Infrared thermal imager

Abstract

The utility model discloses an infrared thermal imager which comprises a metal packaging shell, a TEC refrigeration sheet, an infrared chip, an optical window assembly, an electric connection assembly and a plurality of wires, the optical window assembly is connected with the metal packaging shell so as to define a vacuum cavity with the metal packaging shell, one end of the electric connection assembly is arranged in the vacuum cavity, and the other end of the electric connection assembly is arranged in the metal packaging shell. One end of the TEC refrigeration sheet is connected with the metal packaging shell, the other end of the TEC refrigeration sheet penetrates through the metal packaging shell and is exposed out of the metal packaging shell, the TEC refrigeration sheet is connected with the metal packaging shell so as to be fixed in the vacuum cavity, the infrared chip is installed on the side, facing the optical window assembly, of the TEC refrigeration sheet, the TEC refrigeration sheet is provided with a first metal bonding pad, and the infrared chip is provided with a second metal bonding pad. The first metal bonding pad is communicated with the electric connection assembly through the corresponding wire, and the second metal bonding pad is communicated with the electric connection assembly through the corresponding wire. According to the utility model, the problems of soldering flux residue and oxidation caused by soldering iron welding process are avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of infrared thermal imaging, in particular to an infrared thermal imager. Background Art

[0002] In the infrared thermal imaging packaging industry, the power lines of semiconductor cooling devices (TECs) are usually soldered using flux such as solder paste or solder wire to ensure the quality of the connection. However, this soldering method has the risk of residual flux, which may affect the vacuum degree of the internal cavity of the infrared thermal imaging package due to volatilization over time, thereby adversely affecting the service life of the infrared imaging component.

[0003] In addition, when soldering the TEC leads at the customer end, in order to avoid problems caused by flux, flux-free solder wire must be used. However, the flux-free soldering process will cause the solder joint area to be easily oxidized. Utility Model Content

[0004] The technical problem to be solved by the utility model is that during the conventional welding of TEC power leads, the residual flux may affect the service life of the infrared imaging component due to volatilization and cause oxidation problems during welding.

[0005] In order to solve the above technical problems, the utility model provides an infrared thermal imager, including a metal packaging shell, a TEC cooling sheet, an infrared chip, an optical window component, an electrical connection component and a plurality of wires, wherein the optical window component is connected to the metal packaging shell to enclose the metal packaging shell to form a vacuum cavity, one end of the electrical connection component is arranged in the vacuum cavity, and the other end passes through the metal packaging shell and is exposed outside the metal packaging shell, the TEC cooling sheet is connected to the metal packaging shell to be fixed in the vacuum cavity, the infrared chip is installed on the side of the TEC cooling sheet facing the optical window component, the TEC cooling sheet has a first metal pad, and the infrared chip has a second metal pad, the first metal pad is connected to the electrical connection component through the corresponding wire, and the second metal pad is connected to the electrical connection component through the corresponding wire.

[0006] In some embodiments, the TEC cooling sheet includes a first ceramic substrate, particles and a second ceramic substrate, the particles are welded between the first ceramic substrate and the second ceramic substrate, the first metal pad is arranged on the side of the second ceramic substrate away from the first ceramic substrate, and the first ceramic substrate is connected to the metal packaging shell.

[0007] In some embodiments, the first metal pad includes a positive electrode pad and a negative electrode pad, and the positive electrode pad and the negative electrode pad are respectively located on two opposite sides of the second ceramic substrate.

[0008] In some embodiments, the particles are made of bismuth telluride alloy material.

[0009] In some embodiments, a silver paste layer is disposed between the TEC cooling sheet and the infrared chip.

[0010] In some embodiments, the electrical connection component includes multiple pins, one end of the pins is arranged in the vacuum chamber, and the other end passes through the metal packaging shell and is exposed outside the metal packaging shell, and each of the pins is connected to the first metal pad and the second metal pad respectively through the corresponding wire.

[0011] In some embodiments, ceramic is filled between adjacent pins.

[0012] In some embodiments, the optical window assembly includes an optical window germanium sheet and a metal layer, and the metal layer is plated on the surface of the optical window germanium sheet.

[0013] In some embodiments, a first solder sheet and a second solder sheet are further included, wherein the TEC cooling sheet is connected to the metal packaging shell via the first solder sheet, and the optical window assembly is connected to the metal packaging shell via the second solder sheet.

[0014] In some embodiments, a getter is also included, and the getter is disposed in the vacuum chamber.

[0015] Compared with the prior art, the infrared thermal imager of the present utility model has the following beneficial effects:

[0016] The embodiment of the utility model connects the first metal pad with the electrical connection component through a wire, and connects the second metal pad with the electrical connection component through a wire, and can use automated welding to improve automatic welding. At the same time, the connection between the TEC cooling plate and the metal packaging shell is changed from the original soldering iron welding wire to the WB process connection method, thereby realizing automation and improving production efficiency, and at the same time, it can also avoid residual flux and oxidation problems caused by the soldering iron welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a top view of the infrared thermal imager provided by the embodiment of the utility model without the optical window assembly;

[0018] Figure 2 It is a schematic diagram of an explosion of an infrared thermal imager provided by an embodiment of the utility model;

[0019] In the figure, 1. metal packaging shell; 11. main body; 12. fixing part; 121. mounting hole; 2. TEC cooling plate; 21. first metal pad; 211. positive pad; 212. negative pad; 3. infrared chip; 31. second metal pad; 4. optical window assembly; 41. optical window germanium sheet; 5. electrical connection assembly; 51. pin; 6. wire; 7. first solder sheet; 8. second solder sheet; 9. getter. DETAILED DESCRIPTION

[0020] The following is a further detailed description of the specific implementation of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0021] like Figure 1 As shown, the utility model provides an infrared thermal imager, including a metal packaging shell 1, a TEC cooling sheet 2, an infrared chip 3, an optical window component 4, an electrical connection component 5 and a plurality of wires 6. The metal packaging shell 1, as the basic frame of the device, not only provides physical protection for the internal components, but also the optical window component 4 is connected to the metal packaging shell 1 to enclose the metal packaging shell 1 to form a vacuum cavity, so as to minimize the influence of heat conduction and atmospheric absorption on infrared radiation, thereby improving the detection sensitivity and image quality of the infrared chip 3. The infrared chip 3, as the main core component, mainly receives external infrared radiation signals and converts them into electrical signals for output. The TEC cooling sheet 2 is connected to the metal packaging shell 1 to be fixed in the vacuum cavity. The infrared chip 3 is installed on the side of the TEC cooling sheet 2 facing the optical window component 4, so as to maintain its operation at a lower temperature through cooling by the TEC cooling sheet 2, so as to ensure that the infrared chip 3 can accurately capture weak infrared signals and avoid interference caused by self-heating; the optical window component 4 is used to allow infrared radiation to pass through into or out of the vacuum cavity, and at the same time protect the internal infrared chip 3. One end of the electrical connection component 5 is arranged in the vacuum cavity, and the other end passes through the metal packaging shell 1 and is exposed outside the metal packaging shell 1. The TEC cooling sheet 2 has a first metal pad 21, and the infrared chip 3 has a second metal pad 31. The first metal pad 21 is connected to the electrical connection component 5 through a corresponding wire 6, and the second metal pad 31 is connected to the electrical connection component 5 through a corresponding wire 6, so as to be electrically connected to an external power supply, a control circuit, etc., to transmit the necessary voltage and current to drive the TEC cooling and read the electrical signal output by the infrared chip 3.

[0022] Based on the above structure, the packaging connection between the TEC cooling plate 2 and the infrared chip 3 can adopt the WB (Wire Bonding) process, and the first metal pad 21 is connected to the electrical connection component 5 through the wire 6, and the second metal pad 31 is connected to the electrical connection component 5 through the wire 6. Automatic welding can be used to improve automatic welding. At the same time, the connection between the TEC cooling plate 2 and the metal packaging shell 1 is changed from the original soldering iron welding wire to the WB process connection method, thereby realizing automation and improving production efficiency. At the same time, it can also avoid residual flux and oxidation problems caused by the soldering iron welding process.

[0023] Read also Figure 2 In some embodiments, the metal package shell 1 is mainly composed of a J4J2 alloy, and is formed by electroplating Ni and Au on its surface. The main function is to provide a highly airtight vacuum cavity to isolate the infrared chip 3 from the atmosphere. The metal package shell 1 in this embodiment includes a main body 11 and a fixing portion 12. The fixing portion 12 is arranged on the side of the main body 11 away from the optical window assembly 4, and a plurality of mounting holes 121 are provided on the fixing portion for fixed installation; the main body 11 is formed with an empty groove to connect with the optical window assembly 4 and enclose a vacuum cavity.

[0024] In actual application, the main material of the wire 6 is Au, Ag, Al or Cu. In this embodiment, the wire 6 is preferably made of Au material.

[0025] In some embodiments, the TEC cooling sheet 2 includes a first ceramic substrate, particles and a second ceramic substrate, the particles are welded between the first ceramic substrate and the second ceramic substrate, the first metal pad 21 is arranged on the side of the second ceramic substrate away from the first ceramic substrate, and the first ceramic substrate is connected to the metal packaging shell 1.

[0026] The particles of this embodiment are welded between the first ceramic substrate and the second ceramic substrate, and the Peltier effect is used to generate heat absorption and release on both sides when current passes through, thereby achieving a cooling effect. In addition, the circuit part of the TEC cooling sheet 2 is electrically connected to an external power supply or control system through the first metal pad 21, so as to provide the TEC cooling sheet 2 with the current required for operation.

[0027] In some embodiments, the first metal pad 21 includes a positive pad 211 and a negative pad 212, and the positive pad 211 and the negative pad 212 correspond to the current inflow end and the current outflow end of the TEC cooling sheet 2 when it is working, respectively. They are electrically connected to the external power supply, control system, etc. through the wire 6 to form a complete closed loop, so that the current can flow inside the semiconductor element and use the Peltier effect to perform thermoelectric conversion. In addition, the positive pad 211 and the negative pad 212 are respectively located on the opposite sides of the second ceramic substrate, which reduces the power line welding process, is conducive to simplifying the assembly process, and ensures that the wiring operation can be conveniently performed when installed in an infrared thermal imager or other application equipment, and is convenient for better management and control of the heat distribution of the cooling surface and the heating surface, thereby improving the cooling efficiency and the overall performance of the device.

[0028] Preferably, the particles are made of bismuth telluride alloy material. The good thermoelectric properties of bismuth telluride alloy can effectively improve the working efficiency and stability of the TEC cooling plate 2.

[0029] In some embodiments, a silver paste layer is disposed between the TEC cooling sheet 2 and the infrared chip 3 .

[0030] It can be understood that the silver paste layer is mainly used as a thermal interface material, and has extremely high thermal conductivity, which can effectively reduce the contact thermal resistance between the TEC cooling sheet 2 and the infrared chip 3, so that the cooling effect generated by the TEC cooling sheet 2 can be quickly transferred to the infrared chip 3, ensuring that the infrared chip 3 works in a suitable low-temperature environment, thereby improving its detection sensitivity and image quality. In addition, the silver paste layer also plays a certain mechanical fixing and supporting role. It can fill the tiny gap that may exist between the TEC cooling sheet 2 and the infrared chip 3, ensuring that the two are tightly combined, and avoiding the reduction of heat dissipation efficiency or device failure due to poor physical contact.

[0031] In some embodiments, the electrical connection component 5 includes multiple pins 51, one end of the pin 51 is arranged in the vacuum chamber, and each pin 51 located in the vacuum chamber is connected to the first metal pad 21 and the second metal pad 31 through the corresponding wire 6, thereby ensuring the integrity and accurate transmission of the electrical signal; the other end of the pin 51 passes through the metal packaging shell 1 and is exposed outside the metal packaging shell 1, and is used to be electrically connected to an external power supply, a control circuit, etc., to transmit the necessary voltage and current to drive the TEC cooling and read the electrical signal output by the infrared chip 3, to ensure that the TEC cooling sheet 2 and the infrared chip 3 can receive the necessary control signals and working currents from the external control system, and at the same time transmit the generated electrical signals back to the external reading system for processing and display.

[0032] In addition, through the cooperation between the metal packaging shell 1 and the optical window assembly 4, the pin 51 realizes effective isolation between the internal and external environments, protecting the internal precision electronic components to reduce the impact of external environmental factors.

[0033] Understandably, Figure 1 The wire 6 shown is only a partial illustration and does not refer to only Figure 1 The number of connections shown is shown in FIG.

[0034] In some embodiments, ceramic is filled between adjacent pins 51 .

[0035] It can be understood that ceramic materials have excellent electrical insulation properties, and filling between adjacent pins 51 can effectively prevent electrical short circuits between different pins 51, ensure the accuracy and independence of signal transmission between each pin 51, and thus ensure the stable operation of the entire circuit system. In addition, ceramic fillers can also fill the gaps between the pins 51 to prevent dust or other contaminants from entering, and at the same time can play a certain role in enhancing structural stability, providing necessary mechanical support, preventing the pins 51 from contacting or moving each other when subjected to external force or vibration, and maintaining the tightness and firmness of the internal structure of the device.

[0036] In some embodiments, the optical window assembly 4 includes an optical window germanium sheet 41 and a metal layer. The optical window germanium sheet 41 in this embodiment is intended to allow infrared radiation to pass through and enter or leave the vacuum cavity inside the infrared thermal imager, ensuring that the infrared signal can be effectively received or sent by the infrared chip 3, thereby achieving accurate detection and conversion of the temperature information of the target object. The surface edge of the optical window germanium sheet 41 is plated with a metal layer to prevent the edge from affecting its optical performance due to wear, so as to improve the mechanical properties of the optical window germanium sheet 41.

[0037] In some embodiments, a first solder sheet 7 is also included, and the TEC refrigeration sheet 2 is connected to the metal packaging shell 1 through the first solder sheet 7. The second solder sheet 8 plays a role of mechanical fixing and sealing, ensuring that the TEC refrigeration sheet 2 is fixed on the metal packaging shell 1 while transferring heat to the outside of the metal packaging shell 1. A second solder sheet 8 is provided between the optical window assembly 4 and the metal packaging shell 1. It can be understood that the first ceramic substrate is connected to the metal packaging shell 1 through the first solder sheet 7, and the first solder sheet 7 is used to connect the first ceramic substrate and the metal packaging shell 1. The welding technology ensures that the TEC refrigeration sheet 2 can be firmly installed in the vacuum chamber of the infrared thermal imager, and a good heat conduction path is achieved, so that the heat generated by the TEC refrigeration sheet 2 can be effectively transferred from the cooling area to the heat dissipation area, and the effective cooling performance of the cooling surface is maintained.

[0038] In this embodiment, a second solder sheet 8 is also included. The optical window assembly 4 is connected to the metal package shell 1 through the second solder sheet 8. The second solder sheet 8 plays a role of mechanical fixing and sealing, ensuring that the optical window assembly 4 is firmly mounted on the metal package shell 1, preventing external environmental pollutants such as moisture, dust, etc. from entering the vacuum cavity, thereby protecting the internal sensitive infrared chip 3 and other electronic components from damage. At the same time, the second solder sheet 8 can also help transfer and disperse heat, especially when the optical window assembly 4 generates heat due to absorbing infrared radiation, part of the heat can be transferred to the metal package shell 1 through the second solder sheet 8, thereby facilitating the heat dissipation management of the entire system.

[0039] In some embodiments, a getter 9 is also included and disposed in the vacuum chamber.

[0040] The getter 9 in this embodiment is used to absorb residual gas molecules inside the vacuum cavity to maintain or improve the vacuum degree of the vacuum system. By effectively reducing the concentration of gas molecules in the vacuum cavity, the getter 9 helps to maintain the consistency of working conditions of the infrared chip 3 and other circuit components, thereby ensuring the quality and accuracy of the image output by the thermal imaging system.

[0041] In summary, the embodiment of the utility model provides an infrared thermal imager, which connects the first metal pad 21 with the electrical connection component 5 through the wire 6, and connects the second metal pad 31 with the electrical connection component 5 through the wire 6. Automatic welding can be used to improve automatic welding. At the same time, the connection between the TEC cooling plate 2 and the metal packaging shell 1 is changed from the original soldering iron welding wire to the WB process connection method, thereby realizing automation and improving production efficiency. At the same time, it can also avoid the residual flux and oxidation problems caused by the soldering iron welding process.

[0042] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principle of the present invention. These improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. An infrared thermal imager, characterized in that: It includes a metal packaging shell, a TEC cooling sheet, an infrared chip, an optical window component, an electrical connection component and multiple wires. The optical window component is connected to the metal packaging shell to enclose the metal packaging shell to form a vacuum cavity. One end of the electrical connection component is arranged in the vacuum cavity, and the other end passes through the metal packaging shell to be exposed outside the metal packaging shell. The TEC cooling sheet is connected to the metal packaging shell to be fixed in the vacuum cavity. The infrared chip is installed on the side of the TEC cooling sheet facing the optical window component. The TEC cooling sheet has a first metal pad, and the infrared chip has a second metal pad. The first metal pad is connected to the electrical connection component through the corresponding wire, and the second metal pad is connected to the electrical connection component through the corresponding wire.

2. The infrared thermal imager according to claim 1, characterized in that: The TEC cooling sheet includes a first ceramic substrate, particles and a second ceramic substrate, the particles are welded between the first ceramic substrate and the second ceramic substrate, the first metal pad is arranged on the side of the second ceramic substrate away from the first ceramic substrate, and the first ceramic substrate is connected to the metal packaging shell.

3. The infrared thermal imager according to claim 2, characterized in that: The first metal pad includes a positive pad and a negative pad, and the positive pad and the negative pad are respectively located on two opposite sides of the second ceramic substrate.

4. The infrared thermal imager according to claim 2, characterized in that: The particles are made of bismuth telluride alloy material.

5. The infrared thermal imager according to claim 1, characterized in that: A silver paste layer is arranged between the TEC cooling sheet and the infrared chip.

6. The infrared thermal imager according to claim 1, characterized in that: The electrical connection component includes a plurality of pins, one end of which is disposed in the vacuum chamber, and the other end of which passes through the metal packaging shell and is exposed outside the metal packaging shell. Each of the pins is connected to the first metal pad and the second metal pad respectively through the corresponding wire.

7. The infrared thermal imager according to claim 6, characterized in that: The space between the adjacent pins is filled with ceramic.

8. The infrared thermal imager according to claim 1, characterized in that: The optical window component comprises an optical window germanium sheet and a metal layer, and the metal layer is plated on the surface of the optical window germanium sheet.

9. The infrared thermal imager according to claim 1, characterized in that: It also includes a first solder sheet and a second solder sheet. The TEC cooling sheet is connected to the metal packaging shell through the first solder sheet, and the optical window assembly is connected to the metal packaging shell through the second solder sheet.

10. The infrared thermal imager according to claim 1, characterized in that: It also includes a getter, which is arranged in the vacuum chamber.

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