Abstract: There is provided a flow soldering process for mounting an electronic component onto a board by a solder material, which process is appropriate for using a lead-free solder material as the solder material. In the flow soldering process, thermal efficiency of flow soldering is improved in preheating step and/or solder material supplying step thereof. In one aspect of the present invention, a heating cover is located above a preheater, and the flow soldering is conducted while the board passes between the heating cover and the preheater. In another aspect of the present invention, a gap between a preheater and a solder bath is 20 to 60 mm. In yet another aspect of the present invention, a distance between a primary wave and a secondary wave is not larger than 60 mm.

Abstract: There is provided a method which can conveniently estimate a quality of a lead-free solder material used for a flow soldering process. In the present invention, a differential thermal analysis curve of a sample of the lead-free solder material is obtained by utilizing a differential thermal analysis method, and thereby a quality of the lead-free solder material used for a flow soldering process is estimated based on the obtained differential thermal analysis curve.

Abstract: There is provided a flow soldering process for mounting an electronic component onto a board by a solder material, which process is appropriate for using a lead-free solder material as the solder material.

Abstract: It is realized that a solder material is sufficiently supplied to a through hole formed through a board by a spraying mode flux applying method in a flow soldering process for mounting an electronic component onto the board by means of a solder material.

Abstract: There is provided a method which can conveniently estimate a quality of a lead-free solder material used for a flow soldering process.

Abstract: An injection molding valve nozzle comprises a nozzle head with a gate dividing a flow passage into two sections, a spool slidably attached to the gate and including axial grooves in its outer surface and a spring for urging the spool rearward. The valve nozzle is so arranged that the gate is closed by the spool because the grooves do not reach the gate upon lower pressure of resins below a certain level, but that the spool may slide forward to extend the grooves over the gate, communicating a front passage with a rear passage upon higher resin pressure above a certain level and that when the pressure differential between the front and rear passages decreases or the resin pressure descends below a certain level, the spool slides rearward by the spring for closing the gate.Thus, the gate is closed by the spool until the resin pressure rises up to a certain level.

Abstract: A laminated core product producing apparatus wherein a projection is formed on part of a strip of core sheet material and core sheets are punched out of the strip and assembled in a linearly moving stack into the laminated core product by making use of the mutual fitting and crimping of the projections on the core sheets. The dimension of the laminated core product in the direction of the thickness of the core sheets is determined by controlling the intermittent punching out of the projections. A marking mechanism selectively marks a portion of the lateral side edge of a core sheet to be punched out, and at least one proximity sensor provided adjacent the stacked core sheets being assembled into the core product produces a signal corresponding to the distance of a marked core sheet from the head of the stack during movement of the marked core sheet along the stack.