Abstract: During the pre-soldering or tinning of printed circuit boards, as a rule, also the drill holes or bores and, in particular, the through-metallized drill holes are filled in an undesirable manner with solder. This solder must be removed before mounting the electrical components or elements upon the printed circuit boards. A simple apparatus is disclosed for this purpose, affording a faultless de-soldering of the drill holes, without deleteriously affecting the properties of the solder material. The printed circuit boards, in a condition where the solder applied during the pre-soldering operation is still molten, are accelerated at least once and thereafter suddenly brought to standstill in such a fashion that the excess solder is knocked or propelled out of the drill holes.

Abstract: During the pre-soldering of printed circuit boards, as a rule, also the drill holes or bores and, in particular, the through-metallized drill holes are filled in an undesirable manner with solder. This solder must be removed before mounting the electrical components or elements upon the printed circuit boards. A simple method is disclosed for this purpose, affording a faultless de-soldering of the drill holes, without deleteriously affecting the properties of the solder material. The printed circuit boards, in a condition where the solder applied during the pre-soldering operation is still molten, are accelerated at least once and thereafter suddenly brought to standstill in such a fashion that the excess solder is knocked or propelled out of the drill holes.

Abstract: The solder applying apparatus enables applying solder to both sides or faces of printed-circuit boards travelling essentially in horizontal direction through a production or manufacturing line, and which circuit boards are not yet equipped with electrical components or the like. The apparatus contains a solder applicator means or device where liquid solder is pumped from a supply container in such a quantity that a solder wave forms over an outlet or discharge opening of the applicator device. This solder wave extends beyond the feed or transport plane of the printed-circuit boards. At the side walls of the applicator solder device there are mounted guide elements formed of metal plating or sheet metal which extend beneath the feed plane, the solder flowing-off by means of such guide elements. The angle of inclination of the metal guide elements is adjustable with respect to the feed plane. Also the spacing between the discharge opening of the applicator solder device and the feed plane is variable.

Abstract: The arrangement comprises a support at which there is mounted an induction loop through which flows a high-frequency alternating current. By displacing the support or the circuit board possessing the contact pins which are to be soldered, a multiplicity of contact pins at which contact is to be made are simultaneously brought together with the solder material and the solder eyelets of the contact locations into the range of influence of the magnetic alternating field. By appropriately constructing the induction loop there is obtained a simultaneous uniform heating of the contact pins and the contact locations. The arrangement thus renders possible a simultaneous faultless soldering of the contact pins of one or a number of pin rows of multipoint connectors mounted at the circuit boards.