Resistor paste and chip resistor

Abstract

The present invention discloses a resistor paste and a chip resistor. A resistor paste, the conductive phase of which includes lead ruthenate, wherein the content ratio of tetravalent lead to divalent lead in the lead ruthenate is 0.001≤Pb 4+ / Pb 2+ ≤0.155, the ratio of pentavalent ruthenium to tetravalent ruthenium in lead ruthenate is 1.01≤Ru 5+ / Ru 4+ ≤1.45. The present invention controls the Pb in the conductive phase lead ruthenate in the resistor paste. 4+ / Pb 2+ The ratio and Ru 5+ / Ru 4+ When the ratios are within appropriate ranges, the TCR and WTCR performances of the prepared chip resistor can be effectively improved, and the absolute value of the TCR of the chip resistor can be controlled within 100ppm / ℃ and the WTCR≤50ppm / ℃, making it suitable for some high-precision equipment that is highly sensitive to ambient temperature fluctuations.

Description

Technical Field

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

[0002] Chip resistors, as important electronic components, are widely used in thick-film circuits, hybrid integrated circuits, electronic equipment, and other fields. During use, the actual resistance value R of a chip resistor changes due to the influence of the ambient temperature. The temperature coefficient of resistance (TCR) and the width of the temperature coefficient of resistance (WTCR) are generally used to characterize the degree to which the chip resistor's resistance is affected by the ambient temperature. A positive TCR value indicates that the chip resistor's resistance increases with increasing temperature, while a negative TCR value indicates that the chip resistor's resistance decreases with increasing temperature. The larger the absolute value of the TCR, the greater the degree to which the resistance is affected by the ambient temperature, and vice versa. The larger the WTCR value, the greater the resistance fluctuation in different temperature environments, and vice versa. The TCR and WTCR characteristics of chip resistors mainly depend on the resistor layer, which is formed by printing resistor paste on an insulating substrate and sintering it. Therefore, a suitable resistor paste formulation system is required to improve the TCR and WTCR performance of the prepared chip resistors, making them suitable for some high-precision equipment applications that are highly sensitive to ambient temperature fluctuations. Summary of the Invention

[0003] In order to further improve the TCR and WTCR performance of chip resistors, one of the objects of the present invention is to provide a resistor paste, a second object of the present invention is to provide a method for preparing the resistor paste, and a third object of the present invention is to provide a chip resistor.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] The first aspect of the present invention provides a resistor paste, wherein the conductive phase of the resistor paste comprises lead ruthenate, and the ratio of tetravalent lead to divalent lead in the lead ruthenate is 0.001≤Pb 4+ / Pb 2+ ≤0.155, the ratio of pentavalent ruthenium to tetravalent ruthenium in lead ruthenate is 1.01≤Ru 5+ / Ru 4+ ≤1.45.

[0006] Among them, X-ray photoelectron spectroscopy can be used to analyze the chemical state of lead ruthenate and the valence state and ratio of Ru and Pb.

[0007] Preferably, the conductive phase of the resistor paste comprises lead ruthenate, wherein the ratio of tetravalent lead to divalent lead in the lead ruthenate is 0.01≤Pb 4+ / Pb2+ ≤0.155, the ratio of pentavalent ruthenium to tetravalent ruthenium in lead ruthenate is 1.1≤Ru 5+ / Ru 4+ ≤1.45; in some preferred embodiments of the present invention, the ratio of the content of tetravalent lead to divalent lead in lead ruthenate is 0.116, and the ratio of the content of pentavalent ruthenium to tetravalent ruthenium in lead ruthenate is 1.23.

[0008] In the present invention, the lead ruthenate can be prepared by controlling the type and ratio of raw materials (ruthenium source and lead source), as well as the calcination temperature and calcination time during the preparation process, to achieve the purpose of controlling the Pb content in the lead ruthenate powder. 4+ / Pb 2+ Ru 5+ / Ru 4+ content ratio, and the regulation of the specific surface area of ​​lead ruthenate.

[0009] Preferably, the preparation method of lead ruthenate comprises the following steps:

[0010] 1) mixing a ruthenium source and a lead source in a molar ratio of Pb:Ru=1-2, and ball milling;

[0011] 2) drying, grinding, and sieving the mixed raw materials after ball milling;

[0012] 3) calcining the sieved powder, grinding the calcined product again, and sieving it to obtain a finished lead ruthenate powder.

[0013] Further preferably, in the method for preparing lead ruthenate, in step 1), the ruthenium source includes at least one of ruthenium oxide or a ruthenium salt; and the lead source includes at least one of lead oxide or a lead salt.

[0014] Further preferably, in the preparation method of lead ruthenate, in step 1), the ball milling time is 7-20 hours.

[0015] Further preferably, in the preparation method of lead ruthenate, in step 3), the calcination temperature is 320-950°C.

[0016] Further preferably, in the preparation method of lead ruthenate, in step 3), the calcination time is 2-14 hours.

[0017] This resistor paste is composed of 50-70wt% inorganic components and 30-50wt% organic components; the inorganic components include the following components in mass percentage: 15-35wt% conductive phase, 55-75wt% glass and 0.1-10wt% inorganic additives; the organic components include the following components in mass percentage: 3-40wt% resin, 50-90wt% organic solvent and 0.1-10wt% organic additives.

[0018] Preferably, the specific surface area of ​​lead ruthenate in this resistor paste is 2-30m 2 / g; BET can be used to measure the specific surface area of ​​lead ruthenate.

[0019] In the present invention, the specific surface area of ​​the lead ruthenate powder has a certain influence on the WTCR, and the larger the specific surface area, the more negative the TCR. When the specific surface area of ​​the lead ruthenate powder is 2-30m 2 / g can take into account the TCR value and WTCR value in the best range, when the specific surface area is less than 2m 2 / g or >30m 2 / g, the effect of reducing WTCR is limited.

[0020] Preferably, in the resistor paste, the D50 particle size of the lead ruthenate is 0.05-2 μm.

[0021] Preferably, the glass of the resistor paste includes the following components in percentage by mass: 20-70 wt% SiO2, 0.5-60 wt% PbO, 2-25 wt% Al2O3, 0.1-20 wt% MgO, 0-20 wt% CaO, 0-20 wt% SrO, and 0-20 wt% ZnO.

[0022] Preferably, in the resistor paste, the D50 particle size of the glass is 0.5-2 μm.

[0023] Preferably, the inorganic additive of the resistor paste includes at least one of MnO2, CuO, Nb2O5, TiO2, Ta2O5, ZrO2, ZrSiO4, and Al2O3.

[0024] Preferably, in the resistor paste, the D50 particle size of the inorganic additive is 0.5-10 μm.

[0025] Preferably, the resistor paste comprises at least one of the following resins: ethyl cellulose and modified ethyl cellulose, epoxy resin and modified epoxy resin, polyurethane resin and modified polyurethane resin, polyester resin and modified polyester resin, acrylic resin and modified acrylic resin, alkyd resin and modified alkyd resin, phenolic resin and modified phenolic resin, petroleum resin and modified petroleum resin, terpene resin and modified terpene resin, rosin and modified rosin, polyethylene and modified polyethylene, polypropylene and modified polypropylene, polyamide and modified polyamide. The resins used in the present invention are all commonly used resins in the art, and the modified resins are all modified resins prepared by conventional resin modification methods in the art.

[0026] Preferably, the organic solvent of the resistor paste includes at least one of diethylene glycol butyl ether, diethylene glycol butyl ether acetate, tributyl citrate, terpineol, turpentine, isobornyl acetate, benzyl acetate, alcohol ester dodecanol, dibutyl phthalate, toluene, xylene, butanone, cyclohexanone, propylene glycol monomethyl ether, dimethyl phthalate, petroleum ether, and mineral oil.

[0027] Preferably, the organic additives of the resistor paste include a thixotropic agent and a dispersant, the thixotropic agent includes at least one of polyamide wax, hydrogenated castor oil, and organic bentonite; the dispersant includes at least one of fatty acids, aliphatic amides, aliphatic esters, polyamides, and polyacrylates.

[0028] More preferably, the content of the thixotropic agent is 0.05-6 wt % of the organic component.

[0029] More preferably, the content of the dispersant is 0.05-6 wt % of the organic component.

[0030] More preferably, the dispersant includes at least one of oleic acid, stearic acid, vinyl bisstearamide, stearic acid monoglyceride, tristearic acid glyceride, polyamide, and polyacrylate.

[0031] A second aspect of the present invention provides a method for preparing the above-mentioned resistor paste, comprising the following steps:

[0032] (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;

[0033] (2) The inorganic mixed powder is mixed with the organic carrier, stirred, and then slurried to obtain a resistor paste.

[0034] Preferably, in the method for preparing the resistor paste, in step (1), the temperature for mixing and dissolving the resin, organic solvent, and organic additive is 50-120°C.

[0035] Preferably, in the preparation method of this 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 10-480 rpm / min; in some preferred embodiments of the present invention, the stirring speed is 270 rpm / min.

[0036] Preferably, in the preparation method of this resistor slurry, in step (2), the stirring is carried out by straight-blade paddle stirring; further preferably, the stirring speed is 60-720 rpm / min; even more preferably, the stirring speed is 400-720 rpm / min; in some preferred embodiments of the present invention, the stirring speed is 500 rpm / min.

[0037] 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 material is fully dispersed again by a three-roll mill to obtain the resistor paste.

[0038] 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 is prepared from the above-mentioned resistor paste.

[0039] Preferably, the absolute value of TCR of the chip resistor is ≤100 ppm / °C, and the WTCR is ≤50 ppm / °C.

[0040] Preferably, for this chip resistor, the average thickness of the resistance layer on the chip resistor is 2-12 μm; further preferably, the average thickness of the resistance layer on the chip resistor is 4-10 μm; still further preferably, the average thickness of the resistance layer on the chip resistor is 5-8 μm; further preferably, the average thickness of the resistance layer on the chip resistor is 6 μm.

[0041] The present invention also provides a method for preparing the chip resistor, which specifically comprises the following steps: printing a resistor paste on a substrate by a screen printing process, and obtaining a chip resistor after sintering.

[0042] Preferably, in the method for preparing the chip resistor, the substrate is an alumina substrate.

[0043] 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.

[0044] The beneficial effects of the present invention are:

[0045] The present invention controls the Pb content in the conductive phase lead ruthenate in the resistor paste. 4+ / Pb 2+ The ratio and Ru 5+ / Ru 4+When the ratios of are within appropriate ranges, the TCR and WTCR performances of the prepared chip resistor can be effectively improved, and the absolute value of the TCR of the chip resistor can be controlled within 100ppm / ℃ and the WTCR ≤ 50ppm / ℃, making it suitable for some high-precision equipment that is highly sensitive to ambient temperature fluctuations. DETAILED DESCRIPTION

[0046] The present invention will be described in further detail below by way of specific examples. It should be understood that the specific embodiments described in this specification are intended only to explain the present invention and are not intended to limit the present invention. The specific process parameters and the like in the following examples are merely examples within a suitable range, and those skilled in the art can make selections within a suitable range through the description herein, rather than being limited to the specific data exemplified below. The raw materials used in the examples, unless otherwise specified, can be obtained from conventional commercial sources.

[0047] The lead ruthenate used in the following examples and comparative examples had a D50 particle size of 1 μm.

[0048] The glass used in the following examples and comparative examples had a D50 particle size of 1.5 μm.

[0049] The D50 particle size of the inorganic additive in the inorganic component used in the following examples and comparative examples was 1.5 μm.

[0050] The component contents of different glass types used in the following examples and comparative examples are shown in Table 1 below.

[0051] Table 1 Glass component content

[0052]

[0053] The preparation method of lead ruthenate in the following examples and comparative examples is as follows:

[0054] 1. Mix the ruthenium source and the lead source in a molar ratio of Pb:Ru=1-2, and then ball mill for 7-20 hours;

[0055] 2. Place the ball-milled mixed raw materials in an oven and dry them at 70-180°C for 1-12 hours;

[0056] 3. Grind the dried mixed raw materials and sieve them;

[0057] 4. Calcine the sieved powder at a temperature of 320° C. to 950° C. for 2 to 14 hours; grind the calcined product and sieve it again to obtain a finished lead ruthenate powder.

[0058] The Pb content in the prepared lead ruthenate powder can be controlled by controlling the type and ratio of raw materials (ruthenium source and lead source) and the calcination temperature and calcination time during the preparation process. 4+ / Pb 2+ Ru 5+ / Ru 4+ content ratio, and the regulation of the specific surface area of ​​lead ruthenate.

[0059] For example, in Example 3 below, the ruthenium source is ruthenium oxide, the lead source is lead oxide, the ratio of Pb:Ru=1.19, the ball milling time is 15h; the drying temperature is 95℃, the drying time is 4h; the calcination temperature is 800℃, and the calcination time is 8h. Finally, Pb is obtained. 4+ / Pb 2+ is 0.052, Ru 5+ / Ru 4+ is 1.11, and the specific surface area is 16m 2 / g lead ruthenate powder.

[0060] In the following Example 5, the ruthenium source is ruthenium oxide, the lead source is lead oxide, the ratio of Pb:Ru=1.64, the ball milling time is 15h; the drying temperature is 95℃, the drying time is 4h; the calcination temperature is 800℃, and the calcination time is 8h. Finally, Pb 4+ / Pb 2+ is 0.116, Ru 5+ / Ru 4+ is 1.23, and the specific surface area is 16m 2 / g lead ruthenate powder.

[0061] In Example 21 below, the ruthenium source is ruthenium chloride, the lead source is lead acetate, the ratio of Pb:Ru=1.64, the ball milling time is 15h; the drying temperature is 85℃, the drying time is 4h; the calcination temperature is 680℃, and the calcination time is 7h. Finally, Pb 4+ / Pb 2+ is 0.116, Ru 5+ / Ru 4+ is 1.23, and the specific surface area is 29.8m 2 / g lead ruthenate powder.

[0062] Example 1

[0063] The raw materials for preparing the resistor paste of this embodiment are as follows:

[0064] Inorganic components (based on 100wt%): 25wt% lead ruthenate (Pb 4+ / Pb 2+ 0.001, Ru 5+ / Ru 4+is 1.01, and the specific surface area of ​​lead ruthenate is 16m 2 / g), 72wt% G3 glass, 3wt% TiO2;

[0065] Organic components (based on 100 wt%): 17 wt% ethyl cellulose, 77 wt% terpineol, 3 wt% oleic acid, 3 wt% polyamide wax;

[0066] The preparation method of the resistor paste of this embodiment is as follows:

[0067] (1) Mixing and stirring the resin and the organic solvent at 80°C (using a straight-blade paddle at a stirring speed of 270 rpm) to dissolve the resin, then adding an organic additive, filtering, and cooling to obtain a viscous colloidal organic vehicle;

[0068] (2) mixing and dispersing the inorganic components to obtain an inorganic mixed powder;

[0069] (3) The inorganic mixed powder (the inorganic component accounts for 60 wt% of the total component) is added to the organic carrier, stirred (stirring method is straight blade paddle, stirring speed is 580 rpm) for premixing, and then fully dispersed by a three-roll mill to finally obtain a resistor slurry.

[0070] Example 2

[0071] The difference between this embodiment and embodiment 1 is that the lead ruthenate of this embodiment satisfies Pb 4+ / Pb 2+ 0.01, Ru 5+ / Ru 4+ is 1.05.

[0072] Example 3

[0073] The difference between this embodiment and embodiment 1 is that the lead ruthenate of this embodiment satisfies Pb 4+ / Pb 2+ is 0.052, Ru 5+ / Ru 4+ It is 1.11.

[0074] Example 4

[0075] The difference between this embodiment and embodiment 1 is that the lead ruthenate of this embodiment satisfies Pb 4+ / Pb 2+ is 0.094, Ru 5+ / Ru 4+ It is 1.17.

[0076] Example 5

[0077] The difference between this embodiment and embodiment 1 is that the lead ruthenate of this embodiment satisfies Pb 4+ / Pb 2+ is 0.116, Ru 5+ / Ru 4+ It is 1.23.

[0078] Example 6

[0079] The difference between this embodiment and embodiment 1 is that the lead ruthenate of this embodiment satisfies Pb 4+ / Pb 2+ is 0.131, Ru 5+ / Ru 4+ is 1.3, and ethyl cellulose is replaced by modified ethyl cellulose.

[0080] Example 7

[0081] The difference between this embodiment and embodiment 6 is that the lead ruthenate of this embodiment satisfies Pb 4+ / Pb 2+ is 0.145, Ru 5+ / Ru 4+ It is 1.39.

[0082] Example 8

[0083] The difference between this embodiment and embodiment 6 is that the lead ruthenate of this embodiment satisfies Pb 4+ / Pb 2+ is 0.155, Ru 5+ / Ru 4+ is 1.45.

[0084] Example 9

[0085] The raw materials for preparing the resistor paste of this embodiment are as follows:

[0086] Inorganic components (based on 100wt%): 15wt% lead ruthenate (Pb 4+ / Pb 2+ is 0.116, Ru 5+ / Ru 4+ is 1.23, and the specific surface area of ​​lead ruthenate is 16m 2 / g), 75wt% G1 glass, 10wt% ZrO2;

[0087] Organic components (based on 100 wt%): 3.2 wt% phenolic resin, 89.8 wt% diethylene glycol butyl ether, 6 wt% polyamide, 1 wt% hydrogenated castor oil;

[0088] The preparation method of the resistor paste of this embodiment is as follows:

[0089] (1) Mixing and stirring the resin and the organic solvent at 80°C (using a straight-blade paddle at a stirring speed of 270 rpm) to dissolve the resin, then adding an organic additive, filtering, and cooling to obtain a viscous colloidal organic vehicle;

[0090] (2) mixing and dispersing the inorganic components to obtain an inorganic mixed powder;

[0091] (3) The inorganic mixed powder (the inorganic component accounts for 60 wt% of the total component) is added to the organic carrier, stirred (stirring method is straight blade paddle, stirring speed is 580 rpm) for premixing, and then fully dispersed by a three-roll mill to finally obtain a resistor slurry.

[0092] Example 10

[0093] The raw materials for preparing the resistor paste of this embodiment are as follows:

[0094] Inorganic components (based on 100 wt%): 18.7 wt% lead ruthenate (Pb 4+ / Pb 2+ is 0.116, Ru 5+ / Ru 4+ is 1.23, and the specific surface area of ​​lead ruthenate is 16m 2 / g), 73.3wt% G2 glass, 8wt% CuO;

[0095] Organic components (based on 100 wt%): 28.4 wt% alkyd resin, 64.6 wt% benzyl acetate, 5.1 wt% vinyl bisstearamide, 1.9 wt% hydrogenated castor oil;

[0096] The preparation method of the resistor paste of this embodiment is as follows:

[0097] (1) Mixing and stirring the resin and the organic solvent at 80°C (using a straight-blade paddle at a stirring speed of 270 rpm) to dissolve the resin, then adding an organic additive, filtering, and cooling to obtain a viscous colloidal organic vehicle;

[0098] (2) mixing and dispersing the inorganic components to obtain an inorganic mixed powder;

[0099] (3) The inorganic mixed powder (the inorganic component accounts for 60 wt% of the total component) is added to the organic carrier, stirred (stirring method is straight blade paddle, stirring speed is 580 rpm) for premixing, and then fully dispersed by a three-roll mill to finally obtain a resistor slurry.

[0100] Example 11

[0101] The raw materials for preparing the resistor paste of this embodiment are as follows:

[0102] Inorganic components (based on 100wt%): 30.6wt% lead ruthenate (Pb 4+ / Pb 2+ is 0.116, Ru 5+ / Ru 4+ is 1.23, and the specific surface area of ​​lead ruthenate is 16m 2 / g), 64.4wt% G4 glass, 5wt% Nb2O5;

[0103] Organic components (based on 100 wt%): 12.3 wt% acrylic resin, 82.8 wt% dibutyl phthalate, 4.84 wt% polyacrylate, 0.06 wt% organic bentonite;

[0104] The preparation method of the resistor paste of this embodiment is as follows:

[0105] (1) Mixing and stirring the resin and the organic solvent at 80°C (using a straight-blade paddle at a stirring speed of 270 rpm) to dissolve the resin, then adding an organic additive, filtering, and cooling to obtain a viscous colloidal organic vehicle;

[0106] (2) mixing and dispersing the inorganic components to obtain an inorganic mixed powder;

[0107] (3) The inorganic mixed powder (the inorganic component accounts for 50 wt% of the total component) is added to the organic carrier, stirred (stirring method is straight blade paddle, stirring speed is 580 rpm) pre-mixed, and then fully dispersed by a three-roll mill to finally obtain a resistor slurry.

[0108] Example 12

[0109] The raw materials for preparing the resistor paste of this embodiment are as follows:

[0110] Inorganic components (based on 100wt%): 32.9wt% lead ruthenate (Pb 4+ / Pb 2+ is 0.116, Ru 5+ / Ru 4+ is 1.23, and the specific surface area of ​​lead ruthenate is 16m 2 / g), 66.9wt% G5 glass, 0.2wt% Ta2O5;

[0111] Organic components (based on 100 wt%): 36.1 wt% modified rosin, 56.4 wt% turpentine, 2.4 wt% stearic acid, 5.1 wt% organic bentonite;

[0112] The preparation method of the resistor paste of this embodiment is as follows:

[0113] (1) Mixing and stirring the resin and the organic solvent at 80°C (using a straight-blade paddle at a stirring speed of 270 rpm) to dissolve the resin, then adding an organic additive, filtering, and cooling to obtain a viscous colloidal organic vehicle;

[0114] (2) mixing and dispersing the inorganic components to obtain an inorganic mixed powder;

[0115] (3) The inorganic mixed powder (the inorganic component accounts for 55 wt% of the total component) is added to the organic carrier, stirred (stirring method is straight blade paddle, stirring speed is 580 rpm) pre-mixed, and then fully dispersed by a three-roll mill to finally obtain a resistor slurry.

[0116] Example 13

[0117] The raw materials for preparing the resistor paste of this embodiment are as follows:

[0118] Inorganic components (based on 100wt%): 35wt% lead ruthenate (Pb 4+ / Pb 2+ is 0.116, Ru 5+ / Ru 4+ is 1.23, and the specific surface area of ​​lead ruthenate is 16m 2 / g), 55wt% G3 glass, 10wt% MnO2;

[0119] Organic components (based on 100 wt%): 40 wt% resin (polyurethane resin and modified rosin mixed in a 1:1 mass ratio), 50 wt% isobornyl acetate, 4 wt% stearic acid monoglyceride, 6 wt% thixotropic agent (hydrogenated castor oil and polyamide wax mixed in a 1:1 mass ratio);

[0120] The preparation method of the resistor paste of this embodiment is as follows:

[0121] (1) Mixing and stirring the resin and the organic solvent at 80°C (using a straight-blade paddle at a stirring speed of 270 rpm) to dissolve the resin, then adding an organic additive, filtering, and cooling to obtain a viscous colloidal organic vehicle;

[0122] (2) mixing and dispersing the inorganic components to obtain an inorganic mixed powder;

[0123] (3) The inorganic mixed powder (the inorganic component accounts for 65wt% of the total component) is added to the organic carrier, stirred (stirring method is straight blade paddle, stirring speed is 580 rpm) for premixing, and then fully dispersed by a three-roll mill to finally obtain a resistor slurry.

[0124] Example 14

[0125] The raw materials for preparing the resistor paste of this embodiment are as follows:

[0126] Inorganic components (based on 100wt%): 25wt% lead ruthenate (Pb 4+ / Pb 2+ is 0.116, Ru 5+ / Ru 4+ is 1.23, and the specific surface area of ​​lead ruthenate is 16m 2 / g), 72wt% G3 glass, 3wt% TiO2;

[0127] Organic components (based on 100 wt%): 20.3 wt% resin (ethyl cellulose and terpene resin mixed in a 2:1 mass ratio), 73.7 wt% organic solvent (dodecyl alcohol ester and tributyl citrate mixed in a 1:1 mass ratio), 3 wt% glyceryl tristearate, 3 wt% polyamide wax;

[0128] The preparation method of the resistor paste of this embodiment is as follows:

[0129] (1) Mixing and stirring the resin and the organic solvent at 80°C (using a straight-blade paddle at a stirring speed of 270 rpm) to dissolve the resin, then adding an organic additive, filtering, and cooling to obtain a viscous colloidal organic vehicle;

[0130] (2) mixing and dispersing the inorganic components to obtain an inorganic mixed powder;

[0131] (3) The inorganic mixed powder (the inorganic component accounts for 70 wt% of the total component) is added to the organic carrier, stirred (stirring method is straight blade paddle, stirring speed is 580 rpm) pre-mixed, and then fully dispersed by a three-roll mill to finally obtain a resistor slurry.

[0132] Example 15

[0133] The raw materials for preparing the resistor paste of this embodiment are as follows:

[0134] Inorganic components (based on 100wt%): 25wt% lead ruthenate (Pb 4+ / Pb 2+ is 0.145, Ru 5+ / Ru 4+ is 1.39, and the specific surface area of ​​lead ruthenate is 16m 2 / g), 72wt% glass (G2 and G3 are mixed in a mass ratio of 1:1), 3wt% Al2O3;

[0135] Organic components (based on 100 wt%): 17 wt% modified polypropylene, 77 wt% tributyl citrate, 3 wt% oleic acid, 3 wt% hydrogenated castor oil;

[0136] The preparation method of the resistor paste of this embodiment is as follows:

[0137] (1) Mixing and stirring the resin and the organic solvent at 80°C (using a straight-blade paddle at a stirring speed of 270 rpm) to dissolve the resin, then adding an organic additive, filtering, and cooling to obtain a viscous colloidal organic vehicle;

[0138] (2) mixing and dispersing the inorganic components to obtain an inorganic mixed powder;

[0139] (3) The inorganic mixed powder (the inorganic component accounts for 60 wt% of the total component) is added to the organic carrier, stirred (stirring method is straight blade paddle, stirring speed is 580 rpm) for premixing, and then fully dispersed by a three-roll mill to finally obtain a resistor slurry.

[0140] Example 16

[0141] The raw materials for preparing the resistor paste of this embodiment are as follows:

[0142] Inorganic components (based on 100wt%): 21.5wt% lead ruthenate (Pb 4+ / Pb 2+ is 0.145, Ru 5+ / Ru 4+ is 1.39, and the specific surface area of ​​lead ruthenate is 16m 2 / g), 70wt% glass (G1 and G3 are mixed in a mass ratio of 1:1), 8.5wt% ZrSiO4;

[0143] Organic component (based on 100 wt%): 26.8 wt% modified polyamide, 73.07 wt% organic solvent (diethylene glycol butyl ether and petroleum ether mixed in a mass ratio of 2:1), 0.06 wt% stearic acid, 0.07 wt% polyamide wax;

[0144] The preparation method of the resistor paste of this embodiment is as follows:

[0145] (1) Mixing and stirring the resin and the organic solvent at 80°C (using a straight-blade paddle at a stirring speed of 270 rpm) to dissolve the resin, then adding an organic additive, filtering, and cooling to obtain a viscous colloidal organic vehicle;

[0146] (2) mixing and dispersing the inorganic components to obtain an inorganic mixed powder;

[0147] (3) The inorganic mixed powder (the inorganic component accounts for 60 wt% of the total component) is added to the organic carrier, stirred (stirring method is straight blade paddle, stirring speed is 580 rpm) for premixing, and then fully dispersed by a three-roll mill to finally obtain a resistor slurry.

[0148] Example 17

[0149] The raw materials for preparing the resistor paste of this embodiment are as follows:

[0150] Inorganic components (based on 100wt%): 30.6wt% lead ruthenate (Pb 4+ / Pb 2+ is 0.116, Ru 5+ / Ru 4+ is 1.23, and the specific surface area of ​​lead ruthenate is 16m 2 / g), 64.4wt% glass (G3 and G5 are mixed in a mass ratio of 2:1), 5wt% inorganic additives (TiO2 and CuO are mixed in a mass ratio of 1:1);

[0151] Organic components (based on 100 wt%): 12.3 wt% modified epoxy resin, 82.8 wt% terpineol, 4.4 wt% polyacrylate, 0.5 wt% hydrogenated castor oil;

[0152] The preparation method of the resistor paste of this embodiment is as follows:

[0153] (1) Mixing and stirring the resin and the organic solvent at 80°C (using a straight-blade paddle at a stirring speed of 270 rpm) to dissolve the resin, then adding an organic additive, filtering, and cooling to obtain a viscous colloidal organic vehicle;

[0154] (2) mixing and dispersing the inorganic components to obtain an inorganic mixed powder;

[0155] (3) The inorganic mixed powder (the inorganic component accounts for 50 wt% of the total component) is added to the organic carrier, stirred (stirring method is straight blade paddle, stirring speed is 580 rpm) pre-mixed, and then fully dispersed by a three-roll mill to finally obtain a resistor slurry.

[0156] Example 18

[0157] The difference between this embodiment and embodiment 5 is that the specific surface area of ​​lead ruthenate in this embodiment is 2m 2 / g.

[0158] Example 19

[0159] The difference between this embodiment and embodiment 5 is that the specific surface area of ​​lead ruthenate in this embodiment is 11.2 m 2 / g.

[0160] Example 20

[0161] The difference between this embodiment and embodiment 5 is that the specific surface area of ​​lead ruthenate in this embodiment is 20.8m 2 / g.

[0162] Example 21

[0163] The difference between this embodiment and embodiment 5 is that the specific surface area of ​​lead ruthenate in this embodiment is 29.8m 2 / g.

[0164] Example 22

[0165] The difference between this embodiment and embodiment 5 is that the specific surface area of ​​lead ruthenate in this embodiment is 1.9 m 2 / g.

[0166] Example 23

[0167] The difference between this embodiment and embodiment 5 is that the specific surface area of ​​lead ruthenate in this embodiment is 31m 2 / g.

[0168] Comparative Example 1

[0169] The difference between this example and Example 1 is that the lead ruthenate in this example satisfies (Pb 4+ / Pb 2+ 0.0009, Ru 5+ / Ru 4+ is 1.008).

[0170] Comparative Example 2

[0171] The difference between this example and Example 1 is that the lead ruthenate in this example satisfies (Pb 4+ / Pb 2+ is 0.156, Ru 5+ / Ru 4+ is 1.47).

[0172] Comparative Example 3

[0173] The difference between this example and Example 1 is that the lead ruthenate in this example satisfies (Pb 4+ / Pb 2+ is 0, Ru 5+ / Ru 4+ is 1).

[0174] The resistor pastes prepared in the above embodiments and comparative examples were printed on an alumina substrate by screen printing and sintered at 850° C. to obtain a chip resistor. The dimensions of the resistor layer on the chip resistor were: 0.8 mm in length, 0.5 mm in width, and 6 μm in average thickness.

[0175] The chip resistors prepared from the resistor pastes prepared in the above examples and comparative examples were subjected to temperature coefficient of resistance (TCR) testing. The TCR includes the temperature coefficient of resistance in the high temperature range (HTCR) and the temperature coefficient of resistance in the low temperature range (CTCR). The temperature coefficient of resistance width (WTCR) was obtained by calculation, WTCR = |HTCR - CTCR|. The test results are shown in Table 2 below.

[0176] The CTCR test method is as follows: the chip resistors of the embodiment and the comparative example are kept at constant temperatures of 25° C. and −55° C. for 10 minutes, the resistance of the samples is tested, and the CTCR is calculated.

[0177] Where R -55 Indicates the resistance value at a constant temperature of -55°C, R 25 Indicates the resistance value at a constant temperature of 25°C.

[0178] The HTCR test method is as follows: the chip resistors of the embodiment and the comparative example are kept at constant temperatures of 25° C. and 125° C. for 10 minutes, the resistance of the samples is tested, and the HTCR is calculated.

[0179] Where R 125 Indicates the resistance value at a constant temperature of 125°C, R 25 Indicates the resistance value at a constant temperature of 25°C.

[0180] Table 2 Performance test results of the embodiments and comparative examples

[0181]

[0182]

[0183] The resistance of a chip resistor mainly depends on the resistor layer, and the conductive mechanism of the resistor layer includes three situations: metallic conduction mechanism, tunnel barrier conduction mechanism, or the coexistence of metallic conduction mechanism and tunnel barrier conduction mechanism. Among them, under the metallic conduction mechanism, as the operating environment temperature of the resistor rises, the resistance of the resistor increases, that is, the TCR is a positive value; under the tunnel barrier conduction mechanism, as the operating environment temperature of the resistor rises, the resistance of the resistor decreases, that is, the TCR is a negative value.

[0184] When the lead ruthenate in the resistor paste for preparing the resistor layer meets the requirements of Pb 4+ / Pb 2+ =0, Ru 5+ / Ru 4+ =1, only metallic conduction mechanism exists in the resistor layer. In the high temperature range (25℃ to 125℃), the electronic conduction is affected as the temperature rises, resulting in an increase in resistance. In the low temperature range (-55℃ to 25℃), the electronic conduction is less affected by temperature changes. At this time, the WTCR of the chip resistor is larger.

[0185] When the lead ruthenate in the resistor paste for preparing the resistor layer satisfies 0.001≤Pb 4+ / Pb 2+ ≤0.155, and 1.01≤Ru 5+ / Ru 4+ When ≤1.45, the resistance layer has both metallic conduction mechanism and tunnel barrier conduction mechanism; in the high temperature range (25℃ to 125℃), the energy provided by the external temperature increase is sufficient to enable electrons to cross the potential barrier, so the tunnel barrier conduction mechanism reduces the resistance, thereby suppressing the metallic conduction mechanism whose resistance increases with increasing temperature, and reducing the final HTCR value of the resistor; in the low temperature range (-55℃ to 25℃), the energy provided by the external temperature increase is difficult to enable electrons to cross the potential barrier, and the electron conduction is less affected by temperature changes, so that the final CTCR value of the resistor does not change much; therefore, when the lead ruthenate in the resistor paste meets the above conditions, the WTCR value of the prepared chip resistor is reduced to within 50ppm / ℃.

[0186] When the lead ruthenate in the resistor paste for preparing the resistor layer satisfies 0<Pb 4+ / Pb 2+ <0.001, and 1 <Ru 5+ / Ru 4+ When WTCR is less than 1.01, the WTCR of the prepared chip resistor is reduced, but still cannot meet the requirement of less than 50 ppm / °C.

[0187] When the lead ruthenate in the resistor paste for preparing the resistor layer meets the requirements of Pb 4+ / Pb 2+ >0.155, and Ru 5+ / Ru 4+ When ≥1.45, in the high temperature range (25°C to 125°C), the tunnel barrier is large enough, and the energy provided by the external temperature increase cannot enable electrons to cross the barrier. Therefore, the resistance layer is dominated by the metallic conduction mechanism again, and the WTCR increases.

[0188] From the data of the above examples and comparative examples, it can be seen that Pb in the conductive phase lead ruthenate 4+ / Pb 2+ The ratio and Ru 5+ / Ru 4+ When the ratios of are within appropriate ranges, the TCR and WTCR performances of the prepared chip resistor can be effectively improved, and the absolute value of the TCR of the chip resistor can be controlled within 100ppm / ℃ and the WTCR≤50ppm / ℃, making it suitable for some high-precision equipment that is highly sensitive to ambient temperature fluctuations.

[0189] 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 considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A resistor paste, characterized in that: The conductive phase of the resistor paste includes lead ruthenate, and the content ratio of tetravalent lead to divalent lead in the lead ruthenate is 0.001≤Pb 4+ / Pb 2+ ≤0.155, the ratio of pentavalent ruthenium to tetravalent ruthenium in lead ruthenate is 1.01≤Ru 5+ / Ru 4+ ≤1.

45.

2. The resistor paste according to claim 1, characterized in that: The resistor paste is composed of 50-70wt% inorganic components and 30-50wt% organic components; the inorganic components include the following components in mass percentage: 15-35wt% conductive phase, 55-75wt% glass and 0.1-10wt% inorganic additives; the organic components include the following components in mass percentage: 3-40wt% resin, 50-90wt% organic solvent and 0.1-10wt% organic additives.

3. The resistor paste according to claim 1 or 2, characterized in that: The specific surface area of ​​the lead ruthenate is 2-30m 2 / g.

4. The resistor paste according to claim 2, characterized in that: The glass comprises the following components in percentage by mass: 20-70wt% SiO2, 0.5-60wt% PbO, 2-25wt% Al2O3, 0.1-20wt% MgO, 0-20wt% CaO, 0-20wt% SrO, and 0-20wt% ZnO.

5. The resistor paste according to claim 2, characterized in that: The inorganic additive includes at least one of MnO2, CuO, Nb2O5, TiO2, Ta2O5, ZrO2, ZrSiO4, and Al2O3.

6. The resistor paste according to claim 2, characterized in that: The resin includes at least one of ethyl cellulose, modified ethyl cellulose, epoxy resin, modified epoxy resin, polyurethane resin, modified polyurethane resin, polyester resin, modified polyester resin, acrylic resin, modified acrylic resin, alkyd resin, modified alkyd resin, phenolic resin, modified phenolic resin, petroleum resin, modified petroleum resin, terpene resin, modified terpene resin, rosin, modified rosin, polyethylene, modified polyethylene, polypropylene, modified polypropylene, polyamide, and modified polyamide.

7. The resistor paste according to claim 2, characterized in that: The organic solvent includes at least one of diethylene glycol butyl ether, diethylene glycol butyl ether acetate, tributyl citrate, terpineol, turpentine, isobornyl acetate, benzyl acetate, alcohol ester dodecaned, dibutyl phthalate, toluene, xylene, butanone, cyclohexanone, propylene glycol monomethyl ether, dimethyl phthalate, petroleum ether, and mineral oil.

8. The resistor paste according to claim 2, characterized in that: The organic additive comprises a thixotropic agent and a dispersant. The thixotropic agent comprises at least one of polyamide wax, hydrogenated castor oil and organic bentonite; the dispersant comprises at least one of fatty acids, aliphatic amides, aliphatic esters, polyamide and polyacrylate.

9. The method for preparing a resistor paste according to any one of claims 2 to 8, 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 and the organic carrier are mixed, stirred, and then slurried to obtain the resistor slurry.

10. 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 8.

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