269 results about "Stencil printing" patented technology

A voltage variable material (“VVM”) including an insulative binder that is formulated to intrinsically adhere to conductive and non-conductive surfaces is provided. The binder and thus the VVM is self-curable and applicable in a spreadable form that dries before use. The binder eliminates the need to place the VVM in a separate device or to provide separate printed circuit board pads on which to electrically connect the VVM. The binder and thus the VVM can be directly applied to many different types of substrates, such as a rigid FR-4 laminate, a polyimide, a polymer or a multilayer PCB via a process such as screen or stencil printing. In one embodiment, the VVM includes two types of conductive particles, one with a core and one without a core. The VVM can also have core-shell type semiconductive particles.

A printing system comprising a stencil printing apparatus and a digital printing apparatus for high speed printing of images having details of high resolution, rich colors, or variability, optionally also comprising a wetting apparatus operative to wet at least a part of the printed object prior to the digital printing.

Systems and methods for implementing hybrid, closed-loop control that generates control values for processes defined by a limited number of function evaluations and large amounts of process and measurement noise. The described control system is applied to a stencil printing process for applying solder paste to an electronic medium such as a printed circuit board or semiconductor wafer. The control system is defined by a hybrid approach. A first, coarse algorithm is used to rapidly produce the value of a stencil printer control value resulting in a solder paste deposit having a volume within predetermined acceptable limits. After the coarse algorithm no longer produces solder paste deposits closer to a desired volume, a second, more refined estimator is used to fine tune the process. An additional transitional algorithm may be added between the coarse algorithm and refined estimator. The coarse algorithm may be implemented with a constrained-conjugated gradient search, and the refined search may be a implemented using a least-squares affine estimator or a quadratic estimator. The transitional algorithm may be implemented using a block version of a least-squares affine estimator.

A substrate for a pre-soldering material and a fabrication method of the substrate are proposed. The substrate having at least one surface formed with a plurality of conductive pads is provided. An insulating layer is formed over the surface of the substrate in such a way that a top surface of each of the conductive pads is exposed. Next, a conductive film and a resist layer are formed in sequence on the insulating layer and the conductive pads, wherein a plurality of openings are formed in the resist layer to expose a part of the conductive film above the conductive pad. Then, a pre-soldering material is deposited over the conductive pad by stencil printing or electroplating process.

Disclosed is a multi-layer paper suitable as a material for preparing heat-sensitive stencil printing masters. The multi-layer paper is produced by combining a plurality of thin paper layers by paper making. The multi-layer paper has a peel strength of 10 N/m or less and may be delaminated into at least two tissue sheets.

A stencil printing machine has a printing drum having a cylindrical circumferential wall adapted to receive a perforated stencil sheet wrapped on an outer circumferential surface thereof and driven to rotate around a central axis thereof the circumferential wall having an opening portion with many through holes formed therein, a non-opening portion formed around the opening portion, and at least one recessed portion formed in at least one part of the opening portion adjacent to the non-opening portion in an axial direction of the circumferential wall; an ink supplying roller situated in the printing drum for supplying ink to an inner circumferential surface of the cylindrical circumferential wall of the printing drum; and a press roller situated adjacent to the printing drum and being urged against the outer circumferential surface of the cylindrical circumferential wall of the printing drum.

A stencil printing machine has a rotatable printing drum including an outer peripheral wall of ink impermeable material. A stencil paper is mounted on the surface of the outer peripheral wall. An ink supplying mechanism includes an ink supplying unit in the outer peripheral wall of the printing drum. The ink supplying mechanism supplies ink from the ink supplying unit to the surface of the outer peripheral wall. A pressure roller presses a fed print sheet against the outer peripheral wall. An ink recovering mechanism recovers ink which has flown out of a maximum printing area of the outer peripheral wall of the printing drum. A pressing mechanism presses the stencil paper against the outer peripheral wall of the printing drum.

A stencil printed encapsulant material is provided for use in protecting electrical components in thermal ink jet printhead cartridges. A method of applying an encapsulant material to an ink jet print cartridge by stencil printing is also provided. The method includes providing a stencil having at least one aperture, providing an ink jet cartridge and stencil printing an encapsulant material onto a portion of the ink jet print cartridge thereby forming a layer of encapsulant material to protect electrical components or other printhead components.

A reflow process welding method includes the steps: firstly, printing solder paste on a bottom plate through metal stencil printing; secondly, performing reflow welding for the bottom plate printed with the solder paste, forming an alloy welding layer on the bottom plate, and attaching soldering flux separated out from the solder paste on the surface of the bottom plate; thirdly, cleaning the bottom plate and removing the soldering flux separated out from the solder paste on the surface of the bottom plate; fourthly, coating the surface of the alloy welding layer with the soldering flux, and placing a workpiece to be welded on the alloy welding layer coated with the soldering flux; fifthly, performing reflow welding again. The size of the solder paste is same as that of the workpiece to be welded. The melting-point temperature of the solder paste is reference temperature N DEG C. Compared with the prior art, the process method is more convenient to operate and lower in cost, pollution caused by the soldering flux in the reflow process is avoided, and the method is particularly applicable to surface welding with a large-area contact surface.

A water-in-oil type emulsion ink composed of 10–90% by weight of an oil phase and 90–10% by weight of an aqueous phase. The oil phase contains an esterified vegetable oil (an esterified vegetable oil obtained by recycling and esterifying edible waste oil such as soybean methyl ester, soybean butyl ester, or tall oil butyl ester).

A method for fabricating a circuit board having a conductive structure is disclosed. The method includes: forming first and second insulating protective layers respectively on first and second surfaces of a circuit board; forming a conductive layer on the first insulating protective layer and the openings; forming first and second resist layers on the conductive layer and the second insulating protective layer respectively; forming first electrically connecting structures by electroplating on the exposed conductive layer over a plurality of first and second electrically connecting pads in openings of the first resist layer; removing the first and the second resist layers and the conductive layer covered by the first resist layer; and forming second electrically connecting structures by stencil printing on the conductive layer over the second electrically connecting pads on the first surface and on a plurality of third electrically connecting pads of the second surface of the circuit board.

The invention provides a printing device capable of ensuring a larger stencil adsorption area during printing. The printing device of the present invention includes: a pair of clips (31a), (31b) that clamp and hold the substrate (W) from both sides; when the substrate is held by the clips, a positioning device ( 41a, 41b); in the state that the positioning device (41a, 41b) is withdrawn from the substrate to the side, the stencil (51) arranged on the substrate held by a pair of clips (31a, 31b); Sliding on the stencil, the solder (S) on the stencil is spread and coated on the squeegee (61) on the substrate (W). A stencil (51) is placed on the positioning device in the retracted state, and a positioning device side suction device (45) for absorbing the stencil (51) is provided on the upper surface of the positioning devices (41a, 41b).

The present invention relates generally to a new process of cleaning of objects that relate to semiconductor fabrication processes, such as, for example, conductive paste screening in the production of multilayer ceramic substrates and composite solder paste by stencil printing in electronic circuit assembly. Specifically, this invention is concerned with removing a metal/polymer composite paste from screening masks and associated paste making and processing equipment used in printing conductive metal pattern onto ceramic green sheet in the fabrication of semiconductor packaging substrates. This invention is also concerned with cleaning of solder paste residue from stencil printing equipment used in electronic module assembly surface mount technology for SMT discretes, solder column attachment, and BGA (Ball Grid Array) attachment on ceramic chip carrier or for screening solder paste onto printed circuit board. More particularly, this invention is concerned with cleaning of paste residue from metal, ceramic, and plastic substrates by a non-alkaline semi-aqueous cleaning method employing high boiling propylene glycol alkyl ether or mixtures of propylene glycol alkyl ether and propylene glycol solvents.

The present invention provides a continuous process for producing catalyst-coated polymeric electrolyte membranes and membrane electrode assemblies for fuel cells. The process of the invention uses an ionomer membrane having a polymeric backing film on the back side. After the first coating step, the membrane is dried, during which the residual solvent may be almost completely removed. After this, the polymeric backing film is removed and the back side of the membrane is coated in a second step. The front and back sides of the membrane can be coated by various methods, such as screen printing or stencil printing. Two gas distribution layers are applied to the two sides of the catalyst-coated membrane to produce a 5-layer membrane electrode assembly. The membrane electrode assemblies are used in polymeric electrolyte membrane fuel cells and in direct methanol fuel cells.

A stencil printing method and apparatus for printing paste material in a given pattern on a substrate from a paste dispenser through a stencil to define the stencil pattern on a substrate. The apparatus is provided with a cleaning module that can be moved against the printing face of the stencil and moved, along a given path beneath the stencil, for cleaning the printing face of the stencil. The cleaning module includes a blade assembly mounted there on transverse to the path of movement of the cleaning module. The print apparatus further including selectively operable means for actuating the blade assembly during a select cleaning cycle to engage the leading end of its blade with the underside of the stencil as the cleaning module is passed beneath said stencil whereby the leading edge of the blade scrapes debris from the underside of said stencil. The stencil printing and cleaning method of the invention uses the steps of: dispensing a paste material through a stencil onto a substrate surface to define a given pattern thereon; and passing a cleaning module, provided with a scraping blade that can be extended above the module to contact the lower surface of the stencil to clean the underside thereof when the leading edge of the blade is in contact with the underside of the stencil.

The invention provides a material for an RFID (Radio Frequency Identification) antenna conductive pattern. The material for the RFID antenna conductive pattern has the following specific characteristics that the material is metal nano-particles which are of core-shell structures, wherein the inner cores are Cu particles of about 50 nm, and an Ag layer coats the surfaces of Cu through a composite method of displacement and chemical deposition; Cu@Ag nano-particles, absolute ethyl alcohol and deionized water are mixed to prepare conductive printing ink with the solid content of about 70 percent;the material is obtained through metal stencil printing and sintering. Antenna patterns with different thicknesses can be manufactured by the material by adopting metal stencil printing so as to meetdifferent impedance requirements of antennae of various frequency bands. The Cu@Ag nano-particles have the characteristics of low impedance, high conductivity, controllable Ag layer thickness and thelike; compared with Cu conductive printing ink, the Cu@Ag nano-particles have high oxidation resistance; compared with pure Ag or Au conductive printing ink, the cost is greatly reduced; optimal sintering performance can be realized by controlling the thickness of the Ag layer; moreover, a preparation process of the material is simple and convenient; a printing ink solvent is environment-friendlyand renewable, and has a very great application prospect in the field of conductive printing ink for the RFID antenna.

In the disclosed invention, when watermark print is set during printing, the printer driver makes a secret operation setting for holding the secret of print data accordingly, and transmits this print data to the stencil printing machine. Therefore, even if the printing of the stencil printing machine is remotely operated, it is possible to prevent an inadvertent failure to set a secret operation and to keep the secret of print data.

A printing device comprising a stencil printing device which is excellent in operativity, in which a print drum with UV ink and non-UV ink can be used in a single stencil printing device. The printing device has a stencil printing control device and UV irradiation control device in which a drum unit ink type identifying sensor, which detects whether the print drum attached to the stencil printing device main body is a print drum unit for UV ink or a drum unit for non-UV ink, is used to operate at least a UV lamp, of the UV lamp and a UV auxiliary lamp, and to irradiate UV light when attachment of the drum unit for UV ink is detected, or to stop the operation of the UV lamp and UV auxiliary lamp when attachment of the print drum unit for non-UV ink is detected.

The invention relates to a power module manufacturing method for connecting nano-silver soldering paste with bare DBC (Direct Bonding Copper). The method comprises a cleaning process, a soldering paste printing process, a chip mounting process and a sintering process. In the cleaning process, the bare DBC is cleaned by adopting ultrasonic oscillation. In the soldering paste printing process, the nano-silver soldering paste is printed by adopting metal stencil printing, and nano-silver is printed twice. In the chip mounting process, chip mounting is performed by adopting a chip mounter. In thesintering process, sintering is performed by adopting a vacuum reflow furnace to obtain an oxygen-free atmosphere of formic acid, and a sintering temperature and a heating rate are controlled. The dense connection between the nano-silver soldering paste and the bare DBC can be realized and the bare DBC can be prevented from being oxidized. No special equipment is required; the treatment process isconvenient and easy; the process is simple; a power chip can be connected with a bare copper substrate or a copper-clad substrate through the nano-silver soldering paste; the reliability of subsequent lead bonding is ensured; the reliability of a power module is improved; and the application of the nano-silver soldering paste to the power semiconductor module packaging is greatly facilitated.