Resistor paste, chip resistors and glass particles

Abstract

To provide a resistor paste capable of achieving both high resistivity and low TCR of a resistor.SOLUTION: The resistor paste includes metal particles, insulating particles, glass particles, and metal silicide. The metal particles contain copper and nickel. The insulating particles contain at least one of alumina, zirconia, zinc oxide, and boron nitride. A chip resistor 1 includes a resistor 13 and a substrate 11. The resistor 13 is formed on the substrate 11 using the above-mentioned resistor paste as a material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates generally to resistor pastes, chip resistors, and glass particles, and more particularly to resistor pastes containing metal particles, chip resistors having resistors made from resistor pastes, and glass particles contained in resistor pastes. [Background technology]

[0002] Patent Document 1 describes a resistor paste containing a conductive portion formed of metal particles, an inorganic binder component formed of low-melting-point glass particles, a resistance-adjusting component formed of non-conductive inorganic particles (insulating particles), and an organic vehicle. The metal particles include copper and nickel. The non-conductive inorganic particles include, for example, alumina. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-46567 Summary of the Invention [Problem to be solved by the invention]

[0004] In the resistor paste described in Patent Document 1, the resistivity of a resistor made from the resistor paste can be increased by adding a resistance-adjusting component, but if the amount of resistance-adjusting component added is increased in an attempt to further increase the resistivity, the temperature coefficient of resistance (hereinafter referred to as "TCR") of the resistor may become too low.

[0005] An object of the present disclosure is to provide a resistor paste, a chip resistor, and glass particles that can achieve both high resistivity and low TCR for the resistor. [Means for solving the problem]

[0006] A resistor paste according to one embodiment of the present disclosure includes metal particles, insulating particles, glass particles, and a metal silicide. The metal particles include copper and nickel. The insulating particles include at least one of alumina, zirconia, zinc oxide, and boron nitride.

[0007] A resistor paste according to another embodiment of the present disclosure includes metal particles, insulating particles, a metal silicide, and glass particles. The metal particles include copper and nickel. The insulating particles include at least one of alumina, zirconia, zinc oxide, and boron nitride. The glass particles include at least boron oxide and aluminum oxide. When a resistor for a chip resistor is formed, nickel compounds including nickel silicide are produced.

[0008] A chip resistor according to one aspect of the present disclosure includes a resistor and a substrate, the resistor being formed on the substrate using the resistor paste as a material.

[0009] The glass particles according to one embodiment of the present disclosure are used in the resistor paste. [Effects of the Invention]

[0010] According to the resistor paste, chip resistor, and glass particles according to one embodiment of the present disclosure, it is possible to achieve both high resistivity and low TCR for the resistor. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a chip resistor including a resistor made of the resistor paste according to the first and second embodiments. [Figure 2] FIG. 2 is a graph showing the relationship between the ratio of glass particles B to the total of glass particles A and B contained in the resistor paste according to the second embodiment and TCR. DETAILED DESCRIPTION OF THE INVENTION

[0012] The resistor paste, chip resistor, and glass particles according to embodiments 1 and 2 will be described below with reference to the drawings. Figure 1, which is referred to in the following embodiments 1 and 2, is a schematic diagram, and the ratios of the sizes and thicknesses of the components in the figure do not necessarily reflect the actual dimensional ratios.

[0013] (Embodiment 1) (1) Resistor paste composition First, the configuration of the resistor paste according to the first embodiment will be described.

[0014] The resistor paste according to the first embodiment is the material for the resistor 13 (see FIG. 1) of the chip resistor 1 described below, and is used to form the resistor 13.

[0015] The resistor paste according to the first embodiment contains metal particles, insulating particles, glass particles, an organic vehicle, and a metal silicide.

[0016] The metal particles include copper (Cu) and nickel (Ni). More specifically, the metal particles are a combination of copper particles and nickel particles. The metal particles are not limited to a combination of copper particles and nickel particles, but may also be alloy particles of copper and nickel. Furthermore, the metal particles may be a combination of copper particles and alloy particles, a combination of nickel particles and alloy particles, or a combination of copper particles, nickel particles and alloy particles. The metal particles form a conductive path in the resistor 13 (see FIG. 1) after firing. The metal particles may contain copper and nickel, and may further contain other metals.

[0017] The insulating particles contain at least one of alumina (Al2O3), zirconia (ZrO2), zinc oxide (ZnO), and boron nitride (BN). In the resistor paste according to embodiment 1, the insulating particles contain alumina. The insulating particles reduce the content of metal particles in the fired resistor 13 (see FIG. 1) to increase the resistance value, while suppressing the melting and flow of glass particles (described below) to prevent disconnection of the conductive path.

[0018] The glass particles include, for example, silicon oxide (e.g., SiO2). The glass particles may include other oxides in addition to silicon oxide. The other oxides are, for example, boron oxide (BO3). The glass particles improve the wettability and adhesion to the substrate 11 (see FIG. 1) described below, and melt and solidify throughout the resistor 13 to form a strong resistor 13. Furthermore, the glass particles are an insulator, and therefore also have the function of adjusting the resistance value.

[0019] The organic vehicle contains, for example, at least one of an organic binder and an organic solvent. In the resistor paste according to embodiment 1, the organic vehicle contains both an organic binder and an organic solvent. Examples of the organic binder include cellulose-based resins and acrylic-based resins. Examples of the organic solvent include terpineol and butyl carbitol acetate. The mass ratio of the organic vehicle, relative to 100 parts by mass of the metal particles, is preferably, for example, 5 to 200 parts by mass, more preferably 10 to 150 parts by mass, and even more preferably 20 to 100 parts by mass.

[0020] The resistor paste contains at least one of titanium silicide (TiSi2), zirconium silicide (ZrSi2), hafnium silicide (HfSi2), niobium silicide (NbSi2), tantalum silicide (TaSi2), chromium silicide (CrSi2), tungsten silicide (WSi2), molybdenum silicide (MoSi2), iron silicide (FeSi2), magnesium silicide (Mg2Si), sodium silicide (Na2Si), and platinum silicide (PtSi) as a metal silicide. The resistor paste according to the first embodiment contains titanium silicide as a metal silicide.

[0021] In the resistor paste according to the first embodiment, the metal silicide reacts with the metal particles (copper and nickel) upon firing, and this reaction changes the composition of copper and nickel in the metal particles, and nickel silicide (Ni 31 Si 12As a result, it is possible to increase the TCR of resistor 13 (see FIG. 1) formed by firing. In other words, it is possible to suppress the decrease in TCR that occurs with an increase in the amount of insulating particles added.

[0022] (2) Chip resistor configuration Next, the configuration of the chip resistor 1 according to the first embodiment will be described with reference to FIG.

[0023] 1, the chip resistor 1 according to the first embodiment includes a substrate 11, a plurality of (two in the illustrated example) upper surface electrodes 12, a resistor 13, a protective film 14, a plurality of (two in the illustrated example) lower surface electrodes 15, and a plurality of (two in the illustrated example) end surface electrodes 16. The chip resistor 1 according to the first embodiment also includes a plurality of (two in the illustrated example) first plating layers 17, a plurality of (two in the illustrated example) second plating layers 18, and a plurality of (two in the illustrated example) third plating layers 19. That is, the chip resistor 1 according to the first embodiment includes the substrate 11 and the resistor 13.

[0024] (2.1) Substrate The substrate 11 is, for example, a ceramic substrate. The material of the ceramic substrate is, for example, an alumina sintered body with an alumina content of 96% or more. The substrate 11 is formed in a rectangular shape when viewed from a first direction D1. As shown in FIG. 1, the substrate 11 has a first main surface (upper surface) 111, a second main surface (lower surface) 112, and an outer peripheral surface 113. The first main surface 111 and the second main surface 112 face each other in the first direction D1. Each of the first main surface 111 and the second main surface 112 is a flat surface extending along a second direction D2 perpendicular to the first direction D1. The outer peripheral surface 113 includes four side surfaces extending along the first direction D1. The first direction D1 is parallel to the thickness direction of the substrate 11 (the vertical direction in FIG. 1). The second direction D2 is parallel to the longitudinal direction or width direction (short-side direction) of the substrate 11 (the horizontal direction in FIG. 1).

[0025] (2.2)Top electrode The plurality of upper surface electrodes 12 are formed on the first main surface 111 of the substrate 11. In the example of Fig. 1, the plurality of upper surface electrodes 12 are formed on both ends of the first main surface 111 of the substrate 11 in the second direction D2. The material of the plurality of upper surface electrodes 12 is, for example, a Cu (copper) alloy. The plurality of upper surface electrodes 12 are formed, for example, by printing a thick film material and then firing it.

[0026] (2.3) Resistor The resistor 13 is formed on the first main surface 111 of the substrate 11. In the example of FIG. 1, the resistor 13 is formed in the center of the first main surface 111 of the substrate 11. The material of the resistor 13 is, for example, the resistor paste described above. The resistor 13 is in contact with the plurality of upper surface electrodes 12 at both ends in the second direction D2 and is electrically connected to the plurality of upper surface electrodes 12. The resistor 13 has, for example, a rectangular shape when viewed in a plan view from the first direction D1, but can have any shape depending on the resistance value of the resistor 13.

[0027] (2.4) Protective film The protective film 14 is a film for protecting the resistor 13. The protective film 14 covers at least a portion of the resistor 13. In the example of FIG. 1, the protective film 14 covers the entire area (whole) of the resistor 13. The material of the protective film 14 is, for example, epoxy resin. The protective film 14 is formed, for example, in a rectangular shape when viewed from a plane in the first direction D1, but can have any shape to match the shape of the resistor 13. The material of the protective film 14 is not limited to epoxy resin, and may be, for example, polyimide resin.

[0028] (2.5) Bottom electrode A plurality of lower electrodes (rear electrodes) 15 are formed on the second main surface 112 of the substrate 11. In the example of FIG. 1, the plurality of lower electrodes 15 are formed on both ends of the second main surface 112 of the substrate 11 in the second direction D2. The plurality of lower electrodes 15 correspond one-to-one to the plurality of upper electrodes 12. The material of the plurality of lower electrodes 15 is, for example, a Cu-based alloy. The plurality of lower electrodes 15 are formed, for example, by printing a thick film material and then firing it.

[0029] (2.6) End electrode The multiple end electrodes 16 are formed to cover the outer peripheral surface 113 of the substrate 11. In the example of FIG. 1, the multiple end electrodes 16 are formed to cover both side surfaces in the second direction D2 of the four side surfaces included in the outer peripheral surface 113 of the substrate 11. The multiple end electrodes 16 correspond one-to-one to the multiple upper electrodes 12 and the multiple lower electrodes 15. The multiple end electrodes 16 are made of, for example, a mixture of carbon powder, silver (Ag), and epoxy resin. Each of the multiple end electrodes 16 contacts a corresponding upper electrode 12 among the multiple upper electrodes 12 at a first end (upper end) in the first direction D1, and contacts a corresponding lower electrode 15 among the multiple lower electrodes 15 at a second end (lower end). This electrically connects the multiple upper electrodes 12 and the multiple lower electrodes 15 via the multiple end electrodes 16.

[0030] (2.7) First plating layer The multiple first plating layers 17 are made of, for example, copper (Cu) plating. In the example of FIG. 1, the multiple first plating layers 17 cover the multiple upper electrodes 12, the multiple lower electrodes 15, and the multiple end electrodes 16 at both ends of the substrate 11 in the second direction D2. The multiple first plating layers 17 are in contact with the surface of the protective film 14. In the chip resistor 1 according to embodiment 1, providing the first plating layers 17 makes it possible to adjust the resistance value of the chip resistor 1. Note that the first plating layers 17 may be omitted.

[0031] (2.8) Second plating layer The second plating layers 18 are made of, for example, nickel (Ni) plating. In the example of Fig. 1, the second plating layers 18 cover the first plating layers 17 at both ends of the substrate 11 in the second direction D2. The second plating layers 18 are also in contact with the surface of the protective film 14.

[0032] (2.9) Third plating layer The third plating layers 19 are made of, for example, tin (Sn) plating. In the example of Fig. 1, the third plating layers 19 cover the second plating layers 18 at both ends of the substrate 11 in the second direction D2. The third plating layers 19 are also in contact with the surface of the protective film 14.

[0033] (3) Manufacturing method of chip resistors Next, a method for manufacturing the chip resistor 1 according to the first embodiment will be described.

[0034] The method for manufacturing the chip resistor 1 according to the first embodiment includes first to ninth steps.

[0035] In the first step, the substrate 11 is prepared. More specifically, in the first step, a substrate body that will be the basis for each of the substrates 11 of the multiple chip resistors 1 is prepared. The substrate body is, for example, a ceramic substrate. The material of the ceramic substrate that will be the substrate body is, for example, an alumina sintered body with an alumina content of 96% or more.

[0036] In the second step, a plurality of lower electrodes 15 for each of the plurality of chip resistors 1 are formed on the second main surface of the substrate body. More specifically, in the second step, a Cu-based alloy film is formed on the second main surface of the substrate body by, for example, printing a thick film material and then firing it, thereby forming a plurality of lower electrodes 15 for each of the plurality of chip resistors 1. The second main surface of the substrate body is the surface that becomes the second main surface 112 of the substrate 11 of each of the plurality of chip resistors 1.

[0037] In the third step, a plurality of upper surface electrodes 12 are formed on the first main surface of the substrate body. The first main surface of the substrate body is a surface that becomes the first main surface 111 of each of the substrates 11 of the plurality of chip resistors 1. More specifically, in the third step, a Cu-based alloy film is formed on the first main surface of the substrate body by, for example, printing a thick film material and then firing it, thereby forming the plurality of upper surface electrodes 12 on each of the plurality of chip resistors 1.

[0038] In the fourth step, the resistor 13 of each of the multiple chip resistors 1 is formed. More specifically, in the fourth step, a resistor paste is printed on the first main surface of the substrate body, and then the resistor 13 is formed by firing. At this time, in the resistor 13, a metal silicide (titanium silicide) reacts with metal particles (copper and nickel), thereby generating a metal silicide (nickel silicide) different from the metal silicide (titanium silicide). That is, in the chip resistor 1 according to the first embodiment, the resistor 13 contains nickel silicide.

[0039] In the fifth step, a protective film 14 is formed on each of the plurality of chip resistors 1. More specifically, in the fifth step, an epoxy resin is applied so as to cover the entire resistor 13, and then the epoxy resin is thermally cured to form the protective film 14. As shown in FIG. 1, the protective film 14 also covers the contact portions between the plurality of upper surface electrodes 12 and the resistor 13.

[0040] In the sixth step, the plurality of chip resistors formed integrally in the first to fifth steps, excluding the end surface electrodes 16, the first plating layer 17, the second plating layer 18, and the third plating layer 19, are divided into a plurality of strip-shaped chip resistors excluding the end surface electrodes 16, the first plating layer 17, the second plating layer 18, and the third plating layer 19. More specifically, in the sixth step, for example, the plurality of integrally formed chip resistors are divided into a plurality of strip-shaped chip resistors by applying stress from rollers (not shown) provided above and below.

[0041] In the seventh step, a plurality of end electrodes 16 are formed on the chip resistors divided into a plurality of strips. More specifically, in the seventh step, for example, an end electrode paste (not shown) made of the mixture is applied to a stainless steel roller (not shown), and then the roller is rotated to form a plurality of end electrodes 16 on each of the plurality of strip-shaped chip resistors. As a result, in each of the plurality of strip-shaped chip resistors, the plurality of upper electrodes 12 and the plurality of lower electrodes 15 are electrically connected via the plurality of end electrodes 16.

[0042] In an eighth step, the rollers are rotated to separate the strip-shaped chip resistors into individual chip resistors.

[0043] In the ninth step, a first plating layer 17 to a third plating layer 19 are formed on each of the plurality of chip resistors. More specifically, in the ninth step, three plating layers, namely, the first plating layer 17, the second plating layer 18, and the third plating layer 19, are formed on each of the plurality of chip resistors in this order.

[0044] The chip resistor 1 according to the first embodiment can be manufactured by the first to ninth steps described above.

[0045] (4) Characteristics of chip resistors Next, the characteristics of the chip resistor 1 using the resistor paste according to embodiment 1 will be described with reference to a comparative example. The volume resistivity of the chip resistor 1 is preferably, for example, 200 μΩ·cm or more. Furthermore, the TCR of the chip resistor 1 is preferably, for example, -50 ppm / °C or more and +50 ppm / °C or less.

[0046] First, in Comparative Example 1, the resistor paste contains metal particles, glass particles, an organic vehicle, and insulating particles. The metal particles contain copper and nickel. The ratio of copper to nickel in the metal particles is 6:4. The insulating particles contain alumina. In Comparative Example 1, as the ratio of insulating particles (alumina) in the resistor paste increases, the resistance value of the resistor made from this resistor paste increases, but the TCR of the resistor becomes too low.

[0047] In Comparative Example 2, the resistor paste contains metal particles, glass particles, an organic vehicle, and a metal silicide. The metal particles contain copper and nickel. The ratio of copper to nickel in the metal particles is 55:45. The metal silicide is titanium silicide. In Comparative Example 2, as the ratio of metal silicide (titanium silicide) in the resistor paste increases, the resistance value of the resistor made from this resistor paste and the TCR of the resistor also increase.

[0048] On the other hand, in embodiment 1, the resistor paste includes metal particles, glass particles, insulating particles, an organic vehicle, and a metal silicide. The metal particles include copper and nickel. The ratio of copper to nickel in the metal particles is 55:45. The insulating particles include alumina, and the metal silicide includes titanium silicide.

[0049] As an example, if the resistor paste contains 70 wt% metal particles, 7 wt% glass particles, 20 wt% insulating particles (alumina), and 3 wt% metal silicide (titanium silicide), the resistance of the resistor 13 made from this resistor paste will be 364 mΩ, and the TCR of the resistor 13 will be -19 ppm. Here, the volume of the resistor 13 is 5.44 × 10 -2 mm 3 Since the resistor 13 has a volume resistivity of -19 ppm when the temperature changes from 25°C to 125°C (length 1.6 mm x width 1.7 mm x thickness 20 μm), the volume resistivity of the resistor 13 made from the resistor paste according to embodiment 1 satisfies the above criteria. Furthermore, the resistor 13 made from the resistor paste according to embodiment 1 has a TCR of -19 ppm when the temperature changes from 25°C to 125°C, so the TCR satisfies the above criteria. In other words, when the resistor 13 is formed from the resistor paste according to embodiment 1, it is possible to lower the TCR of the resistor 13 while increasing the resistance value of the resistor 13. In other words, the resistor paste according to embodiment 1 makes it possible to achieve both high resistivity and low TCR for the resistor 13.

[0050] (5) Effects As described above, the resistor paste according to embodiment 1 contains insulating particles. Therefore, when the resistor 13 of the chip resistor 1 is formed using the resistor paste according to embodiment 1, it is possible to increase the resistivity of the resistor 13. Furthermore, as described above, the resistor paste according to embodiment 1 further contains a metal silicide (e.g., titanium silicide). Therefore, when the resistor 13 of the chip resistor 1 is formed using the resistor paste according to embodiment 1, it is possible to prevent the TCR of the resistor 13 from becoming too low due to an increase in the amount of insulating particles added. In other words, the resistor paste according to embodiment 1 makes it possible to achieve both high resistivity and low TCR for the resistor 13.

[0051] (6) Variations The first embodiment is merely one of various embodiments of the present disclosure. Various modifications of the first embodiment are possible depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the first embodiment are listed below. The modifications described below can be applied in appropriate combinations.

[0052] In the first embodiment, the resistor paste contains titanium silicide as the metal silicide. However, the resistor paste may contain a metal silicide other than titanium silicide. The resistor paste may contain, for example, zirconium silicide, hafnium silicide, niobium silicide, tantalum silicide, chromium silicide, tungsten silicide, molybdenum silicide, iron silicide, magnesium silicide, sodium silicide, or platinum silicide as the metal silicide. The resistor paste may also contain two or more of the above-mentioned materials as the metal silicide. In short, the resistor paste may contain at least one of titanium silicide, zirconium silicide, hafnium silicide, niobium silicide, tantalum silicide, chromium silicide, tungsten silicide, molybdenum silicide, iron silicide, magnesium silicide, sodium silicide, and platinum silicide as the metal silicide.

[0053] In the first embodiment, the resistor paste contains alumina as insulating particles, but the resistor paste may contain insulating particles other than alumina. The resistor paste may contain zirconia, zinc oxide, or boron nitride as insulating particles. The resistor paste may also contain two or more of the above materials as insulating particles. In short, the resistor paste may contain at least one of alumina, zirconia, zinc oxide, and boron nitride as insulating particles.

[0054] In the first embodiment, each end surface electrode 16 has a U-shape when viewed in a direction orthogonal to both the first direction D1 and the second direction D2 (a direction perpendicular to the plane of the paper in FIG. 1 ). However, the shape of each end surface electrode 16 is not limited to a U-shape and may be, for example, an I-shape along the first direction D1. In this case, it is sufficient that a first end (upper end) of the end surface electrode 16 in the first direction D1 contacts a side surface of the top surface electrode 12, and a second end (lower end) of the end surface electrode 16 in the first direction D1 contacts a side surface of the bottom surface electrode 15. This makes it possible to electrically connect the multiple top surface electrodes 12 and the multiple bottom surface electrodes 15 via the multiple end surface electrodes 16.

[0055] (Embodiment 2) A description will be given of the resistor paste, chip resistor 1, and glass particles according to embodiment 2. Regarding the chip resistor 1 according to embodiment 2, the same components as those of the chip resistor 1 according to embodiment 1 will be assigned the same reference numerals and descriptions thereof will be omitted.

[0056] The resistor paste according to the second embodiment differs from the resistor paste according to the first embodiment in that the composition of the glass particles is different.

[0057] (1) Resistor paste composition The resistor paste according to the second embodiment contains metal particles (metal conductors), insulating particles (insulators), metal silicide, and glass particles (glass). That is, the glass particles are used in the resistor paste. The resistor paste according to the second embodiment further contains an organic vehicle.

[0058] The metal particles include copper and nickel. In the second embodiment, the metal particles include, for example, a copper-nickel alloy. The metal particles form conductive paths in the resistor 13 (see FIG. 1) after firing. The metal particles may further include other metals as long as they include copper and nickel.

[0059] The insulating particles include at least one of alumina, zirconia, zinc oxide, and boron nitride. In the second embodiment, the insulating particles include, for example, alumina. The insulating particles reduce the content of metal particles in the fired resistor 13 (see FIG. 1 ) to increase the resistance value, while suppressing the melting and flow of glass particles (described later) to prevent disconnection of the conductive path.

[0060] Metal silicides include, for example, titanium silicide.

[0061] The glass particles contain boron oxide (BO) as a main component, silicon oxide (SiO), aluminum oxide (AlO), tantalum oxide (TaO), and at least one of magnesium oxide (MgO), calcium oxide (CaO), and barium oxide (BaO) as minor components. In embodiment 2, the glass particles contain all of magnesium oxide, calcium oxide, and barium oxide.

[0062] During the firing process of the resistor paste, the glass particles react with copper, nickel, and metal silicide (titanium silicide) to form nickel silicide (Ni 31 Si 12 ) and nickel aluminum boride (Ni 20 These nickel silicides and nickel aluminum borides function to adjust the temperature coefficient of resistance (TCR) of the resistor 13, which will be described later. In the second embodiment, glass particles B, which will be described later, correspond to the glass particles described above.

[0063] The resistor paste may further contain glass particles primarily composed of lead oxide (PbO), such as glass particles A described below, in order to improve the adhesion between the substrate 11 and resistor 13 described below and to melt and solidify the entire resistor 13 to form a strong resistor 13. However, in order not to inhibit the formation of nickel silicide and nickel aluminum boride, it is preferable that the ratio of lead oxide contained in the glass particles (glass particles A) alone is 80 wt% or less, and the total ratio of lead oxide contained in glass particles A and lead oxide contained in glass particles B is 45 wt% or less. For example, glass particles A contain lead oxide as the primary component and boron oxide, silicon oxide, and zinc oxide as secondary components. Furthermore, since the glass particles are insulators, they also have the function of adjusting the resistance value.

[0064] In the resistor paste according to the second embodiment, as described above, the glass particles (glass particles B) contain at least boron oxide and aluminum oxide. In the resistor paste according to the second embodiment, the glass particles (glass particles B) further contain silicon oxide, tantalum oxide, magnesium oxide, calcium oxide, and barium oxide.

[0065] The organic vehicle contains, for example, at least one of an organic binder and an organic solvent. In the resistor paste according to the second embodiment, the organic vehicle contains both an organic binder and an organic solvent. Examples of the organic binder include cellulose-based resins and acrylic-based resins. Examples of the organic solvent include terpineol and butyl carbitol acetate. The mass ratio of the organic vehicle, relative to the metal particles being 100, is preferably, for example, 5 to 200, more preferably 10 to 150, and even more preferably 20 to 100.

[0066] (2) Chip resistor configuration Next, the configuration of the chip resistor 1 according to the second embodiment will be described with reference to FIG.

[0067] 1, the chip resistor 1 according to the second embodiment includes a substrate 11, a plurality of (two in the illustrated example) upper surface electrodes 12, a resistor 13, a protective film 14, a plurality of (two in the illustrated example) lower surface electrodes 15, and a plurality of (two in the illustrated example) end surface electrodes 16. The chip resistor 1 according to the second embodiment further includes a plurality of (two in the illustrated example) first plating layers 17, a plurality of (two in the illustrated example) second plating layers 18, and a plurality of (two in the illustrated example) third plating layers 18. In short, the chip resistor 1 according to the second embodiment includes a substrate 11 and a resistor 13 formed on the substrate 11 using the resistor paste described above as a material.

[0068] The resistor 13 includes a nickel compound. The nickel compound includes, for example, nickel silicide. The nickel silicide is, for example, nickel silicide (Ni 31 Si 12 The nickel compound further includes nickel aluminum boride. Nickel aluminum boride is, for example, nickel aluminum boride (Ni 20 In other words, when the resistor 13 of the chip resistor 1 is formed using the resistor paste described above, nickel compounds including nickel silicide are produced.

[0069] (3) Manufacturing method of chip resistors Next, a method for manufacturing the chip resistor 1 according to the second embodiment will be described.

[0070] The method for manufacturing the chip resistor 1 according to the second embodiment includes the first to eighth steps.

[0071] In the first step, the substrate 11 is prepared. More specifically, in the first step, a substrate body that will be the basis for each of the substrates 11 of the multiple chip resistors 1 is prepared. The substrate body is, for example, a ceramic substrate. The material of the ceramic substrate that will be the substrate body is, for example, an alumina sintered body with an alumina content of 96% or more.

[0072] In the second step, a plurality of upper surface electrodes 12 are formed on the first main surface of the substrate body. The first main surface of the substrate body is a surface that becomes the first main surface 111 of each of the substrates 11 of the plurality of chip resistors 1. More specifically, in the second step, a Cu-based alloy film is formed on the first main surface of the substrate body by, for example, printing a thick film material and then firing it, thereby forming the plurality of upper surface electrodes 12 on each of the plurality of chip resistors 1.

[0073] In the third step, the resistor 13 of each of the plurality of chip resistors 1 is formed. More specifically, in the third step, a resistor paste is printed on the first main surface of the substrate body, and then the resistor 13 is formed by firing. At this time, in the resistor 13, a metal silicide (titanium silicide) reacts with metal particles (copper and nickel) via the glass particles, and a metal silicide different from the metal silicide (titanium silicide), specifically nickel silicide (Ni 31 Si 12 ) is generated. At this time, the titanium from the titanium silicide contained in the resistor paste is taken up by the glass particles, and the silicon from the titanium silicide reacts with the metal particles (copper and nickel), causing the titanium silicide contained in the resistor paste to almost disappear. Furthermore, the metal particles (copper and nickel) react directly with the glass particles to form metal borides, specifically nickel aluminum boride (Ni 20 Al3B6) is also produced. In this way, in the chip resistor 1 according to the second embodiment, the resistor element 13 contains at least nickel silicide (nickel silicide).

[0074] In the fourth step, a protective film 14 is formed on each of the plurality of chip resistors 1. More specifically, in the fourth step, an epoxy resin is applied so as to cover the entire resistor 13, and then the epoxy resin is thermally cured to form the protective film 14. As shown in FIG. 1, the protective film 14 also covers the contact portions between the plurality of upper surface electrodes 12 and the resistor 13.

[0075] In the fifth step, a plurality of lower electrodes 15 for each of the plurality of chip resistors 1 are formed on the second main surface of the substrate body. More specifically, in the second step, a Cu-based alloy film is formed on the second main surface of the substrate body by, for example, printing a thick film material and then firing it, thereby forming a plurality of lower electrodes 15 for each of the plurality of chip resistors 1. The second main surface of the substrate body is the surface that becomes the second main surface 112 of the substrate 11 of each of the plurality of chip resistors 1.

[0076] In the sixth step, the plurality of chip resistors 1 integrally formed by the first to fifth steps are cut into individual chip resistors 1. More specifically, in the sixth step, the plurality of chip resistors 1 integrally formed are cut into individual chip resistors 1 using, for example, a laser or dicing.

[0077] In the seventh step, a plurality of end electrodes 16 are formed on the individually cut chip resistors 1. More specifically, in the seventh step, for example, an end electrode paste (not shown) made of the above mixture is formed on a stainless steel roller (not shown), and then the roller is rotated to form a plurality of end electrodes 16 on each of the plurality of chip resistors 1. As a result, in each of the plurality of chip resistors 1, the plurality of upper electrodes 12 and the plurality of lower electrodes 15 are electrically connected via the plurality of end electrodes 16.

[0078] In the eighth step, a first plating layer 17 to a third plating layer 19 are formed on each of the plurality of chip resistors 1. More specifically, in the eighth step, three plating layers, the first plating layer 17, the second plating layer 18, and the third plating layer 19, are formed on each of the plurality of chip resistors 1 in this order.

[0079] The chip resistor 1 according to the second embodiment can be manufactured through the first to eighth steps described above.

[0080] In the above-described method for manufacturing the chip resistor 1, the fifth step may be performed, for example, before the second step.

[0081] (4) Characteristics of chip resistors Next, the characteristics of the chip resistor 1 using the above-mentioned resistor paste will be described with reference to FIG. 2 and Tables 1 to 3. The horizontal axis of FIG. 2 shows the ratio of glass particles B to the total of glass particles A and B, and the vertical axis of FIG. 2 shows the TCR of the resistor 13. Table 1 shows the composition ratio of glass particles A. Table 2 shows the composition ratio of glass particles B. Table 3 shows the relationship between the compounded composition of the resistor paste and the electrical characteristics and reference intensity ratio (RIR) of the resistor of the chip resistor using the resistor paste.

[0082] [Table 1]

[0083] [Table 2]

[0084] [Table 3] (unit: wt%)

[0085] As shown in Table 1, glass particles A contain lead oxide (PbO), boron oxide (BO), zinc oxide (ZnO), and silicon oxide (SiO). In glass particles A, the ratio of lead oxide is 60 wt% or more and 80 wt% or less, the ratio of boron oxide is 15 wt% or more and 20 wt% or less, the ratio of zinc oxide is 1 wt% or more and 5 wt% or less, and the ratio of silicon oxide is 5 wt% or more and 15 wt% or less. In embodiment 2, as an example, the ratio of lead oxide is 71 wt% or less, the ratio of boron oxide is 16 wt%, the ratio of zinc oxide is 5 wt%, and the ratio of silicon oxide is 8 wt%.

[0086] Glass particles B contain silicon oxide, aluminum oxide, boron oxide, calcium oxide (CaO), magnesium oxide (MgO), barium oxide (BaO), and tantalum oxide (Ta2O5), as shown in Table 2. In glass particles B, the silicon oxide content is 2 wt% or more and 7 wt% or less, the aluminum oxide content is 4 wt% or more and 9 wt% or less, and the boron oxide content is 41 wt% or more and 50 wt% or less. In addition, in glass particles B, the calcium oxide content is 1 wt% or more and 5 wt% or less, the magnesium oxide content is 1 wt% or more and 5 wt% or less, the barium oxide content is 30 wt% or more and 35 wt% or less, and the tantalum oxide content is 3 wt% or more and 10 wt% or less. In the second embodiment, for example, the silicon oxide ratio is 4 wt%, the aluminum oxide ratio is 6 wt%, the boron oxide ratio is 46 wt%, the calcium oxide ratio is 3 wt%, the magnesium oxide ratio is 3 wt%, the barium oxide ratio is 33 wt%, and the tantalum oxide ratio is 5 wt%.

[0087] In Comparative Example 1, the resistor paste contains copper-nickel alloy (CuNi), titanium silicide (TiSi2), aluminum oxide, and glass particles A, as shown in Table 3. In Comparative Example 1, the copper-nickel alloy reacts with titanium silicide via glass particles A to form nickel silicide (Ni 31 Si 12 ) is generated. In addition to nickel silicide, in Comparative Example 1, copper-nickel alloy, titanium silicide, and aluminum oxide are also contained in the resistor 13. That is, in Comparative Example 1, as shown in Table 3, nickel silicide, copper-nickel alloy, titanium silicide, and aluminum oxide are contained in the resistor 13. In Comparative Example 1, the TCR is -126.8 ppm due to nickel silicide, but is smaller than -50 ppm (see point P1 in Figure 2). In Comparative Example 1, the average resistance value of the chip resistor is 300 mΩ. That is, in Comparative Example 1, the TCR is smaller than -50 ppm and is not included in the range of -50 ppm or more and +50 ppm or less (hereinafter referred to as the "predetermined range").

[0088] In Example 1, the resistor paste contains copper-nickel alloy (metal particles), titanium silicide (metal silicide), aluminum oxide (insulating particles), glass particles A, and glass particles B (glass particles), as shown in Table 3. That is, in Example 1, the resistor paste further contains glass particles B. In Comparative Example 1, the ratio of glass particles A in the resistor paste is 7.76 wt%, whereas in Example 1, the ratio of glass particles A in the resistor paste is 3.88 wt%, and the ratio of glass particles B in the resistor paste is 3.88 wt%. In Example 1, the resistor paste contains glass particles B, which are mainly composed of highly reactive boron oxide, and this promotes the reaction of titanium silicide to form nickel silicide (Ni 31 Si 12 ) is generated, the amount of generated metal increases. As a result, in Example 1, the TCR of the resistor 13 becomes −38.0 ppm, which falls within the above-mentioned predetermined range (see point P2 in FIG. 2). In Example 1, the average resistance value of the chip resistor 1 becomes 350 mΩ, as shown in Table 3. In Example 1, the resistor 13 contains copper-nickel alloy, aluminum oxide, and nickel silicide, as shown in Table 3.

[0089] In Example 2, the resistor paste contains copper-nickel alloy (metal particles), titanium silicide (metal silicide), aluminum oxide (insulating particles), glass particles A, and glass particles B (glass particles), as shown in Table 3. In Example 2, the ratio of glass particles A and B in the resistor paste is changed compared to Example 1. Specifically, in Example 2, the ratio of glass particles A in the resistor paste is 2.16 wt %, and the ratio of glass particles B in the resistor paste is 5.60 wt %. As a result, in Example 2, the TCR of the resistor 13 is −15.1 ppm, which is within the predetermined range (see point P3 in FIG. 2). In Example 2, the average resistance value of the chip resistor 1 is 414 mΩ, as shown in Table 3. In Example 2, the resistor 13 contains copper-nickel alloy, aluminum oxide, and nickel silicide, as shown in Table 3.

[0090] As shown in Table 3, Example 3 contains copper-nickel alloy (metal particles), titanium silicide (metal silicide), aluminum oxide (insulating particles), and glass particles B (glass particles). That is, in Example 3, all of the glass particles A are replaced with glass particles B. In Example 3, the ratio of glass particles B in the resistor paste is 7.76 wt%. In Example 3, by replacing all of the glass particles A with glass particles B, the reaction between the copper-nickel alloy and glass particles B is also activated, and nickel silicide (Ni 31 Si 12 ), as well as nickel aluminum boride (Ni 20 Al3B6) is generated. As a result, in Example 3, the TCR of the resistor 13 is −0.5 ppm, which is within the above-mentioned predetermined range (see point P4 in FIG. 2). In Example 3, the average resistance value of the chip resistor 1 is 363 mΩ. In Example 3, as shown in Table 3, the resistor 13 contains copper-nickel alloy, aluminum oxide, nickel silicide, and nickel-aluminum boride.

[0091] Here, the approximate formula for points P2 to P4 corresponding to the above-mentioned Examples 1 to 3 is formula (1) (see dashed line a1 in FIG. 2). Note that "x" in formula (1) is the ratio of glass particles B to the sum of glass particles A and B, and "y" in formula (1) is TCR. [Number 1] y=-102.52x 2 +228.81x-126.8 (1)

[0092] When both glass particles A and B are contained in the resistor paste as in the above-mentioned Examples 1 and 2, nickel silicide (nickel silicide) is produced when the resistor 13 of the chip resistor 1 is formed. When only glass particles B are contained in the resistor paste as in the above-mentioned Example 3, nickel aluminum boride (nickel aluminum boride) is produced in addition to nickel silicide when the resistor 13 of the chip resistor 1 is formed.

[0093] (Aspect) The present specification discloses the following aspects.

[0094] A resistor paste according to a first aspect includes metal particles, insulating particles, glass particles, and a metal silicide. The metal particles include copper and nickel. The insulating particles include at least one of alumina, zirconia, zinc oxide, and boron nitride.

[0095] According to this embodiment, it is possible to achieve both high specific resistance and low TCR for the resistor (13).

[0096] The resistor paste according to the second aspect is the same as that of the first aspect, and further includes, as the metal silicide, at least one of titanium silicide, zirconium silicide, hafnium silicide, niobium silicide, tantalum silicide, chromium silicide, tungsten silicide, molybdenum silicide, iron silicide, magnesium silicide, sodium silicide, and platinum silicide.

[0097] According to this embodiment, it is possible to suppress a decrease in the TCR of the resistor (13).

[0098] A resistor paste according to a third aspect includes metal particles, insulating particles, metal silicide, and glass particles. The metal particles include copper and nickel. The insulating particles include at least one of alumina, zirconia, zinc oxide, and boron nitride. The glass particles include at least boron oxide and aluminum oxide. When the resistor paste is used to form a resistor (13) of a chip resistor (1), nickel compounds including nickel silicide are generated.

[0099] According to this embodiment, it is possible to achieve both high specific resistance and low TCR for the resistor (13).

[0100] In the resistor paste according to the fourth aspect, in the third aspect, the nickel compound further includes nickel aluminum boride.

[0101] According to this embodiment, the TCR of the resistor (13) can be further reduced.

[0102] In the resistor paste according to the fifth aspect, in the fourth aspect, the nickel silicide is Ni 31 Si 12 and nickel aluminum boride is Ni 20 It is Al3B6.

[0103] According to this embodiment, the TCR of the resistor (13) can be further reduced.

[0104] In a resistor paste according to a sixth aspect, in any one of the third to fifth aspects, the glass particles further contain silicon oxide, tantalum oxide, magnesium oxide, calcium oxide, and barium oxide.

[0105] According to this embodiment, it is possible to improve the reactivity with the metal particles and the metal silicide.

[0106] A resistor paste according to a seventh aspect is the same as that of the sixth aspect, in which the glass has a boron oxide ratio of 41 wt% or more and 50 wt% or less, an aluminum oxide ratio of 4 wt% or more and 9 wt% or less, a silicon oxide ratio of 2 wt% or more and 7 wt% or less, a tantalum oxide ratio of 3 wt% or more and 10 wt% or less, a magnesium oxide ratio of 1 wt% or more and 5 wt% or less, a calcium oxide ratio of 1 wt% or more and 5 wt% or less, and a barium oxide ratio of 30 wt% or more and 35 wt% or less.

[0107] According to this embodiment, it is possible to produce nickel silicide.

[0108] In the resistor paste according to an eighth aspect, in any one of the third to seventh aspects, the metal silicide includes titanium silicide.

[0109] According to this embodiment, it is possible to produce nickel silicide.

[0110] A resistor paste according to a ninth aspect is the resistor paste of any one of the first to eighth aspects, further comprising an organic vehicle.

[0111] According to this embodiment, it is possible to mix and disperse the materials uniformly.

[0112] A chip resistor (1) according to a tenth aspect includes a resistor (13) and a substrate (11). The resistor (13) is made of the resistor paste according to any one of the first to ninth aspects and is formed on the substrate (11).

[0113] According to this embodiment, it is possible to achieve both high specific resistance and low TCR for the resistor (13).

[0114] In the chip resistor (1) according to the eleventh aspect, in the tenth aspect, the resistor (13) includes nickel silicide.

[0115] According to this embodiment, it is possible to suppress a decrease in the TCR of the resistor (13).

[0116] The glass particles according to the twelfth aspect are used in the resistor paste according to any one of the third to ninth aspects.

[0117] According to this embodiment, it is possible to achieve both high specific resistance and low TCR for the resistor (13).

[0118] The configurations according to the second and fourth to ninth aspects are not essential for the resistor paste and can be omitted as appropriate. [Explanation of symbols]

[0119] 1 Chip resistor 11 Circuit Board 13 Resistor

Claims

1. Metal particles including copper and nickel; insulating particles comprising at least one of alumina, zirconia, zinc oxide, and boron nitride; Glass particles; a metal silicide; Resistor paste.

2. The metal silicide includes at least one of titanium silicide, zirconium silicide, hafnium silicide, niobium silicide, tantalum silicide, chromium silicide, tungsten silicide, molybdenum silicide, iron silicide, magnesium silicide, sodium silicide, and platinum silicide; The resistor paste according to claim 1 .

3. Metal particles including copper and nickel; insulating particles comprising at least one of alumina, zirconia, zinc oxide, and boron nitride; a metal silicide; glass particles, the glass particles contain at least boron oxide and aluminum oxide; When forming the resistor of a chip resistor, nickel compounds including nickel silicide are generated. Resistor paste.

4. The nickel compound further includes nickel aluminum boride. The resistor paste according to claim 3.

5. The nickel silicide is Ni ３１ Si １２ and The nickel aluminum boride is Ni ２０ Al ３ B ６ That is, The resistor paste according to claim 4.

6. The glass particles further include silicon oxide, tantalum oxide, magnesium oxide, calcium oxide, and barium oxide. The resistor paste according to any one of claims 3 to 5.

7. In the glass particles, The ratio of the boron oxide is 41 wt % or more and 50 wt % or less, The ratio of the aluminum oxide is 4 wt % or more and 9 wt % or less, The ratio of the silicon oxide is 2 wt % or more and 7 wt % or less, The ratio of the tantalum oxide is 3 wt % or more and 10 wt % or less, The ratio of the magnesium oxide is 1 wt% or more and 5 wt% or less, The ratio of the calcium oxide is 1 wt% or more and 5 wt% or less, The ratio of the barium oxide is 30 wt% or more and 35 wt% or less. The resistor paste according to claim 6.

8. the metal silicide comprises titanium silicide; The resistor paste according to any one of claims 3 to 7.

9. further comprising an organic vehicle; The resistor paste according to any one of claims 1 to 8.

10. A resistor formed on a substrate using the resistor paste according to any one of claims 1 to 9 as a material; the substrate; Chip resistors.

11. the resistor comprises nickel silicide; The chip resistor according to claim 10.

12. The resistor paste according to any one of claims 3 to 9 is used. Glass particles.

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