JPH01200609A - Laminated film capacitor - Google Patents

Abstract

PURPOSE:To enable the use of the subject capacitor as a printed wiring substrate, and realize large capacitance, by laminating plastic films provided with internal electrodes, forming capacitor elements, and arranging external electrodes on one end thereof. CONSTITUTION:One or more internal electrodes 2A, 2B are arranged on plastic films 4A, 4B, and capacitance elements 7 using the plastic film as dielectric are formed, by laminating the plastic films 4A, 4B. By providing the capacitance elements 7 with external electrodes 6A, 6B, a laminated film capacitor constituting the form of a printed wiring substrate is obtained. That is, the internal electrode 2A, 2B may be selectively formed in a part of the plastic films 4A, 4B, and the other part is used for area of connection terminals to mount electronic components. Thus, the laminated film capacitor itself can be operated as a printed wiring substrate, thereby enabling the use as a printed wiring substrate, and the increase of capacitance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multilayer film capacitor that can be used as a printed wiring board.

[Conventional technology]

Conventionally, film capacitors are used mounted on printed wiring boards, and printed wiring boards are used to form desired circuits by mounting element parts such as resistors, transistors, capacitors, and C.

(Problem to be solved by the invention) In order to make electronic devices smaller and lighter, various electronic components are becoming smaller and printed wiring boards are also desired to have higher density, but electronic circuits are becoming more complex. Due to such factors, capacitors are frequently used, and it is difficult to increase the density of printed wiring boards themselves, and the proportion of printed wiring boards is increasing.Furthermore, although capacitors are becoming smaller due to chipping, In some cases, the smaller size cannot meet the required capacity, and it is still necessary to use a large-capacity one.

Therefore, the present invention aims to realize a multilayer film capacitor that can be used as a printed wiring board and has an increased capacity, thereby making the component multifunctional.

[Means for Solving the Problems] As shown in FIG. 1, the laminated film capacitor of the present invention is constructed by laminating a plurality of plastic films 4A and 4B on which one or more internal electrodes 2A and 2B are installed. to form a capacitor element 7, and a plastic film 4A.
, 4B is installed on the inner wall surface of the hole formed in the internal electrode 2A.
, 2B, an external electrode 6 made of a conductive layer electrically connected to
A and 6B are installed.

In the laminated film capacitor of the present invention, the plastic films 4A and 4B are made of aromatic polyamide, polyimide, polyamideimide, aromatic polyester, or polyamino bismaleimide as a heat-resistant resin.

Further, in the multilayer film capacitor of the present invention, the internal electrodes 2A, 2B are made of plastic films 4A, 4B.
It can be formed on the surface by printing means or vapor deposition means.

[For production]

By installing one or more internal electrodes 2A, 2B on the plastic films 4A, 4B and laminating the plastic films 4A, 4B, a capacitor element 7 having the plastic films 4A, 4B as dielectrics is formed. . This capacitor element 7 has external electrodes 6A, 6B.
By installing this, a laminated film capacitor shaped like a printed wiring board can be obtained. That is, in this capacitor, the internal electrodes 2A, 2B may be selectively formed on a portion of the plastic films 4A, 4B, and the other portions may be used only for the connection terminal area. By using this area for mounting other electronic components, the multilayer film capacitor itself can function as a printed wiring board.

In the multilayer film capacitor of this invention,
The external electrodes 6A, 6B can be formed by a conductive layer installed on the inner wall surface of the hole formed in the plastic films 4A, 4B of the capacitor element 7, and electrically connected to the internal electrodes 2A, 2B. , 6B and an external connection terminal, and can be made a part of the printed wiring board.

In the laminated film capacitor of the present invention, high heat resistance can be obtained if the plastic films 4A and 4B are made of aromatic polyamide, polyimide, polyamideimide, aromatic polyester, or polyamino bismaleimide. In other words, even when this laminated film capacitor is used as a printed wiring board and other mounted elements are electrically connected by soldering, the plastic films 4A and 4B do not deteriorate and the function as a capacitor is not impaired. There is no.

Further, in the multilayer film capacitor of the present invention, the internal electrodes 2A, 2B are made of plastic films 4A, 4B.
If formed on the surface of by printing means or vapor deposition means,
Reliability as an electrode can be obtained.

〔Example〕

FIG. 1 shows an embodiment of the multilayer film capacitor of the present invention.

In this laminated film capacitor, a plurality of plastic films 4A, 4B are laminated, on which one or more internal electrodes 2A, 2B are installed, external electrodes 6A, 6B are installed, and one or more capacitor elements 7 are installed. is formed. That is, this multilayer film capacitor is formed into a sheet shape by laminating plastic films 4A and 4B, and has flexibility, and is a printed wiring board on which other elements such as transistors and ICs are installed. It is available as.

FIG. 2 shows a cross section taken along the line ■--■ in FIG. The plastic films 4A and 4B are made of aromatic polyamide, polyimide, polyamideimide, aromatic polyester, or polyamino bismaleimide as a highly heat-resistant resin.
．． It is formed with a j7 diameter of 5 to 10 μm. internal electrode 2A,
2B is formed by printing means or vapor deposition means, and as shown in FIG. 3, has notches 8A and 8B,
For example, it is formed into a rectangular shape. Notches 8A, 8B
The narrow portions 10A and IOB formed by the above are left as conductive portions that connect the electrode portions contributing as the capacitor element 7, and are the forming portions of the external electrodes 6A and 6B.

The plastic films 4A and 4B on which the internal electrodes 2A and 2B are installed in this way are arranged alternately, and
These two are bonded with adhesive resin 12 interposed between them, and formed into a single sheet consisting of a plurality of plastic films 4A and 4B.

In this case, the plastic films 4A and 4B are overlapped with the notch portions 8A and 8B aligned, so that the narrow portion 10B of the internal electrode 2B is aligned with the notch portion 8A of the internal electrode 2A.
straddles the notch 8B of the internal electrode 2B, and the narrow part 10A of the internal electrode 2A straddles the notch 8B of the internal electrode 2B. Only the narrow portion 10A of the internal electrode 2A is overlapped. Therefore, through holes 14A and 14B are formed in the portion where only the internal electrode 2A or the internal electrode 2B is overlapped. An external electrode 6 having a through hole 16 inside with a conductive layer made of wax or the like on the inner wall surface of the through hole 14A and the opening edge thereof.
A is formed.

One or more internal electrodes 2A are electrically connected to this external electrode 6A depending on the position where each internal electrode is formed. Similarly, an external electrode 6B having a through hole 16 inside is formed using a conductive layer made of plating or the like on the inner wall surface of the through hole 14B and the opening edge thereof, and the external electrode 6B has a conductive layer formed on the inner wall surface of the through hole 14B and the opening edge thereof. One or more internal electrodes 2B are electrically connected to each other.
, 14B, the connection between adjacent capacitor elements 7 can be selected depending on whether or not to form a conductive layer on the external electrode 6A. , 6B by electrode printing, a plurality of capacitor elements 7 can be connected in series and parallel, and a desired capacitance value can be obtained.

In this case, after the plastic films 4A and 4B are laminated, the narrow part 10A forming the conductive part of the internal electrodes 2A and 2B is
By forming through-holes 14A and 14B in the IOB that exceed the width thereof, the internal electrodes 2A and 2B connected through the narrow portion 10A and the IOB can be separated into two or more parts to form independent capacitor elements 7. That is, the formation interval of the notches 8A, 8B of each internal electrode 2A, 2B can be set according to the unit capacitance, and can be made to correspond to the capacitance value required by connection or disconnection.

In this way, highly heat-resistant plastic films 4A and 4B
are laminated, and one or more capacitor elements 7 are stacked therein.
By incorporating a capacitor, it is possible to increase the capacitance and reduce the thickness of the capacitor, and it can also be used as a printed wiring board, so the mounting space for the capacitor can be reduced compared to a conventional printed wiring board.

Further, the external electrodes 6A, 6B are drawn out from the internal electrodes 2A, 2B by using conductive layers formed by plating the through holes 14A, 14B and their inner walls, and the lead wire parts are connected to the respective external electrodes 6A, 6B. Moreover, if the external electrodes 6A and 6B are formed in recessed holes, it is also possible to mount surface-mounted components by forming lands in the recessed holes.

In the embodiment, the through holes 14A and 14B were formed in order to form the external electrodes 6A and 6B, but a concave hole was formed and a conductive layer was placed in the hole to connect the internal electrodes 2A and 2B. Electrical connections may also be made. In addition, the shapes of the plastic films 4A, 4B, internal electrodes 2A, 2B, and external electrodes 6A, 6B can be freely set according to the requirements of the printed wiring board, capacitance value, installation space of electronic equipment, etc. In order to enhance the functionality, connecting terminals 18 and wiring conductors may be formed on the surfaces of the plastic films 4A, 4B or penetrating inside them.

[Effects of the Invention] As explained above, according to the present invention, a capacitor element is formed by laminating plastic films on which one or more internal electrodes are installed, and an external electrode is installed at one end of the capacitor element. The laminated plastic film has a capacitor element inside, and can be used as a printed wiring board with resistors, transistors, other elements, and wiring conductors installed, and can be expected to have a large capacity, so any capacitance value can be set. can do.

Furthermore, since the plastic film is made of heat-resistant resin, when used as a printed wiring board, it can sufficiently withstand soldering of other electronic components to be mounted.

If internal electrodes are formed on the surface of the plus-thin film by printing or vapor deposition, highly reliable internal electrodes can be obtained and good electrical characteristics can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the multilayer film capacitor of the present invention, FIG. 2 is a sectional view taken along the line II-If of FIG. 1, and FIG. 3 shows the capacitor element of the multilayer film capacitor shown in FIG. FIG. 2 is an exploded perspective view showing a plastic film and internal electrodes. 2A, 2B... Internal electrodes 4A, 4B... Plastic films 6A, 6B...
・External electrode 7...Capacitor element 8A, 8B...Notch portion 10A, 10B...Narrow portion 14A, 14B...Through hole

Claims (3)

[Claims] (1) A capacitor element is formed by laminating a plurality of plastic films each having one or more internal electrodes installed, and is installed on the inner wall surface of a hole formed in the plastic film to electrically connect the internal electrodes. A multilayer film capacitor with an external electrode consisting of connected conductive layers. (2) Claim 1 wherein the plastic film is made of any one of aromatic polyamide, polyimide, polyamideimide, aromatic polyester, and polyamino bismaleimide.
The multilayer film capacitor described. (3) The multilayer film capacitor according to claim 1, wherein the internal electrodes are formed on the surface of the plastic film by printing means or vapor deposition means.