Abstract: A method for molding and soldering electrical connection pads to the electrical connection-receiving zones of electronic components or circuits includes an operation for the injection of conductive liquid alloy into a guide open at one end placed so as to face the connection-receiving zone of the component. The guide is formed by two separable parts, a mold and an injection matrix, the mold and the injection matrix including passages, with a narrowing of the guide at the level of the separation of the parts, and the parts of the guide are separated while the alloy is in the liquid state. Such a method may find particular application to, as an example, making connection pads for substrates or electronic components.

Abstract: A method of forming solder connections on a circuitized substrate having connection pads is provided. A laser ablatable solder mask material, preferably an epoxy, is degassed and then dispensed as a liquid onto the substrate over the circuitization. The surface of the solder mask material as applied is leveled, and the solder mask material is then cured to form a solder mask. Openings are laser ablated in the solder mask material to reveal those connection pads which are to receive solder to form the solder connections. Liquid solder is dispensed under pressure in a confined space into the openings as blades move laterally on top of the solder mask to fill the openings in the solder mask. The solder material is then solidified to form domed solder bumps in the openings.

Abstract: An apparatus and a method for filling high aspect ratio holes in electronic substrates that can be advantageously used for filling holes having aspect ratios larger than 5:1 are disclosed. In the apparatus, a filler plate and a vacuum plate are used in conjunction with a connection means such that a gap is formed between the two plates to accommodate an electronic substrate equipped with high aspect ratio via holes. The filler plate is equipped with an injection slot while the vacuum plate is equipped with a vacuum slot such that when a substrate is sandwiched therein, via holes can be evacuated of air and injected with a liquid simultaneously from a bottom side and a top side of the substrate. The present invention novel apparatus and method allows the filling of via holes that have small diameters, i.e., as small as 10 &mgr;m, and high aspect ratios, i.e.

Abstract: A method of fabricating a zero signal degradation solder bridge electrical connection for connecting adjacent conducting pads of a printed circuit board, and a printed circuit board having at least one of these solder bridge electrical connections. In the method, a stencil, having an opening that corresponds to the adjacent conducting pads and at least a portion of the surface area of the printed circuit board between the adjacent conducting pads, is placed on the surface of printed circuit board. Solder paste is then applied to the stencil such that the solder paste flows through the stencil opening and onto the adjacent conducting pads and at least a portion of the surface area of the printed circuit board between the pads. The stencil is then removed and the printed circuit board is subjected to reflow soldering, thereby fabricating a printed circuit board having a solder bridge electrical connector between adjacent conducting pads.

Abstract: Process for the production of at least one solderable surface in selected solder regions and of at least one functional surface in function regions differing from the solder regions on circuit carriers provided as well as of corresponding circuit carriers.

Abstract: A solder jet apparatus is disclosed. The solder jet apparatus is a continuous mode solder jet that includes a blanking system and raster scan system. The use of the raster scan and blanking systems allows for a continuous stream of solder to be placed anywhere on the surface in any desired X-Y plane. This allows for greater accuracy as well as greater product throughput. Additionally, with the raster scan system, repairs to existing soldered surfaces can be quickly and easily performed using a map of the defects for directing the solder to the defects.

Abstract: Apparatus and methods for removing excess solder from connections on electrical circuits is disclosed. The apparatus and methods comprise providing an enclosure in which the circuits with excess solder are heated to a temperature above the melting point of the excess solder. There is also provided a clamp or mounting device for securing the electrical circuits with the excess solder such that they can be spun up to a sufficient rotating speed to cause the excess solder to be spun off the connections by centrifugal force. The enclosure includes an annular solder collecting pan for collecting the excess solder as it is removed from the circuit board.

Abstract: A bath apparatus 12 reserves a liquid 13 as a heating medium and includes an input partition bath 31, a first intermediate partition bath 32, a heat partition bath 33, a second intermediate partition bath 34 and a removing partition bath 35 that are divided by gates 21 through 24 and sequentially arranged in a direction in which a printed board assembly where components are loaded onto a printed board moves. The temperatures of liquids 13-31 and 13-32 in the input partition bath 31 and the first partition bath 32 are a preheating temperature. The temperature of a liquid 13-33 in the heat partition bath 33 is a soldering temperature. The gate 21 is gradually opened while the printed board assembly 11 is located in the first intermediate partition bath 32 and before the printed board assembly 11 is conveyed into the heat partition bath 33.

Abstract: For dispensing solder on a substrate, a soldering wire and a forming gas heated to a predetermined temperature are fed to a mixing chamber of a two-component nozzle so that, in the mixing chamber, solder is melted off and carried with the gas stream. The solder blown out of the two-component nozzle settles on the substrate. The two-component nozzle is moved or swivelled relative to the substrate in order to distribute the solder over a predetermined area of the substrate.

Abstract: An improved die placement and bonding apparatus with bleed out control for attachment of a die onto the prescribed surface of a leadframe. The apparatus contains a bond frame provided with an alignment mechanism, and a die placement mechanism. The frame has a perimeter side wall with a base defining a predetermined area therein, with dimensions larger than the dimensions of the die. The side wall is used to provide a solder liquid tight seal when it is placed on a prescribed surface of the leadframe. The alignment mechanism is coupled to the frame and allows the frame to be properly aligned with the leadframe before it is lowered onto the prescribed surface. The die placement mechanism is used for delivering and placing the die onto the liquid solder on the leadframe within the side wall.

Abstract: In a soldering method for soldering an electronic component including a palladium or palladium alloy layer formed on a surface of the electronic component and also including a soldering lead terminal onto a printed wiring board including a soldering land and plated through hole, a solder layer containing tin and zinc as main components is formed on the surfaces of the land through hole by a HAL treatment. The lead terminal is inserted and mounted in the through hole. The printed wiring board is brought into contact with jet flows of a solder containing tin and zinc as the main components to thereby supply a solder to the land and through hole.

Abstract: Apparatus and methods for applying atomized pulsed streams of flux to a surface such as a printed circuit board. The flux is applied discretely in selected locations and at selected thickness based upon pulse rate, fluid pressure, air pressure and traverse speed. The apparatus consists of a precise orifice with a surrounding air passage for atomizing and focusing the flux at a discrete location on the surface. Controls are incorporated for selecting, controlling and monitoring the flux deposition amount and location, for coordinating with the transport motion system, for integrating with the adjacent air flow and for selecting the atomized or non-atomized method of application.

Abstract: A purge ring is provided for supplying a shield gas to the root side of a tubular article to be welded. The purge ring includes a generally U-shaped split-cylindrical body having an adjustable circumference together with slotted side walls connected by a bottom wall, the slotted side and bottom walls defining an isolation zone and a slip joint for insertion or retrieval of the purge ring in relation to the tubular article to be welded.

Abstract: A solder jet apparatus is disclosed. The solder jet apparatus is a continuous mode solder jet that includes a blanking system and raster scan system. The use of the raster scan and blanking systems allows for a continuous stream of solder to be placed anywhere on the surface in any desired X-Y plane. This allows for greater accuracy as well as greater product throughput. Additionally, with the raster scan system, repairs to existing soldered surfaces can be quickly and easily performed using a map of the defects for directing the solder to the defects.

Abstract: A new solder bath apparatus applied to the soldering furnace is disclosed herein. The solder bath is used for containing molten solder. And a nozzle base is located in the solder bath to flow molten solder upwards. An enclosing frame with axial horizontal pillars mounted on the two terminal sidewalls thereof is put around the nozzle base. Besides, a nozzle manufactured with two bearing pedestals on two terminal sidewalls responsive to the pillars is put around the enclosing frame. Thus, the nozzle can rotate about the axial pillars for adjusting the outlet direction thereof.

Abstract: A system for fine feature spray deposition includes a substrate platform for supporting a substrate on which the features are to be deposited. A spray assembly is provided which includes a spray source for providing a stream of material to be deposited on a substrate, a collimator which is positioned in a path of the stream from said spray source and an aperture assembly, which is positioned downstream of the collimator with respect to the spray source and above the substrate platform. The aperture assembly defines at least one opening to pass a portion of the stream of material onto a surface of the substrate. A drive mechanism is provided which is coupled to at least one of the spray assembly and the substrate platform for inducing relative motion there between. A controller is coupled to the spray assembly and the drive mechanism to control the relative motion and the stream of material. The system allows fine features to be printed directly on a substrate with requiring a predefined mask.

Abstract: A soldering machine includes a solder vessel, an electromagnetic pump, and a nozzle. The solder vessel stores molten solder, and the electromagnetic pump moves the solder by generating electromagnetic force. The electromagnetic pump is submerged below the liquid surface of the solder. The nozzle ejects the solder in the solder vessel onto an object, such as a printed circuit board. Accordingly, the generated heat from the electromagnetic pump is conducted to the solder in the solder vessel, and the solder can be heated to a higher temperature than in the conventional soldering machine.

Abstract: An integrated solder bump deposition method and apparatus that enables solder bumps to be lithographically formed on a substrate. The apparatus comprises a plurality of electrolyte cells, and etch/clean/passthrough station and a reflow chamber.

Abstract: A tool for applying solder paste to leadless chips has recesses adapted to receive the leadless chips. Apertures in each recess are arranged according to pads on the leadless chip. With the chips held in the recesses, solder paste is applied in the apertures.

Abstract: In devices for solder-ball bonding of a bonding pad of a slider of a head gimbal assembly to a lead pad of a lead, although a device that can perform (1) the supply of solder balls, (2) the positioning of a solder ball, (3) the blowing of nitrogen gas N2, and (4) the melting of the solder ball by laser radiation in one device is available, there are various problems that cannot improve the efficiency of laser radiation, maintenance, or operation efficiency, due to spatial restriction, difficulty of weight reduction, or fixed operation procedures. A solder-ball holder and an optical device are configured separately, and a vacuum pad is provided. A solder ball held in a solder-ball holding hole of the solder-ball holder is transported by the vacuum pad to a connecting portion of a head gimbal assembly, and solder reflow is carried out by the optical device.

Abstract: An apparatus and method for manufacturing solder balls used for an electrical and/or mechanical connection between a semiconductor chip and a substrate are provided. The apparatus includes a melting furnace having a nozzle through which a molten solder paste flows and drops, for producing solder balls; a vibrating mechanism attached to the nozzle of the melting furnace, for applying vibration to the nozzle; and a vibration controlling mechanism for controlling the vibration frequency of the vibrating mechanism to adjust the size of the solder balls dropped from the nozzle. The method includes the steps of setting a vibration frequency according to a desired solder ball size, applying vibration to a nozzle with the set vibration frequency, making the molten solder paste flow through the nozzle to manufacture solder balls of a predetermined size according to the vibration frequency, and measuring the size of the manufactured solder balls.

Abstract: A delivery system a soldering paste to an electronics package includes a pressurized supply of via fill paste and a pressure head attached to the pressurized supply of via fill paste. The pressure head includes a main body and a wear portion. Attached to the wear portion is a gasket positioned along one surface of the pressure head. The pressure head also includes a flow dispersion regulator which includes a feed tube positioned within the main body, the feed tube has a plurality of flow regulating openings. The flow regulating openings in the feed tube are sized to maintain a substantially constant pressure at each of the flow regulating openings. Positioned between the main body and the wear portion is a flow equalization grid. The flow equalization grid includes a multiplicity of openings. Attached to the wear element is a gasket. The pressure source preferably includes a ram press.

Abstract: An arrangement for feeding soldering material into a space between a bolt and rock includes a sleeve-like nozzle which can be pushed tightly against a feed chamber on the rock bolt so that a feed hole in the feed chamber is connected to the inner space of the nozzle. The arrangement further includes a device for placing the nozzle around the feed chamber so that soldering material can be fed from the inner space of the nozzle into the drill hole.

Abstract: An array of solder balls is formed on a first substrate for interconnecting with conductive sites on another substrate. A ball pickup tool picks up balls with a vacuum suction from a fluidized ball reservoir and utilizes a puff of gas to release the solder ball(s) carried thereon to conductive sites of a substrate for bonding thereto. In another embodiment, the bond pads of a substrate are coated with a flux or adhesive and lowered into a fluidized ball reservoir for direct attachment of solder balls.

Abstract: There is disclosed a solder ball pitcher supplying a large number of solder balls stored in a solder ball housing chamber in a row into a solder ball supply passage unit through a taper portion, and then delivers the solder balls in sequence through a solder ball supply opening at the tip end of the solder ball supply passage unit by a swing motion of the release link in case of allowing a release lever reciprocated by a pusher and a compressive coil spring to translate by a parallel link composed of the release link and a follower link.

Abstract: The present invention discloses a method and apparatus for forming solder bumps by a molten solder screening technique in which a flexible die head constructed of a metal sheet is utilized for maintaining an intimate contact between the die head and a solder receiving mold surface. The flexible die head, when used in combination with a pressure means, is capable of conforming to any curved mold surface as long as the curvature is not more than 2.5 &mgr;m per inch of die length.

Abstract: Ultra-small satellite droplets of molten metal, generated from capillary stream break-up, are selectively directed to predetermined locations on a substrate. The satellite droplets are produced at a high rate and are highly uniform because of the nature of capillary stream break-up. Applied harmonic disturbances are used to control and generate the satellite and parent droplets. The satellite droplets are electrostatically charged on a droplet-by-droplet basis and are then deflected by, e.g., an electric field to predetermined locations on a substrate. The substrate is moveable, attached to an x-y table, for facilitating the placement of satellite droplets on the substrate. The satellite droplets can be placed in individual locations on the substrate (e.g., for forming a ball grid array) or can be overlapped to form conductive traces. Because the satellite droplets have small diameters, these traces may have correspondingly small widths or pitches.

Abstract: An integrated solder bump deposition method and apparatus that enables solder bumps to be lithographically formed on a substrate. The apparatus comprises a plurality of electrolyte cells, and etch/clean/passthrough station and a reflow chamber.

Abstract: Apparatus for improved electronic substrate via and thru-hole filling, particularly through the use of drilled stand-offs formed by control-depth drilling oversized non-thru-holes and the use of inserted support pillars to prevent sagging of the substrate during filling. In particular: (1) a via fill stand off adapted for use with a substrate comprising at least two via holes to be filled, each of the via holes having a diameter of X mils, the standoff comprising at least one recess formed by control-depth drilling of holes having a diameter at least 12X mils; and (2) a via fill standoff adapted for use with a substrate comprising at least one via hole to be filled, the standoff comprising: at least one recess; and at least one support pillar positioned within the recess wherein the support pillar is not an integral part of the standoff.

Abstract: A flux and solder tool includes a housing configured to store both flux and solder. A nozzle extends from the housing. A pump feeds solder from the housing through the nozzle. A wire drive feeds solder from the housing through the nozzle.

Abstract: A method and apparatus for desoldering electronic components from a substrate. A vacuum is used to enhance the flow of a hot gas under an electronic component to reflow the solder connections attaching the electronic component to a substrate. Water vapor is added to the hot gas to increase the heat capacity of the hot gas. A system for periodically changing the direction of flow of the hot gas and vacuum under the electronic component is used to uniformly heat the solder connections. A method and apparatus for depositing underfill material between an electronic component and the substrate on which the electronic component is mounted. A vacuum is applied to enhance the flow of underfill material into the space between the electronic component and the substrate.

Abstract: Disclosed is a method and an apparatus for soldering a base material. A binary solder essentially consisting of tin and a metal which can form an eutectic alloy with tin and which is exclusive of lead is prepared. The content of other metallic components is 0.1% by weight or less and the content of oxygen is 100 ppm or less. The binary solder is melted in a non-oxidizing environment and dispensed to the base material in an atmosphere in which the oxygen content is 2,000 ppm or less, to solder the base material with the binary solder. The soldering apparatus comprises an oscillator for supplying oscillatory wave energy having frequency of 15 KHz to 1 MHz to the base material. The soldering apparatus can also be realized in the form of a soldering nozzle or a soldering iron.

Abstract: A method is provided for manufacturing a piezoelectric actuator having a piezoelectric element and a lead wire for supplying a drive signal to the piezoelectric element. A melt material is immersed into a fusing agent. A quantity of the material and the fusing agent is supplied to a transfer plate and then adjusted. A preselected quantity of the melt material and the fusing agent is then transferred preselected quantity of the melt material and the fusing agent is supplied from the transfer tool to the lead wire. The melt material is then welded on the lead wire and on the piezoelectric element to thereby connect the lead wire to the piezoelectric element.

Abstract: A solder jet apparatus is disclosed. The solder jet apparatus is a continuous mode solder jet that includes a blanking system and raster scan system. The use of the raster scan and blanking systems allows for a continuous stream of solder to be placed anywhere on the surface in any desired X-Y plane. This allows for greater accuracy as well as greater product throughput. Additionally, with the raster scan system, repairs to existing soldered surfaces can be quickly and easily performed using a map of the defects for directing the solder to the defects.

Abstract: A soldering device and method includes the steps of forming a solder melting pot by assembling plural trowel members, supplying a solder tip to the solder melting pot, and sequentially repeating the operation for supplying the molten solder to the respective soldering point. In the improvement, an additional heating portion which comes close to the solder melting pot is formed near or with the trowel members, and the soldering point to which molten solder has already been supplied by the prior molten solder supplying operation is additionally heated during the supplying operation of the next soldering point. The trowel members are used to simultaneously perform the operation for supplying the molten solder and another operation for additionally heating the soldering point to which the molten solder has been supplied. A plurality of points to be soldered aligned at predetermined intervals are efficiently soldered.

Abstract: A stroke and pressure adjusting device is used for the soldering process of a soldering machine which has a driving device for driving a soldering device of the soldering machine to solder, and the driving device has a driving shaft on which the stroke and pressure adjusting device is attached. The stroke and pressure adjusting device comprises a thread sleeve mounted on the driving shaft of the driving device, a slider mounted on the thread sleeve, and a spring mounted between the slider and the driving device, wherein the distance between the thread sleeve and the driving device is adjustable so as to adjust the stroke of the driving device, the distance between the slider and the driving device is adjustable and the distance between the slider and the driving device is adjustable so as to adjust the elastic force generated by the spring, thereby adjusting the operating pressure of the driving device.

Abstract: A delivery system a soldering paste to an electronics package includes a pressurized supply of via fill paste and a pressure head attached to the pressurized supply of via fill paste. The pressure head includes a main body and a wear portion. Attached to the wear portion is a gasket positioned along one surface of the pressure head. The pressure head also includes a flow dispersion regulator which includes a feed tube positioned within the main body, the feed tube has a plurality of flow regulating openings. The flow regulating openings in the feed tube are sized to maintain a substantially constant pressure at each of the flow regulating openings. Positioned between the main body and the wear portion is a flow equalization grid. The flow equalization grid includes a multiplicity of openings. Attached to the wear element is a gasket. The pressure source preferably includes a ram press.

Abstract: There are provided a chamber having openings which are opened to an outer air and through which a solder-adhered object w is passed and having a heating/melting area and carrying areas arranged adjacent to the heating/melting area, a carrying mechanism for carrying the solder-adhered object w into the heating/melting area, a formic-acid supplying means for supplying a formic acid into the heating/melting area, an exhausting means for exhausting a gas from the heating/melting area and its neighboring area to lower a pressure in the heating/melting area rather than an outer air, heating means for heating directly or indirectly the solder-adhered object w in the heating/melting area, and air-stream suppressing means for disturbing a gas flow between the heating/melting area and the carrying areas.

Abstract: A solder jet apparatus is disclosed. The solder jet apparatus is a continuous mode solder jet that includes a blanking system and raster scan system. The use of the raster scan and blanking systems allows for a continuous stream of solder to be placed anywhere on the surface in any desired X-Y plane. This allows for greater accuracy as well as greater product throughput. Additionally, with the raster scan system, repairs to existing soldered surfaces can be quickly and easily performed using a map of the defects for directing the solder to the defects.

Abstract: A flux and solder tool includes a housing configured to store both flux and solder. A nozzle extends from the housing. A pump feeds solder from the housing through the nozzle. A wire drive feeds solder from the housing through the nozzle.

Abstract: An embodiment of the present invention includes a disposable print head for ejecting controlled amounts of liquid (e.g., solder) at a high rate onto the surface (e.g., an integrated circuit) in close proximity to the ejecting source. The embodiment involves the use of a controlled burst of gas that is developed by rapidly heating a metallic hydride film with a laser to disassociate the hydrogen therefrom. The pressure created by the burst of hydrogen gas is used to eject an amount of a liquid (e.g., a solder) from an appropriate conduit that is fed liquid from a reservoir. The surfaces in the print head that contact the liquid are coated to assist in priming the print head for a subsequent ejection event.

Abstract: Apparatus for use in wave soldering applications can include an adjustable wing device, a front gate and/or a mounted member. Each of these components are easily adjustable, thereby improving the quality of the soldered product and allowing for improved process efficiency and decreased downtime of the wave soldering equipment.

Abstract: A bump forming apparatus comprises a container for retaining therein a solder melt, a solder forming member having a side wall portion and a ceiling portion which form, above a substrate's flat surface, a chamber for receiving therein the solder melt. The solder forming member also includes a height regulator portion provided on an exterior of the side wall portion and having a flat surface for restricting the height of the solder melt during formation. Heating means for heating the solder melt may also be provided. A hole in the solder forming portion allows solder melt to flow from the container to the chamber. Pressurizing means for pressurizing the solder melt in the container to thus expedite passage of solder melt into the chamber of the forming member may be used. Depressurization means for reducing the inside pressure of the container to cause the unused metal to return from the chamber into the container may also be used.

Abstract: A system and method for forming bumps on an integrated circuit including a scanning direct laser imager employed to selectably expose a photosensitive layer deposited on an integrated circuit substrate, thereby to define regions overlying selected portions of the substrate, a developer developing said photosensitive layer to form apertures in the photosensitive layer at the defined regions, and a solder applicator applying a solder composition to the apertures to define solder bumps on the integrated circuit at selected portions thereof.

Abstract: An automatic dross removal apparatus, which can be used with a solder wave apparatus, is provided, that generally includes a reservoir having a cavity for containing liquid solder, dross removal apparatus having a first end extending within the cavity of the reservoir for removing dross on the surface of the liquid solder, and a motor engaged with the dross removal apparatus. In one embodiment of the invention, the dross is automatically removed by a conveyor driven by a motor. In another embodiment of the invention, the dross is automatically removed by a motor driven receptacle. Means for moving the dross from one part of the solder reservoir to another, such as a pump, can be included. Preferably, a computer is used to control the automatic dross removal. The dross can be placed in a dross separation device which can include apparatus for processing the dross to remove any remaining solder.

Abstract: A filling system includes a pressurized source of fill material and a pressure fill head wherein the fill head also includes a heating element positioned so as to transfer heat to fill material passing through the fill head. A method of filling holes using a fill material passing through a pressure fill head includes the steps of causing fill material to enter the fill head\, modifying the viscosity of the fill material while it is within the fill head, and causing the modified viscosity fill material to exit the fill head and enter at least one hole.

Abstract: An assembly is disclosed that includes an etched hole-fill standoff; a tooling plate contacting the etched hole-fill stand-off, the stand-off and tooling plate being aligned to each other; a device having holes to be filled removably contacting the stand-off, the stand-off and device being aligned to each other; the device and the stand-off each having at least one hole, the hole of the device being aligned with the hole of the stand-off. An assembly is also disclosed comprising an etched hole-fill standoff, the stand-off comprising an etched layer bonded to a non-etched layer. A method of filling holes in a substrate having a plurality of holes to be filled includes the steps of providing an etched hole-fill stand-off, aligning the stand-off to a tooling plate, aligning the substrate to the stand off and placing the substrate in contact with the stand-off, and filling the plurality of holes of the substrate.

Abstract: A BGA ball mount line with a dual in-line mounter flowing into one reflow oven and one in-line cleaner. The dual in-line mounter comprises a first ball mount cell and a second ball mount cell. The second ball mount cell is parallel to and a mirror image of the first ball mount cell. The first ball mount cell and the second ball mount cell can be run by a single operator located between them. In one embodiment of the invention, the BGA ball mount line with dual in-line mounters is implemented in three phases to provide a smooth transition. In the first phase, a proto-line is set-up with a first ball mount cell, a loading cell, a diverter cell, and an unloading cell, to optimize the first ball mount cell. In the second phase, a reflow oven and a flux cleaner are added to form a production line. In the third phase, a second ball mount cell is added to form a BGA ball mount line with a dual in-line mounter.

Abstract: A combined welders tool, comprising a tool body, a striker head with a striker surface on one side, and a file on the other side, and one or more tip cleaning tools coupled to the tool body.

Abstract: An apparatus for manufacturing a plug and the manufacturing method. The method includes the following steps. A baseplate located in the bottom of a closed printing chamber is provided. A printed circuit board and a stencil are mounted on the baseplate in sequence. The stencil is aligned to the printed circuit board. An amount of preheated paste is placed on the stencil. A pressure of the closed printing chamber is adjusted to a first pressure. A printing step is performed to form plugs in the printed circuit board. The pressure of the closed printing chamber is adjusted to a second pressure to remove voids trapped in the plugs. The pressure of the closed printing chamber is adjusted to a third pressure. A scraping step is performed to remove the redundant paste.