JPS6386413A - Manufacture of thin film dielectric material for capacitor - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a thin film dielectric material for capacitors, and is useful for industrially mass producing small and lightweight film capacitors. purpose.

(Prior Art) (Problem to be Solved by the Invention) The capacitance of a capacitor is proportional to the dielectric constant of the dielectric and the area of the electrodes, and inversely proportional to the distance between the electrodes. Therefore, in order to increase the capacitance of a capacitor, it is necessary to increase the dielectric constant of the dielectric or reduce the thickness of the dielectric.

Conventional film capacitors use the organic polymer film itself as a dielectric, so the dielectric constant is low at around 2 to 5. Also, due to technical issues, the film thickness can only be reduced to around 2 μm. it is conceivable that. Therefore, in order to increase the capacitance, it was necessary to wind the film in multiple layers.

In addition, capacitors manufactured by coating organic polymers on the top of the conductor have recently been developed, but the thickness of the coating film is 1 μm.
If the thickness is reduced to less than m, problems will arise in electrical insulation.

On the other hand, although inorganic materials have a higher dielectric constant than organic polymers, they have the disadvantage of not being able to provide a large capacitance relative to their dielectric constant because they are difficult to form into thin films.
Processing costs are high because it involves processes such as coating and firing.

Therefore, in order to solve these conventional drawbacks, the present invention increases the thickness of the dielectric film and increases the dielectric constant.

The aim is to manufacture capacitors with good insulation.

(Means for Solving the Problems) As a result of intensive research to develop an industrially useful manufacturing method for the thin film dielectric material for capacitors, the present inventors have discovered that an organic polymer film can be used as a support substrate. A conductive metal layer as a lower electrode, an organic polymer thin film layer, a thin film dielectric layer, and a conductive metal layer as an upper electrode are sequentially laminated on at least one surface according to the required pattern of each layer. The invention was achieved.

The present invention will be specifically described below with reference to nine drawings.

First, the lower electrode is placed in the longitudinal direction of the organic polymer film.
The electrode is formed so that a non-evaporated portion exists according to the necessary design. Examples of the conductive metal layer include aluminum, zinc, gold, etc., and aluminum is preferably used. However, the longitudinal direction of the film means the direction in which the film is wound.

The width direction of the film means the direction intersecting the longitudinal direction. On an organic polymer film substrate (1) (FIG. 1), a water-soluble polymer layer is formed in a desired design in the longitudinal direction of the film by a coating method or a printing method. The water-soluble polymer layer includes polyacrylic acid sorter, polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose,
Examples include polyethylene oxide, polyvinylpyrrolidone, polyacrylic acid amide, etc., and cellulose-based materials are preferably used. Although any method may be used for forming the film, it is preferable to use a gravure printing method. Next, cover the entire surface of this.

A conductive metal layer is formed by a vapor deposition method, an ion plating method, or a sputtering method, and the water-soluble polymer layer and the conductive metal layer thereon are washed out with water to form a lower electrode (2). ), or
Instead of this water-soluble margin method, the lower electrode may be formed using a tape margin method, an oil margin method, or a vapor deposition mask method. However, the tape margin method in this case is a method in which a fluorine-based film with a low coefficient of thermal expansion is fed in synchronization with the processing speed of the substrate, so that it adheres to the substrate and prevents film formation on that area. It is something. The vapor deposition mask method is a method in which a negative pattern mask is closely attached to a substrate to form a pattern.The mask material is a material with a low coefficient of thermal expansion such as glass, metal, or graphite, which can be etched. Those with holes and patterns are used.

Then, on this lower electrode (2), an organic polymer thin film layer (3) is formed with an arbitrary width according to the required pattern so that a non-printed part remains at one end of each lower electrode (
(Fig. 3), the organic polymer thin film layer has a dielectric loss tangent of 1% or less when measured at 1kHz, and a film thickness of 0.1 to 0.7μ.
It is preferable to use thermoplastic resins, thermosetting resins, and mixtures of both in the range of m. However, if the film thickness is 0.1 μm or less, sufficient electrical insulation resistance cannot be obtained;
m or more, it is not practical because a large capacitance per cross-sectional area cannot be obtained. For example, thermoplastic resins include polystyrene, polyethylene, polyamide, polyimide, polysulfone, polypropylene, polyarylate, polyester, etc., and thermosetting resins include urea.

Melamine-based, phenol-based, epoxy-based, unsaturated polyester-based, alkyd-based, urethane-based resins, etc. are used.Usually, it is preferable to use polyester-based resins, but if heat resistance is required, polyamide-based resins are used. It is preferable to use polyimide, polysulfone, or polysulfone. Any method may be used to form the organic polymer layer, but it is preferable to use a coating method or a printing method.

Thereon, a thin film dielectric layer (4) is formed using a vapor deposition method, an ion plating method, or a sputtering method (FIG. 4). At this time, in order to form a film on the organic polymer thin film layer, a pattern is formed using a vapor deposition mask or tape margin. Examples of the thin dielectric layer include zinc sulfide, lead oxide, silicon oxide, titanium oxide, yttrium oxide, etc., and zinc sulfide is preferably used.

The film thickness is preferably in the range of 0.1 to 0.8 μm. however.

If the film thickness is 0.1 μm or less, sufficient electrical insulation resistance cannot be obtained, and if the film thickness is 0.8 μm or more, cracks will occur in the film itself, resulting in a decrease in yield rate.

Then, a conductive metal layer as an upper electrode is formed thereon using a vapor deposition method, an ion plating method, or a sputtering method (FIG. 5).

At that time, in order to form a film on parts other than the exposed part of the lower electrode,
Form the pattern using a deposition mask or tape margin. In addition, if higher electrical insulation resistance and dielectric properties are desired, a thin film dielectric layer (4
) and the upper electrode (5) may include an organic polymer thin film layer.

Then, by cutting it out with a slitter (6)
, a thin film dielectric material for capacitors is obtained (Fig. 6). In order to obtain the desired capacitance unit, we cut out a wound capacitor or unit capacitor by cutting it to any length.

A chip-type capacitor is obtained by laminating layers.

In the above, an organic polymer film is used as a support substrate.

A conductive metal layer as a lower electrode, an organic polymer thin film layer, and a thin dielectric layer on at least one surface thereof.

When manufacturing thin film dielectric materials for capacitors, which are made by sequentially laminating conductive metal layers as upper electrodes, continuous mass production is possible by using a mask method to pattern the thin film dielectric layers and the upper electrode layers. Therefore, industrially,
It has become possible to produce products that are both profitable and have a high yield.

(Example) The present invention will be specifically explained below by showing an example with reference to the drawings.

Examples 1 to 5 A polyester film with a film thickness of 6 μm was used as the support substrate (1) (Fig. 1), and a water-soluble polymer layer was formed in a pattern of 18 fl pitch and 2 fl width in the width direction of this film. , hydroxypropyl cellulose (TC
I-E, P., Tokyo Kasei) was formed to a thickness of 1 μm in the longitudinal direction of the film by gravure printing. Next, a lower electrode (2) of AI was applied to the entire upper surface using a vacuum evaporation method.
06 μm was deposited, the water-soluble polymer layer and A1 on the water-soluble polymer layer were washed out at the same time by washing with water, and the water was evaporated in a continuous drying oven (FIG. 2). Next, as an organic polymer thin film layer (3), lin,
Then, the polyester resin was printed in the longitudinal direction of the film using a gravure printing method so that a non-printed part with a total width of 2 m1 remained in the non-deposited part of the lower electrode adjacent to it.
Byron 200゜Toyobo) was formed to a thickness of 0.3 μm (third
figure). Next.

Hide both ends of this non-printing part IN, create a tape margin so that it can be formed into a film on the organic polymer layer, and use this to cover the zinc sulfide thin film dielectric layer (4) on the RF bio-ion plate. (Fig. 4), that is, argon was introduced into the Pel jar and the vacuum degree was 7X.
Maintain at 10-'Torr.

While applying a high frequency electric field of 100 W with a voltage of 2 kV and a frequency of 13.56 MHz, the zinc sulfide evaporation base material was heated and evaporated with an electron gun to form a 0.5 μm thick film. However, the evaporation base material is press-molded from fine powder with a purity of 99.99%, and
The material that had been vacuum sintered at ℃ for 6 hours was used. Then, on top of this, there is one exposed lower electrode part and one part on its resin coated side.
A tape margin was made to hide a total of 21 m, and using this tape margin, AI was vacuum-deposited to a thickness of 0.06 μm as the upper electrode (5) (Fig. 5). Next, a slitter was used to cut the portion between each lower electrode exposed portion and the non-evaporated portion of the lower electrode, and the resulting material was wound 6) once to obtain a thin film dielectric material for a capacitor.

This thin film dielectric material for capacitors is passed through an element winding machine,
Design capacitance 20nF (Example 1), 40nF (Example 2), 60nF (Example 3), 80nF (Example 4),
A 100 nF (Example 5) capacitor element was formed. External electrodes are formed on these capacitor elements by zinc spraying, and then resin molded.

The capacitance (measured at 1 kHz), electrical insulation resistance (measured at 30 mm), and yield rate were measured. The results are shown in Table 1. However, 1 yield rate is expressed as a percentage of 100 samples each having an electrical insulation resistance of 5 x 10''Ω or more.

Table 1゜ (Effect of the invention) According to the present invention, the ninth-order effect can be obtained.

(1) Compared to conventional metallized film capacitors, thin film dielectric materials for capacitors that are significantly smaller in size can be produced industrially and inexpensively.

(2) Compared to conventional thin film capacitors, thin film dielectric materials for capacitors with high electrical insulation resistance and small dielectric loss tangent can be manufactured with a high yield.

In other words, by using mask methods such as the tape margin method and the vapor deposition mask method, the process is simplified compared to conventional methods, making it possible to significantly reduce costs. At the same time, it has become possible to stably manufacture products with a low dielectric loss tangent and a high yield rate per electrical insulation resistance. The thin film dielectric material produced according to the present invention has a
A completely new and excellent thin film dielectric material for capacitors, with almost no changes in the manufacturing process.

It can be produced industrially with advantage.

[Brief explanation of the drawing]

FIGS. 1 to 5 are cross-sectional views showing an embodiment of the present invention. 1 Organic polymer film substrate 2 Lower electrode 3 Organic polymer thin film layer 4 Thin film dielectric layer 5 Upper electrode 6 Cutting position

Claims (2)

[Claims] (1) An organic polymer film is used as a support substrate, and a conductive metal layer as a lower electrode, an organic polymer thin film layer, a thin film dielectric layer, and a conductive metal layer as an upper electrode are sequentially formed on at least one surface of the organic polymer film. When manufacturing thin film dielectric materials for capacitors, which are laminated according to the required pattern of each layer, the lower electrode, thin film dielectric layer, and upper electrode are formed by vapor deposition, ion plating, or sputtering. Production of a thin film dielectric material for capacitors, characterized in that a tape margin method or a vapor deposition mask method is used to form a pattern for a dielectric layer and an upper electrode, and a coating method or a printing method is used to form an organic polymer thin film layer. Method. (2) Form the lower electrode in the longitudinal direction of the organic polymer film so that there is a non-deposited part according to the necessary design, and form the organic polymer thin film layer so that the non-printed part remains at one end of the lower electrode. A thin film dielectric layer is formed on the organic polymer thin film layer with a width narrower than that of the organic polymer thin film layer, and the upper electrode is formed on the exposed portion of the lower electrode. 2. The method of manufacturing a thin film dielectric material for a capacitor according to claim 1, wherein the thin film dielectric material for a capacitor is formed in a portion other than the above portion with an arbitrary width according to a required pattern.