Distributed heat dissipation structure and method for PCB under high temperature working condition

Abstract

The application relates to the field of PCB heat dissipation technology, and discloses a distributed heat dissipation structure and a distributed heat dissipation method for a PCB under high-temperature working conditions, which comprises a PCB base material, electronic components are installed on the A face of the PCB base material, and active thermal control units are distributedly installed on the B face of the PCB base material and correspond to the electronic components needing to be cooled; the distributed heat dissipation structure for the PCB under the high-temperature working conditions can actively cool the electronic components (such as microprocessors, memories and the like) with large heat generation through the distributed installation of the active thermal control units on the B face of the PCB base material and corresponding to the heat generating elements, so that the highest working temperature of the system is improved, the normal operation of the system is ensured, energy waste caused by the whole-board cooling is avoided, and the heat dissipation efficiency and energy utilization rate are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of PCB heat dissipation technology, specifically to a distributed heat dissipation structure and method for PCB boards under high-temperature conditions. Background Technology

[0002] Regarding heat dissipation of circuit boards under high-temperature conditions in underground mining, there are generally two solutions in the industry: a) Place the entire circuit board inside an insulated Dewar flask. While this effectively isolates the circuit board from the high temperatures downhole, the circuit board itself also generates heat during operation. Therefore, if the circuit board operates downhole for an extended period, its temperature will still rise above the chip's maximum junction temperature.

[0003] b) Use a vapor chamber. Similar to the heat pipes widely used in the PC industry. However, while heat pipes rapidly and evenly distribute the temperature of the circuit board, they cannot truly reduce the temperature of any particular part and therefore cannot fundamentally solve the problem of localized high temperatures.

[0004] Therefore, neither of the current technical solutions can fundamentally solve the heat dissipation problem of downhole equipment.

[0005] To achieve more effective thermal management, an active cooling mechanism must be introduced, which is a "heat engine" type of heat dissipation scheme that utilizes thermodynamic principles to achieve reverse heat transfer. Active cooling is further divided into two approaches: compressor-based and semiconductor solid-state cooling. The high vibration and small size of downhole environments are clearly unsuitable for compressor-based solutions with mechanical moving parts, while traditional semiconductor cooling modules (TECs) have the following problems: Traditional TECs are typically made into rectangular structures and have a relatively large area, making them suitable for cooling larger areas but not for small-sized localized cooling. In downhole instruments that need to operate in environments above 150°C for extended periods, the allowable junction temperature for some core electronic components, especially microprocessors (MCUs) and memory chips, is generally only 125°C to 150°C. Exceeding this range will lead to a sharp increase in the risk of failure.

[0006] In contrast, other components (such as resistors, capacitors, MOSFETs, diodes, etc.) can withstand high temperatures of 175°C or even 200°C, so cooling the entire board is unnecessary and would waste energy. Therefore, the heat dissipation requirement for high-temperature downhole equipment is not overall board cooling, but rather precise and active cooling of key chip areas. This invention addresses this technical challenge by proposing a distributed heat dissipation structure for PCB boards under high-temperature conditions. It achieves localized active cooling by introducing a semiconductor thermoelectric cooling module based on the Peltier thermoelectric effect. Summary of the Invention

[0007] (a) Technical problems to be solved

[0008] To address the shortcomings of existing technologies, this invention provides a distributed heat dissipation structure and method for PCB boards under high-temperature conditions, which has the advantage of actively cooling the heat-generating areas of the PCB board under high-temperature conditions underground.

[0009] (II) Technical Solution

[0010] To achieve the aforementioned objective of actively cooling the heat-generating areas of a PCB board under high-temperature downhole conditions, this invention provides the following technical solution: a distributed heat dissipation structure for PCB boards under high-temperature conditions, comprising a PCB substrate, wherein electronic components are mounted on surface A of the PCB substrate. On the B side of the PCB substrate, active thermal control units are distributed and installed at the locations of the electronic components that require cooling. The active thermal control unit includes several pairs of P-type semiconductors and N-type semiconductors. The ends of the P-type and N-type semiconductors away from the PCB substrate establish thermal contact with the metal heat sink through a thermally conductive insulating layer, while the ends closer to the PCB substrate establish thermal contact with the PCB substrate. Thus, active cooling of electronic components is achieved through the thermoelectric effect of the active thermal control unit.

[0011] Furthermore, the electronic components establish a thermally conductive connection with the PCB substrate through thermally conductive grease or solder pads.

[0012] Furthermore, the heat between the top and bottom of the PCB substrate is transferred through copper plating vias provided inside it.

[0013] Furthermore, the P-type semiconductor and N-type semiconductor are soldered to the B-side of the PCB substrate at the ends closest to the PCB substrate, and the soldering position corresponds to the area of ​​the electronic component that needs to be cooled.

[0014] Furthermore, copper foil is provided on both the B-side and the thermally conductive insulating layer of the PCB substrate, and the active thermal control unit realizes power supply and electrical connection between P-type semiconductor and N-type semiconductor through the copper foil.

[0015] Furthermore, the P-type semiconductor and the N-type semiconductor near the PCB substrate establish thermal contact with the cold-end metal substrate through a cold-end thermally conductive insulating layer, and the cold-end metal substrate establishes thermal contact with the PCB substrate through a thermally conductive silicone pad. Both the cold-end thermally conductive insulating layer and the hot-end thermally conductive insulating layer are provided with copper foil. The active thermal control unit uses the copper foil to achieve power supply and electrical connection between the P-type semiconductor and the N-type semiconductor.

[0016] Furthermore, the thermally conductive silicone pad covers the SMD components mounted on the B side of the PCB substrate.

[0017] Furthermore, the metal substrate possesses thermal conductivity and ductility.

[0018] Furthermore, the cold-end thermally conductive insulating layer is embedded with wires for supplying power to the active thermal control unit.

[0019] Furthermore, the gap between the P-type semiconductor and the N-type semiconductor is filled with a heat-insulating buffer material.

[0020] Furthermore, the ends of the P-type semiconductor and N-type semiconductor away from the PCB substrate establish thermal contact with the hot-end metal substrate through the hot-end thermally conductive insulating layer, and the hot-end metal substrate is fixed on the metal heat sink.

[0021] Furthermore, the distributed heat dissipation structure of the present invention is not only suitable for high-temperature operating conditions of downhole instruments, but also for local active heat dissipation applications in high-heat environments such as high-power density power modules, vehicle-mounted electronic control units, and satellite electronic cabins.

[0022] (III) Beneficial Effects

[0023] Compared with the prior art, the present invention provides a distributed heat dissipation structure for PCB boards under high-temperature conditions, which has the following beneficial effects: 1. This distributed heat dissipation structure for PCB boards under high-temperature conditions replaces traditional thermal insulation or passive heat conduction methods with a thermodynamic active cooling solution. This allows the heat dissipation system to actively transfer heat under high-temperature conditions, thereby effectively reducing the operating temperature of key electronic components (such as microprocessors and memory), preventing failure or performance degradation caused by excessive junction temperature, and significantly improving the reliability and service life of electronic systems.

[0024] 2. The distributed heat dissipation structure for PCB boards under high-temperature conditions, by distributing active thermal control units in the areas corresponding to heat-generating components on the B side of the PCB substrate, can actively cool electronic components with high heat generation (such as microprocessors, memory, etc.), which not only increases the maximum operating temperature of the system and ensures the normal operation of the system, but also avoids the energy waste caused by cooling the entire board, and significantly improves heat dissipation efficiency and energy utilization.

[0025] 3. The distributed heat dissipation structure for PCB boards under high-temperature conditions establishes a stable heat conduction path between electronic components and active thermal control units by directly welding P-type and N-type semiconductors or forming a tight thermally conductive connection with the PCB substrate through a thermally conductive medium. This results in low thermal resistance and high thermal conductivity, enabling rapid heat dissipation from the working heat of the heat-generating electronic components.

[0026] 4. The distributed heat dissipation structure for PCB boards under high-temperature conditions, by filling the space between the P-type semiconductor and the N-type semiconductor with heat insulation buffer material, not only improves the shock resistance and impact resistance of the active thermal control unit and adapts to the strong vibration environment downhole, but also slows down the lateral heat diffusion in the heat conduction path, thereby further improving the focusing and guiding properties of the cooling area.

[0027] 5. The distributed heat dissipation structure for PCB boards under high-temperature conditions significantly improves the overall shock resistance and mechanical strength of the module by replacing the fragile ceramic heat dissipation plate in the traditional TEC with a metal substrate (such as a copper substrate or an aluminum substrate), making it suitable for the harsh environment of high impact and high vibration in downhole equipment. Meanwhile, the metal substrate has better thermal conductivity, which can accelerate the diffusion and release of heat at the hot end, thereby further improving the cooling efficiency.

[0028] 6. The distributed heat dissipation structure for PCB boards under high-temperature conditions features a distributed arrangement of active thermal control units, forming a multi-point collaborative active heat dissipation network. This achieves a more uniform temperature distribution while ensuring energy consumption, making it particularly suitable for scenarios with limited space and high power density in underground circuit boards. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of Embodiment 2 of the present invention; Figure 3 This is a schematic diagram of Embodiment 3 of the present invention; Figure 4 This is a flowchart of the method of the present invention; Figure 5 and Figure 6 This is a schematic diagram of Embodiment 4 of the present invention.

[0030] In the diagram: 1. PCB substrate; 2. P-type semiconductor; 3. N-type semiconductor; 4. Hot-end thermally conductive insulating layer; 5. Hot-end metal substrate; 6. Metal heat sink; 7. Thermal grease; 8. Copper via; 9. Copper foil; 10. Cold-end thermally conductive insulating layer; 11. Cold-end metal substrate; 12. Thermally conductive silicone pad; 13. Electronic components; 14. SMD components; 15. Thermal insulation buffer material; 16. Wire; 17. Reserved hole; 18. Sleeve; 19. Column; 20. Floating cylinder; 21. Positioning cap; 22. Silicone thermal pad; 23. Inner plate; 24. Spring 1; 25. Spring 2; 26. Baffle. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] Please see Figure 1 The present invention discloses a distributed heat dissipation structure for PCB boards under high temperature conditions. The heat dissipation structure is used on a PCB substrate 1 on surface A where electronic components 13 are mounted. Specifically, the heat dissipation structure is an active thermal control unit. On the B side (i.e. the opposite side of the A side) of the PCB substrate 1, active thermal control units are distributed and installed at the corresponding electronic components 13 (such as microprocessors, memory, etc.) that need to be cooled. This can actively cool the electronic components 13 that generate a lot of heat, thereby increasing the maximum operating temperature of the system and ensuring the normal operation of the system. At the same time, it avoids the energy waste caused by cooling the entire board, and significantly improves the heat dissipation efficiency and energy utilization. Moreover, the distributed arrangement of active thermal control units can form a multi-point collaborative active heat dissipation network, thereby achieving a more uniform temperature distribution while ensuring energy consumption. This is particularly suitable for scenarios with limited space and high power density, such as downhole circuit boards.

[0034] Please see Figure 1 The active thermal control unit is a semiconductor thermomechanical structure based on the thermoelectric effect. Specifically, it includes several pairs of P-type semiconductors 2 and N-type semiconductors 3, which achieve the temperature difference between the hot and cold ends through current driving. The ends of the P-type semiconductors 2 and N-type semiconductors 3 away from the PCB substrate 1 establish thermal contact with the hot-end metal substrate 5 through the hot-end thermally conductive insulating layer 4. The hot-end metal substrate 5 is fixed on the metal heat sink 6, while the ends of the P-type semiconductors 2 and N-type semiconductors 3 close to the PCB substrate 1 are soldered to the B surface of the PCB substrate 1, and the soldering position corresponds to the area of ​​the electronic component 13 that needs to be cooled, thereby achieving thermal contact with the PCB substrate 1. Furthermore, when the active thermal control unit is powered on, a thermoelectric potential difference is formed within the PN junction. Through the thermoelectric effect, the heat from the cold end can be actively transferred to the hot end and dissipated through the hot end metal substrate 5 and the metal heat sink 6, thereby achieving active cooling of the electronic component 13.

[0035] In this embodiment, the electronic component 13 establishes a thermally conductive connection with the PCB substrate 1 through the thermal grease 7 or the pad, and the heat above and below the PCB substrate 1 is transferred through the copper plating through-hole 8 provided inside it, thereby enabling the electronic component 13 to establish a stable heat conduction path with low thermal resistance and high thermal conductivity, thus enabling the rapid removal of the working heat of the heat-generating electronic component 13.

[0036] like Figure 1 As shown, copper foil 9 is provided on both the B side of the PCB substrate 1 and the thermally conductive insulating layer 4 at the hot end. The active thermal control unit is powered through the copper foil 9, which integrates the electrical connection and heat dissipation structure, eliminating the need for additional wiring. This not only reduces space occupation but also improves reliability and assembly efficiency. At the same time, the copper foil 9 is also used to realize the electrical connection between the P-type semiconductor 2 and the N-type semiconductor 3.

[0037] In this invention, the fragile ceramic heat spreader in the traditional TEC is replaced with a metal substrate (such as a copper substrate, aluminum substrate, gold substrate, or silver substrate). The metal substrate has high thermal conductivity and good toughness and ductility, which can maintain structural integrity in high vibration environments. This significantly improves the overall shock resistance and mechanical strength of the module, effectively making it suitable for the harsh environment of high impact and high vibration in downhole equipment. It avoids the risk of breakage of traditional ceramic materials, and the shock resistance performance is improved by about 3.5 times in actual tests. Meanwhile, the metal substrate has better thermal conductivity, which can accelerate the diffusion and release of heat at the hot end, reduce local hot spots, and improve cooling efficiency by about 20%.

[0038] In addition to the metal heat sink 6, heat dissipation fins can be further arranged to further improve the heat dissipation effect and ensure the long-term stable operation of the electronic system in an environment above 150℃. The hot-end metal substrate 5 and the metal heat sink 6 can be fixed together by screws or thermally conductive adhesive to ensure the stability of thermal contact and adapt to downhole vibration conditions.

[0039] Example 2

[0040] Many MCU and other chip designs require SMD components 14 to be placed on the back of the PCB substrate 1. In this case, the solution of directly soldering the P-type semiconductor 2 and N-type semiconductor 3 to the back of the PCB substrate 1 in Embodiment 1 can no longer be used. Therefore, the present invention also proposes Embodiment 2: Please see Figure 2In this embodiment, the ends of the P-type semiconductor 2 and N-type semiconductor 3 closest to the PCB substrate 1 establish thermal contact with the cold-end metal substrate 11 through the cold-end thermally conductive insulating layer 10. The cold-end metal substrate 11 then establishes thermal contact with the PCB substrate 1 through the thermally conductive silicone pad 12. Furthermore, copper foil 9 is provided on both the cold-end thermally conductive insulating layer 10 and the hot-end thermally conductive insulating layer 4. The active thermal control unit achieves power supply and electrical connection between the P-type semiconductor 2 and the N-type semiconductor 3 through the copper foil 9. Thus, the thermally conductive silicone pad 12 directly covers the SMD components 14 mounted on the B side of the PCB substrate 1, thereby reducing the temperature of the key chips on the front side of the PCB substrate 1, while also providing a certain buffering and protection effect.

[0041] In this embodiment, the thermally conductive silicone pad 12 has pre-drilled slots corresponding to the SMD components 14.

[0042] In this embodiment, a wire 16 is embedded inside the cold end thermally conductive insulating layer 10 for supplying power to the active thermal control unit.

[0043] In this embodiment, a temperature detection element (such as a thermocouple or an NTC thermistor) can also be set between the active thermal control unit and the PCB substrate 1 to monitor the temperature of the PCB substrate 1, and then automatically adjust the cooling power according to the temperature signal of the PCB substrate 1 to realize closed-loop control of temperature control. When the temperature of the PCB substrate 1 exceeds the set threshold, the control circuit automatically increases the operating current of the active thermal control unit; when the temperature is below the lower limit of the threshold, it automatically reduces or shuts off the current of the active thermal control unit, thereby achieving dynamic temperature control.

[0044] Alternatively, the entire active thermal control unit can be directly covered and installed on the surface of the electronic component 13 via a thermally conductive silicone pad 12, that is, the electronic component 13 can be directly cooled on the front side (A side) of the PCB substrate 1.

[0045] Example 3

[0046] Please see Figure 3 Based on Embodiment 1 or Embodiment 2, in this embodiment, a heat-insulating buffer material 15, such as silica aerogel, microporous ceramic fiber, or organosilicon foam, can be filled in the gap between the P-type semiconductor 2 and the N-type semiconductor 3. This can not only improve the shock resistance and impact resistance of the active thermal control unit and adapt to the strong vibration environment downhole, but also slow down the lateral heat diffusion in the heat conduction path, thereby further improving the focusing and guiding properties of the cooling area.

[0047] Example 4

[0048] Please see Figure 5 and Figure 6Based on Embodiment 2 or Embodiment 3, this embodiment further improves the connection structure between the PCB substrate 1 and the metal heat sink 6; In this embodiment, the hot-end metal substrate 5 is fixed to the metal heat sink 6 by a silicone thermal pad 22. The preferred fixing method is adhesive bonding, so that the silicone thermal pad 22 can play a flexible buffer role while conducting heat, and the thermal interface between it and the metal heat sink 6 is flat and fits together, ensuring stable heat flow conduction and avoiding the decay of thermal conductivity due to uneven thermal stress. In addition, such as Figure 5 As shown, a reserved hole 17 is pre-drilled on the PCB substrate 1, and a layer of rubber sleeve 18 is fixed on the inner wall of the reserved hole 17. The rubber sleeve 18 is made of flexible insulating material. A floating cylinder 20 is movably inserted inside the rubber sleeve 18. A positioning cap 21 is screwed to the top of the floating cylinder 20, and a baffle 26 is fixedly installed on the outer wall of the floating cylinder 20. After the floating cylinder 20 passes through the rubber sleeve 18 and the positioning cap 21 is screwed on, the floating cylinder 20 can be fixed on the PCB substrate 1. like Figure 5 The distance between the positioning cap 21 (after installation) and the baffle 26 corresponds exactly to the thickness of the PCB substrate 1, so that the floating cylinder 20 can be stably loaded on the PCB substrate 1. In this embodiment, as Figure 6 As shown, an inner plate 23 is movably disposed inside the cavity of the floating cylinder 20. A spring 24 is fixedly disposed between the top of the inner plate 23 and the inner top wall of the cavity. A column 19 is fixedly installed at the bottom of the inner plate 23, and the bottom end of the column 19 extends to the outside of the floating cylinder 20 and is welded to the metal heat sink 6 (or can be connected by screws or adhesive). In addition, a spring 25 is also sleeved on the column 19. The spring 25 is fixedly disposed between the inner bottom wall of the cavity and the inner plate 23. Thus, the spring 24 and the spring 25 form a symmetrical double spring support structure. During installation, simply pass the floating cylinder 20 through the rubber sleeve 18 and then screw on the positioning cap 21. This allows for quick assembly and disassembly. In this embodiment, spring 24 is disposed at the top of inner plate 23 and spring 25 is disposed at the bottom of inner plate 23, so that inner plate 23 can be in a suspended state that can float freely up and down. The two springs are in equilibrium during normal operation. When the metal heat sink 6 or PCB substrate 1 is subjected to external vibration or impact, the inner plate 23 can float up and down under the elastic force of the spring, thereby achieving mechanical buffering and stress absorption, effectively dispersing instantaneous impact force, reducing local stress concentration, significantly reducing the risk of solder joint fatigue and metal substrate warping, thereby improving the safety and reliability of the heat dissipation structure in the high vibration and high impact environment underground.

[0049] In the hot working state, due to the large thermal expansion coefficient of the metal material, the distance between the hot end metal substrate 5 and the metal heat sink 6 will also change slightly with the increase of temperature. In this embodiment, through the double spring system in the floating cylinder 20, the inner plate 23 can also automatically extend and retract according to the temperature change, thereby flexibly compensating for the displacement of the metal heat sink 6, preventing the decrease of the heat conduction interface clamping force due to thermal expansion and contraction, and thus ensuring the stability of thermal resistance. Even under repeated temperature cycles, the dual-spring system can maintain a tight fit between the hot-end metal substrate 5 and the metal heat sink 6.

[0050] In addition, the floating cylinder 20 is inserted into the rubber sleeve 18, so that the floating cylinder 20 can maintain a stable position in the reserved hole 17, while also having a certain radial buffering capacity. Combined with the flexible deformable silicone thermal pad 22 and thermally conductive silicone pad 12, a slight "misalignment floating" can be generated between the PCB substrate 1 and the metal heat sink 6, further improving the shock absorption effect and forming a multi-directional constraint system. In this embodiment, the floating double-spring structure can effectively cope with thermal stress, mechanical impact and structural deformation without affecting the thermal conductivity, thereby making the system more stable and reliable as a whole.

[0051] To improve vibration resistance and suppress rebound, a high-temperature resistant damping pad (such as a silicone rubber ring or a fluororubber ring) can be placed between the inner bottom wall of the cylinder cavity and the second spring 25, and / or between the inner top wall of the cylinder cavity and the first spring 24. Thus, when the inner plate 23 moves up and down, the damping pad generates frictional internal loss and viscoelastic energy dissipation between the spring end and the cylinder wall, thereby suppressing high-frequency rebound and resonance.

[0052] To prevent the inner plate 23 from "returning too quickly" under the same tension and compression of the two springs, in this embodiment, it is preferable to set the elastic coefficients of the two springs to be different (e.g., spring 1 24 has a larger stiffness, and spring 2 25 has a smaller stiffness; in the assembled state, spring 1 24 and spring 2 25 are both in a slightly compressed state, with the preload of spring 1 24 being slightly greater than that of spring 2 25, so that the system is dominated by the low-stiffness spring under small disturbances, and the two springs work together to form a high-stiffness response under large disturbances); thus, under small disturbances, the system will exhibit a more compliant response because the low-stiffness spring dominates the deformation; as the disturbance increases, the high-stiffness spring gradually contributes a larger return force, the equivalent stiffness of the system increases, thereby limiting the maximum displacement of the inner plate 23 and protecting the silicone thermal pad 22 and the thermally conductive silicone pad 12 from being damaged by excessive compression.

[0053] Example 5

[0054] Please see Figure 4This embodiment also proposes a distributed heat dissipation method for PCB boards under high-temperature conditions, which specifically includes the following steps: Step 1, Layout: Install electronic components 13 on side A of PCB substrate 1, and arrange several active thermal control units in a distributed manner on the corresponding side B, so that each active thermal control unit corresponds to one or more electronic components 13 that need to be cooled, so as to achieve targeted cooling. Step 2, Installation: Establish thermal contact between one end of the P-type semiconductor 2 and the N-type semiconductor 3 in the active thermal control unit and the PCB substrate 1, and make contact between the other end and the hot end metal substrate 5 through the hot end thermally conductive insulating layer 4, and fix the hot end metal substrate 5 on the metal heat sink 6. Step 3, Operation: The heat generated by the electronic component 13 during operation is transferred to the PCB substrate 1 via the thermal grease 7 or the pads, and then conducted to the cold end of the active thermal control unit through the copper via 8. After being powered on, the active thermal control unit actively transfers heat from the cold end to the hot end through the thermoelectric effect, and dissipates it through the hot end metal substrate 5 and the metal heat sink 6, thereby achieving active cooling.

[0055] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A distributed heat dissipation structure for PCB boards under high-temperature conditions, comprising a PCB substrate (1), wherein electronic components (13) are mounted on surface A of the PCB substrate (1), characterized in that: On the B side of the PCB substrate (1), active thermal control units are distributed and installed at the locations of the electronic components (13) that require cooling. The active thermal control unit includes several pairs of P-type semiconductors (2) and N-type semiconductors (3), wherein the P-type semiconductors (2) and N-type semiconductors (3) are in thermal contact with the metal heat sink (6) through the thermally conductive insulating layer (4) at the end away from the PCB substrate (1), and in thermal contact with the PCB substrate (1) at the end close to the PCB substrate (1), thereby achieving active cooling of electronic components (13) through the thermoelectric effect of the active thermal control unit; The P-type semiconductor (2) and N-type semiconductor (3) are in thermal contact with the hot-end metal substrate (5) through the hot-end thermally conductive insulating layer (4), and the hot-end metal substrate (5) is fixed on the metal heat sink (6). The way in which the P-type semiconductor (2) and the N-type semiconductor (3) establish thermal contact with the PCB substrate (1) at the ends closest to the PCB substrate (1) is as follows: The P-type semiconductor (2) and N-type semiconductor (3) are soldered to the B-side of the PCB substrate (1) at one end close to the PCB substrate (1), and the soldering position corresponds to the area of ​​the electronic component (13) that needs to be cooled; copper foil (9) is provided on the B-side of the PCB substrate (1) and the thermally conductive insulating layer (4) at the hot end, and the active thermal control unit realizes power supply and electrical connection between the P-type semiconductor (2) and the N-type semiconductor (3) through the copper foil (9); or The P-type semiconductor (2) and N-type semiconductor (3) near the PCB substrate (1) establish thermal contact with the cold-end metal substrate (11) through the cold-end thermally conductive insulating layer (10). The cold-end metal substrate (11) establishes thermal contact with the PCB substrate (1) through the thermally conductive silicone pad (12). Copper foil (9) is provided on both the cold-end thermally conductive insulating layer (10) and the hot-end thermally conductive insulating layer (4). The active thermal control unit realizes power supply and electrical connection between the P-type semiconductor (2) and the N-type semiconductor (3) through the copper foil (9). The thermally conductive silicone pad (12) covers the SMD components (14) mounted on the B side of the PCB substrate (1). Metal substrates have thermal conductivity and ductility, enabling them to maintain structural integrity under high vibration environments and improve shock resistance and mechanical strength.

2. The distributed heat dissipation structure for PCB boards under high-temperature conditions according to claim 1, characterized in that: The electronic components (13) establish a thermally conductive connection with the PCB substrate (1) through thermally conductive grease (7) or pads.

3. The distributed heat dissipation structure for PCB boards under high-temperature conditions according to claim 1, characterized in that: The heat on the PCB substrate (1) is transferred through the copper plating through-holes (8) inside it.

4. The distributed heat dissipation structure for PCB boards under high-temperature conditions according to claim 1, characterized in that: The cold end thermally conductive insulation layer (10) is embedded with a wire (16) for supplying power to the active thermal control unit.

5. The distributed heat dissipation structure for PCB boards under high-temperature conditions according to claim 1, characterized in that: The gap between the P-type semiconductor (2) and the N-type semiconductor (3) is filled with a heat-insulating buffer material (15).

6. A distributed heat dissipation method for PCB boards under high-temperature conditions, used in the distributed heat dissipation structure for PCB boards under high-temperature conditions as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Layout: Electronic components (13) are installed on the A side of the PCB substrate (1), and several active thermal control units are distributed on the corresponding B side, so that each active thermal control unit corresponds to one or more electronic components (13) that need to be cooled. S2, Installation: Establish thermal contact between one end of the P-type semiconductor (2) and N-type semiconductor (3) in the active thermal control unit and the PCB substrate (1), and make contact between the other end and the hot end metal substrate (5) through the hot end thermally conductive insulating layer (4), and fix the hot end metal substrate (5) on the metal heat sink (6); S3, Operation: The heat generated by the electronic components (13) during operation is transferred to the PCB substrate (1) through the thermal grease (7) or the pads, and then conducted to the cold end of the active thermal control unit through the copper via (8); After being powered on, the active thermal control unit actively transfers heat from the cold end to the hot end through the thermoelectric effect, and dissipates it through the hot end metal substrate (5) and metal heat sink (6), thereby achieving active cooling.

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