Thick-film resistor

Abstract

The utility model relates to the technical field of electronic components, in particular to a thick-film resistor. The thick-film resistor comprises a substrate, a first electrode is printed on the bottom surface of the substrate, second electrodes are printed on the two opposite sides of the top surface of the substrate respectively, at least two resistors arranged at intervals are printed between the two second electrodes, and the multiple resistors are connected to the two second electrodes in parallel. According to the thick-film resistor, the problem of quick local heating caused by slow heat dissipation of a conventional structure can be prevented, so that the use risk of the thick-film resistor is reduced, the withstand current is improved, and the application of the thick-film resistor is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic components, in particular to a thick film resistor. Background Art

[0002] Thick-film resistors are typically created by printing a square pattern onto a substrate, followed by high-temperature sintering. This process is mature and has long been mass-produced. With the miniaturization and miniaturization of application equipment, the size of thick-film resistors is becoming increasingly smaller, with some even reaching the 0402 size. The electrical system voltage of new energy vehicles has increased from 450V to 800V, and the IGBT module voltage in inverters and converters has also increased, placing increasingly stringent current requirements on thick-film resistors.

[0003] Currently, thick film resistors have low current resistance. At the same time, there is a problem of rapid local heating caused by slow heat dissipation, which increases the risk of use and hinders the application of thick film resistors. Utility Model Content

[0004] The technical problem to be solved by the embodiments of the present invention is to provide a thick film resistor to solve the problem that the current thick film resistors in the prior art have low current resistance and, at the same time, there is a problem of rapid local heating caused by slow heat dissipation, which increases the risk of use and hinders the application of thick film resistors.

[0005] The utility model discloses a thick film resistor, comprising: a substrate, a first electrode printed on the bottom surface of the substrate, second electrodes printed on two opposite sides of the top surface of the substrate, at least two resistors spaced apart are printed between the two second electrodes, and a plurality of the resistors are connected in parallel to the two second electrodes.

[0006] Optionally, the cross-sections of the plurality of resistors are rectangular.

[0007] Optionally, a first protective layer is printed between the two second electrodes, and the first protective layer covers the resistor.

[0008] Optionally, a second protective layer is printed between the two second electrodes, and the second protective layer covers the resistor.

[0009] Optionally, the substrate is made of alumina ceramic material.

[0010] Optionally, both the first electrode and the second electrode are made of metal material.

[0011] Optionally, a first notch and a second notch are respectively formed on two opposite sides of the resistor along its length direction, and the first notch and the second notch are staggered on the resistor.

[0012] Compared with the prior art, the beneficial effect of the thick film resistor provided by the embodiment of the present invention is that: a first electrode is printed on the bottom surface of the substrate, and second electrodes are printed on opposite sides of the top surface of the substrate. At least two resistors are printed between the two second electrodes, and multiple resistors are connected in parallel on the two second electrodes. The above configuration changes the structure of the printed resistors of the thick film resistor. The above resistor spacing printing structure facilitates the heat dissipation of the resistors during use. At the same time, at the same resistance value, the withstand current of the thick film resistor of the present invention is increased by 20% compared with the conventional structure. Therefore, the thick film resistor of this embodiment can prevent the problem of localized rapid heating caused by slow heat dissipation of the conventional structure, thereby reducing the risk of using the thick film resistor, while increasing the withstand current, thereby improving the application of the thick film resistor. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, in which:

[0014] Figure 1 This is one of the structural diagrams of the thick film resistor provided by the embodiment of the present utility model;

[0015] Figure 2 This is an exploded view of a thick film resistor provided by an embodiment of the present utility model;

[0016] Figure 3 This is a bottom view of a thick film resistor provided by an embodiment of the present utility model;

[0017] Figure 4 This is a schematic diagram of the printed structure of a resistor provided by one embodiment of the present utility model;

[0018] Figure 5 This is a schematic diagram of a printed structure of a resistor provided by another embodiment of the present invention;

[0019] Figure 6 This is a schematic diagram of the printed structure of a resistor provided by another embodiment of the present invention;

[0020] Figure 7 This is a schematic diagram of the current resistance of the thick film resistor provided by the embodiment of the utility model and the conventional structure;

[0021] Figure 8 This is a flow chart of a method for preparing a thick film resistor provided by an embodiment of the present utility model.

[0022] The reference numerals in the figures are:

[0023] 10. Substrate; 20. First electrode; 30. Second electrode; 40. Resistor; 401. First notch; 402. Second notch; 510. First protective layer; 520. Second protective layer. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. Now, in conjunction with the accompanying drawings, a detailed description of the preferred embodiments of the present utility model will be given.

[0025] The present invention provides a thick film resistor. Figure 1 As shown, the thick film resistor includes: a substrate 10, a first electrode 20 is printed on the bottom surface of the substrate 10, second electrodes 30 are printed on opposite sides of the top surface of the substrate 10, and at least two resistors 40 are printed between the two second electrodes 30, and multiple resistors 40 are connected in parallel on the two second electrodes 30.

[0026] A first electrode 20 is printed on the bottom surface of the substrate 10, and second electrodes 30 are printed on opposite sides of the top surface of the substrate 10. At least two resistors 40 are printed between the two second electrodes 30, and multiple resistors 40 are connected in parallel on the two second electrodes 30. The above arrangement changes the structure of the printed resistors 40 of the thick film resistor. The printed structure of the resistors 40 facilitates heat dissipation of the resistors 40 during use. At the same time, under the same resistance value, the withstand current of the thick film resistor of the present invention is increased by 20% compared with the conventional structure. Therefore, the thick film resistor of this embodiment can prevent the problem of local rapid heating caused by slow heat dissipation of the conventional structure, thereby reducing the risk of using the thick film resistor, while increasing the withstand current, thereby improving the application of the thick film resistor.

[0027] The calculation of the resistance values of the plurality of resistors 40 connected in parallel is carried out using existing technology and is not specifically limited here.

[0028] As a preferred solution of this embodiment, refer to Figure 4 and Figure 5 , the cross-section of the plurality of resistors 40 is a rectangular structure.

[0029] In actual applications, the resistance of resistor 40 is related to the size and thickness of its cross section. Printing the cross section of resistor 40 in a rectangular structure allows for precise control of the size and thickness of the rectangle, thereby achieving higher resistance accuracy and stability. Furthermore, the rectangular structure facilitates better heat dissipation, reducing heat accumulation, further reducing the risks of using thick film resistors. Furthermore, the rectangular structure is relatively simple, and the printing manufacturing process is relatively easy to control, improving production efficiency.

[0030] Reference Figure 4 and Figure 5 , respectively, give examples of three and four resistors 40 connected in parallel. In actual application, the resistance value can be adjusted according to the actual application, and no specific limitation is made here.

[0031] In actual application, the resistance of resistor 40 Wherein, ρ represents the resistivity, which is related to the material composition of the resistor 40, and the unit is Ω·m; L represents the printed length of the resistor 40, and the unit is m; S represents the cross-sectional area of the resistor 40, and the unit is m 2 .

[0032] As a preferred solution of this embodiment, refer to Figure 2 A first protective layer 510 is printed between the two second electrodes 30 , and the first protective layer 510 covers the resistor 40 .

[0033] In the actual production process of thick film resistors, the resistor 40 is generally trimmed by laser after printing so that its resistance value reaches a preset value. During the laser trimming process, the setting of the first protective layer 510 can absorb the heat of the laser. During the laser resistance adjustment process, it can prevent the heat of the laser from damaging the resistor 40, thereby protecting the resistor 40. The above-mentioned first protective layer 510 can be made of glass paste.

[0034] As a preferred solution of this embodiment, refer to Figure 2 A second protective layer 520 is printed between the two second electrodes 30 , and the second protective layer 520 covers the resistor 40 .

[0035] During the actual production of thick-film resistors, after laser resistance trimming, the second protective layer 520 is used to seal the resistor 40, protecting it from external environmental influences such as moisture and dust, thereby enhancing the stability and long-term reliability of the thick-film resistor. Furthermore, the second protective layer 520 provides a certain degree of mechanical protection, preventing the resistor 40 from accidental impacts or scratches, thereby extending the service life of the thick-film resistor. Furthermore, the second protective layer 520 also improves the insulation performance of the thick-film resistor, reducing electrical contact between the resistor 40 and other components or conductors, lowering the risk of leakage current, and further reducing the risk of using the film resistor 40. The second protective layer 520 can be made of glass paste.

[0036] As a preferred solution of this embodiment, the substrate 10 is made of alumina ceramic material.

[0037] Among them, alumina ceramic material has good thermal conductivity and thermal stability, which can effectively dissipate heat and reduce the temperature of thick-film resistors, further reducing the risk of using thick-film resistors and improving the stability and reliability of thick-film resistors. At the same time, alumina ceramic is an excellent insulating material that can effectively prevent current leakage and improve the safety and reliability of thick-film resistors.

[0038] As a preferred solution of this embodiment, the first electrode 20 and the second electrode 30 are both made of metal materials.

[0039] For example, the first electrode 20 and the second electrode 30 of this embodiment are made of silver. Silver is an excellent conductive metal with very low resistivity, which can provide efficient current transmission and reduce the power loss of thick-film resistors. Silver also has good thermal conductivity, which helps to quickly dissipate heat during operation of the thick-film resistor, reducing temperature rise and improving the stability and reliability of the thick-film resistor.

[0040] As a preferred solution of this embodiment, refer to Figure 6 The resistor 40 is formed with a first notch 401 and a second notch 402 on opposite sides along its length direction, respectively. The first notch 401 and the second notch 402 are staggered on the resistor 40 .

[0041] The arrangement of the first notch 401 and the second notch 402 allows the resistor 40 to form an S-shaped current channel, thereby increasing the effective path of the current and further improving the stability and reliability of the thick film resistor.

[0042] The manufacturing method of the thick film resistor according to the embodiment of the present application comprises the following steps:

[0043] S10: Taking a substrate 10, printing a first electrode 20 on the bottom surface of the substrate 10, and printing a second electrode 30 on opposite sides of the substrate 10 respectively. After the first electrode 20 and the second electrode 30 are dried, the substrate 10 is sintered and solidified;

[0044] S20: Printing a plurality of resistors 40 spaced apart on the substrate 10, and after the resistors 40 are dried, sintering and curing the substrate 10;

[0045] S30: Printing a first protective layer 510 on the resistor 40. After the first protective layer 510 is dried, sintering and curing the substrate 10, and performing laser trimming on the resistor 40 on the substrate 10 to achieve a preset resistance value of the thick film resistor;

[0046] S40 : printing the second protective layer 520 on the first protective layer 510 , and after the second protective layer 520 is dried, sintering and curing the substrate 10 .

[0047] The thick film resistor of the above embodiment can be obtained according to the above manufacturing method. The sintering method has a simple preparation process and is convenient for the production of thick film resistors.

[0048] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Those skilled in the art may modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein; and all these modifications and replacements should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A thick film resistor, characterized in that: include: A substrate, wherein a first electrode is printed on the bottom surface of the substrate, second electrodes are printed on two opposite sides of the top surface of the substrate, and at least two resistors are printed between the two second electrodes, and multiple resistors are connected in parallel to the two second electrodes.

2. The thick film resistor according to claim 1, wherein The cross sections of the plurality of resistors are rectangular.

3. The thick film resistor according to claim 1, wherein A first protective layer is printed between the two second electrodes, and the first protective layer covers the resistor.

4. The thick film resistor according to claim 3, wherein: A second protective layer is printed between the two second electrodes, and the second protective layer covers the resistor.

5. The thick film resistor according to claim 1, wherein The substrate is made of alumina ceramic material.

6. The thick film resistor according to claim 1, wherein: The first electrode and the second electrode are both made of metal material.

7. The thick film resistor according to claim 1, wherein: The resistor is respectively formed with a first notch and a second notch on two opposite sides along the length direction thereof, and the first notch and the second notch are staggered on the resistor.

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