Rapidly-started infrared detector

Abstract

The quick-start infrared detector comprises a Dewar window, a cold screen, an infrared chip, a loading substrate, a bottom plate, a Dewar main body, a Dewar cold finger, a Dewar inner tube seat, a throttling refrigerator mounting seat, a throttling refrigerator base, a finned tube and an optical filter, the Dewar inner tube seat is fixed on the throttling refrigerator mounting seat, the lower end of the Dewar main body is fixed on the Dewar inner tube seat, and the lower end of the Dewar cold finger is fixed on the Dewar inner tube seat. The lower end of the Dewar window is fixed at the upper end of the Dewar main body, the Dewar cold finger is fixed on a Dewar inner tube seat in the Dewar main body, the bottom plate is fixed at the upper end of the Dewar cold finger, the loading substrate is fixed on the bottom plate in the cold screen, the infrared chip is fixed on the loading substrate, and the throttling refrigerator base is arranged in the Dewar cold finger and extends out of the detector. The finned tube is wound on the outer wall of a base of the Dewar cold finger inner throttling refrigerator, micro channels are fully distributed in the loading base plate, one end of the throttling tube penetrates through the bottom plate and is connected with air inlets of the micro channels, the other end of the throttling tube is connected with the upper end of the finned tube, and air outlets of the micro channels are formed in the bottom plate in a space defined by the bottom plate and the Dewar cold finger.

Description

Technical Field

[0001] The invention relates to an infrared detector packaging structure, belonging to the field of infrared detection technology, and specifically to a packaging structure that reduces interface thermal resistance, using a throttling cooler designed to be integrated with a dewar to provide cooling to an infrared detector chip, so that the chip quickly reaches a low-temperature operating temperature. Background Art

[0002] In the prior art, a fast-start infrared detector usually uses a throttling cooler to cool the infrared detector chip. The throttling cooler is generally composed of an air inlet interface, a finned tube heat exchanger, a throttling orifice, etc. It uses high-pressure and high-purity gas as a refrigerant, which can quickly make the focal plane detector assembly reach the working temperature and continuously provide low-temperature working conditions for the detector assembly. The principle is to use the Joule-Thomson effect, through a countercurrent heat exchanger, the throttled gas pre-cools the incoming high-temperature gas, and finally reaches the boiling point of the refrigerant, that is, the working temperature of the detector assembly.

[0003] The existing throttling cooled infrared detector structure consists of a throttling cooler, a vacuum dewar housing, a cold finger, an infrared detector chip, a cold screen and an optical window.

[0004] During operation, high-pressure working fluid gas enters the throttling refrigerator, and the gas after throttling and cooling is sprayed onto the lower surface of the Dewar cold platform film. The cold energy is transferred to the chip through heat conduction to cool it down and gradually reach the working temperature. At the same time, the low-temperature gas flows along the gap between the cold finger and the base of the throttling refrigerator to pre-cool the high-pressure intake air, and finally the working fluid is liquefied to make the infrared detector chip reach a lower working temperature. The vacuum Dewar shell is used to provide a vacuum environment for the infrared detector chip to maintain low temperature and reduce heat loss. The cold shield is used to reduce external stray radiation and ensure that the infrared detector chip receives the target radiation. The optical window is used to receive external light signals and provide a signal source for the infrared detector chip.

[0005] Existing infrared detectors are usually manufactured with a cooler and a dewar package separately and then integrated and coupled. When the detector is working, the refrigerant of the throttling cooler can only reach the lower surface of the cold platform film. The cold energy needs to be thermally conducted through multiple interfaces to reach the chip. The cold energy is usually conducted from the dewar film to the chip through the substrate adhesive, and then through the loading substrate and the chip adhesive. The adhesive is usually a poor conductor of heat. The thermal conductivity of the currently commonly used adhesive is less than 1W / mk, while the thermal conductivity of the film metal and the loading substrate is usually tens or even hundreds of W / mk. The bonding interface is the main factor affecting the startup time of the infrared detector. An extra layer of adhesive interface seriously affects the thermal conduction rate of the overall structure, which is not conducive to the rapid startup of the infrared detector. Summary of the invention

[0006] The purpose of the present invention is to provide a quick-start infrared detector packaging structure, which adopts a Dewar throttling cooler integrated packaging design. The fin tube of the cooler is connected to the Dewar plate opening, the plate is welded to the loading substrate, and microchannels are processed inside the loading substrate. High-pressure refrigerant gas enters the microchannel embedded in the substrate through the plate opening and directly acts on the substrate to achieve rapid cooling of the infrared chip, thereby solving the problem of long startup time of infrared detectors in the prior art.

[0007] In order to achieve the invention purpose of this application, this application adopts the following technical solutions:

[0008] The invention discloses a quick-start infrared detector, which comprises: a dewar window, a cold shield, an infrared chip, a loading substrate, a bottom plate, a dewar body, a dewar cold finger, a dewar inner tube seat, a throttling refrigerator mounting seat, a throttling refrigerator base, a fin tube and an optical filter. The dewar inner tube seat is fixed on the throttling refrigerator mounting seat, the lower end of the dewar body is fixed on the dewar inner tube seat, the lower end of the dewar window is fixed on the upper end of the dewar body, an optical window is opened on the upper end of the dewar window, and a cold shield, an infrared chip, a loading substrate, a bottom plate, a dewar cold finger, a fin tube and an optical filter are arranged in a vacuum space formed by the dewar window, the dewar body and the dewar inner tube seat, and the dewar cold finger is fixed on the dewar inner tube seat in the dewar body. The bottom plate is fixed on the upper end of the Dewar cold finger, the cold screen is fixed on the upper end of the bottom plate, a loading substrate is fixed on the bottom plate inside the cold screen, an infrared chip is fixed on the loading substrate, a filter is installed on the upper end of the cold screen, a throttling refrigerator base is installed in the Dewar cold finger and passes through the Dewar inner tube seat and the throttling refrigerator mounting seat, and a quick-start infrared detector is extended, and a fin tube is wound around the outer wall of the throttling refrigerator base in the Dewar cold finger, wherein: there are micro channels in the loading substrate, one end of the throttling tube passes through the bottom plate and is connected to the micro channel air inlet, and the other end is connected to the upper end of the fin tube, the diameter of the throttling tube is smaller than the diameter of the fin tube, and the micro channel air outlet is opened on the bottom plate in the space surrounded by the bottom plate and the Dewar cold finger.

[0009] The fast-start infrared detector of the present invention, wherein: the loading substrate is a multi-layer ceramic substrate.

[0010] The quick-start infrared detector of the present invention, wherein: the loading substrate is soldered to the bottom plate by soldering material.

[0011] The quick-start infrared detector of the present invention, wherein: the diameter of the micro-channel is 0.1mm-1mm.

[0012] The quick-start infrared detector of the present invention has the following advantages:

[0013] 1. The microchannel technology used in the substrate shortens the cooling distance and greatly reduces the heat transfer resistance. The microchannel increases the residence time of the refrigerant in the substrate and reduces the loss of cooling capacity.

[0014] 2. The brazing connection technology between the bottom plate and the loading substrate ensures the airtightness and reliability of the connection.

[0015] 3. The metal bottom plate opening is connected with the throttling hole of the throttling cooler to ensure machinability and reliability.

[0016] 4. The quick-start infrared detector of the present invention adopts the integrated design of Dewar throttling cooler, which greatly reduces the refrigeration heat transfer thermal resistance of the infrared detector and improves the refrigeration start-up time of the detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a forward cross-section of a quick-start infrared detector of the present invention;

[0018] Figure 2 It is a three-dimensional schematic diagram of the quick-start infrared detector of the present invention.

[0019] exist Figure 1 and Figure 2 Among them, label 1 is an optical window; label 2 is a Dewar window; label 3 is a cold screen; label 4 is an infrared chip; label 5 is a loading substrate; label 6 is a brazing material; label 7 is a bottom plate; label 8 is a Dewar body; label 9 is a microchannel air outlet; label 10 is a microchannel; label 11 is a Dewar cold finger; label 12 is a Dewar inner tube seat; label 13 is a throttling refrigerator mounting seat; label 14 is a throttling refrigerator base; label 15 is a finned tube; label 16 is a microchannel air inlet; label 17 is a filter; label 18 is a throttling tube. DETAILED DESCRIPTION

[0020] like Figure 1 and Figure 2As shown, the quick-start infrared detector of the present invention comprises: a Dewar window 2, a cold shield 3, an infrared chip 4, a loading substrate 5, a bottom plate 7, a Dewar body 8, a Dewar cold finger 11, a Dewar inner tube seat 12, a throttling refrigerator mounting seat 13, a throttling refrigerator base 14, a fin tube 15 and a filter 17, the Dewar inner tube seat 12 is fixed on the throttling refrigerator mounting seat 13, the lower end of the Dewar body 8 is fixed on the Dewar inner tube seat 12, the lower end of the Dewar window 2 is fixed to the upper end of the Dewar body 8, the upper end of the Dewar window 2 is provided with an optical window 1, and the cold shield 3, the infrared chip 4, the loading substrate 5, the bottom plate 7, the Dewar body 8 and the Dewar inner tube seat 12 are installed in the vacuum space formed by the Dewar window 2, the Dewar body 8 and the Dewar inner tube seat 12. The plate 5, the bottom plate 7, the Dewar cold finger 11, the fin tube 15 and the filter 17, the Dewar cold finger 11 is fixed on the Dewar inner tube seat 12 in the Dewar body 8, the bottom plate 7 is fixed on the upper end of the Dewar cold finger 11, the cold shield 3 is fixed on the upper end of the bottom plate 7, the loading substrate 5 is welded on the bottom plate 7 by the brazing material 6, the loading substrate 5 is a multilayer ceramic substrate, the infrared chip 4 is fixed on the loading substrate 5, the filter 17 is installed on the upper end of the cold shield 3, the throttling refrigerator base 14 is installed in the Dewar cold finger 11 and passes through the Dewar inner tube seat 12 and the throttling refrigerator mounting seat 13, and extends out the infrared detector of quick start, and the fin tube 15 is wound on the outer wall of the throttling refrigerator base 14 in the Dewar cold finger 11. There are micro channels 10 all over the loading substrate 5, and the diameter of the micro channels 10 is 0.1mm to 1mm. One end of the throttle tube 18 passes through the bottom plate 7 and is connected to the microchannel air inlet 16, and the other end is connected to the upper end of the fin tube 15. The diameter of the throttle tube 18 is smaller than the diameter of the fin tube 15. The microchannel air outlet 9 is opened on the bottom plate 7 in the space surrounded by the bottom plate 7 and the Dewar cold finger 11.

[0021] The above is only one embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention.

Claims

1. A quick-start infrared detector, comprising: Dewar window (2), cold shield (3), infrared chip (4), loading substrate (5), bottom plate (7), Dewar body (8), Dewar cold finger (11), Dewar inner tube seat (12), throttling refrigerator mounting seat (13), throttling refrigerator base (14), finned tube (15) and filter (17), the Dewar inner tube seat (12) is fixed on the throttling refrigerator mounting seat (13), the lower end of the Dewar body (8) is fixed on the Dewar inner tube seat (12), and the lower end of the Dewar window (2) is fixed on the Dewar inner tube seat (12). The end is fixed to the upper end of the Dewar body (8), an optical window (1) is opened at the upper end of the Dewar window (2), a cold shield (3), an infrared chip (4), a loading substrate (5), a bottom plate (7), a Dewar cold finger (11), a fin tube (15) and a filter (17) are installed in the vacuum space composed of the Dewar window (2), the Dewar body (8) and the Dewar inner tube seat (12), the Dewar cold finger (11) is fixed on the Dewar inner tube seat (12) in the Dewar body (8), and the bottom plate (7) is fixed on the Dewar inner tube seat (12) in the Dewar body (8). The upper end of the Dewar cold finger (11), the cold shield (3) is fixed to the upper end of the bottom plate (7), a loading substrate (5) is fixed on the bottom plate (7) inside the cold shield (3), an infrared chip (4) is fixed on the loading substrate (5), a filter (17) is installed on the upper end of the cold shield (3), a throttling refrigerator base (14) is installed in the Dewar cold finger (11) and passes through the Dewar inner tube seat (12) and the throttling refrigerator mounting seat (13), and a quick-start infrared detector is extended, and a fin tube (15) is wound around the Dewar. The outer wall of the throttling refrigerator base (14) in the Dewar cooling finger (11) is characterized in that: there are micro channels (10) all over the loading substrate (5), one end of the throttling tube (18) passes through the bottom plate (7) and is connected to the micro channel air inlet (16), and the other end is connected to the upper end of the fin tube (15), the diameter of the throttling tube (18) is smaller than the diameter of the fin tube (15), and the micro channel air outlet (9) is opened on the bottom plate (7) in the space surrounded by the bottom plate (7) and the Dewar cooling finger (11).

2. The quick-start infrared detector according to claim 1, characterized in that: The loading substrate (5) is a multi-layer ceramic substrate.

3. The quick-start infrared detector according to claim 2, characterized in that: The loading substrate (5) is welded to the bottom plate (7) via solder (6).

4. The quick-start infrared detector according to claim 3, characterized in that: The diameter of the microchannel (10) is 0.1 mm to 1 mm.

Images