Abstract: A structure and a formation method of a package structure are provided. The method includes forming one or more solder elements over a substrate. The one or more solder elements surround a region of the substrate. The method also includes disposing a semiconductor die structure over the region of the substrate. The method further includes dispensing a polymer-containing liquid onto the region of the substrate. The one or more solder elements confine the polymer-containing liquid to being substantially inside the region. In addition, the method includes curing the polymer-containing liquid to form an underfill material.

Abstract: Provided is a method for removing an electronic component from a printed wiring board. The method comprises applying an embrittlement agent to a lead of an electronic component that is soldered to the printed wiring board. The electronic component is removed from the printed wiring board by breaking the embrittled lead.

Abstract: Systems and methods for providing a soldered interface between a circuit board and a connector pin. The methods comprise: using a jet paste dispenser to apply first solder into a plated contact cavity formed in the circuit board; using a stencil screen printer to apply second solder (a) over the plated contact cavity which was at least partially filled with the first solder by the jet paste dispenser and (b) over at least a portion of a pad surrounding the plated contact cavity; inserting the connector pin in the plated contact cavity such that the connector pin passes through the second solder and extends at least partially through the first solder; and performing a reflow process to heat the first and second solder so as to create a solder joint between the circuit board and the connector pin.

Abstract: Implementations of semiconductor packages may include a first die including a plurality of contact pads, a second die including a plurality of contact pads, a plurality of solder interconnects bonding the plurality of contact pads of the first die to the plurality of contact pads of the second die, and a plurality of magnetic particles each coated in an oxide included in each of the plurality of solder interconnects.

Abstract: A semiconductor device includes a package substrate, a semiconductor chip on a first region of the package substrate, and a solder bump on a second region of the package substrate. The solder bump includes a core portion and a peripheral portion encapsulating the core portion. The peripheral portion includes a first segment with a first melting point and a second segment with a second melting point that is less than the first melting point.

Abstract: Provided is a manufacturing method of a double-sided printed circuit board. In the method, a first conductive circuit pattern configuring a circuit is formed on an upper side of an insulation layer, and a second conductive circuit pattern configuring a circuit is formed on a lower side of the insulation layer. A through hole vertically passing through the insulation layer is formed, and a conductive material is formed on an inner circumferential surface of the through hole such that the first circuit pattern and the second circuit pattern are electrically connected by the through hole.

Abstract: Embodiments of the present disclosure are directed to integrated circuit (IC) package assemblies with magnetic contacts, as well as corresponding fabrication methods and systems incorporating such magnetic contacts. A first IC substrate may have a first magnet coupled with a first electrical routing feature. A second IC substrate may have a second magnet coupled with a second electrical routing feature. The magnets may be embedded in the IC substrates and/or electrical routing features. The magnets may generate a magnetic field that extends across a gap between the first and second electrical routing features. Electrically conductive magnetic particles may be applied to one or both of the IC substrates to form a magnetic interconnect structure that extends across the gap. In some embodiments, magnetic contacts may be demagnetized by heating the magnets to a corresponding partial demagnetization temperature (PDT) or Curie temperature. Other embodiments may be described and/or claimed.

Abstract: In a reflow soldering apparatus, air heated by heaters is blown by fans onto a printed circuit board. Temperature controllers that control temperature of the heaters supply operation amount thereof to a calculation unit that calculates consumed electric energy of soldering apparatus. Inverters that control revolution of fans supply a value of current to the calculation unit. A control unit supplies a coefficient of the consumed electric energy to the calculation unit. The calculation unit calculates a total amount of consumed electric energy of the reflow soldering apparatus based on the operation amount, value of current and coefficient of the consumed electric energy thus obtained. A display unit displays on an operation screen the total amount of consumed electric energy of the reflow soldering apparatus, which has been calculated by the calculation unit.

Abstract: The present invention relates to a method for providing a braze alloy layered product comprising the following steps: —applying at least one silicon source and at least one boron source on at least a part of a surface of a substrate, wherein the at least one boron source and the at least one silicon source are oxygen free except for inevitable amounts of contaminating oxygen, and wherein the substrate comprises a parent material having a solidus temperature above 1100° C.; —heating the substrate having the applied boron source and the applied silicon source to a temperature lower than the solidus temperature of the parent material of the substrate; and cooling the substrate having the applied boron source and the applied silicon source, and obtaining the braze alloy layered product. The present invention relates further to a braze alloy layered product, a method for providing a brazed product, a method for providing a coated product, and uses of the braze alloy layered product.

Abstract: Disclosed is a heat exchanger comprising a boiling passage and cooling passage defined by opposite sides of metal walls. Layers of brazing material between the metal walls and a spacer member bond components of the heat exchanger together. It has been found that good quality brazed joints can be made by modifying the brazing thermal cycle to first employing a temperature of about 500° C. for an extended period of time and then elevating the temperature to about 590° to 600° C.

Abstract: Provided herein is a method for securely fixing a connecting element on a metal workpiece by welding involving the formation of locally confined weld points that permits the friction-increasing, play-free, reversible connection of joined workpieces for applications in assembly and transportation. The connecting element includes a metal foil having hard material particles fixed on the joining surfaces by a metallic binding layer. Similarly, a component having a metal workpiece and the connecting element, which is suitable for the connection of workpieces to be joined in machine, plant, and motor vehicle construction, is also provided.

Abstract: A solder joint may be used to attach components of an organic vapor jet printing device together with a fluid-tight seal that is capable of performance at high temperatures. The solder joint includes one or more metals that are deposited over opposing component surfaces, such as an inlet side of a nozzle plate and/or an outlet side of a mounting plate. The components are pressed together to form the solder joint. Two or more of the deposited metals may be capable of together forming a eutectic alloy, and the solder joint may be formed by heating the deposited metals to a temperature above the melting point of the eutectic alloy. A diffusion barrier layer and an adhesion layer may be included between the solder joint and each of the components.

Abstract: The present disclosure relates to the field of fabricating microelectronic packages, wherein magnetic particles distributed within a solder paste may be used to form a magnetic intermetallic compound interconnect. The intermetallic compound interconnect may be exposed to a magnetic field, which can heat a solder material to a reflow temperature for attachment of microelectronic components comprising the microelectronic packages.

Abstract: An electrode structure 100 on which a solder bump is placed includes an electrode pattern 50 made of an electrode-constituting material selected from the group consisting of Cu, Al, Cr, and Ti, a Ni layer 52 formed on a part of the electrode pattern 50, a Pd layer 54 formed on at least a part of a region other than the part of the electrode pattern 50, and an Au layer 56 formed on the Ni layer 52 and the Pd layer 54.

Abstract: A system and method of restoring material properties is disclosed. A subject material may have one or more of its material properties restored by contacting a packed bed of a reactive material contained within a container with the subject material in which material properties are desired to be restored. The packed bed and the subject material may be heated to restore the material properties. The packed bed may be formed from boron, silicon or other appropriate materials. An inert atmosphere system may have an argon injection system or a helium injection system in communication with the container. A deoxidizing system may be in communication with the container for creating a vacuum within the container or injecting hydrogen into the container.

Abstract: The invention relates to a starter material for a sintering compound, said starter material comprising first particles of at least one metal having a first coating which is applied to the first particles and consists of an organic material, and second particles which contain an organic metal compound and/or a precious metal oxide, the organic metal compound and/or the precious metal oxide being converted during heat treatment of the starter material into the fundamental elemental metal and/or precious metal. The invention is characterized in that the second particles have a core of at least one metal and a second coating which is applied to the core and contains the organic metal compound and/or precious metal oxide. Furthermore, the first coating contains a reducing agent by means of which the organic metal compound and/or the precious metal oxide is/are reduced to the elemental metal and/or precious metal at a temperature below the sintering temperature of the elemental metal and/or precious metal.

Abstract: Provided are a method for producing a clad material, and a clad material which can prevent a brazing filler metal layer from having a higher melting point so as to prevent the strength degradation and thermal deformation of a metal material, which can reduce production costs, which can reduce in thickness the layer to prevent sagging of the brazing filler metal upon brazing and which can improve press formability. A powder press-fixing machine is used to press-fix metal powder to surfaces of a base material uncoiled from a coil by an uncoiler. In order to provide a required composition of brazing filler metal, at least two kinds of metal powder is mixed, the mixed powder being press-fixed to the base material to form the brazing filler metal layer, the brazing filler metal constituting the layer having the composition such that copper is added with at least phosphor to lower a melting point of the same relative to that of copper, thus producing the clad material.

Abstract: A method for repairing a gas turbine engine component includes applying a braze slurry to a first portion of the component, applying a pre-sintered preform to a second portion of the component that is different than the first portion, and brazing the component.

Abstract: Provided is a composite nanometal paste, whose layer, when sintered in an inert gas under no load, gives a metal layer that is equal or superior in electrical conductivity and thermal conductivity to conventional lead-rich solders. The composite nanometal paste contains, as metal components, composite metal nanoparticles comprising metal cores with an average particle diameter of d (nm) and an organic coating layer formed around the circumference, and metal filler particles having an average particle diameter of D (nm), and satisfies the first relation d<D and the second relation d<100 (nm).

Abstract: Provided is a composite nanometal paste which, when a layer of the paste interposed between upper and lower bodies is sintered in an inert gas under no load until the layer turns to a metal layer, attains a shear bond strength between the upper and lower bodies of 10 MPa or higher. The composite nanometal paste contains, as metallic components, composite metallic nanoparticles comprising metal cores with an average particle diameter of X (nm) and an organic coating layer formed around the circumference, metallic nanofiller particles having an average particle diameter of d (nm), and metallic filler particles having an average particle diameter of D (nm), and satisfies the first relation X<d<D and the second relation X<d<100 (nm).

Abstract: A sintering material having metallic structural particles which are provided with an organic coating. Non-organically coated, metallic and/or ceramic auxiliary particles are provided that do not outgas during the sintering process. A sintered bond, as well as a method for producing a sintered bond.

Abstract: A mixed mother alloy is prepared from a solder mixture comprising a pyrolyzable flux and high melting point metal particles, the mixed mother alloy is charged into a large amount of molten solder and stirred, and a billet is prepared. The billet can then be extruded, rolled, and punched to form a pellet or a washer, for example.

Abstract: Embodiments in the present invention provide a system and method of joining structural members. This method involves aligning the first structural member to a metallic substrate when the first structural member has at least one tapered hole or cavity. A metallic or other like material suitable to cold spraying technology is deposited into the tapered cavity to form a shaped or tapered fastener bonded to the metallic substrate. The shape of the fastener secures the first structural member to the metallic substrate. Additionally, a protective insert may be placed within the shaped or tapered cavity to protect the first structural member during hoe cold spraying deposition when the first structural member is a composite material or other like material susceptible to erosion during the cold spraying technique.

Abstract: A weld process cuitable for repairing precipitation-strengthened superalloys, and particularly gamma prime-strengthened nickel-based superalloys. The process entails forming a weldment in a cavity present in a surface of an article formed of a precipitation-strengthened superalloy. The cavity has a root region and a cap region between the root region and the surface of the article. A solid body formed of a superalloy composition is placed in the root region of the cavity so as to occupy a first portion but not a second portion of the root region. A first filler material formed of a solid solution-strengthened superalloy is then weld-deposited in the second portion of the root region. Subsequently, a second filler material formed of a precipitation-strengthened superalloy is weld-deposited in the cap region of the cavity.

Abstract: A method of bonding a stainless steel part to a titanium part by heating a component assembly comprised of the titanium part, the stainless steel part, and a compact titanium-nickel filler material placed between the two parts and heated at a temperature that is less than the melting point of either the stainless steel part or the titanium part. The compact filler material is made of particles, preferably spheres, of discrete layers of nickel and titanium metal that react with each other and with the stainless and titanium parts to form a strong assembly when thermally processed. The component assembly is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a hermetic and strong bond between the stainless steel part and the titanium part.

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: The invention is a method of bonding a ceramic part (6) to a metal part (4) by heating a component assembly (2) comprised of the metal part (4), the ceramic part (6), and a thin laminated interlayer material (8) placed between the two parts and heated at a temperature that is greater than the temperature of the eutectic formed within the laminated interlayer material (8) or between the metal part (4) and the laminated interlayer material (8), but that is less than the melting point of the ceramic part (6) or of the metal part (4). The component assembly (2) is held in intimate contact at temperature in a non-reactive atmosphere for a sufficient time to develop a strong bond between the ceramic part (6) and the metal part (4). The compact interlayer material (8?) may be further comprised of two or more sets of metal alloy spheres (16, 16?) each having distinct compositions.

Abstract: Solder pastes for providing high elasticity, low rigidity solder joints are disclosed. The solder pastes may be used between two parts having large mismatches in their coefficients of thermal expansion and/or when there is a high likelihood of mechanical deformity when the two parts are soldered together. In one particular exemplary embodiment, a solder paste may be realized as a composition comprising a solder powder and high melting temperature particles with a flux, wherein the ratio between solder powder and high melting temperature particles may be between 2:1 and 1:10.

Abstract: An electronic package (10) is provided which includes a circuit board (12) having a substrate (14) and circuitry (16) and a surface mount device (22) having a contact terminal (24). A mounting pad (28) is formed on the circuit board (12). The electronic package (10) also includes a solder joint (30) connecting the contact terminal (24) of the surface mount device (22) to the mounting pad (28) on the circuit board (12). The solder joint (30) includes a reflowable solder and a plurality of stand-off members (32 or 42). The stand-off members (32 or 42) provide a separation distance (H) between the circuit board (12) and surface mount device (22) in the range of about 0.01 mm to 0.10 mm.

Abstract: A method for utilizing superplastic deformation with or without a novel joint compound that leads to the joining of advanced ceramic materials, intermetallics, and cermets. A joint formed by this approach is as strong as or stronger than the materials joined. The method does not require elaborate surface preparation or application techniques.

Abstract: A polymer masking flux for fabricating external contacts on semiconductor components includes a polymer resin, a fluxing agent and a curing agent. The flux is configured to clean contact pads for the external contacts, and to hold the external contacts on the contact pads during a reflow bonding process. The flux is also configured to cure or polymerize, to form donut shaped polymer support members for the external contacts. In addition, the flux is configured to mask conductive traces in electrical communication with the contact pads, and to electrically insulate the external contacts from the conductive traces. The external contacts can be pre-formed solder balls, or deposited solder bumps. In the case of solder bumps, the flux can include solder particles configured to coalesce into the solder bumps.

Abstract: In the multilayer inductor, the substrate thereof is composed of a constituent belonging to spinel ferrite, and is furnished with internal conductors of a main constituent being silver at the interior of the substrate. The internal conductors are drawn outside of the substrate, and the drawn portions are provided with external electrodes. The internal conductors contain manganese and bismuth, and the manganese and bismuth contents at an interface between the internal conductors and the substrate are more than those of other ranges. MnO2 of 0.02 to 0.1 wt % and Bi2O3 of 0.5 to 1.2 wt % are added to a paste of the main constituent being silver to be used to the internal conductors, and the paste is baked together with spinel ferrite material.

Abstract: The present invention involves a composite pallet for a substrate of a printed circuit board for a vector transient reflow process. The composite pallet includes a heat conductive layer for heat sinking means from the substrate and a heat insulative layer adjacent the conductive layer to shield the substrate from heat and to absorb heat from the heat conductive layer. The heat conductive layer has first and second opposite surfaces. The first surface is configured to receive the substrate disposed thereon to diffuse heat from the substrate during the vector transient reflow process. The heat insulative layer is disposed adjacent the second surface.

Abstract: A method for the manufacturing or repair of a superalloy gas turbine component including a liquid phase diffusion bonding process wherein the brazing heat treatment used for the diffusion bonding of a powder material to the component is accomplished by a heat cycle that is performed on the component for another purpose. A manufacturing solution heat treatment, a pre-weld heat treatment, a post-weld heat treatment, or a rejuvenating heat treatment may be used as the brazing heat treatment. The composition of the powder material is selected so that a desired set of material properties is achieved when the powder material is subjected to the dual-purpose heat cycle. In one embodiment, a 50/50 mixture of AM775 and IN939 powder is diffusion brazed to an IN939 superalloy component using a heat treatment which also functions as the post-casting solution heat treatment for the IN939 component.

Abstract: A directionally solidified nickel-base superalloy article has a defect therein extending parallel to the solidification direction. The article is repaired by removing any foreign matter present in the defect, and then heating the article to a repair temperature of from about 60 to about 98 percent of the solidus temperature of the base material in a chamber containing a protective gas that inhibits oxidation of the base material. The defect is filled with a filler metal while maintaining the article at the repair temperature. The filling is accomplished by providing a source of the filler metal of substantially the same composition as the base material of the directionally solidified article, and melting the filler metal into the defect progressively while moving the source of the filler metal relative to the article in a direction parallel to the solidification direction.

Abstract: A modified aperture shape for screen printing eliminates insufficient solder without increasing the number of solder bridges. The shape is narrow in the area where the component lead will touch and wide or overprinted in the area where the lead does not touch. To further increase solder volume the length of the aperture can also be overprinted. The overprinted areas provide greater solder volume, while the narrow area where the lead will touch prevents solder bridging.

Abstract: A cleaning apparatus for cleaning solder paste off the bottom side of a printed circuit board stencil includes a container of cleaning solution therein and a blade holder that is movable between a wiping position and the container of cleaning solution. A wiping blade is mounted in the blade holder. The blade holder, with the blade mounted thereon, is reciprocated back and forth when in communication with a stencil to be cleaned. The blade is moved from the wiping position in communication with the stencil into the cleaning solution in the container. A pneumatic piston and rotary actuator provides controlled movement of the wiping blade. The wiping blade may be vibrated during wiping to improve removal of solder paste from the stencil and the cleaning solution may be ultrasonically vibrated to improve removal of solder paste from the wiping blade. The wiping blade may also be pulsed into a sponge to remove excess cleaning solution prior to the next cleaning cycle.

Abstract: An article includes a substrate and an adhesion layer overlying the substrate. The adhesion layer includes a first phase including particles, and a second phase including braze alloy that bonds the particles to the substrate. The article further includes a ceramic layer overlying the adhesion layer. In one embodiment, the ceramic layer is a thermal barrier coating (TBC), formed of stabilized zirconia (ZrO2).

Abstract: A method of manufacturing a ceramic capacitor relates to a ceramic capacitor having metal plate terminals that absorb thermal stress and mechanical stress caused by flexure of the substrate. A ceramic capacitor element is provided with terminal electrodes at the two side end surfaces facing opposite each other. The metal plate terminals are each connected to one of the terminal electrodes at one end thereof, are each provided with a folded portion in a middle area and a terminal portion to be connected to the outside toward the other end from the folded portion.

Abstract: A directionally solidified nickel-base superalloy article has a defect therein extending parallel to the solidification direction. The article is repaired by removing any foreign matter present in the defect, and then heating the article to a repair temperature of from about 60 to about 98 percent of the solidus temperature of the base material in a chamber containing a protective gas that inhibits oxidation of the base material. The defect is filled with a filler metal while maintaining the article at the repair temperature. The filling is accomplished by providing a source of the filler metal of substantially the same composition as the base material of the directionally solidified article, and melting the filler metal into the defect progressively while moving the source of the filler metal relative to the article in a direction parallel to the solidification direction.

Abstract: A method for applying a brazing medium to a configuration, which includes a honeycomb body and a jacket pipe, is described. First, the honeycomb body is formed by stacking and/or winding of sheet metal layers. At least some of which are structured sheet metal layers, such that the honeycomb body has channels for conducting a fluid flow. The honeycomb body is introduced into the jacket pipe. At least one end face of the honeycomb body is brought into contact with a roller having an adhesive medium disposed thereon, and the roller is mounted rotatably about a roller axle. The configuration and the roller are moved relative to one another such that the roller deposits the adhesive medium onto the honeycomb body. Subsequently, a brazing medium is introduced at least into the honeycomb 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.

Abstract: A method of forming cylindrical bumps on a substrate for integrated circuits includes the steps of: forming copper circuits on a board of a substrate by means of electroplating; covering said board with a screening material; forming openings in said screening material to align with copper circuits on said board, filling pure copper or high melting point metal into said openings by electroplating to form cylindrical projections; forming a layer of solder alloy on an upper end of each of said cylindrical projections to be even with an upper surface of said screening material, and removing said screening material to leave the cylindrical bumps, whereby the engagement operation between the die and the substrate can be facilitated and the manufacture of the die can be easier.

Abstract: A method for forming a metallic contact and manufacturing a product having an electronic component 101 and a printed circuit board 100 (PCB) includes dispensing a slurry solder paste mixture 104 including a metallic powder 105 and an acidic fluid 106, placing electronic component 101 over solder paste dispensed over a surface area of PCB 100, and applying pressure on at least a section of electronic component 101 such that at least a portion of slurry solder paste mixture 104 dispensed on the surface area and in contact with the section of electronic component 101 consolidates into at least one of an inter-metallic compound of hardened solder and a hardened alloy of solder forming the metallic contact between electronic component 101 and said PCB 100.

Abstract: A composite material is produced by a method where an adhesive composition which comprises a particulate material that reduces thermal stress and a brazing material containing a noble metal element as a base, wherein the adhesive composition can bond two or more kinds of different members to form a composite member with sufficient bond strength to avoid causing damages, such as cracks that occur on the side of the member that is weak against thermal stress, and also by a method to produce a composite member comprised of two or more kinds of different members, in which either the adhesive composition is used or the bonding portion of the different members is filled with the particulate material that reduces thermal stress, and then a molten brazing material is poured there into, and cooled to bond the members.

Abstract: To improve the resistance of a solder to strains, especial thermal strains, superelastic particles are incorporated into the solder in a proportion by volume of 10 to 30% approximately. So that this incorporation can be done, the particles are coated with a metal, for example copper, that is wettable by the solder.

Abstract: A method of manufacturing a lead-free electrical solder paste having primary solder powder and an additive metal powder component that does not melt during the soldering process. Metal powders may be either elemental metal or a metal alloy. The primary powder is the same as is used in conventional solder paste. The additive powder has a melting point substantially higher than the melting point of the primary powder. The primary powder comprises between 80-99% Sn and 1-20% Ag. The additive powder metal is selected from the metal group comprising Sn, Ni, Cu, Ag, and Bi and mixtures thereof.

Abstract: Soldering methods and compositions are disclosed to provide electrical connections between surfaces with reduced likelihood of short circuits or solder-starved joints. Two component solder compositions are employed to preferably form “metallic foam” joints upon heating. In one embodiment, bimetallic particles are disclosed which fuse together rapidly reducing the likelihood of reflow-related solder joint faults. The methods and compositions of the present invention can also reduce the potential for thermal fatigue and other solder joint failures in electronic devices following fabrication because the porous solder joints relieve plastic constraints and lower the average tensile joint stress. In one preferred embodiment, solder compositions are employed which are composed of particles of a first metal coated with a second metal. Alternatively, the compositions can include particles of a first metal surrounded by a salt solution or suspension of a second metal.

Abstract: Electrical connection device for forming electrical connection between a first portion and a second portion of a semiconductor device. The first portion is set near or in contact with the second portion. The first and second portions are electrically connected by spraying fine metal particles of gold, nickel or copper in a carrier gas of helium, argon, hydrogen or nitgrogen on the first and second portions to form a metal bump. Prior to spraying the fine metal particles to form the metal bump, hard particles of titanium, copper, hafnium, zirconium or vanadium may be sprayed on the first and second portions to remove contamination layers.

Abstract: A method of integrated circuit assembly before encapsulation including at least one step of soldering, under mechanical pressure, a first element on a second element, including temporarily maintaining a predetermined spacing, at least partially without solder paste, between the surfaces to be assembled of the first and second elements.