Abstract:
In an electric resistance heating element, the invention relates to the assembly of a resistor coil to a terminal pin to provide mechanical and electrical connection therebetween. The assembly is particularly suited for use in strip heaters wherein the coil is connected to the flat head of a terminal bolt. A group of convolutions of the resistor coil are flattened against the bolt head and welded thereto by a resistance welding operation. In the method disclosed, the shank of the bolt is disposed within an opening in one welding electrode of a welding machine with the bolt head overlying the tip of such electrode, and the group of convolutions of the coil are placed against the flat surface of the bolt head. The other welding electrode has a rounded tip and as this electrode is moved toward said one electrode, its rounded tip flattens the group of convolutions in overlapping relation on the flat surface of the bolt head. With the flattened convolutions and the bolt head firmly gripped between the welding electrodes, welding current is caused to flow between the electrodes to weld the flattened convolutions to the flat surface of the bolt head. Those flattened convolutions at the center of the rounded tip of said other electrode are fully fused to the flat surface of the bolt head, whereas the convolutions off the center of such rounded tip have a stick weld to the flat surface. Thus, not only is a low resistance electrical connection made by the fully fused convolutions, but a good mechanical connection is made by the stick-welded convolutions.
Abstract:
A connector wire is bonded to a solder electrode by pressing the end portion thereof to the solder electrode by using a capillary while the capillary is heated up to a temperature not less than the melting point of the solder, by melting the solder electrode and then by cooling the whole bonding area of the connector wire and the solder electrode, thereby the end portion of the connector wire is buried in the solder electrode and is firmly fixed thereto.
Abstract:
A PLURALITY OF CONNECTIONS FROM ELECTRICALLY CONDUCTIVE LANDS ON AN INSULATING SUBSTRATE TO THE CONTACTS OF A SOLID STATE DEVICE ARE FORMED IN ONE OPERATION BY FIXEDLY POSITIONING THE DEVICE ON, OR IN A CAVITY WITHIN, THE SUBSTRATE. A DECAL, INCLUDING A BACKING PLATE WITH A PLURALITY OF CONDUCTIVE STRIPS WHICH CAN BE ADHERED TO THE PLATE BY MEANS OF A SOLUBLE ADHESIVE, IS POSITIONED OVER THE DEVICE BEARING SUBSTRATE WITH THE STRIPS IN REGISTRY WITH RESPECTIVE CONTACTS AND LANDS. THE STRIPS ARE BROUGHT INTO CONTACT WITH RESPECTIVE CONTACT AND LAND SURFACE PORTIONS AND SUBJECTED TO HEAT AND PRESSURE SUFFICIENT TO CAUSE BONDING THEREBETWEEN. THEREAFTER, THE DECAL BACKING PLATE MAY BE REMOVED FROM THE STRIPS, AS BY DISSOLVING THE ADHESIVE, LEAVING THE STRIPS FIRMLY BONDED TO THE CONTACTS AND LANDS AND BRIDGING THE SPACE THEREBETWEEN, WHEREBY THE LANDS ARE CONNECTED TO THE CONTACTS THROUGH THE STRIPS.
Abstract:
A METHOD OF BONDING IS DESCRIBED, PARTICULARLY SUITABLE FOR BONDING THE CONDUCTORS OF AN INTEGRATED CIRCUIT MODULE, FOR EXAMPLE, TO A SET OF CONDUCTORS SUPPORTED ON A SUBSTRATE. IN CONVENTIONAL TECHNIQUES A MODULE IS COMPRESSION WELDED TO A PATTERN OF PROTUBERANCES FORMED ON A SET OF CONDUCTORS, AND IT IS FREQUENTLY FOUND THAT UNDER NORMAL MANUFACTURING TOLERANCES A HIGH PROPORTION OF WELD FAILURES MAY BE EXPECTED. THE PRESENT DISCLOSURE ENVISAGES THE FORMATION OF PILLARS OF A SOFT, READILY DEFORMABLE MATERIAL, SUCH AS A TIN/LEAD EUTECTIC, BETWEEN THE CONDUCTORS SO THAT DURING COMPRESSION WELDING THE PILLARS ARE DEFORMED UNDER THE WELDING PRESSURE, THUS ENABLING ALL THE CONDUCTORS TO MAKE GOOD ELECTRICAL CONTACT WITH THEIR RESPECTIVE PILLARS, DESPITE ANY DISCREPANCIES IN HEIGHT THAT MAY EXIT AS BETWEEN THE PILLARS. THE USE OF AN OXIDIZABLE MATERIAL, SUCH AS THE TIN/LEAD EUTECTIC AS NOTED ABOVE, COULD RESULT IN THE FORMATION OF AN OXIDE LAYER WHICH WOULD PREVENT A GOOD ELECTRICALLY CONDUCTIVE BONDING BEING ESTABLISHED, AND IN THIS CASE IT IS PROPOSED TO FORM A LAYER OF AN OXIDATION-RESISTANT MATERIAL, SUCH AS GOLD, OVER ANY EXPOSED CONTACTING SURFACE OF A PILLAR. THIS LAYER, BESIDES BEING ITSELF RESISTANT TO OXIDATION PREFERABLY ALSO PRESENTS A HARD SURFACE TO THE CONDUCTOR TO WHICH IT IS TO BE BONDED AND THE WELDING PRESSUR IS SUFFICIENT TO ENSURE THAT THIS SURFACE BREAKS THROUGH ANY OXIDE LAYER PRESENT ON THE SURFACE OF THE CONDUCTOR, A FEATURE OF IMPORTANCE WHERE THE CONDUCTOR IS, FOR EXAMPLE, OF ALUMINUM.
Abstract:
681,586. Soldering. SVENSKA AKTIEBOLAGET GASACCUMULATOR. Nov. 3, 1950 [Nov. 3, 1949 ; Feb. 13, 1950], No. 26907/50. Class 83 (iv). A method of making a soldered joint between two metallic members in one of which an aperture is provided comprises inserting a metal pin consisting of two axially disposed parts with different melting- points, the part having the lower melting-point being melted to form, on solidification, a soldered joint between the high melting-point part of the pin and adjacent surfaces of the metallic members. For joining a metal plate 1 and a beam 2 an aperture is made in the plate 1 and a metal pin, comprising a part 3 of steel, brass or copper and a part 4 of solder (Fig. 2) is placed in an electric-arc apparatus and inserted in the aperture so as to rest on the beam 2. On initiation of the arc the solder part of the pin melts and forms, on solidification, a joint between the plate, beam and the pin. In another embodiment an electrical connector comprising a copper wire 5 having contact shoes 6 at each end is attached to a rail, beam, tube, &c. by inserting a metal pin 11 (Fig. 5) through an aperture 10 in the contact shoes and effecting a soldered joint as hitherto. The pin 11 may be of bronze having a solder portion 12 which carries a flux 13 in a recess covered by a lid 14 also of solder. An annular notch 15 in the pin enables the part 10 to be broken off after soldering. The contact shoes may be provided with a flux 17 (Fig. 8) which is retained between solder covers 18 and 18a pressed into the aperture below the surface 7. For this connection a pin of the type shown in Fig. 2 may be used. The cover 18 may be bowl-shaped to receive the flux and enclosed by a flat cover held by turning over the rim of the bowl-shaped cover 18. Specification 681,585 is referred to.