Abstract: An x-ray and gamma-ray radiation energy imaging device has its semiconductor detector substrate and semiconductor readout/processing substrate both mounted on opposite sides of, and electrically communicating through, an intermediate substrate. The substrates are all substantially planar with the top plan perimeter of the semiconductor readout/processing substrate falling within the top plan shadow perimeter of the corresponding semiconductor detector substrate with which it electrically communicates. Additionally, all of the readout/processing circuitry contacts of the semiconductor readout/processing substrate are disposed on the surface of the semiconductor readout/processing substrate that electrically communicates with the intermediate substrate. Substantially all electrical communication to and from the semiconductor readout/processing substrate is routed through the intermediate substrate. The intermediate substrate is a printed circuit board or similar construct.
Type:
Grant
Filed:
May 23, 2002
Date of Patent:
March 13, 2007
Assignee:
Oy AJAT Ltd
Inventors:
Konstantinos Spartiotis, Kimmo Petteri Puhakka
Abstract: The radiation detector/imaging substrate arrays in an x-ray and gamma-ray radiation energy imaging device are described which use an electrically conductive adhesive to provide electron charge signaling continuity between the detector and read-out substrates of the device. The present device utilizes a plurality of electrically conductive bonds each discretely connecting a pixel contact in the pixel pattern to a signal contact in the signal contact pattern, the bonds being an electrically conductive adhesive. This bonding technique is especially useful in detection/imaging arrays having detector substrates comprising Cadmium and Tellurium compositions. The present invention is practicable with semiconductor detector and read-out substrates with or without “bumped” electrical contacts. The electrically conductive bonds utilize either isotropically or anisotropically conductive adhesives.
Abstract: A high voltage switching power supply (10) for an X-ray/Gamma ray imaging camera provides high voltage switching and depolarization capabilities. The power supply includes a high voltage polarity switching and an image detector charge bleeding circuit (90) and is particularly useful with high energy radiation imaging cameras utilizing Cd—Te based detector substrates, especially substrates with blocked contacts, where charge accumulation in the detector material reduces imaging efficiency.
Abstract: An electrically pumped VCSEL and a method of its fabrication are presented. The VCSEL comprises an active cavity material sandwiched between top and bottom DBR stacks, the top DBR having at least one n-semiconductor layer. The device defines an aperture region between the structured surface of the active cavity material and the n-semiconductor layer of the top DBR stack. The structured surface is formed by a top surface of a mesa that includes at least the upper n++ layer of a p++/n++ tunnel junction and the surface of a p-type layer outside the mesa. The structured surface is fused to the surface of the n-semiconductor layer of the DBR stack due to the deformation of these surfaces, thereby creating an air gap in the vicinity of the mesa between the fused surfaces.
Type:
Grant
Filed:
March 6, 2003
Date of Patent:
May 10, 2005
Assignee:
EPFL
Inventors:
Elyahou Kapon, Vladimir Iakovlev, Alexei Sirbu, Alok Rudra