Resistor

Abstract

This resistor comprises an insulating substrate, a first electrode and a second electrode, a resistor body, and an insulating protective film. The insulating protective film has a coating layer which contains: a cured product of a compound (A) having a siloxane bond; and an inorganic filler (B). The compound (A) contains polysilsesquioxane (A1). The content of the cured product of the compound (A) constitutes more than 50 mass% and no more than 100 mass% of the entire coating layer. The content of the inorganic filler (B) constitutes 0 mass% or more and less than 50 mass% of the entire coating layer.

Description

resistor

[0001] This disclosure relates to resistors used in various electronic devices.

[0002] Patent Document 1 discloses an electronic component comprising a substrate, an element portion formed on the substrate, and an insulating protective film covering the element portion, wherein the element portion has trimming grooves, and the insulating protective film has a coating portion containing a cured polysilsesquioxane, and the coating portion has a surface coating layer covering the surface of the element portion and a filling portion filling the trimming grooves.

[0003] International Publication No. 2024 / 057852

[0004] As described above, even if an electronic component is equipped with an insulating protective film having a coating portion containing a cured polysilsesquioxane, there was a problem in that the resistance value of the element portion of the electronic component would fluctuate.

[0005] A resistor according to one aspect of the present disclosure comprises an insulating substrate, a first electrode and a second electrode disposed on the insulating substrate, a resistor electrically connecting the first electrode and the second electrode, and an insulating protective film covering the resistor. The insulating protective film has a coating layer containing a cured product of a compound (A) having siloxane bonds and an inorganic filler (B). The compound (A) contains polysilsesquioxane (A1). The content of the cured product of compound (A) is more than 50% by mass and 100% by mass or less of the entire coating layer, and the content of the inorganic filler (B) is 0% by mass or more and less than 50% by mass of the entire coating layer.

[0006] A resistor according to another aspect of the present disclosure comprises an insulating substrate, a first electrode and a second electrode disposed on the insulating substrate, a resistor electrically connecting the first electrode and the second electrode, and an insulating protective film covering the resistor. The insulating protective film has a coating layer containing a cured product of a compound (A) having siloxane bonds and an inorganic filler (B). The compound (A) includes polysilsesquioxane (A1). The content of the cured product of compound (A) is more than 50% by mass and 100% by mass or less of the entire coating layer, and the content of the inorganic filler (B) is 0% by mass or more and less than 50% by mass of the entire coating layer. The first electrode comprises a first upper electrode disposed on the insulating substrate. The second electrode comprises a second upper electrode disposed on the insulating substrate at a distance from the first upper electrode. The resistor is disposed from at least a portion of the first upper electrode to at least a portion of the second upper electrode. The insulating substrate, the first upper electrode, and the portion of the resistor that overlaps with the first upper electrode are stacked in this order. The insulating substrate, the second upper electrode, and the portion of the resistor that overlaps with the second upper electrode are stacked in this order.

[0007] According to this disclosure, it is possible to provide a resistor in which fluctuations in the resistance value of the resistor are suppressed.

[0008] Figure 1 is a cross-sectional view showing a resistor according to Embodiment 1. Figure 2 is a cross-sectional view showing a modified example of the resistor according to Embodiment 1. Figure 3 is a cross-sectional view showing a modified example of the resistor according to Embodiment 1. Figure 4 is a cross-sectional view showing a resistor according to Embodiment 2.

[0009] (Embodiment 1) 1. Overview Embodiment 1 of this disclosure will be described with reference to the figures. Figure 1 is a cross-sectional view showing a resistor according to Embodiment 1. Note that Embodiment 1 described below is only a part of the various embodiments of this disclosure. Furthermore, Embodiment 1 described below can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure are achieved. The figures referred to below are schematic diagrams, and the dimensional ratios of the components in the figures do not necessarily reflect the actual dimensional ratios. The arrows indicating direction in the drawings are not intended to define the direction in which the resistor 10 is used, but are merely included to make the explanation easier to understand and do not have any actual meaning. In this disclosure, viewing along the thickness direction (vertical direction) is called a plan view.

[0010] The resistor 10 according to Embodiment 1 comprises an insulating substrate 1, a first electrode 41 and a second electrode 42 arranged on the insulating substrate 1, a resistor 2 electrically connecting the first electrode 41 and the second electrode 42, and an insulating protective film 3 covering the resistor 2. The insulating protective film 3 has a coating layer 31 containing a cured product of a compound (A) having siloxane bonds and an inorganic filler (B). Compound (A) includes polysilsesquioxane (A1). The content of the cured product of compound (A) is more than 50% by mass and 100% by mass or less of the entire coating layer 31, and the content of the inorganic filler (B) is 0% by mass or more and less than 50% by mass of the entire coating layer 31. With this configuration, fluctuations in the resistance value of the resistor 2 are suppressed.

[0011] The reason why the resistor 10 according to Embodiment 1 can exhibit the above effects is precisely presumed to be as follows. The coating layer 31 contains a cured compound (A) containing polysilsesquioxane (A1) and an inorganic filler (B), but the affinity between polysilsesquioxane (A1) and the inorganic filler (B) is not very high. Therefore, moisture and other substances can easily penetrate between the polysilsesquioxane (A1) and the inorganic filler (B). In this case, if the amount of inorganic filler (B) relative to the entire coating layer 31 is excessively large, an excessive amount of moisture will penetrate the insulating protective film 3. When this happens, moisture and other substances that have penetrated the insulating protective film 3 can easily reach the resistor 2, and as a result, electrolytic corrosion is likely to occur in the resistor 2. In Embodiment 1, the amount of inorganic filler (B) relative to the entire coating layer 31 is adjusted to a specific range. In other words, the amount of inorganic filler (B) relative to the entire coating layer 31 is not excessively large. In this case, the amount of moisture penetrating the insulating protective film 3 can be reduced, and consequently, the amount of moisture reaching the resistor 2 can be reduced. As a result, electrolytic corrosion occurring on the resistor 2 can be suppressed. In addition, the cured polysilsesquioxane (A1) has moderately suppressed hygroscopicity. In Embodiment 1, the amount of inorganic filler (B) in the entire coating layer 31 is moderately suppressed, and instead, the amount of cured compound (A) containing polysilsesquioxane (A1) in the entire coating layer 31 is moderately increased. In this case, it becomes more difficult for moisture to penetrate the insulating protective film 3. As a result, the coating layer 31 can efficiently prevent contact between the resistor 2 and moisture, etc. As a result, electrolytic corrosion occurring on the resistor 2 can be suppressed.

[0012] Thus, since the content of inorganic filler (B) in the coating layer 31 is moderately suppressed, and the content of compound (A) containing polysilsesquioxane (A1) is moderately increased, electrolytic corrosion occurring in the resistor 2 is suppressed, and as a result, fluctuations in the resistance value of the resistor 2 are suppressed.

[0013] 2. The resistor 10 in Detailed Embodiment 1 will be described with reference to the drawings.

[0014] 2.1 The specific components of the resistor 10 according to the configuration embodiment 1 will be described.

[0015] (Insulating Substrate) The resistor 10 is a chip resistor and includes an insulating substrate 1. The insulating substrate 1 has a rectangular shape when viewed from above. Therefore, the insulating substrate 1 has two opposing surfaces in the thickness direction. For example, the thickness of the insulating substrate 1 is 100 μm or more and 600 μm or less.

[0016] In Embodiment 1, the insulating substrate 1 is made of alumina (Al ２ O ３ The insulating substrate 1 contains a sintered body and may be a ceramic substrate. In addition, the insulating substrate 1 may contain components other than the alumina sintered body. The content of the alumina sintered body in the insulating substrate 1 is preferably 96% by mass or more, more preferably 99% by mass or more, and even more preferably 100% by mass.

[0017] (First electrode and second electrode) In Embodiment 1, the resistor 10 includes a first electrode 41 and a second electrode 42 arranged on the insulating substrate 1 (see Figure 1).

[0018] For example, each of the first electrode 41 and the second electrode 42 may be composed of one electrode or multiple electrodes. In Embodiment 1, each of the first electrode 41 and the second electrode 42 is composed of multiple electrodes.

[0019] In Embodiment 1, each of the first electrode 41 and the second electrode 42 includes each of the first internal electrode 411 and the second internal electrode 421. Each of the first internal electrode 411 and the second internal electrode 421 is arranged on one surface of the resistor 2. For example, each of the first internal electrode 411 and the second internal electrode 421 is provided on the upper surface of each of the left and right ends of the resistor 2 and is electrically connected to the resistor 2.

[0020] The first internal electrode 411 and the second internal electrode 421 can each be formed from a thin-film conductor obtained by a thin-film process such as sputtering. Therefore, the thin-film conductor used to form the first internal electrode 411 and the second internal electrode 421 contains a Ni-based alloy.

[0021] Furthermore, in Embodiment 1, each of the first electrode 41 and the second electrode 42 includes a first end face electrode 412 and a second end face electrode 422, respectively. Each of the first end face electrode 412 and the second end face electrode 422 is positioned to cover the left-right end face of the insulating substrate 1. Each of the first end face electrode 412 and the second end face electrode 422 is also formed on the lower surface of the left-right end of the insulating substrate 1. In addition, each of the first end face electrode 412 and the second end face electrode 422 is also formed on the upper surface of the first internal electrode 411 and the second internal electrode 421, respectively. Each of the first end face electrode 412 and the second end face electrode 422 is electrically connected to the first internal electrode 411 and the second internal electrode 421, respectively.

[0022] The first end electrode 412 and the second end electrode 422 can each be formed from a thin film conductor obtained by a thin film process such as sputtering. Therefore, the thin film conductors used to form the first end electrode 412 and the second end electrode 422 each contain a Ni-based alloy.

[0023] Furthermore, in Embodiment 1, each of the first electrode 41 and the second electrode 42 includes each of the first intermediate electrode 413 and the second intermediate electrode 423. For example, the first intermediate electrode 413 and the second intermediate electrode 423 can be manufactured by forming a Ni plating so as to cover each of the first end electrode 412 and the second end electrode 422.

[0024] In Embodiment 1, each of the first electrode 41 and the second electrode 42 includes each of the first external electrode 414 and the second external electrode 424. For example, the first external electrode 414 and the second external electrode 424 can be manufactured by forming a Sn plating so as to cover each of the first intermediate electrode 413 and the second intermediate electrode 423.

[0025] In Embodiment 1, the first intermediate electrode 413 and the first external electrode 414 cover a portion of the insulating protective film 3. The second intermediate electrode 423 and the second external electrode 424 cover a portion of the insulating protective film 3. Here, the portion of the insulating protective film 3 refers to the left and right edges of the insulating protective film 3. That is, the first intermediate electrode 413 and the first external electrode 414 cover one (left) edge of the insulating protective film 3, and the second intermediate electrode 423 and the second external electrode 424 cover the other (right) edge of the insulating protective film 3. Furthermore, the first intermediate electrode 413 and the first external electrode 414 cover the boundary between the insulating protective film 3 and the first internal electrode 411. In this case, fluctuations in the resistance value of the resistor 2 are more easily suppressed. The second intermediate electrode 423 and the second external electrode 424 cover the boundary between the insulating protective film 3 and the second internal electrode 421. In this case, fluctuations in the resistance value of the resistor 2 are more easily suppressed.

[0026] (Resistor) The resistor 10 includes a resistor 2. The resistor 2 is electrically connected to the first electrode 41 and the second electrode 42. In Embodiment 1, the resistor 2 is placed on one surface of the insulating substrate 1 that faces each other in the thickness direction. The shape of the resistor 2 in plan view is, for example, a rectangle.

[0027] The resistor 2 is composed of a NiCr-based alloy. For example, the resistor 2 can be formed from a thin-film conductor obtained by a thin-film process such as sputtering. Therefore, in Embodiment 1, the thin-film conductor used to form the resistor 2 contains a NiCr-based alloy. Furthermore, the resistor 2 is formed in the form of a thin film. In Embodiment 1, the thickness of the resistor 2 is, for example, 10 nm to 1000 nm.

[0028] (Insulating protective film) The resistor 10 is equipped with an insulating protective film 3. The insulating protective film 3 covers the resistor 2. In Embodiment 1, the insulating protective film 3 covers a part of the first internal electrode 411, a part of the resistor 2, and a part of the second internal electrode 421. More specifically, the insulating protective film 3 covers the portion of the resistor 2 that does not overlap with at least the first electrode 41 and the second electrode 42. That is, the insulating protective film 3 covers the portion of the resistor 2 that is exposed from at least the first electrode 41 and the second electrode 42.

[0029] As already mentioned, the insulating protective film 3 has a coating layer 31. The thickness of the coating layer 31 is preferably 0.5 μm or more and 30.0 μm or less. In this case, fluctuations in the resistance value of the resistor 2 are more easily suppressed.

[0030] In Embodiment 1, when the resistor 2 is viewed from above, the coating layer 31 covers the portion of the resistor 2 that does not overlap with the first electrode 41 and the second electrode 42. That is, when the resistor 2 is viewed from above, the coating layer 31 covers the portion of the resistor 2 that is exposed from the first electrode 41 and the second electrode 42. In this case, fluctuations in the resistance value of the resistor 2 are more easily suppressed. Note that the coating layer 31 may or may not be in direct contact with the resistor 2. In Embodiment 1, an inorganic protective layer 32 is interposed between the resistor 2 and the coating layer 31.

[0031] The coating layer 31 contains a cured product of compound (A) having siloxane bonds and an inorganic filler (B). For example, the coating layer 31 can be made from a coating composition containing compound (A) having siloxane bonds and an inorganic filler (B). This coating composition may also contain components other than compound (A) and inorganic filler (B) in addition to compound (A) and inorganic filler (B), as long as the effects of Embodiment 1 are not impaired. The different components may include, for example, a solvent.

[0032] The compound (A) having a siloxane bond includes polysilsesquioxane (A1). In Embodiment 1, the weight-average molecular weight (Mw) of polysilsesquioxane (A1) is preferably 500 or more and 10,000 or less. For example, the coating layer 31 is made from a coating composition containing polysilsesquioxane (A1), and if the weight-average molecular weight of polysilsesquioxane (A1) is within the above range, the ease of applying the coating composition may be improved. This makes it easier to produce the coating layer 31.

[0033] Polysilsesquioxane (A1) includes, for example, at least one selected from the group consisting of a polysilsesquioxane represented by formula (1), a polysilsesquioxane represented by formula (2), and a polysilsesquioxane represented by formula (3). In other words, coating layer 31 may include a cured product of polysilsesquioxane (A1) containing at least one selected from the group consisting of a polysilsesquioxane represented by formula (1), a polysilsesquioxane represented by formula (2), and a polysilsesquioxane represented by formula (3).

[0034]

[0035] In formulas (1), (2), and (3), each R is independently H (a hydrogen atom), or an alkyl group such as a methyl group or an ethyl group. In formulas (1), (2), and (3), each n is independently an integer of 5 to 50. It is preferable that n is a value such that the weight average molecular weight of polysilsesquioxane (A1) falls within the range of 500 or more and 10000 or less.

[0036] Further, in Embodiment 1, it is preferable that the terminal groups of polysilsesquioxane (A1) include ethoxy groups. This tends to improve the adhesion between the resistor 2 or the inorganic protective layer 32 and the coating layer 31. The terminal groups of polysilsesquioxane (A1) may include a functional group different from an ethoxy group within a range that does not impair the adhesion between the resistor 2 or the inorganic protective layer 32 and the coating layer 31. Examples of functional groups different from an ethoxy group include a hydroxy group and a methoxy group. From the viewpoint of efficiently improving the adhesion between the resistor 2 or the inorganic protective layer 32 and the coating layer 31, it is preferable that the proportion of ethoxy groups in the terminal groups of polysilsesquioxane (A1) is high. Therefore, all terminal groups of the polysilsesquioxane may be ethoxy groups.

[0037] In Embodiment 1, the polysilsesquioxane (A1) preferably has at least one selected from the group consisting of a phenyl group and a methyl group. In this case, fluctuations in the resistance value of the resistor 2 are more easily suppressed. It should be noted that when the proportion of phenyl groups in the functional groups of a cured product of polysilsesquioxane (A1) increases, the rigidity tends to increase and the cured product tends to become harder. Therefore, it is preferable to adjust the ratio of phenyl groups to methyl groups in the functional groups so that cracks are less likely to occur in the coating layer 31.

[0038] Commercially available products can be used as the polysilsesquioxane (A1). Examples of commercially available products include SR-23 (manufactured by Konishi Chemical Industry Co., Ltd., a polysilsesquioxane having an ethoxy group at the terminal, a phenyl group as a functional group, and a weight average molecular weight of 750), SR-13 (manufactured by Konishi Chemical Industry Co., Ltd., a polysilsesquioxane having an ethoxy group at the terminal, a methyl group and a phenyl group as functional groups, and a weight average molecular weight of 4000), SR-33 (manufactured by Konishi Chemical Industry Co., Ltd., a polysilsesquioxane having an ethoxy group at the terminal, functional groups including a methyl group and a phenyl group, and a weight average molecular weight of 5000), and the like.

[0039] The compound (A) may contain a silicone oligomer (A2) in addition to the polysilsesquioxane (A1). The silicone oligomer (A2) can have a lower elastic modulus than that of the polysilsesquioxane (A1). Therefore, when the compound (A) contains the silicone oligomer (A2), thermal stress generated in the coating layer 31 is easily relaxed. This makes it difficult for the insulating protective film 3 to peel off from the first electrode 41, the resistor 2 or the second electrode 42, or makes it difficult for cracks to occur in the insulating protective film 3.

[0040] For example, the terminal groups of the silicone oligomer (A2) include an alkoxy group. Examples of the alkoxy group include a methoxy group, an ethoxy group, and the like.

[0041] For example, the silicone oligomer (A2) includes, for example, a silicone oligomer represented by formula (4). In other words, the coating layer 31 may contain a cured product of the silicone oligomer (A2) containing the silicone oligomer represented by formula (4).

[0042]

[0043] In formula (4), X is independently H (hydrogen atom) or an alkyl group such as a methyl group or an ethyl group. In formula (4), s is independently an integer between 3 and 50. Preferably, s is an integer between 5 and 40.

[0044] The inorganic filler (B) makes it easier to adjust the coefficient of thermal expansion of the coating layer 31. This allows the coefficient of thermal expansion of the coating layer 31 to be brought closer to that of the resistor 2. As a result, even if heat is applied to the resistor 10, the coating layer 31 is less likely to peel off from the resistor 2.

[0045] The inorganic filler (B) includes, for example, at least one selected from the group consisting of silica filler, alumina filler, talc filler, kaolin filler, mica filler, barium sulfate filler, and calcium carbonate filler.

[0046] The content of the cured compound (A) is more than 50% by mass and 100% by mass or less of the total coating layer 31.

[0047] When compound (A) contains a silicone oligomer (A2) in addition to polysilsesquioxane (A1), the content of polysilsesquioxane (A1) is preferably 90% by mass or more and less than 100% by mass of the total compound (A). Furthermore, the content of silicone oligomer (A2) is preferably more than 0% by mass and 10% by mass or less of the total compound (A). In this case, fluctuations in the resistance value of resistor 2 are particularly suppressed.

[0048] The inorganic filler (B) content is 0% by mass or more and less than 50% by mass relative to the entire coating layer 31.

[0049] In Embodiment 1, the insulating protective film 3 has an inorganic protective layer 32 and a resin layer 33 in addition to the coating layer 31. The inorganic protective layer 32, the coating layer 31, and the resin layer 33 are arranged in this order from closest to furthest from the resistor 2.

[0050] The inorganic protective layer 32 is positioned to cover a portion of the resistor 2. The inorganic protective layer 32 is in direct contact with the resistor 2. Furthermore, the inorganic protective layer 32 is positioned to cover a portion of the first internal electrode 411 and a portion of the second internal electrode 421. In other words, when viewed from above, the inorganic protective layer 32 covers the connection portions between the resistor 2 and each of the first internal electrode 411 and the second internal electrode 421. In this case, fluctuations in the resistance value of the resistor 2 can be further suppressed.

[0051] The inorganic protective layer 32 is composed of a metal oxide. The metal oxide is, for example, magnesium oxide (MgO) or aluminum oxide (Al ２ O ３ ), silicon dioxide (SiO ２ ), nickel oxide (Ni ３ O ４ ) and zirconium oxide (ZrO ２ It contains at least one selected from the group consisting of ) etc.

[0052] The resin layer 33 can protect the resistor 2, the inorganic protective layer 32, and the coating layer 31. For example, the resin layer 33 is arranged to cover the entire coating layer 31, in which case fluctuations in the resistance value of the resistor 2 can be further suppressed.

[0053] The resin layer 33 is made from a resin composition containing a resin component such as epoxy resin. In addition to the resin component, the resin composition may also contain at least one selected from the group consisting of silica particles and silicone rubber particles. In this case, the stress generated in the resin layer 33 due to heat, etc., can be relieved compared to when the resin layer 33 is made from a resin component alone. Furthermore, the thermal expansion and contraction of the resin layer 33 can more easily follow the thermal expansion and contraction of the coating layer 31. As a result, the resin layer 33 becomes less likely to peel off from the coating layer 31.

[0054] In Embodiment 1, the resistor 10 is provided with a back surface protective film 8. More specifically, the resistor 10 has a back surface protective layer 8 on the surface of the insulating substrate 1 opposite to the surface on which the resistor 2 is placed. For example, when the resistor 10 is placed on a mounting substrate via solder, the back surface protective film 8 can alleviate thermal stress generated in the resistor 10 due to temperature changes. This can suppress cracks that occur at the junction between the solder and the resistor 10.

[0055] A portion of the first end electrode 412 is positioned on the side of the insulating substrate 1 opposite to the side on which the resistor 2 is located, via the back protective film 8. A portion of the second end electrode 422 is positioned on the side of the insulating substrate 1 opposite to the side on which the resistor 2 is located, via the back protective film 8. For example, the back protective film 8 is made of a resin composition including epoxy resin. The thickness of the back protective film 8 is not particularly limited, but is smaller than that of the insulating substrate 1, for example, about 30 μm.

[0056] 2.2 Manufacturing Method A brief description will be given of the manufacturing method for the resistor 10 according to Embodiment 1.

[0057] First, a thin film conductor containing a NiCr-based alloy is fabricated on one surface of the insulating substrate 1 by a thin-film process such as sputtering. Then, a resistor 2 is fabricated by removing the unnecessary portion of the thin film conductor using a photolithography process.

[0058] Next, a thin film conductor containing a Ni-based alloy is formed on the resistor 2 by a thin-film process such as sputtering, and then the first internal electrode 411 and the second internal electrode 421 are fabricated by removing the unnecessary portion of the thin film conductor using a photolithography process.

[0059] Next, an inorganic protective layer 32 is fabricated by sputtering a metal oxide to cover the resistor 2, a portion of the first internal electrode 411, and a portion of the second internal electrode 421.

[0060] Next, a coating composition containing a compound (A) having a siloxane bond and an inorganic filler (B), etc., is applied to the inorganic protective layer 32. Then, a coating layer 31 is produced by heating and curing this. The temperature at which the above composition is heated when producing the coating layer 31 is about 150 to 200°C. In addition, if the coating composition contains a solvent, the solvent can be removed by heating the applied coating composition.

[0061] Next, a resin composition containing a resin component such as epoxy resin is applied onto the coating layer 31, and the resin layer 33 can be produced by heating and curing it.

[0062] Then, a resin composition containing a resin component such as epoxy resin is applied to the side of the insulating substrate 1 opposite to the side on which the resistor 2 is placed, and this is heated and cured to produce a back surface protective film 8.

[0063] Next, a thin film conductor containing a Ni-based alloy is formed on a portion of the back surface protective layer 8 by a thin film process such as sputtering, thereby forming the first end face electrode 412 and the second end face electrode 422 that overlap the back surface protective layer 8. When forming this thin film conductor, a metal mask is used to perform the thin film process so that the thin film conductor is formed only in the desired locations on the back surface protective layer 8.

[0064] Then, the first intermediate electrode 413 and the second intermediate electrode 423 are fabricated by applying Ni plating to cover the first end electrode 412 and the second end electrode 422, respectively. Subsequently, the first external electrode 414 and the second external electrode 424 are fabricated by applying Sn plating to cover the first intermediate electrode 413 and the second intermediate electrode 423, respectively.

[0065] The resistor 10 according to Embodiment 1 can be manufactured by following these steps. Note that the above method is merely one example of a method for manufacturing the resistor 10 according to Embodiment 1, and any other method may be used.

[0066] 2.3 Modified Examples Modified examples of resistor 10 will be described. Note that the modified examples are examples of variations in which the configuration of Embodiment 1 is partially changed, added, or deleted. Furthermore, with regard to the modified examples, the description of configurations similar to that of resistor 10 in Embodiment 1 will be omitted.

[0067] Figure 2 is a cross-sectional view showing a modified example of the resistor according to Embodiment 1. As shown in Figure 2, the resistor 10 does not need to have a back surface protective film 8.

[0068] The insulating protective film 3 does not necessarily have to be composed of three layers: a coating layer 31, an inorganic protective layer 32, and a resin layer 33. Figure 3 is a cross-sectional view showing another modified example of the resistor according to Embodiment 1. As shown in Figure 3, the insulating protective film 3 does not necessarily have an inorganic protective layer 32. Even without the inorganic protective layer 32, the insulating protective film 3 can adequately protect the resistor 2. Furthermore, since the inorganic protective layer 32 is not interposed between the coating layer 31 and the resistor 2, the coating layer 31 and the resistor 2 can come into direct contact. However, in this disclosure, the content of the inorganic filler (B) is moderately suppressed to 0% by mass or more and less than 50% by mass of the entire coating layer 31. In this case, the contact points between the inorganic filler (B) contained in the coating layer 31 and the resistor 2 are reduced. Therefore, fluctuations in the resistance value of the resistor 2 are sufficiently suppressed.

[0069] <Examples> The present disclosure will be specifically described below with reference to examples. However, the present disclosure is not limited to the following examples.

[0070] 1. Method for Preparing Evaluation Samples A thin film conductor containing a NiCr-based alloy was fabricated on one surface of an insulating substrate (alumina sintered substrate) by a thin film process. A resistor was then fabricated by removing the unwanted portion of the thin film conductor by a photolithography process. Subsequently, a thin film conductor containing a Ni-based alloy was formed on the resistor by a thin film process, and then the first and second internal electrodes were fabricated by removing the unwanted portion of the thin film conductor by a photolithography process. Next, an inorganic protective layer was fabricated by sputtering a metal oxide to cover the resistor, a portion of the first internal electrode, and a portion of the second internal electrode. Subsequently, a coating composition containing a compound (A) having a siloxane bond and an inorganic filler (B), etc., was applied to the inorganic protective layer. This was then dried at 120°C for 30 minutes, and then heated at 200°C for 1 hour to cure, thereby fabricating a coating layer. Next, a resin composition containing epoxy resin was applied to the coating layer, and this was heated at 200°C for 1 hour to cure, thereby fabricating a resin layer. Evaluation samples were prepared according to this method.

[0071] Six types of evaluation samples were prepared, each with a different inorganic filler content. Fifteen identical evaluation samples were prepared for each type, and these were evaluated.

[0072] The details of the components contained in the coating composition are shown below.

[0073] (Compound containing siloxane bonds) Polysilsesquioxane (SR-13 from Konishi Chemical Industry Co., Ltd.) (Inorganic filler) Silica (D50: 0.4 μm) 2. Evaluation Corrosion resistance tests were conducted on the evaluation samples. First, the initial resistance value of the resistor was measured for the evaluation samples. Next, the evaluation samples were immersed in corrosive oil (containing amines) at a temperature of 85°C for 1000 hours. Then, the resistance value of the resistor of the evaluation samples after immersion in the corrosive oil was measured, and the rate of change in resistance value was confirmed.

[0074] As described in "1. Method for Preparing Evaluation Samples," there were six types of evaluation samples, each with a different inorganic filler content, and 15 identical samples were prepared for each type. The average value of the rate of change in the resistance of the resistors of the 15 evaluation samples for each type was calculated. This average value was then used as the rate of change in the resistance of the resistors of each type of evaluation sample, and is shown in Table 1.

[0075]

[0076] It was shown that if the inorganic filler (B) content in the coating layer is 50% by mass or less, the rate of change in the resistance value becomes low.

[0077] (Aspects) As is clear from Embodiment 1 above, this disclosure includes the following aspects. Hereafter, reference numerals are enclosed in parentheses solely to indicate their correspondence with Embodiment 1.

[0078] A resistor (10) according to a first aspect of the present disclosure comprises an insulating substrate (1), a first electrode (41) and a second electrode (42) disposed on the insulating substrate (1), a resistor (2) electrically connecting the first electrode (41) and the second electrode (42), and an insulating protective film (3) covering the resistor (2). The insulating protective film (3) has a coating layer (31) containing a cured product of a compound (A) having siloxane bonds and an inorganic filler (B). Compound (A) includes polysilsesquioxane (A1). The content of the cured product of compound (A) is more than 50% by mass and 100% by mass or less of the entire coating layer (31). The content of the inorganic filler (B) is 0% by mass or more and less than 50% by mass of the entire coating layer (31).

[0079] According to this embodiment, a resistor (10) can be provided in which fluctuations in the resistance value of the resistor (2) are suppressed.

[0080] In the first embodiment, the resistor (10) according to a second aspect of the present disclosure further comprises a silicone oligomer (A2) as compound (A). The content of polysilsesquioxane (A1) is 90% by mass or more and less than 100% by mass of the total compound (A). The content of silicone oligomer (A2) is more than 0% by mass and 10% by mass or less of the total compound (A).

[0081] In the third aspect of the present disclosure, the resistor (10) has a coating layer (31) with a thickness of 0.5 μm or more and 30.0 μm or less, in the first or second aspect.

[0082] In the fourth aspect of the present disclosure, the resistor (10) comprises an ethoxy group at the end of the polysilsesquioxane (A1) in any one of the first to third aspects.

[0083] A resistor (10) according to a fifth aspect of the present disclosure, in any one of the first to fourth aspects, the polysilsesquioxane (A1) has at least one selected from the group consisting of phenyl groups and methyl groups.

[0084] In the sixth aspect of the present disclosure, the resistor (10), in any one of the first to fifth aspects, when the resistor (2) is viewed from above, the covering layer (31) covers the portion of the resistor (2) that does not overlap with the first electrode (41) and the second electrode (42).

[0085] A resistor (10) according to a seventh aspect of the present disclosure, in any one of the first to sixth aspects, further comprises an inorganic protective layer (32) disposed on the resistor (2) as an insulating protective film (3). The resistor (2), the inorganic protective layer (32), and the coating layer (31) are arranged in this order.

[0086] A resistor (10) according to the eighth aspect of this disclosure, in any one of the first to seventh aspects, further comprises an insulating protective film (3) having a resin layer (33) disposed on the coating layer (31). The resistor (2), the coating layer (31), and the resin layer (33) are arranged in this order.

[0087] (Embodiment 2) 1. Overview Embodiment 2 of the present disclosure will be described with reference to the figures. Figure 4 is a cross-sectional view showing a resistor 10A according to Embodiment 2. Note that Embodiment 2 described below is only a part of the various embodiments of the present disclosure. Furthermore, Embodiment 2 described below can be modified in various ways depending on the design, etc., as long as the objectives of the present disclosure are achieved. The figures referred to below are schematic diagrams, and the dimensional ratios of the components in the figures do not necessarily reflect the actual dimensional ratios. The arrows indicating direction in the drawings are not intended to define the direction in which the resistor 10A is used, but are merely included to make the explanation easier to understand and do not have any actual meaning. In the following description, the thickness direction of the insulating substrate 1 is referred to as the vertical direction, and in the vertical direction, the side on which the resistor 2 is arranged relative to the insulating substrate 1 is referred to as the top, and the opposite side is referred to as the bottom. Also, the direction perpendicular to the vertical direction and in which the first electrode 41 and the second electrode 42 are aligned is referred to as the left-right direction, and in the left-right direction, the side of the second electrode 42 relative to the first electrode 41 is referred to as the left, and the side of the first electrode 41 relative to the second electrode 42 is referred to as the right. Viewing along the thickness direction (vertical direction) is called a planar view.

[0088] The resistor 10A according to Embodiment 2 comprises an insulating substrate 1, a first electrode 41 and a second electrode 42 disposed on the insulating substrate 1, a resistor 2 electrically connecting the first electrode 41 and the second electrode 42, and an insulating protective film 3 covering the resistor 2. The insulating protective film 3 has a coating layer 31 containing a cured product of a compound (A) having siloxane bonds and an inorganic filler (B). Compound (A) includes polysilsesquioxane (A1). The content of the cured product of compound (A) is more than 50% by mass and 100% by mass or less of the entire coating layer 31, and the content of the inorganic filler (B) is 0% by mass or more and less than 50% by mass of the entire coating layer 31. The first electrode 41 comprises a first upper electrode 411 disposed on the insulating substrate 1. The second electrode 42 comprises a second upper electrode 421 disposed on the insulating substrate 1 at a distance from the first upper electrode 411. The resistor 2 is positioned extending from at least a portion of the first upper electrode 411 to at least a portion of the second upper electrode 421. The insulating substrate 1, the first upper electrode 411, and the portion of the resistor 2 that overlaps with the first upper electrode 411 are stacked in this order. The insulating substrate 1, the second upper electrode 421, and the portion of the resistor 2 that overlaps with the second upper electrode 421 are stacked in this order. This configuration suppresses fluctuations in the resistance value of the resistor 2.

[0089] The reason why the resistor 10A according to Embodiment 2 can exhibit the above effects is presumed to be as follows. The coating layer 31 contains a cured compound (A) containing polysilsesquioxane (A1) and an inorganic filler (B), but the affinity between polysilsesquioxane (A1) and the inorganic filler (B) is not very high. Therefore, moisture and other substances can easily penetrate between the polysilsesquioxane (A1) and the inorganic filler (B). In this case, if the amount of inorganic filler (B) relative to the entire coating layer 31 is excessively large, an excessive amount of moisture will penetrate the insulating protective film 3. If this happens, the moisture and other substances that have penetrated the insulating protective film 3 will easily reach the resistor 2, and as a result, electrolytic corrosion is likely to occur in the resistor 2. In Embodiment 2, the amount of inorganic filler (B) relative to the entire coating layer 31 is adjusted to a specific range. In other words, the amount of inorganic filler (B) relative to the entire coating layer 31 is not excessively large. In this case, the amount of moisture penetrating the insulating protective film 3 can be reduced, and consequently, the amount of moisture reaching the resistor 2 can be reduced. As a result, electrolytic corrosion occurring on the resistor 2 can be suppressed. In addition, the cured polysilsesquioxane (A1) has moderately suppressed hygroscopicity. In Embodiment 2, the amount of inorganic filler (B) in the entire coating layer 31 is moderately suppressed, and instead, the amount of cured compound (A) containing polysilsesquioxane (A1) in the entire coating layer 31 is moderately increased. In this case, it becomes more difficult for moisture to penetrate the insulating protective film 3. As a result, the coating layer 31 can efficiently prevent contact between the resistor 2 and moisture, etc. As a result, electrolytic corrosion occurring on the resistor 2 can be suppressed.

[0090] Thus, since the content of inorganic filler (B) in the coating layer 31 is moderately suppressed, and the content of compound (A) containing polysilsesquioxane (A1) is moderately increased, electrolytic corrosion occurring in the resistor 2 is suppressed, and as a result, fluctuations in the resistance value of the resistor 2 are suppressed.

[0091] 2. The resistor 10A in the detailed embodiment 2 will be described with reference to the drawings.

[0092] 2.1 The specific components of the resistor 10A according to the second embodiment of the configuration will be described.

[0093] The resistor 10A includes an insulating substrate 1, a first electrode 41, a second electrode 42, a resistor 2, and an insulating protective film 3.

[0094] Each of the first electrode 41 and the second electrode 42 is spaced apart from each other on the surface of the insulating substrate 1. The resistor 2 is disposed on the insulating substrate 1 at a position between the first electrode 41 and the second electrode 42.

[0095] The resistor 2 is in contact with each of the first electrode 41 and the second electrode 42, and is electrically connected to each of the first electrode 41 and the second electrode 42.

[0096] The insulating protective film 3 covers the resistor 2. For example, the insulating protective film 3 covers the resistor 2 such that the resistor 2 is not exposed to the outside of the resistor 10A.

[0097] (Insulating Substrate) The resistor 10A is a chip resistor and includes the insulating substrate 1. The insulating substrate 1 has a rectangular shape when viewed in plan. Therefore, the insulating substrate 1 has two faces (upper face and lower face) opposed to each other in the thickness direction (vertical direction). For example, the thickness of the insulating substrate 1 is not less than 100 μm and not more than 600 μm.

[0098] In Embodiment 2, the insulating substrate 1 is made of alumina (Al ２ O ３ ) sintered body. Note that the insulating substrate 1 may contain a component different from the alumina sintered body in addition to the alumina sintered body. The content of the alumina sintered body relative to the insulating substrate 1 is preferably 96 mass% or more, more preferably 99 mass% or more, and still more preferably 100 mass%.

[0099] (First Electrode and Second Electrode) In Embodiment 2, the resistor 10A includes the first electrode 41 and the second electrode 42 disposed on the insulating substrate 1 (see FIG. 4).

[0100] The first electrode 41 is disposed at a left end portion of the insulating substrate 1, and the second electrode 42 is disposed at an end portion of the insulating substrate 1 on a side (right side) opposite to the first electrode 41 side.

[0101] In Embodiment 2, each of the first electrode 41 and the second electrode 42 is composed of multiple electrodes. The first electrode 41 includes, for example, a first top electrode (first internal electrode) 411, a first end electrode 412, a first intermediate electrode 413, a first external electrode 414, a first back electrode 415, and a first connecting electrode 416. The second electrode 42 includes, for example, a second top electrode (second internal electrode) 421, a second end electrode 422, a second intermediate electrode 423, a second external electrode 424, a second back electrode 425, and a second connecting electrode 426.

[0102] For example, the first electrode 41 includes a first top electrode (first internal electrode) 411, and the second electrode 42 includes a second top electrode (second internal electrode) 421. The first internal electrode 411 is arranged on the insulating substrate 1. The second electrode 42 is arranged on the insulating substrate 1 at a distance from the first top electrode (first internal electrode) 411.

[0103] Each of the first internal electrode 411 and the second internal electrode 421 is arranged on, for example, one surface (top surface) of the insulating substrate 1. For example, the first internal electrode 411 and the second internal electrode 421 are arranged on the top surface of the left end and the top surface of the right end of the insulating substrate 1, respectively. The first internal electrode 411 and the second internal electrode 421 are spaced apart in the left-right direction.

[0104] For example, the first internal electrode 411 and the second internal electrode 421 are electrically connected to the resistor 2 by contact. The upper surface of the first internal electrode 411 is in contact with the left end of the resistor 2 on the first electrode 41 side. The upper surface of the second internal electrode 421 is in contact with the right end of the resistor 2 on the second electrode 42 side.

[0105] The end of the resistor 2 on the first electrode 41 side (left side) may reach the outer (left side) edge in the left-right direction of the upper surface of the first internal electrode 411, but the end of the resistor 2 may not reach the edge of the first internal electrode 411, and there may be a portion on the upper surface of the first internal electrode 411 where the resistor 2 is not positioned between the end of the resistor 2 and the edge of the first internal electrode 411. That is, in a plan view, there may be a portion between both ends of the upper surface of the first internal electrode 411 where the resistor 2 is not positioned, and there may be a portion between both ends of the upper surface of the first internal electrode 411 where the resistor 2 is exposed. The end of the resistor 2 on the second electrode 42 side (right side) may reach the outer (right side) edge in the left-right direction of the upper surface of the second internal electrode 421, but the end of the resistor 2 may not reach the edge of the second internal electrode 421, and there may be a portion on the upper surface of the second internal electrode 421 where the resistor 2 is not positioned between the end of the resistor 2 and the edge of the second internal electrode 421. In other words, in a plan view, there may be a portion between the two ends of the upper surface of the second internal electrode 421 where the resistor 2 is not positioned, and there may be a portion between the two ends of the upper surface of the second internal electrode 421 that is exposed from the resistor 2.

[0106] Each of the first internal electrode 411 and the second internal electrode 421 can be manufactured by applying a conductive paste containing, for example, Au, to the insulating substrate 1 by printing or other means, and then firing it.

[0107] For example, the first electrode 41 is equipped with a first connecting electrode 416, and the second electrode 42 is equipped with a second connecting electrode 426. The first connecting electrode 416 electrically connects the first end electrode 412 and the first top electrode 411, and the second connecting electrode 426 electrically connects the second end electrode 422 and the second top electrode 421.

[0108] The first connecting electrode 416 is placed on top of the first internal electrode 411 so as to contact the portion of the outer (left) end of the first internal electrode 411 that is not covered by the resistor 2. That is, the first connecting electrode 416 contacts the portion of the upper surface of the first internal electrode 411 that is not covered by the resistor 2. In this way, the first connecting electrode 416 contacts the portion of the upper surface of the first internal electrode 411 that is exposed from the resistor 2. Furthermore, the first connecting electrode 416 may also cover the portion of the resistor 2 that overlaps with the first internal electrode 411. The second connecting electrode 426 is placed on top of the second internal electrode 421 so as to contact the portion of the outer (right) end of the second internal electrode 421 that is not covered by the resistor 2. That is, the second connecting electrode 426 contacts the portion of the upper surface of the second internal electrode 421 that is not covered by the resistor 2. In this way, the second connecting electrode 426 contacts the portion of the upper surface of the second internal electrode 421 that is exposed from the resistor 2. Furthermore, the second connecting electrode 426 may also cover the portion of the resistor 2 that overlaps with the second internal electrode 421.

[0109] Each of the first connecting electrode 416 and the second connecting electrode 426 can be formed from a thin-film conductor obtained by a thin-film process such as sputtering. The thin-film conductor for forming each of the first connecting electrode 416 and the second connecting electrode 426 contains, for example, a Ni-based alloy.

[0110] The first electrode 41 and the second electrode 42 include, for example, the first back electrode 415 and the second back electrode 425, respectively. The first back electrode 415 and the second back electrode 425 are each positioned on the surface of the insulating substrate 1 opposite to the surface on which the first internal electrode 411 and the second internal electrode 421 are positioned. For example, the first back electrode 415 and the second back electrode 425 are positioned on the lower surface of the left end and the lower surface of the right end of the insulating substrate 1, respectively. The first back electrode 415 and the second back electrode 425 are spaced apart in the left-right direction.

[0111] Each of the first back electrode 415 and the second back electrode 425 can be manufactured by coating a conductive material containing, for example, a thermosetting resin material and conductive powder onto an insulating substrate 1 by printing or the like, and curing it by heating. The thermosetting resin material may contain, for example, epoxy resin. The conductive powder may contain, for example, silver powder. In this case, each of the first back electrode 415 and the second back electrode 425 contains, for example, a cured product of the thermosetting resin material and conductive powder dispersed in this cured product.

[0112] For example, the first electrode 41 includes a first end-face electrode 412, and the second electrode 42 includes a second end-face electrode 422. The first end-face electrode 412 covers the end face of the insulating substrate 1 on the side of the first electrode 41 (left side). The second end-face electrode 422 covers the end face of the insulating substrate 1 on the side of the second electrode 42 (right side).

[0113] The lower end of the first end face electrode 412 extends inward (to the right) and contacts the lower surface of the first back surface electrode 415 on the lower side of the insulating substrate 1, thereby electrically connecting to the first back surface electrode 415. The lower end of the second end face electrode 422 extends inward (to the left) and contacts the lower surface of the second back surface electrode 425 on the lower side of the insulating substrate 1, thereby electrically connecting to the second back surface electrode 425.

[0114] The upper end of the first end electrode 412 extends inward (to the right) and is positioned on the upper surface of the insulating substrate 1 to cover the upper surface of the first internal electrode 411. On the upper surface of the first internal electrode 411, a first connecting electrode 416 is interposed between the first end electrode 412 and the first internal electrode 411, and the first end electrode 412 and the first internal electrode 411 are electrically connected via the first connecting electrode 416. The upper end of the second end electrode 422 extends inward (to the left) and is positioned on the upper surface of the insulating substrate 1 to cover the upper surface of the second internal electrode 421. On the upper surface of the second internal electrode 421, a second connecting electrode 426 is interposed between the second end electrode 422 and the second internal electrode 421, and the second end electrode 422 and the second internal electrode 421 are electrically connected via the second connecting electrode 426.

[0115] The first end electrode 412 and the second end electrode 422 can each be formed from a thin film conductor obtained by a thin film process such as sputtering. The thin film conductor for forming the first end electrode 412 and the second end electrode 422 may contain, for example, a Ni-based alloy.

[0116] For example, the first electrode 41 includes a first intermediate electrode 413, and the second electrode 42 includes a second intermediate electrode 423.

[0117] The first intermediate electrode 413 is positioned to cover the left edge of the insulating substrate 1. The first intermediate electrode 413 overlaps the first connecting electrode 416, the first end face electrode 412, and the first back surface electrode 415 so as to be in contact with them. The first intermediate electrode 413 is electrically connected to the first connecting electrode 416, the first end face electrode 412, and the first back surface electrode 415, and is also electrically connected to the first internal electrode 411 via the first end face electrode 412 and the first connecting electrode 416.

[0118] The second intermediate electrode 423 is positioned to cover the right edge of the insulating substrate 1. The second intermediate electrode 423 overlaps the second connecting electrode 426, the second end face electrode 422, and the second back surface electrode 425 so as to be in contact with them. The second intermediate electrode 423 is electrically connected to the second connecting electrode 426, the second end face electrode 422, and the second back surface electrode 425, and is also electrically connected to the second internal electrode 421 via the second end face electrode 422 and the second connecting electrode 426.

[0119] The first intermediate electrode 413 and the second intermediate electrode 423 are each formed from a thin film conductor containing, for example, Ni. For example, the first intermediate electrode 413 and the second intermediate electrode 423 can be manufactured by forming a Ni plating so as to cover the left edge and the right edge of the insulating substrate 1.

[0120] For example, the first electrode 41 is equipped with a first external electrode 414, and the second electrode 42 is equipped with a second external electrode 424.

[0121] The first external electrode 414 is positioned, for example, at the left end of the insulating substrate 1, so as to cover the first intermediate electrode 413. The first external electrode 414 overlaps the first intermediate electrode 413 so as to be in contact with it. The first external electrode 414 is electrically connected to the first intermediate electrode 413. The second external electrode 424 is positioned, for example, at the right end of the insulating substrate 1, so as to cover the second intermediate electrode 423. The second external electrode 424 overlaps the second intermediate electrode 423 so as to be in contact with it. The second external electrode 424 is electrically connected to the second intermediate electrode 423.

[0122] The first external electrode 414 and the second external electrode 424 are each formed from a thin film conductor containing, for example, Sn. For example, the first external electrode 414 and the second external electrode 424 can be fabricated by forming a Sn plating over the first intermediate electrode 413 and the second intermediate electrode 423, respectively.

[0123] The first connecting electrode 416, the first intermediate electrode 413, and the first external electrode 414 may cover a portion of the insulating protective film 3. The second connecting electrode 426, the second intermediate electrode 423, and the second external electrode 424 may also cover a portion of the insulating protective film 3. Here, the portion of the insulating protective film 3 refers to the left and right edges of the insulating protective film 3. That is, the first connecting electrode 416, the first intermediate electrode 413, and the first external electrode 414 may cover one (left) edge of the insulating protective film 3, while the second connecting electrode 426, the second intermediate electrode 423, and the second external electrode 424 may cover the other (right) edge of the insulating protective film 3. In addition, the first intermediate electrode 413 and the first external electrode 414 cover the boundary between the insulating protective film 3 and the first connecting electrode 416. In this case, fluctuations in the resistance value of the resistor 2 are more easily suppressed. The second intermediate electrode 423 and the second external electrode 424 cover the boundary between the insulating protective film 3 and the second connecting electrode 426. In this case, fluctuations in the resistance value of resistor 2 become easier to suppress.

[0124] (Resistor) The resistor 10A includes a resistor 2. The resistor 2 is electrically connected to the first electrode 41 and the second electrode 42. The resistor 2 is arranged on, for example, one of the surfaces (top surface) of the insulating substrate 1 that face each other in the thickness direction. The shape of the resistor 2 in plan view is, for example, a rectangle or other rectangular shape.

[0125] The resistor 2 is positioned from at least a portion of the first upper electrode (first internal electrode) 411 to at least a portion of the second upper electrode (second internal electrode) 421. The insulating substrate 1, the first upper electrode (first internal electrode) 411, and the portion of the resistor 2 that overlaps with the first upper electrode (first internal electrode) 411 are stacked in this order. The insulating substrate 1, the second upper electrode (second internal electrode) 421, and the portion of the resistor 2 that overlaps with the second upper electrode (second internal electrode) 421 are stacked in this order.

[0126] The resistor 2 overlaps the insulating substrate 1, for example, between the first internal electrode 411 and the second internal electrode 421, so as to be in contact with the insulating substrate 1. The left end of the resistor 2 is positioned so as to be in contact with the upper surface of the first internal electrode 411, and the right end of the resistor 2 is positioned so as to be in contact with the upper surface of the second internal electrode 421. That is, for example, the insulating substrate 1, the first internal electrode 411, and one (left) end of the resistor 2 are stacked in this order, and the insulating substrate 1, the second internal electrode 421, and the other (right) end of the resistor are stacked in this order. As described above, the end of the resistor 2 on the first electrode 41 side (left) may reach the outer (left) end in the left-right direction of the upper surface of the first internal electrode 411, but the end of the resistor 2 may not reach the end of the first internal electrode 411, and there may be a portion where the resistor 2 is not positioned between the end of the resistor 2 on the upper surface of the first internal electrode 411 and the end of the first internal electrode 411. In other words, in a plan view, there may be a portion between the two ends of the upper surface of the first internal electrode 411 where the resistor 2 is not positioned, and there may be a portion between the two ends of the upper surface of the first internal electrode 411 where the resistor 2 is exposed. The end of the resistor 2 on the second electrode 42 side (right side) may reach the outer (right side) end in the left-right direction of the upper surface of the second internal electrode 421, but the end of the resistor 2 may not reach the end of the second internal electrode 421, and there may be a portion between the end of the resistor 2 on the upper surface of the second internal electrode 421 and the end of the second internal electrode 421 where the resistor 2 is not positioned. In other words, in a plan view, there may be a portion between the two ends of the upper surface of the second internal electrode 421 where the resistor 2 is not positioned, and there may be a portion between the two ends of the upper surface of the second internal electrode 421 where the resistor 2 is exposed.

[0127] The resistor 2 is composed of, for example, a NiCr-based alloy. For example, the resistor 2 can be formed from a thin-film conductor obtained by a thin-film process such as sputtering. Therefore, in Embodiment 2, the thin-film conductor used to form the resistor 2 contains a NiCr-based alloy. Furthermore, the resistor 2 is formed in the form of a thin film. In Embodiment 2, the thickness of the resistor 2 is, for example, 10 nm to 1000 nm.

[0128] (Insulating protective film) The resistor 10A is equipped with an insulating protective film 3. The insulating protective film 3 covers the resistor 2. The insulating protective film 3 covers, for example, at least a portion of the first internal electrode 411, at least a portion of the resistor 2, and at least a portion of the second internal electrode 421. More specifically, the insulating protective film 3 covers the portion of the resistor 2 that does not overlap with at least the first electrode 41 and the second electrode 42. In other words, the insulating protective film 3 covers the portion of the resistor 2 that is exposed from at least the first electrode 41 and the second electrode 42.

[0129] As already mentioned, the insulating protective film 3 has a coating layer 31. The thickness of the coating layer 31 is preferably 0.5 μm or more and 30.0 μm or less. In this case, fluctuations in the resistance value of the resistor 2 are more easily suppressed.

[0130] In Embodiment 2, when the resistor 2 is viewed from above, the coating layer 31 covers the portion of the resistor 2 that does not overlap with the first electrode 41 and the second electrode 42, that is, the portion located between the first electrode 41 and the second electrode 42. When the resistor 2 is viewed from above, the coating layer 31 covers the portion of the resistor 2 that is exposed from the first electrode 41 and the second electrode 42. In this case, fluctuations in the resistance value of the resistor 2 are more easily suppressed. In this case, the coating layer 31 may or may not be in direct contact with the resistor 2. An inorganic protective layer 32 may be interposed between the resistor 2 and the coating layer 31.

[0131] The coating layer 31 contains a cured product of compound (A) having siloxane bonds and an inorganic filler (B). For example, the coating layer 31 can be made from a coating composition containing compound (A) having siloxane bonds and an inorganic filler (B). This coating composition may also contain components different from compound (A) and inorganic filler (B) in addition to compound (A) and inorganic filler (B), as long as the effects of Embodiment 2 are not impaired. The different components may include, for example, a solvent.

[0132] Compound (A) having a siloxane bond includes polysilsesquioxane (A1). In Embodiment 2, the weight-average molecular weight (Mw) of polysilsesquioxane (A1) is preferably 500 or more and 10,000 or less. For example, the coating layer 31 is made from a coating composition containing polysilsesquioxane (A1), and if the weight-average molecular weight of polysilsesquioxane (A1) is within the above range, the ease of applying the coating composition may be improved. This makes it easier to produce the coating layer 31.

[0133] Polysilsesquioxane (A1) includes, for example, at least one selected from the group consisting of polysilsesquioxane represented by formula (5), polysilsesquioxane represented by formula (6), and polysilsesquioxane represented by formula (7). In other words, the coating layer 31 may include a cured product of polysilsesquioxane (A1) containing at least one selected from the group consisting of polysilsesquioxane represented by formula (5), polysilsesquioxane represented by formula (6), and polysilsesquioxane represented by formula (7).

[0134]

[0135] In formulas (5), (6), and (7), R is independently H (hydrogen atom) or an alkyl group such as a methyl group or an ethyl group. In formulas (5), (6), and (7), n is independently an integer between 5 and 50. Preferably, n is a value such that the weight-average molecular weight of polysilsesquioxane (A1) is in the range of 500 to 10000.

[0136] Furthermore, in Embodiment 2, it is preferable that the terminal groups of polysilsesquioxane (A1) include ethoxy groups. This makes it easier to improve the adhesion between the resistor 2 or inorganic protective layer 32 and the coating layer 31. Within a range that does not impair the adhesion between the resistor 2 or inorganic protective layer 32 and the coating layer 31, the terminal groups of polysilsesquioxane (A1) may include functional groups other than ethoxy groups. Examples of functional groups other than ethoxy groups include hydroxyl groups and methoxy groups. From the viewpoint of efficiently improving the adhesion between the resistor 2 or inorganic protective layer 32 and the coating layer 31, it is preferable that the proportion of ethoxy groups in the terminal groups of polysilsesquioxane (A1) is high. Therefore, all the terminal groups of polysilsesquioxane may be ethoxy groups.

[0137] In Embodiment 2, it is preferable that the polysilsesquioxane (A1) has at least one selected from the group consisting of phenyl groups and methyl groups. In this case, fluctuations in the resistance value of the resistor 2 are more easily suppressed. Note that the cured polysilsesquioxane (A1) tends to become harder and more rigid as the proportion of phenyl groups in the functional groups increases. Therefore, it is preferable to adjust the ratio of phenyl groups to methyl groups in the functional groups so that cracks are less likely to occur in the coating layer 31.

[0138] Polysilsesquioxane (A1) can be a commercially available product. Examples of commercially available products include SR-23 (Konishi Chemical Industry Co., Ltd., a polysilsesquioxane with an ethoxy group at the end and a phenyl group as a functional group, with a weight-average molecular weight of 750), SR-13 (Konishi Chemical Industry Co., Ltd., a polysilsesquioxane with an ethoxy group at the end and methyl and phenyl groups as functional groups, with a weight-average molecular weight of 4000), and SR-33 (Konishi Chemical Industry Co., Ltd., a polysilsesquioxane with an ethoxy group at the end and methyl and phenyl groups as functional groups, with a weight-average molecular weight of 5000).

[0139] Compound (A) may contain a silicone oligomer (A2) in addition to polysilsesquioxane (A1). The silicone oligomer (A2) may have a lower elastic modulus than polysilsesquioxane (A1). Therefore, when compound (A) contains a silicone oligomer (A2), the thermal stress generated in the coating layer 31 is more easily relieved. As a result, the insulating protective film 3 is less likely to peel off from the first electrode 41, the resistor 2, or the second electrode 42, or cracks are less likely to occur in the insulating protective film 3.

[0140] For example, the terminal group of the silicone oligomer (A2) contains an alkoxy group. Examples of alkoxy groups include methoxy groups and ethoxy groups.

[0141] For example, the silicone oligomer (A2) includes, for example, a silicone oligomer represented by formula (8). In other words, the coating layer 31 may include a cured product of the silicone oligomer (A2) containing the silicone oligomer represented by formula (8).

[0142]

[0143] In formula (8), X is independently H (hydrogen atom) or an alkyl group such as a methyl group or an ethyl group. In formula (8), s is independently an integer between 3 and 50. Preferably, s is an integer between 5 and 40.

[0144] The inorganic filler (B) makes it easier to adjust the coefficient of thermal expansion of the coating layer 31. This allows the coefficient of thermal expansion of the coating layer 31 to be brought closer to that of the resistor 2. As a result, even if heat is applied to the resistor 10A, the coating layer 31 is less likely to peel off from the resistor 2.

[0145] The inorganic filler (B) includes, for example, at least one selected from the group consisting of silica filler, alumina filler, talc filler, kaolin filler, mica filler, barium sulfate filler, and calcium carbonate filler.

[0146] The content of the cured compound (A) is more than 50% by mass and 100% by mass or less of the total coating layer 31.

[0147] When compound (A) contains a silicone oligomer (A2) in addition to polysilsesquioxane (A1), the content of polysilsesquioxane (A1) is preferably 90% by mass or more and less than 100% by mass of the total compound (A). Furthermore, the content of silicone oligomer (A2) is preferably more than 0% by mass and 10% by mass or less of the total compound (A). In this case, fluctuations in the resistance value of resistor 2 are particularly suppressed.

[0148] The inorganic filler (B) content is 0% by mass or more and less than 50% by mass relative to the entire coating layer 31.

[0149] The insulating protective film 3 may have at least one selected from the group consisting of an inorganic protective layer 32 and a resin layer 33, in addition to the coating layer 31. For example, the inorganic protective layer 32, the coating layer 31, and the resin layer 33 are arranged in this order from closest to the resistor 2. That is, for example, the resistor 2, the inorganic protective layer 32, the coating layer 31, and the resin layer 33 are laminated in this order.

[0150] The inorganic protective layer 32 is positioned to cover at least a portion of the resistor 2. The inorganic protective layer 32 may also be positioned to cover the entire resistor 2. The inorganic protective layer 32 is in direct contact with the resistor 2.

[0151] Furthermore, the inorganic protective layer 32 may be positioned to cover a portion of the first internal electrode 411. The inorganic protective layer 32 may also be positioned to cover a portion of the second internal electrode 421. In other words, when viewed from above, the inorganic protective layer 32 may cover the connection portions between the resistor 2 and each of the first internal electrode 411 and the second internal electrode 421. In this case, fluctuations in the resistance value of the resistor 2 can be further suppressed.

[0152] The inorganic protective layer 32 is composed of, for example, a metal oxide. The metal oxide is, for example, magnesium oxide (MgO) or aluminum oxide (Al ２ O ３ ), silicon dioxide (SiO ２ ), nickel oxide (Ni ３ O ４ ) and zirconium oxide (ZrO ２ It contains at least one selected from the group consisting of ) etc.

[0153] The resin layer 33 can protect the resistor 2, the inorganic protective layer 32, and the coating layer 31. For example, the resin layer 33 is arranged to cover the entire coating layer 31, in which case fluctuations in the resistance value of the resistor 2 can be further suppressed.

[0154] The resin layer 33 is made from a resin composition containing a resin component such as epoxy resin. In addition to the resin component, the resin composition may also contain at least one selected from the group consisting of silica particles and silicone rubber particles. In this case, the stress generated in the resin layer 33 due to heat, etc., can be relieved compared to when the resin layer 33 is made from a resin component alone. Furthermore, the thermal expansion and contraction of the resin layer 33 can more easily follow the thermal expansion and contraction of the coating layer 31. As a result, the resin layer 33 becomes less likely to peel off from the coating layer 31.

[0155] For example, the first connecting electrode 416 is in contact with the end of the insulating protective film 3 on the first electrode 41 side (left side), and the second connecting electrode 426 is in contact with the end of the insulating protective film 3 on the second electrode 42 side (right side). The inner end (right side) of the first connecting electrode 416 is in contact with, for example, the end of the coating layer 31 on the first electrode 41 side (left side). The inner end (left side) of the second connecting electrode 426 is in contact with, for example, the end of the coating layer 31 on the second electrode 42 side (right side). This further suppresses the intrusion of moisture into the resistor 2, and effectively suppresses fluctuations in the resistance value of the resistor 2.

[0156] Furthermore, for example, the first intermediate electrode 413 is in contact with the left side (side) of the insulating protective film 3 on the first electrode 41 side, and the second intermediate electrode 423 is in contact with the right side (side) of the insulating protective film 3 on the second electrode 42 side. For example, the inner (right) end of the first intermediate electrode 413 in the upper part of the insulating substrate 1 is in contact with the left side (side) of the coating layer 31 on the first electrode 41 side. For example, the inner (left) end of the second intermediate electrode 423 in the upper part of the insulating substrate 1 is in contact with the right side (side) of the coating layer 31 on the second electrode 42 side. This further suppresses the intrusion of moisture into the resistor 2, and effectively suppresses fluctuations in the resistance value of the resistor 2.

[0157] Furthermore, for example, the first external electrode 414 is in contact with the end of the insulating protective film 3 on the first electrode 41 side (left side), and the second external electrode 424 is in contact with the end of the insulating protective film 3 on the second electrode 42 side (right side). For example, the inner (right side) end of the first external electrode 414 in the left-right direction is in contact with the end of the coating layer 31 on the first electrode 41 side (left side). For example, the inner (left side) end of the second external electrode 424 in the left-right direction is in contact with the end of the coating layer 31 on the second electrode 42 side (left side). This further suppresses the intrusion of moisture into the resistor 2, and effectively suppresses fluctuations in the resistance value of the resistor 2.

[0158] The left-right position of the first electrode 41 side (left side) of the coating layer 31 is, for example, the position from the inner (right) end to the outer (left) end of the first internal electrode 411 in the left-right direction. That is, the left-right end of the coating layer 31 on the first electrode 41 side is not located inside the inner (right) end of the first internal electrode 411 in the left-right direction, and does not extend beyond the outer (left) end to reach the outer end face of the first internal electrode 411. If the left-right end of the coating layer 31 on the first electrode 41 side is not located inside the inner end of the first internal electrode 411 in the left-right direction, the coating layer 31 can effectively suppress fluctuations in the resistance value of the resistor 2. If the left-right end of the coating layer 31 on the first electrode 41 side does not reach the outer end face of the first internal electrode 411, the coating layer 31 can be prevented from hindering the electrical connection between the first end face electrode 412 and the first internal electrode 411. If the end of the coating layer 31 on the second electrode 42 side (right side) is not located inside the inner end of the second internal electrode 421 in the left-right direction, the coating layer 31 can effectively suppress fluctuations in the resistance value of the resistor 2. If the end of the coating layer 31 on the second electrode 42 side (right side) does not reach the outer end face of the second internal electrode 421, the coating layer 31 can suppress interference with the electrical connection between the second end face electrode 422 and the second internal electrode 421.

[0159] The left-right position of the resin layer 33's first electrode 41 side (left side) is, for example, the position from the inner (right) end to the outer (left) end of the first internal electrode 411 in the left-right direction. That is, the left-right end of the resin layer 33's first electrode 41 side (left side) is not located inside the inner (right) end of the first internal electrode 411 in the left-right direction, and does not extend beyond the outer (left) end to reach the outer end face of the first internal electrode 411. If the left-right end of the resin layer 33's first electrode 41 side (left side) is not located inside the inner end of the first internal electrode 411 in the left-right direction, the resin layer 33 can effectively suppress fluctuations in the resistance value of the resistor 2. If the left-right end of the resin layer 33's first electrode 41 side (left side) does not reach the outer end face of the first internal electrode 411, the resin layer 33 can be prevented from hindering the electrical connection between the first end face electrode 412 and the first internal electrode 411. If the end of the resin layer 33 on the second electrode 42 side (right side) is not located inside the inner end of the second internal electrode 421 in the left-right direction, the resin layer 33 can effectively suppress fluctuations in the resistance value of the resistor 2. If the end of the resin layer 33 on the second electrode 42 side (right side) does not reach the outer end face of the second internal electrode 421, the resin layer 33 can suppress interference with the electrical connection between the second end face electrode 422 and the second internal electrode 421.

[0160] 2.2 Manufacturing Method A brief explanation will be given of the manufacturing method for the resistor 10A according to Embodiment 2.

[0161] First, a conductive material containing a thermosetting resin material and conductive powder is applied to the upper surface of each of the left and right ends of the insulating substrate 1 by printing or the like, and then cured by heating. This creates the first internal electrode 411 and the second internal electrode 421.

[0162] Next, a thin-film conductor containing a NiCr-based alloy is fabricated on one surface (top surface) of the insulating substrate 1 by a thin-film process such as sputtering, so as to cover the first internal electrode 411 and the second internal electrode 421. This fabricates the resistor 2.

[0163] Next, the unwanted portion of resistor 2 is removed using a photolithography process.

[0164] Next, an inorganic protective layer 32 is fabricated by sputtering a metal oxide to cover the resistor 2. When forming this inorganic protective layer 32, sputtering is performed using a metal mask so that the inorganic protective layer 32 is formed only in the desired locations, for example, only on the entire upper surface of the resistor 2.

[0165] Next, a coating composition containing a compound (A) having a siloxane bond and an inorganic filler (B), etc., is applied to the inorganic protective layer 32. Then, a coating layer 31 is produced by heating and curing this. The temperature at which the composition is heated when producing the coating layer 31 is about 150 to 200°C. In addition, if the coating composition contains a solvent, the solvent can be removed by heating the applied coating composition.

[0166] Next, a resin composition containing a resin component such as epoxy resin is applied onto the coating layer 31, and the resin layer 33 can be produced by heating and curing it.

[0167] Next, a conductive material containing a thermosetting resin material and conductive powder is applied to the lower surface of each of the left and right edges of the insulating substrate 1 by printing or the like, and then cured by heating. This creates the first back electrode 415 and the second back electrode 425.

[0168] Next, the first connecting electrode 416 and the second connecting electrode 426 are fabricated by forming a thin film conductor using a thin film process such as sputtering. When forming this thin film conductor, a metal mask is used in the thin film process to ensure that the thin film conductor is formed only in the desired locations.

[0169] Next, the first end face electrode 412 and the second end face electrode 422 are fabricated by forming a thin film conductor using a thin film process such as sputtering. When forming this thin film conductor, a metal mask is used in the thin film process to ensure that the thin film conductor is formed only in the desired locations.

[0170] Then, the first intermediate electrode 413 and the second intermediate electrode 423 are fabricated by applying Ni plating. Subsequently, the first external electrode 414 and the second external electrode 424 are fabricated by applying Sn plating so as to cover the first intermediate electrode 413 and the second intermediate electrode 423.

[0171] The resistor 10A according to Embodiment 2 can be manufactured by following these steps. Note that the above method is merely one example of a method for manufacturing the resistor 10A according to Embodiment 2, and any other method may be used.

[0172] 2.3 Modified Examples Modified examples of resistor 10A will be described. Note that the modified examples are examples of variations in which the configuration of Embodiment 2 is partially changed, added, or deleted. Furthermore, regarding the modified examples, the description of configurations similar to that of resistor 10A in Embodiment 2 will be omitted.

[0173] The insulating protective film 3 does not necessarily have to be composed of three layers: a coating layer 31, an inorganic protective layer 32, and a resin layer 33. For example, the insulating protective film 3 does not have to have an inorganic protective layer 32. If the inorganic protective layer 32 is not interposed between the coating layer 31 and the resistor 2, the coating layer 31 and the resistor 2 may come into direct contact. However, in this disclosure, the content of the inorganic filler (B) is moderately suppressed to 0% by mass or more and less than 50% by mass of the entire coating layer 31. In this case, the contact points between the inorganic filler (B) contained in the coating layer 31 and the resistor 2 are reduced. Therefore, fluctuations in the resistance value of the resistor 2 are sufficiently suppressed.

[0174] (Aspects) As is clear from Embodiment 2 above, this disclosure includes the following aspects. Hereafter, reference numerals are enclosed in parentheses solely to indicate their correspondence with Embodiment 2.

[0175] A resistor (10A) according to the ninth aspect of this disclosure comprises an insulating substrate (1), a first electrode (41) and a second electrode (42) disposed on the insulating substrate (1), a resistor (2) electrically connecting the first electrode (41) and the second electrode (42), and an insulating protective film (3) covering the resistor (2). The insulating protective film (3) has a coating layer (31) containing a cured product of a compound (A) having siloxane bonds and an inorganic filler (B). Compound (A) includes polysilsesquioxane (A1). The content of the cured product of compound (A) is more than 50% by mass and 100% by mass or less of the entire coating layer (31). The content of the inorganic filler (B) is 0% by mass or more and less than 50% by mass of the entire coating layer (31). The first electrode (41) comprises a first upper electrode (411) disposed on the insulating substrate (1). The second electrode (42) includes a second upper electrode (421) which is positioned on the insulating substrate (1) at a distance from the first upper electrode (411). The resistor (2) is positioned from at least a portion of the first upper electrode (411) to at least a portion of the second upper electrode (421). The insulating substrate (1), the first upper electrode (411), and the portion of the resistor (2) that overlaps with the first upper electrode (411) are stacked in this order. The insulating substrate (1), the second upper electrode (421), and the portion of the resistor (2) that overlaps with the second upper electrode (421) are stacked in this order.

[0176] According to this embodiment, a resistor (10A) can be provided in which fluctuations in the resistance value of the resistor (2) are suppressed.

[0177] A resistor (10A) according to the tenth aspect of this disclosure, in the ninth aspect, further comprises a silicone oligomer (A2) as compound (A). The content of polysilsesquioxane (A1) is 90% by mass or more and less than 100% by mass of the total compound (A). The content of silicone oligomer (A2) is more than 0% by mass and 10% by mass or less of the total compound (A).

[0178] In the eleventh aspect of this disclosure, the resistor (10A) has a coating layer (31) with a thickness of 0.5 μm or more and 30.0 μm or less, as described in the ninth or tenth aspect.

[0179] A resistor (10A) according to the twelfth aspect of the present disclosure, in any one of the ninth to eleventh aspects, the terminal group of polysilsesquioxane (A1) includes an ethoxy group.

[0180] A resistor (10A) according to the thirteenth aspect of the present disclosure, in any one aspect from the ninth to the twelfth, has polysilsesquioxane (A1) which is selected from the group consisting of phenyl groups and methyl groups.

[0181] In the resistor (10A) according to the fourteenth aspect of this disclosure, in any one aspect from the ninth to the thirteenth aspect, when the resistor (2) is viewed from above, the covering layer (31) covers the portion of the resistor (2) that does not overlap with the first electrode (41) and the second electrode (42).

[0182] A resistor (10A) according to the fifteenth aspect of the present disclosure, in any one of the nineteenth to fourteenth aspects, has a first electrode (41) located at the end of an insulating substrate (1). A second electrode (42) is located at the end of the insulating substrate (1) opposite to the end on the first electrode (41) side. The first electrode (41) comprises a first end electrode (412) covering the end face of the insulating substrate (1) on the first electrode (41) side, and a first connecting electrode (416) electrically connecting the first end electrode (412) and the first top electrode (411). The second electrode (42) comprises a second end electrode (422) covering the end face of the insulating substrate (1) on the second electrode (42) side, and a second connecting electrode (416) electrically connecting the second end electrode (422) and the second top electrode (421).

[0183] In the resistor (10A) according to the sixteenth aspect of this disclosure, in the fifteenth aspect, the first connecting electrode (416) is in contact with the end of the insulating protective film (3) on the first electrode (41) side. The second connecting electrode (426) is in contact with the end of the insulating protective film (3) on the second electrode (42) side.

[0184] A resistor (10A) according to the seventeenth aspect of this disclosure, in any one of the ninth to sixteenth aspects, further comprises an inorganic protective layer (32) disposed on the resistor (2) as an insulating protective film (3). The resistor (2), the inorganic protective layer (32), and the coating layer (31) are arranged in this order.

[0185] A resistor (10A) according to the eighteenth aspect of this disclosure, in any one of the ninth to sixteenth aspects, further comprises an insulating protective film (3) a resin layer (33) disposed on the coating layer (31). The resistor (2), the coating layer (31), and the resin layer (33) are arranged in this order.

[0186] 1. Insulating substrate 2. Resistor 3. Insulating protective film 10. Resistor 31. Coating layer 32. Inorganic protective layer 33. Resin layer 41. First electrode 411. First internal electrode (first top electrode) 42. Second electrode 421. Second internal electrode (second top electrode)

Claims

1. A resistor comprising an insulating substrate, a first electrode and a second electrode disposed on the insulating substrate, a resistor electrically connecting the first electrode and the second electrode, and an insulating protective film covering the resistor, wherein the insulating protective film has a coating layer containing a cured product of a compound (A) having siloxane bonds and an inorganic filler (B), the compound (A) contains polysilsesquioxane (A1), the content of the cured product of compound (A) is more than 50% by mass and 100% by mass or less of the entire coating layer, and the content of the inorganic filler (B) is 0% by mass or more and less than 50% by mass of the entire coating layer.

2. The resistor according to claim 1, wherein the compound (A) further comprises a silicone oligomer (A2), the content of the polysilsesquioxane (A1) is 90% by mass or more and less than 100% by mass relative to the entire compound (A), and the content of the silicone oligomer (A2) is more than 0% by mass and 10% by mass or less relative to the entire compound (A).

3. The resistor according to claim 1, wherein the thickness of the coating layer is 0.5 μm or more and 30.0 μm or less.

4. The resistor according to claim 1, wherein the terminal group of the polysilsesquioxane (A1) includes an ethoxy group.

5. The resistor according to claim 1, wherein the polysilsesquioxane (A1) has at least one selected from the group consisting of a phenyl group and a methyl group.

6. The resistor according to claim 1, wherein, when the resistor is viewed from above, the covering layer covers the portion of the resistor that does not overlap with the first electrode and the second electrode.

7. The resistor according to any one of claims 1 to 6, wherein the insulating protective film further comprises an inorganic protective layer disposed on the resistor, and the resistor, the inorganic protective layer, and the coating layer are arranged in this order.

8. The resistor according to any one of claims 1 to 6, wherein the insulating protective film further comprises a resin layer disposed on the coating layer, and the resistor, the coating layer, and the resin layer are arranged in this order.

9. The device comprises an insulating substrate, a first electrode and a second electrode disposed on the insulating substrate, a resistor electrically connecting the first electrode and the second electrode, and an insulating protective film covering the resistor, wherein the insulating protective film has a coating layer containing a cured product of a compound (A) having siloxane bonds and an inorganic filler (B), the compound (A) contains polysilsesquioxane (A1), the content of the cured product of compound (A) is more than 50% by mass and 100% by mass or less of the entire coating layer, the content of the inorganic filler (B) is 0% by mass or more and less than 50% by mass of the entire coating layer, the first electrode includes a first upper electrode disposed on the insulating substrate, and the second electrode includes a second upper electrode disposed on the insulating substrate at a distance from the first upper electrode. A resistor wherein the resistor is arranged from at least a portion of the first upper electrode to at least a portion of the second upper electrode, and the insulating substrate, the first upper electrode, and the portion of the resistor overlapping the first upper electrode are stacked in this order, and the insulating substrate, the second upper electrode, and the portion of the resistor overlapping the second upper electrode are stacked in this order.

10. The resistor according to claim 9, wherein the compound (A) further comprises a silicone oligomer (A2), the content of the polysilsesquioxane (A1) is 90% by mass or more and less than 100% by mass relative to the entire compound (A), and the content of the silicone oligomer (A2) is more than 0% by mass and 10% by mass or less relative to the entire compound (A).

11. The resistor according to claim 9, wherein the thickness of the coating layer is 0.5 μm or more and 30.0 μm or less.

12. The resistor according to claim 9, wherein the terminal group of the polysilsesquioxane (A1) includes an ethoxy group.

13. The resistor according to claim 9, wherein the polysilsesquioxane (A1) has at least one selected from the group consisting of a phenyl group and a methyl group.

14. The resistor according to claim 9, wherein, when the resistor is viewed from above, the covering layer covers the portion of the resistor that does not overlap with the first electrode and the second electrode.

15. The resistor according to claim 9, wherein the first electrode is disposed at the end of the insulating substrate, the second electrode is disposed at the end of the insulating substrate opposite to the end on the first electrode side, the first electrode comprises a first end electrode covering the end face on the first electrode side of the insulating substrate, and a first connecting electrode electrically connecting the first end electrode and the first top electrode, and the second electrode comprises a second end electrode covering the end face on the second electrode side of the insulating substrate, and a second connecting electrode electrically connecting the second end electrode and the second top electrode.

16. The resistor according to claim 15, wherein the first connecting electrode is in contact with the end of the insulating protective film on the first electrode side, and the second connecting electrode is in contact with the end of the insulating protective film on the second electrode side.

17. The resistor according to any one of claims 9 to 16, wherein the insulating protective film further comprises an inorganic protective layer disposed on the resistor, and the resistor, the inorganic protective layer, and the coating layer are arranged in this order.

18. The resistor according to any one of claims 9 to 16, wherein the insulating protective film further comprises a resin layer disposed on the coating layer, and the resistor, the coating layer, and the resin layer are arranged in this order.

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