Capacitor

Abstract

A capacitor (10) is provided with: a conductive substrate (20); a dielectric (31) disposed on the upper surface (201) of the substrate (20); an electrode (41) disposed on the upper surface of the dielectric (31) and facing the substrate (20) with the dielectric (31) therebetween; a terminal electrode for external connection disposed on the upper surface of the electrode (41) and electrically connected to the electrode (41); and an insulating film (60) on a part of the substrate (20) and a part of the terminal electrode other than the external connection part. Td is the thickness of the dielectric (31), Tsr is the distance between the portion of the connection terminal electrode not covered by the insulating film (60) and the portion of the substrate (20) not covered by the insulating film (60) along the surface of the insulating film (60), and the thickness Td and the distance Tsr satisfy Tsrlt; and the relation is 18 * Td2.

Description

Technical Field

[0001] The present invention relates to capacitors formed using thin film technology. Background Art

[0002] Patent Document 1 describes a composite electronic component including a capacitor and an ESD protection element.

[0003] In Patent Document 1, an ESD protection element includes a pair of discharge electrodes facing each other with a gap therebetween and an electrostatic absorption layer disposed between the pair of discharge electrodes. The electrostatic absorption layer is a composite body of a sea-island structure in which island-shaped conductive inorganic materials are dispersed planarly and discontinuously in a dielectric layer.

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-23247 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] However, in the composite electronic component of Patent Document 1, the discharge mechanism is formed inside the component, and the shape becomes complicated.

[0009] Therefore, the present invention aims to provide a capacitor having an ESD protection function with a simple structure.

[0010] Technical solutions to solve problems

[0011] The capacitor of the present invention comprises: a lower electrode; a dielectric disposed on the upper surface of the lower electrode; an upper electrode disposed on the upper surface of the dielectric and opposed to the lower electrode with the dielectric sandwiched therebetween; a terminal electrode for external connection disposed on the upper surface of the upper electrode and electrically connected to the upper electrode; and an insulating film covering the upper electrode, the dielectric, a portion of the terminal electrode other than the external connection portion, and a portion of the lower electrode.

[0012] The thickness of the dielectric is set to Td, and the distance along the surface of the insulating film between the portion of the connecting terminal electrode not covered by the insulating film and the portion of the lower electrode not covered by the insulating film is set to Tsr. The thickness Td and the distance Tsr satisfy Tsr<18×Td 2 relationship.

[0013] In this structure, if static electricity is applied to the terminal electrode, the charge caused by the static electricity flows from the terminal electrode to the lower electrode through gas discharge along the outer surface of the insulating film, and is discharged from the lower electrode to the ground through another terminal electrode. As a result, the charge caused by the static electricity can be suppressed from being applied to the dielectric between the upper electrode and the lower electrode, and the dielectric breakdown can be suppressed. In this way, in this structure, the dielectric breakdown can be suppressed without separately providing a functional element for discharge.

[0014] Effects of the Invention

[0015] According to the present invention, a capacitor having an ESD protection function can be realized with a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 (A) is a top view of a capacitor according to a first embodiment of the present invention. Figure 1 (B) shows Figure 1 (A) is a diagram of the AB cross section shown.

[0017] Figure 2 This is an enlarged cross-sectional view of the vicinity of the side surface of the capacitor and the vicinity of the side surface of the terminal electrode according to the first embodiment of the present invention.

[0018] Figure 3 It is a side cross-sectional view showing a discharge state of static electricity in the capacitor according to the first embodiment.

[0019] Figure 4 It is a graph showing the relationship between the dielectric breakdown of a dielectric constituting a capacitor, the thickness Td, and the shortest distance Tsr.

[0020] Figure 5 (A) Figure 5 (B) Figure 5 (C) Figure 5 (D) Figure 5 (E) is a cross-sectional view showing the structure of the capacitor in each manufacturing step according to the first embodiment of the present invention.

[0021] Figure 6 (A) Figure 6 (B) Figure 6 (C) Figure 6 (D) is a cross-sectional view showing the structure of the capacitor in each manufacturing step according to the first embodiment of the present invention.

[0022] Figure 7 (A) is a plan view of a capacitor according to a second embodiment of the present invention. Figure 7 (B) shows Figure 7 (A) is a diagram of the AB cross section shown.

[0023] Figure 8 This is an enlarged cross-sectional view of the vicinity of the side surface of the capacitor and the vicinity of the side surface of the terminal electrode according to the second embodiment of the present invention.

[0024] Fig. 9 This is an enlarged cross-sectional view of the vicinity of the side surface of the capacitor and the vicinity of the side surface of the terminal electrode according to the third embodiment of the present invention.

[0025] Fig.10 (A) is a top view of a capacitor according to a fourth embodiment of the present invention. Fig.10 (B) shows Fig.10 (A) is a diagram of the AB cross section shown.

[0026] Fig.11 It is a diagram showing a cross section of a capacitor according to a fifth embodiment of the present invention.

[0027] Fig.12 It is a diagram showing a cross section of a capacitor according to a sixth embodiment of the present invention.

[0028] Fig.13 It is a diagram showing a cross section of a capacitor according to a seventh embodiment of the present invention. DETAILED DESCRIPTION

[0029] [First embodiment]

[0030] A capacitor according to a first embodiment of the present invention will be described with reference to the drawings. Figure 1 (A) is a top view of a capacitor according to a first embodiment of the present invention. Figure 1 (B) shows Figure 1 (A) is a diagram of the AB cross section shown. Figure 2 This is an enlarged cross-sectional view of the side surface of the capacitor and the side surface of the terminal electrode according to the first embodiment of the present invention. Figure 1 (A) Figure 1 (B) Figure 2 The drawings showing the structures of the embodiments of the present invention are exaggerated in size, and in particular, the size in the z-axis direction is exaggerated.

[0031] (Structure of capacitor 10)

[0032] like Figure 1 (A) Figure 1 (B) Figure 2As shown, the capacitor 10 includes a substrate 20 , a dielectric 31 , a dielectric 32 , an electrode 41 , an electrode 42 , a protective film 50 , an insulating film 60 , a base electrode 71 for a terminal electrode, a base electrode 72 for a terminal electrode, an external connection electrode 81 , and an external connection electrode 82 .

[0033] The substrate 20 is a flat plate having an upper surface 201 and a lower surface 202. The thickness of the substrate 20 is, for example, about 150 μm. The substrate 20 is a conductive semiconductor, for example, including Si. The resistivity of the substrate 20 is, for example, 10 mΩ·cm, or may be about 1Ω·cm. The substrate 20 corresponds to an example of the “lower electrode” of the present invention.

[0034] The dielectric 31 and the dielectric 32 are arranged on the upper surface 201 of the substrate 20. The dielectric 31 and the dielectric 32 are, for example, flat films and are rectangular in a top view (viewed in a direction parallel to the z-axis direction). The dielectric 31 and the dielectric 32 are arranged separately on the upper surface 201. For example, Figure 1 As shown in FIG. 2B , the dielectric 31 and the dielectric 32 are arranged to be separated from each other in the x-axis direction of the substrate 20 .

[0035] The thickness of the dielectric 31 and the dielectric 32 is, for example, 1.0 μm. The dielectric 31 and the dielectric 32 include, for example, SiO 2. The thickness and material of the dielectric 31 and the thickness and material of the dielectric 32 may be different, but the thickness and material of the dielectric 31 and the thickness and material of the dielectric 32 are the same, so that the manufacturing becomes easy, and the height of the external connection electrode 81 and the external connection electrode 82 are consistent, so that the installation becomes easy.

[0036] The electrode 41 is arranged on the upper surface of the dielectric 31. More specifically, the electrode 41 is arranged on the surface of the dielectric 31 that faces the surface that contacts the substrate 20. That is, the electrode 41 and the substrate 20 are arranged with the dielectric 31 interposed therebetween.

[0037] In this way, the structure in which the dielectric 31 is sandwiched between the electrode 41 and the conductive substrate 20 generates capacitance, and the capacitance is determined by the facing area of ​​the electrode 41 and the substrate 20 , the dielectric constant of the dielectric 31 , and the thickness of the dielectric 31 .

[0038] The thickness of the electrode 41 is, for example, 1.0 μm. The electrode 41 includes, for example, Al.

[0039] The electrode 42 covers the dielectric 32 and the substrate 20. Specifically, the electrode 42 is disposed on the upper surface and each side surface of the dielectric 32, and is electrically and physically connected to the substrate 20. The electrode 42 is not directly physically connected to the electrode 41. The thickness of the electrode 42 is, for example, 1.0 μm. The electrode 42 includes, for example, Al.

[0040] The protective film 50 is disposed on the upper surface side of the substrate 20. The protective film 50 covers the upper surface 201 of the substrate 20, the dielectric 31, the electrode 41, and the electrode 42. At this time, the protective film 50 has a recessed portion 501 that exposes a portion of the upper surface of the electrode 41 and a recessed portion 502 that exposes a portion of the upper surface of the electrode 42.

[0041] The thickness of the protective film 50 is, for example, 0.8 μm. The protective film 50 is made of, for example, SiN. The protective film 50 is a so-called passivation layer.

[0042] The insulating film 60 covers the upper surface 201 of the substrate 20 and the protective film 50. At this time, the insulating film 60 has a concave portion 691 whose bottom is included in the concave portion 501 of the protective film 50 and exposes the upper surface of the electrode 41, and a concave portion 692 whose bottom is included in the concave portion 502 of the protective film 50 and exposes the upper surface of the electrode 42. That is, the insulating film 60 covers the electrode 41, the electrode 42, the dielectric 31, the dielectric 32, the portion of the terminal electrode described later except the external connection portion, and a part of the substrate 20 (the upper surface 201).

[0043] The thickness of the insulating film 60 is, for example, 5.0 μm. The insulating film 60 is, for example, an organic film having a predetermined structure and having insulating properties. The insulating film 60 is a so-called solder resist.

[0044] The base electrode 71 for the terminal electrode is arranged on the upper surface 601 of the insulating film 60, the inner surface of the recess 691, and the surface of the electrode 41 exposed by the recess 691. The base electrode 71 is rectangular in a plan view. The base electrode 71 is formed by, for example, sequentially forming Ti and Cu electrode layers by sputtering, with the thickness of Ti being 0.1 μm and the thickness of Cu being 1.0 μm.

[0045] The external connection electrode 81 covers the upper surface of the base electrode 71. The external connection electrode 81 is, for example, a plated layer of Ni and Au formed in this order, with the thickness of Ni being 3.0 μm and the thickness of Au being 0.1 μm.

[0046] The base electrode 71 and the external connection electrode 81 constitute the “terminal electrode” (terminal electrode for upper electrode) of the present invention.

[0047] The base electrode 72 for the terminal electrode is arranged on the upper surface 601 of the insulating film 60, the inner surface of the recess 692, and the surface of the electrode 42 exposed by the recess 692. The base electrode 72 is rectangular in a plan view. The base electrode 72 is formed by, for example, sputtering method to form Ti and Cu electrode layers in sequence, with Ti having a thickness of 0.1 μm and Cu having a thickness of 1.0 μm.

[0048] The external connection electrode 82 covers the upper surface of the base electrode 72. The external connection electrode 82 is, for example, a plated layer of Ni and Au formed in this order, with the thickness of Ni being 3.0 μm and the thickness of Au being 0.1 μm.

[0049] The base electrode 72 and the external connection electrode 82 form a terminal electrode, more specifically, a "terminal electrode for the lower electrode" of the present invention. The base electrode 71 and the base electrode 72, the terminal electrode 81 and the terminal electrode 82 are schematically represented by rectangles. However, the corners may be rounded and the portion corresponding to the corner may be formed at an angle greater than 90 degrees by chamfering.

[0050] With the above-described structure, capacitor 10 realizes a capacitor formed using thin film technology (MIM capacitor).

[0051] (Specific Description of Discharge Function of Capacitor 10)

[0052] like Figure 2 As shown, in the capacitor 10 , the side surface 711 of the base electrode 71 serving as the terminal electrode is in contact with the upper surface 601 of the insulating film 60 , and is arranged near the side surface 611 of the insulating film 60 .

[0053] The distance between the side surface 711 and the side surface 611 of the insulating film 60 is defined as D761. More specifically, the distance D761 is the shortest distance between the side surface 711 and the side surface 611 along the upper surface 601 of the insulating film 60.

[0054] More specifically, thickness T611 is the shortest distance from a point where a straight line forming distance D761 meets side surface 611 to a side surface of substrate 20 along side surface 611 in the thickness direction (z-axis direction) of insulating film 60 .

[0055] Therefore, the sum of the distance D761 and the thickness T611 is the shortest distance between the terminal electrode and the outer surface of the substrate 20 along the insulating film 60. This shortest distance is referred to as Tsr (Tsr=D761+T611).

[0056] In addition, the thickness of the dielectric 31 is denoted as Td.

[0057] Furthermore, the shortest distance Tsr and the thickness Td satisfy the following relationship.

[0058] Tsr<18×Td 2 …(Formula 1)

[0059] By satisfying this relationship, the following effects are achieved.

[0060] Although this is just an example, a combination of a dielectric thickness Td of about 1.0 μm, a distance D761 of about 8 μm, and a thickness T611 of about 8 μm is conceivable.

[0061] Figure 3 It is a side cross-sectional view showing a discharge state of static electricity in the capacitor according to the first embodiment.

[0062] like Figure 3 As shown, static electricity (ESD) is applied to the terminal electrodes (external connection electrode 81 and base electrode 71 ) from the outside.

[0063] Here, if the relationship satisfying Expression 1 is satisfied, before the voltage generated by static electricity reaches the insulation breakdown voltage of the dielectric 31 , gas discharge occurs in the path (air path) passing through the surface of the insulating film 60 , and static electricity-induced charges flow toward the substrate 20 .

[0064] The substrate 20 is electrically connected to the lower electrode terminal electrode (external connection electrode 82 and base electrode 72) connected to an external ground potential via the electrode 42. Therefore, the charge flowing into the substrate 20 is discharged to the ground via the electrode 42 and the lower electrode terminal electrode.

[0065] Thereby, it is possible to suppress the charge caused by static electricity from being applied to the dielectric 31 between the electrode 41 and the substrate 20. Therefore, insulation breakdown of the dielectric 31 can be suppressed.

[0066] Figure 4 : is a graph showing the relationship between the dielectric breakdown of the dielectric constituting the capacitor, the thickness Td, and the shortest distance Tsr. Figure 4 In the equation (1), the solid line represents a curve (function) in which the inequality sign in (Equation 1) is replaced by an equality sign. Figure 4 The figure shows the state of dielectric breakdown when static electricity of 1 kV of HBM is applied to the terminal electrodes. OK means no dielectric breakdown, and NG means there is dielectric breakdown.

[0067] like Figure 4 As shown, since (Formula 1) is satisfied, insulation breakdown does not occur in the dielectric, but since (Formula 1) is not satisfied, insulation breakdown occurs.

[0068] Here, 1 kV is taken as an example, but the same tendency is obtained at 2 kV and 5 kV.

[0069] By satisfying the relationship of (Formula 1) in this way, capacitor 10 can suppress dielectric breakdown of dielectric 31 .

[0070] Furthermore, the capacitor 10 does not have a discharge function element newly provided as in the prior art. Therefore, the capacitor 10 can suppress dielectric breakdown of the dielectric 31 with a simple structure. Furthermore, the capacitor 10 can be thinner and smaller than a structure that has a discharge function element newly provided as in the prior art.

[0071] (An Example of a Method for Manufacturing Capacitor 10)

[0072] Figure 5 (A) Figure 5 (B) Figure 5 (C) Figure 5 (D) Figure 5 (E) Figure 6 (A) Figure 6 (B) Figure 6 (C) Figure 6 (D) is a cross-sectional view showing the structure of the capacitor according to the first embodiment of the present invention in each manufacturing process. In the following description of the manufacturing method, the parts specifically shown in the above description of the structure are omitted, and only parts that need to be newly described are described.

[0073] Put in substrate 20, such as Figure 5 As shown in (A), a dielectric 30 is formed on the upper surface 201 of the substrate 20. For example, SiO2 may be formed on a Si substrate as a thermal oxide film, or a SiO2 or SiN film may be formed by CVD (Chemical Vapor Deposition).

[0074] The dielectric 30 is patterned and etched, such as Figure 5 As shown in (B), dielectrics 31 and 32 are formed.

[0075] like Figure 5 As shown in (C), the electrode 40 is formed on the upper surface 201 side of the substrate 20 so as to cover the dielectric 31 and the dielectric 32. A metal such as Al or Cu may be formed by vapor deposition, sputtering, plating, or the like.

[0076] The electrode 40 is patterned and etched, such as Figure 5 As shown in (D), the electrode 41 and the electrode 42 are formed.

[0077] like Figure 5 As shown in (E), a protective film 50 (passivation film) is formed on the upper surface 201 side of the substrate 20 so as to cover the dielectric 31, the electrode 41, and the electrode 42. The protective film may be formed of SiO2, SiN, or the like by CVD or spin coating.

[0078] The protective film 50 is pattern-etched, such as Figure 6 As shown in FIG. 5A , a concave portion 501 exposing a portion of the upper surface of the electrode 41 and a concave portion 502 exposing a portion of the upper surface of the electrode 42 are formed in the protective film 50 .

[0079] like Figure 6 As shown in (B), the insulating film 60 is formed so as to cover the protective film 50. At this time, the insulating film 60 has a concave portion 691 and a concave portion 692.

[0080] like Figure 6 As shown in (C), the power supply film 70 is formed so as to cover the upper surface 601 of the insulating film 60, the wall surface of the recess 691, and the wall surface of the recess 692. The power supply film 70 is realized by, for example, sputtering or electroless plating.

[0081] like Figure 6 As shown in (D), the external connection electrodes 81 and 82 are formed in regions including the recessed portions 691 and 692 in the power supply film 70. The external connection electrodes 81 and 82 are implemented by electrolytic plating using a mask, for example.

[0082] Then, the power supply film 70 is pattern-etched to form the base electrode 71 and the base electrode 72 .

[0083] The processing up to this point is performed in a state where a plurality of capacitors 10 are arranged on the mother substrate. Then, the substrate 20 is appropriately ground from the lower surface 202 side, and the mother substrate is cut to separate the plurality of capacitors 10 into individual pieces.

[0084] [Second embodiment]

[0085] A capacitor according to a second embodiment of the present invention will be described with reference to the drawings. Figure 7 (A) is a plan view of a capacitor according to a second embodiment of the present invention. Figure 7 (B) shows Figure 7 (A) is a diagram of the AB cross section shown. Figure 8 This is an enlarged cross-sectional view of the vicinity of the side surface of the capacitor and the vicinity of the side surface of the terminal electrode according to the second embodiment of the present invention.

[0086] like Figure 7 (A) Figure 7 (B) Figure 8 As shown, the capacitor 10A according to the second embodiment differs from the capacitor 10 according to the first embodiment in the structure of the terminal electrodes (base electrode 71A, external connection electrode 81A). The other structures of the capacitor 10A are the same as those of the capacitor 10, and the description of the same parts is omitted.

[0087] The base electrode 71A is rectangular in a plan view and includes a side surface 711, a side surface 712, a side surface 713, and a side surface 714. The side surface 711 is close to and parallel to the side surface 611 of the insulating film 60. The side surface 712 is opposite to the side surface 711 and is a side surface on the base electrode 72 side of the base electrode 71A. The side surface 713 is close to and parallel to the side surface 613 of the insulating film 60. The side surface 714 is opposite to the side surface 713 and is close to and parallel to the side surface 614 of the insulating film 60. In addition, the parallelism here is not limited to being completely parallel, but is parallelism within a range including manufacturing errors.

[0088] The base electrode 71A includes a main portion, a protruding portion 791, a protruding portion 793, and a protruding portion 794. The main portion of the base electrode 71A is a rectangular portion in the above-described plan view.

[0089] In a plan view of the base electrode 71A, the protrusion 791 protrudes from the side surface 711 of the main portion toward the side surface 611 of the insulating film 60. At this time, the width of the protrusion 791 is smaller than the width of the side surface 711.

[0090] In a plan view of the base electrode 71A, the protrusion 793 protrudes from the side surface 713 of the main portion toward the side surface 613 of the insulating film 60. At this time, the width of the protrusion 793 is smaller than the width of the side surface 713.

[0091] In a plan view of the base electrode 71A, the protrusion 794 protrudes from the side surface 714 of the main portion toward the side surface 614 of the insulating film 60. At this time, the width of the protrusion 794 is smaller than the width of the side surface 714.

[0092] In such a structure, the shortest distance Tsr is further the shortest distance among the shortest distance from the front end 7911 of the protrusion 791 to the side of the substrate 20 along the outer surface of the insulating film 60 (the upper surface 601 and the side 611), the shortest distance from the front end 7931 of the protrusion 793 to the side of the substrate 20 along the outer surface of the insulating film 60 (the upper surface 601 and the side 613), and the shortest distance from the front end 7941 of the protrusion 794 to the side of the substrate 20 along the outer surface of the insulating film 60 (the upper surface 601 and the side 614).

[0093] For example, in Figure 8 In the case of , the distance between the front end 7911 of the protrusion 791 and the side surface 611 of the insulating film 60 is D761A, and the shortest distance Tsr is the sum of the distance D761A and the thickness T611. In addition, although this is an example, for a dielectric thickness Td of about 1.0 μm, a combination of a distance D761A of about 3 μm and a thickness T611 of about 8 μm is considered.

[0094] With such a configuration, capacitor 10A can release static electricity by gas discharge, similarly to capacitor 10 , and can suppress dielectric breakdown of dielectric 31 .

[0095] Furthermore, the capacitor 10A can control the position of the gas discharge from the terminal electrode. In addition, the capacitor 10A can shorten the shortest distance Tsr without changing the position of the terminal electrode on the side 711 of the side 611 of the insulating film 60. As a result, the capacitor 10A can reduce the terminal electrode while ensuring the discharge performance, and can reduce the parasitic capacitance formed by the terminal electrode and the substrate 20.

[0096] In capacitor 10A, the shapes of tip 7911 of protrusion 791, tip 7931 of protrusion 793, and tip 7941 of protrusion 794 are tapered. Thus, capacitor 10A can further control the discharge portion.

[0097] In addition, in capacitor 10A, a mode is shown in which three protrusions (protrusion 791, protrusion 793, and protrusion 794) are provided. However, the number of protrusions is not limited thereto, as long as there is at least one. In addition, for example, a plurality of protrusions may be provided on one side surface.

[0098] In addition, when the capacitor 10A has an even number of protrusions, such as two, the side surfaces 713 and 714 can be arranged in pairs. Thus, even if the capacitor 10A is displaced when being cut from the mother substrate and singulated, one of the protrusions on the side surface 713 and the protrusions on the side surface 714 is always arranged to satisfy the above-mentioned (Formula 1). Thus, the capacitor 10A can more reliably suppress the insulation breakdown of the dielectric 31.

[0099] [Third Embodiment]

[0100] A capacitor according to a third embodiment of the present invention will be described with reference to the drawings. Fig. 9 This is an enlarged cross-sectional view of the vicinity of the side surface of the capacitor and the vicinity of the side surface of the terminal electrode according to the third embodiment of the present invention.

[0101] like Fig. 9 As shown, the capacitor 10B according to the third embodiment differs from the capacitor 10A according to the second embodiment in the structure of the terminal electrodes (base electrode 71B, external connection electrode 81B). The other structures of the capacitor 10B are the same as those of the capacitor 10A, and the description of the same parts is omitted.

[0102] The external connection electrode 81B has a larger outer shape than the base electrode 71B. For example, the side surface 891B on the side surface 611 of the insulating film 60 in the external connection electrode 81B protrudes further toward the side surface 611 than the side surface 711 on the side surface 611 of the insulating film 60 in the base electrode 71B.

[0103] In addition, a gap GAP is formed between the external connection electrode 81B and the insulating film 60 at a portion of the external connection electrode 81B that protrudes from the base electrode 71B. The gap GAP is, for example, about 0.1 μm to 2.0 μm. Such a gap GAP can be realized by selectively etching the base electrode 71B more easily than the external connection electrode 81B.

[0104] In such a structure, the distance D861B between the side surface 891B of the external connection electrode 81B (for example, the front end of the protrusion of the external connection electrode 81B corresponding to the protrusion 791) and the side surface 611 of the insulating film 60 can be made shorter than the distance between the side surface 711B of the base electrode 71B (for example, the front end of the protrusion 791) and the side surface 611 of the insulating film 60. In this case, the shortest distance Tsr becomes the sum of the distance D861B and the thickness T611.

[0105] With such a structure, capacitor 10B achieves the same function and effect as capacitor 10B.

[0106] Furthermore, in the capacitor 10B, the area of ​​the upper surface 601 of the base electrode 71B disposed on the insulating film 60 can be reduced. Thus, the capacitor 10B can suppress the parasitic capacitance generated between the electrode 41 and the base electrode 71B. In particular, Fig. 9 As shown, compared with the side surface 611 of the insulating film 60 in the electrode 41, only the side surface 711B of the base electrode 71B is located farther from the side surface 611 of the insulating film 60 (see Fig. 9 ), thereby further reducing the facing area between the electrode 41 and the base electrode 71B. Therefore, the capacitor 10B can further suppress the parasitic capacitance generated between the electrode 41 and the base electrode 71B.

[0107] Moreover, in such a structure, the external connection electrode 81B can also suppress the shortest distance Tsr from becoming longer, and gas discharge at a desired voltage can be achieved. Furthermore, in the region where the external connection electrode 81B and the electrode 41 are opposed to each other without separating the base electrode 71B therebetween, there is a gap GAP, so the capacitor 10B can suppress the parasitic capacitance generated between the electrode 41 and the external connection electrode 81B.

[0108] [Fourth embodiment]

[0109] A capacitor according to a fourth embodiment of the present invention will be described with reference to the drawings. Fig.10 (A) is a top view of a capacitor according to a fourth embodiment of the present invention. Fig.10 (B) shows Fig.10 (A) is a diagram of the AB cross section shown.

[0110] like Fig.10 (A) Fig.10 As shown in (B), the capacitor 10C according to the fourth embodiment is different from the capacitor 10A according to the second embodiment in that an insulating film 90 is provided. The other structures of the capacitor 10C are the same as those of the capacitor 10A, and the description of the same parts is omitted.

[0111] The insulating film 90 of the capacitor 10C covers the insulating film 60, the base electrode 71C (same structure as the base electrode 71A), the base electrode 72, the external connection electrode 81C (same structure as the external connection electrode 81A), and the external connection electrode 82. At this time, the insulating film 90 exposes to the outside the central portion of the external connection electrode 81C (the portion used as the mounting electrode) when viewed from above, the central portion of the external connection electrode 82 (the portion used as the mounting electrode) when viewed from above, the portion of the base electrode 71C including the front end 7911 of the protrusion 791, the portion of the base electrode 71C including the front end 7931 of the protrusion 793, and the portion of the base electrode 71C including the front end 7941 of the protrusion 794.

[0112] The insulating film 90 and the insulating film 60 may be made of the same material or different materials, but by making them the same material, it is expected that the adhesion between the insulating film 60 and the insulating film 90 will be improved. When formed of the same material, the boundary between the insulating film 60 and the insulating film 90 may not be clear.

[0113] With such a structure, the capacitor 10C can mitigate the impact during installation. In addition, the protrusion of the capacitor 10C is exposed from the insulating film 90, so that the insulation breakdown of the dielectric 31 caused by the gas discharge of static electricity can be suppressed as in the capacitor 10A. That is, the capacitor 10C has the same effect as the capacitor 10A.

[0114] [Fifth embodiment]

[0115] A capacitor according to a fifth embodiment of the present invention will be described with reference to the drawings. Fig.11 It is a diagram showing a cross section of a capacitor according to a fifth embodiment of the present invention. Fig.11 Shown with Figure 1 (A) shows the same AB section.

[0116] like Fig.11As shown, the capacitor 10D according to the fifth embodiment is different from the capacitor 10 according to the first embodiment in that it includes an electrode 41LP and an electrode 42D instead of the electrode 42. The other structures of the capacitor 10D are the same as those of the capacitor 10, and the description of the same parts is omitted.

[0117] The electrode 41LP is disposed between the substrate 20 and the dielectric 31. The electrode 41LP is connected to the substrate 20. The electrode 41LP and the electrode 41 face each other with the dielectric 31 interposed therebetween.

[0118] In this structure, the electrode 41LP and the substrate 20 constitute the “lower electrode” of the present invention.

[0119] The electrode 42D is formed by a combination of an electrode film formed at the same timing as the electrode 41LP and the electrode 42 in the capacitor 10 , and covers the entire surface of the dielectric 32 .

[0120] With such a structure, the capacitor 10D has the same function and effect as the capacitor 10 .

[0121] [Sixth embodiment]

[0122] A capacitor according to a sixth embodiment of the present invention will be described with reference to the drawings. Fig.12 It is a diagram showing a cross section of a capacitor according to a sixth embodiment of the present invention. Fig.12 and Fig.11 Likewise, Figure 1 (A) shows the same AB section.

[0123] like Fig.12 As shown, the capacitor 10E according to the sixth embodiment is different from the capacitor 10D according to the fifth embodiment in that it includes a lower protection film 50LP, a plurality of via conductors 419, and a plurality of via conductors 429. The other structures of the capacitor 10E are the same as those of the capacitor 10D, and the description of the same parts is omitted.

[0124] The capacitor 10E includes a lower protection film 50LP on the upper surface 201 of the substrate 20. The lower protection film 50LP is made of the same material as the protection film 50, for example.

[0125] The lower protection film 50LP is disposed between the substrate 20 and the electrode 41LP, and is disposed between the substrate 20 and the electrode 42E (having the same structure as the electrode 42D).

[0126] The plurality of via-hole conductors 419 are formed in the lower protection film 50LP and penetrate the lower protection film 50LP in the thickness direction. The plurality of via-hole conductors 419 connect and conduct the substrate 20 and the electrode 41LP.

[0127] The plurality of via-hole conductors 429 are formed in the lower protection film 50LP and penetrate the lower protection film 50LP in the thickness direction. The plurality of via-hole conductors 429 connect and conduct the substrate 20 and the electrode 42E.

[0128] With such a structure, the capacitor 10E has the same operational effect as the capacitor 10D.

[0129] [Seventh embodiment]

[0130] A capacitor according to a seventh embodiment of the present invention will be described with reference to the drawings. Fig.13 It is a diagram showing a cross section of a capacitor according to a seventh embodiment of the present invention. Fig.13 Shown with Figure 1 (A) shows the same AB section.

[0131] like Fig.13 As shown, the capacitor 10F according to the seventh embodiment is different from the capacitor 10 according to the first embodiment in that it includes an electrode 20e and a substrate 20i instead of the substrate 20. The other structures of the capacitor 10F are the same as those of the capacitor 10, and the description of the same parts is omitted.

[0132] The substrate 20i is an insulating substrate and is made of, for example, aluminum oxide.

[0133] The electrode 20e is arranged on the upper surface 201 of the substrate 20i. The electrode 20e has conductivity. The lower electrode is realized by the electrode 20e arranged on the insulating substrate 20i in this way.

[0134] The dielectric 31 and the dielectric 32 are arranged on the upper surface of the electrode 20 e (the surface facing the surface in contact with the substrate 20 i ).

[0135] In the capacitor 10F, T611 is not the distance from the substrate but the distance from the electrode 20 e .

[0136] With such a structure, the capacitor 10F has the same function and effect as the capacitor 10 .

[0137] Here, for convenience, the shape of the insulating film 60 is shown as a rectangle when viewed from the Y-axis direction, but it does not necessarily need to be a rectangle, and may be a shape in which a straight line is connected from the base electrode or the connection terminal electrode to the substrate, or a shape in which a curved line is connected from the base electrode or the connection terminal electrode to the substrate. Regardless of the shape, as long as the shortest distance from the base electrode or the connection terminal electrode to the surface of the substrate where each functional film is not formed through the insulating film 60 is set to Tsr and equation 1 is satisfied.

[0138] Here, an example is shown in which the side surface 611 of the insulating film 60 is integrated with the side surface of the substrate, but the substrate 20 may extend beyond the capacitor forming portion when viewed from the Z-axis direction. In this case, the distance between a point on the upper surface 201 of the substrate 20 and the end of the base electrode or the connection terminal electrode becomes the shortest distance Tsr.

[0139] In addition, the structures of the above-mentioned embodiments can be combined as appropriate, and the effects corresponding to the respective combinations can be achieved.

[0140] <1> A capacitor having:

[0141] Lower electrode;

[0142] A dielectric disposed on the upper surface of the lower electrode;

[0143] an upper electrode disposed on an upper surface of the dielectric and facing the lower electrode with the dielectric sandwiched therebetween;

[0144] a terminal electrode for external connection, arranged on the upper surface of the upper electrode and electrically connected to the upper electrode; and

[0145] an insulating film covering the upper electrode, the dielectric, a portion of the terminal electrode excluding an external connection portion, and a portion of the lower electrode,

[0146] Let the thickness of the dielectric be Td,

[0147] A distance along the surface of the insulating film connecting a portion of the terminal electrode not covered by the insulating film and a portion of the lower electrode not covered by the insulating film is defined as Tsr.

[0148] The Td and the Tsr satisfy Tsr<18×Td 2 relationship.

[0149] <2> according to <1> The capacitor, wherein

[0150] The terminal electrode includes a protruding portion protruding from a side surface of a main portion having a predetermined shape in a plan view,

[0151] The distance Tsr is a distance connecting the protrusion and the lower electrode.

[0152] <3> according to <2> The capacitor, wherein

[0153] The protruding portion includes a plurality of protruding portions arranged at positions opposing each other across the main portion.

[0154] <4> according to <2> or <3> The capacitor, wherein

[0155] The front end of the protrusion is in a tapered shape.

[0156] <5> according to <1> to <3> A capacitor as described in any one of the above, wherein

[0157] The terminal electrode comprises:

[0158] a substrate electrode electrically connected to the upper electrode; and

[0159] an external connection electrode formed on the substrate electrode,

[0160] The base electrode and the external connection electrode have portions facing the upper electrode.

[0161] The external connection electrode protrudes more than the base electrode,

[0162] In a portion where the external connection electrode protrudes beyond the base electrode, a gap is provided between the external connection electrode and the upper electrode.

[0163] <6> according to <1> to <5> A capacitor as described in any one of the above, wherein

[0164] The lower electrode is a conductive semiconductor substrate.

[0165] <7> according to <6> The capacitor, wherein

[0166] The lower electrode includes a conductive film disposed between a conductive semiconductor substrate and the dielectric.

[0167] <8> according to <1> to <5> A capacitor as described in any one of the above, wherein

[0168] The lower electrode comprises:

[0169] an insulating substrate; and

[0170] The conductive film is arranged between the insulating substrate and the dielectric.

[0171] <9> according to <1> to <8> A capacitor as described in any one of the above, wherein

[0172] The terminal electrode is electrically connected to the upper electrode,

[0173] The capacitor further includes a lower electrode terminal electrode electrically connected to the lower electrode.

[0174] <10> according to <6> or <7> The capacitor, wherein

[0175] The semiconductor substrate is Si,

[0176] The dielectric is SiO2.

[0177] Description of Reference Numerals

[0178] 10, 10A, 10B, 10C, 10D, 10E, 10F: Capacitors

[0179] 20, 20i: substrate

[0180] 20e: Electrode

[0181] 30, 31, 32: Dielectric

[0182] 40, 41, 41LP, 42, 42D, 42E: Electrodes

[0183] 50: Protective film

[0184] 50LP: Lower protective film

[0185] 60: Insulation film

[0186] 70: Power supply film

[0187] 71, 71A, 71B, 71C, 72: Base electrode

[0188] 81, 81A, 81B, 81C, 82: External connection electrodes

[0189] 90: Insulation film

[0190] 201: Upper surface

[0191] 202: Lower surface

[0192] 419, 429: Via conductor

[0193] 501, 502: concave part

[0194] 601: Upper surface

[0195] 611, 613, 614: Side

[0196] 691, 692: concave part

[0197] 711, 711B, 712, 713, 714: Side

[0198] 791, 793, 794: Protrusion

[0199] 891B: Side

[0200] 7911, 7931, 7941: front end.

Claims

1. A capacitor having: Lower electrode; A dielectric disposed on the upper surface of the lower electrode; an upper electrode disposed on an upper surface of the dielectric and facing the lower electrode with the dielectric sandwiched therebetween; A terminal electrode for external connection is arranged on the upper surface of the upper electrode and is electrically connected to the upper electrode; and an insulating film covering the upper electrode, the dielectric, a portion of the terminal electrode excluding an external connection portion, and a portion of the lower electrode, Let the thickness of the dielectric be Td, The shortest distance along the surface of the insulating film connecting the portion of the terminal electrode not covered by the insulating film and the portion of the lower electrode not covered by the insulating film is defined as Tsr. Thickness Td and distance Tsr satisfy Tsr < 18 × Td 2 relationship.

2. The capacitor according to claim 1, wherein: The terminal electrode includes a protrusion that protrudes from a side surface of a main portion having a predetermined shape in a plan view. The distance Tsr is a distance connecting the protrusion and the lower electrode.

3. The capacitor according to claim 2, wherein: The protruding portion includes a plurality of protruding portions arranged at positions opposing each other across the main portion.

4. The capacitor according to claim 2 or 3, wherein: The front end of the protrusion is in a tapered shape.

5. The capacitor according to any one of claims 1 to 3, wherein: The terminal electrode comprises: a substrate electrode electrically connected to the upper electrode; and an external connection electrode formed on the substrate electrode, The base electrode has a portion in contact with a surface of the upper electrode on the opposite side of the surface in contact with the dielectric. The external connection electrode has a portion that is in contact with the upper electrode on the opposite side of the surface of the base electrode that is in contact with the upper electrode, and protrudes beyond the base electrode. In a portion where the external connection electrode protrudes beyond the base electrode, a gap is provided between the external connection electrode and the upper electrode.

6. The capacitor according to any one of claims 1 to 5, wherein: The lower electrode is a conductive semiconductor substrate.

7. The capacitor according to claim 6, wherein: The lower electrode includes a conductive film disposed between a conductive semiconductor substrate and the dielectric.

8. The capacitor according to any one of claims 1 to 5, wherein: The lower electrode comprises: an insulating substrate; and The conductive film is arranged between the insulating substrate and the dielectric.

9. The capacitor according to any one of claims 1 to 8, wherein: The terminal electrode is electrically connected to the upper electrode, The capacitor further includes a lower electrode terminal electrode electrically connected to the lower electrode.

10. The capacitor according to claim 6 or 7, wherein: The semiconductor substrate is Si, The dielectric is SiO2.

Images