Image intensifier unitube for intensified charge transfer device and method of manufacture

Claim 1

A method of manufacturing an image intensifier unitube for intensified charge transfer device, the steps comprising: providing a ceramic tube base having a plurality of internal conductors built therein electrically connected between a plurality of external pins and a plurality of mounting pads mounted on an inner centrally raised portion thereof; providing a generally cylindrical ceramic tube wall; brazing said tube base to said tube wall by a circular Kovar ring wherein said Kovar ring has an inner spring loaded contact; bonding a charge transfer device and a plurality of beam leads therefrom on said inner centrally raised portion, said plurality of beam leads being electrically connected to said plurality of mounting pads; placing a metal shield over a thick outer portion of said charge transfer device and along the inside walls of said inner centrally raised portion; placing a generally flat cathode faceplate with photocathode layer and metallized layer thereon and said ceramic tube base and ceramic tube wall in separate sections inside an ultra high vacuum processing chamber; baking said combined tube wall and tube base with CTD mounted thereon at an upper limit temperature determined by the stability of the CTD performance characteristics to decontaminate the tube body; heating said cathode faceplate and photocathode while mounted on a metal pedestal to just below the decomposition temperature for the photocathode materials to create an ultra clean surface on the photocathode semiconductor; activating said photocathode with alternate applications of cesium and oxide at room temperature while monitoring the photoemissive yield; applying cesium to the tube body to condition said tube body interior and to compensate for the cesium loss during a subsequent step of transferring said cathode faceplate and photocathode from the metal pedestal to mate with the tube body; positioning and sealing said generally flat cathode faceplate by sealing edges on said tube wall and said faceplate to vacuum seal the interior of said unitube body and to place said photocathode in proximity focus with said charge transfer device; potting the outside of said tube wall with a silicon rubber insulator to prevent high voltage breakdown along the outside of said unitube body; and slowly applying a cathode high voltage to said photocathode to condition the interior of said unitube.

Claim 2

A method of manufacturing an image intensifier unitube for intensified charge transfer device, the steps comprising: providing a ceramic tube base having a plurality of internal conductors built therein electrically connected between a plurality of external pins and a plurality of mounting pads mounted on an inner centrally raised portion thereof; providing a generally cylindrical ceramic tube wall; brazing said tube base to said tube wall by a circular Kovar ring wherein said Kovar ring has an inner spring loaded contact; bonding a charge transfer device and a plurality of beam leads therefrom on said inner centrally raised portion, said plurality of beam leads being electrically connected to said plurality of mounting pads; placing a metal shield over a thick outer portion of said charge transfer device and along the inside walls of said inner centrally raised portion; placing a generally flat cathode faceplate with photocathode layer and metallized layer thereon and said ceramic tube base and ceramic tube wall in separate sections inside an ultra high vacuum processing chamber; baking said combined tube wall and tube base with CTD mounted thereon at an upper limit temperature determined by the stability of the CTD performance characteristics to decontaminate the tube body; heating said cathode faceplate and photocathode while mounted on a metal pedestal to just below the decomposition temperature for the photocathode materials to create an ultra clean surface on the photocathode semiconductor; activating said photocathode with alternate applications of cesium and oxide at room temperature while monitoring the photoemissive yield; applying cesium to the tube body to condition said tube body interior and to compensate for the cesium loss during a subsequent step of transferring said cathode faceplate and photocathode from the metal pedestal to mate with the tube body; positioning and sealing said generally flat cathode faceplate by sealing edges on said tube wall and said faceplate to vacuum seal the interior of said unitube body and to place said photocathode in proximity focus with said charge transfer device; potting the outside of said tube wall with a silicon rubber insulator to prevent high voltage breakdown along the outside of said unitube body; and slowly applying a cathode high voltage to said photocathode to condition the interior of said unitube.