranged on the anti-CAF performance testing graph to replace currently-arranged drill holes, and arranging of the grooved holes is small in damages to materials when compared with arranging of the drill holes, namely, damages to glass fiber cloth of the printed circuit board can be well avoided during processing of the grooved holes, so that when decontamination and cleaning are performed, the grooved holes, not like the drill hole, are less prone to formation of big halos, and serious capillary action cannot be generated caused by damages to the glass fiber cloth, so that effective hole pitches are lengthened, and anti-CAF capability of the printed circuit board is further improved. The invention further provides a manufacturing method for the printed circuit board for testing electric-resistant chemical migration performances.

A highly thermally conductive printed circuit board prevents electrochemical migration by inhibiting elution of copper ions. The printed circuit board is a metal-base printed circuit board including a metal base plate having an insulating resin layer and a copper foil layer stacked thereon in this order. In the printed circuit board, the insulating resin layer contains a first inorganic filler made of inorganic particles having particle diameters of 0.1 nm to 600 nm with an average particle diameter (D₅₀) of 1 nm to 300 nm, and a second inorganic filler made of inorganic particles having particle diameters of 100 nm to 100 μm with an average particle diameter (D₅₀) of 500 nm to 20 μm, and the first inorganic filler and the second inorganic filler are uniformly dispersed in the insulating resin layer.

The invention relates to three asymmetric solid-state electrochemical capacitors constructed through nanometer copolyaniline and activated carbon. Sulfonated copolyaniline serves as a positive electrode active material, and the activated carbon serves as a negative electrode active material. A positive electrode is soaked in positive electrolyte gels to form a positive electrolyte gel layer; the positive electrolyte gel layer is an anode matrix with positive electrolyte being dissolved therein; the positive electrolyte is an inorganic acid; and the anode matrix is selected from polyvinyl alcohol or polyvinylpyrrolidone. A negative electrode is soaked in negative electrolyte gels to form a negative electrolyte gel layer; the negative electrolyte gel layer is a cathode matrix with negative electrolyte being dissolved therein; the negative electrolyte is neutral salt; and the cathode matrix is selected from carboxymethylcellulose, potassium polyacrylate or polyethylene oxide. Compared with the prior art, the capacitors greatly suppress electrochemical migration and effectively ensure cycling stability of the capacitors, and give play to performance advantages of a pseudocapacitor material and a electrical double-layer capacitor material to the maximum degree.

The invention discloses a copper alloy film, a protective layer after service based on the copper alloy film and a preparation method, the copper alloy film is a binary alloy, and comprises a copper element and an additive element capable of forming a positive mixed entropy with copper; the mass percentage content of the copper element is 95 to 99 wt%; the method comprises the following steps: forming a copper alloy film with positive enthalpy of mixing on a substrate; and then applying an energy field to the copper alloy film, so that the added elements are separated out and a protective layer is formed on the surface of the copper film. According to the invention, the copper alloy film with positive mixing enthalpy is adopted, the added elements in the alloy move towards the surface under the action of pressure difference, finally, the added elements cover the copper, electrochemical migration of the metal copper is inhibited, the resistance of the copper circuit board to electrochemical migration is improved, a double-element coating can be formed at a time through the overall preparation method, the process is simplified, and the reliability of the coating is improved.

Provided is a thermoelectric module capable of further suppressing electrochemical migration with a simple structure. A thermoelectric module includes: a lower substrate; an upper substrate disposed above the lower substrate so as to be opposite to the lower substrate; a plurality of p-type thermoelectric elements and n-type thermoelectric elements disposed between the lower substrate and the upper substrate; first electrodes disposed on an upper surface of the lower substrate and a lower surface of the upper substrate, and sequentially connecting the p-type and n-type thermoelectric elements alternately to form a series circuit; and a second electrode that is provided on the lower substrate and connects a thermoelectric element at an end of the series circuit to a post, in which the post includes a post body formed of nickel, and a nickel passivation film covering a side surface of the post body.

Embodiments of the present invention provide a method (1000) of assembling an electrical circuit comprising one or more copper electrical conductors, the method comprising plating (1010) a surface of the one or more conductors with a layer comprising tin; annealing the plating; applying (1020) solder to at least a portion of the one or more electrical conductors, wherein said solder comprises tin and copper; and annealing the electrical circuit.

The invention provides an electrochemical migration test method and device for power packaging, and the test method comprises the following steps: S1, printing a to-be-tested electrode pattern on a substrate through employing metal nanometer conductive ink, and obtaining a to-be-tested sample; s2, performing plasma surface treatment on the electrode pattern of the to-be-tested sample; s3, fixing the to-be-tested sample on an objective table of an optical microscope, adjusting the focal length and magnification times, and connecting the positive and negative electrodes of a power meter with the electrode of the to-be-tested sample when a clear and complete image appears; dripping liquid on a sample to be detected to form a liquid film, and starting in-situ observation by adopting in-situ observation equipment while starting a power meter to apply voltage so as to obtain an in-situ monitoring picture of an electrochemical migration process and a current and voltage change curve. According to the technical scheme, the method is easy to operate, the period is short, the device is very convenient to build, and the obtained experimental result has good observability and repeatability.

The invention discloses an anti-short-circuit high-voltage circuit board and a manufacturing method thereof in the technical field of PCB manufacturing. The manufacturing method comprises the following steps: manufacturing isolation holes between through holes with voltage difference and between through holes with voltage difference and a circuit on the high-voltage circuit board; and on the premise that the distance between the conductors is not increased and special insulating materials are not selected, a path for forming electrochemical migration between the conductors is cut off by a physical method, and the voltage resistance between the conductors is improved.

The invention provides a PCB-Cu electrochemical migration corrosion failure simulation method, and belongs to the technical field of metal electrochemical corrosion simulation. The method comprises the following steps: establishing a two-dimensional cellular space, and determining boundary conditions; determining a cellular type and a cellular neighbor type, and determining each cellular type attribute in the cellular space; setting initial distribution of a cellular space; determining a conversion rule between the cells; simulating the corrosion process and morphology change of the PCB-Cu in the voltage coupling humid and hot environment; and processing the simulation result to obtain a curve graph of related products in the PCB-Cu corrosion process. According to the simulation method provided by the invention, the PCB-Cu is taken as a prototype, the specific phenomenon that the PCB-Cu forms a large number of crystal products on the edge of the anode plate and obstructs the subsequent corrosion process in the voltage coupling humid and hot environment is simulated, the accuracy of a simulation result is improved, and a solid foundation is provided for corrosion prevention of an electronic material.

The invention relates to a preparation method of an anti-electrochemical-migrating nano-silver compound welding paste material, and belongs to the technical field of welding materials. According to the technical scheme provided by the invention, by adopting a sol compounding scheme, a palladium-nickel compound sol and silver nanoparticles are effectively compounded; through a sol-gel method, Pd atoms on the surfaces of double-metal nanoparticles are dispersed uniformly; meanwhile, nano-silver is easy to agglomerate, so that in order to prevent the agglomeration of the nano-silver, surface active agents are adopted, micelles are formed on the surfaces of silver particles in a flatly lying way so as to be used as a layer of steric hindrance layer, and the nano-silver is prevented from beingagglomerated and grown; and meanwhile, a compound sol material surface carries negative electricity, the surface of the nano-silver carries positive electricity through the surface active agents adsorbed on the surfaces of the silver particles, the surface active agents play a role in directing the deposition of compound gel particles on the surface of the nano-silver, and finally compound particles with core-shell structures are formed so as to be prevented from being agglomerated and dispersed, so that the structural strength and the dispersing performance of the material are further improved.

The invention discloses a drill bit with a single chip removal groove and double cutting edges. The drill bit comprises a drillstock (1) and a drill lip (2); the drillstock (1) and the drill lip (2) are connected through a connecting part (3); the free end of the drill lip (2) is a drill tip (4); a double-helix cutting edge groove (5) is formed in the part, close to the drill tip (4), of the drill lip (2); and the single-helix chip removal groove (6) is formed in the part, close to the connecting part (3), of the drill lip (2). The invention further discloses a method for avoiding electrochemical migration between board holes. The method comprises the steps of S01, analyzing CAM data; S02, defining and screening high-risk hole pairs; and S03, designing a drilling path. According to the drill bit with the single chip removal groove and the double cutting edges and the method for avoiding the electrochemical migration between the board holes, the generation of cracks between the holes can be reduced to the maximum extent, and therefore the aim of preventing electrochemical migration failure can be achieved.

The invention discloses a high-voltage circuit board and a manufacturing method thereof in the technical field of PCB manufacturing. The method comprises the steps: manufacturing a groove hole at a designated position of a prepreg; and stacking and pressing a plurality of prepregs with slotted holes and a substrate of which the inner layer is manufactured according to a set sequence to form a multi-layer circuit board. On the premise that the distance between the conductors is not increased and a special insulating material is not selected, a path for forming electrochemical migration between the conductors is cut off by a physical method, so that the voltage resistance between the conductors is improved.

Disclosed are an additive for suppressing electrochemical migration (ECM) in an electrical wire, and a method of inhibiting the ECM using the additive. A solution containing the ECM-inhibiting additive may inhibit creation of dendrite to prolong an ECM time. The additive as proposed may be mixed with polymer materials such as epoxy molding compound (EMC) or underfill materials used for packaging a semiconductor, or the like. Alternatively, the additive as proposed may be added to metal electrical wires to improve the reliability of semiconductor devices.