To provide a thin film capacitor in which peeling-off of an electrode layer is less likely to occur. A thin film capacitor includes a metal foil having a roughened upper surface, a dielectric film covering the upper surface of the metal foil and having an opening for partly exposing the metal foil therethrough, a first electrode layer contacting the metal foil through the opening and further contacting the dielectric film, and a second electrode layer contacting the dielectric film without contacting the metal foil. With this configuration, both the first and second electrode layers can be disposed on the upper surface of the metal foil. In addition, the first electrode layer contacts not only the metal foil but also the dielectric film, making peeling of the first electrode layer less likely to occur.

To provide a thin film capacitor having high adhesion with respect to a circuit substrate. A thin film capacitor includes: a metal foil having a roughened upper surface; a dielectric film covering the upper surface of the metal foil and having an opening through which the metal foil is partly exposed; a first electrode layer contacting the metal foil through the opening; and a second electrode layer contacting the dielectric film without contacting the metal foil. An angle θa formed by the other main surface of the metal foil and a side surface thereof is more than 20° and less than 80°. The side surface is thus tapered at an angle of more than 20° and less than 80°, so that it is possible to suppress warpage and to enhance adhesion with respect to a multilayer substrate when the thin film capacitor is embedded in the multilayer substrate.

A film capacitor that includes: a dielectric resin film; and a metal layer on at least one surface of the dielectric resin film. The dielectric resin film contains at least one skeleton selected from the group consisting of a biphenyl skeleton, a bisphenol acetophenone skeleton, a bisphenol fluorene skeleton, a bisphenol S skeleton, a bisphenol cyclohexanone skeleton, and an epoxy-modified bisphenol A skeleton.

A thin film capacitor includes: a metal foil having a roughened upper surface; a dielectric film covering the upper surface of the metal foil and having an opening through which the metal foil is partly exposed; a first electrode layer contacting the metal foil through the opening; a second electrode layer contacting the dielectric film without contacting the metal foil; and an insulating member separating the first and second electrode layers. The insulating member has a tapered shape in cross section. With the above configuration, both the first and second electrode layers can be disposed on the upper surface of the metal foil. In addition, since the insulating member has a tapered shape in cross section, adhesion performance of the insulating member can be enhanced, thus making it possible to prevent short-circuit between the first and second electrode layers.

To provide a thin film capacitor in which warpage is less likely to occur. A thin film capacitor includes: a metal foil having roughened upper and lower surfaces; a dielectric film covering the upper surface of the metal foil and having an opening through which the metal foil is partly exposed; a dielectric film covering the lower surface of the metal foil and made of a dielectric material having a thermal expansion coefficient smaller than that of the metal foil; a first electrode layer contacting the metal foil through the opening; and a second electrode layer contacting the first dielectric film without contacting the metal foil. The lower surface of the metal foil is thus covered with the dielectric film having a small thermal expansion coefficient, thereby making it possible to prevent the occurrence of warpage.

To provide a thin film capacitor having high adhesion performance with respect to a circuit substrate. A thin film capacitor includes: a metal foil having a roughened upper surface; a dielectric film covering the upper surface of the metal foil and having an opening through which the metal foil is partly exposed; a first electrode layer contacting the metal foil through the opening; and a second electrode layer contacting the dielectric film without contacting the metal foil. The first and second electrode layers are formed in an area surrounded by an outer peripheral area of the upper surface of the metal foil so as not to cover the outer peripheral area. The outer peripheral area of the roughened upper surface of the metal foil is thus exposed, so that adhesion performance with respect to a circuit substrate can be enhanced.

To provide a thin film capacitor in which a pair of terminal electrodes can be disposed on the same plane. A thin film capacitor includes a metal foil having a roughened upper surface, a dielectric film covering the upper surface of the metal foil and having an opening for partly exposing the metal foil therethrough, a first electrode layer contacting the metal foil through the opening, and a second electrode layer contacting the dielectric film without contacting the metal foil. With this configuration, both the first and second electrode layers can be disposed on the upper surface of the metal foil. In addition, since the metal foil is surface-roughened, a larger capacitance can be obtained.

To provide a thin film capacitor having high flexibility. A thin film capacitor includes: a metal foil having a roughened upper surface; a dielectric film covering the upper surface of the metal foil and having an opening through which the metal foil is partly exposed; a first electrode layer contacting the metal foil through the opening; and a second electrode layer contacting the dielectric film without contacting the metal foil. The particle diameter of crystal at a non-roughened center part of the metal foil is less than 15 μm in the planar direction and less than 5 μm in the thickness direction. This can not only enhance the flexibility of the metal foil to reduce a short-circuit failure in a state where the thin film capacitor is incorporated in a multilayer substrate but also enhance positional accuracy.

The disclosure belongs to the field of film materials, and discloses a high-temperature resistant modified polypropylene film, and a preparation method and use thereof. The modified polypropylene film includes a polypropylene film, and an oxide layer and/or nitride layer, each of which has a thickness of 20-500 nm, on the surface of the polypropylene film. It can significantly improve the thermal stability and high-temperature withstand voltage property of the polypropylene film by depositing the oxide layer or nitride layer of appropriate thickness on the surface of the polypropylene film by an ALD technology. The modified polypropylene film has high-temperature resistance, such as resistance to at high temperature of 150° C., and very small deformation quantity at high temperature, and can withstand a high breakdown voltage at high temperature. For example, the modified polypropylene film can withstand a voltage of 580 kV/mm at 140° C. The modified polypropylene film has widespread applications in the field of electronic products with high temperature requirements, such as the field of capacitors.

A capacitor cell element includes a dielectric, which has a first metal coating on a first side and has a second metal coating on a second side. The first metal coating on the first side leaves free a first edge region, and the second metal coating on the second side leaves free a second edge region. The first edge region and the second edge region are disposed at opposite ends of the dielectric. A capacitor including the capacitor cell element is also provided. The capacitor cell element and the capacitor have a high volumetric energy density and at the same time are self-healing.