Low-inductive-reactance precision resistor and electronic device

Abstract

The utility model discloses a low-inductive-reactance precision resistor and an electronic device. The low-inductive-reactance precision resistor comprises a first conductive plate, a first insulating layer, a first resistor foil, a second insulating layer, a second resistor foil, a third insulating layer and a second conductive plate which are sequentially stacked together in the vertical direction. Wherein two outer end edges of the first resistance foil and the second resistance foil are welded together; the first conductive plate and the first resistance foil are respectively welded together at a first position and a second position of the first resistance foil; the second conductive plate and the second resistance foil are welded together in the middle of the second resistance foil, and the current directions in the first resistance foil and the second resistance foil are opposite.

Description

Technical Field

[0001] This utility model relates to the field of electronic technology, and in particular to a low inductive reactance precision resistor and electronic device. Background Technology

[0002] Wire-wound resistors are a type of fixed resistor, constructed by winding resistance wire around an insulating frame. The resistance wire is typically made of alloys with specific resistivity, such as nickel-chromium or manganese-copper. The insulating frame is made of materials such as ceramics, plastics, or metals coated with an insulating layer, and can be tubular, flat, or other shapes. The resistance wire can be wound once, multiple times, or using non-inductive winding methods as needed. Wire-wound resistors are mainly used in AC / DC circuits of precision instruments, telecommunications equipment, and electronic equipment for voltage division, voltage reduction, current shunt, and as load resistors.

[0003] However, traditional wire-wound resistors are unsuitable for AC current measurement due to their high inductance. While two-wire-wound resistors can reduce inductance, their manufacturing process is complex, and their high-frequency performance is limited (typically only applicable to frequencies below 100kHz). Existing coaxial resistors, although usable for high-frequency, high-current measurements (>1MHz, 100A), have high manufacturing costs, limiting their widespread application.

[0004] The above content is only used to help understand the technical solution of this utility model and does not represent an admission that the above content is prior art. Utility Model Content

[0005] The main objective of this invention is to provide a low-inductive-resistance precision resistor and electronic device, aiming to solve the aforementioned problems in the prior art.

[0006] To achieve the above objectives, this utility model provides a low-inductive-resistance precision resistor, which includes a first conductive plate, a first insulating layer, a first resistance foil, a second insulating layer, a second resistance foil, a third insulating layer, and a second conductive plate stacked sequentially in the vertical direction.

[0007] Wherein, the two outer edges of the first resistance foil and the second resistance foil are welded together; the first conductive plate is welded to the first resistance foil at a first position and a second position respectively; the second conductive plate is welded to the second resistance foil at a middle position; and the current directions in the first resistance foil and the second resistance foil are opposite.

[0008] Preferably, in the low inductive reactance precision resistor, the first position and the second position are respectively located on both sides of the center position of the first resistive foil.

[0009] Preferably, in the low-inductive precision resistor, the middle position of the second resistance foil is welded to the second conductive plate through a first welding part;

[0010] The two end edges of the first resistance foil and the second resistance foil are welded together by the second welding part and the third welding part, respectively;

[0011] The first conductive plate and the first resistive foil are welded together at the first position and the second position respectively by the fourth welding part and the fifth welding part.

[0012] Preferably, in the low inductive reactance precision resistor, the second conductive plate serves as the current input terminal, and the current flows sequentially through the second conductive plate, the first welding part, the second resistance foil, the second welding part and the third welding part, the first resistance foil, the fourth welding part and the fifth welding part, and the first conductive plate.

[0013] Preferably, in the low inductive reactance precision resistor, the thickness of the first resistive foil is H1, where 50μm≤H1≤1mm;

[0014] The thickness of the second resistive foil is H2, where 50μm≤H2≤1mm.

[0015] Preferably, in the low-inductive precision resistor, the first resistor foil is a Ni-Cr or Cu-Ni-Mn alloy;

[0016] The second resistance foil is a Ni-Cr or Cu-Ni-Mn alloy.

[0017] Preferably, in the low inductive precision resistor, the end edges of the first conductive plate and the second conductive plate extend beyond the first resistance foil and the second resistance foil.

[0018] Preferably, in the low inductive precision resistor, the first insulating layer is a polyimide or acrylic adhesive layer;

[0019] The second insulating layer is a polyimide or acrylic adhesive layer;

[0020] The third insulating layer is a polyimide or acrylic adhesive layer.

[0021] Preferably, in the low-inductive precision resistor, the first conductive plate and the second conductive plate are copper plates.

[0022] To achieve the above objectives, the present invention also provides an electronic device, which includes the aforementioned low-inductance precision resistor.

[0023] This utility model has at least the following beneficial effects:

[0024] This invention forms a stacked structure consisting of a first conductive plate, a first insulating layer, a first resistance foil, a second insulating layer, a second resistance foil, a third insulating layer, and a second conductive plate, which possesses excellent high-frequency characteristics, a low temperature coefficient, high precision, and good heat dissipation performance.

[0025] Furthermore, the low-inductance precision resistor provided by this invention is suitable for measuring high-frequency current, especially for applications up to 100MHz and hundreds of amperes, such as fast current sources, current sinks, power converters, high-frequency transmitters, switching power supplies, etc. Attached Figure Description

[0026] Figure 1 A schematic diagram of an embodiment of the low inductive reactance precision resistor provided by this utility model;

[0027] Figure 2 for Figure 1 A schematic diagram of the current flow direction in a medium-low inductive precision resistor.

[0028] Serial Number name Serial Number name 100 Low inductance precision resistor 7 Second conductive plate 1 First conductive plate 81 First Welding Section 2 First insulating layer 82 Second welding section 3 First resistance foil 83 Third Welding Section 4 Second insulating layer 84 Fourth Welding Section 5 Second resistance foil 85 Fifth Welding Section 6 Third insulating layer

[0029] The purpose, features, and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. The present utility model will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0031] In this embodiment of the invention, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0033] In this embodiment of the invention, the term "multiple" refers to two or more, and other quantifiers are similar.

[0034] In this utility model, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

[0035] This invention provides a low-inductive precision resistor. Please refer to [link / reference]. Figure 1 and Figure 2 The low-inductance precision resistor 100 includes a first conductive plate 1, a first insulating layer 2, a first resistive foil 3, a second insulating layer 4, a second resistive foil 5, a third insulating layer 6, and a second conductive plate 7, which are stacked sequentially in a vertical direction. The outer edges of the first resistive foil 3 and the second resistive foil 5 are welded together; the first conductive plate 1 and the first resistive foil 3 are welded together at a first position and a second position, respectively; the second conductive plate 7 and the second resistive foil 5 are welded together at a middle position, and the current directions in the first resistive foil 3 and the second resistive foil 5 are opposite.

[0036] Traditional wire-wound resistors are unsuitable for AC current measurement due to their high inductance. While two-wire-wound resistors can reduce inductance, their manufacturing process is complex, and their high-frequency performance is limited (typically only applicable to frequencies below 100kHz). Existing coaxial resistors, although usable for high-frequency, high-current measurements (>1MHz, 100A), have high manufacturing costs, limiting their widespread application.

[0037] This invention forms a stacked structure consisting of a first conductive plate 1, a first insulating layer 2, a first resistance foil 3, a second insulating layer 4, a second resistance foil 5, a third insulating layer 6, and a second conductive plate 7, which possesses excellent high-frequency characteristics, a low temperature coefficient, high precision, and good heat dissipation performance.

[0038] Furthermore, the low-inductance precision resistor 100 provided by this invention is suitable for measuring high-frequency current, especially for applications up to 100MHz and hundreds of amperes, such as fast current sources, current sinks, power converters, high-frequency transmitters, switching power supplies, etc.

[0039] The first resistive foil 3 and the second resistive foil 5 are used to provide resistance and form a current path with low inductive reactance. The first resistive foil 3 may be, but is not limited to, a metal alloy foil with a low temperature coefficient, such as Ni-Cr or Cu-Ni-Mn alloy; similarly, the second resistive foil 5 may be, but is not limited to, a metal alloy foil with a low temperature coefficient, such as Ni-Cr or Cu-Ni-Mn alloy, thus ensuring high stability and low temperature drift.

[0040] It is worth noting that the first resistive foil 3 and the second resistive foil 5 are arranged in a symmetrical stack, and the current flows in the first resistive foil 3 and the second resistive foil 5 are in opposite directions to cancel the inductance and reduce the high-frequency parasitic effect.

[0041] Specifically, the second resistance foil 5 is welded to the second conductive plate 7 at its middle position via a first welding part 81. The two end edges of the first resistance foil 3 and the second resistance foil 5 are welded together via a second welding part 82 and a third welding part 83, respectively. The first conductive plate 1 and the first resistance foil 3 are welded together at a first position and a second position via a fourth welding part 84 and a fifth welding part 85, respectively. The second conductive plate 7 serves as the current input terminal, and the current flows sequentially through the second conductive plate 7, the first welding part 81, the second resistance foil 5, the second welding part 82 and the third welding part 83, the first resistance foil 3, the fourth welding part 84 and the fifth welding part 85, and the first conductive plate 1. After flowing out from the first welding part 81, the current flows in the opposite direction to the second resistance foil 5; while the current flowing out from the second welding part 82 and the third welding part 83 flows along the first resistance foil 3 in opposite directions to the fourth welding part 84 and the fifth welding part 85, that is, the current flows in opposite directions in both the first resistance foil 3 and the second resistance foil 5.

[0042] In some embodiments, the first welding part 81, the second welding part 82, the third welding part 83, the fourth welding part 84, and the fifth welding part 85 can be welded using conventional welding methods. Of course, in some embodiments, the first welding part 81, the second welding part 82, the third welding part 83, the fourth welding part 84, and the fifth welding part 85 can also be welded using copper (Cu) + soft solder (PbSn) or other low-temperature solders, thus ensuring excellent electrical contact. The first welding part 81, the second welding part 82, the third welding part 83, the fourth welding part 84, and the fifth welding part 85 can form a connection area between the upper and lower edges of the first resistance foil 3 and the second resistance foil 5, respectively, and form an electrical connection with the first conductive plate 1 and the second conductive plate 7.

[0043] The first and second positions can be set as needed. In some embodiments, the first and second positions are respectively located symmetrically on both sides of the center of the first resistive foil 3. The symmetrical positions of the first and second positions can be adjusted as needed to change the current flow path and thus change the resistance value, thereby achieving resistance adjustment through process quantification.

[0044] In some embodiments, the thickness of the first resistive foil 3 is H1, 50μm≤H1≤1mm; and the thickness of the second resistive foil 5 is H2, 50μm≤H2≤1mm. In other embodiments, the thickness of the first resistive foil 3 and the thickness of the second resistive foil 5 can be selected based on the target resistance value.

[0045] The first conductive plate 1 and the second conductive plate 7 are typically made of conductive metals. In some embodiments, the first conductive plate 1 and the second conductive plate 7 can also be made of metals that are both conductive and thermally conductive, such as copper. Generally, without considering cost, the first conductive plate 1 and the second conductive plate 7 can be made of metals with better electrical and thermal conductivity, which is more effective in reducing contact resistance and optimizing heat dissipation.

[0046] The first conductive plate 1 and the second conductive plate 7 primarily serve as supports and dissipate heat. The thickness of the first conductive plate 1 and the second conductive plate 7 can be selected to be several millimeters, providing multiple functions such as mechanical support, heat dissipation, and electrical shielding. In some embodiments, the edges of the first conductive plate 1 and the second conductive plate 7 extend beyond the first resistive foil 3 and the second resistive foil 5, thus facilitating the connection to external current paths.

[0047] Furthermore, the first conductive plate 1 and the second conductive plate 7 can serve as high-current input terminals to achieve low-resistance, high-conductivity current transmission. In some embodiments, the first conductive plate 1 and the second conductive plate 7 can serve as mechanically fixed resistor foils to prevent deformation under stress and improve stability; in other embodiments, the first conductive plate 1 and the second conductive plate 7 can also serve as heat sinks to optimize thermal management and prevent resistor overheating and drift.

[0048] The first insulating layer 2 may be, but is not limited to, a polyimide or acrylic adhesive layer. Similarly, the second insulating layer 4 is a polyimide or acrylic adhesive layer. The third insulating layer 6 is a polyimide or acrylic adhesive layer. In some other embodiments, the first insulating layer 2, the second insulating layer 4, and the third insulating layer 6 may also be other high-temperature resistant and mechanically stable insulating materials.

[0049] The first insulating layer 2 ensures electrical isolation between the first conductive plate 1 and the first resistance foil 3, and also fixes the first conductive layer and the first resistance foil 3. The second insulating layer 4 ensures electrical isolation between the first resistance foil 3 and the second resistance foil 5, and also fixes the first resistance foil 3 and the second resistance foil 5. The third insulating layer 6 ensures electrical isolation between the second conductive plate 7 and the second resistance foil 5, and also fixes the second conductive layer and the second resistance foil 5.

[0050] By setting the first insulating layer 2, the second insulating layer 4, and the third insulating layer 6, electrical isolation can be formed between each resistor foil and the conductive plate to prevent short circuits; in addition, mechanical stability can be provided to avoid interlayer peeling or displacement.

[0051] In current path measurements, especially high-frequency power measurements, the measuring current enters from the second conductive plate 7, passes through the first welding part 81, and enters the second resistance foil 5. The current flows in both directions through the second resistance foil 5, passing through the second welding part 82 and the third welding part 83 into the first resistance foil 3, and then flows into the first conductive plate 1 in opposite directions through the fourth welding part 84 and the fifth welding part 85, respectively. The measuring current finally flows out from the first conductive plate 1, completing the measurement circuit. Because the current flows in opposite directions through the two resistance foils, a low inductive reactance structure is formed, making it suitable for high-frequency measurements.

[0052] When performing voltage measurements, four terminals can be set on the first conductive plate 1 and the second conductive plate 7 to detect the voltage drop across the two resistive foils, forming a Kelvin four-terminal measurement to ensure measurement accuracy.

[0053] Because the current flows in opposite directions in the first resistive foil 3 and the second resistive foil 5, the magnetic fields they generate cancel each other out, thereby greatly reducing parasitic inductance and making it suitable for high-frequency current measurement up to 100MHz. The first conductive plate 1 and the second conductive plate 7 act as heat sinks, allowing the heat generated by the first resistive foil 3 and the second resistive foil 5 to be quickly conducted away, improving the power load capacity and long-term stability of the resistor.

[0054] This invention also provides an electronic device comprising the aforementioned low-inductive-resistance precision resistor 100. Embodiments of this electronic device include embodiments of the aforementioned low-inductive-resistance precision resistor 100; the beneficial effects of the aforementioned low-inductive-resistance precision resistor 100 can be applied to this electronic device.

[0055] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, those skilled in the art can make other variations or modifications without creative effort, and all such variations or modifications should fall within the protection scope of this utility model.

Claims

1. A low inductive precision resistor, characterized by, It includes a first conductive plate, a first insulating layer, a first resistance foil, a second insulating layer, a second resistance foil, a third insulating layer, and a second conductive plate, which are stacked sequentially in the vertical direction. Wherein, the two outer edges of the first resistance foil and the second resistance foil are welded together; the first conductive plate is welded to the first resistance foil at a first position and a second position respectively; the second conductive plate is welded to the second resistance foil at a middle position; and the current directions in the first resistance foil and the second resistance foil are opposite.

2. The low inductive precision resistor of claim 1, wherein, The first position and the second position are respectively located on both sides of the center position of the first resistive foil.

3. The low inductive precision resistor of claim 2, wherein, The second resistance foil is welded to the second conductive plate at its middle position via the first welding part; The two end edges of the first resistance foil and the second resistance foil are welded together by the second welding part and the third welding part, respectively; The first conductive plate and the first resistive foil are welded together at the first position and the second position respectively by the fourth welding part and the fifth welding part.

4. The low inductive precision resistor of claim 3, wherein, The second conductive plate serves as the current input terminal, and the current flows sequentially through the second conductive plate, the first welding part, the second resistance foil, the second welding part and the third welding part, the first resistance foil, the fourth welding part and the fifth welding part, and the first conductive plate.

5. The low inductive precision resistor of claim 1, wherein, The thickness of the first resistive foil is H1, where 50μm≤H1≤1mm; The thickness of the second resistive foil is H2, where 50μm≤H2≤1mm.

6. The low inductive precision resistor of claim 1, wherein, The first resistance foil is a Ni-Cr or Cu-Ni-Mn alloy; The second resistance foil is a Ni-Cr or Cu-Ni-Mn alloy.

7. The low inductive precision resistor of claim 1, wherein The end edges of the first conductive plate and the second conductive plate extend beyond the first resistance foil and the second resistance foil, respectively.

8. The low inductive precision resistor of claim 1, wherein, The first insulating layer is a polyimide or acrylic adhesive layer; The second insulating layer is a polyimide or acrylic adhesive layer; The third insulating layer is a polyimide or acrylic adhesive layer.

9. The low inductive precision resistor of claim 1, wherein, The first conductive plate and the second conductive plate are copper plates.

10. An electronic device, characterized by Including the low inductive precision resistor as described in any one of claims 1 to 9.

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