High-temperature-resistant chip resistor
By adopting a specific structure and material combination in the chip resistor, the problem of insufficient heat dissipation at high temperatures is solved, and the stable operation of higher temperature and high power is achieved, which improves the high temperature resistance and high power performance of the resistor.
Patent Information
- Application Number
- CN202422112360.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2025-08-05
- Estimated Expiration
- 2034-08-29
AI Technical Summary
Existing chip resistors have insufficient heat dissipation performance under high temperature or high power conditions, limiting their application range.
A high-temperature resistant chip resistor is designed, using a specific structure and material combination, including a special layout of rectangular substrate, back electrodes and resistors, adding heat dissipation paths, and using highly thermally conductive materials and protective layers to improve heat dissipation capabilities.
It improves the high temperature and high power performance of the resistor, enables it to operate stably at higher ambient temperatures, enhances the anti-vulcanization and surge resistance, and improves the rated power.
Smart Images
Figure CN223193593U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of resistors, in particular to a high-temperature resistant chip resistor. Background Art
[0002] The characteristics of chip resistors are mainly generated by the resistor body. The high temperature resistance of the resistor body can reach above 200℃. However, it is subject to the influence of the materials and design of the bonding layers and structural layers. Under high temperature or high power conditions, the heat of the resistor body cannot be dissipated in time. As a result, the high temperature and high power performance of ordinary chip resistors are insufficient. They can only be used at an ambient temperature of 70℃, which seriously limits the application of chip resistors.
[0003] Therefore, there is an urgent need for a high temperature resistant chip resistor to solve the above problems. Utility Model Content
[0004] The purpose of the utility model is to provide a high temperature resistant chip resistor to improve the heat dissipation performance of the chip resistor.
[0005] To achieve this purpose, the present invention adopts the following technical solutions:
[0006] A high temperature resistant chip resistor, comprising:
[0007] substrate;
[0008] A front electrode, comprising a first front electrode and a second front electrode, wherein the first front electrode and the second front electrode are both disposed on the upper surface of the substrate and are respectively located at two ends of the substrate along a first direction, where the first direction is the length direction of the substrate;
[0009] A resistor is provided on the upper surface of the substrate, the resistor is connected to the first front electrode and the second front electrode, the resistor is provided in the middle of the substrate along the first direction, and the length of the resistor along the first direction is greater than 1 / 3 of the length of the substrate;
[0010] a back electrode, comprising a first back electrode and a second back electrode, wherein the first back electrode and the second back electrode are both disposed on the lower surface of the substrate and are respectively located at both ends of the substrate along the first direction, the length of the first back electrode along the first direction is not less than 1 / 3 of the length of the substrate, and the length of the second back electrode along the first direction is not less than 1 / 3 of the length of the substrate;
[0011] The end electrode includes a first end electrode and a second end electrode, the first end electrode is provided at one end of the substrate along the first direction, and the second end electrode is provided at the other end of the substrate along the first direction, the first end electrode connects the first front electrode and the first back electrode, and the second end electrode connects the second front electrode and the second back electrode.
[0012] As an improvement of the above technical solution, a resistance repair groove is provided on the resistor body, and the first end of the resistance repair groove along the second direction extends to the end face of the first end of the resistor body along the second direction, and the length of the resistance repair groove along the second direction is not greater than 1 / 4 of the length of the resistor body along the second direction, and the second direction is the width direction of the substrate.
[0013] As an improvement of the above technical solution, the resistor covers a partial area of the first front electrode and a partial area of the second front electrode.
[0014] As an improvement of the above technical solution, it further includes an inner protective layer, which covers at least a partial area of the resistor body.
[0015] As an improvement to the above technical solution, it further includes a heat insulation layer, which covers the inner protective layer and the area of the resistor body exposed from the inner protective layer.
[0016] As an improvement of the above technical solution, it also includes an outer protective layer, which covers the thermal insulation layer.
[0017] As an improvement of the above technical solution, it further includes an electroplated nickel layer, and the end electrode, the back electrode and the area of the front electrode exposed from the outer protective layer are all covered with the electroplated nickel layer.
[0018] As an improvement of the above technical solution, it also includes an electroplated tin layer, and the outer surface of the electroplated nickel layer is covered with the electroplated tin layer.
[0019] As an improvement to the above technical solution, the inner protective layer is made of a bismuth-free and lead-containing material.
[0020] As an improvement of the above technical solution, the front electrode adopts a silver-palladium electrode paste material containing a palladium content of not less than 10%.
[0021] Compared with the prior art, the present invention has the following beneficial effects:
[0022] In the high-temperature resistant chip resistor of the present invention, the lengths of the first back electrode and the second back electrode along the first direction are not less than 1 / 3 of the length of the substrate, the resistor body is arranged in the middle of the substrate along the first direction, and the length of the resistor body along the first direction is greater than 1 / 3 of the length of the substrate, so that the ends of the first back electrode and the second back electrode close to each other can extend to directly below the resistor body, thereby accelerating the heat generated by the resistor body to be transferred to the first back electrode and the second back electrode through the substrate as soon as possible, and dissipating downward through the first back electrode and the second back electrode to the soldering pad of the high-temperature resistant chip resistor, so as to improve the heat dissipation capacity of the high-temperature resistant chip resistor, thereby improving the high-temperature resistance and high-power performance of the high-temperature resistant chip resistor. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a schematic structural diagram of a high-temperature resistant chip resistor provided by an embodiment of the present utility model;
[0024] Figure 2 This is a schematic diagram of the structure of the high temperature resistant chip resistor production process provided by the embodiment of the utility model Figure 1 ;
[0025] Figure 3 This is a schematic diagram of the structure of the high temperature resistant chip resistor production process provided by the embodiment of the utility model Figure 2 ;
[0026] Figure 4 This is a schematic diagram of the structure of the high temperature resistant chip resistor production process provided by the embodiment of the utility model Figure 3 ;
[0027] Figure 5 This is a schematic diagram of the structure of the high temperature resistant chip resistor production process provided by the embodiment of the utility model Figure 4 ;
[0028] Figure 6 This is a schematic diagram of the structure of the high temperature resistant chip resistor production process provided by the embodiment of the utility model Figure 5 ;
[0029] Figure 7 This is a schematic diagram of the structure of the high temperature resistant chip resistor production process provided by the embodiment of the utility model Figure 6 ;
[0030] Figure 8 This is a schematic diagram of the structure of the high temperature resistant chip resistor production process provided by the embodiment of the utility model Figure 7 ;
[0031] Figure 9 This is a schematic diagram of the structure of the high temperature resistant chip resistor production process provided by the embodiment of the utility model Figure 8 ;
[0032] Figure 10 This is a schematic diagram of the structure of the high temperature resistant chip resistor production process provided by the embodiment of the utility model Figure 9 .
[0033] In the picture:
[0034] 11. substrate;
[0035] 121. First front electrode; 122. Second front electrode;
[0036] 13. Resistor;
[0037] 141. First back electrode; 142. Second back electrode;
[0038] 151. First terminal electrode; 152. Second terminal electrode;
[0039] 16. Repair the resistance groove;
[0040] 17. Inner protective layer;
[0041] 18. Thermal insulation layer;
[0042] 19. Outer protective layer;
[0043] 20. Electroplated nickel layer;
[0044] 21. Electroplated tin layer;
[0045] 22. Marking layer. DETAILED DESCRIPTION
[0046] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.
[0047] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.
[0048] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.
[0049] In the description of this embodiment, terms such as "upper," "lower," and "right" are used to refer to positions or locations based on the positions or locations shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.
[0050] like Figure 1 As shown, this embodiment provides a high-temperature resistant chip resistor. The high-temperature resistant chip resistor in this embodiment is a thick film chip resistor. The high-temperature resistant chip resistor in this embodiment includes a substrate 11, a front electrode, a resistor body 13, a back electrode, and an end electrode. The front electrode includes a first front electrode 121 and a second front electrode 122. The first front electrode 121 and the second front electrode 122 are both arranged on the upper surface of the substrate 11 and are respectively located at the two ends of the substrate 11 along the first direction. The first direction is the length direction of the substrate 11. A resistor body 13 is provided on the upper surface of the substrate 11. The resistor body 13 connects the first front electrode 121 and the second front electrode 122. The resistor body 13 is arranged in the middle of the substrate 11 along the first direction, and the distance between the two ends of the resistor body 13 along the first direction is greater than 1 / 3 of the length of the substrate 11. The back electrode includes a first back electrode 141 and a second back electrode 142. The first back electrode 141 and the second back electrode 142 are both disposed on the lower surface of the substrate 11 and are respectively located at the two ends of the substrate 11 along the first direction. The distance between the two ends of the first back electrode 141 along the first direction is not less than 1 / 3 of the length of the substrate 11, and the distance between the two ends of the second back electrode 142 along the first direction is not less than 1 / 3 of the length of the substrate 11. The end electrodes include a first end electrode 151 and a second end electrode 152. The first end electrode 151 is disposed at one end of the substrate 11 along the first direction, and the second end electrode 152 is disposed at the other end of the substrate 11 along the first direction. The first end electrode 151 connects the first front electrode 121 and the first back electrode 141, and the second end electrode 152 connects the second front electrode 122 and the second back electrode 142.
[0051] In the high-temperature resistant chip resistor provided by this embodiment, the length of the first back electrode 141 and the second back electrode 142 along the first direction is not less than 1 / 3 of the length of the substrate 11, and the resistor body 13 is arranged in the middle of the substrate 11 along the first direction, and the length of the resistor body 13 along the first direction is greater than 1 / 3 of the length of the substrate 11, so that the ends of the first back electrode 141 and the second back electrode 142 close to each other can extend to directly below the resistor body 13, thereby accelerating the heat generated by the resistor body 13 to be transferred to the first back electrode 141 and the second back electrode 142 through the substrate 11 as soon as possible, and dissipating downward through the first back electrode 141 and the second back electrode 142 to the soldering pad of the high-temperature resistant chip resistor, so as to improve the heat dissipation capacity of the high-temperature resistant chip resistor, thereby improving the high temperature resistance and high power performance of the high-temperature resistant chip resistor.
[0052] Preferably, if Figure 4 As shown, the resistor 13 covers a portion of the first front electrode 121 and a portion of the second front electrode 122 .
[0053] Alternatively, as Figure 1 、 Figure 6 and Figure 7 As shown, the resistor body 13 is provided with a resistance trimming groove 16. The first end of the resistance trimming groove 16 along the second direction extends to the end surface of the first end of the resistor body 13 along the second direction. The length of the resistance trimming groove 16 along the second direction is no more than 1 / 4 of the length of the resistor body 13 along the second direction. The second direction is the width of the substrate 11. In other words, the distance between the second end of the resistance trimming groove 16 along the second direction and the second end of the resistor body 13 along the second direction is no less than 3 / 4 of the length of the resistor body 13 along the second direction. This embodiment increases the remaining size of the resistor body 13 along the second direction after resistance trimming to no less than 3 / 4 of the length of the resistor body 13 along the second direction, thereby avoiding the problem of insufficient power resistance in high-temperature resistant chip resistors.
[0054] Alternatively, as Figure 1 、 Figure 5 and Figure 6 As shown, the high-temperature resistant chip resistor provided in this embodiment further includes an inner protective layer 17, which covers at least a portion of the resistor body 13. Preferably, the inner protective layer 17 is made of a material that is bismuth (Bi)-free and contains lead (Pb). The inner protective layer 17 (primary protective layer) of existing chip resistors generally uses a Bi-containing system material. The high-temperature resistance of this series of materials fails to meet the performance requirements under high-temperature conditions, and Bi crystallization may occur under high-temperature applications. The present invention uses a Pb-containing system material with superior high-temperature resistance to improve the high-temperature resistance of the inner protective layer 17 (primary protective layer).
[0055] Alternatively, as Figure 1 、 Figure 8 and Figure 9 As shown, the high-temperature resistant chip resistor provided in this embodiment further includes a thermal insulation layer 18 and an outer protective layer 19. The thermal insulation layer 18 covers the inner protective layer 17 and the area where the resistor body 13 is exposed outside the inner protective layer 17. The outer protective layer 19 covers the thermal insulation layer 18. The outer protective layer 19 (secondary protective layer) of the existing chip resistor generally uses a 200°C epoxy resin paste material. In this embodiment, a thermal insulation layer 18 formed of a glass material with high temperature resistance and excellent heat dissipation capability is added between the inner protective layer 17 (primary protective layer) and the outer protective layer 19 (secondary protective layer) to accelerate and disperse the heat dissipation of the resistor body 13 and improve the high-temperature resistance of the protective layer.
[0056] Alternatively, as Figure 1 As shown, the high temperature resistant chip resistor provided in this embodiment further includes an electroplated nickel layer 20 , and the terminal electrodes, the back electrodes, and the areas of the front electrodes exposed from the outer protective layer 19 are all covered with the electroplated nickel layer 20 .
[0057] Alternatively, as Figure 1 As shown, the high temperature resistant chip resistor provided in this embodiment further includes an electroplated tin layer 21 , and the outer surface of the electroplated nickel layer 20 is covered with the electroplated tin layer 21 .
[0058] Preferably, the front electrode uses a silver-palladium electrode paste material containing not less than 10% palladium. The front electrodes of existing chip resistors generally use silver-palladium electrode paste materials containing less than 1% palladium (Pd) or pure silver electrode paste materials without palladium (Pd). The front electrode of this embodiment uses a silver-palladium electrode paste material containing ≥10% palladium (Pd), which solves the problem of excessive temperature drift of the electrode and resistor overlap when used in high-temperature environments. At the same time, the use of high-palladium-content surface electrode materials directly solves the problem of sulfurization of the silver electrode at the weak point between the front electrode and the outer protective layer 19 (secondary protective layer) in a sulfur-containing environment.
[0059] Alternatively, as Figure 1 and Figure 10 As shown, the high temperature resistant chip resistor provided by this embodiment further includes a marking layer 22 , which is disposed on the upper surface of the outer protective layer 19 .
[0060] The detailed preparation method of the high temperature resistant chip resistor provided in this embodiment is as follows:
[0061] This embodiment uses a rectangular insulating ceramic substrate. Specifically, zirconium oxide (ZrO2) insulating ceramic, which has a thermal conductivity superior to that of an aluminum oxide (Al2O3) ceramic substrate, is used as the substrate 11. Its thermal conductivity is approximately 16 W / (mK) under 300°C test conditions. Ordinary thick film chip resistors generally use aluminum oxide (Al2O3) with a thermal conductivity of approximately 12 W / (mK).
[0062] like Figure 2 As shown, on the back side of the rectangular insulating substrate 11, silver conductive paste is printed by thick film screen printing to obtain a first back electrode 141 and a second back electrode 142. The first back electrode 141 and the second back electrode 142 are both designed to be square or rectangular. The design size requirement B≥1 / 3L is to enable the first back electrode 141 and the second back electrode 142 to extend to directly below the resistor 13 on the substrate 11. B is the length of the first back electrode 141 and the second back electrode 142 along the first direction, and L is the length of the substrate 11 along the first direction.
[0063] like Figure 3 As shown, on the front side of the substrate 11, silver-palladium conductor paste is printed by thick film screen printing, and the front electrode material uses a silver-palladium electrode paste material containing palladium (Pd) ≥ 10% to obtain a first front electrode 121 and a second front electrode 122, and the first front electrode 121 and the second front electrode 122 are not connected. The first front electrode 121 and the second front electrode 122 are designed to be square or convex. In this embodiment, the first front electrode 121 and the second front electrode 122 are both square, and the front electrode and the back electrode are fired together at 840°C to 860°C.
[0064] like Figure 4 As shown, on the front side of the substrate 11, the resistor paste is printed by thick film screen printing and fired at 840°C to 860°C to obtain the resistor body 13, and the resistor body 13 is placed on the first front electrode 121 and the second front electrode 122 and connected thereto. The resistor body 13 is designed to be square.
[0065] like Figure 5 As shown, glass paste is printed on the front side of the substrate 11 by thick film screen printing. The material uses a primary protective material containing lead (Pb) with excellent high temperature resistance. It is fired at 600℃~620℃ to obtain the inner protective layer 17, which is required to completely cover the overlap between the above-mentioned resistor 13 and the front electrode or the resistance repair position.
[0066] like Figure 6 and Figure 7 As shown, laser drilling is performed in the vertical projection direction of the stacked structure. The cutting pattern can be a double-blade or L-shaped pattern in the same direction. This pattern removes or separates a portion of the resistor element 13 in the stacked structure, forming a resistance trimming groove 16. This changes the cross-sectional area of the resistor element 13 and achieves resistance adjustment. Furthermore, the remaining dimension W1 of the resistor element 13 after trimming is required to be ≥ 3 / 4W, where W1 is the distance between the second end of the resistance trimming groove 16 along the second direction and the second end of the resistor element 13 along the second direction, and W is the length of the resistor element 13 along the second direction. In this embodiment, the resistor groove is L-shaped.
[0067] like Figure 8As shown, a layer of thermal insulation material is printed on the stacked structure after the resistor is repaired by thick film screen printing. The material uses high-temperature resistant glass paste, and lead (Pb) or Bi glass material can be used. It is fired at 600℃~620℃ to obtain a high-temperature resistant thermal insulation layer 18 between the resistor body 13 and the outer protective layer 19. The design size of the thermal insulation layer 18 needs to completely cover the above-mentioned resistor body 13 (the effective size position is sufficient).
[0068] like Figure 9 As shown, epoxy resin slurry is printed on the front of the stacked structure using thick film screen printing and cured at 200°C to 210°C to form an outer protective layer 19. The outer protective layer 19 is designed to completely cover the resistor 13 (including the overlap between the resistor 13 and the front electrode) and the thermal insulation layer 18.
[0069] like Figure 10 As shown, on the front side of the insulating substrate 11, on the laminated structure, epoxy resin paste is printed by thick film screen printing and fired into a marking layer 22. The marking layer 22 can be processed or not.
[0070] like Figure 1 As shown, on both sides of the resistor, a first end electrode 151 and a second end electrode 152 are formed by vacuum sputtering metals such as nickel and chromium or coating conductive pastes such as silver paste, so as to connect the front electrode with the back electrode, and electroplating nickel layer 20 and electroplating tin layer 21 are respectively implemented on the exposed conductor structures of the front electrode, back electrode and end electrode.
[0071] The high temperature resistant chip resistor provided by this embodiment has the following advantages:
[0072] The application environment is increased from 70℃ for ordinary thick film chip resistors to 125℃, and the high-temperature power-on characteristics are improved from the upper limit of 125℃ for ordinary thick film chip resistors to 180℃; the sulfurization resistance and surge resistance characteristics are greatly improved compared with ordinary thick film chip resistors; and the rated power is doubled compared with ordinary thick film chip resistors.
[0073] Compared with ordinary thick film chip resistors, the high temperature resistant chip resistor provided in this embodiment significantly improves the product's high temperature resistance, surge resistance, sulfurization resistance, rated power, and application ambient temperature performance. The specific improved rated values are as follows:
[0074]
[0075]
[0076] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and replacements can be made without departing from the technical principles of the present invention. These improvements and replacements should also be regarded as the scope of protection of the present invention.
Claims
1. A high temperature resistant chip resistor, characterized in that: include: a substrate (11); A front electrode, comprising a first front electrode (121) and a second front electrode (122), wherein the first front electrode (121) and the second front electrode (122) are both arranged on the upper surface of the substrate (11) and are respectively located at two ends of the substrate (11) along a first direction, wherein the first direction is the length direction of the substrate (11); A resistor (13), the resistor (13) being provided on the upper surface of the substrate (11), the resistor (13) being connected to the first front electrode (121) and the second front electrode (122), the resistor (13) being provided in the middle of the substrate (11) along the first direction, and the length of the resistor (13) along the first direction being greater than 1 / 3 of the length of the substrate (11); A back electrode, comprising a first back electrode (141) and a second back electrode (142), wherein the first back electrode (141) and the second back electrode (142) are both arranged on the lower surface of the substrate (11) and are respectively located at two ends of the substrate (11) along the first direction, the length of the first back electrode (141) along the first direction is not less than 1 / 3 of the length of the substrate (11), and the length of the second back electrode (142) along the first direction is not less than 1 / 3 of the length of the substrate (11); An end electrode comprises a first end electrode (151) and a second end electrode (152), wherein the first end electrode (151) is provided at one end of the substrate (11) along the first direction, and the second end electrode (152) is provided at the other end of the substrate (11) along the first direction, wherein the first end electrode (151) connects the first front electrode (121) and the first back electrode (141), and the second end electrode (152) connects the second front electrode (122) and the second back electrode (142).
2. The high temperature resistant chip resistor according to claim 1, characterized in that: The resistor (13) is provided with a resistance repair groove (16), wherein the first end of the resistance repair groove (16) along the second direction extends to the end surface of the first end of the resistor (13) along the second direction, and the length of the resistance repair groove (16) along the second direction is not greater than 1 / 4 of the length of the resistor (13) along the second direction, and the second direction is the width direction of the substrate (11).
3. The high temperature resistant chip resistor according to claim 1 or 2, characterized in that: The resistor (13) covers a portion of the first front electrode (121) and a portion of the second front electrode (122).
4. The high temperature resistant chip resistor according to claim 3, characterized in that: It also includes an inner protective layer (17), and the inner protective layer (17) covers at least a partial area of the resistor (13).
5. The high temperature resistant chip resistor according to claim 4, characterized in that: It also includes a heat insulation layer (18), wherein the heat insulation layer (18) covers the inner protective layer (17) and the area where the resistor (13) is exposed outside the inner protective layer (17).
6. The high temperature resistant chip resistor according to claim 5, characterized in that: The utility model further comprises an outer protective layer (19), wherein the outer protective layer (19) covers the heat insulating layer (18).
7. The high temperature resistant chip resistor according to claim 6, characterized in that: It also includes an electroplated nickel layer (20), and the end electrode, the back electrode, and the area of the front electrode exposed from the outer protective layer (19) are all covered with the electroplated nickel layer (20).
8. The high temperature resistant chip resistor according to claim 7, characterized in that: It also includes an electroplated tin layer (21), and the outer surface of the electroplated nickel layer (20) is covered with the electroplated tin layer (21).
9. The high temperature resistant chip resistor according to claim 4, characterized in that: The inner protective layer (17) is made of a bismuth-free and lead-containing material.
10. The high temperature resistant chip resistor according to claim 1 or 2, characterized in that: The front electrode is made of silver-palladium electrode paste material containing no less than 10% palladium.