Hermetic terminal assembly and associated method of manufacture
Several embodiments of a hermetic terminal assembly are disclosed and an associated method. The terminal assembly includes a metallic body that has body a bottom portion. The bottom portion includes an interior surface, an exterior surface and at least one opening. The terminal assembly also includes a current-conducting pin extending longitudinally through the opening, and a prefabricated dielectric retainer receiving the pin and covering at least a portion of the interior surface and surrounding at least a portion of the opening. The terminal assembly includes a dielectric epoxy bonding to the body, the retainer and the pin, and providing a seal between the pin and the opening in the bottom portion through which the pin is extending. In another embodiment, the prefabricated retainer may be omitted entirely.
1. A hermetic terminal assembly comprising:
a body having a bottom portion, the bottom portion comprising an interior surface, an exterior surface and at least one opening having a wall;
a prefabricated dielectric retainer located adjacent to the interior surface of the bottom portion of the body and surrounding at least a portion of the wall, the retainer including at least one aperture therethrough;
a current-conducting pin extending longitudinally through the opening in the body and the aperture of the retainer; and
a dielectric epoxy bonding to the body, the retainer and the pin, and providing a seal between the pin and the opening in the bottom portion through which the pin is extending.
2. The terminal assembly of claim 1 , wherein the exterior surface of the bottom portion includes a countersunk portion sealed with the epoxy.
3. The terminal assembly of claim 1 , wherein the retainer includes an annular countersunk portion adjacent to the aperture that is sealed with the epoxy.
4. The terminal assembly of claim 1 , further including an adhesive on the interior surface of the body.
5. The terminal assembly of claim 1 , further including an adhesive on the exterior surface of the body.
6. The terminal assembly of claim 1 , wherein the retainer is formed from a plastic resin.
7. The terminal assembly of claim 1 , wherein the retainer is formed from a ceramic.
8. The terminal assembly of claim 3 , wherein the retainer includes a cavity communicating with the countersunk portion and sealed with the epoxy.
9. The terminal assembly of claim 3 , wherein the countersunk portion receives at least a portion of the wall of the body.
10. A hermetic terminal comprising:
a body comprising an interior surface, an exterior surface, at least one opening, and an annular recess located in the exterior surface adjacent to the opening;
a current conducting pin extending longitudinally through the opening; and
a dielectric plastic covering at least portions of each of the interior surface, the opening and the annular recess of the body, the plastic bonding to both the body and the pin and providing a hermetic seal between the pin and the opening.
11. The terminal assembly of claim 10 , wherein the plastic is selected from the group consisting of polyphenyl sulfide, liquid crystalline polymers, polypropylenes, thermoplastic polyolefins, and polyvinylchlorides.
12. The terminal assembly of claim 10 , wherein the plastic is epoxy.
13. The terminal of claim 10 wherein the hermetic seal is of at least about 1×10 −6 atm cc/sec He.
14. The terminal assembly of claim 10 , wherein the plastic is molded in situ.
15. The terminal assembly of claim 10 , wherein an adhesive is interposed between the plastic and the body.
16. The terminal assembly of claim 15 , wherein an adhesive is interposed between the plastic and the pin.
17. The terminal assembly of claim 16 , wherein the adhesive is an electrically insulating epoxy.
18. A hermetic terminal comprising:
a body comprising at least one opening therethrough and an annular recessed portion located adjacent to the opening in an exterior surface of the body;
a current-conducting pin extending through the opening; and
a dielectric epoxy disposed in the opening and in the annular recessed portion, the epoxy bonding to the body and the pin and providing a hermetic seal between the body and the pin.
19. The terminal of claim 18 wherein the hermetic seal is of at least about 1×10 −6 atm cc/sec He.
20. The terminal assembly of claim 18 , further comprising a dielectric retainer placed over the pin and adjacent to an interior surface of the body.
21. The terminal assembly of claim 20 , wherein the retainer includes an annular countersunk portion sealed with the epoxy.
22. The terminal assembly of claim 21 , wherein the retainer includes a cavity communicating with the countersunk portion and sealed with the epoxy.
23. The terminal assembly of claim 20 , further comprising an adhesive covering at least a portion of an exterior surface of the body.
24. The terminal assembly of claim 20 , further comprising an adhesive covering at least a portion of the interior surface of the body.