Abstract: A device for making or undoing welds between a component with several galvanic connections and a support is particularly suited for surface mounting. In order to direct a stream of hot gas or infrared radiation accurately onto the connections of the component and corresponding weld surfaces, a mask is provided which has openings that exactly match the configuration of the weld surface. Preferably, in the case of hot-air operation, a light source is arranged behind the mask in such a way that the predetermined pattern is reproduced exactly on the substrate in the form of points of light for positioning purposes. In one embodiment, the mask comprises two pairs of horizontally adjustable shields, the two pairs of shields being arranged at an angle of 90 degrees, the shields being made of a material of low thermal conductivity.

Abstract: A method and apparatus for reflow-soldering of printed circuit boards are disclosed. A printed circuit board having electronic parts with lead wires having low temperature resistance alone or together with electronic part of high temperature resistance can be soldered according to the reflow-soldering method in a specifically designed heating zone involving plural preheating chambers and a reflowing chamber while maintaining a difference in temperature between the obverse surface and the reverse surface of the board without causing any soldering failure and any environmental pollution.

Abstract: There is disclosed an oven comprising at least one halogen lamp (4a) provided with a far infrared coating and at least one halogen lamp (4b) without a far infrared coating, both halogen lamps (4a, 4b) being disposed in a grill chamber having on the front a door which can be opened and closed.

Abstract: A tungsten halogen lamp producing infra red radiation, for example for cooking or heating, has an envelope of high silica content material sealed at each end by a pinch seal. A gas fill is at a room temperature pressure of 250-750 mm Hg. A portion of the envelope at each end is clear and the rest contains an opacifier which reduces transmission of visible light. A suitable opacifier is red, being produced by the reduction of copper oxide dispersed in the high silica content material. The envelope is produced by butt joining clear end sections and a tube of material containing opacifier.

Abstract: A heat-treatment furnace comprising a process tube for containing an object of treatment, a heater surrounding the process tube, and an infrared impermeable member located on the process tube side of the heater and at least one the side of an open end of the process tube through which the object of treatment is carried in and out.

Abstract: An electric far-infrared heater has a plate-like porous metallic panel formed by an electroforming process installed in a box-like housing over an electric heating element therein. The panel is heated by the element and has its outer surface covered by a porous ceramic far-infrared emitting layer of Al.sub.2 O.sub.3, TiO.sub.2, Cr.sub.2 O.sub.3, MgO, ZrO.sub.2, SiO.sub.2 or mixtures thereof. A stream of gas supplied to the interior of the housing is heated by the element and passes through the porous panel and far-infrared layer for discharge onto the object being heated.