Radiation imaging sensor

Patent metadata

Field	Value
Publication number	US-10041837-B2
Application number	US-201414547581-A
Country	US
Kind code	B2
Filing date	Nov 19, 2014
Priority date	Nov 22, 2013
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

The present invention relates to a radiation imaging sensor with at least one detection element, which is implemented on a substrate as a micromechanical resonator and which absorbs the radiation to be detected. The resonator is set into a resonant oscillation with an excitation device and a shift in the resonance frequency of the detection element under exposure to radiation is detected with a detection device. The radiation sensor is characterized by the fact that it comprises a scanning device with a single-axis or multi-axis tiltable scanning element. The facility to tilt the device means that the detection element can be used to detect radiation from different directions. The imaging sensor can be realized in a compact manner and be economically produced.

First claim

The invention claimed is:

1. An imaging radiation sensor comprising
at least one detection element implemented on a MEMS substrate as a micromechanical resonator configured to absorb radiation,
at least one excitation device adapted to set the at least one detection element into resonant oscillation,
at least one detection device configured to detect a shift in the resonance frequency of the detection element occurring upon absorption of the radiation,
a scanning device with a single-axis or multi-axis tiltable scanning element so as to detect radiation from different directions with the detection element,
a base substrate bonded to a side of said MEMS substrate opposite said at least one detection element; and
a cover substrate bonded to the MEMS substrate, wherein the MEMS substrate is bonded onto the base substrate so that the cover substrate, the MEMS substrate and the base substrate form a hermetically sealed cavity with the at least one detection element and the scanning element arranged within the hermetically sealed cavity,
wherein the excitation device comprises as least one electrode configured to set the detection element into resonant oscillation via electrostatic forces, and
wherein the detection device comprises a sensor electrode configured to capacitively detect the shift of the resonance frequency of the detection element.

2. The radiation sensor according to claim 1 ,
characterized in
that the scanning element is formed by a frame which is suspended so as to tilt and wherein the detection element is fixed on the scanning element.

3. The radiation sensor according to claim 1 ,
characterized in
that the scanning element is implemented as a mirror element, by means of which the detected radiation is aimed directly or via one or a plurality of deflection elements onto the detection element.

4. The radiation sensor according to claim 1 ,
characterized in
that at least one reference detection element with a further excitation device and a further detection device is arranged in the cavity, wherein the reference detection element does not lie in the beam path of the detected radiation.

5. The radiation sensor according to claim 1 ,
characterized in
that the detection element and the scanning element are implemented on a common substrate.

6. The radiation sensor according to claim 1 ,
wherein the base substrate, the MEMS substrate with the at least one detection element and the scanning element and the cover substrate are connected together.

7. The radiation sensor according to claim 1 ,
characterised in
that the cavity contains a getter material.

8. The radiation sensor according to claim 1 ,
characterized in
that the detection element is formed by a mechanically elastic spring element which is suspended or clamped on one side or on two sides.

9. The radiation sensor according to claim 1 ,
characterized in
that the detection element is formed by a mass suspended via one or a plurality of torsional springs.

10. The radiation sensor according to claim 1 ,
characterized in
that the detection arrangement comprises a phase-locked loop for regulating the micromechanical resonator, with which the resonator is maintained at resonance.

11. The radiation sensor according to claim 1 ,
characterized in
that the radiation sensor comprises a plurality of the detection elements with excitation device and detection device, which are arranged on the MEMS substrate as a one-dimensional or two-dimensional array.

Assignees

• Fraunhofer Ges Forschung

Inventors

• Hofmann Ulrich
• Weiss Manfred
• Janes Joachim
• Senger Frank

Classifications

• G01J5/44

  using change of resonant frequency, e.g. of piezoelectric crystals · CPC title

• G01J5/0871

  Beam switching arrangements; Photodetection involving different fields of view for a single detector · CPC title

• G01J5/084

  Adjustable or slidable · CPC title

• G01J2005/0077

  Imaging · CPC title

• G01J5/047 Primary

  Mobile mounting; Scanning arrangements · CPC title