Rectifier with slug construction and mold for fabricating same

Abstract

A rectifier designed for leadless surface mounting on a P.C. board has a cylindrical body situated between two disk-like end parts. The end parts extend radially beyond the surface of the body defining a recess adapted to receive epoxy compound. A plurality of rectifiers are situated end-to-end within elongated cylindrical cavities in a mold. The end parts cooperate with the cavity walls to seal each individual recess when the mold halves are closed. Openings in the cavity wall aligned with each recess permit epoxy compound to enter each recess and be cured. Leads may be attached to the end parts after the molding operation to convert the rectifier into an axial lead device, if required.

I claim: 
     
       1. A rectifier comprising a .[.substantially cylindrical.]. body situated between first and second end parts to form a unit, said end parts extending radially beyond the surface of said body and defining therebetween a recess adapted to receive a molding compound applied by injecting the compound into the recess when the unit is situated within a .[.substantially cylindrical.]. cavity in a mold, the cavity having .[.a diameter.]. .Iadd.dimensions .Iaddend.substantially equal to the .[.diameters.]. .Iadd.corresponding dimensions .Iaddend.of said end parts and being substantially longer than said unit, the end parts cooperating with the cavity walls to substantially seal said recess from the remainder of the cavity, the compound being injected into the recess through an opening in said cavity wall aligned with the recess. 
     
     
       2. The rectifier of claim 1, wherein said body comprises a diffused silicon dice sandwiched between substantially cylindrical slugs and a layer surrounding said body and covering the termination junctions between said dice and said slugs. 
     
     
       3. The rectifier of claim 2, wherein said end parts comprise substantially disk-like copper members. 
     
     
       4. The rectifier of claim 3, wherein said slugs are composed substantially of copper. 
     
     
       5. The rectifier of claim 4, wherein said end parts are integral with said slugs. 
     
     
       6. The rectifier of claim 2, wherein said slugs are composed substantially of molybdenum. 
     
     
       7. The rectifier of claim 1, further comprising leads attached to said end parts. 
     
     
       8. The method of applying molding compound to a plurality of electrical components of the type comprising a .[.substantially cylindrical.]. body situated between end parts radially extending beyond the surface of the body to form a recess therebetween adapted to receive the compound, the method comprising the steps of placing the components, end-to-end, in a .[.substantially cylindrical.]. cavity within a mold, the .[.diameter.]. .Iadd.dimensions .Iaddend.of the cavity being substantially equal to the .[.diameters.]. .Iadd.corresponding dimensions .Iaddend.of the end parts, the end parts of each component cooperating with the cavity wall to substantially completely seal each recess, separately introducing the compound into each of the recesses and curing the compound. 
     
     
       9. The method of claim 8, further comprising the step of attaching leads to said end parts of each component. 
     
     
       10. A mold for applying compound to a plurality of electrical components of the type comprising a .[.substantially cylindrical.]. body situated between end parts radially extending beyond the surfaces of the body to form a recess therebetween adapted to receive the molding compound, the mold comprising an elongated.[., substantially cylindrical.]. cavity adapted to receive the components, end-to-end, .[.the diameter.]. .Iadd.dimensions .Iaddend.of said cavity being substantially equal to the .[.diameters.]. .Iadd.corresponding dimensions .Iaddend.of the end parts, the end parts cooperating with the cavity wall to substantially seal each recess, a plurality of spaced openings in said cavity wall, each of said openings being aligned with a different one of said recesses to permit the molding compound to enter therein. 
     
     
       11. The mold of claim 10, further comprising a conduit situated proximate one side of said cavity and connected to each of said openings, said conduit being adapted to transfer fluid molding compound from outside said mold to said openings. 
     
     
       12. The mold of claim 11, further comprising a second cavity situated on the opposite side of said conduit, said second cavity having a plurality of openings therein connected to said conduit. .Iadd.13. The rectifier of claim 1, wherein said body is substantially cylindrical. .Iaddend. .Iadd.14. The rectifier of claim 1, wherein said cavity is substantially cylindrical. .Iaddend. .Iadd.15. The method of claim 8, wherein said body is substantially cylindrical. .Iaddend. .Iadd.16. The method of claim 8, wherein said cavity is substantially cylindrical. .Iaddend. .Iadd.17. The mold of claim 10, wherein said body is substantially cylindrical. .Iaddend. .Iadd.18. The mold of claim 10, wherein said cavity is substantially cylindrical. .Iaddend.