JPH02129906A - Manufacture of film capacitor - Google Patents

Abstract

PURPOSE:To realize reliable and effective manufacture by eliminating a section of a dielectric on the side of an electrode drawing edge face in preference to an electrode to expose an electrode to the edge face and simultaneously by forming an irregular edge face between dielectric layers. CONSTITUTION:A proper laser beam 2 having a wave length of at least about 0.4mum is irradiated to an end of an electrode drawing side of a film capacitor 3 whose adsorption rate against a laser beam having a wavelength of 0.4mum or below is higher in a dielectric material than in an electrode material to eliminate a dielectric section in preference to an electrode 5. The electrode 5 is exposed to an edge face and irregularity is formed between layers of lami nated dielectric 4. Since an edge face of each dielectric of an electrode drawing end side is made irregular, an edge face electrode 7 formed thereto keeps good electric contact with an electrode and attaches firmly thereto. Reliability can be thereby acquired and effective manufacture is realized.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for manufacturing a film capacitor.

(Prior Art) With the recent trend toward smaller and lighter electronic components, higher performance, and lower prices, film capacitors are also required to be smaller and lighter and have higher performance.

FIG. 6 is a diagram illustrating a conventional method for manufacturing a laminated film capacitor element, and is a cross-sectional view showing the ideal lamination of single-sided metalized films constituting a film capacitor.
2 is a single-sided metallized film having a metal film on one side, 22 is an electrode formed of the metal film on one side, 23 is a film lamination gap, and 24 is a margin portion where the electrode 22 is not formed.

In the conventional laminated film capacitor element, as shown in the figure, in order to form end electrodes, a single-sided metallized film 21 is wound in a wrap state with alternating shifts of, for example, a minimum of 0.2 m in the width direction, and the film lamination gap 23 is wound. was formed, and a contact layer made of metallicon was inserted into the gap between the lap parts to obtain electrical connection with each of the electrodes 22 and strong adhesion strength.

However, the above-described manufacturing method
1. High precision is required for winding.

If the winding accuracy is low, the wrapping state will meander, and this meandering can be avoided by narrowing the film width to make the capacitor smaller.
Or, if the thickness of the film is made thinner to increase the capacity, the problem becomes even worse, and the wrap width is usually set at 0.2
It becomes difficult to maintain m.

Figure 7 is a cross-sectional view showing this state, and if the winding accuracy is low,
As shown in this figure, it is difficult to maintain the set shift amount, that is, the wrap width ■4, and wind it, resulting in various problems such as low manufacturing yield, decreased capacity stability, high cost, and difficulty in downsizing. will occur.

On the other hand, there is a manufacturing method in which multiple wide films containing capacitor elements are wound and then cut into the width of a unit capacitor.This method is highly productive in itself, but since it does not form gaps between film laminations, the electrode drawer is not as described above. It cannot be done using this method. An alternative method is to cut a plurality of wide single-sided metallized films having capacitor elements to the width of a unit capacitor element, and then wind and laminate them, but this method still has the drawback of poor productivity.

In order to eliminate this drawback, for example, as disclosed in Japanese Patent Application Laid-Open No. 58-24933, a plurality of wide single-sided metallized films having capacitor elements are formed with arrays of through holes in the margins and wound. There is a manufacturing method that takes advantage of the fact that a film lamination gap can be obtained by cutting the rolled material at the margin.

Figures 8 to 10 are diagrams explaining the method.
5 is a margin width portion, 26 is a through hole, and other symbols refer to the explanations of the symbols up to the previous figures.

First, as shown in FIG. 8, a wide single-sided metallized film 21 on which a plurality of electrodes 22 and margin parts 24 are formed is attached to a margin width part formed by the adjacent margin parts 24. 25, a plurality of through holes 26 are arranged in the length direction, and then, as shown in FIG. A plurality of parent capacitor elements are obtained as shown in FIG. 10 by winding the capacitor elements in a staggered manner and cutting the resulting wound material at the center of the margin width section 25.

The parent capacitor element formed in this way has through-hole 2
6, a film interlayer FAX 23 is formed to ensure sufficient penetration of the contact layer as an end electrode formed of metallicon, and good and good electrical contact between the contact layer and the electrode 22. Since sufficient adhesion strength of the end electrodes can be obtained, a plurality of unit capacitor elements can be obtained at the same time by cutting at right angles to the margin direction.

However, although the above manufacturing method improves productivity, the "burr" remaining on the periphery of the through hole 26 presses the adjacent single-sided metallized film 21, resulting in
3 is crushed or the film thickness is less than 2.0 mm, the film lamination gap 2 is reduced due to the flexibility of the film.
3 is blocked, and as a result, good electrical contact cannot be obtained between the contact layer formed of metallicon and the voltage Vfi, 22. To solve this problem, Japanese Patent Laid-Open No. 63
Japanese Patent No. 76797 discloses a method for manufacturing a film capacitor in which a portion of a dielectric constituting the film on the side of the electrode extension end surface is selectively removed using plasma.

(Problems to be Solved by the Invention) However, the method using plasma has the disadvantage that the dielectric of the single-sided gold-layered film 21 deteriorates due to temperature rise during processing, and also because plasma processing is performed in a chamber. There is a problem that it lacks workability and that it is difficult to control processing speed etc. due to plasma reaction.

An object of the present invention is to provide a method for manufacturing a laminated or wound type film capacitor that solves the above-mentioned conventional problems.

(Means for Solving the Problems) The present invention achieves the above-mentioned object by providing electrode extraction for a film capacitor whose dielectric material has a higher absorption rate for a laser beam with a wavelength of 0.4 or less than the electrode material. The side end face is irradiated with an appropriate laser beam with a wavelength of about 0.4P or less to remove the dielectric portion preferentially than the electrode, thereby exposing the electrode to the end face and removing the space between each of the stacked dielectric layers. By forming the unevenness, it is possible to form an end face electrode that has good electrical contact with the exposed electrode and sufficient adhesion strength, thereby achieving the purpose.

(Function) According to the present invention configured as described above, the electrode can be easily exposed from the electrode lead-out end face of the parent capacitor element, and furthermore, the end face of each dielectric material in the electrode lead-out end face portion is formed with an uneven surface. Therefore, the end face electrode formed thereon maintains good electrical contact with the electrode and adheres with sufficient strength, so that a laminated or the same type of film capacitor can be manufactured efficiently.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention by manufacturing a multilayer film capacitor, in which 1 is an excimer laser oscillator, 2 is a laser beam, and 3 is a multilayer film capacitor. The laminated film capacitor 3 is installed in the optical path of the laser beam 2 from the excimer laser oscillator 1 so that the laser beam irradiates the electrode lead end face. In this example, the cross-sectional area of laser beam 2 is 25mm x 7w.
m, and it is possible to install a plurality of laminated film capacitors 3 in the optical path of the laser beam 2.6 Figure 2 is a processed cross-sectional view of the laminated film capacitor 3, showing a cross section perpendicular to the end face of the electrode lead. 4 is the vI@body that makes up the film, and the material is polyethylene terephthalate (
P, E, T), 5 is an electrode made of aluminum, and 6 is a margin portion.

When the wavelength of the laser beam 2 is 248 nm, the beam absorption rate of the dielectric 4 is about 97%, and the beam absorption rate of the electrode 5 is about 25%. Further, the bond energy of C-C1C-H etc. of the dielectric material 4 is about 80 k caQ/wolf to 100 k caa/moa, and the bond energy of aluminum of the electrode 5 is 55 kcad/mol+.

Therefore, when the electrode extraction end face is irradiated with a substantially uniform laser beam 2, the processing speed per 1 mof2 is:
The dielectric 4 is larger than the electrode 5.

FIG. 3 is a cross-sectional view after the processing shown in FIG. 2. The dielectric material 4 is laser-processed preferentially than the electrode 5, and is set back from the end surface of the electrode 5 leaving a margin 6. At the same time, each dielectric material 4 is
Due to the slight difference in speed of laser processing, the end faces are uneven. Therefore, by spraying metal onto this portion, a firmly connected end electrode 7 with good electrical connection is formed.

Figure 4 is a cross-sectional view of the completed capacitor element, which shows the formation direction of the rear margin after the end electrodes are drawn out on both end faces as explained in Figure 3, and then brass is sprayed to form the end electrodes 7. A unit capacitor element is obtained by cutting the capacitor in a direction perpendicular to .

FIG. 5 is a perspective view showing another embodiment, showing the main part of a method for manufacturing a single-wound film capacitor of the same type, and 8 is a wound-wound film capacitor before end face electrodes are formed. The laser beam 2 is installed in the optical path of the laser beam 2 from the excimer laser oscillator 1 so that the electrode extension end face of the wound film capacitor 8 before end face electrode formation is irradiated with the laser beam 2. A film capacitor of the same type on the right is manufactured using the same process as in Example 2, and detailed explanation thereof will be omitted.

The embodiment has been explained above using an excimer laser, which has high photon energy and can retract the dielectric 4 without being focused on a minute spot at the processing point, and can also perform quantum cutting using an ultraviolet laser. Because it is a process that utilizes

Furthermore, if the laser beam is irradiated in a pulsed manner, the thermal effects can be further reduced and the processing controllability is also excellent. Note that in the above description, it goes without saying that the laser beam may be any other laser beam as long as it has a wavelength of 0.4p or less.

(Effect of the invention) As is clear from the detailed description above, the present invention is as follows.

The wavelength is 0.41! A single-sided metallized film formed from a dielectric material made of an organic material with an absorption rate of 30% or more for a laser beam of m or less and a larger absorption rate than the electrode material and an electrode made of a metal film is laminated, and the electrode extraction side is laminated. The wavelength is about 0.4. The following laser beam is irradiated to remove the dielectric portion on the end face side of the electrode extension preferentially than the electrode, thereby exposing the electrode to the end face and at the same time forming an uneven end face between each dielectric layer. This makes it possible to form end-face electrodes that make good electrical contact with the electrodes and adhere with sufficient strength, resulting in the effect that reliable multilayer film capacitors can be manufactured efficiently and easily.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the main steps of an embodiment of the present invention, Fig. 2 is a processed sectional view, Fig. 3 is a sectional view after processing of Fig. 2,
Figure 4 is a sectional view of a capacitor element, Figure 5 is a perspective view showing the main steps of another embodiment, Figure 6 is a sectional view showing the ideal structure of a conventional multilayer film capacitor element, and Figure 7 is a conventional Cross-sectional view of a laminated film capacitor element being manufactured by the method,
FIG. 8 is a perspective view showing a conventional single-sided metalized film provided with through holes, and FIG. 9 is a cross-sectional view of the single-sided metalized film laminate shown in FIG. 8 before cutting. 1... Excimer laser oscillator, 2... Laser beam, 3... Multilayer film capacitor, 4
...Dielectric material, 5...Electrode, 6...Margin part, 7...End face electrode, 8...Wound film capacitor. Figure 10 shows the result of cutting in Figure 9 Patent applicant Matsushita Electric Industrial Co., Ltd. Saya Ward A, Figure ○

Claims (2)

[Claims] (1) In a method for manufacturing a film capacitor in which one-sided metallized film is laminated, a dielectric material made of an organic material with an absorption rate of about 30% or more for a laser beam with a wavelength of about 0.4 μm or less, which is larger than the electrode material. By laminating a plurality of single-sided metalized films consisting of a body and an electrode formed by metalizing one side of the film, and irradiating a laser beam with a wavelength of about 0.4 μm or less to the electrode extraction end face on the side, the above-mentioned method can be achieved. A method for producing a film capacitor, comprising removing the dielectric material preferentially over the electrodes, and forming end face electrodes afterward. (2) The method for manufacturing a film capacitor according to claim (1), wherein the single-sided metalized film is wound and laminated.