A compact focal plane electric box multi-circuit board device heat dissipation and heat preservation system

Abstract

The application relates to a compact focal plane electric box multi-circuit board device heat dissipation and heat preservation system, which comprises a heat conduction plate, L-shaped heat conduction strips, -Y side heat conduction bridges, +Y side heat conduction bridges, an electric heater, a thermistor, a shielding sheet and a semi-enclosed frame, the heat conduction plate is installed on the frame in the focal plane electric box after crossing the gap between the PCBs, the two ends of the L-shaped heat conduction strips are connected with the heat conduction plate and the devices installed on the back of the PCBs respectively; the two heat conduction bridges are installed on the two sides of the heat conduction plate respectively; the focal plane electric box is placed in the semi-enclosed frame, the gap is shielded by the shielding sheet, the outer surface of the shielding sheet and the frame is covered with multiple heat insulation components; the electric heater and the temperature sensor are attached to the outer surface of the semi-enclosed frame. The high-power electronic components on the multiple circuit boards are combined and heat-conducted through the built-in integrated heat conduction channel, the space occupation is greatly reduced, and the heat preservation effect of the devices in the focal plane electric box and the auxiliary heat dissipation effect are realized through the radiation heat preservation device.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft thermal control technology, specifically a comprehensive system that combines heat dissipation and heat preservation functions for multi-circuit board devices in a compact focal plane electrical box. Background Technology

[0002] With the widespread application of small space cameras, focal plane electrical boxes are also developing towards compact designs. Multiple circuit boards are crammed into a small space, and each circuit board integrates multiple electronic components. These components accumulate a large amount of heat in a short period during operation. If this heat cannot be dissipated in time, the component temperature will exceed Class I derating. Components typically operate intermittently; the non-operating time within a single orbital cycle is much longer than the operating time. When the components are not operating, heat dissipation is close to zero. Without effective insulation measures, the component temperature will fall below storage requirements. Both excessively high and low temperatures affect the performance and lifespan of the components. Traditionally, the heat dissipation and insulation of the focal plane electrical box are addressed separately. Heat dissipation is generally achieved by individually installing heat-conducting strips on the high-power electronic components of each circuit board to conduct heat to the heat dissipation surface. Before the heat reaches the heat dissipation surface, the heat conduction paths of each circuit board do not interfere with each other. Insulation is generally achieved by directly attaching polyimide film-type electric heaters to the focal plane electrical box body for heating.

[0003] Generally speaking, compact focal plane electrical boxes have relatively small dimensions, but they contain more than three circuit boards. Each circuit board is filled with electronic components of different sizes, and the distance between the components on different circuit boards is less than 1mm. Therefore, if the heat dissipation and heat preservation of the focal plane electrical box are solved separately, it will inevitably occupy a large amount of space and power resources, which is difficult for a compact focal plane electrical box to bear. Summary of the Invention

[0004] The purpose of this invention is to provide a heat dissipation and insulation system for multi-circuit board devices in a compact focal plane electrical box. This system comprehensively considers the heat dissipation and insulation of the devices, and for compact focal plane electrical boxes, it utilizes limited space and power consumption resources to control the device temperature within a reasonable range.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A compact heat dissipation and insulation system for multi-circuit board devices in a focal plane electrical box includes a heat-conducting plate, an L-shaped heat-conducting strip, a -Y-side heat-conducting bridge, a +Y-side heat-conducting bridge, a polyimide film electric heater, a main thermistor, a backup thermistor, a shielding sheet, and a semi-enclosed frame.

[0007] After the heat-conducting plate passes through the gap between the PCB boards facing each other inside the coke oven, it is installed on the frame inside the coke oven with screws on all sides, and the thickness of the heat-conducting plate is uneven.

[0008] One end of the L-shaped heat-conducting strip is thermally connected to the heat-conducting plate, with thermally conductive filler applied to the mounting interface. The other end is thermally connected to the high-power electronic components mounted on the back of the PCB board via an insulating thermally conductive pad.

[0009] One end of the -Y side thermal bridge is thermally connected to the heat dissipation surface of the -Y side coking surface electrical box, and the other end is thermally connected to the thermal plate, with thermally conductive filler applied to each installation interface;

[0010] One end of the +Y side thermal bridge is thermally connected to the heat dissipation surface of the +Y side coke box, and the other end is thermally connected to the heat-conducting plate. Thermal filler is applied to each installation interface.

[0011] The focal plane electrical box is placed inside a semi-enclosed frame, and the heat dissipation surfaces of the -Y side focal plane electrical box and the +Y side focal plane electrical box are respectively opposite to the two openings of the semi-enclosed frame. Each opening is fitted with a shielding plate by screws to cover the gap between the focal plane electrical box and the semi-enclosed frame. The shielding plate and the outer surface of the semi-enclosed frame are covered with multiple layers of heat insulation components.

[0012] The polyimide film electric heater is attached to the outer surface of the semi-enclosed frame with GD414C silicone rubber and adopts a closed-loop temperature control method. The temperature measuring point is the main thermistor component. When the main thermistor component is damaged, the thermistor backup is activated.

[0013] The inner surface of the semi-enclosed frame and the outer surface of the coke box are treated with black anodizing. The heat dissipation surfaces of the +Y side and -Y side of the coke box are sprayed with inorganic white paint.

[0014] Compared with the prior art, the beneficial effects of the technical solution of the present invention are mainly reflected in the following aspects:

[0015] (1) The present invention uses an integrated heat conduction channel built by heat conduction plate, heat conduction strip and heat conduction bridge to combine high-power electronic components on multiple circuit boards for heat conduction, which greatly reduces the space occupied and solves the problem of heat conduction difficulty caused by the small and compact space of multiple circuit board components.

[0016] (2) The present invention uses a radiant heat preservation device composed of a semi-enclosed frame and shielding sheets, which mainly plays a heat preservation role under low temperature conditions. The polyimide film electric heater is pasted on the semi-enclosed frame. At this time, the frame temperature directly heated by the electric heater is higher than the temperature of the coke surface electrical box. The heat of the frame is transferred to the shell of the coke surface electrical box through radiation, and then transferred to the device through the integrated heat conduction channel, so that the device achieves the heat preservation effect. This solves the problem of heat preservation difficulty caused by the compact coke surface electrical box itself being unable to directly paste the electric heater.

[0017] (3) The radiation heat preservation device of the present invention also plays an auxiliary role in heat dissipation under high temperature conditions. At this time, the temperature of the semi-enclosed frame is lower than the temperature of the coke box. The heat of the device is transferred to the outer shell of the box through the integrated heat conduction channel. Most of the heat is dissipated to the cold black space through the heat dissipation surface, and a small part of the heat is transferred to the frame through radiation. Attached Figure Description

[0018] Figure 1 A front view of the three circuit boards and the high-power electronic components inside the focal plane electrical box;

[0019] Figure 2 A side view of the three circuit boards and the high-power electronic components inside the focal plane electrical box;

[0020] Figure 3 This is a front view of the integrated heat conduction channel in an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the back of the integrated heat conduction channel in an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of a radiation insulation device for a coke oven.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1—PCB1 board; 2—PCB3 board; 3—PCB2 board; 4—High-power electronic component A2; 5—High-power electronic component B1; 6—High-power electronic component B2; 7—High-power electronic component B3; 8—High-power electronic component A1; 9—High-power electronic component A3; 10—Heat-conducting plate; 11—+Y side focal plane electrical box heat dissipation surface; 12—-Y side focal plane electrical box heat dissipation surface; 13—L-shaped heat-conducting strip; 14—-Y side thermal bridge; 15—+Y side thermal bridge; 16—Polyimide film type electric heater; 17—Main thermistor; 18—Thermistor backup; 19—Shielding plate; 20—Semi-enclosed frame. Detailed Implementation

[0025] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings and preferred embodiments.

[0026] The distribution of the three circuit boards and the high-power electronic components on them inside the sintered box is as follows: Figures 1-2As shown, high-power electronic components A18, A24, and A39 are mounted on the front side of PCB1 board 1, PCB2 board 3, and PCB3 board 2, respectively, while high-power electronic components B15, B26, and B37 are mounted on the back side of PCB3 board 2. The front sides of PCB1 board 1 and PCB2 board 3 are opposite to the front side of PCB3 board 2, and the gap between high-power electronic components A18, A24, and A39 is only 0.8mm.

[0027] like Figure 3 As shown, this embodiment provides a compact coking box multi-circuit board device heat dissipation and insulation system. The system includes an integrated heat conduction channel and a radiant insulation device. The integrated heat conduction channel is a complete heat conduction channel built inside the coking box for all high-power electronic components on the circuit boards. It is used to conduct heat to all high-power electronic components in combination. The integrated heat conduction channel specifically includes a heat conduction plate 10, an L-shaped heat conduction strip 13, a -Y side heat conduction bridge 14, and a +Y side heat conduction bridge 15.

[0028] like Figure 3 As shown, the heat-conducting plate 10 passes through the gap between PCB1, PCB2, and PCB3 and is installed on the internal frame of the coking panel electrical box by screws. The heat-conducting plate 10 is made of aluminum alloy and is set between the three circuit boards PCB1, PCB2, and PCB3 with a gap of 7mm. However, the gap between the high-power electronic components A18 and A24 on PCB1 and PCB2 and the high-power electronic component A39 on PCB3 is only 0.8mm. The local thickness of the heat-conducting plate 10 near the high-power electronic components A18, A24, and A39 is only 0.6mm. The high-power electronic components A18, A24, and A39 are thermally connected to the heat-conducting plate 10 through insulating thermal pads. The thickness of other parts of the heat-conducting plate 10 increases as the size and number of components decrease, reaching a maximum thickness of 5mm. Therefore, the thickness of the entire heat-conducting plate 10 is uneven and is set according to the space of the coking panel electrical box and the position of the components. The design of the entire heat-conducting plate 10 not only meets the heat conduction requirements but also conforms to the structural support requirements. One end of the L-shaped heat-conducting strip 13 is thermally connected to the heat-conducting plate 10, and the mounting interface is coated with thermally conductive filler such as GD414C silicone rubber. The other end of the L-shaped heat-conducting strip 13 is thermally connected to the high-power electronic components B15, B26, and B37 on the PCB3 board 2 via an insulating thermally conductive pad. Optionally, the L-shaped heat-conducting strip is made of aluminum alloy with a thickness of 1mm.

[0029] like Figure 4As shown, one end of the -Y side thermal bridge 14 is thermally connected to the heat dissipation surface 12 of the -Y side focal plane electrical box, and the other end of the -Y side thermal bridge 14 is thermally connected to the heat conduction plate 10; one end of the +Y side thermal bridge 15 is thermally connected to the heat dissipation surface 11 of the +Y side focal plane electrical box, and the other end of the +Y side thermal bridge 15 is thermally connected to the heat conduction plate 10; the mounting interfaces of the -Y side thermal bridge 14 and the +Y side thermal bridge 15 are coated with thermally conductive filler such as GD414C silicone rubber, and the heat dissipation surface 11 of the +Y side focal plane electrical box and the heat dissipation surface 12 of the -Y side focal plane electrical box body are sprayed with inorganic white paint. The heat-conducting plate 10, the L-shaped heat-conducting strip 13, the +Y side heat-conducting bridge 15, and the -Y side heat-conducting bridge 14 together form an integrated heat-conducting channel. The heat from the high-power electronic components A18, A24, A39, B15, B26, and B37 on PCB1 board 1, PCB2 board 3, and PCB3 board 2 is conducted through this heat-conducting channel to the +Y side focal plane electrical box heat dissipation surface 11 and the -Y side focal plane electrical box heat dissipation surface 12, and finally dissipated into the cold black space by the heat dissipation surface.

[0030] like Figure 5 As shown, the radiant heat insulation device for the focal surface electrical box includes a semi-enclosed frame 20, a shielding plate 19, a polyimide film electric heater 16, a temperature sensor (main thermistor 17 and backup thermistor 18), and a multi-layer heat insulation assembly. The focal surface electrical box is placed inside the semi-enclosed frame 20, which has two openings on the ±Y sides. The -Y side of the focal surface electrical box heat dissipation surface 12 and the +Y side of the focal surface electrical box heat dissipation surface 11 are respectively opposite to the two openings of the semi-enclosed frame 20, and each opening is fitted with a shielding plate 19 by screws. The shielding plate 19 is used to cover the gap between the focal surface electrical box and the frame 20. The outer surfaces of the semi-enclosed frame 20 and the shielding plate 19 are covered with 20 units of multi-layer heat insulation assembly. Each unit consists of a layer of polyester mesh and a layer of double-sided aluminized polyester film. The outermost layer facing the cold black space is a single-sided aluminized polyimide film. The multi-layer heat insulation assembly effectively reduces heat leakage from other components, except for the heat dissipation surface, to the cold black space environment.

[0031] The polyimide film electric heater 16 is attached to the outer surface of the semi-enclosed frame 20 using GD414C silicone rubber. Three heating zones are set on the top and sides of the semi-enclosed frame 20. At least one polyimide film electric heater 16 is attached to each heating zone using GD414C silicone rubber. Each heating circuit uses closed-loop temperature control. When selecting the target temperature, both heat dissipation and heat preservation of the device must be comprehensively considered. It is necessary not only to ensure that the device temperature meets the low-temperature storage requirements, but also to ensure that the semi-enclosed frame provides auxiliary heat dissipation for the high-temperature operating device. The polyimide film electric heater 16 uses closed-loop temperature control, with the main thermistor 17 as the temperature measuring point. When the main thermistor 17 fails, the backup thermistor 18 is activated. The main and backup thermistors cannot be used simultaneously. The inner surface of the semi-enclosed frame 20 and the outer surface of the coke box (excluding the heat dissipation surface) are treated with black anodizing. Under low-temperature conditions, the semi-enclosed frame 20, heated by an electric heater, transfers heat to the coke box outer shell via radiation, and then to the device through an integrated heat conduction channel, ultimately achieving a heat preservation effect for the device. Under high-temperature conditions, the temperature of the semi-enclosed frame 20 is lower than that of the coke box. The heat from the device is transferred to the outer shell of the box through the integrated heat conduction channel. Although most of the heat is dissipated into the cold black space through the heat dissipation surface, a small portion of the heat is transferred to the semi-enclosed frame 20 through radiation. In this case, the radiant heat preservation device also plays an auxiliary role in heat dissipation.

[0032] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0033] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A compact heat dissipation and insulation system for multi-circuit board devices in a coaxial electrical box, characterized in that, It includes a heat-conducting plate (10), an L-shaped heat-conducting strip (13), a -Y side heat-conducting bridge (14), a +Y side heat-conducting bridge (15), a polyimide film electric heater (16), a thermistor main component (17), a thermistor backup component (18), a shielding plate (19), and a semi-enclosed frame (20). After the heat-conducting plate (10) passes through the gap between the PCB boards facing each other inside the coking surface electrical box, it is installed on the frame inside the coking surface electrical box by screws around its perimeter. The thickness of the heat-conducting plate (10) is uneven. One end of the L-shaped heat-conducting strip (13) is heat-conductingly installed with the heat-conducting plate (10), and the installation interface is coated with heat-conducting filler. The other end is heat-conductingly installed with the high-power electronic components installed on the back of the PCB board through an insulating heat-conducting pad. One end of the -Y side thermal bridge (14) is thermally connected to the heat dissipation surface (12) of the -Y side focal surface electrical box, and the other end is thermally connected to the heat-conducting plate (10), and each installation interface is coated with thermally conductive filler. One end of the +Y side thermal bridge (15) is thermally connected to the heat dissipation surface (11) of the +Y side focal surface electrical box, and the other end is thermally connected to the heat-conducting plate (10). Thermal filler is applied to each installation interface. The focal surface electrical box is placed inside the semi-enclosed frame (20), and the heat dissipation surface (12) of the focal surface electrical box on the -Y side and the heat dissipation surface (11) of the focal surface electrical box on the +Y side are respectively opposite to the two openings of the semi-enclosed frame (20). Each opening is fitted with a shielding plate (19) to block the gap between the focal surface electrical box and the semi-enclosed frame (20) by screws. The shielding plate (19) and the outer surface of the semi-enclosed frame (20) are covered with multiple layers of heat insulation components. The polyimide film electric heater (16) is attached to the outer surface of the semi-enclosed frame (20) by GD414C silicone rubber and adopts a closed-loop temperature control method. The main thermistor (17) is used as the temperature measuring point. When the main thermistor (17) is damaged, the thermistor backup (18) is activated. The inner surface of the semi-enclosed frame (20) and the outer surface of the coke box are treated with black anodizing. The heat dissipation surface (11) of the +Y side of the coke box and the heat dissipation surface (12) of the -Y side of the coke box are sprayed with inorganic white paint.

2. The compact coke oven multi-circuit board device heat dissipation and insulation system according to claim 1, characterized in that, The semi-enclosed frame (20) has three heating zones on its top and sides, and each heating zone has at least one polyimide film electric heater (16) attached to it using GD414C silicone rubber.

3. The compact coke oven multi-circuit board device heat dissipation and insulation system according to claim 1, characterized in that, The multi-layer thermal insulation component consists of 20 units, each of which comprises a layer of polyester mesh and a layer of double-sided aluminized polyester film.

4. The heat dissipation and insulation system for multi-circuit board devices in a compact coaxial electrical box according to claim 1, characterized in that, The thermally conductive filler is GD414C silicone rubber.

5. The heat dissipation and insulation system for multi-circuit board devices in a compact coaxial electrical box according to claim 1, characterized in that, The L-shaped heat-conducting strip (13) is made of aluminum alloy with a thickness of 1mm.

Images