JPS62117311A - Laminated film capacitor - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a laminated film composite used in electronic equipment and electrical equipment.

Conventional technology In recent years, with the advancement of electronic component mounting technology, the chipping and miniaturization of electronic components has progressed rapidly, and film capacitors have also been chipped and miniaturized. I'm looking for something. L
Since the IL dielectric constant of the heavy resin Fufilno is about two orders of magnitude smaller than that of dielectric materials such as ceramic capacitors and tantalum electrolytic capacitors, it is disadvantageous for miniaturization.

Figures 7 and 8 show the element structure of film-condensation. Figure 7 shows the case where double-sided metalized film is used, and Figure 8 shows the case where single-sided metalized film is used. . In the figure, 1 is a double-sided metallized film, 2 , 2
-1, 2-2 are M-coated electrodes, 3 is a dielectric film, 4-
1.4-2 is sprayed metal, 5 is single-sided metalized Filno 1.6
- Vapor deposited electrodes 2, 2-1, 2-2 and sprayed metal 4-1, 4
-2 is the connection part, 7 is the vapor deposition margin part, and 8 is the protruding part of the metallized film.

Regarding the miniaturization of Filno capacitors, 3
・The following three points are important.

1. Make the dielectric film thinner.

2. Reduce the exterior volume.

3. Reduce non-capacitive parts.

However, regarding 1 above, the current film thickness is 2 μm f4
Holly ethylene terephthalate film is on the market, but mass production of thinner films results in poor yields and high prices. It's a trench. Above 2.
Reducing the exterior material of the capacitor element is undesirable because it impairs the heat resistance, moisture resistance, and long-term reliability of the capacitor element. Regarding 3 above, the non-capacitance portion refers to a portion that does not contribute to the formation of capacitance, such as the vapor deposition margin portion 7 and the sprayed metal portion 4-1° shown in FIGS. 7 and 8. 4-2 and the portion 8 where the metallized film protrudes, etc. correspond to this. If the volume of the capacitor is not small, the volume of the non-capacitance part will not be a problem as it will account for a small proportion of the total volume, but if the volume of the capacitor is small, the volume of the non-capacitance part will take up a certain amount of volume to draw out the electrodes. Since it requires
The ratio of the non-capacitance portion to the total area becomes extremely large. As described above, the non-capacitance portion is one of the major factors hindering miniaturization.

However, as laminated film capacitors are made smaller, capacitance accuracy decreases. The capacitance accuracy is greatly influenced by the width accuracy of the counter electrode, and the width accuracy of the counter electrode is determined by the dimensional accuracy in the film width direction during vapor deposition, the slit M degree of the film, and the accuracy in the film width direction during lamination. 7th grade
This is because the width of the opposing electrode would have to be made thinner if it were converted to 1;

Next, the electrode extension section will be described. The electrodes of the laminated film capacitor are drawn out by spraying a metal or applying a dielectric paint to the protruding portion 8 of the metallized film. Here, the contact state between the vapor deposited electrodes 2-1.2-2 of the metallized films 1 and 5 and the sprayed metal etc. 4-1.4-2 is a factor that greatly influences the characteristics of the capacitor element. If this contact condition is poor, not only the element characteristics will deteriorate, but also the vapor deposited electrode 2-1, 2-2 and the sprayed metal 4-1,
If 4-2 separates, the capacitor element may even be lost, so this contact portion must have sufficient strength both electrically and mechanically. In order for this contact part to maintain sufficient strength, it is shown in Figures 7 and 8.
-2 penetrates into the gap between the metallized films to form the deposited electrodes 2 and 2-1.

Connection part 6 with surface 2-2 (this state is called surface connection)
need to be maintained. If sprayed metal 4-1 as shown in Figure 9
．． If 4-2 does not penetrate into the gap between the metallized films and only connects to the end of the vapor-deposited electrode 2 (this state is called a line connection), the contact area is extremely small and the contact area is extremely small. It becomes a weak connection. If a thin film is used here, the gap between the films becomes narrow due to the thin thickness, and the so-called stiffness of the film is weak, so the gap between the films that should have been closed may be closed due to the deformation of the film itself. Because of this, it is very difficult to obtain the above-mentioned surface connection state.

In the conventional technology, in the case of such a structure, as shown in FIG. 10, by repeatedly providing protruding deformation parts 1o in the film thickness direction 61. It has been proposed to widen the gap so that the sprayed metal can more easily penetrate between the films.

Problems to be Solved by the Invention As stated above, in conventional multilayer film capacitors, the non-capacitance portion occupies a large proportion of the volume.
This is disadvantageous for miniaturization, and as mentioned earlier, the smaller the size, the more difficult it is to achieve capacitance accuracy.As for the electrode lead-out part, even with the method of providing the protrusions mentioned above, surface connection between the sprayed metal and the vapor-deposited electrode is difficult. can only be obtained near the protrusions, so even though it is a surface connection, there are problems such as its strength is weak electrically and mechanically, and a certain amount of volume is required for the protrusions. Ta.

In view of the above drawbacks, the present invention eliminates the vapor deposition margin and the protruding portion of the metallized film from a multilayer film capacitor, thereby reducing the volume ratio occupied by the non-capacitance portion compared to the conventional one, thereby making the capacitor more compact. It is extremely advantageous to reduce the electrostatic field due to miniaturization. J, We provide a small multilayer film capacitor with excellent capacitance accuracy and element characteristics, with the aim of preventing the decrease in M degree and making the connection between the sprayed metal and the vaporized A/electrode a stronger surface connection. It is something to do.

A further means for solving the problem In order to achieve the above object, the film capacitor of the present invention consists of double-sided metallized films that are folded/folded into a bellows shape and laminated, and the outer surface of the folded portion is laminated. Electrode pull 1111
.about. section is formed.

′! ! Using the capacitor obtained in this way as a base material,
A multilayer film capacitor may be obtained by cutting and cutting by an appropriate method such as laser irradiation, water jet, etc. The direction in which the twisted double-sided metallized film is folded into a bellows shape may be in the length direction of the film or in the width direction of the film.

Effect With the above-described configuration, the laminated film capacitor of the present invention has the vapor-deposited electrodes 2-1 and 2-2 of the double-sided metallized film 1.
Exposed to the outside at the folded fold l~ part [5,
In addition, the film thickness is 31%, and insulation from the electrode makes it inconvenient to protrude the metallized film 1-7 of the electrode drawer and the evaporation margin, so conventional lamination) , compared to the f-lume condenser [7] and is very small in size.
Since the surface connection between the electrode and the sprayed metal etc. is maintained reliably, the device characteristics are very good1.Also, in the capacitor of the present invention, the width accuracy of the opposing electrode is the same as the dimensional accuracy when cutting from the middle of the month, or when it is not cut. In the case of double-sided metallized Filno, the slitting accuracy is only 1:.

Therefore, it is not affected during vapor deposition or lamination, and the capacitance accuracy is very good.

Example Examples of the present invention will be described below.

Figures 1 and 2 show a film capacitor according to an embodiment of the present invention. The structure 1-7 is a double-sided metallized film, and this double-sided metalized film 109,-7 is folded into a bellows shape at predetermined intervals in the longitudinal direction of the film. On the outer surface of the folded part of the twisted double-sided metallized film 1o, an electrode drawer 7 part 13-
1.13-2 is formed.

Next, a specific example will be given and explained.

As the double-sided metallized film, a 2 μm thick poly-ethylene terephthalate film with aluminum vapor-deposited on both sides was used. As shown in Figure 3, this double-sided metallized film is folded back in the length direction of the film, and the width is 6 cylinders at a time.
] and folded it into a bellows shape 1,000 times. In addition, in FIG. 3, 14-f.

14-2 is an L-shaped jig for folding, 15 is a feed roller, 16 is a spring, and 17 is a case into which the folded double-sided metallized film 10 is pushed. Zinc was thermally sprayed on the folded part (0.6 ran on each side). The capacitor base material thus obtained was cut with a cutting saw to a width of ESm to obtain a capacitor. As a comparative example (A), We also prototyped a capacitor with a laminated single-sided metallized film structure as shown in Figure 8.

This single-sided metallized film has a film width of 7°srMn,
10' --- Vapor deposition margin width is 1 cylinder. Opposing width when stacking trenches is 5
M, the width of the protrusion of the single-sided metallized film klO,
5rrvn! ~is. 1,
After stacking 1,000 pieces of film, one side of the film was metallized, and zinc was thermally sprayed onto the protruding 7 parts of the film on each side, and the capacitor was cut into 5 cylinders with a cutting saw.

Furthermore, in Comparative Examples (B) and 1-, a protruding deformation in the film thickness direction was created on the edge of the single-sided metallized film on the side without the vapor deposition margin by the same method as in Comparative Example ^). Addition to the capacitor element is -7.7. Each of the projections has a size of about 0.5fi in the film width direction, length direction, and thickness direction, and is repeatedly provided at a two-tone pitch in the length direction of the film. Eggplant, capacitor of the present invention and comparative example (20 lots for both Al and (B), 1 each
,000 pieces were prototyped.

Table 1 shows the results of measuring the average capacitance, average dielectric loss tangent, capacitance failure rate, and average device volume of the laminated film 1 and the capacitor manufactured as described above. In addition, the capacitance failure rate is based on the electrostatic field outside the +6 range centered on the average capacitance sewing! 11 is shown as [7 primes I11 The number of primes is a percentage of the total.

Table 1Furthermore, 50 of each of the three types of prototype capacitors were subjected to a charge/discharge test. The results are shown in FIG. The charging and discharging tests were conducted under the following conditions: back capacitor capacity t1 tiF tN pressure 150 VDCv charging/discharging resistance 1Ω.

From the results shown in Table 1, it can be seen that the capacitor of the present invention is the comparative example (
5), has almost the same capacity as (B), but the element volume is about 4
It has been reduced by 6q6. This is because, as mentioned above, there is no vapor deposition margin or protruding portion of the metallized film inside the device, so it can be extremely downsized. Furthermore, the capacitor of the present invention has an extremely low capacitance defect rate compared to Comparative Examples (A) and (B). As mentioned above, this is Comparative Example (8)
, (B), the capacitance accuracy varies greatly depending on the width accuracy of the opposing electrode, but the width of the opposing electrode is greatly affected by the evaporation dimensional accuracy, slit accuracy, and lamination accuracy. The rate is large. However, since the capacitor of the present invention does not require the above-mentioned precision as described above, the defective rate is low. Furthermore, as shown in FIG. 6, the capacitor of the present invention exhibits better charging and discharging characteristics than the comparative example. This indicates that in the capacitor of the present invention, the vapor deposited electrode and the sprayed metal have a stronger connection than in the comparative example.

In addition, in the present invention, the double-sided metallized film 10 may be folded back in a bellows shape in the width direction of the film as shown in rt1 FIG. 4. In FIG. 4, 18 is a roller that creates bellows-shaped folds in the width direction of the double-sided metallized film 10, 19 is a roller that folds the film along the creases formed by the roller 18, and 20 is a take-up roller. be.

134-In addition, when the double-sided metallized film 1o is folded to form an element as shown in FIGS. 3 and 4, electrode extension parts are formed on the end faces of the folded laminate to form the finished product. However, when using a double-sided metallized film 10 of a size that allows a large number of elements to be obtained from one film,
After folding to form an electrode extension part, it may be cut to a predetermined size. An example of the cutting method is shown in Fig. 6.
b) is a case where the process is performed using a laser beam, and (C) is a case where the process is performed by cutting. In addition, 21 is the capacitor base material,
22 is a fountain nozzle, 23 is a laser light source, and 24 is a cutting blade.

Effects of the Invention As described above, the laminated film capacitor of the present invention has a structure in which double-sided metallized films are laminated by folding them into a bellows shape, and then electrode extension portions are formed on the folded portions by metal spraying or conductive paint. Because
This is a multilayer film 14-base film capacitor that is much smaller than conventional capacitors, has good capacitance accuracy, and excellent element characteristics, and can be miniaturized and made into chips, resulting in extremely large industrial effects.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a capacitor according to an embodiment of the present invention;
Fig. 2 is a cross-sectional view of the same capacitor, Fig. 3 is a perspective view showing an example of the method of folding the film in the length direction in the manufacturing process of the capacitor of the present invention, and Fig. 4 is an example of the method of folding the film in the width direction. FIG. 6 is a perspective view showing an example of the cutting method for obtaining the capacitor of the present invention by cutting, and FIG. 6 shows the results of a charge/discharge test for the capacitor of the present invention and each comparative example. Figure 7 is a cross-sectional view of a conventional multilayer film capacitor using a metalized film on both sides, Figure 8 is a cross-sectional view of a conventional multilayer film capacitor using a metalized film on one side, and Figure 9 is a cross-sectional view of a conventional multilayer film capacitor using a metalized film on one side. FIG. 10 is a cross-sectional view showing a line connection between a vapor-deposited electrode and a sprayed metal in a laminated film capacitor. FIG. 10... Double-sided metallized film, 12-1.12
-2... Vapor deposition electrode, 13-1, 13-2...
...Electrode extraction part. Name of agent: Patent attorney Toshio Nakao and 1 other person-7
ζ- To ゝC Castle - Figure 3 Figure 5 (C Figure 7 Figure 9 Figure 10

Claims (3)

[Claims] (1) A multilayer film capacitor characterized in that double-sided metallized films are stacked by folding them into a bellows shape, and an electrode extension portion is provided on the outer surface of the folded portion. (2) The laminated film capacitor according to claim 1, wherein the double-sided metallized film is folded back in the longitudinal direction of the film to form a bellows shape. (3) The laminated film capacitor according to claim 1, wherein the double-sided metallized film is folded back in the width direction of the film to form a bellows shape.