High-efficiency heat dissipation resistor

Abstract

The invention discloses a high-efficiency heat dissipation resistor, and relates to the technical field of electronic devices, and the high-efficiency heat dissipation resistor comprises a resistor disc, a dynamic heat conduction module, a heat flow regulation and control module, a heat dissipation module and two symmetrically arranged pin wires which are sequentially arranged in an attached manner; the two pin wires are electrically connected with the two sides of the resistor disc respectively; the dynamic heat conduction module is used for absorbing heat of the resistor disc and buffering temperature fluctuation; the heat flow regulation and control module is used for uniformizing heat flow distribution and preventing heat concentration; the heat dissipation module is used for dissipating heat, and rapid heat dissipation is achieved. The dynamic heat conduction module can achieve graded temperature buffering, when the resistor disc operates, the inner layer rapidly absorbs initial heat, the outer layer buffers higher temperature in a relay mode, the temperature peak value is effectively reduced, temperature fluctuation is slowed down, the resistance consistency is improved, the service life of the resistor is prolonged, and the dynamic heat conduction module is particularly suitable for high-power application scenes.

Description

Technical Field

[0001] The invention relates to the technical field of electronic devices, and in particular to a resistor with high-efficiency heat dissipation. Background Art

[0002] As a key component in modern electronic devices, chip resistors are widely used in precision circuits, high-power modules and harsh environments (such as automotive electronics and aerospace). As the power density of electronic devices continues to increase, the heat generated by chip resistors during high-power operation increases significantly, which places higher requirements on heat dissipation performance and resistance stability.

[0003] In the prior art, the heat dissipation of chip resistors mainly relies on a single metal heat sink, circuit board heat conduction, and can also be achieved by increasing the heat sink area or using a high thermal conductivity substrate (such as alumina ceramic). However, when the power is increased to above 7W, the surface temperature of the resistor often exceeds 120°C-140°C, resulting in thermal stress accumulation, resistance drift and even material aging; this static heat dissipation method in the prior art has obvious limitations under high heat load or complex working conditions, and the heat dissipation efficiency is poor. Summary of the invention

[0004] The purpose of the present invention is to provide a resistor with high heat dissipation efficiency, which solves the problem that the static heat dissipation method in the prior art has obvious limitations under high heat load or complex working conditions and has poor heat dissipation efficiency.

[0005] The present invention solves the above technical problems through the following technical solutions, which include: A resistor sheet, a dynamic heat conduction module, a heat flow control module, a heat dissipation module and two symmetrically arranged pin lines are sequentially bonded; The two pin lines are electrically connected to two sides of the resistor respectively; The dynamic heat conduction module is used to absorb the heat of the resistor and buffer the temperature fluctuation. The dynamic heat conduction module includes a polyurea isolation shell and a phase change filler filled in the inner cavity of the polyurea isolation shell; The heat flow control module is used to even out the heat flow distribution and prevent heat concentration. The heat flow control module includes a foil shell and a capillary wick arranged in the inner cavity of the foil shell. The gap inside the capillary wick forms a micro channel, and the micro channel is filled with a working fluid. The center of the heat flow control module is a high temperature zone, and the surrounding area is a condensation zone. The heat dissipation module is used to dissipate heat to achieve rapid heat dissipation.

[0006] Preferably, the polyurea isolation shell has two overlapping inner cavities, both of which are filled with phase-change fillers, and the melting point of the phase-change filler close to the resistor is lower than the melting point of the phase-change filler far from the resistor.

[0007] Preferably, the phase change filler is a mixture of 85% paraffin wax, 10% graphene nanosheets and 5% chopped carbon fibers; The melting point of the phase change filling close to the resistor is 90°-95°, and the melting point of the other phase change filling is 110°-115°.

[0008] Preferably, the capillary core comprises microgrooves opened on the inner wall of the foil shell and a porous material filled in the inner cavity of the foil shell.

[0009] Preferably, the outer side of the heat flow regulating module extends out of the outer side of the dynamic heat conduction module, so that the outer edge of the condensation zone is located outside the dynamic heat conduction module.

[0010] Preferably, the heat dissipation module includes an inner heat conductive sheet bonded to the heat flow regulation module, an outer heat dissipation sheet is bonded to a side of the inner heat conductive sheet away from the heat flow regulation module, a plurality of evenly distributed heat dissipation holes are provided on the outer side of the heat dissipation hole, a micro bimetallic sheet fixed to the outer heat dissipation sheet is provided, an opening is formed between the micro bimetallic sheet and the heat dissipation hole, and the micro bimetallic sheet deforms with temperature to achieve adaptive adjustment of the size of the opening.

[0011] Preferably, the micro bimetallic sheet includes a first heat sink fin fixed to an external heat sink and a second heat sink fin fitted to the first heat sink fin, the second heat sink fin is located on a side close to the heat dissipation hole, and the thermal expansion coefficient of the first heat sink fin is smaller than that of the second heat sink fin.

[0012] Preferably, the first heat sink fins are made of nickel material, and the second heat sink fins are made of copper material.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. The dynamic heat conduction module can achieve graded temperature buffering. When the resistor is running, the inner layer quickly absorbs the initial heat, and the outer layer relays to buffer higher temperatures, effectively reducing the temperature peak, smoothing temperature fluctuations, improving resistance consistency, and extending the service life of the resistor, which is particularly suitable for high-power application scenarios; 2. The heat flow control module adopts a copper foil shell and a capillary core, which is filled with working fluid. The heat flow is uniformed through the vaporization-condensation cycle. The heat in the central high-temperature area quickly diffuses to the surrounding condensation area. The condensation area extends beyond the dynamic heat conduction module to enhance the heat dissipation capacity. The micro-grooves and porous materials of the capillary core support the rapid reflux of the working fluid to form an efficient cycle to prevent heat concentration. The high thermal conductivity of the copper foil accelerates heat transfer, making the temperature distribution more uniform, reducing local hot spots, improving system stability, and ensuring that heat is effectively transferred to the heat dissipation module. It is suitable for continuous operation under complex working conditions; 3. The internal heat conducting sheet of the heat dissipation module efficiently conducts the heat of the heat flow control module, and the heat dissipation holes of the external heat dissipation sheet cooperate with the bimetallic sheet to dynamically adjust the air circulation. At high temperatures, the bimetallic sheet bends to increase the opening and enhance convection heat dissipation; at low temperatures, the opening is reduced to reduce heat loss. This design flexibly adjusts the heat dissipation according to power changes, maintains temperature stability, and avoids overcooling or overheating; the structure is durable and compact, which improves heat dissipation efficiency while extending life, and is suitable for a variety of operating environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a schematic diagram of a partial cross-sectional structure of the present invention; Figure 3 for Figure 2 A is an enlarged structural diagram; Figure 4 It is a schematic diagram of the main structure of the present invention.

[0015] The numbers in the figure represent: 1-resistor; 21-phase change filling; 22-polyurea isolation shell; 3-heat flow control module; 31-foil shell; 32-capillary wick; 4-heat dissipation module; 41-internal heat conductive sheet; 42-external heat sink; 43-heat dissipation hole; 44-micro bimetallic sheet; 441-first heat dissipation fin; 442-second heat dissipation fin; 5-epoxy resin shell; 6-pin wire. DETAILED DESCRIPTION

[0016] The above and other technical features and advantages of the present invention are described in more detail below in conjunction with the accompanying drawings.

[0017] This embodiment provides a technical solution: a resistor with high efficiency heat dissipation, such as Figures 1 to 4 As shown, it includes a resistor sheet 1, a dynamic heat conduction module, a heat flow control module 3, a heat dissipation module 4 and two symmetrically arranged pin lines 6, which are sequentially bonded, and an epoxy resin shell 5 is arranged outside the resistor sheet 1 and the dynamic heat conduction module. Through multi-level thermal management design, efficient heat dissipation, heat flow uniformity and resistance stability are achieved, which is particularly suitable for high-power operation (such as 7W-10W) and precision electronic applications under complex working conditions.

[0018] The resistor 1 is a heating core and is usually made of a high thermal conductivity alloy (such as a copper-based material). It is responsible for converting electrical energy into thermal energy and realizing circuit functions through resistance characteristics.

[0019] The two pins 6 are electrically connected to the two sides of the resistor 1, and both pins 6 are Z-shaped structures with large angles (i.e., the corners are close to 90°), which leaves enough space for the heat flow control module 3 and the heat dissipation module 4 to ensure the heat dissipation effect. The pins 6 are electrically connected to the resistor 1 to provide a current input and output channel. The pins 6 are made of highly conductive materials (such as copper or nickel-plated copper) to ensure a reliable connection between the resistor 1 and the external circuit, and at the same time, part of the heat is initially discharged through the fitting design with the external circuit.

[0020] The dynamic heat conduction module is used to absorb the heat of the resistor 1 and buffer the temperature fluctuation. The dynamic heat conduction module includes a polyurea isolation shell 22 and a phase change filler 21 filled in the inner cavity of the polyurea isolation shell 22 .

[0021] Polyurea has excellent high temperature resistance and chemical stability, and can maintain integrity at the resistor operating temperature (up to 150°C). The polyurea isolation shell 22 firmly wraps the phase change filler 21 to prevent it from leaking when it is in liquid state.

[0022] The resistor 1 generates heat when operating at high power (such as 7W-10W), and the surface temperature quickly rises to above 90°C. The heat is transferred to the dynamic heat conduction module through direct contact, and the phase change filler 21 in the polyurea isolation shell 22 senses the temperature increase. When the temperature reaches 90°C-95°C, the phase change filler 21 melts from solid to liquid, absorbing a large amount of latent heat, effectively slowing down the rate of temperature rise.

[0023] In an optional embodiment, the polyurea isolation shell 22 has two overlapping inner cavities, both of which are filled with phase change fillers 21 to form a graded heat absorption mechanism. Its function is still to absorb the heat of the resistor 1 and buffer temperature fluctuations, but the double-layer design significantly enhances the thermal management capability through graded phase change. The phase change filler 21 close to the resistor 1 has a lower melting point (90°C-95°C) for rapid response to initial heat loads; the phase change filler 21 far from the resistor 1 has a higher melting point (110°C-115°C) for buffering higher temperatures to ensure dynamic temperature stability under high power operation.

[0024] When the resistor 1 is in operation, heat is transferred to the phase change filling 21 of the inner layer (close to the resistor 1) through contact. When the temperature reaches 90°C-95°C, the inner phase change filling 21 melts from solid to liquid, absorbs latent heat, and quickly buffers the initial heat load, forming a first-level temperature platform, maintaining the temperature within the range of 90°C-95°C. When the power continues to increase or the heat accumulates, the temperature exceeds 95°C and approaches 110°C, the phase change filling 21 of the outer layer (far away from the resistor 1) begins to melt, absorbs additional heat, and forms a second-level temperature platform, maintaining the temperature at 110°C-115°C, prolonging the heat absorption time and preventing the temperature from quickly breaking through to above 120°C.

[0025] After absorbing heat, the inner layer quickly transfers it to the outer layer, and the outer layer then transfers it to the heat flow control module. Gradient heat transfer reduces thermal resistance and ensures efficient heat extraction. The double-layer melting point covers a wider temperature range and can better adapt to power fluctuations and complex working conditions than a single layer, thereby improving application flexibility.

[0026] Phase change filler 21 is the core material of the dynamic heat conduction module, which is used to absorb the heat of the resistor 1 and buffer temperature fluctuations. Its formula is a mixture of 85% paraffin, 10% graphene nanosheets and 5% chopped carbon fibers to form a composite phase change material. Among them, paraffin as the main phase change component provides latent heat absorption capacity, and graphene nanosheets and chopped carbon fibers are used as reinforcement materials to improve thermal conductivity and structural performance. This combination design is designed to optimize heat absorption, transfer efficiency and material stability to meet the heat dissipation needs of high-power resistors.

[0027] Paraffin wax is a base material, which is an alkane organic phase change material with an adjustable melting point (90°C-95°C or 110°C-115°C in this scheme) and a latent heat of about 200 J / g. Paraffin wax is stable in solid state and absorbs heat significantly after melting, which is the main source of heat buffering. Graphene nanosheets are two-dimensional carbon materials with a thermal conductivity of up to 3000-5000 W / m·K. Graphene is added to paraffin wax in a uniformly dispersed form to improve the thermal conductivity of the composite material and enhance the distribution efficiency of heat in the phase change filling. Chopped carbon fiber is a one-dimensional fiber material with a thermal conductivity of about 500-1000 W / m·K. Carbon fiber is distributed in a network shape, providing a heat transfer path and mechanical reinforcement, improving the brittleness and thermal stability of paraffin wax. After the paraffin wax is melted, graphene nanosheets and chopped carbon fibers are added, and they are evenly mixed by ultrasonic dispersion and mechanical stirring, and a solid composite material is formed after cooling.

[0028] The heat flow control module 3 is used to prevent the heat generated by the resistor 1 from being concentrated locally through rapid transfer and uniform distribution of heat, thereby avoiding damage to the resistance stability and component life caused by high-temperature hot spots; the heat flow control module 3 includes a foil shell 31 and a capillary core 32 arranged in the inner cavity of the foil shell 31, and the gap inside the capillary core 32 forms a microchannel, and the microchannel is filled with a working fluid; the central part of the heat flow control module 3 is a high-temperature zone, and the surrounding parts are condensation zones; heat flow control is achieved through the phase change cycle of the working fluid, the center is a high-temperature zone, and the surrounding parts are condensation zones, forming a clear heat flow direction.

[0029] The foil shell 31 is made of high thermal conductivity copper foil to form a flexible closed cavity. The foil shell 31 is both a heat transfer interface and a sealed container for the working fluid. It is resistant to high temperatures and flexible enough to be adapted to miniaturized design.

[0030] The capillary core 32 is arranged in the inner cavity of the foil shell, and is composed of micro grooves etched on the inner wall and porous materials (such as sintered copper fibers, pores of 10-30μm, porosity of 50%-70%). The internal gap of the capillary core forms a micro channel, which not only supports liquid reflux but also serves as a vapor diffusion path.

[0031] The working fluid is a low-boiling point liquid (such as ethanol, boiling point 78°C, latent heat 850 J / g) filled in the microchannel, accounting for 10%-20% of the cavity volume, and drives heat transfer after vaporization in the high-temperature area.

[0032] During operation, the high temperature area in the center (temperature 100°C-120°C) receives heat from the dynamic heat conduction module, which exceeds the boiling point of the working fluid. The working fluid in the capillary core absorbs heat and vaporizes, absorbing latent heat to prevent the center temperature from being too high, and generates steam. The local pressure rises, and the steam diffuses from the high temperature area to the surrounding condensation area along the microchannels inside the capillary core. The diffusion is driven by the pressure difference, and the steam cools in the condensation area and condenses into liquid, releasing latent heat, and the heat is transferred to the heat dissipation module 4. The condensed working fluid flows back to the high temperature area through the microchannels between the microgrooves of the capillary core and the porous material (the force comes from the surface tension and adhesion of the liquid, and it flows spontaneously, and the principle is similar to that of a sponge absorbing water), forming a closed loop.

[0033] The working fluid circulation in the heat flow control module 3 quickly disperses the heat from the central high-temperature area to the condensation area, reducing the temperature difference from 20°C-30°C to 3°C-5°C, effectively preventing heat concentration and reducing the risk of local overheating.

[0034] The outer side of the heat flow control module 3 extends beyond the outer side of the dynamic heat conduction module so that the outer edge of the condensation zone is located outside the dynamic heat conduction module. This design optimizes the condensation effect by expanding the size of the condensation zone and the extended part is not connected to the dynamic heat conduction module. By expanding the condensation zone and approaching the heat dissipation module 4, the working fluid circulation efficiency is improved, the heat flow distribution is further uniformed, and heat concentration is prevented.

[0035] The heat dissipation module 4 is used to dissipate heat and achieve rapid heat dissipation. The heat dissipation module 4 includes an inner heat conductive sheet 41 that is bonded to the heat flow regulation module 3. The inner heat conductive sheet 41 is made of high thermal conductivity material (such as aluminum-magnesium alloy), is tightly bonded to the heat flow regulation module 3, and is responsible for receiving and conducting heat; an outer heat sink 42 is bonded to the side of the inner heat conductive sheet 41 away from the heat flow regulation module 3. The side is made of aluminum alloy, and a plurality of heat dissipation holes 43 are evenly arranged on the surface to increase the heat dissipation area and air circulation channel; a micro bimetallic sheet 44 fixed to the outer heat sink 42 is arranged on the outer side of the heat dissipation hole 43, and an opening (angle range 5°-15°) is formed between the micro bimetallic sheet 44 and the heat dissipation hole 43. The micro bimetallic sheet 44 deforms with the temperature to achieve adaptive adjustment of the size of the opening, so as to control the air flow through the temperature deformation of the bimetallic sheet 44.

[0036] The inner heat conducting sheet 41 receives heat from the heat flow control module 3 and quickly transfers it to the outer heat sink 42 by virtue of its high thermal conductivity. The heat dissipation holes 43 of the outer heat sink 42 form microchannels, and air flows through the openings to take away the heat. The micro bimetallic sheet 44 deforms with temperature changes, with a smaller opening at low temperatures and a larger opening at high temperatures, thereby enhancing convection efficiency.

[0037] The surface of the outer heat sink 42 may be coated with a high emissivity coating (such as graphene-alumina) to dissipate part of the heat to the environment through infrared radiation, further assisting in heat dissipation.

[0038] The micro bimetal 44 is a key component in the heat dissipation module 4, fixed to the outside of the heat dissipation hole 43 of the outer heat dissipation fin 42, and is used to adjust the opening size of the heat dissipation hole through temperature deformation to achieve adaptive heat dissipation. The micro bimetal 44 includes a first heat dissipation fin 441 fixed to the outer heat dissipation fin 42 and a second heat dissipation fin 442 attached to the first heat dissipation fin 441, the second heat dissipation fin 442 is on the side close to the heat dissipation hole 43, and the thermal expansion coefficient of the first heat dissipation fin 441 is smaller than that of the second heat dissipation fin 442.

[0039] In an optional embodiment, the first heat sink fin 441 is made of nickel material, and the second heat sink fin 442 is made of copper material. The thermal expansion coefficient of copper is greater than that of nickel, and the expansion difference between the two is used to achieve deformation and dynamically control the heat dissipation efficiency.

[0040] When the temperature rises, the expansion of the first heat sink fin 441 is smaller than that of the second heat sink fin 442. Due to the difference in thermal expansion coefficients, the bimetallic strip bends to one side of the first heat sink fin 441, and the degree of the opening increases from 5° to 15°, thereby increasing the air flow through the heat dissipation hole. When the temperature drops, the micro bimetallic strip 44 rebounds, and the degree of the opening returns to 5°, thereby reducing air circulation and maintaining moderate heat dissipation.

[0041] The high thermal conductivity of copper quickly transfers the heat from the external heat sink 42 to the micro bimetallic sheet 44, and the nickel layer assists in heat dissipation and provides structural stability.

[0042] The above description is only a preferred embodiment of the present invention, which is only illustrative and not restrictive of the present invention. Those skilled in the art understand that many changes, modifications, and even equivalences may be made to the present invention within the spirit and scope defined by the claims of the present invention, but all of them will fall within the scope of protection of the present invention.

Claims

1. A resistor with high heat dissipation efficiency, characterized in that: It comprises a resistor sheet (1), a dynamic heat conduction module, a heat flow control module (3), a heat dissipation module (4), and two symmetrically arranged lead wires (6); The two pin wires (6) are electrically connected to two sides of the resistor (1) respectively; The dynamic heat conduction module is used to absorb the heat of the resistor (1) and buffer temperature fluctuations, and the dynamic heat conduction module comprises a polyurea isolation shell (22) and a phase change filler (21) filled in an inner cavity of the polyurea isolation shell (22); The heat flow control module (3) is used to even out the heat flow distribution and prevent heat concentration. The heat flow control module (3) comprises a foil shell (31) and a capillary core (32) arranged in the inner cavity of the foil shell (31). The gap inside the capillary core (32) forms a micro channel, and the micro channel is filled with a working fluid. The central part of the heat flow control module (3) is a high temperature zone, and the surrounding area is a condensation zone. The heat dissipation module (4) is used to dissipate heat to achieve rapid heat dissipation.

2. The resistor with high heat dissipation efficiency as claimed in claim 1, characterized in that: The polyurea isolation shell (22) has two overlapping inner cavities, both inner cavities are filled with phase change fillers (21), and the melting point of the phase change filler (21) close to the resistor (1) is lower than the melting point of the phase change filler (21) far from the resistor (1).

3. The resistor with high heat dissipation efficiency as claimed in claim 2, characterized in that: The phase change filler (21) is a mixture of 85% paraffin wax, 10% graphene nanosheets and 5% chopped carbon fibers; The melting point of the phase change filler (21) close to the resistor (1) is 90°-95°, and the melting point of the other phase change filler (21) is 110°-115°.

4. The resistor with high heat dissipation efficiency as claimed in claim 1, characterized in that: The capillary core (32) comprises a microgroove opened on the inner wall of the foil shell (31) and a porous material filled in the inner cavity of the foil shell (31).

5. The resistor with high heat dissipation efficiency as claimed in claim 1 or 4, characterized in that: The outer side of the heat flow regulating module (3) extends beyond the outer side of the dynamic heat conduction module, so that the outer edge of the condensation zone is located outside the dynamic heat conduction module.

6. The resistor with high heat dissipation efficiency as claimed in claim 1, characterized in that: The heat dissipation module (4) comprises an inner heat conducting sheet (41) which is arranged in close contact with the heat flow control module (3); an outer heat dissipation sheet (42) is arranged in close contact with a surface of the inner heat conducting sheet (41) which is away from the heat flow control module (3); a plurality of evenly distributed heat dissipation holes (43) are provided on the outer side of the heat dissipation hole (43); a micro bimetallic sheet (44) fixed to the outer heat dissipation sheet (42) is arranged outside the heat dissipation hole (43); an opening is formed between the micro bimetallic sheet (44) and the heat dissipation hole (43); the micro bimetallic sheet (44) deforms with temperature to achieve adaptive adjustment of the size of the opening.

7. The resistor with high heat dissipation efficiency as claimed in claim 6, characterized in that: The micro bimetallic sheet (44) comprises a first heat dissipation fin (441) fixed to an external heat dissipation fin (42) and a second heat dissipation fin (442) arranged in close contact with the first heat dissipation fin (441), the second heat dissipation fin (442) being located on a side close to the heat dissipation hole (43), and the thermal expansion coefficient of the first heat dissipation fin (441) being smaller than that of the second heat dissipation fin (442).

8. The resistor with high heat dissipation efficiency as claimed in claim 7, characterized in that: The first heat dissipation fins (441) are made of nickel material, and the second heat dissipation fins (442) are made of copper material.

Images