Laminated film capacitor and method for manufacturing same

Abstract

The technical problem is to provide a laminated film capacitor which has high rigidity and is not easy to warp. [Solution] A laminated film capacitor (100) is provided with: film capacitors (10A, 10B); a resin layer (51) that is positioned between the thin-film capacitor (10A) and the thin-film capacitor (10B) and contains a glass cloth (51G); a terminal electrode (61) connected to the upper electrodes (30A, 30B); and a terminal electrode 62 connected to the lower electrodes 20A, 20B. As a result, it is possible to provide a laminated film capacitor having high rigidity.

Description

Technical Field

[0001] The present disclosure relates to a stacked thin film capacitor and a method for manufacturing the same. Background Art

[0002] Patent Document 1 discloses a multilayer film capacitor formed by stacking a plurality of film capacitors. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-140312 Summary of the Invention Technical problem to be solved by the invention

[0004] Since the thickness of the laminated film capacitor is thin as a whole, there is a technical problem that the rigidity is insufficient and warping is easily caused.

[0005] In this disclosure, a technology for improving the rigidity of a multilayer film capacitor and suppressing the occurrence of warping is described. Technical means for solving technical problems

[0006] A stacked thin-film capacitor according to one aspect of the present disclosure includes: a first thin-film capacitor including a first lower electrode, a first upper electrode, and a first dielectric layer positioned between the first lower electrode and the first upper electrode; a second thin-film capacitor including a second lower electrode, a second upper electrode, and a second dielectric layer positioned between the second lower electrode and the second upper electrode; a first resin layer comprising glass cloth positioned between the first thin-film capacitor and the second thin-film capacitor; a first terminal electrode formed on a first side surface of the first resin layer, connected to the first upper electrode and to one of the second upper electrode and the second lower electrode; and a second terminal electrode formed on a second side surface of the first resin layer, connected to the first lower electrode and to the other of the second upper electrode and the second lower electrode.

[0007] A method for manufacturing a stacked thin-film capacitor according to one aspect of the present disclosure includes: a first step of forming a first thin-film capacitor sheet and a second thin-film capacitor sheet by sequentially forming a dielectric layer and an upper electrode on a lower electrode, separating the upper electrode into a plurality of sheets by patterning the upper electrode, and separating the lower electrode into a plurality of sheets by patterning the lower electrode; a second step of forming a stacked thin-film capacitor sheet by stacking the first and second thin-film capacitor sheets with a first resin layer including glass cloth interposed therebetween; a third step of singulating the stacked thin-film capacitor sheet into a plurality of stacked thin-film capacitors by dividing the stacked thin-film capacitor sheet; and a fourth step of forming a first terminal electrode on a first side surface of the first resin layer, the first terminal electrode being connected to the upper electrode included in the first thin-film capacitor sheet and to one of the upper electrode and the lower electrode included in the second thin-film capacitor sheet, and forming a second terminal electrode on a second side surface of the first resin layer, the second terminal electrode being connected to the lower electrode included in the first thin-film capacitor sheet and to the other of the upper electrode and the lower electrode included in the second thin-film capacitor sheet. Effects of the Invention

[0008] According to the present disclosure, it is possible to provide a technology for improving the rigidity of a multilayer film capacitor and suppressing the occurrence of warping. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 1 is a schematic cross-sectional view for explaining the structure of a multilayer film capacitor 100 according to the first embodiment of the disclosed technology. Figure 2 It is a process diagram for explaining the method of manufacturing the multilayer film capacitor 100 . Figure 3 It is a process diagram for explaining the method of manufacturing the multilayer film capacitor 100 . Figure 4 It is a process diagram for explaining the method of manufacturing the multilayer film capacitor 100 . Figure 5 It is a process diagram for explaining the method of manufacturing the multilayer film capacitor 100 . Figure 6 It is a process diagram for explaining the method of manufacturing the multilayer film capacitor 100 . Figure 7 It is a process diagram for explaining the method of manufacturing the multilayer film capacitor 100 . Figure 8 It is a process diagram for explaining the method of manufacturing the multilayer film capacitor 100 . Figure 9 It is a process diagram for explaining the method of manufacturing the multilayer film capacitor 100 . Figure 10It is a process diagram for explaining the method of manufacturing the multilayer film capacitor 100 . Figure 11 1 is a schematic cross-sectional view for explaining the structure of a multilayer film capacitor 200 according to a second embodiment of the presently disclosed technology. DETAILED DESCRIPTION

[0010] Hereinafter, embodiments of the technology of the present disclosure will be described in detail with reference to the drawings.

[0011] Figure 1 1 is a schematic cross-sectional view for explaining the structure of a multilayer film capacitor 100 according to the first embodiment of the disclosed technology.

[0012] like Figure 1 As shown, the multilayer film capacitor 100 of the first embodiment includes two stacked film capacitors 10A and 10B, resin layers 51 to 53 in which the film capacitors 10A and 10B are embedded, and terminal electrodes 61 and 62 provided on side surfaces of the resin layers 51 to 53 .

[0013] Thin film capacitor 10A and thin film capacitor 10B have the same structure. Thin film capacitor 10A includes a lower electrode 20A, an upper electrode 30A, and a dielectric layer 11A located therebetween. Similarly, thin film capacitor 10B includes a lower electrode 20B, an upper electrode 30B, and a dielectric layer 11B located therebetween. Lower electrode 20A includes an electrode layer 21A made of Ni or the like, which is in contact with dielectric layer 11A, and an electrode layer 22A made of Cu or the like, which covers electrode layer 21A. Similarly, lower electrode 20B includes an electrode layer 21B made of Ni or the like, which is in contact with dielectric layer 11B, and an electrode layer 22B made of Cu or the like, which covers electrode layer 21B. Upper electrode 30A includes an electrode layer 31A made of Ni or the like, which is in contact with dielectric layer 11A, and an electrode layer 32A made of Cu or the like, which covers electrode layer 31A. Similarly, the upper electrode 30B includes an electrode layer 31B made of Ni or the like in contact with the dielectric layer 11B, and an electrode layer 32B made of Cu or the like covering the electrode layer 31B.

[0014] The dielectric layers 11A and 11B are made of, for example, a perovskite-based dielectric material. Examples of perovskite-based dielectric materials include BaTiO3 (barium titanate), (Ba 1-X Sr X )TiO3(barium strontium titanate), (Ba 1-X Ca X )TiO3, PbTiO3, Pb(Zr X Ti 1-X )O3、(Sr 1-X Ca X )(Ti1-Y Zr Y )O3、Ba(Mg 1 / 3 Ta 2 / 3 )O3 and other ferroelectric materials or paraelectric materials with perovskite structure; Pb(Mg 1 / 3 Nb 2 / 3 )O3 and other composite perovskite relaxor ferroelectric materials; Bi4Ti3O 12 、SrBi2Ta2O9 etc. are bismuth layered compounds; (Sr 1-X Ba X )Tungsten bronze type ferroelectric materials represented by Nb2O6, PbNb2O6, etc. Here, in the perovskite structure, perovskite type relaxor ferroelectric materials, bismuth layered compounds, and tungsten bronze type ferroelectric materials, the ratio of the A site to the B site is usually an integer ratio, but in order to improve the characteristics, it can also be intentionally deviated from the integer ratio. In addition, in order to control the characteristics of the dielectric layers 11A and 11B, the dielectric layers 11A and 11B can appropriately contain additives as auxiliary components. The relative dielectric constant (ε r ) is, for example, 10 or greater. Furthermore, the dielectric strength of dielectric layers 11A and 11B is preferably as high as possible, with no particular upper limit. Furthermore, the relative permittivity of dielectric layers 11A and 11B is preferably as high as possible, with no particular upper limit. The thickness of dielectric layers 11A and 11B is, for example, approximately 10 nm to 6000 nm.

[0015] Connecting electrode 40A, composed of electrode layers 41A and 42A, is provided in the same layer as upper electrode 30A. Connecting electrode 40A is connected to lower electrode 20A via through-hole 12A provided in dielectric layer 11A. Similarly, connecting electrode 40B, composed of electrode layers 41B and 42B, is provided in the same layer as upper electrode 30B. Connecting electrode 40B is connected to lower electrode 20B via through-hole 12B provided in dielectric layer 11B.

[0016] In the stacked thin-film capacitor 100 of this embodiment, thin-film capacitors 10A and 10B are stacked so that lower electrode 20A of thin-film capacitor 10A faces lower electrode 20B of thin-film capacitor 10B. Furthermore, upper electrode 30A of thin-film capacitor 10A and upper electrode 30B of thin-film capacitor 10B are connected to a common terminal electrode 61. Meanwhile, connecting electrode 40A of thin-film capacitor 10A and connecting electrode 40B of thin-film capacitor 10B are connected to a common terminal electrode 62. Thus, thin-film capacitors 10A and 10B are connected in parallel between terminal electrodes 61 and 62.

[0017] Resin layers 51-53 serve as protective members that embed film capacitors 10A and 10B. Resin layer 51 is located between film capacitors 10A and 10B, resin layer 52 covers upper electrode 30A of film capacitor 10A, and resin layer 53 covers upper electrode 30B of film capacitor 10B. Resin layers 51-53 contain glass cloths 51G to 53G, respectively, which significantly improves the rigidity of laminated film capacitor 100 and suppresses warping.

[0018] The content of glass cloth 51G to 53G in the resin layers 51 to 53 is preferably 30% to 75% by volume. This is because if the content of glass cloth 51G to 53G exceeds 75% by volume, adhesion to film capacitors 10A and 10B may be insufficient. If the content of glass cloth 51G to 53G is less than 30% by volume, the shape of the laminated film capacitor 100 cannot be maintained due to insufficient rigidity, and warping may occur. To ensure sufficient adhesion to film capacitors 10A and 10B and sufficient rigidity of the laminated film capacitor 100, the content of glass cloth 51G to 53G in the resin layers 51 to 53 is more preferably 40% to 70% by volume. Furthermore, by positioning the glass cloth 51G to 53G in the resin layers 51 to 53 closer to the center in the thickness direction, the symmetry of the resin layers 51 to 53 in the thickness direction can be improved, thereby suppressing warping of the laminated film capacitor 100.

[0019] As described above, in the stacked film capacitor 100 of this embodiment, the two film capacitors 10A and 10B are not only stacked with a resin layer interposed therebetween, but also include glass cloth 51G in the resin layer 51 located between the film capacitors 10A and 10B. This significantly improves overall rigidity. Furthermore, in this embodiment, the film capacitors 10A and 10B are stacked so that the lower electrode 20A of the film capacitor 10A faces the lower electrode 20B of the film capacitor 10B. This results in high vertical symmetry and reduces the risk of warping.

[0020] Next, a method for manufacturing the multilayer film capacitor 100 according to this embodiment will be described.

[0021] Figures 2 to 10 These are process diagrams for explaining the method for manufacturing the multilayer film capacitor 100 according to the present embodiment.

[0022] First, a dielectric layer 11 ( Figure 2The lower electrode 20 has a structure in which an electrode layer 21 made of Ni or the like and an electrode layer 22 made of Cu or the like are stacked, and a dielectric layer 11 is formed on the surface of the electrode layer 21. Then, a plurality of through holes 12 are formed in the dielectric layer 11 by patterning the dielectric layer 11 ( Figure 3 ), an upper electrode 30 is formed on the surface of the dielectric layer 11 ( Figure 4 The upper electrode 30 has a structure in which an electrode layer 31 made of Ni or the like and an electrode layer 32 made of Cu or the like are stacked. The electrode layer 31 is formed on the surface of the dielectric layer 11. As a result, the through hole 12 is filled with the electrode layer 31, and the lower electrode 20 and the upper electrode 30 are connected via the through hole 12.

[0023] Next, the upper electrode 30 is patterned to form the slits 33 ( Figure 5 ). Thus, the upper electrode 30 is separated into a plurality of parts. Next, a resin layer 50 (containing glass cloth 50G) is formed so as to cover the patterned upper electrode 30. Figure 6 ). Thus, the slit 33 is filled with the resin layer 50. Next, the lower electrode 20 is patterned to form the slit 23 ( Figure 7 ). Thus, the lower electrode 20 is separated into a plurality of parts. The film capacitor sheet 10 is completed through the above steps.

[0024] A plurality of such film capacitor sheets 10 are prepared, and two film capacitor sheets 10 are stacked with a resin layer 51 including a glass cloth 51G interposed therebetween. Figure 8 Here, two thin film capacitor sheets 10 are stacked in such a manner that the lower electrodes 20 included in the two thin film capacitor sheets 10 face each other. Thus, a stacked thin film capacitor sheet S ( Figure 9 Then, the multilayer film capacitor sheet S is divided along the dotted line L overlapping the slit 23 to separate the multilayer film capacitors 100 ( Figure 10 ).

[0025] Thus, the portion included in one film capacitor sheet 10 becomes film capacitor 10A, and the portion included in the other film capacitor sheet 10 becomes film capacitor 10B. In addition, the resin layer 50 covering one film capacitor sheet 10 becomes resin layer 52, and the resin layer 50 covering the other film capacitor sheet 10 becomes resin layer 53. Furthermore, the upper electrode 30 and the connecting electrode 40 are separated by the slit 33. Then, if the terminal electrodes 61 and 62 are formed on the side surfaces of the resin layers 51 to 53, the Figure 1 The stacked film capacitor 100 is shown.

[0026] In this manner, after the laminated film capacitor sheet S is produced by laminating two film capacitor sheets 10 with the resin layer 51 including the glass cloth 51G interposed therebetween, the laminated film capacitor sheet S is divided into individual pieces, thereby obtaining a plurality of laminated film capacitors 100 .

[0027] Figure 11 1 is a schematic cross-sectional view for explaining the structure of a multilayer film capacitor 200 according to a second embodiment of the presently disclosed technology.

[0028] like Figure 11 As shown, the multilayer film capacitor 200 of the second embodiment differs from the multilayer film capacitor 100 of the first embodiment in that the upper and lower surfaces of the film capacitor 10A of the former are reversed. The rest of the basic structure is the same as that of the multilayer film capacitor 100 of the first embodiment. Therefore, the same reference numerals are used to designate the same elements, and duplicate descriptions are omitted.

[0029] In the stacked film capacitor 200 of this embodiment, film capacitors 10A and 10B are stacked so that the upper electrode 30A of film capacitor 10A faces the lower electrode 20B of film capacitor 10B. Because the upper electrode 30A of film capacitor 10A and the lower electrode 20B of film capacitor 10B are connected to different terminal electrodes, sufficient insulation must be ensured between them. However, in the stacked film capacitor 200 of this embodiment, glass cloth 51G is interposed between them, ensuring sufficient insulation properties. Furthermore, in this embodiment, since the vertical orientation of the plurality of film capacitors 10A and 10B is the same, the manufacturing process does not become complicated even when stacking three or more film capacitors.

[0030] As described above, the embodiments of the technology disclosed herein have been described. However, the technology disclosed herein is not limited to the above embodiments, and various modifications can be made without departing from the spirit and scope thereof, which are naturally included in the scope of the technology disclosed herein.

[0031] For example, in the first and second embodiments, the upper electrodes 30A and 30B are connected to the terminal electrode 61, and the lower electrodes 20A and 20B are connected to the terminal electrode 62. However, the connection relationship between the thin-film capacitors 10A and 10B and the terminal electrodes 61 and 62 is not limited to this. Therefore, the upper electrode 30A and the lower electrode 20B may be connected to the terminal electrode 61, and the upper electrode 30B and the lower electrode 20A may be connected to the terminal electrode 62.

[0032] Furthermore, the multilayer film capacitors 100 and 200 shown in the first and second embodiments have a structure in which two film capacitors 10A and 10B are stacked. However, by stacking three or more film capacitors, a multilayer film capacitor with a higher capacitance can be formed.

[0033] The technology disclosed herein includes, but is not limited to, the following structural examples.

[0034] A stacked thin-film capacitor according to one aspect of the present disclosure includes: a first thin-film capacitor including a first lower electrode, a first upper electrode, and a first dielectric layer positioned between the first lower electrode and the first upper electrode; a second thin-film capacitor including a second lower electrode, a second upper electrode, and a second dielectric layer positioned between the second lower electrode and the second upper electrode; a first resin layer comprising glass cloth positioned between the first thin-film capacitor and the second thin-film capacitor; a first terminal electrode formed on a first side surface of the first resin layer, connected to the first upper electrode and to one of the second upper electrode and the second lower electrode; and a second terminal electrode formed on a second side surface of the first resin layer, connected to the first lower electrode and to the other of the second upper electrode and the second lower electrode.

[0035] The above-mentioned laminated film capacitor may further include: a second resin layer comprising glass cloth, with the first film capacitor sandwiched between the second and first resin layers; and a third resin layer comprising glass cloth, with the second film capacitor sandwiched between the third and first resin layers. This can provide a laminated film capacitor with even higher rigidity.

[0036] In the above-mentioned multilayer thin film capacitor, the first terminal electrode may be connected to the first upper electrode and the second upper electrode, and the second terminal electrode may be connected to the first lower electrode and the second lower electrode.

[0037] In the aforementioned stacked film capacitor, the first and second film capacitors may be stacked with the first upper electrode and the second lower electrode facing each other via the first resin layer. Even in this case, the presence of the glass cloth ensures sufficient insulation between the first upper electrode and the second lower electrode.

[0038] A method for manufacturing a stacked thin-film capacitor according to one aspect of the present disclosure includes the following steps: a first step of forming a first thin-film capacitor sheet and a second thin-film capacitor sheet by sequentially forming a dielectric layer and an upper electrode on a lower electrode, patterning the upper electrode to separate the upper electrode into a plurality of sheets, and patterning the lower electrode to separate the lower electrode into a plurality of sheets; a second step of forming a stacked thin-film capacitor sheet by stacking the first and second thin-film capacitor sheets with a first resin layer containing glass cloth interposed therebetween; a third step of singulating the stacked thin-film capacitor sheet into a plurality of stacked thin-film capacitors by dividing the stacked thin-film capacitor sheet; and a fourth step of forming a first terminal electrode on a first side surface of the first resin layer, the first terminal electrode being connected to the upper electrode included in the first thin-film capacitor sheet and to one of the upper and lower electrodes included in the second thin-film capacitor sheet, and forming a second terminal electrode on a second side surface of the first resin layer, the second terminal electrode being connected to the lower electrode included in the first thin-film capacitor sheet and to the other of the upper and lower electrodes included in the second thin-film capacitor sheet. This method can produce a plurality of stacked thin-film capacitors with high rigidity.

[0039] In the above-described method for manufacturing a multilayer film capacitor, the first step may further include covering the patterned upper electrode with a second resin layer comprising glass cloth, and in the second step, the first and second film capacitor sheets may be stacked such that the lower electrodes included in the first and second film capacitor sheets face each other. This allows for the manufacture of a multilayer film capacitor with high top-to-bottom symmetry. Description of Reference Signs

[0040] 10 film capacitor sheets 10A, 10B film capacitors 11, 11A, 11B dielectric layers 12, 12A, 12B through holes 20, 20A, 20B lower electrodes 21, 21A, 21B, 22, 22A, 22B electrode layers 23 slits 30, 30A, 30B upper electrodes 31, 31A, 31B, 32, 32A, 32B electrode layers 33 slits 40, 40A, 40B connecting electrodes 41A, 41B, 42A, 42B electrode layers 50~53 resin layers 50G~53G glass cloth 61, 62 terminal electrodes 62-terminal electrode 100, 200 layer film capacitors S-layer film capacitor sheet.

Claims

1. A laminated film capacitor, wherein: The stacked film capacitor is formed by stacking a plurality of film capacitors, wherein the plurality of film capacitors include at least a first film capacitor and a second film capacitor. The stacked film capacitor comprises: The first thin film capacitor includes a first lower electrode, a first upper electrode, and a first dielectric layer located between the first lower electrode and the first upper electrode; the second thin film capacitor comprising a second lower electrode, a second upper electrode, and a second dielectric layer located between the second lower electrode and the second upper electrode; a first resin layer comprising glass cloth, located between the first film capacitor and the second film capacitor; a first terminal electrode formed on a first side surface of the first resin layer, connected to the first upper electrode and connected to one of the second upper electrode and the second lower electrode; and A second terminal electrode is formed on a second side surface of the first resin layer, is connected to the first lower electrode, and is connected to the other of the second upper electrode and the second lower electrode.

2. The multilayer film capacitor according to claim 1, wherein Also features: a second resin layer including glass cloth, the first film capacitor being sandwiched between the second resin layer and the first resin layer; and A third resin layer including glass cloth, wherein the second film capacitor is sandwiched between the third resin layer and the first resin layer.

3. The multilayer film capacitor according to claim 1 or 2, wherein: The first terminal electrode is connected to the first upper electrode and the second upper electrode, The second terminal electrode is connected to the first lower electrode and the second lower electrode.

4. The multilayer film capacitor according to claim 3, wherein The first thin film capacitor and the second thin film capacitor are stacked with the first resin layer interposed therebetween such that the first upper electrode and the second lower electrode face each other.

5. A method for manufacturing a laminated film capacitor, wherein: have: A first step of forming a first thin film capacitor sheet and a second thin film capacitor sheet by sequentially forming a dielectric layer and an upper electrode on a lower electrode, patterning the upper electrode to separate the upper electrode into a plurality of sheets, and patterning the lower electrode to separate the lower electrode into a plurality of sheets. a second step of forming a laminated film capacitor sheet by laminating the first film capacitor sheet and the second film capacitor sheet via a first resin layer containing glass cloth; A third step is to separate the stacked film capacitor sheet into a plurality of stacked film capacitors; and In a fourth step, a first terminal electrode is formed on a first side surface of the first resin layer, the first terminal electrode being connected to the upper electrode included in the first thin-film capacitor sheet and to one of the upper electrode and the lower electrode included in the second thin-film capacitor sheet, and a second terminal electrode is formed on a second side surface of the first resin layer, the second terminal electrode being connected to the lower electrode included in the first thin-film capacitor sheet and to the other of the upper electrode and the lower electrode included in the second thin-film capacitor sheet.

6. The method for manufacturing a multilayer film capacitor according to claim 5, wherein: The first step further includes: covering the patterned upper electrode with a second resin layer containing glass cloth, In the second step, the first thin film capacitor sheet and the second thin film capacitor sheet are stacked such that the lower electrode included in the first thin film capacitor sheet and the lower electrode included in the second thin film capacitor sheet face each other.

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