Current sensing resistor with low temperature coefficient of resistance and method of manufacturing the same

Abstract

A low temperature coefficient of resistance current sense resistor and a method of manufacturing the same. The low temperature coefficient of resistance current sense resistor includes a negative temperature coefficient of resistance substrate, a resistance layer disposed on the negative temperature coefficient of resistance substrate, and a first end electrode and a second end electrode. In the method of manufacturing the low temperature coefficient of resistance current sense resistor, a negative temperature coefficient of resistance substrate is provided first. Then, a resistance layer is formed on the negative temperature coefficient of resistance substrate to provide a body, wherein the body includes the negative temperature coefficient of resistance substrate and the resistance layer, and has a first end portion and a second end portion opposite to the first end portion. Next, a first end electrode is formed on the first end portion of the body, and a second end electrode is formed on the second end portion of the body. In this way, the negative temperature coefficient of resistance substrate can be used to reduce the temperature coefficient of resistance.

Description

Technical Field

[0001] This invention relates to a current sensing resistor with a low temperature coefficient of resistance and a method for manufacturing the same. Background Technology

[0002] In existing resistor manufacturing methods, an insulating ceramic substrate or a flexible material is first used as an additional carrier plate. Then, a printing process or a physical vapor deposition process is used to deposit the selected resistive material on the surface of the additional carrier plate. Finally, terminal electrodes are formed at both ends of the resistive material to make a resistor.

[0003] The temperature coefficient of resistance (TCR) of resistors manufactured using the above-described resistor manufacturing method is mainly determined by the selected resistive material and terminal electrode material. However, since both the resistive material and the terminal electrode material have positive temperature coefficients, it is difficult to design resistors with low temperature coefficients of resistance. Summary of the Invention

[0004] The present invention provides a current sensing resistor with a low temperature coefficient of resistance and a method for manufacturing the same, which uses a resistive substrate with a negative temperature coefficient (NTC) to effectively reduce the temperature coefficient of resistance of the current sensing resistor.

[0005] According to an embodiment of the present invention, the aforementioned low temperature coefficient current sensing resistor comprises: a negative temperature coefficient resistive substrate, a resistive layer, a first terminal electrode, and a second terminal electrode. The resistive layer is disposed on the negative temperature coefficient resistive substrate to form a main body, the main body having a first end and a second end, the first end and the second end being opposite to each other. The first terminal electrode is disposed on the first end of the main body, and the second terminal electrode is disposed on the second end of the main body.

[0006] In some embodiments, a first end electrode covers a first end of the body, and a second end electrode covers a second end of the body.

[0007] In some embodiments, the first end electrode includes a first upper electrode, a first lower electrode, and a first side electrode. The first upper electrode is disposed on the upper surface of the body, the first lower electrode is disposed on the lower surface of the body, and the first side electrode extends to be disposed on the first upper electrode, the first lower electrode, and the first side surface of the body. The second end electrode includes a second upper electrode, a second lower electrode, and a second side electrode. The second upper electrode is disposed on the upper surface of the body, the second lower electrode is disposed on the lower surface of the body, and the second side electrode extends to be disposed on the second upper electrode, the second lower electrode, and the second side surface of the body. The lower surface of the body is relative to the upper surface of the body, and the second side surface of the body is relative to the first side surface of the body.

[0008] In some embodiments, the current sensing resistor further includes a first insulating layer and a second insulating layer. The first insulating layer is disposed on the upper surface of the negative temperature coefficient resistive substrate and is located between the negative temperature coefficient resistive substrate and the resistive layer. The second insulating layer is disposed on the lower surface of the negative temperature coefficient resistive substrate. The lower surface of the negative temperature coefficient resistive substrate is relative to the upper surface of the negative temperature coefficient resistive substrate.

[0009] In some embodiments, the first insulating layer and the second insulating layer are made of glass.

[0010] In some embodiments, the negative temperature coefficient resistive substrate and the resistive layer are electrically connected in parallel.

[0011] According to another embodiment of the present invention, the method for manufacturing the low temperature coefficient current sensing resistor described above includes: providing a negative temperature coefficient resistive substrate; forming a resistive layer on the negative temperature coefficient resistive substrate to provide a body, wherein the body includes the negative temperature coefficient resistive substrate and the resistive layer, and has a first end and a second end, the first end and the second end being opposite to each other; forming a first end electrode on the first end of the body; and forming a second end electrode on the second end of the body.

[0012] In some embodiments, the step of forming a resistive layer on a negative temperature coefficient resistive substrate is performed by printing or coating.

[0013] In some embodiments, the method for manufacturing the low temperature coefficient current sensing resistor further includes: forming a first insulating layer on the upper surface of the negative temperature coefficient resistive substrate; and forming a second insulating layer on the lower surface of the negative temperature coefficient resistive substrate. The first insulating layer is located between the negative temperature coefficient resistive substrate and the resistive layer, with the upper surface of the negative temperature coefficient resistive substrate relative to the lower surface of the negative temperature coefficient resistive substrate.

[0014] In some embodiments, the first insulating layer and the second insulating layer are made of glass.

[0015] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings. Attached Figure Description

[0016] Figure 1 A schematic diagram illustrating the structure of a current sensing resistor with a low resistance temperature coefficient according to an embodiment of the present invention is provided.

[0017] Figure 2 This is a schematic flowchart illustrating a method for manufacturing a current sensing resistor with a low resistance temperature coefficient according to an embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram illustrating the structure of a current sensing resistor according to an embodiment of the present invention, corresponding to an intermediate stage of the manufacturing method described above.

[0019] Figure 4 A schematic diagram illustrating the structure of a current sensing resistor with a low resistance temperature coefficient according to an embodiment of the present invention is provided.

[0020] Figure 5 A schematic diagram of the equivalent circuit of a current sensing resistor according to an embodiment of the present invention is provided.

[0021] Figure 6 This is a schematic diagram illustrating the structure of a current sensing resistor according to an embodiment of the present invention, corresponding to an intermediate stage of the manufacturing method described above.

[0022] Figure 7 A schematic diagram illustrating the structure of a current sensing resistor with a low resistance temperature coefficient according to an embodiment of the present invention is provided. Detailed Implementation

[0023] The following is a detailed description of the embodiments in conjunction with the accompanying drawings. However, the embodiments provided are not intended to limit the scope of the invention, and the description of the structural operation is not intended to limit the order of execution. Any structure resulting from the recombination of elements and producing a device with equivalent functionality is within the scope of the invention. Furthermore, the accompanying drawings are for illustrative purposes only and are not drawn to their original dimensions.

[0024] The terms "first," "second," etc., used in this article do not specifically refer to order or sequence; they are merely used to distinguish elements or operations described using the same technical terms.

[0025] Please refer to Figure 1This is a schematic diagram illustrating the structure of a low temperature coefficient current sensing resistor 100 according to an embodiment of the present invention. The current sensing resistor 100 includes a negative temperature coefficient (NTC) resistive substrate 110, a resistive layer 120, a first terminal electrode 131, a second terminal electrode 132, a first protective layer 140, and a second protective layer 150. The NTC resistive substrate 110 is made of a material whose resistance decreases as the temperature rises. In this embodiment, the material of the NTC resistive substrate 110 may be a ceramic oxide such as manganese (Mn), nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn), chromium (Cr), aluminum (Al), and silicon (Si), or a sinterable glass-related material containing silicon (Si), bismuth (Bi), boron (B), magnesium (Mg), calcium (Ca), titanium (Ti), and lead (Pb), but the embodiments of the present invention are not limited to these. The resistive layer 120 is disposed on the NTC resistive substrate 110 to provide the resistance value required by the user. In this embodiment, the material of the resistive layer 120 includes silver-copper alloy, nickel-chromium-copper alloy, nickel-chromium-silicon alloy, manganese-copper alloy, or nickel-copper alloy, but the embodiments of the present invention are not limited to these. Furthermore, the resistive layer 120 in the embodiments of the present invention is a resistive material with a positive temperature coefficient.

[0026] The first end electrode 131 and the second end electrode 132 are respectively disposed at both ends of the negative temperature coefficient resistive substrate 110 / resistive layer 120 to provide circuit contacts for the current sensing resistor 100. In this embodiment, the first end electrode 131 includes a first upper electrode 131a, a first lower electrode 131b, and a first side electrode 131c, while the second end electrode 132 includes a second upper electrode 132a, a second lower electrode 132b, and a second side electrode 132c. The first upper electrode 131a and the second upper electrode 132a are disposed on the upper surface of the resistive layer 120 and are located at opposite ends of the resistive layer 120. The first lower electrode 131b and the second lower electrode 132b are disposed on the lower surface of the negative temperature coefficient resistive substrate 110 and are located at opposite ends of the negative temperature coefficient resistive substrate 110. In some embodiments, the first upper electrode 131a and the second upper electrode 132a are aligned with the first lower electrode 131b and the second lower electrode 132b, but the embodiments of the present invention are not limited thereto.

[0027] A first side electrode 131c extends from and is disposed on the side surfaces of the first upper electrode 131a, the first lower electrode 131b, the negative temperature coefficient resistor substrate 110, and the resistor layer 120. Specifically, one end of the first side electrode 131c is disposed on the first upper electrode 131a, and sequentially extends along the side surfaces of the resistor layer 120 and the negative temperature coefficient resistor substrate 110 to the first lower electrode 131b, such that the other end of the first side electrode 131c is disposed on the first lower electrode 131b. Similarly, a second side electrode 132c extends from and is disposed on the side surfaces of the second upper electrode 132a, the second lower electrode 132b, the negative temperature coefficient resistor substrate 110, and the resistor layer 120. Specifically, one end of the second side electrode 132c is disposed on the second upper electrode 132a, and sequentially extends along the other side surfaces of the resistor layer 120 and the negative temperature coefficient resistor substrate 110 to the second lower electrode 132b, such that the other end of the second side electrode 132c is disposed on the second lower electrode 132b.

[0028] A first protective layer 140 is disposed on the resistive layer 120 and located between the first upper electrode 131a and the second upper electrode 132a to cover the exposed portion of the resistive layer 120, thereby protecting the resistive layer 120. A second protective layer 150 is disposed on the first protective layer 140 and covers the first protective layer 140 and a portion of the first upper electrode 131a and the second upper electrode 132a to further protect the resistive layer 120. The first protective layer 140 and the second protective layer 150 prevent, for example, the resistive layer 120 from contact with external air and from being corroded by moisture. In this embodiment, the materials of the first protective layer 140 and the second protective layer 150 may be ink, polyimide film, or solder resist photoresist, but the embodiments of the present invention are not limited to these.

[0029] As can be seen from the above description, the current sensing resistor 100 of the present invention is made of a substrate with a negative temperature coefficient (i.e., negative temperature coefficient resistor substrate 110). Therefore, when the temperature of the current sensing resistor 100 rises, the negative temperature coefficient resistor substrate 110 can be used to provide compensation, so that the resistance of the current sensing resistor 100 does not rise significantly with the temperature, thereby providing a current sensing resistor with a low resistance temperature coefficient.

[0030] Please refer to the following at the same time Figure 2 and Figure 3 , Figure 2 A flowchart illustrating a method 200 for manufacturing a low-resistance temperature coefficient current sensing resistor according to an embodiment of the present invention is provided. Figure 3The diagram illustrates a current-sensing resistor according to an embodiment of the present invention, corresponding to an intermediate stage of the manufacturing method 200 described above. In manufacturing method 200, step 210 is first performed to provide the aforementioned negative temperature coefficient resistive substrate 110. Then, step 220 is performed to form the aforementioned resistive layer 120 on the negative temperature coefficient resistive substrate 110, thereby serving as the body 300 of the resistor. In this embodiment, the resistive layer 120 is formed on the negative temperature coefficient resistive substrate 110 by printing or physical vapor deposition, but embodiments of the present invention are not limited to this. Next, step 230 is performed to form terminal electrodes and a protective layer on the body 300. For example, a first upper electrode 131a and a second upper electrode 132a are first formed on opposite ends of the resistive layer 120, and a first lower electrode 131b and a second lower electrode 132b are formed on opposite ends of the negative temperature coefficient resistive substrate 110, and then a first side electrode 131c, a second side electrode 132c, a first protective layer 140 and a second protective layer 150 are formed on the main body 300.

[0031] Please refer to Figure 4 This is a schematic diagram illustrating the structure of a low temperature coefficient current sensing resistor 400 according to an embodiment of the present invention. The current sensing resistor 400 includes a negative temperature coefficient resistive substrate 410, a resistive layer 420, a first terminal electrode 431, a second terminal electrode 432, a first protective layer 440, a second protective layer 450, a first insulating layer 460, and a second insulating layer 470. The negative temperature coefficient resistive substrate 410 is made of a material whose resistance decreases as the temperature rises. In this embodiment, the material of the negative temperature coefficient resistive substrate 410 may be a ceramic oxide such as manganese (Mn), nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn), chromium (Cr), aluminum (Al), and silicon (Si), or a sinterable glass-related material containing silicon (Si), bismuth (Bi), boron (B), magnesium (Mg), calcium (Ca), titanium (Ti), and lead (Pb), but the embodiments of the present invention are not limited thereto.

[0032] The first insulating layer 460 and the second insulating layer 470 are respectively disposed on the upper and lower surfaces of the negative temperature coefficient resistive substrate 410 to provide electrical isolation. In this embodiment, the first insulating layer 460 and the second insulating layer 470 are made of glass, but the embodiments of the present invention are not limited thereto.

[0033] A resistive layer 420 is disposed on the first insulating layer 460 to provide the resistance value required by the user. In this embodiment, the material of the resistive layer 420 is similar to that of the resistive layer 120 described above, and includes silver-copper alloy, nickel-chromium-copper alloy, nickel-chromium-silicon alloy, manganese-copper alloy, or nickel-copper alloy, but the embodiments of the present invention are not limited thereto. In addition, the resistive layer 420 of the embodiments of the present invention is also a resistive material with a positive temperature coefficient.

[0034] The first terminal electrode 431 and the second terminal electrode 432 are respectively disposed at both ends of the second insulating layer 470 / resistive layer 420 to provide circuit contacts for the current sensing resistor 400. In this embodiment, the first terminal electrode 431 includes a first upper electrode 431a, a first lower electrode 431b, and a first side electrode 431c, while the second terminal electrode 432 includes a second upper electrode 432a, a second lower electrode 432b, and a second side electrode 432c. The first upper electrode 431a and the second upper electrode 432a are disposed on the resistive layer 420 and located at opposite ends of the first insulating layer 460. The first lower electrode 431b and the second lower electrode 432b are disposed on the lower surface of the second insulating layer 470 and located at opposite ends of the second insulating layer 470. In some embodiments, the first upper electrode 431a and the second upper electrode 432a are aligned with the first lower electrode 431b and the second lower electrode 432b, but the embodiments of the present invention are not limited thereto.

[0035] The first side electrode 431c extends and is disposed on the side surfaces of the first upper electrode 431a, the first lower electrode 431b, the negative temperature coefficient resistive substrate 410, the resistive layer 420, and the first insulating layer 460 and the second insulating layer 470. Specifically, one end of the first side electrode 431c is disposed on the first upper electrode 431a, and extends sequentially along the side surfaces of the resistive layer 420, the first insulating layer 460, the negative temperature coefficient resistive substrate 410, and the second insulating layer 470 to the first lower electrode 431b, such that the other end of the first side electrode 431c is disposed on the first lower electrode 431b.

[0036] Similarly, the second side electrode 432c extends onto the side surfaces of the second upper electrode 432a, the second lower electrode 432b, the resistive layer 420 of the negative temperature coefficient resistive substrate 410, and the first insulating layer 460 and the second insulating layer 470. Specifically, one end of the second side electrode 432c is disposed on the second upper electrode 432a, and extends sequentially along the side surfaces of the resistive layer 420, the first insulating layer 460, the negative temperature coefficient resistive substrate 410, and the second insulating layer 470 to the second lower electrode 432b, such that the other end of the second side electrode 432c is disposed on the second lower electrode 432b.

[0037] A first protective layer 440 is disposed on the resistive layer 420 and located between the first upper electrode 431a and the second upper electrode 432a to cover the exposed portion of the resistive layer 420, thereby protecting the resistive layer 420. A second protective layer 450 is disposed on the first protective layer 440 and covers the first protective layer 440 and a portion of the first upper electrode 431a and the second upper electrode 432a to further protect the resistive layer 420. The first protective layer 440 and the second protective layer 450 prevent, for example, the resistive layer 420 from contact with external air and from being corroded by moisture. In this embodiment, the materials of the first protective layer 440 and the second protective layer 450 may be ink, polyimide film, or solder resist photoresist, but the embodiments of the present invention are not limited to these.

[0038] Please refer to Figure 5 This is a schematic diagram illustrating the equivalent circuit of the current sensing resistor 400 according to an embodiment of the present invention, where resistor 420R represents the resistance of the resistive layer 420, and resistor 410R represents the resistance of the negative temperature coefficient resistive substrate 410. Figure 5 It is known that the resistor 420R of the resistive layer 420 is electrically connected in parallel with the resistor 410R of the negative temperature coefficient resistive substrate 410. When the temperature of the current sensing resistor 400 rises, although the resistance of the resistor 420R of the resistive layer 420 also rises, the resistance of the negative temperature coefficient resistive substrate 410R decreases. Thus, the resistance 410R of the negative temperature coefficient resistive substrate 410 can be used to provide compensation, so that the resistance of the current sensing resistor 400 does not rise significantly with the temperature, thereby providing a current sensing resistor with a low resistance temperature coefficient.

[0039] Please refer to the following at the same time Figure 6 and Figure 7 , Figure 6 A flowchart illustrating a method 600 for manufacturing a low-resistance temperature coefficient current sensing resistor according to an embodiment of the present invention is provided. Figure 7This is a schematic diagram illustrating the structure of a current-sensing resistor according to an embodiment of the present invention, corresponding to an intermediate stage of the manufacturing method 600 described above. In manufacturing method 600, step 610 is first performed to provide the aforementioned negative temperature coefficient resistive substrate 410. Then, step 620 is performed to form the aforementioned first insulating layer 460 and second insulating layer 470 on the upper and lower surfaces of the negative temperature coefficient resistive substrate 410, respectively. Next, step 630 is performed to form the aforementioned resistive layer 420 on the first insulating layer 460, thereby forming the body 700 of the resistor. Then, step 640 is performed to form terminal electrodes and a protective layer on the body 700. For example, a first upper electrode 431a and a second upper electrode 432a are first formed on opposite ends of the resistive layer 420, and a first lower electrode 431b and a second lower electrode 432b are formed on opposite ends of the second insulating layer 470. Then, a first side electrode 431c, a second side electrode 432c, a first protective layer 440, and a second protective layer 450 are formed on the main body 700.

[0040] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

[0041] [Symbol Explanation]

[0042] 100: Current sensing resistor

[0043] 110: Negative temperature coefficient resistor substrate

[0044] 120: Resistive layer

[0045] 131: First terminal electrode

[0046] 131a: First upper electrode

[0047] 131b: First lower electrode

[0048] 131c: First side electrode

[0049] 132: Second terminal electrode

[0050] 132a: Second upper electrode

[0051] 132b: Second lower electrode

[0052] 132c: Second side electrode

[0053] 140: First protective layer

[0054] 150: Second protective layer

[0055] 200: Manufacturing method of current sensing resistor

[0056] 210~230: Steps

[0057] 300: Main Body

[0058] 400: Current sensing resistor

[0059] 410: Negative temperature coefficient resistor substrate

[0060] 420: Resistive layer

[0061] 431: First terminal electrode

[0062] 431a: First upper electrode

[0063] 431b: First lower electrode

[0064] 431c: First side electrode

[0065] 432: Second terminal electrode

[0066] 432a: Second upper electrode

[0067] 432b: Second lower electrode

[0068] 432c: Second side electrode

[0069] 440: First protective layer

[0070] 450: Second protective layer

[0071] 460: First insulating layer

[0072] 470: Second insulating layer

[0073] 410R: Resistor

[0074] 420R: Resistor

[0075] 600: Manufacturing method of current sensing resistor

[0076] 610~640: Steps

[0077] 700: Main body.

Claims

1. A current sensing resistor with a low temperature coefficient of resistance, characterized in that... Include: Negative temperature coefficient resistor substrate; A resistive layer is disposed on the negative temperature coefficient resistive substrate to form a main body with the negative temperature coefficient resistive substrate. The main body has a first end and a second end, with the first end and the second end facing each other. A first end electrode is disposed on the first end of the main body; The second electrode is disposed on the second end of the main body; A first insulating layer is disposed on the upper surface of the negative temperature coefficient resistor substrate and is located between the negative temperature coefficient resistor substrate and the resistor layer. as well as A second insulating layer is disposed on the lower surface of the negative temperature coefficient resistor substrate, wherein the lower surface of the negative temperature coefficient resistor substrate is relative to the upper surface of the negative temperature coefficient resistor substrate.

2. The low temperature coefficient current sensing resistor according to claim 1, characterized in that... The first end electrode covers the first end of the body, and the second end electrode covers the second end of the body.

3. The low temperature coefficient current sensing resistor according to claim 2, characterized in that... The first end electrode includes a first upper electrode, a first lower electrode, and a first side electrode. The first upper electrode is disposed on the upper surface of the main body, the first lower electrode is disposed on the lower surface of the main body, and the first side electrode extends to the first upper electrode, the first lower electrode, and the first side surface of the main body. The second end electrode includes a second upper electrode, a second lower electrode, and a second side electrode. The second upper electrode is disposed on the upper surface of the main body, the second lower electrode is disposed on the lower surface of the main body, and the second side electrode extends to the second upper electrode, the second lower electrode, and the second side surface of the main body. The lower surface of the main body is relative to the upper surface of the main body, and the second side surface of the main body is relative to the first side surface of the main body.

4. The low temperature coefficient current sensing resistor according to claim 1, characterized in that... The first insulating layer and the second insulating layer are made of glass.

5. The low temperature coefficient current sensing resistor according to claim 1, characterized in that... The negative temperature coefficient resistive substrate is electrically connected in parallel with the resistive layer.

6. A method for manufacturing a current sensing resistor with a low temperature coefficient of resistance, characterized in that... Include: Provides negative temperature coefficient resistor substrates; A resistive layer is formed on the negative temperature coefficient resistive substrate to provide a body, wherein the body includes the negative temperature coefficient resistive substrate and the resistive layer, and has a first end and a second end, the first end being opposite to the second end; A first end electrode is formed on the first end of the body; A second end electrode is formed on the second end of the body. A first insulating layer is formed on the upper surface of the negative temperature coefficient resistive substrate; as well as A second insulating layer is formed on the lower surface of the negative temperature coefficient resistive substrate; In this configuration, the upper surface of the negative temperature coefficient resistor substrate is relative to the lower surface of the negative temperature coefficient resistor substrate, and the first insulating layer is located between the negative temperature coefficient resistor substrate and the resistor layer.

7. The method for manufacturing a low temperature coefficient current sensing resistor according to claim 6, characterized in that... The step of forming the resistive layer on the negative temperature coefficient resistive substrate is performed by printing or coating.

8. The method for manufacturing a low-resistance temperature coefficient current sensing resistor according to claim 6, characterized in that... The first insulating layer and the second insulating layer are made of glass.

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