The present application discloses a reflow oven and the operation method thereof. The reflow oven can operate in air mode and inert gas mode. The reflow oven comprises a heating zone, a blocked exhaust zone and a cooling zone. The reflow oven further comprises a first pipeline, a second pipeline and a third pipeline. When the reflow oven operates in air mode, external clean air is delivered to the heating zone and is discharged from the heating zone and the blocked exhaust zone. When the reflow oven operates in inert gas mode, an inert gas is delivered from the blocked exhaust zone to the heating zone and is discharged from the heating zone. Satisfying the accurate temperature profiling necessary for reflow processing in the operation atmosphere of air or an inert gas, the reflow oven in the present application can effectively discharge volatile pollutants to reduce the number of follow-up services and maintenances. In addition, the reflow oven in the present application can save the expensive inert gas.

A method for producing a joined structure according to the present invention includes: a reflow step of heating a first member and a solder material while keeping them in contact with each other in a reflow chamber to melt a solder alloy constituting the solder material, the reflow step including: a first reflow step of melting the solder alloy with an atmosphere in the reflow chamber reduced to a first pressure P.sub.1 lower than the atmospheric pressure; and a second reflow step of, after the first reflow step, melting the solder alloy with the atmosphere in the reflow chamber reduced to a second pressure P.sub.2 lower than the first pressure P.sub.1.

A method for repairing a through-hole includes inserting a repair coil, comprising a tightly-wound repair strip, into a through-hole and inserting a heating element into the repair coil. Passing an electrical current through the heating element liquefies a bonding material disposed on the repair coil and the repair coil expands within the through-hole. Subsequently solidifying the bonding material bonds the repair coil to the through-hole. A repair assembly comprises a repair coil inserted into a through-hole and a heating element inserted into the repair coil. The repair coil comprises a tightly-wound repair strip. The heating element comprises a segment of a heating wire enclosed within an insulating material. Passing an electric current through the segment of the heating wire liquefies bonding material disposed on the repair coil and the repair coil expands within the through-hole. The liquified bonding material solidifies to bond the repair coil to the through-hole.

A method for repairing a through-hole includes inserting a repair coil, comprising a tightly-wound repair strip, into a through-hole and inserting a heating element into the repair coil. Passing an electrical current through the heating element liquefies a bonding material disposed on the repair coil and the repair coil expands within the through-hole. Subsequently solidifying the bonding material bonds the repair coil to the through-hole. A repair assembly comprises a repair coil inserted into a through-hole and a heating element inserted into the repair coil. The repair coil comprises a tightly-wound repair strip. The heating element comprises a segment of a heating wire enclosed within an insulating material. Passing an electric current through the segment of the heating wire liquefies bonding material disposed on the repair coil and the repair coil expands within the through-hole. The liquified bonding material solidifies to bond the repair coil to the through-hole.

A method for producing a ceramic circuit board including a ceramic substrate and a metal circuit formed on the ceramic substrate. The disclosed method includes a step of forming the first metal layer in contact with the ceramic substrate by spraying a first metal powder containing at least either of aluminum particles or aluminum alloy particles together with an inert gas onto a surface of a ceramic substrate from a nozzle, in which the first metal powder is heated to from 10 C. to 270 C. and then ejected from the nozzle 10 and a gauge pressure of the inert gas at an inlet of the nozzle 10 is from 1.5 to 5.0 MPa, a step of subjecting the first metal layer to a heat treatment in an inert gas atmosphere, and the like.

An electroconductive paste comprises high melting point metal particles having a melting point that exceeds the firing temperature; molten metal particles containing a metal or an alloy that melts at the firing temperature, for which the melting point is 700 C. or less; active metal particles containing an active metal; and an organic vehicle.

The purpose of the present invention is to provide an electronic component in which a copper electrode and an inorganic substrate exhibit strong adhesion to each other. A method for producing an electronic component according to the present invention comprises: an application step wherein a paste is applied onto an inorganic substrate, which paste contains copper particles, copper oxide particles and/or nickel oxide particles, and inorganic oxide particles having a softening point; a sintering step wherein a sintered body which contains at least copper is formed by means of heating in an inert gas atmosphere at a temperature that is less than the softening point of the inorganic oxide particles but not less than the sintering temperature of the copper particles; and a softening step wherein heating is carried out in an inert gas atmosphere at a temperature that is not less than the softening point of the inorganic oxide particles.

A method for producing a ceramic circuit board including a ceramic substrate and a metal layer formed on the ceramic substrate, includes a step of forming the metal layer on the ceramic substrate by spraying a metal powder after accelerating the metal powder to a velocity of from 250 to 1050 m/s as well as heating the metal powder to from 10 C. to 270 C. and a step of subjecting the ceramic substrate and the metal layer to a heat treatment in an inert gas atmosphere.

A method for manufacturing a printed circuit board, comprising in order steps (i) providing a non-conductive substrate having on a surface copper circuitry with a copper surface, wherein said surface is chemically treated by (a) oxidation and subsequent reduction reaction and/or (b) organic compound attached to said surface, a permanent, non-conductive, not fully polymerized cover layer covering at least partially said surface, (ii) thermally treating the substrate with the cover layer at temperature from 140 C. to 250 C. in atmosphere containing molecular oxygen at 100000 ppm or less, based on the total volume of the atmosphere, wherein a substrate with a permanent, non-conductive cover layer is obtained, with the provisos that (ii) is after (i) but before any metal or metal alloy is deposited onto the cover layer, and that in (ii) the cover layer is fully polymerized in one thermal treating step, if the cover layer is a solder mask.

A method for soldering an electronic component to a circuit board involves jetting liquefied solder. A laser beam melts a solid solder ball to produce a liquefied solder ball before the ball is jetted. The liquefied solder ball is jetted towards a through hole in the circuit board such that a portion of the liquefied solder ball flows into an annular gap between a pin and sides of the through hole. The pin is attached to the electronic component and passes through the through hole. As the liquefied solder ball is jetted towards the through hole, the laser beam is directed at the ball so as to keep it liquefied. How much of the solder ball remains outside the through hole after liquefied solder has flowed into the annular gap is determined. The filling degree of the annular gap is determined based on how much solder remains outside the hole.