JPS6386412A - 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) With the rapid advancement of semiconductor technology, the wave of microelectronics is rapidly permeating all industries. Capacitors are no exception.

The capacitance of a capacitor is proportional to the dielectric constant and electrode area, and inversely proportional to the distance between the electrodes. Therefore, the basis for miniaturizing capacitors is to make the dielectric thinner.

The goal is to increase the dielectric constant, and miniaturization of film capacitors largely depends on plastic film molding technology.

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, inorganic materials have a higher dielectric constant than organic polymers, but
Since it is difficult to form into a thin film, it has the disadvantage that the capacitance cannot be large enough considering the dielectric constant, and processing costs are high because it requires steps such as coating and baking.

Therefore, in order to solve these conventional drawbacks, the present invention has a thin dielectric film and a large 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 three 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. A conductive metal layer (2) is formed on an organic polymer film substrate (1) (FIG. 1) by vapor deposition, ion plating or sputtering (FIG. 2). At that time, in the longitudinal direction of the film.

Oil margin method, water-soluble margin method, tape margin method, or vapor deposition mask method is used to deposit the lower electrode according to the required design.

On this lower electrode (2), an organic polymer thin film N (3) is formed with an arbitrary width according to the required pattern so that a non-printed part remains at the center of each lower electrode (Fig. 3). ). The organic polymer thin film layer has a dielectric loss tangent of 1% or less when measured at +1 kHz.

A thermoplastic resin having a film thickness in the range of 0.1 to 0.7 μm.

It is preferable to use thermosetting resins and mixtures of both.

However, if the film thickness is 0.1 μm or less, sufficient electrical insulation resistance cannot be obtained, and if the film thickness is 0.7 μm or more, a large capacitance per cross-sectional area cannot be obtained, which is not practical. For example, thermoplastic resins include polystyrene, polyethylene, polyamide, polyimide, polysulfone,
Polypropylene-based.

Examples include polyarylate type and polyester type.

Thermosetting resins include urea, melamine, phenol, epoxy, and unsaturated polyester.

Examples include alkyd type and urethane type. usually.

Preferably, a polyester resin is used, but if heat resistance is required, a polyamide resin is used.

It is preferable to use polyimide or polysulfone.

Although any method may be used to form the organic polymer layer, 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, an oil margin is used to form a pattern in order to form a film on the organic polymer thin film layer. As a thin film dielectric layer.

Examples include zinc sulfide, lead oxide, silicon oxide, titanium oxide, yttrium oxide, etc., and it is preferable to use zinc sulfide. Moreover, 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, the film itself will crack, 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 a pattern using oil margins. Also,
If higher electrical insulation resistance and dielectric properties are desired, a thin film dielectric layer (4) and a top electrode (5) may be added as necessary.
An organic polymer thin film layer may be added between the two.

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 unit capacity, cut out a wound capacitor or unit capacity by cutting it to any length.

A chip type capacitor is obtained by MH.

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.

In manufacturing a thin film dielectric material for a capacitor, which is formed by successively laminating conductive metal layers as an upper electrode, an oil margin method is used to pattern the thin film dielectric layer and each layer of the upper electrode.

Continuous mass production becomes possible, which is industrially beneficial.

Moreover, it has become possible to manufacture with high yield.

(Example) The present invention will be specifically described below by showing two examples and referring 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 the width direction of this film in a pattern with a pitch of 18 m and a radius of 4H. , hydroxypropyl cellulose (TCI-
E, P, Tokyo Kasei) was formed to a thickness of 1 μm in the longitudinal direction of the film by gravure printing. Next, apply A to the entire surface of this.
0.06 by vacuum evaporation method using I as the lower electrode (2)
The water-soluble polymer layer and the AI on the water-soluble polymer layer were simultaneously washed out by washing with water, and the water was evaporated in a continuous drying oven (Fig. 2). Next, an organic polymer thin film layer (
As for 3), a non-printing portion with a width of 2R is left at the center of each lower electrode, and a non-printing portion with a width of 2N is left at the center of the non-evaporated portion of the lower electrode.

A polyester resin (Vylon 200. Toyobo) was formed to a thickness of 0.3 μm in the longitudinal direction of the film by gravure printing (Figure 3). Next, the zinc sulfide thin film dielectric layer (4) is coated with an RF bio-ion plate using an oil margin so that both ends of this non-printed area are hidden and the film is formed on the organic polymer layer. Formed by the ting method (
Figure 4).

That is, argon is introduced into the Pelger and the degree of vacuum is 7.
X maintained at 10-'Torr, voltage 2kV, frequency 1
While applying a 3.56 MHz high frequency electric field of 100 W,
The zinc sulfide evaporation base material is heated and evaporated with an electron gun to 0.5
μm was formed. However, the evaporation base material used was one obtained by press-molding fine powder with a purity of 99.99% and performing vacuum sintering at 800° C. for 6 hours. and.

On top of this, add 2 ml of the lower electrode exposed part and
AI was vacuum-deposited to a thickness of 0.06 μm as the upper electrode (5) using an oil margin so as to hide a total of 4 cranes (Figure 5). Next, by a slitter.

The center portion of each lower electrode and the center portion between the lower electrodes were cut and 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 button), 80nF (Example 4), 1
00 nF (Example 5) A capacitor element was formed.゛External electrodes are formed on these capacitor elements by zinc spraying, and then resin molded.

Capacitance (measured at 1kHz), electrical insulation resistance (measured at 30V) and yield rate were measured. The results are shown in Table 1. However, the yield rate is expressed as a percentage of 100 samples each having an electrical insulation resistance of 5×10 9 Ω or more.

(Effect of the invention) According to the present invention, first-order effects 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 higher yield.

In other words, by using the oil margin method, the process is simplified and costs can be significantly reduced compared to conventional methods. At the same time, it has become possible to stably produce products with a low dielectric loss tangent (electrical insulation resistance 2) and a high yield rate. Compared to the metallized film material, handling in the manufacturing process is almost the same, and a completely new and superior thin film dielectric material for capacitors can be industrially advantageously manufactured.

[Brief explanation of the drawing]

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 (1)

[Claims] An organic polymer film is used as a support substrate, a conductive metal layer is provided as a lower electrode on at least one surface of the support substrate, and a non-evaporated portion is present in the longitudinal direction of the polymer film as required. Form the electrode in this manner, and then apply a thin organic polymer film layer on top of it with an arbitrary width so that a non-printed part remains in the center 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 an upper electrode is formed on the organic polymer thin film layer, excluding the exposed portion of the lower electrode. When manufacturing a thin film dielectric material for a capacitor formed by forming a desired pattern on a portion with an arbitrary width, a vapor deposition method or an ion plating method is used to form a lower electrode, a thin film dielectric layer, and an upper electrode. Alternatively, a thin film dielectric material for capacitors is used, which uses a sputtering method, an oil margin method for patterning the thin film dielectric layer and the upper electrode, and a coating method or printing method for forming the organic polymer thin film layer. Production method.