A compact non-vacuum thermoelectric refrigeration device for a spectrometer CCD

Abstract

The utility model belongs to the technical field of refrigeration type spectrometer, and relates to a compact non-vacuum thermoelectric refrigeration device for spectrometer CCD, which comprises the following in sequence along the direction of spectrum incidence: a window heat conduction cover, a window glass plate, a CCD pressing plate, a cavity shell, a heat insulation layer, a CCD detector, a TEC thermoelectric refrigeration piece and a wind cooling fin seat. The window glass plate is arranged in the cylinder of the cavity shell, and blocks the spectrum incidence channel. The window glass plate seals and isolates the cavity shell cylinder towards the rear cylinder opening side to form an independent closed cavity. The refrigeration surface of the TEC thermoelectric refrigeration piece is attached to the CCD detector. The utility model sets the closed space where the CCD detector cavity is located to be small, and uses a small size TEC thermoelectric refrigeration unit in the small space. The closed space is cooled to conduct heat to the external wind cooling fin seat, thereby ensuring the low temperature environment in the closed space. Therefore, the utility model can improve the measurement precision of the refrigeration type spectrometer.

Description

Technical Field

[0001] This utility model belongs to the field of cooling technology for CCD detectors in spectrometers, specifically relating to a compact non-vacuum thermoelectric cooling device for CCD detectors in spectrometers. Background Technology

[0002] With the development of my country's optoelectronic detection instrument industry, the importance of the performance of various spectrometers is increasing day by day. With the development of high-precision CCD (Charge-Coupled Device) detectors, cooling CCD array detectors is an effective means to reduce dark noise, while also increasing the dynamic range and detection limit of the detector.

[0003] Actual observations revealed that if the sensor in the spectrometer is a linear CCD module, when the integration time exceeds 1 second, the CCD becomes submerged in its own dark current. Furthermore, when the CCD junction temperature drops by approximately 25°C, the dark current decreases by almost an order of magnitude. When the CCD array detector is cooled from room temperature (25°C) to 10–14°C using a Thermo-Electric Cooler (TEC), the dark current decreases by four times, and the dark noise decreases by two times. This demonstrates that using TEC cooling enables the detector to perform long integration times and detect weak light.

[0004] This places higher demands on the miniaturization of lower temperature cooling. Furthermore, as the social demand for high-precision spectrometers increases, conventional Dewar refrigeration methods can no longer meet the needs of large-scale production and promotion. Moreover, the addition of a large liquid cooling circulation system during operation greatly inconveniences users and limits the application environment and scope of use.

[0005] In the use of cryogenic cavity CCD modules, the cryogenic characteristics cause moisture in the air to condense inside the CCD detector cavity, forming frost, dew, and fog on the inner and outer surfaces of the window glass. This phenomenon significantly alters the surface emissivity of the cavity glass and produces medium absorption, resulting in a significant reduction in the effective emissivity at the bottom of the cavity. This becomes a major source of uncertainty, obstructing observations by various types of cooled spectrometers and thus affecting their measurement accuracy.

[0006] Currently, three methods are generally used for semiconductor thermoelectric cooling applications in CCD detectors:

[0007] 1. It adopts a Dewar-type vacuum chamber, whose vacuum and multi-layer shell structure reduce internal air convection heat conduction, and the temperature can be reduced by 50-70°C by using multi-stage TEC cooling. However, this requires a high-vacuum Dewar sealed chamber and air extraction structure, as well as a large-size flange and sealing surface structure. Its chamber structure is relatively large, and the window size is also large. The large window can minimize condensation in the center of the lens. However, pressure difference may lead to leakage at individual sealing points, which cannot guarantee the long-term reliability of the seal. This makes it unsuitable for use in general small-sized spectrometers and is mostly used in astronomical observation, high-speed photography, and large high-definition cameras.

[0008] 2. A pressure-resistant cavity filled with nitrogen is used, typically equipped with a gas purging system to purge and heat the window glass surface, bringing it closer to room temperature. This reduces the temperature difference and significantly decreases condensation. However, this requires a larger window size and a gas filling device. Some systems also require canned nitrogen or an air compressor to provide the dry gas, and the air curtain structure is complex. Furthermore, while nitrogen is more stable, its larger intermolecular spacing results in a higher thermal conductivity than dry air, making its thermal efficiency actually higher than that of air.

[0009] 3. Array CCDs that directly adopt integrated cooling functions (such as Hamamatsu S7031-1006S) have a TEC unit integrated at the bottom inside. They only need to be equipped with heat sinks or forced cooling heat sinks to be used. However, their prices are very high, which greatly limits the promotion and application of high-precision spectrometers.

[0010] Therefore, there is a need for a miniaturized, simple, reliable, and low-cost device or method capable of providing general-level cooling for CCD detectors to solve the aforementioned technical problems. Utility Model Content

[0011] To solve the aforementioned technical problems, this invention features a very small sealed cavity and employs a single-stage, small-sized TEC thermoelectric cooling unit. The hot side connects to the rear heat sink fins, while the cold side is attached to the bottom surface of a standard CCD. Signal acquisition is transmitted to an external circuit board using a combination of long pins and a syringe, with the pins reliably sealed with potting sealant. This results in a cavity space typically less than 60mm. A small amount of annular gas inside is dried by a pre-placed desiccant, requiring very little desiccant, and the dry air will not condense on the inner surface of the window glass under any pressure. To prevent condensation on the outer surface of the window glass from contacting moisture-containing ambient gases, this invention adds a heat-conducting cover to the outside of the glass, transferring heat from the TEC hot end of the rear heat sink to the outside. Additionally, a certain distance is maintained between the CCD and the glass to create significant thermal resistance. When the internal air temperature differs from the ambient temperature by 9–10°C, condensation is completely eliminated, thus eradicating frost and condensation. Furthermore, this invention is simple, reliable, and perfectly suited for installation in typical small spectrometers.

[0012] This utility model provides the following technical solution: a compact non-vacuum thermoelectric cooling device for a spectrometer CCD, comprising: arranged sequentially along the incident direction of the spectrum: a window heat-conducting cover, a window glass plate, a CCD pressure plate, a cavity shell, a heat insulation layer, a CCD detector, a TEC thermoelectric cooling chip, and an air-cooled fin holder, wherein the window heat-conducting cover and the air-cooled fin holder are respectively made of heat-conducting materials, and the CCD pressure plate, the cavity shell, and the heat insulation layer are respectively made of heat-insulating materials;

[0013] The outer shell of the cavity is cylindrical with openings at the front and back. The rear opening of the outer shell is sealed and connected to the air-cooled fin seat. The front opening of the outer shell is detachably connected to the window heat-conducting cover. The window heat-conducting cover is heat-conductingly connected to the air-cooled fin seat.

[0014] The window glass plate is set inside the outer shell of the cavity, blocking the spectral incident channel and sealing the inner side of the outer shell towards the rear opening into an independent sealed cavity. The CCD pressure plate is attached to the side of the window glass plate located in the sealed cavity, and the side of the CCD pressure plate away from the window glass plate is pressed against the detection surface of the CCD detector. The cooling surface of the TEC thermoelectric cooler is attached to the CCD detector, and the heat dissipation surface of the TEC thermoelectric cooler is thermally connected to the air-cooled fin seat. The inner wall of the heat insulation layer is wrapped around the sealed cavity, and the outer wall of the heat insulation layer is attached to the inner wall of the outer shell of the cavity.

[0015] Preferably, the sealed cavity is provided with a drying sheet and / or a desiccant module.

[0016] More preferably, the desiccant module includes a left desiccant module and a right desiccant module, which are respectively arranged on the left and right sides of the sealed cavity.

[0017] Preferably, a CCD insertion board is provided inside the sealed cavity, and an insertion syringe is provided on the CCD insertion board; the pins of the CCD detector are electrically connected to the insertion syringe, and the CCD insertion board is electrically connected to the adapter circuit board through a pin header.

[0018] More preferably, both the CCD plug-in board and the adapter circuit board are C-shaped circuit boards with an opening on one side, and the C-shaped openings of the CCD plug-in board and the adapter circuit board are located on the same side.

[0019] Preferably, a sealing gasket made of heat-insulating material is provided between the cavity shell and the air-cooled fin seat.

[0020] More preferably, the sealing gasket is annular, and grooves are respectively provided on the inner bottom surface of the air-cooled fin seat and the inner cylinder end face of the cavity shell, and the sealing gasket matches the grooves; the inner bottom surface of the air-cooled fin seat and the inner cylinder end face of the cavity shell clamp the sealing gasket inside.

[0021] Preferably, the joint between the window glass and the inner wall of the cavity shell is filled with sealant.

[0022] The beneficial effects of this utility model are:

[0023] 1. This invention reduces the size of the enclosed space containing the CCD detector cavity and uses a small-sized TEC thermoelectric cooling unit within the small space to cool the enclosed space and transfer the heat to the external air-cooled fin mount, thereby ensuring a low-temperature environment within the enclosed space. Therefore, this invention can improve the measurement accuracy of the cooled spectrometer.

[0024] 2. This utility model connects the window heat-conducting cover with the air-cooled fin seat in a heat-conducting manner, so that the heat of the air-cooled fin seat is conducted to the outside of the window glass plate, so that no condensation occurs on the outside of the window glass plate, thereby completely eliminating the phenomenon of frost and condensation. Therefore, this utility model can improve the measurement accuracy of the cooling spectrometer.

[0025] 3. By placing a desiccant in a sealed space, this invention requires very little desiccant due to the small size of the sealed space, thus preventing frost and condensation from forming on the inside of the window glass. Therefore, this invention can improve the measurement accuracy of the cooled spectrometer. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of a compact non-vacuum thermoelectric refrigeration device for a spectrometer CCD according to the present invention.

[0027] Figure 2 This is a schematic diagram of the installation position structure of this utility model;

[0028] Figure 3This is a three-dimensional schematic diagram of the overall structure of the refrigeration module of this utility model;

[0029] Figure 4 This is an exploded disassembly diagram of the overall structure of the refrigeration module of this utility model;

[0030] Figure 5 This is a longitudinal sectional view of the refrigeration module structure of this utility model;

[0031] Figure 6 This is a cross-sectional view of the refrigeration module structure of this utility model;

[0032] Figure 7 This is a schematic diagram of the structure of the CCD connector board of this utility model;

[0033] Figure 8 This is a schematic diagram of the structure of the adapter circuit board of this utility model;

[0034] Figure 9 This is a schematic diagram illustrating the monitoring accuracy in an embodiment of this utility model.

[0035] In the diagram, 1 is the cooling unit; 2 is the cooling fan; 3 is the spectrometer housing; 4 is the spectrometer base plate; 101 is the window heat conduction cover; 102 is the CCD pressure plate; 103 is the drying plate; 104 is the window glass plate; 105 is the cavity housing; 106 is the heat insulation layer; 107 is the CCD detector; 108 is the TEC thermoelectric cooling chip; 109 is the CCD connector board; 110 is the left desiccant module; 111 is the right desiccant module; 112 is the pin header; 113 is the sealing gasket; 114 is the adapter circuit board; 115 is the air-cooled fin holder; 116 is the sealant; and 301 is the connector cylinder. Detailed Implementation

[0036] The relevant technologies of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0037] like Figures 1-9 As shown, this embodiment provides a miniaturized, simple, reliable, and low-cost technique for cooling CCD detectors. This embodiment makes it possible to widely promote and apply high-precision spectrometers in various scientific research and testing fields.

[0038] Figure 1 , 2The figure shows the shape and structure of a small high-precision spectrometer. The entire cooling device 1 is installed on the spectrometer housing 3 and aligned with the spectrometer's spectral emission outlet to receive spectral signals from the window. A cooling fan 2 is fixed on the spectrometer housing 3 and is aligned with the cooling fin seat 115 of the cooling device 1 for forced convection cooling.

[0039] like Figure 3 , 4 As shown, the cooling device 1 includes a window heat-conducting cover 101, a CCD pressure plate 102, a drying plate 103, a window glass plate 104, a cavity shell 105, a heat insulation layer 106, a CCD detector 107, a TEC thermoelectric cooling chip 108, a CCD plug-in board 109, a left desiccant module 110, a right desiccant module 111, a pin header 112, a sealing gasket 113, a converter circuit board 114, an air-cooled fin holder 115, and a sealant 116, and a connector syringe 301; the window heat-conducting cover 101, the CCD pressure plate 102, the window glass plate 103, the window glass plate 104, ... window heat-conducting cover 102, the window glass plate 103, the window glass plate 104, the window heat-conducting cover 105, the window glass plate 106, the window glass plate 107, the window heat-conducting cover 108, the window heat-conducting cover 109, the window heat-conducting cover 100, the window heat-conducting cover 101, the window heat-conducting cover 102, the window glass plate 103, the window heat-conducting cover 104, the window heat The glass plate 104, the outer shell of the cavity 105, the heat insulation layer 106, the CCD detector 107, the TEC thermoelectric cooler 108, and the air-cooled fin holder 115 constitute the cooling cavity unit. Inside, the drying plate 103, the left desiccant module 110, and the right desiccant module 111 constitute the water absorption unit. The CCD connector board 109, the pin header 112, the sealing potting compound 116, and the adapter circuit board 114 constitute the circuit transmission unit. The entire unit is housed within the external spectrometer housing 3 and can be fitted with a fan 2 to force convection cooling of the air-cooled fins 115, ensuring efficient heat dissipation at the heat-generating end of the TEC cooler. For detailed descriptions of each part and component, please refer to Table 1.

[0040] like Figure 5 , Figure 6 As shown, the uniqueness and difference of the refrigeration device 1 are mainly in the following aspects:

[0041] Anti-condensation method for windows: The interior uses a desiccant sheet 103 (calcium chloride) and desiccant modules 110 and 111 (water-absorbing silica gel powder packs) to maximize the absorption of water in the small space; the exterior is made of a cover made of high thermal conductivity ceramic material or copper-aluminum material, with windows. Heat is conducted from the air-cooled fin seat 115 to the outer surface of the window glass plate 104, heating it to a certain extent to offset the heat absorbed by the CCD from internal cooling. At the same time, the cavity shell 105 is made of low thermal conductivity engineering plastic so that the internal cooling force is not affected by the outside, thereby balancing the temperature difference between the inner and outer surfaces of the window glass plate 104.

[0042] Sealing methods for small modules: For the seal between the window glass panel 104 and the cavity housing 105, an annular groove is cut into the sealing surface of the cavity housing 105, and sealant (including but not limited to epoxy, single-component or multi-component silicone) is poured into it. For the seal between the cavity housing 105 and the air-cooled fin seat 115, a sealing gasket 113 is installed in the inner plane of the groove on the bottom surface of the air-cooled fin seat 115, and the annular rib inside the cavity housing 105 is used for compression sealing. For the seal of the wire guide pins 112 at the bottom of the air-cooled fin seat 115, a shallow groove is cut into the bottom of the air-cooled fin seat 115, and a corresponding pin through hole is drilled at the bottom of the groove. After the pins are installed, they are sealed with sealant (including but not limited to epoxy, single-component or multi-component silicone). These sealing methods are all effective, occupy a small size, and are reliable over a long period of time.

[0043] Regarding the plug-in method for circuit connections: such as Figure 7 and Figure 8 The CCD connector board 109 is connected to the adapter circuit board 114 via a double-headed long pin array 112, reliably transmitting CCD electrical signals from the cavity. The double-headed long pin array 112 is disposed within the sealed cavity formed by the cavity housing 105 and the air-cooled fin holder 115. The connector units on each board are composed of an array of multiple syringes 301. The C-shaped opening on the CCD connector board 109 is used to assemble and surround the CCD boss, and the C-shaped opening on the adapter circuit board 114 is used to assemble and surround the neck groove in the middle of the outer side of the air-cooled fin holder 115. After the double-headed long pin array 112 is fixed with glue, it becomes very convenient to install the pins of the CCD 107 and align the syringe 301 array holder of the adapter circuit board 114 during production. Table 1 shows the components and related descriptions in this embodiment.

[0044] Table 1

[0045]

[0046]

[0047]

[0048]

[0049] Example

[0050] In this embodiment, a compact non-vacuum thermoelectric cooling device for the spectrometer CCD is applied to a power transformer. After installation, a specially designed drive power board is used to cool the large power transformer in a large power transmission and transformation station. The cooling system automatically starts upon power-on, with a target temperature of 1°C. After algorithm optimization, the temperature control drift stabilizes within ±0.1°C, fully achieving the temperature control target. With a 15-second integration time, the temperature control significantly suppresses spectrometer noise fluctuations, fully meeting the equipment testing accuracy standards proposed by the company.

[0051] In summary, this invention reduces the size of the enclosed space containing the CCD detector cavity and uses a small-sized TEC thermoelectric cooling unit within that space to cool the enclosed space and transfer the heat to the external air-cooled fin mount, thereby ensuring a low-temperature environment within the enclosed space. Therefore, this invention can improve the measurement accuracy of the cooled spectrometer.

[0052] It should be emphasized that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A compact non-vacuum thermoelectric cooling device for a spectrometer CCD, characterized in that, include: The following components are arranged sequentially along the incident spectral direction: a window heat-conducting cover (101), a window glass plate (104), a CCD pressure plate (102), a cavity shell (105), a heat insulation layer (106), a CCD detector (107), a TEC thermoelectric cooling chip (108), and an air-cooled fin holder (115). The window heat-conducting cover (101) and the air-cooled fin holder (115) are made of heat-conducting materials, and the CCD pressure plate (102), the cavity shell (105), and the heat insulation layer (106) are made of heat-insulating materials. The cavity shell (105) is cylindrical with openings at the front and rear. The rear opening of the cavity shell (105) is sealed and connected to the air-cooled fin seat (115). The front opening of the cavity shell (105) is detachably connected to the window heat-conducting cover (101). The window heat-conducting cover (101) is thermally connected to the air-cooled fin seat (115). The window glass plate (104) is disposed inside the cylinder of the cavity shell (105). The window glass plate (104) blocks the spectral incident channel and seals the inside of the cavity shell (105) towards the rear opening as an independent sealed cavity. The CCD pressure plate (102) is attached to the side of the window glass plate (104) located in the sealed cavity, and the side of the CCD pressure plate (102) away from the window glass plate (104) is pressed against the detection surface of the CCD detector (107). The cooling surface of the TEC thermoelectric cooler (108) is attached to the CCD detector (107), and the heat dissipation surface of the TEC thermoelectric cooler (108) is thermally connected to the air-cooled fin seat (115). The inner wall of the heat insulation layer (106) wraps around the sealed cavity, and the outer wall of the heat insulation layer (106) is attached to the inner wall of the cavity shell (105). The sealed cavity is provided with a drying plate (103) and / or a desiccant module; the desiccant module includes: a left desiccant module (110) and a right desiccant module (111), the left desiccant module (110) and the right desiccant module (111) are respectively arranged on the left and right sides of the sealed cavity; The joint between the window glass panel (104) and the inner wall of the cavity shell (105) is filled with sealant (116).

2. A compact non-vacuum thermoelectric cooling device for a spectrometer CCD according to claim 1, characterized in that, The sealed cavity is provided with a CCD connector plate (109), and the CCD connector plate (109) is provided with a connector syringe (301); the pins of the CCD detector (107) are electrically connected to the connector syringe (301), and the CCD connector plate (109) is electrically connected to the adapter circuit board (114) through the pin header (112).

3. A compact non-vacuum thermoelectric cooling device for a spectrometer CCD according to claim 2, characterized in that, The CCD plug-in board (109) and the adapter circuit board (114) are both C-shaped circuit boards with openings on one side, and the C-shaped openings of the CCD plug-in board (109) and the adapter circuit board (114) are located on the same side.

4. A compact non-vacuum thermoelectric cooling device for a spectrometer CCD according to claim 1, characterized in that, A sealing gasket (113) made of heat-insulating material is provided between the cavity shell (105) and the air-cooled fin seat (115).

5. A compact non-vacuum thermoelectric cooling device for a spectrometer CCD according to claim 4, characterized in that, The sealing gasket (113) is annular. The bottom surface of the air-cooled fin seat (115) and the end face of the inner cylinder of the cavity shell (105) are respectively provided with grooves. The sealing gasket (113) matches the grooves. The bottom surface of the air-cooled fin seat (115) and the end face of the inner cylinder of the cavity shell (105) clamp the sealing gasket (113) inside.

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