Abstract: A method for fabricating a printed circuit board includes the steps of: fabricating a printed circuit board having at least one collapsed portion; depositing a first solder resist in the collapsed portion; exposing the first solder resist-coated printed circuit board at a pressure lower than atmospheric pressure for a predetermined time; coating a second solder resist on the entire surface of the printed circuit board; and drying and hardening the first and the second solder resists. With this method, when a solder resist is coated, since an air space does not remain in a blind via hole, the reliability of the attachment between a printed circuit board and the solder resist layer is increased.

Abstract: A conductive adhesive material characterized by metallurgical bonds between electrically-conductive particles dispersed in a polymer matrix of the material. The polymer matrix has a fluxing capability when heated to reduce metal oxides on the surfaces of the particles. At least the outer surfaces of the particles are formed of a fusible material, so that sufficiently heating the conductive adhesive material will reduce metal oxides on the particles, and at least partially melt the fusible metal, enabling the particles to metallurgically bond to each other and to metal surfaces contacted by the adhesive material.

Abstract: A metal foil connection of first and second metal foils having a thickness of less than 0.05 mm includes a connecting point in which the metal foils are brazed to one another. The connecting point forms a wedge which is filled with brazing medium. A mass of the brazing medium, and a mass of sections of the metal foils which the brazing medium contacts in the wedge, have a given ratio. A honeycomb body, a brazing medium particle fraction and a method for manufacturing metal foil connections with a thickness of less than 50 micrometers, are also provided.

Abstract: A metal foil connection of first and second metal foils having a thickness of less than 0.05 mm includes a connecting point in which the metal foils are brazed to one another. The connecting point forms a wedge which is filled with brazing medium. A mass of the brazing medium, and a mass of sections of the metal foils which the brazing medium contacts in the wedge, have a given ratio. A honeycomb body, a brazing medium particle fraction and a method for manufacturing metal foil connections with a thickness of less than 50 micrometers, are also provided.

Abstract: Sn—Zn alloy is plated on at least one of a first metallic member and a second metallic member, Sn—Ag alloy is used as a solder, the first metallic member and the second metallic member are connected by the solder, and a connection structure of metallic members is therefore produced. Heat degradation of plating and the contact corrosion between solder and plating can thereby be prevented, solderability can be improved, and qualities such as corrosion resistance and connecting strength at the connection structure can be improved.

Abstract: In accordance with the invention a reactive multilayer foil is fabricated by providing an assembly (stack or multilayer) of reactive layers, inserting the assembly into a jacket, deforming the jacketed assembly to reduce its cross sectional area, flattening the jacketed assembly into a sheet, and then removing the jacket. Advantageously, the assembly is wound into a cylinder before insertion into the jacket, and the jacketed assembly is cooled to a temperature below 100° C. during deforming. The resulting multilayer foil is advantageous as a freestanding reactive foil for use in bonding, ignition or propulsion.

Abstract: A pair of soldering irons are fixed to a sliding plate at a predetermined interval. The soldering irons are integrally moved so as to reciprocate in a rectangular direction relative to a conveyor belt. One of the soldering irons is conveyed to a working position of the conveyor belt and the other of them is separated from the conveyor belt. While one of the soldering irons solders a circuit board, the other is cleaned. The circuit board has a slit into which a metal plate is inserted and soldered. For the slit, a soldering land constituted of a main-land and a sub-land is provided. The main-land is formed along one of longer sides of the slit. The sub-land is elongated from the main-land along a shorter side of the slit. The soldering land is not formed all around the slit so that the slit is not closed by solder when the circuit board is dip-soldered.

Abstract: An electronic component mounting method by which a surface-mount component and an IC can be efficiently and reliably mounted on a single substrate is provided. A high-temperature solder paste (4) is supplied to electrodes (2) for receiving surface-mount components (40), and the surface-mount components (40) are provisionally fixed on the electrodes (2) with the high-temperature solder paste (4). In addition, flux (5) is applied to an electrode (1) for receiving an IC (30a) that is provided with eutectic solder bumps (31) or on the eutectic solder bumps (31), and the IC (30a) is provisionally fixed on the electrode (1) with the flux (5). Then, a wiring substrate (10) is heated to a high temperature at which both the high-temperature solder and the eutectic solder melt, so that the surface-mount components (40) and the IC (30a) are reflow-soldered.

Abstract: A method for fabricating a printed circuit board includes the steps of: fabricating a printed circuit board having at least one collapsed portion; depositing a first solder resist in the collapsed portion; exposing the first solder resist-coated printed circuit board at a pressure lower than atmospheric pressure for a predetermined time; coating a second solder resist on the entire surface of the printed circuit board; and drying and hardening the first and the second solder resists. With this method, when a solder resist is coated, since an air space does not remain in a blind via hole, the reliability of the attachment between a printed circuit board and the solder resist layer is increased.

Abstract: A welding method for improving the durability and strength of fusion weld joints in metal structures; the method is especially beneficial for metal structures fabricated from nickel-titanium alloy (nitinol) and for medical devices.

Abstract: A method for joining a multiplicity of multi-alloy solder columns to an electronic substrate and the structure formed by such method are disclosed. In the method, a mold plate equipped with a multiplicity of cavities is first filled by an injection molded solder technique with a high temperature solder forming a multiplicity of solder columns. The mold plate is then sandwiched between an extraction plate and a transfer plate by utilizing a multiplicity of displacement means equipped in the extraction plate to displace the multiplicity of solder columns from the mold plate into a multiplicity of apertures equipped in the transfer plate. The multiplicity of cavities in the transfer plate each has a straight opening and a flared opening. The flared opening is then filled with a low temperature solder paste to encapsulate one end of the high temperature solder column.

Abstract: The invention relates to a method for forming a welded joint between abutting pieces of steel. The welded joint is produced by first forming a strength weld and then depositing additional weld metal on the toe of the strength weld to form a toughness weld. The fusion interface of the toughness weld forms a minimum angle with the direction of the maximum tensile load across the welded joint. The toughness weld toe is separated from the heat-affected zone of the strength weld to effectively prevent propagation of a crack initiated at the toughness weld toe into the heat-affected zone of the strength weld. The welded joint so produced is substantially resistant to failure by brittle fracture.

Abstract: Process for the selective formation of contact metallisations on terminal areas of a substrate, wherein the surface of the substrate is covered with a template in such a way that template openings forming deposit spaces are arranged above the terminal areas, and wherein the deposit spaces are filled with a solder material, and fusing of the solder material is effected with a view to forming the contact metallisations in the deposit spaces which are non-wettable at least in regions of contact with the solder material.

Abstract: A method of joining an end face of a first electric component to an end face of a second electric component includes applying a first metal layer to the end face of the first electric component to form a first metallized layer and applying a second metal layer to the end face of the second electric component to form a second metallized layer. A first fusible alloy layer is applied to the first metallized layer by melting a fusible alloy and propelling the melted fusible alloy onto the first metallized layer, and a second fusible alloy layer is applied to the second metallized layer by melting a fusible alloy and propelling the melted fusible alloy to the second metallized layer. The method further includes contacting the first fusible alloy layer to the second fusible alloy layer. Next, the end faces and fusible alloy layers are heated to melt the fusible alloy layers. After heating, the end faces and fusible alloy layers are cooled to form a bond between the end faces.

Abstract: A tip cap hole is loaded with a first composition comprising particles of a first alloy having a solidus temperature above the brazing temperature. The first composition is covered with a second composition comprising particles of a second alloy having a liquidus temperature below the brazing temperature. The second composition is heated to the brazing temperature to cause particles of the second alloy to melt to form a liquid of the second alloy which is carried into spaces between the particles of the first alloy by capillarity. The liquid of the second alloy is cooled to form a solid securely bonding the particles of the first alloy. By weight, the second alloy has no more than 1% B and from 3% to 11% Si. The first alloy has Cr and at least about 5% Al, at least about 0.5% Hf, no more than 0.5% Ti.

Abstract: A method for joining a multiplicity of multi-alloy solder columns to an electronic substrate and the structure formed by such method are disclosed. In the method, a mold plate equipped with a multiplicity of cavities is first filled by an injection molded solder technique with a high temperature solder forming a multiplicity of solder columns. The mold plate is then sandwiched between an extraction plate and a transfer plate by utilizing a multiplicity of displacement means equipped in the extraction plate to displace the multiplicity of solder columns from the mold plate into a multiplicity of apertures equipped in the transfer plate. The multiplicity of cavities in the transfer plate each has a straight opening and a flared opening. The flared opening is then filled with a low temperature solder paste to encapsulate one end of the high temperature solder column.

Abstract: A method of bonding together at least two long, metal alloy segments, of turbine components, such as turbine blade segments (18, 19, 20 and 21) by: putting a melting point depressant between the segments at bond planes (34) between contracting segments; forming a heated zone across the segments and a heated front (32); where melt pools (36) form in a molten zone (38) at the heated front which front (32), pools (36) and zone (38) continuously move and pass along the bond planes (34); where crystal re-growth (35) occurs along the bonding planes to form bonds (34) between the individual segments (18, 19, 20 and 21) behind the moving molten zone (38).

Abstract: In a method for automatic multi-layer welding of a joint formed by two joint surfaces according to which method the contour of the joint in a number of cross-sections is established by means of a sensor emitting signals representative of the contour of the current cross-section of the joint. After evaluation, said signals control the deposition of the weld beads by means of a continuously fed electrode which is directed towards a welding zone in the joint.

Abstract: So that the brazing of aluminium parts with the use of a flux can be made effectively without employment of a corrodible metallic muffle, furnace inner walls made of carbonaceous refractory sheets are utilized as a brazing space, and an inert atmosphere supplied into this space is protected from the air by furnace outer walls which are made of steel sheets to form a furnace shell and which are made hermetical against the air.

Abstract: A pair of soldering irons are fixed to a sliding plate at a predetermined interval. The soldering irons are integrally moved so as to reciprocate in a rectangular direction relative to a conveyor belt. One of the soldering irons is conveyed to a working position of the conveyor belt and the other of them is separated from the conveyor belt. While one of the soldering irons solders a circuit board, the other is cleaned. The circuit board has a slit into which a metal plate is inserted and soldered. For the slit, a soldering land constituted of a main-land and a sub-land is provided. The main-land is formed along one of longer sides of the slit. The sub-land is elongated from the main-land along a shorter side of the slit. The soldering land is not formed all around the slit so that the slit is not closed by solder when the circuit board is dip-soldered.

Abstract: A welding method for improving the durability and strength of fusion weld joints in metal structures; the method is especially beneficial for metal structures fabricated from nickel-titanium alloy (nitinol) and for medical devices.

Abstract: The invention relates to the welding of cast-iron castings.The process for the fusion welding of spheroidal-graphite cast-iron castings comprises the following steps:a) a preheat at a temperature of between 230.degree. and 300.degree. C. is carried out before buttering the zone of the casting to be welded;b) a heat treatment at a temperature of between 800.degree. and 920.degree. C. is applied to the buttering for a suitable period and .then a cooling cycle is carried out;c) again, a preheat of the buttering is carried out at a temperature of between 130.degree. and 200.degree. C. and followed by a finish weld.Application to the repair of cast-iron castings and to the joining of cast-iron castings together or to steel castings.

Abstract: A method, and product created thereby, by which low melting point solder suitable for reflow connection of components is formed on select contacts of a printed circuit board. The method is particularly suited to the fabrication of populated printed circuit board having fine pitch devices including flip-chip devices, connected on a board including conventional coarse pitch surface mounted components. The fine pitch contacts of the board are exposed through holes in a stencil characterized in its ability to withstand solder reflow temperatures, not be wettable by solder, and have a coefficient of thermal expansion relatively matching the printed circuit board. Low temperature solder paste is screen deposited into the stencil openings. With the stencil fixedly positioned on the board, the solder paste retained by the stencil pattern is reflowed to selectively form on the underlying contacts of the printed circuit board.

Abstract: An improved welding method is provided for repairing broken rotors. The welding method preferably employs a 2.25Cr-1.0Mo-0.3V-type filler metal, preferably deposited using a narrow groove welding technique. The broken pieces are aligned end to end. A narrow groove is formed to substantially remove the end surfaces. The groove is preheated, filled with the welding filler metal, and postheated, resulting in a strong, high temperature resistant, long lasting weld.

Abstract: A method of applying a welded overlay to the interior surface of curved hollow articles such as 90 degree elbows utilizing a submerged arc welding gun curved to follow the radius of the hollow article and comprised of an elongated cylindrical body (27) and a curved weld head (10), welding tip holder (24) and welding tip (28) and incorporating a flux conveying system (16), (18) and (20) and a plurality of air release slots (22) by which the flow of flux to the weld area is controlled. A first series of overlapping welds is applied longitudinally to the interior surface of the hollow article to cover 90 degrees of the surface therein. The article is rotated and a second series of overlapping welds are applied 180 degrees from the first series and again covering 90 degrees of the interior surface. A third series of overlapping welds are applied beginning at either of the end welds of the first series and covering 90 degrees of the interior surface.

Abstract: A method is disclosed for producing an electric deposition foil producing drum for producing an electrically deposited metallic foil having a high quality. An opening tip end portion (14) opened toward the inside is formed in an inner surface portion of a joint portion (13) of an outer skin (12) made from a planar material in the form of a cylinder. The opening end portion (14) is welded from inside, and subsequently, the welded portion (15) and a portion close to the welded portion are bulged outwardly. A layer is welded in a recess (17) formed by the bulging work while cooling the outer surface of the outer skin. Subsequently, the welded layer is peened under a hot or cold work. Subsequently, the peened portion (18) is annealed. It is possible to obtain further advantages by using a welding means which does not require a welding rod for the welding of the joint portion (13).

Abstract: Single crystal, nickel based superalloy turbine blades are formed by fusion welding together two matched blade halves. The matched blade halves are joined by an electrospark deposition process which deposits a weld filler metal along the matched faying surfaces. The deposited weld filler metal is preferably the same nickel based superalloy used to form the single crystal turbine blades. Total heat input to the base metal is minimal so that distortion and metallurgical structure changes of the base metal are virtually nonexistent.

Abstract: A soldering method of this invention has the steps of coating a plurality of lead terminals of an electronic component with connecting paste-like solders corresponding to lead terminals on conductive pads disposed on a substrate, holding the electronic component at the position separated from the corresponding paste-like solders at the lead terminals, and thereafter moving the substrate into a heating atmosphere furnace to melt the paste-like solder. In the melting step, the paste-like solders start melting when the temperatures of the pads arrive at the melting point of the solder and flow on the pads until contacting with the corresponding lead terminals. Thus, improper connection of the lead terminals to the pads due to smaller thermal capacity of the lead terminals than that of the substrate including the pads can be eliminated and productivity can be greatly improved.

Abstract: The present invention is directed to a method for soldering each of a plurality of members (40), arranged in one or more parallel rows, to a separate one of a plurality of metallized pads (42) on a substrate (10), each pad being contiguous with a corresponding member. The method is initiated by tilting the substrate so that one end of each row of members and the metallized pads contiguous therewith are at a higher elevation than the other end. A stream (80) of molten solder and a dripping stream (88) of flux droplets are directed onto the substrate into the regions where the members are contiguous with the metallized pads. Simultaneously, the substrate is displaced relative to the streams along a path (96) inclined with respect to the horizontal and parallel to the rows of members so that the members and the metallized pads are successively coated with solder and then flux.

Abstract: Mechanical means and methods for delivery of solder preforms arranged in generally rectilinear patterns and oriented so that the ends of the solder preforms may join two planar surfaces upon the application of heat are disclosed. Several embodiments facilitate the delivery of solder preforms in the forms of posts, clips and rings.

Abstract: Segments of a clad pressure vessel are welded together along seams at which the cladding is removed to expose a steel backing, so that initially a groove opens out of the cladding toward the interior of the vessel at each seam. Batten strips cover the grooves, and each of those strips has a depressed center portion which fits into the groove for that strip to center the strip along its groove. The batten strip also has flanges which extend outwardly from the depressed portion to overlie the cladding, to which they are welded along their edges. Cover plates are welded over the ends of batten strips. Thus, the cladding, the batten strips and the cover plates totally isolate the steel backing of the pressure vessel from the interior of the vessel, so that the contents of the vessel will not corrode the backing.

Abstract: A method for performing multi-layer welding using a welding robot, in which welding on the second and subsequent layers is carried out by backwardly displacing the position of a torch tip by a preset value.

Abstract: A method for soldering aluminum or aluminum alloys is disclosed, together with an alloy useful in the method. The method includes heating, for example by using a torch, at least one aluminum piece to a temperature within the range of 90-150 degrees celsius, cleaning at least one heated surface thereof, for example by wire brushing, further heating the cleaned piece to a temperature within the range of 350-490 degrees celsius, and applying, for example by rub soldering, to the cleaned and further-heated piece a quantity sufficient to enable subsequent soldering, as required, of a tin/lead/zinc alloy consisting essentially of, by weight, from 1.7 to 2.2 percent aluminum, from 0.01 to 0.02 percent magnesium, from 45.9 to 50.4 percent zinc, from 14.2 to 34 percent tin, and from 16.6 to 36.7 percent lead.

Abstract: A butt welded tubular structure composed of tubular members of austenite stainless steel including a restraining member providing a cover to the entire outer circumferential surfaces of a welded joint and heat affected zones of the tubular members, the restraining member being formed of a metal or alloy of lower stress corrosion cracking sensitivity than the material of the tubular members and joined at the entire surfaces of opposite end portions thereof to the tubular members by welding, although the restraining member is not joined to the tubular members at portions of the restraining member corresponding to the welded joint and heat affected zones of the tubular members.

Abstract: A method comprises feeding two or more, if necessary, alloying materials and simultaneously changing the ratio thereof. The ratio of the alloying materials is changed at the moment of transition from one section to the other one having different composition, the ratio being changed to such extent that the length of the transition portion is as small as possible. The time of transition is determined depending on the weld pool volume, rate of surfacing, cross section of the layer being built up, amount of the alloying elements both the required and the real one. Determining the time of transition for carrying out the method of the invention is disclosed in term of a preferred embodiment. An apparatus for carrying out the method of the invention is characterized in that it includes an adder-differentiator link, a voltage limiter, a switching device and an aperiodical link. The aperiodical link is a simulator of the weld pool.

Abstract: An apparatus for multi-bead welding of two rotating workpieces comprises a flat filler wire holder which can be introduced into the gap between the workpieces and which is periodically pivoted forth and back at substantially constant angular velocity between the two sides of the gap. The pivoting is effected by a motor which is started when a cam rotating in synchronism with the workpieces actuates a stationary signal generator. The cam is provided on a cam disc which is driven through a friction coupling and which, on each revolution, is arrested by a pawl during a period determined by an adjustable timer. The timer is started when the cam actuates a stationary signal generator mounted shortly in advance of the pawl, and after the expiry of the period of the timer the pawl is retracted so that the rotation of the cam disc can continue. The pawl is again advanced to operative position when the cam actuates the first mentioned signal generator.

Abstract: A method for preventing the development of cracks below seams during the plating and welding of material by employing a heat source for producing local heating of the regions of the material adjacent the welding zone.

Abstract: A ferrous or like metal attachment or coupling, such as a heavy round lug, includes a generally cylindrical body having a beveled base and a divider land or keel extends diametrically across the base and projects downwardly therefrom and divides the beveled base into two generally coequal component weld surface areas on opposite sides. The body of the metal coupling is positioned at a desired and preselected point on the external surface of a metal pipe or tube whereupon the metal coupling is preliminarily welded to join the divider land or keel to the external surface of the metal pipe or tube.

Abstract: A method and apparatus for repairing a radiator having a header and tubes that extend into the header which may develop leaks. The apparatus is made up of a U-shaped rod or wire that is slipped over the tube adjacent the header and the U-shaped rod or wire is soldered in place around the tube.

Abstract: The stress corrosion tendency of a welded pipe in service in a nuclear reactor water line is reduced by applying to the outside of the pipe a secondary weld bridging the primary weld of the joint beyond the axial extremities of the primary weld heat affected zone and particularly that part of the zone at the inner surface of the pipe.

Abstract: A curved section is provided for connecting in a conduit through which passes a fluid stream having solid material entrained therein. A plurality of wear strips are attached to the inside wall of the curved section. They are positioned for the solid material to impinge thereon as the fluid stream changes its direction of flow as it passes through the curved section. The wear strips are elongated members of wear resistant material positioned side-by-side along the inside wall against which the solid material impinges. The abutting sides of adjacent wear strips are beveled so that the outer edges of one adjacent strip extends over the inner edge of the other adjacent strip to provide a continuous surface of wear resistant material in the path of the entrained solid material.