Resistor paste and chip resistor

Abstract

The present invention discloses a resistor paste and a chip resistor. A resistor paste, comprising a conductive phase, copper oxide and MnO2, wherein the conductive phase is at least one of ruthenium compounds, and the mass ratio of copper oxide and MnO2 satisfies 0.2≤copper oxide / MnO2≤4.3. The resistor paste of the present invention dopes the conductive phase with copper oxide and MnO2, wherein the doping of copper oxide can increase the resistance of the prepared chip resistor after electrostatic impact, and the doping of MnO2 can reduce the resistance of the prepared chip resistor after electrostatic impact. When the mass ratio of copper oxide / MnO2 is 0.2-4.3, the doping of the two plays a suitable synergistic role, so that the prepared chip resistor has excellent electrostatic performance, and the absolute value of the resistance change rate after 3 positive and negative impacts of 5KV electrostatic is no more than 5%.

Description

Technical Field

[0001] The invention belongs to the field of electronic paste, and in particular relates to a resistor paste and a chip resistor. Background Art

[0002] As important electronic components, chip resistors are widely used in thick film circuits, hybrid integrated circuits, electronic equipment and other fields. During use in some specific scenarios, chip resistors will be subjected to high-voltage electrostatic shocks, causing their resistance to change. The higher the voltage of the electrostatic shock, the greater the change in resistance. When the resistance change rate exceeds a certain range, the chip resistor will fail. Electrostatic performance is usually used to characterize the electrostatic shock resistance of chip resistors. The better the electrostatic performance, the smaller the resistance change rate after high-voltage electrostatic shock.

[0003] The electrostatic performance of a chip resistor mainly depends on the resistor layer therein, which is formed by printing a resistor paste on an insulating substrate and sintering it. The higher the conductive phase content in the resistor paste, the better the electrostatic performance of the prepared chip resistor. However, the increase in the conductive phase content limits the application of the resistor paste in a wide resistance range (especially in high resistance segments) on the one hand, and greatly increases the cost on the other hand. Therefore, it is necessary to find a suitable resistor paste formulation system to improve the electrostatic performance of the prepared chip resistor while taking into account a wide resistance application range and low cost, so that it can be suitable for applications with high requirements for electrostatic shock resistance. Summary of the invention

[0004] In order to overcome the problem of poor electrostatic impact resistance of existing chip resistors, one of the objects of the present invention is to provide a resistor paste, the second object of the present invention is to provide a method for preparing the resistor paste, and the third object of the present invention is to provide a chip resistor.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The first aspect of the present invention provides a resistor paste, the components of the resistor paste include a conductive phase, copper oxide and MnO 2 , the conductive phase is at least one of a ruthenium compound, copper oxide and MnO 2 The mass ratio of copper oxide / MnO satisfies 0.2≤ 2 ≤4.3; copper oxides are CuO and Cu 2 At least one of O.

[0007] Copper oxide and MnO in resistor paste 2 It can be used for ruthenium-based conductive materials (such as RuO 2 ) is doped. The doping of copper oxide can increase the resistance of the prepared chip resistor after electrostatic shock, while MnO2 The doping of copper oxide / MnO can reduce the resistance of the prepared chip resistor after electrostatic shock. 2 When the mass ratio of copper oxide / MnO is between 0.2 and 4.3, the two doping plays a suitable synergistic role, so that the prepared chip resistor has excellent electrostatic properties; when the copper oxide / MnO 2 When the mass ratio of copper oxide / MnO is less than 0.2, the resistance of the prepared chip resistor decreases too much after electrostatic shock, and the electrostatic performance is poor; 2 When the mass ratio is greater than 4.3, the resistance of the prepared chip resistor increases too much after electrostatic shock, and the electrostatic performance is poor.

[0008] Among them, copper oxide / MnO 2 The mass ratio of can be obtained by X-ray fluorescence spectrometer (XRF) method.

[0009] Preferably, the resistor paste, copper oxide and MnO 2 The mass ratio of copper oxide / MnO satisfies 0.3≤ 2 ≤3.2; Further preferably, copper oxide and MnO 2 The mass ratio of copper oxide / MnO satisfies 0.4≤ 2 ≤2; Further preferably, copper oxide and MnO 2 The mass ratio of copper oxide / MnO satisfies 0.45≤ 2 ≤1.2; Further preferably, copper oxide and MnO 2 The mass ratio of copper oxide / MnO satisfies 0.5≤ 2 ≤0.7.

[0010] Preferably, the resistor paste is composed of 40-80wt% inorganic components and 20-60wt% organic components; the inorganic components include the following components in mass percentage: 3-35wt% conductive phase, 60-96wt% glass and 0.05-10wt% inorganic additives; the organic components include the following components in mass percentage: 5-15wt% resin, 75-94wt% organic solvent and 0.1-10wt% organic additives.

[0011] Preferably, in the resistor paste, the conductive phase is at least one of ruthenium dioxide, lead ruthenate and bismuth ruthenate.

[0012] Preferably, in the resistor paste, the grain size of the conductive phase is 5-100 nm.

[0013] Preferably, in this resistor paste, the average grain size of the conductive phase is 10-80nm; further preferably, the average grain size of the conductive phase is 20-50nm; further preferably, the average grain size of the conductive phase is 22-30nm; further preferably, the average grain size of the conductive phase is 25nm.

[0014] Preferably, the resistor paste glass comprises the following components in mass percentage: 22-65wt% SiO 2 、10-50wt% PbO、2-18wt% B 2 O 3 、1-15wt%BaO、1-15wt%Al 2 O 3 ,1-12wt%ZnO,0.1-6wt%MnO 2 , 0.1-6wt% copper oxide, 0-5wt% CaO, 0-5wt% MgO, 0-6wt% SrO, 0-5wt% Na 2 O, 0-5wt%K 2 O.

[0015] Preferably, in the resistor paste, the glass particle size is 0.5-2 μm.

[0016] Preferably, in the resistor paste, the average particle size of the glass is 1.3-1.7 μm; more preferably, the average particle size of the glass is 1.4-1.6 μm; and even more preferably, the average particle size of the glass is 1.5 μm.

[0017] Preferably, the inorganic additives of the resistor paste include copper oxide, MnO 2 , Nb 2 O 5 、 2 O 5 、ZrO 2 、TiO 2 At least one of; copper oxides are CuO and Cu 2 At least one of O.

[0018] Preferably, in the resistor paste, the particle size of the inorganic additive is 0.5-2 μm.

[0019] Preferably, in the resistor paste, the average particle size of the inorganic additive is 1.8-2.2 μm; more preferably, the average particle size of the inorganic additive is 1.9-2.1 μm; and even more preferably, the average particle size of the inorganic additive is 2 μm.

[0020] Preferably, the resistor paste comprises at least one of methyl cellulose, ethyl cellulose, acrylic resin, epoxy resin, alkyd resin, terpene resin and modified rosin resin.

[0021] Preferably, the organic solvent of the resistor paste includes at least one of terpineol, butyl carbitol, butyl carbitol acetate, diethylene glycol dibutyl ether, turpentine, isobornyl acetate, dibutyl phthalate, and alcohol ester dodecahydrate.

[0022] Preferably, the organic additive of the resistor paste includes at least one of sodium lauryl sulfate, methyl amyl alcohol, aminopropylamine dioleate, oleyl amino oleate, and lecithin.

[0023] The second aspect of the present invention provides a method for preparing the above-mentioned resistor paste, comprising the following steps:

[0024] (1) mixing and dissolving a resin, an organic solvent, and an organic additive to obtain an organic carrier; mixing a conductive phase, glass, and an inorganic additive to obtain an inorganic mixed powder;

[0025] (2) The inorganic mixed powder and the organic carrier are mixed, stirred, and then slurried to obtain a resistor paste.

[0026] Preferably, in the method for preparing the resistor paste, in step (1), the temperature for mixing and dissolving the resin, the organic solvent and the organic additive is 60-120°C.

[0027] Preferably, in the method for preparing the resistor paste, in step (1), the mixed dissolution process of the resin, organic solvent and organic additive is carried out by stirring; further preferably, straight blade paddle stirring is adopted; further preferably, the stirring speed is 10-480rpm / min; in some preferred embodiments of the present invention, the stirring speed is 280rpm / min.

[0028] Preferably, in the method for preparing the resistor slurry, in step (2), the stirring is performed by straight-blade paddle stirring; further preferably, the stirring speed is 60-720 rpm / min; further preferably, the stirring speed is 400-720 rpm / min; in some preferred embodiments of the present invention, the stirring speed is 580 rpm / min.

[0029] Preferably, in the method for preparing the resistor paste, in step (2), the inorganic mixed powder is mixed with the organic carrier, stirred, and then the mixed materials are dispersed again by a three-roll mill to obtain the resistor paste.

[0030] A third aspect of the present invention provides a chip resistor, comprising: a substrate and a resistor layer, wherein the resistor layer is arranged on the surface of the substrate, and the resistor layer is prepared from the above-mentioned resistor paste.

[0031] Preferably, the absolute value of the resistance change rate of the chip resistor after 3 positive and negative 5KV static shocks does not exceed 5%.

[0032] Preferably, for this chip resistor, the average thickness of the resistor layer on the chip resistor is 8-16μm; further preferably, the average thickness of the resistor layer on the chip resistor is 10-14μm; still further preferably, the average thickness of the resistor layer on the chip resistor is 11-13μm; further preferably, the average thickness of the resistor layer on the chip resistor is 12μm.

[0033] The present invention also provides a method for preparing the above-mentioned chip resistor, which specifically comprises the following steps: printing resistor paste on a substrate by a screen printing process, and obtaining the chip resistor after sintering.

[0034] Preferably, in the method for preparing the chip resistor, the substrate is an aluminum oxide substrate.

[0035] Preferably, in the method for preparing the chip resistor, the sintering temperature is 750-950°C; more preferably, the sintering temperature is 800-900°C; even more preferably, the sintering temperature is 850°C.

[0036] The beneficial effects of the present invention are:

[0037] The resistor paste of the present invention comprises copper oxide and MnO 2 The conductive phase is doped with copper oxide, which can increase the resistance of the prepared chip resistor after electrostatic shock, while MnO 2 The doping of copper oxide / MnO can reduce the resistance of the prepared chip resistor after electrostatic shock. 2 When the mass ratio of is between 0.2 and 4.3, the doping of the two plays a suitable synergistic role, so that the prepared chip resistor has excellent electrostatic performance, and the absolute value of the resistance change rate after 3 positive and negative impacts of 5KV electrostatic charge does not exceed 5%. DETAILED DESCRIPTION

[0038] The content of the present invention is further described in detail below through specific examples. It should be understood that the specific embodiments described in this specification are only for explaining the present invention, not for limiting the present invention. The specific process parameters of the following examples are also only examples in a suitable range, that is, those skilled in the art can make selections within a suitable range through the description of this article, and are not limited to the specific data of the following examples. The raw materials used in the examples, if not otherwise specified, can be obtained from conventional commercial sources.

[0039] The grain size of the conductive phase used in the following examples and comparative examples is 5-100 nm, and the average grain size is 25 nm.

[0040] The glass used in the following examples and comparative examples has a particle size of 0.5-2 μm, and an average particle size of 1.5 μm.

[0041] The particle size of the inorganic additives used in the following examples and comparative examples is 0.2-5 μm, and the average particle size is 2 μm.

[0042] The component contents of different glass types used in the following examples and comparative examples are shown in Table 1 below.

[0043] Table 1 Glass component content

[0044]

[0045] Example 1

[0046] The raw materials and contents of the resistor paste of this embodiment are shown in Table 2 below.

[0047] Table 2 Preparation materials and contents of resistor paste in this example

[0048]

[0049] The method for preparing the resistor paste of this embodiment includes the following steps:

[0050] (1) Mixing and stirring the resin and the organic solvent at 80° C. (stirring method is straight-blade paddle type, stirring speed is 280 rpm) to dissolve, then adding the organic additive, filtering and cooling to obtain a viscous colloidal organic carrier;

[0051] (2) premixing and dispersing the conductive phase, glass, and inorganic additives to obtain an inorganic mixed powder;

[0052] (3) The organic carrier and the inorganic mixed powder are first stirred (stirring method is straight blade paddle type, stirring speed is 580 rpm) for premixing, and then fully dispersed by a three-roll mill to finally obtain a resistor slurry.

[0053] Example 2

[0054] The raw materials and contents of the resistor paste of this embodiment are shown in Table 3 below.

[0055] Table 3 Preparation materials and contents of resistor paste in this example

[0056]

[0057] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 3.

[0058] Example 3

[0059] The raw materials and contents of the resistor paste of this embodiment are shown in Table 4 below.

[0060] Table 4 Preparation materials and contents of resistor paste in this example

[0061]

[0062] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 4.

[0063] Example 4

[0064] The raw materials and contents of the resistor paste of this embodiment are shown in Table 5 below.

[0065] Table 5 Raw materials and contents of the resistor paste in this example

[0066]

[0067] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 5.

[0068] Example 5

[0069] The raw materials and contents of the resistor paste of this embodiment are shown in Table 6 below.

[0070] Table 6 Preparation materials and contents of resistor paste in this example

[0071]

[0072] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 6.

[0073] Example 6

[0074] The raw materials and contents of the resistor paste of this embodiment are shown in Table 7 below.

[0075] Table 7 Preparation materials and contents of resistor paste in this example

[0076]

[0077]

[0078] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 7.

[0079] Example 7

[0080] The raw materials and contents of the resistor paste of this embodiment are shown in Table 8 below.

[0081] Table 8 Preparation materials and contents of resistor paste in this example

[0082]

[0083] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 8.

[0084] Example 8

[0085] The raw materials and contents of the resistor paste of this embodiment are shown in Table 9 below.

[0086] Table 9 Preparation materials and contents of resistor paste in this example

[0087]

[0088] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 9.

[0089] Example 9

[0090] The raw materials and contents of the resistor paste of this embodiment are shown in Table 10 below.

[0091] Table 10 Preparation materials and contents of resistor paste in this example

[0092]

[0093] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 10.

[0094] Example 10

[0095] The raw materials and contents of the resistor paste of this embodiment are shown in Table 11 below.

[0096] Table 11 Raw materials and contents of the resistor paste in this example

[0097]

[0098] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition of Table 11.

[0099] Embodiment 11

[0100] The raw materials and contents of the resistor paste of this embodiment are shown in Table 12 below.

[0101] Table 12 Preparation materials and contents of resistor paste in this example

[0102]

[0103]

[0104] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 12.

[0105] Example 12

[0106] The raw materials and contents of the resistor paste of this embodiment are shown in Table 13 below.

[0107] Table 13 Preparation materials and contents of resistor paste in this example

[0108]

[0109] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 13.

[0110] Embodiment 13

[0111] The raw materials and contents of the resistor paste of this embodiment are shown in Table 14 below.

[0112] Table 14 Preparation materials and contents of resistor paste in this example

[0113]

[0114] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 14.

[0115] Embodiment 14

[0116] The raw materials and contents of the resistor paste of this embodiment are shown in Table 15 below.

[0117] Table 15 Preparation materials and contents of resistor paste in this example

[0118]

[0119]

[0120] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 15.

[0121] Embodiment 15

[0122] The raw materials and contents of the resistor paste of this embodiment are shown in Table 16 below.

[0123] Table 16 Raw materials and contents of the resistor paste in this example

[0124]

[0125] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 16.

[0126] Example 16

[0127] The raw materials and contents of the resistor paste of this embodiment are shown in Table 17 below.

[0128] Table 17 Preparation materials and contents of resistor paste in this example

[0129]

[0130] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 17.

[0131] Embodiment 17

[0132] The raw materials and contents of the resistor paste of this embodiment are shown in Table 18 below.

[0133] Table 18 Preparation materials and contents of resistor paste in this example

[0134]

[0135] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 18.

[0136] Embodiment 18

[0137] The raw materials and contents of the resistor paste of this embodiment are shown in Table 19 below.

[0138] Table 19 Raw materials and contents of the resistor paste in this example

[0139]

[0140] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 19.

[0141] Embodiment 19

[0142] The raw materials and contents of the resistor paste of this embodiment are shown in Table 20 below.

[0143] Table 20 Preparation materials and contents of resistor paste in this example

[0144]

[0145]

[0146] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 20.

[0147] Embodiment 20

[0148] The raw materials and contents of the resistor paste of this embodiment are shown in Table 21 below.

[0149] Table 21 Preparation materials and contents of resistor paste in this example

[0150]

[0151] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition of Table 21.

[0152] Embodiment 21

[0153] The raw materials and contents of the resistor paste of this embodiment are shown in Table 22 below.

[0154] Table 22 Preparation materials and contents of resistor paste in this example

[0155]

[0156]

[0157] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formula composition in Table 22.

[0158] Embodiment 22

[0159] The raw materials and contents of the resistor paste of this embodiment are shown in Table 23 below.

[0160] Table 23 Raw materials and contents of the resistor paste in this example

[0161]

[0162]

[0163] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formula composition in Table 23.

[0164] Embodiment 23

[0165] The raw materials and contents of the resistor paste of this embodiment are shown in Table 24 below.

[0166] Table 24 Raw materials and contents of the resistor paste in this example

[0167]

[0168] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formula composition in Table 24.

[0169] Embodiment 24

[0170] The raw materials and contents of the resistor paste of this embodiment are shown in Table 25 below.

[0171] Table 25 Preparation materials and contents of resistor paste in this example

[0172]

[0173] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formula composition in Table 25.

[0174] Embodiment 25

[0175] The raw materials and contents of the resistor paste of this embodiment are shown in Table 26 below.

[0176] Table 26 Raw materials and contents of the resistor paste in this example

[0177]

[0178] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formula composition in Table 26.

[0179] Embodiment 26

[0180] The raw materials and contents of the resistor paste of this embodiment are shown in Table 27 below.

[0181] Table 27 Preparation materials and contents of resistor paste in this example

[0182]

[0183] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formula composition in Table 27.

[0184] Comparative Example 1

[0185] The raw materials and contents of the resistor paste of this comparative example are shown in Table 28 below.

[0186] Table 28 Raw materials and contents of the resistor paste in this example

[0187]

[0188]

[0189] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formula composition in Table 28.

[0190] Comparative Example 2

[0191] The raw materials and contents of the resistor paste in this comparative example are shown in Table 29 below.

[0192] Table 29 Raw materials and contents of the resistor paste in this example

[0193]

[0194] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formula composition in Table 29.

[0195] Comparative Example 3

[0196] The raw materials and contents of the resistor paste in this comparative example are shown in Table 30 below.

[0197] Table 30 Preparation materials and contents of resistor paste in this example

[0198]

[0199]

[0200] Referring to the preparation method of Example 1, the resistor paste of this example was prepared according to the formulation composition in Table 30.

[0201] The resistor paste prepared in the above embodiments and comparative examples was printed on an alumina substrate by screen printing, and a chip resistor was obtained after sintering at 850° C. The size of the resistor layer on the chip resistor was: 1.75 mm in length, 1 mm in width, and an average thickness of 12 μm.

[0202] The chip resistors prepared from the resistor pastes prepared in the above embodiments and comparative examples were subjected to an electrostatic performance test. The test method was: 5KV static electricity was applied 3 times each, positive and negative, through an electrostatic discharge gun, and the resistance change rate before and after discharge was calculated. The test results are shown in Table 31 below.

[0203] Table 31 Electrostatic performance test results of embodiments and comparative examples

[0204]

[0205]

[0206] From the data of the above examples and comparative examples, it can be seen that the copper oxide and MnO 2 The mass ratio of copper oxide / MnO satisfies 0.2≤ 2 When the resistance is ≤4.3, the resistor paste has excellent electrostatic discharge resistance. The absolute value of the resistance change rate after 3 positive and negative 5KV electrostatic shocks does not exceed 5%.

[0207] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A resistor paste, characterized in that: The resistor paste comprises a conductive phase, copper oxide and MnO2, wherein the conductive phase is at least one of ruthenium compounds, and the mass ratio of the copper oxide to MnO2 satisfies 0.2≤copper oxide / MnO2≤4.3; The resistor paste is composed of 40-80wt% inorganic components and 20-60wt% organic components; the inorganic components include the following components by mass percentage: 3-35wt% conductive phase, 60-96wt% glass and 0.05-10wt% inorganic additives; the organic components include the following components by mass percentage: 5-15wt% resin, 75-94wt% organic solvent and 0.1-10wt% organic additives; The glass includes the following components in mass percentage: 22-65wt% SiO2, 10-50wt% PbO, 2-18wt% B2O3, 1-15wt% BaO, 1-15wt% Al2O3, 1-12wt% ZnO, 0.1-6wt% MnO2, 0.1-6wt% copper oxide, 0-5wt% CaO, 0-5wt% MgO, 0-6wt% SrO, 0-5wt% Na2O, and 0-5wt% K2O.

2. The resistor paste according to claim 1, characterized in that: The conductive phase is at least one of ruthenium dioxide, lead ruthenate and bismuth ruthenate.

3. The resistor paste according to claim 1, characterized in that: The grain size of the conductive phase is 5-100 nm.

4. The resistor paste according to claim 1, characterized in that: The inorganic additive includes at least one of copper oxide, MnO2, Nb2O5, Ta2O5, ZrO2, and TiO2.

5. The resistor paste according to claim 1, characterized in that: The resin includes at least one of methyl cellulose, ethyl cellulose, acrylic resin, epoxy resin, alkyd resin, terpene resin and modified rosin resin.

6. The resistor paste according to claim 2, characterized in that: The organic solvent includes at least one of terpineol, butyl carbitol, butyl carbitol acetate, diethylene glycol dibutyl ether, turpentine, isobornyl acetate, dibutyl phthalate, and alcohol ester dodecaned.

7. The method for preparing the resistor paste according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) Mixing and dissolving a resin, an organic solvent, and an organic additive to obtain an organic carrier; mixing a conductive phase, glass, and an inorganic additive to obtain an inorganic mixed powder; (2) The inorganic mixed powder is mixed with the organic carrier, stirred, and then slurried to obtain the resistor slurry.

8. A chip resistor, characterized in that: The chip resistor comprises: a substrate and a resistor layer, wherein the resistor layer is arranged on the surface of the substrate, and the resistor layer is prepared by the resistor paste according to any one of claims 1 to 6.

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