Unitary vacuum tube incorporating high voltage isolation
A housing for microelectronic devices requiring an internal vacuum for operation, e.g., an image detector, is formed by tape casting and incorporates leads between interior and exterior of the housing where the leads are disposed on a facing surface of green tape layers. Adjacent green tape layers having corresponding apertures therein are stacked on a first closure member to form a resulting cavity and increased electrical isolation or channel sub-structures are achievable by forming adjacent layers with aperture dimension which vary non-monotonically. After assembly of the device within the cavity, a second closure member is sealed against an open face of the package in a vacuum environment to produce a vacuum sealed device.
1. The method of manufacturing a packaged vacuum microelectronic device, said device comprising a rectangular photocathode and a rectangular semiconductor die, comprising the steps of
fabricating a housing of ceramic material and forming a cavity within said housing, wherein said die and said cavity exhibit similar geometric symmetry,
inserting said semiconductor die into said housing,
orienting said die within said housing whereby the volume of said housing is efficiently employed, and
drawing a vacuum in said cavity.
2. A method in accordance with claim 1 in which said cavity is defined by non-monototonically arranged planar insulating ceramic layers.
3. The method of creating a unitary vacuum microelectronic imaging device comprising:
laminating a structure comprising first and second planar end plates and a plurality of insulating intermediate planar plates disposed therebetween, one of said end plates comprising a transparent wall with a photocathode on a surface,
forming a cavity in said laminated structure by positioning at least three of said intermediate plates against each other, each of said intermediate plates being selected as to have an aperture therein as to form a cavity in said laminated structure when said plates are positioned against each other, said at least three plates having apertures that vary non-monotonically when positioned in series with one another,
positioning and bonding said transparent end plate onto an intermediate plate with said photocathode surface facing the cavity
positioning and bonding a microelectronic device at the other said end plate opposite to said end plate with a transparent wall, and
creating a vacuum pocket within said cavity.
4. The method of claim 3 including bonding said transparent end plate onto an intermediate plate with a soft metal layer.
5. The method of claim 3 including placing a getter material within said vacuum area of said unitary vacuum microelectronic imaging device.
6. A method of operating a caseless high voltage microdevice comprising
creating apertures in at least three insulating ceramic planar plates,
positioning the apertures of said plates together as to create an internal cavity in which said apertures vary non-monotonically when said planar plates are positioned together,
placing a transparent end layer having a photocathode on a surface thereof at one end of said cavity with the photocathode surface facing said cavity,
placing an anode having a semiconductor chip at the other end of said cavity,
drawing a vacuum in said cavity and sealing the transparent end layer to an adjacent insulating ceramic planar plate,
positioning refractory leads through vias in at least one of the lateral walls of the microdevice from the interior to the exterior of the wall to feed signals out of said device, and
connecting a high negative voltage through the back of said microdevice to said photocathode while isolating the voltage from the remaining external surfaces of the microdevice and connecting voltages within about 20 V of ground potential to said semiconductor chip.
7. A method in accordance with claim 6 in which the transparent end layer is sealed to an adjacent ceramic planar plate using a soft metal.
8. A method in accordance with claim 6 in which an array of electron sensitive elements is present in the semiconductor chip and image information is created by feeding electron information along vias to a display system.