High power alloy resistor with matching heat sink
Patent Information
- Application Number
- CN202611368625.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-04
- Publication Date
- 2026-10-27
AI Technical Summary
[0002]高功率合金电阻广泛应用于新能源储能、变频器、电源设备等领域，常作为开尔文式分流器实现大电流采样检测功能，现有开尔文式合金分流器在高功率工况下，合金本体持续消耗电能并产生大量焦耳热，多数产品仅依靠自身金属电极与PCB焊盘进行散热，散热面积有限，热量容易在电阻本体位置聚集；电阻本体长时间处于高温状态下，会造成合金材料阻值发生漂移，直接降低电流采样测量精度，严重时会加速元件老化，缩短整体使用寿命；
[0015]本发明具有如下优点：本发明通过改进在此提供一种配套散热器的高功率合金电阻，与同类型设备相比，具有如下改进：
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Figure CN122991782A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electronic component technology, specifically a high-power alloy resistor that is matched with a heat sink. Background Technology
[0002] High-power alloy resistors are widely used in new energy storage, frequency converters, power supply equipment and other fields. They are often used as Kelvin shunts to achieve high current sampling and detection functions. Under high power conditions, the alloy body of existing Kelvin alloy shunts continuously consumes electrical energy and generates a large amount of Joule heat. Most products rely only on their own metal electrodes and PCB pads for heat dissipation, which has a limited heat dissipation area and heat tends to accumulate at the resistor body. When the resistor body is in a high-temperature state for a long time, the resistance value of the alloy material will drift, which directly reduces the accuracy of current sampling and measurement. In severe cases, it will accelerate component aging and shorten the overall service life.
[0003] Furthermore, for some alloy resistor products on the market with added heat sinks, the assembly gap between the heat sink and the resistor body is difficult to control. Air gaps increase contact thermal resistance and result in poor heat conduction efficiency. At the same time, unreasonable assembly structure design can easily lead to heat sink displacement and uneven pressure on the heat conduction medium. This not only fails to stably dissipate heat but also easily causes deformation of the four pins of the Kelvin shunt under stress, resulting in poor soldering and pin misalignment. This affects the reliability of the sampling circuit connection and makes it difficult to meet the long-term stable operation requirements of high-power equipment. Summary of the Invention
[0004] Therefore, in order to overcome the above-mentioned shortcomings, the present invention provides a high-power alloy resistor for use with a matching heat sink.
[0005] This invention is achieved by constructing a high-power alloy resistor with a matching heat sink. The device includes a heat sink, which is fixed to the upper surface of a Kelvin shunt by thermally conductive adhesive. The lower surface of the heat sink has a flat bonding plane, and the outline of the bonding plane matches the outline of the heat-generating area on the upper surface of the Kelvin shunt. The thermally conductive adhesive completely fills the space between the bonding plane of the heat sink and the upper surface of the Kelvin shunt, and the thermally conductive adhesive has no local missing adhesive or air bubbles.
[0006] Preferably, the Kelvin shunt includes an alloy resistor substrate and four sets of independent terminals, which are divided into two sets of current input / output terminals and two sets of voltage sampling terminals.
[0007] Preferably, the edge of the heat sink avoids the four independent terminals of the Kelvin shunt, and the heat sink does not make physical contact with the four independent terminals.
[0008] Preferably, the upper surface of the radiator is integrally formed with multiple parallel heat dissipation ribs, which are evenly arranged along the length of the radiator to increase the heat exchange area with air convection.
[0009] Preferably, the thermally conductive adhesive is made of a highly thermally conductive soft gel material, and the thermally conductive adhesive has a uniform thickness to buffer the mechanical stress generated during the assembly between the heat sink and the Kelvin shunt.
[0010] Preferably, the upper surface of the Kelvin shunt alloy resistor substrate is an exposed metal surface without insulation coverage, and the exposed metal surface is in direct and close contact with the thermally conductive adhesive to achieve heat conduction.
[0011] Preferably, the radiator is made of aluminum alloy and the entire radiator is anodized. Except for the lower surface that is attached to the plane, the other outer surfaces of the radiator are covered with an oxide protective layer.
[0012] Preferably, positioning holes are provided on both sides of the heat sink for fasteners to pass through. The fasteners only press the heat sink, and the pressure is evenly transmitted to the Kelvin distributor through the thermally conductive adhesive. The fasteners do not directly contact the Kelvin distributor.
[0013] Preferably, the positioning hole of the heat sink is a countersunk hole, with the countersunk part facing the upper surface of the heat sink, and the head of the fastener is completely contained inside the countersunk hole, without the head of the fastener protruding from the upper surface of the heat sink.
[0014] Preferably, the thickness of the thermally conductive adhesive layer is controlled at 0.2-0.5mm, the planar projected area of the thermally conductive adhesive is smaller than the area of the heat sink contact plane, and an overflow gap is reserved between the edge of the thermally conductive adhesive and the edge of the heat sink contact plane to prevent the thermally conductive adhesive from overflowing to the four independent terminal positions of the Kelvin shunt.
[0015] The present invention has the following advantages: By providing an improved high-power alloy resistor with a matching heat sink, the present invention has the following improvements compared with similar devices:
[0016] The high-power alloy resistor described in this invention, equipped with a matching heat sink, achieves efficient heat conduction and release through the combined structure of the heat sink, thermally conductive adhesive, and Kelvin shunt. The thermally conductive adhesive eliminates air gaps at the contact surface to reduce contact thermal resistance and buffer assembly mechanical stress. Combined with the heat sink's heat dissipation fins for convection heat dissipation, terminal avoidance, and positioning hole clamping force transmission design, it effectively suppresses the operating temperature rise of the Kelvin shunt, reduces resistance drift caused by high temperature, avoids terminal deformation under pressure, ensures the accuracy of current sampling and measurement under high current conditions, and extends the service life of the overall component. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of the present invention.
[0018] Among them: radiator-1, thermal adhesive-2, Kelvin shunt-3. Detailed Implementation
[0019] The following is in conjunction with the appendix Figure 1 The principles and features of the present invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.
[0020] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention from the specific circumstances. The embodiments of this invention will now be described based on its overall structure.
[0022] Please see Figure 1This invention discloses a high-power alloy resistor with a matching heat sink, comprising a heat sink 1, which is attached to the upper surface of a Kelvin shunt 3, with thermally conductive adhesive 2 sandwiched between them. The thermally conductive adhesive 2 firmly bonds the heat sink 1 and the Kelvin shunt 3 together. A flat bonding surface is made under the heat sink 1, the shape and size of which correspond exactly to the outline of the heat-generating area on the Kelvin shunt 3, ensuring that the two can be aligned and bonded over a large area. The thermally conductive adhesive 2 fills all the gaps between the bonding surface of the heat sink 1 and the upper surface of the Kelvin shunt 3, preventing any missing adhesive or air bubbles, ensuring smooth heat transfer. The Kelvin shunt 3 has an alloy resistor substrate and four sets of independent terminals. These four sets of terminals are divided into two sets of current input / output terminals and two sets of voltage sampling terminals, responsible for conducting large currents and acquiring voltage signals, respectively. The edges of the heat sink 1 are recessed inwards to avoid the four sets of independent terminals of the Kelvin shunt 3, preventing the heat sink 1 from touching these terminals and thus preventing interference with the electrical connection. Multiple parallel heat dissipation fins are integrally machined on the top surface of the heat sink 1, arranged neatly along its length to increase the contact area with air and improve convection heat dissipation. The thermally conductive adhesive 2 uses a highly thermally conductive soft gel material with a consistent adhesive layer thickness to counteract [heat transfer issues]. The mechanical stress generated during the assembly of radiator 1 and Kelvin shunt 3; the top surface of the alloy resistor substrate of Kelvin shunt 3 is an exposed metal surface without an insulating coating, which is directly attached to the thermally conductive adhesive 2 to reduce the obstruction of heat transfer; radiator 1 is made of aluminum alloy and the entire radiator 1 is anodized, with an oxide protective layer formed on all outer surfaces except the bottom contact surface, which serves as a rust prevention and protection; radiator 1 has positioning holes on both sides for fasteners to be inserted. The fasteners only press down on radiator 1, and the pressure is then evenly transferred to Kelvin shunt 3 through the thermally conductive adhesive 2. The fasteners themselves do not directly press down on radiator 1. When contacting the Kelvin shunt 3, avoid damaging the shunt body; the positioning holes on the heat sink 1 are countersunk, with the countersunk opening facing the upper surface of the heat sink 1, allowing the fastener head to be completely hidden inside the countersunk hole, without the fastener head protruding above the upper surface of the heat sink 1, preventing protrusions that could scratch surrounding components; the thickness of the thermally conductive adhesive 2 is controlled at 0.2-0.5mm, and the coverage area of the thermally conductive adhesive 2 is slightly smaller than the contact surface of the heat sink 1, leaving excess adhesive space at the edges of the thermally conductive adhesive 2 and the contact surface of the heat sink 1 to prevent excess thermally conductive adhesive 2 from flowing onto the four independent terminals of the Kelvin shunt 3 after pressing, causing defects.
[0023] The working principle of the high-power alloy resistor in a matching heat sink according to this embodiment is as follows:
[0024] First, when this device is working, a large current is connected to the two sets of current input and output terminals of the Kelvin shunt 3. The current flows through the internal alloy resistor matrix of the Kelvin shunt 3 and generates Joule heat. The two sets of voltage sampling terminals independently collect the voltage signal at both ends of the alloy matrix, thereby completing the current detection and sampling work.
[0025] Secondly, the heat generated by the alloy substrate of the Kelvin shunt 3 is first conducted to the upper surface, and the heat is continuously transferred to the heat sink 1 by the tightly filled thermally conductive adhesive 2. The thermally conductive adhesive 2 eliminates the air gap between the contact surface of the heat sink 1 and the Kelvin shunt 3, reducing the contact thermal resistance. At the same time, the soft material absorbs the assembly extrusion stress and avoids the direct mechanical force causing the terminal deformation damage of the Kelvin shunt 3.
[0026] Third, after heat enters the radiator 1, part of it radiates outward through the radiator 1 body, while the other part undergoes convective heat exchange with the surrounding airflow through the heat dissipation fins on the radiator 1, dissipating the heat to the external environment. The edges of the radiator 1 are designed to avoid contact with the four sets of terminals of the Kelvin shunt 3, so the radiator 1 will not touch the sampling or current terminals and will not interfere with the electrical connection. The radiator 1 is pressed by fasteners with positioning holes on both sides, and the pressure is only applied to the radiator 1. The pressure is then evenly applied to the Kelvin shunt 3 through the thermally conductive adhesive 2, preventing the fasteners from damaging the Kelvin shunt 3. The heat dissipation path effectively suppresses the operating temperature rise of the Kelvin shunt 3, reduces the resistance drift caused by high temperature, ensures the sampling and measurement accuracy under high current conditions, and extends the service life of the components.
[0027] This invention provides an improved high-power alloy resistor with a matching heat sink. The efficient heat conduction and release is achieved through the combined structure of the heat sink 1, thermally conductive adhesive 2, and Kelvin shunt 3. The thermally conductive adhesive 2 eliminates air gaps at the contact surface to reduce contact thermal resistance and buffer assembly mechanical stress. Combined with the heat sink 1's heat dissipation fins for convection heat dissipation, terminal avoidance, and positioning hole clamping force transmission design, the operating temperature rise of the Kelvin shunt 3 is effectively suppressed, resistance drift caused by high temperature is reduced, terminal deformation under pressure is avoided, current sampling and measurement accuracy under high current conditions is ensured, and the service life of the overall component is extended.
[0028] The above description shows and illustrates the basic principles, main features, and advantages of the present invention. Standard parts used in the present invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts, and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.
[0029] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A high-power alloy resistor with a matching heat sink, characterized in that: The device includes a heat sink (1), which is attached and fixed to the upper surface of a Kelvin shunt (3) by thermally conductive adhesive (2). The lower surface of the heat sink (1) is provided with a flat bonding plane. The outline dimensions of the bonding plane match the outline of the heating area on the upper surface of the Kelvin shunt (3). The thermally conductive adhesive (2) completely fills the space between the bonding plane of the heat sink (1) and the upper surface of the Kelvin shunt (3). The thermally conductive adhesive (2) has no local missing adhesive or air bubbles.
2. The high-power alloy resistor with a matching heat sink according to claim 1, characterized in that: The Kelvin shunt (3) includes an alloy resistor substrate and four sets of independent terminals, which are divided into two sets of current input / output terminals and two sets of voltage sampling terminals.
3. The high-power alloy resistor with a matching heat sink according to claim 2, characterized in that: The edge of the radiator (1) is turned inward to avoid the four independent terminals of the Kelvin shunt (3), and the radiator (1) does not make physical contact with the four independent terminals.
4. The high-power alloy resistor with a matching heat sink according to claim 3, characterized in that: The upper surface of the radiator (1) is integrally formed with multiple parallel heat dissipation ribs, which are evenly arranged along the length of the radiator (1) to increase the heat exchange area with the air.
5. The high-power alloy resistor with a matching heat sink according to claim 4, characterized in that: The thermally conductive adhesive (2) is made of a highly thermally conductive soft gel material. The thermally conductive adhesive (2) has a uniform thickness and buffers the mechanical stress generated during the assembly between the heat sink (1) and the Kelvin shunt (3).
6. The high-power alloy resistor with a matching heat sink according to claim 5, characterized in that: The upper surface of the alloy resistor substrate of the Kelvin shunt (3) is an exposed metal surface without insulation coverage. The exposed metal surface is in close contact with the thermally conductive adhesive (2) to achieve heat conduction.
7. The high-power alloy resistor with a matching heat sink according to claim 6, characterized in that: The radiator (1) is made of aluminum alloy and the radiator (1) is anodized. Except for the lower surface of the radiator (1), the other outer surfaces are covered with an oxide protective layer.
8. The high-power alloy resistor with a matching heat sink according to claim 7, characterized in that: The radiator (1) has positioning holes on both sides for fasteners to be inserted. The fasteners only press the radiator (1) together, and the pressure is evenly transmitted to the Kelvin shunt (3) through the thermally conductive adhesive (2). The fasteners do not directly contact the Kelvin shunt (3).
9. A high-power alloy resistor with a matching heat sink according to claim 8, characterized in that: The positioning hole of the radiator (1) is a countersunk hole. The countersunk part of the countersunk hole faces the upper surface of the radiator (1). The head of the fastener is completely contained inside the countersunk hole and does not protrude from the upper surface of the radiator (1).
10. A high-power alloy resistor with a matching heat sink according to claim 9, characterized in that: The thickness of the thermally conductive adhesive (2) is controlled at 0.2-0.5mm. The planar projection area of the thermally conductive adhesive (2) is smaller than the contact area of the heat sink (1). An overflow gap is reserved between the edge of the thermally conductive adhesive (2) and the edge of the contact area of the heat sink (1) to prevent the thermally conductive adhesive (2) from overflowing to the four independent terminal positions of the Kelvin shunt (3).