Method of using an improved solder to bridge a nonmetallic gap between metallic surfaces, said improved solder, and an improved solder connection to bridge a nonmetallic gap between metallic surfaces

#The invention relates in general to an improved solder and to a method of using the improved solder to bridge a non-metallic gap between metallic surfaces and in particular to a solder imbedded with metallic fibers and to a method of using the solder imbedded with the metallic fibers to bridge the nonmetallic gap and connect the two separated metallic surfaces.

#Currently, electrical solder connections are made with a lead/tin or other metal alloy. Problems exist with this method. That is, solder will only adhere to metallized surfaces as for example, copper. Moreover, solder exhibits cohesion effects that tend to make the solder form into globs. Then too, solder is typically "soft" (that is, malleable). The first two effects make it difficult to bridge nonmetallic gaps greater than 0.1 millimeter between metallic surfaces. The third effect makes the connection weak or of low tensile and shear strength.

#The general object of this invention is to provide an improved solder that can bridge a nonmetallic gap between metallic surfaces or electronic components that ordinarily cannot be bridged with conventional solder. Another object of the invention is to add structural strength to electronic component solder connections. A still further object of the invention is to provide an improved solder that can bridge the non metallic gaps between metallic surfaces such as circuit ground planes and circuit board traces, and that can join electronic components to circuit boards where a non metallic gap may exist originating from misshaped, positional or placed components.

#FIG. 1 shows an attempt at soldering a gap with conventional solder.

#FIG. 2 shows the same gap as in FIG. 1 except that the gap is bridged with the improved solder.

#FIG. 3 shows the improved solder.

#Referring to FIG. 1, metallized surfaces 10, 12, are separated by a nonmetallic gap 14. Conventional solder 16, and 18 is placed across the metallized surfaces 10, and 12 and heat is applied to melt the solder, 16 and 18. When the solder melts, it tends to glob into two separate balls because of cohesive forces and the gap, 14 between the two metallized surfaces 10, and 12 remains. Only when the diameter of the glob becomes as large as the gap, 14 will it bridge the gap. This requires an excessive amount of solder.

#Referring to FIG. 2, the two metallized surfaces 10, and 12 have a nonmetallic gap, 14 between them. Improved solder, 20 is placed on the gap, 14. Heat is applied and the improved solder, 20 flows. As the non melting metallic fibers in the improved solder, 20 have a higher melting point than the solder, metallic fibers bridge the gap, 14 and the improved solder, 20 connects the two separated metallic surfaces, 10 and 12. The metallic fibers provide metal surfaces that satisfy the cohesive forces of the improved solder, 20 and provide ample locations for the improved solder to flow or "wet." The cohesive forces of the improved solder stretch out the fibers across the gap to yield a planar bridge gap; that is, the gap below the metal does not fill with solder.

#Referring to FIG. 3, the improved solder, 20 includes solder imbedded with metallic as, for example gold, silver, or copper fibers. These fibers can be composed of any metallic material that the solder will stick to, and the metallic fibers can be of varying diameter and length to suit the application. For example, the length of the fiber can be varied depending on the width of the gap being traversed. The fibers can be randomly oriented or given a preferred orientation. The solder composition can also be varied using combinations of lead, tin, silver, indium, etc. Flux can also be added to the solder core to help flow the solder onto the metallic surfaces.