Backside thinning of image array devices

DETAILED DESCRIPTION OF THE INVENTION The context of the invention is illustrated in FIG.
1 where there is shown an example of an electron bombarded active pixel array component including a vacuum enclosure 3 which houses a photocathode 12 such as a GaAs, an InP/InGaAs, a transferred electron photocathode, or a multi-alkali photocathode, in proximity focus with a specialized active pixel array sensor chip 13 which forms the anode for receiving the proximity focused photoelectrons from photocathode 12 to which an acceleration voltage 37 is applied.
In accordance with this invention the active pixel array sensor 13 is mounted with its backside 10 facing the photocathode 12.
Photoelectrons 15 are emitted from photocathode 12 in response to incident light illustrated as arrows designated 16.
Optical components, not shown, are typically employed to form an optical image on the photocathode.
Any projection system may be used to place an image on the photocathode.
The photoelectrons 15 are accelerated by an applied voltage to sufficient energy to allow electron gain in the chip in which the active pixel sensor 13 is found.
The accelerating voltage 17 (or photocathode bias from a power supply not shown) applied to the photocathode 12 is preferably negative with respect to the chip.
This permits biasing the chip to near, or at ground to simplify interfacing with other components.
Control signals and bias voltages 18 are applied to active pixel sensor 13 and a video output signal 20 may be taken off sensor 13.
The base of vacuum device 12 is a transparent faceplate 21 and vacuum enclosure sidewalls 22 extend between the transparent faceplate 21 on which the photocathode 12 is positioned and header assembly 23, on which the active pixel sensor chip 13 is positioned.
The header assembly 23 also provides means for electrical feedthroughs for applying control and bias voltages 18 to the active pixel array sensor chip 13.
The control electronics for reading out and operating the pixel array are conventional for the purpose and not essential to understanding the present invention