Electronic components and capacitors

Abstract

The present invention provides an electronic component having excellent moisture resistance. The electronic component includes an electronic component element 2 and a barrier layer 3 that seals the electronic component element 2. The barrier layer 3 includes a clay layer 31 containing clay. The clay layer 31 is provided to surround the electronic component element 2. The clay layer 31 reduces the amount of moisture that passes through the barrier layer 3. The barrier layer 3 includes a resin layer 32 containing resin. The clay layer 31 and the resin layer 32 are preferably laminated. The thickness of the resin layer 32 is preferably greater than the thickness of the clay layer 31.

Description

Technical Field

[0001] The present disclosure relates generally to electronic components and capacitors, and more particularly to electronic components and capacitors including electronic component elements and barrier layers. Background Art

[0002] Patent Document 1 discloses a case-molded capacitor. This case-molded capacitor includes a capacitor element, lead terminals, a molding resin, and a case. The capacitor element is a wound film capacitor element and is housed in a case made of polyphenylene sulfide (PPS). The molding resin fills the void inside the case and encapsulates the capacitor element. The lead terminals are electrically connected to the capacitor element and extend out of the case through portions of the molding resin.

[0003] Reference List

[0004] Patent Literature

[0005] Patent Document 1: JP 2006-294788 A Summary of the Invention

[0006] The case-molded capacitor of Patent Document 1 attempts to protect the capacitor element from humid environments using a molded resin and a case. However, to ensure sufficient moisture resistance (or moisture resistance), the thickness of the case and the molded resin must be increased, which requires a large amount of resin. This makes it difficult to reduce the overall size of the capacitor.

[0007] Therefore, an object of the present disclosure is to provide an electronic component and a capacitor, both of which can be easily reduced in overall size.

[0008] An electronic component according to one aspect of the present disclosure includes: an electronic component element; and a barrier layer encapsulating the electronic component element. The barrier layer includes a clay layer containing clay. The clay layer is provided to surround the electronic component element.

[0009] A capacitor according to another aspect of the present disclosure includes a capacitor element as the electronic component element of the above-mentioned electronic component. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A is a front view showing an electronic component according to an exemplary embodiment of the present disclosure;

[0011] Figure 1 B is a cross-sectional view showing the electronic component according to this exemplary embodiment;

[0012] Figure 1 C is a cross-sectional view showing an electronic component according to this exemplary embodiment;

[0013] Figure 2 A is a cross-sectional view showing an electronic component according to this exemplary embodiment;

[0014] Figure 2 B is a cross-sectional view showing the electronic component according to this exemplary embodiment;

[0015] Figure 2 C is a cross-sectional view showing an electronic component according to this exemplary embodiment;

[0016] Figure 3 A is a schematic perspective view showing an exemplary mineral particle;

[0017] Figure 3 B is a schematic cross-sectional view showing an exemplary clay layer;

[0018] Figure 4 A is a perspective view showing a process step of a method for manufacturing a wound-type capacitor element;

[0019] Figure 4 B is a perspective view of a wound capacitor element;

[0020] Figure 5 A is a perspective view showing a process step of a method for manufacturing a stacked capacitor element;

[0021] Figure 5 B is a partial cross-sectional perspective view of a stacked capacitor element;

[0022] Figure 5 C is a perspective view of a stacked capacitor element;

[0023] Figure 6 A and 6B are shown Figure 1 A–C is a cross-sectional view of the manufacturing process of the electronic component shown in FIG.

[0024] Figure 7 A is a cross-sectional view showing an electronic component according to a second embodiment of the present disclosure;

[0025] Figure 7 B is a cross-sectional view showing an electronic component according to a second embodiment;

[0026] Figure 7 C is a cross-sectional view showing an electronic component according to a second embodiment;

[0027] Figure 8 A–8C are shown Figure 7 A–C is a cross-sectional view of the manufacturing process of the electronic component shown in FIG.

[0028] Figure 9A is a cross-sectional view showing an electronic component according to a third embodiment of the present disclosure;

[0029] Figure 9 B is a cross-sectional view showing an electronic component according to a fourth embodiment of the present disclosure; and

[0030] Figure 9 C is a cross-sectional view showing an electronic component according to a fifth embodiment of the present disclosure. DETAILED DESCRIPTION

[0031] (First embodiment)

[0032] (1) Summary

[0033] The electronic component 1 according to the exemplary embodiment includes an electronic component element 2 and a barrier layer 3 (see Figure 1 A). Barrier layer 3 includes a clay layer 31 containing clay. Clay layer 31 is provided to surround electronic component element 2. In this configuration, electronic component 1 includes clay layer 31 in barrier layer 3, which prevents water from permeating through it as smoothly as a layer composed solely of resin and having the same thickness as barrier layer 3. That is, clay layer 31 has a labyrinthine structure, thereby allowing a smaller amount of water to permeate through it per unit thickness than a layer composed solely of resin and having the same thickness as barrier layer 3. Therefore, barrier layer 3 including clay layer 31 can more significantly reduce water permeation than a resin layer composed solely of resin (i.e., not including clay layer 31) and having the same thickness as barrier layer 3. This enables electronic component 1 to be more effectively miniaturized by reducing the size of barrier layer 3 while ensuring sufficient moisture resistance using barrier layer 3.

[0034] For example, if the electronic component is a thin film capacitor, the electronic component element is implemented as a thin film capacitor element. A thin film capacitor element can be formed, for example, by first forming a very thin aluminum vapor-deposited electrode (20–30 nm thick) on a dielectric film, then winding two such dielectric films, each with a vapor-deposited electrode, into a roll while shifting them relative to each other, and then forming external electrodes on both ends of the roll using a metallization (Metallikon) thermal spray process.

[0035] The vapor-deposited electrodes of such film capacitor elements are too thin to exhibit sufficient moisture resistance (i.e., resistance to water penetrating the film capacitor). Consequently, these vapor-deposited electrodes are sometimes oxidized by water, affecting their electrode function and thus degrading the characteristics of the film capacitor. This is why conventional techniques protect film capacitor elements from water by housing them in a resin case and filling the voids in the case with an encapsulating resin.

[0036] However, if epoxy resin is used solely for the resin case and as an encapsulating resin, even the thinnest parts of the case and encapsulating resin must be at least 2mm. Consequently, film capacitors using epoxy resin for both cases and encapsulating resins are so heavy that their manufacturing methods tend to be extremely complex. Furthermore, if film capacitors are designed for automotive use, their shape is custom-designed and varies depending on the vehicle model. Consequently, film capacitors are a product that makes reducing manufacturing costs difficult.

[0037] In contrast, the electronic component 1 according to this embodiment includes a clay layer 31 containing clay in the barrier layer 3 that encapsulates the electronic component element 2. This makes it easier to reduce the amount of water that permeates the barrier layer compared to a barrier layer made solely of resin and having the same thickness as the aforementioned barrier layer. This reduces the amount of water that enters the electronic component element 2 from outside the electronic component 1 and reduces the likelihood of the electronic component element 2 being affected by water, thereby making it easier to provide an electronic component 1 with excellent moisture resistance. Furthermore, the clay layer 31 can be formed by simple means such as coating, reducing the likelihood of overly complex manufacturing processes for the electronic component 1 and thus making it easier to reduce costs.

[0038] (2) Details

[0039] (2.1) Construction

[0040] like Figure 1 As shown in A, the electronic component 1 according to the present embodiment includes an electronic component element 2 and a barrier layer 3 that encapsulates the electronic component element 2. The electronic component element 2 is a component or part that enables the electronic component 1 to perform its intended function. The barrier layer 3 has the ability to protect the electronic component element 2. For example, the barrier layer 3 may have the ability to protect the electronic component element 2 from water. Alternatively, for example, the barrier layer 3 may also have the ability to protect the electronic component element 2 from heat, light, electromagnetic waves, impact or chemicals. The barrier layer 3 is configured to completely cover the electronic component element 2 except for the portion through which the external connection terminal 4 extends. In other words, the electronic component element 2 is completely covered and protected by the barrier layer 3 except for the portion having the external connection terminal 4.

[0041] Next, a case will be described where the electronic component 1 is a capacitor 10. The electronic component 1 implemented as the capacitor 10 includes the capacitor element 20 as its electronic component element 2. That is, the electronic component element 2 included in the capacitor 10 is the capacitor element 20.

[0042] For example, the external connection terminals 4 are terminals for electrically connecting the capacitor 10 to the circuit board. One end portion (i.e., the basal end portion) of each of the external connection terminals 4 is electrically and mechanically connected to the external electrode 21 of the capacitor element 20 at the same time. The other end portion (i.e., the tip portion) of each of the external connection terminals 4 is located outside the barrier layer 3. The external connection terminals 4 can be made of, for example, copper or a copper alloy and formed into a plate shape. The capacitor 10 according to the present embodiment includes a pair of external connection terminals 4, and the tip portion of each of the external connection terminals 4 protrudes outward (e.g., upward) from the same surface (e.g., the upper surface) of the barrier layer 3. Note that this shape and structure are merely examples and should not be interpreted as restrictive.

[0043] <Barrier Layer>

[0044] The barrier layer 3 has the ability to protect the capacitor element 20 from water. Alternatively, for example, the barrier layer 3 may also have the ability to protect the capacitor element 20 from heat, light, electromagnetic waves, impact or chemicals. Figure 1 As shown in Figures 1B, 1C, 2A, 2B, and 2C, the barrier layer 3 is configured to completely cover the capacitor element 20 except for the portion through which the external connection terminal 4 extends. In other words, the capacitor element 20 is completely covered and protected by the barrier layer 3 except for the portion having the external connection terminal 4.

[0045] <Clay layer>

[0046] The barrier layer 3 includes a clay layer 31 containing clay. The clay layer 31 is formed in the shape of a layer containing clay. As used herein, "clay" refers to an aggregate of multiple mineral particles 311. In addition, in clay, the aggregate of multiple mineral particles 311 may contain a small amount of water. The mineral particles 311 include at least one selected from the group consisting of mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite and nontronite. In particular, the mineral particles 311 preferably include montmorillonite, which is a clay material with high moisture resistance.

[0047] The crystal structure of montmorillonite uses an octahedral structure (centered on an Al (aluminum) atom) between a tetrahedral structure (each centered on a Si (silicon) atom) as a single layer structure. Specifically, some trivalent Al atoms are replaced by divalent Mg or Fe atoms, making the single layer negatively charged. Therefore, for the purpose of charge compensation, cations such as Na + and Ca 2+When montmorillonite is dispersed in water, the cationic portion of the montmorillonite is further hydrated and can be separated on a monolayer basis. Therefore, it is easy to separate montmorillonite into a monolayer by dispersing montmorillonite in water. This makes it easier for the montmorillonite to separate into a monolayer and be contained in the clay layer 31, and form a maze structure composed of mineral particles 311 in the clay layer 31.

[0048] In montmorillonite, interlayer exchangeable cations can be easily exchanged with other inorganic or organic cations. This makes it possible to improve the affinity of montmorillonite for organic solvents and to embed various compounds into its interlayer sites. In addition, the presence of hydroxide groups on the end faces of the crystals makes it possible to modify montmorillonite with any of a variety of silanizing agents. In addition, in order to impart high moisture resistance to the clay layer 31, it is preferred to make the clay layer 31 hydrophobic. For example, exchangeable cations (such as Na + ) has a high affinity for water. Therefore, the presence of such exchangeable cations at the interlayer sites is generally not conducive to making the clay layer 31 hydrophobic. Therefore, as an alternative measure, the exchangeable cations can be replaced with Li and protons. For example, if montmorillonite is heat-treated, the ions will move to the interior and surface of the crystals, making it easier to make the clay layer 31 hydrophobic.

[0049] Figure 3 A is a schematic stereoscopic view of a single mineral particle 311. In the present embodiment, the mineral particle 311 is a plate-like or flake-like particle. That is, the mineral particle 311 is a particle whose thickness (a) is less than its lateral width (b). As used herein, the lateral width (b) refers to the size of the longest part of the mineral particle 311 in the front view of the mineral particle 311 (i.e., when the mineral particle 311 is viewed from directly in front of the mineral particle 311 in the thickness direction). If the mineral particle 311 has a disc shape, its diameter is its lateral width (b). On the other hand, the thickness (a) refers to the dimension measured in a direction perpendicular to the lateral width (b), and is the dimension measured between two opposite surfaces of the mineral particle 311.

[0050] In the present embodiment, the mineral particles 311 have a high aspect ratio. That is, the aspect ratio (defined as the ratio of lateral width (b) to thickness (a)) of the mineral particles 311 is high. The aspect ratio is determined by measuring the thickness (a) and lateral width (b) of the mineral particles 311. For example, the thickness (a) is measured using a transmission electron microscope (TEM). However, the same type of mineral particles 311 has a substantially uniform single layer thickness. Therefore, there is no need to measure the thickness a of each of the mineral particles 311. For example, for montmorillonite, its thickness (a) is about 1 nm. The lateral width (b) can be measured using, for example, an atomic force microscope (AFM). The size of the longest part of the mineral particle 311 found when observing the flat part is estimated to be the lateral width (b).

[0051] Figure 3 B is a schematic cross-sectional view of the clay layer 31. The clay layer 31 contains mineral particles 311 and a binder 312. In other words, the clay layer 31 can be composed of the mineral particles 311 and the binder 312. Alternatively, the clay layer 31 can contain the mineral particles 311, the binder 312 and other additives. The binder 312 includes at least one selected from the group consisting of polypropylene, polyolefin sulfide, polyimide, polyamide, polyethylene terephthalate, epoxy resin, fluororesin, polyester resin, polyurethane resin, acrylic resin, phenoxy resin, polyacetal and polyvinyl alcohol. Optionally, the binder 312 can also be a binder resin that can be used as a coating or slurry varnish. In particular, considering the ease with which the binder 312 forms the clay layer 31 and the adhesion between the binder 312 and the mineral particles 311, the binder 312 is preferably a polyamide, polyimide, polyurethane resin, epoxy resin or phenoxy resin. Optionally, a suitable curing agent (crosslinking agent) may also be used for the resin. In this case, the binder 312 is made of a crosslinked resin and can improve the moisture resistance of the clay layer 31.

[0052] The clay layer 31 is formed by dispersing a plurality of mineral particles 311 in a binder 312. The mineral particles 311 are dispersed so that their thickness is substantially consistent with the thickness of the clay layer 31. The gaps left between the plurality of mineral particles 311 adjacent to each other in the thickness direction are filled with the binder 312. The gaps left between the plurality of mineral particles 311 adjacent to each other in a direction perpendicular to the thickness direction are also filled with the binder 312. It can be seen that the clay layer 31 has a maze-like structure (i.e., a maze structure) in which passages are formed between the plurality of mineral particles 311. That is, the plurality of mineral particles 311 are dispersed in the clay layer 31 so as to be located in random positions in the width direction while having their thickness consistent with the thickness of the clay layer 31. Therefore, a zigzag passage is formed between adjacent mineral particles 311. Therefore, water W passing through the clay layer 31 in the thickness direction cannot travel in a straight line, but needs to travel in a zigzag shape through the gaps between adjacent mineral particles 311 (e.g., a gap between adjacent mineral particles 311). Figure 3 (Indicated by the dotted line in B). Therefore, compared to a resin layer that does not contain mineral particles (i.e., a layer composed solely of a binder), clay layer 31 allows water W to pass through it less smoothly, thereby ensuring sufficient moisture resistance for capacitor 10 even if the thickness of barrier layer 3 is reduced. For example, even a clay layer 31 with a thickness ranging from several μm to several tens of μm enables capacitor 10 to exhibit moisture resistance as high as that of a resin layer made solely of epoxy resin and having a thickness of 2 mm. Therefore, capacitor 10 according to this embodiment can sometimes achieve moisture resistance that is 1,000 times greater than that of a barrier layer made solely of resin.

[0053] The labyrinth structure of the clay layer 31 is theoretically expressed by the following formula (1):

[0054] P / P0 = (1 – Φ) / (1 + 0.5AΦ) (1)

[0055] Wherein P / P0 represents the specific permeability, Φ represents the volume fraction of the mineral particles 311 in the clay layer 31 , and A represents the aspect ratio of the mineral particles 311 .

[0056] The smaller the P / P0 value, the less smoothly water passes through the clay layer 31. The larger the P / P0 value, the more smoothly water passes through the clay layer 31. Therefore, the larger the Φ value in formula (1), the less smoothly water passes through the clay layer 31. The smaller the Φ value in formula (1), the more smoothly water passes through the clay layer 31. In addition, the larger the A value in formula (1), the less smoothly water passes through the clay layer 31. The smaller the A value in formula (1), the more smoothly water passes through the clay layer 31. Therefore, in order to provide a barrier layer 3 that does not allow water to pass through smoothly to improve the moisture resistance of the capacitor 10, the volume fraction of the mineral particles 311 relative to the clay layer 31 is preferably increased. Alternatively or additionally, the content of the mineral particles 311 having a high aspect ratio is preferably increased.

[0057] The aspect ratio of mineral particles 311 is preferably equal to or greater than 20. In order to provide a clay layer 31 that does not allow water to pass smoothly therethrough, it is preferable to use mineral particles 311 having an even higher aspect ratio. This range is preferable in consideration of other characteristics of the clay layer 31, such as the mechanical strength, adhesion, and formability of the clay layer 31. The aspect ratio of mineral particles 311 is more preferably equal to or greater than 100, and even more preferably equal to or greater than 150. The upper limit of the aspect ratio of mineral particles 311 is not limited to any particular value, but is appropriately set in consideration of the dispersibility of the mineral particles 311 in the clay layer 31 and other factors.

[0058] Optionally, a material having a high aspect ratio and a material having a low aspect ratio may be used in combination for mineral particles 311. This allows the material having a low aspect ratio (i.e., mineral particles having a small diameter) to more easily enter the gaps between the particles of the material having a high aspect ratio, thereby enabling an increase in the filling rate of mineral particles 311 in clay layer 31. When a material having a high aspect ratio and a material having a low aspect ratio are used in combination, the material having a high aspect ratio preferably accounts for at least half of the total mass of mineral particles 311 contained in clay layer 31.

[0059] The content of mineral particles 311 in the clay layer 31 is preferably equal to or greater than 50% by mass relative to the total mass of the clay layer 31. For example, if the clay layer 31 is composed of mineral particles 311 and a binder 312, the content of mineral particles 311 is preferably equal to or greater than 50% by mass and equal to or less than 95% by mass relative to the total mass of the clay layer 31, and the content of binder 312 is preferably equal to or greater than 5% by mass and equal to or less than 50% by mass relative to the total mass of the clay layer 31. This makes it easier to provide a clay layer 31 that does not allow water to pass smoothly therethrough while ensuring sufficient performance in terms of mechanical strength, adhesion, formability, and other parameters of the clay layer 31.

[0060] The thickness of the clay layer 31 is preferably equal to or greater than 0.5 μm and equal to or less than 100 μm. To reduce the amount of water that permeates through the clay layer 31, the clay layer 31 is preferably as thick as possible. However, considering the characteristics of the clay layer 31, such as mechanical strength, adhesion, and formability, this range is preferred. The thickness of the clay layer 31 is more preferably equal to or greater than 0.5 μm and equal to or less than 50 μm, and even more preferably equal to or greater than 0.5 μm and equal to or less than 10 μm.

[0061] like Figure 1 B and 1C and Figure 2As shown in A-2C, the clay layer 31 is arranged to surround the electronic component element 2. That is, the clay layer 31 is arranged to surround the capacitor element 20. The clay layer 31 is preferably arranged to completely surround the capacitor element 20 except for the portion through which the external connection terminal 4 extends. This reduces the possibility of water entering the capacitor element 20 from the entire periphery of the capacitor element 20, thereby improving the moisture resistance of the capacitor 10. In particular, the outer peripheral surface of the capacitor element 20 (i.e., the surface surrounding its axis) generally has a larger area than its end face (i.e., the surface in the axial direction). Therefore, it is preferred that the clay layer 31 is arranged to surround at least the outer peripheral surface of the capacitor element 20. As described above, the clay layer 31 is formed to substantially surround the entire surface of the capacitor element 20. As used herein, the phrase "substantially the entire surface" refers to more than 80% of the total surface area of ​​the outer surface of the capacitor element 20 excluding its external electrode 21.

[0062] Note that the clay layer 31 has not only low moisture permeability but also low gas permeability, thereby making it easier for the barrier layer 3 to also ensure sufficient gas barrier properties.

[0063] <Resin Layer>

[0064] The barrier layer 3 also includes a resin layer 32 containing a resin. That is, the barrier layer 3 is a composite material layer including both the clay layer 31 and the resin layer 32. Optionally, the barrier layer 3 may further include other layers in addition to the clay layer 31 and the resin layer 32. Furthermore, the clay layer 31 and the resin layer 32 are stacked on top of each other. That is, the clay layer 31 and the resin layer 32 are arranged to face each other along the thickness direction of the barrier layer 3. Although the clay layer 31 and the resin layer 32 are stacked in contact with each other in this embodiment, the clay layer 31 and the resin layer 32 may also be stacked on top of each other with another layer interposed therebetween.

[0065] Resin layer 32 is preferably thicker than clay layer 31. This makes it easier to protect thin and easily broken clay layer 31 with resin layer 32. The thickness of resin layer 32 is preferably equal to or greater than 1 mm and equal to or less than 6 mm. This allows resin layer 32 and clay layer 31 to more easily reduce the moisture permeability of barrier layer 3, thereby improving the moisture resistance of capacitor 10. The thickness of resin layer 32 is more preferably equal to or greater than 1 mm and equal to or less than 4.5 mm, and even more preferably equal to or greater than 1 mm and equal to or less than 3 mm.

[0066] like Figure 1 B and 1C and Figure 2As shown in A-2C, the resin layer 32 is closer to the electronic component element 2 than the clay layer 31. That is, in the thickness direction defined with respect to the barrier layer 3, the resin layer 32 is arranged inside the clay layer 31 (i.e., closer to the capacitor element 20), and the clay layer 31 is arranged outside the resin layer 32 (i.e., on the opposite side of the capacitor element 20 relative to the resin layer 32). As will be described later, the clay layer 31 is generally formed by applying a coating containing mineral particles 311, a binder 312, and water. Therefore, it is preferable to reduce the possibility that the capacitor element 20 is affected by the water contained in the coating used to form the clay layer 31. Therefore, setting the resin layer 32 closer to the capacitor element 20 than the clay layer 31 reduces the possibility of the water contained in the coating coming into contact with the capacitor element 20 when forming the clay layer 31 due to the presence of the resin layer 32. This makes it easier to reduce the degradation of the capacitor element 20 caused by exposure to water. If the clay layer 31 is formed to completely surround the capacitor element 20 except for those portions thereof having the external connection terminals 4 , the clay layer 31 is formed to cover the outer surface of the resin layer 32 except for those portions thereof having the external connection terminals 4 .

[0067] Examples of the resin contained in the resin layer 32 include epoxy resins, unsaturated polyester resins, and polyimide resins. In particular, epoxy resin is preferred in view of the moldability when encapsulating the capacitor element 20. In addition, the resin layer 32 may be made of resin alone. Alternatively, the resin layer 32 may also be made of a composite material comprising a resin and a filler. In this case, for example, silicon dioxide may be used as a filler. The content of the filler may be equal to or greater than 1% by mass and equal to or less than 99% by mass relative to the total mass of the resin layer 32.

[0068] (2.2) Manufacturing method

[0069] The method for manufacturing the capacitor 10 according to the present embodiment includes an element forming step, a resin encapsulation (resin molding) step, and a clay layer forming step. The element forming step is a step of forming the capacitor element 20. The resin encapsulation step is a step of encapsulating the capacitor element 20 formed in the element forming step with a resin layer 32. The clay layer forming step is a step of forming a clay layer 31 on the outer surface (i.e., the surface opposite to the capacitor element 20) of the resin layer 32 formed in the resin encapsulation step.

[0070] Figure 4Figures 4A and 4B illustrate the steps of forming a wound capacitor element 20 as an example element formation step. The wound capacitor element 20 includes a pair of metallized films 24, wherein in each metallized film, an electrode film 23 is formed on a dielectric film 22. The dielectric film 22 can be, for example, a resin film having electrical insulation properties, and can be made of, for example, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, or polystyrene. The dielectric film 22 is a long film. The electrode film 23 is formed on one side of the dielectric film 22 except for the edge portion 25. The edge portion 25 is a portion where the dielectric film 22 is exposed, and is formed in a strip along one long side of the dielectric film 22, the width of the strip being narrower than the width of the electrode film 23. The electrode film 23 is formed by a process such as an evaporation process or a sputtering process. The electrode film 23 can be made of, for example, aluminum, zinc, or magnesium.

[0071] Next, a pair of metallized films 24 are wound into a roll so that the electrode films 23 face each other with the dielectric film 22 interposed therebetween. Figure 4 As shown in FIG. 2A , the pair of metallized films 24 are stacked on each other with their two long sides aligned with each other. In addition, the dielectric film 22 is interposed between one electrode film 23 and the other electrode film 23. Furthermore, the metallized films 24 are arranged so that the edge portions 25 on the respective long sides of the pair of metallized films 24 are located on two opposite sides. A cylindrical roll 26 is obtained by winding the metallized films 24 stacked on each other in this manner. Next, the roll 26 is pressed from both sides thereof and converted into a roll 27 having an elliptical cross section (see FIG. 2B ). Figure 4 B).

[0072] Next, an external electrode 21 is formed on each of the two ends of the coil 27 by metal spraying (metal thermal spraying), thereby obtaining a wound capacitor element 20. Each external electrode 21 is electrically connected to a corresponding electrode film in the electrode films 23. This pair of electrode films 23 forms a pair of internal electrodes. The external electrodes 21 are made of, for example, aluminum, zinc, magnesium, tin, or an alloy thereof. Thereafter, as Figure 4 As shown in FIG. B, the external connection terminals 4 are electrically connected to the two external electrodes 21. Examples of the connection method include soldering, resistance welding, and ultrasonic welding.

[0073] On the other hand, for example, the laminated capacitor element 20 can be manufactured in the following manner. First, a plurality of metallized films 24 (see Figure 5 A).

[0074] Each metallized film 24 includes a dielectric film 22 and an electrode film 23. Dielectric film 22 has a rectangular shape. Electrode film 23 is formed on one side of dielectric film 22, excluding edge portion 25. Edge portion 25 is formed into a strip along one side of dielectric film 22, with the width of the strip being narrower than that of electrode film 23. Dielectric film 22 and electrode film 23 are made of the same material as that of wound capacitor element 20.

[0075] Next, if Figure 5 As shown in FIG. 2A , a plurality of metallized films 24 are stacked on top of each other so that their four sides are aligned with each other. In this case, the dielectric film 22 is interposed between each pair of adjacent electrode films 23. In addition, in each pair of adjacent metallized films 24, one metallized film 24 is arranged so that its edge portion 25 is located at the rear, and the other metallized film 24 is arranged so that its edge portion 25 is located at the front. A structure such as the following can be obtained by stacking a plurality of metallized films 24 on top of each other and integrating the metallized films 24 together. Figure 5 B and 5C show a multilayer laminate 28. The multilayer laminate 28 is completely covered with a protective film 29 except for its front and rear surfaces. The protective film 29 is a film having electrical insulating properties.

[0076] Next, external electrodes 21 are formed on each of the front and rear surfaces of the multilayer laminate 28 by metal spraying (metal thermal spraying), thereby obtaining a laminated capacitor element 20. Each external electrode 21 is electrically connected to a corresponding electrode film 23. A pair of electrode films 23 form a pair of internal electrodes. The external electrodes 21 are made of, for example, aluminum, zinc, magnesium, tin, or an alloy thereof. Thereafter, as Figure 5 As shown in FIG. B, the external connection terminals 4 are electrically connected to the two external electrodes 21. Examples of the connection method include soldering, resistance welding, and ultrasonic welding.

[0077] After the element forming step is performed, a resin encapsulation step is performed. The resin encapsulation step includes encapsulating the capacitor element 20 formed in the element forming step with a resin to form a resin layer 32 (see Figure 6 A). Examples of resins include epoxy resins, unsaturated polyester resins, polyimide resins, polyurethane resins, and silicone resins. Examples of molding methods when encapsulating the capacitor element 20 include transfer molding, compression molding, and lamination molding. Optionally, the capacitor element 20 can be housed in a housing having a resin layer 32 and encapsulated. The resin layer 32 is formed to completely cover the capacitor element 20 except for the connection portion between the capacitor element 20 and the external connection terminal 4. The top end of each external connection terminal 4 is located outside the resin layer 32 (i.e., on the opposite side of the capacitor element 20).

[0078] After the resin encapsulation step is performed, a clay layer forming step is performed. The clay layer forming step includes forming a clay layer 31 (see Figure 6 B) The clay layer 31 is formed by supplying a treatment liquid containing mineral particles 311 and a binder 312 onto the surface of the resin layer 32, and drying the treatment liquid on the surface of the resin layer 32. In the treatment liquid, the mineral particles 311 and the binder 312 are dispersed in a solvent. The solvent can be water, an organic solvent, or a mixture thereof. Considering its manageability during waste disposal, the solvent is preferably water. When supplying the treatment liquid to the surface of the resin layer 32, a coating technique such as brushing or spraying, or an impregnation technique such as immersion, can be employed. This makes it easier to supply the treatment liquid even if the surface of the resin layer 32 has some unevenness, thereby making it easier to form the clay layer 31. The treatment liquid is supplied so as to surround the capacitor element 20. For example, it is preferable to supply the treatment liquid to the entire outer surface of the resin layer 32, excluding those portions having the external connection terminals 4. For example, the treatment liquid can be dried by natural drying or heat drying.

[0079] This manufacturing method enables the formation of a clay layer that exhibits excellent moisture resistance despite its small thickness (on the order of several μm to tens of μm), ensures sufficient moisture resistance of the barrier layer 3 even if the thickness of the resin layer 32 is reduced, and helps to reduce the size and weight of the capacitor 10 by providing a thinner resin layer 32.

[0080] (3) Change plan

[0081] Note that the first embodiment described above is merely an exemplary embodiment among the various embodiments of the present disclosure and should not be construed as limiting. Rather, the first exemplary embodiment can be easily modified in various ways according to design choices or any other factors without departing from the scope of the present disclosure.

[0082] In the above description, the electronic component is a capacitor. However, this is merely an example and should not be construed as limiting. Alternatively, the present disclosure is also applicable to cases where the electronic component is a passive component or an active component other than a capacitor. Passive components other than capacitors include passive elements selected according to the type of electronic component, rather than capacitor elements. Active components other than capacitors include active elements selected according to the type of electronic component, rather than capacitor elements.

[0083] In the above description, the capacitor is described as a film capacitor. However, this is merely an example and should not be construed as limiting. Rather, the present disclosure is also applicable to capacitors other than film capacitors. For example, the capacitor may also be a solid electrolytic capacitor. In this case, the capacitor element has a solid electrolyte.

[0084] (Second embodiment)

[0085] The electronic component 1 according to the second embodiment is different from the electronic component 1 according to the first embodiment in the configuration of the barrier layer 3 .

[0086] In the following description, any constituent elements of the second embodiment having the same functions as those of the corresponding parts in the above-described first embodiment will be denoted by the same reference numerals as those of the corresponding parts, and description thereof will be appropriately omitted herein.

[0087] Note that the configuration described below with respect to the second embodiment can be used in combination with the configuration described with respect to the first embodiment (including variations thereof) as appropriate.

[0088] Figure 7 Figures 7A-7C illustrate a capacitor 10 as an exemplary electronic component 1 according to the second embodiment. In this capacitor 10, the barrier layer 3 also includes a clay layer 31 and a resin layer 32, but the clay layer 31 is not provided on the outer surface of the resin layer 32. Instead, the clay layer 31 is provided on the inner surface of the resin layer 32 (i.e., the surface facing the capacitor element 20). In other words, the clay layer 31 is located between the resin layer 32 and the capacitor element 20. Therefore, in the thickness direction defined with respect to the barrier layer 3, the clay layer 31 is closer to the electronic component element 2 (capacitor element 20) than the resin layer 32.

[0089] The clay layer 31 completely covers the outer surface of the electronic component element 2 (capacitor element 20) except for those portions of the external electrode 21. That is, the clay layer 31 is formed not only on the outer peripheral surface of the roll 27 of the capacitor element 20 or on the surface of the protective film 29, but also on the outer surface of the external electrode 21. In this case, the outer surface of the external electrode 21 includes the connection portion where the external electrode 21 is connected to the external connection terminal 4, so the clay layer 31 is not formed on those connection portions of the outer surface of the external electrode 21.

[0090] To form such a capacitor 10, first, the capacitor element 20 is formed by performing the element forming step in the same manner as described above, and the external connection terminal 4 is simultaneously electrically and mechanically connected to the external electrode 21 by, for example, welding (see FIG. Figure 8A). Next, in the clay layer forming step, a treatment liquid containing mineral particles 311 and a binder 312 is supplied to the outer surface of the capacitor element 20 and dried, thereby forming a clay layer 31 surrounding the capacitor element 20 (refer to Figure 8 B) Thereafter, in a resin encapsulation step, resin layer 32 is formed on the outer surface of clay layer 31 , thereby enabling encapsulation of capacitor element 20 with barrier layer 3 in which clay layer 31 and resin layer 32 are laminated to each other.

[0091] This capacitor 10 includes a resin layer 32 outside a clay layer 31. Therefore, the resin layer 32 can prevent the thin clay layer 31 from being mechanically damaged by an external force, thereby reducing the possibility of causing a decrease in the moisture resistance reliability of the capacitor 10.

[0092] (Third embodiment)

[0093] The electronic component 1 according to the third embodiment is different from the electronic component 1 according to the first embodiment or the second embodiment in the configuration of the barrier layer 3 .

[0094] In the following description, any constituent elements of the third embodiment having the same function as the corresponding parts in the above-mentioned first embodiment or second embodiment will be denoted by the same reference numerals as the reference numerals of the corresponding parts, and their descriptions will be appropriately omitted herein.

[0095] Note that the configuration described below with respect to the third embodiment can be used in combination with the configuration described with respect to the first embodiment or the second embodiment (including variations thereof) as appropriate.

[0096] Figure 9 Figure A shows a capacitor 10 as an electronic component 1 according to the third embodiment. This capacitor 10 includes not only each component of the capacitor 10 according to the second embodiment described above, but also includes an additional clay layer 31 disposed on the outer surface of a resin layer 32. Specifically, the barrier layer 3 includes a first clay layer 31a and a second clay layer 31b as the clay layer 31. Like the clay layer 31 according to the second embodiment, the first clay layer 31a is formed to surround the capacitor element 20. Similarly, like the resin layer 32 according to the second embodiment, the resin layer 32 is formed to cover the first clay layer 31a. Furthermore, the second clay layer 31b is formed on the outer surface of the resin layer 32 to completely surround the capacitor element 20. It can be seen that, when viewed from the capacitor element 20, the barrier layer 3 has a structure in which the first clay layer 31a, the resin layer 32, and the second clay layer 31b are stacked one on top of another in the thickness direction defined with respect to the barrier layer 3.

[0097] This capacitor 10 encapsulates the capacitor element 20 with the barrier layer 3 including two clay layers 31, thereby further reducing the passage of water through the barrier layer 3 in the thickness direction and further reducing the possibility of degradation of the moisture resistance reliability of the capacitor 10 compared to the capacitor 10 including a single clay layer 31 according to the first embodiment.

[0098] (Fourth Implementation Plan)

[0099] The electronic component 1 according to the fourth embodiment is different from the electronic component 1 according to the first embodiment, the second embodiment, or the third embodiment in the configuration of the barrier layer 3 .

[0100] In the following description, any constituent elements of the present fourth embodiment that have the same function as the corresponding parts in the above-mentioned first embodiment, second embodiment or third embodiment will be represented by the same figure marks as the figure marks of the corresponding parts, and their descriptions will be appropriately omitted in this document.

[0101] Note that the configuration described below with respect to the fourth embodiment can be used in combination with the configuration described with respect to the first embodiment, the second embodiment, or the third embodiment (including variations thereof), as appropriate.

[0102] Figure 9 B shows a capacitor 10 as an electronic component 1 according to the fourth embodiment. This capacitor 10 not only includes each component of the capacitor 10 according to the first embodiment described above, but also includes an additional resin layer 32 provided on the outer surface of a clay layer 31. That is, the barrier layer 3 includes a first resin layer 32a and a second resin layer 32b as resin layers 32. Like the resin layer 32 according to the first embodiment, the first resin layer 32a is formed to encapsulate the capacitor element 20. Like the clay layer 31 according to the first embodiment, the clay layer 31 is also formed to cover the first resin layer 32a. In addition, the second resin layer 32b is formed on the outer surface of the clay layer 31 to completely surround the capacitor element 20. It can be seen that when viewed from the capacitor element 20, the barrier layer 3 has a structure in which the first resin layer 32a, the clay layer 31, and the second resin layer 32b are stacked one on top of each other in the thickness direction defined with respect to the barrier layer 3.

[0103] This capacitor 10 encapsulates the capacitor element 20 with the barrier layer 3 comprising two resin layers 32. Therefore, disposing the clay layer 31 between the two resin layers 32 allows the resin layers 32 to prevent the thin clay layer 31 from being mechanically damaged by external forces, thereby reducing the possibility of causing a decrease in the moisture resistance reliability of the capacitor 10.

[0104] (Fifth embodiment)

[0105] The electronic component 1 according to the fifth embodiment is different from the electronic component 1 according to the first embodiment, the second embodiment, the third embodiment, or the fourth embodiment in the configuration of the barrier layer 3 .

[0106] In the following description, any constituent elements of the present fifth embodiment that have the same function as the corresponding parts in the above-mentioned first embodiment, second embodiment, third embodiment or fourth embodiment will be represented by the same figure marks as the figure marks of the corresponding parts, and their descriptions will be appropriately omitted in this document.

[0107] Note that the configuration described below with respect to the fifth embodiment can be used in combination with the configuration described with respect to the first embodiment, the second embodiment, the third embodiment, or the fourth embodiment (including variations thereof), as appropriate.

[0108] Figure 9 C shows a capacitor 10 as an electronic component 1 according to the fifth embodiment. This capacitor 10 not only includes all the components of the capacitor 10 according to the third embodiment described above, but also includes a second resin layer 32b provided on the outer surface of the second clay layer. That is, the barrier layer 3 includes a first clay layer 31a and a second clay layer 31b as clay layer 31. Furthermore, the barrier layer 3 includes a first resin layer 32a and a second resin layer 32b as resin layer 32. Like the clay layer 31 according to the third embodiment, the first clay layer 31a is formed to surround the capacitor element 20. Similarly, like the resin layer 32 according to the third embodiment, the first resin layer 32a is formed to cover the first clay layer 31a. Furthermore, the second clay layer 31b is formed on the outer surface of the first resin layer 32a to completely surround the capacitor element 20. Furthermore, the second resin layer 32b is formed to cover the second clay layer 31b. It can be seen that barrier layer 3 has a structure in which first clay layer 31 a , first resin layer 32 a , second clay layer 31 b , and second resin layer 32 b are stacked one on another in a thickness direction defined about barrier layer 3 , when viewed from capacitor element 20 .

[0109] This capacitor 10 encapsulates the capacitor element 20 with the barrier layer 3 in which two clay layers 31 and two resin layers 32 are alternately stacked. Therefore, compared with the capacitor 10 according to the first embodiment including the single clay layer 31, this capacitor 10 further reduces the possibility of water passing through the barrier layer 3. In addition, this capacitor 10 also enables the two resin layers 32 to protect the two clay layers, thereby further reducing the possibility of causing a decrease in the moisture resistance reliability of the capacitor 10.

[0110] (Summary)

[0111] The electronic component ( 1 ) according to the exemplary embodiment described above is a specific embodiment of the following aspects of the present disclosure.

[0112] An electronic component (1) according to a first aspect includes: an electronic component element (2); and a barrier layer (3) encapsulating the electronic component element (2). The barrier layer (3) includes a clay layer (31) containing clay. The clay layer (31) is provided to surround the electronic component element (2).

[0113] This aspect can reduce the penetration of water and gas from outside the electronic component element (2) into the electronic component element (2) using the clay layer (31), thereby achieving the advantage of providing such an electronic component whose performance is hardly affected by changes in its electrostatic capacitance caused by, for example, moisture absorption.

[0114] In the electronic component (1) according to the second aspect (which can be implemented in combination with the first aspect), the barrier layer (3) includes a resin layer (32) containing a resin. The clay layer (31) and the resin layer (32) are stacked on each other.

[0115] According to this aspect, a clay layer (31) having excellent barrier capability and a resin layer (32) having high mechanical strength are stacked on each other, which can reduce damage to the clay layer (31) caused by external force, thereby achieving the advantage of forming a barrier layer (3) with high moisture resistance reliability.

[0116] In the electronic component (1) according to the third aspect (which can be implemented in combination with the second aspect), the resin layer (32) is thicker than the clay layer (31).

[0117] Generally, the clay layer (31) exhibits excellent moisture permeation resistance even when formed into a thin layer, but it is so hard and brittle that it is easily damaged after external force such as impact is applied thereto. In addition, it is difficult to form a thick clay layer (31) from the perspective of productivity. On the other hand, the resin layer (32) has lower moisture permeation resistance than the clay layer (31), but can be easily formed to be thick enough to absorb external force such as impact. Therefore, according to this aspect, a thick resin layer (32) is stacked on the clay layer (31) to support the clay layer (31), which makes it possible to achieve the advantage of effectively reducing mechanical damage to the clay layer (31).

[0118] In the electronic component (1) according to the fourth aspect (which can be implemented in combination with the second aspect or the third aspect), the clay layer (31) is closer to the electronic component element (2) than the resin layer (32).

[0119] This aspect enables the resin layer (32) to prevent the thin clay layer (31) from being mechanically damaged by external force, thereby achieving the advantage of providing an electronic component (1) having high moisture resistance reliability.

[0120] In the electronic component (1) according to the fifth aspect (which can be implemented in combination with the second aspect or the third aspect), the resin layer (32) is closer to the electronic component element (2) than the clay layer (31).

[0121] According to this aspect, providing the clay layer (31) enables the thickness of the resin layer (32) to be reduced, thereby achieving the advantage of enabling miniaturization. From the perspective of ensuring moisture resistance and versatility in shape, film-type capacitors are generally resin-molded. This aspect achieves the advantage of forming the clay layer (31) in an additional process step without changing the known structure or manufacturing process.

[0122] In the electronic component (1) according to the sixth aspect (which can be implemented in combination with any one of the first to fifth aspects), the clay layer (31) contains mineral particles (311) and a binder (312). The mineral particles (311) include plate-like particles or flake-like particles.

[0123] This aspect achieves the advantage of enabling the formation of a clay layer (31) having excellent resistance to moisture permeation using mineral particles (311) having a high aspect ratio.

[0124] In the electronic component (1) according to the seventh aspect (which can be implemented in combination with the sixth aspect), the mineral particles (311) include at least one selected from the group consisting of: mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite and nontronite.

[0125] This aspect achieves an advantage of enabling formation of a clay layer having excellent resistance to moisture permeation.

[0126] In the electronic component (1) according to the eighth aspect (which can be implemented in combination with the sixth aspect or the seventh aspect), the adhesive (312) includes at least one selected from the group consisting of: polypropylene, polyethylene sulfide, polyimide, polyamide, polyethylene terephthalate, epoxy resin, fluororesin, polyester resin, polyurethane resin, acrylic resin, phenoxy resin, polyacetal and polyvinyl alcohol.

[0127] This aspect achieves the advantage of enabling the formation of a clay layer (31) having excellent resistance to moisture permeation by filling the gaps between the mineral particles (311) with the binder (312).

[0128] In the electronic component (1) according to the ninth aspect (which can be implemented in combination with any one of the first to eighth aspects), the content of the mineral particles (311) in the clay layer (31) is equal to or greater than 50% by mass relative to the total mass of the clay layer (31).

[0129] This aspect achieves the advantage of enabling formation of a clay layer (31) having excellent resistance to moisture permeation.

[0130] In the electronic component (1) according to the tenth aspect (which can be implemented in combination with any one of the first to ninth aspects), the clay layer (31) completely covers the outer surface of the electronic component element (2) except for a part of the external electrode (21) of the electronic component element (2).

[0131] This aspect achieves the advantage of reducing the possibility that the clay layer (31) will reduce the moisture resistance reliability of the barrier layer (3).

[0132] In the capacitor (10) according to the eleventh aspect, the electronic component (1) according to any one of the first to tenth aspects includes a capacitor element (20) as its electronic component element (2).

[0133] This aspect achieves the advantage of providing a capacitor (10) whose electrostatic capacitance hardly changes due to moisture permeation.

[0134] In the capacitor (10) according to the twelfth aspect (which can be implemented in combination with the eleventh aspect), the capacitor element (20) includes a pair of metallized films (24), in each of which an electrode film (23) is formed on a dielectric film (22). The pair of metallized films (24) are wound into a roll so that the electrode films (23) face each other, while the dielectric film (22) is interposed between the electrode films (23).

[0135] Generally, when absorbing moisture, a film-type capacitor may have reduced electrostatic capacitance due to oxidation of the energized Al electrode. On the other hand, this aspect achieves an advantage of reducing the possibility of causing a decrease in electrostatic capacitance.

[0136] List of Reference Numerals

[0137] 1 Electronic components

[0138] 10 capacitors

[0139] 2Electronic components

[0140] 20 capacitor elements

[0141] 21 External electrodes

[0142] 22 Dielectric Film

[0143] 23 Electrode membrane

[0144] 24 Metallized Film

[0145] 3 barrier layer

[0146] 31 Clay layer

[0147] 311 mineral particles

[0148] 312 adhesive

[0149] 32 resin layers.

Claims

1. An electronic component, comprising: Electronic components; and a barrier layer encapsulating the electronic component element, The barrier layer comprises a clay layer containing clay, The barrier layer includes a resin layer containing a resin, The clay layer and the resin layer are stacked on each other, The clay layer is closer to the electronic component element than the resin layer, The clay layer is a coating film formed by supplying a treatment liquid containing mineral particles and a binder onto the outer surface of the electronic component element. The clay layer is provided to surround the electronic component element.

2. The electronic component according to claim 1, wherein The resin layer is thicker than the clay layer.

3. The electronic component according to claim 1 or 2, wherein The mineral particles include plate-like particles or flake-like particles.

4. The electronic component according to claim 1 or 2, wherein The mineral particles include at least one selected from the group consisting of mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite, and nontronite.

5. The electronic component according to claim 1 or 2, wherein The binder includes at least one selected from the group consisting of polypropylene, polyethylene sulfide, polyimide, polyamide, polyethylene terephthalate, epoxy resin, fluororesin, polyester resin, polyurethane resin, acrylic resin, phenoxy resin, polyacetal, and polyvinyl alcohol.

6. The electronic component according to claim 1 or 2, wherein The content of the mineral particles in the clay layer is equal to or greater than 50% by mass relative to the total mass of the clay layer.

7. The electronic component according to claim 1 or 2, wherein The barrier layer is configured to completely cover the electronic component element except for a portion through which the external connection terminal extends. 8 . A capacitor comprising a capacitor element as the electronic component element of the electronic component according to claim 1 .

9. The capacitor of claim 8, wherein The capacitor element includes a pair of metallized films, in each of which an electrode film is formed on a dielectric film, and The pair of metallized films are wound into a roll so that the electrode films face each other with the dielectric film interposed between the electrode films.

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