JP2733105B2 - Manufacturing method of metallized film capacitor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a metallized film capacitor such as a metallized polyethylene terephthalate film capacitor used for electronic equipment and electric equipment.

[Conventional technology]

In recent years, various processes have been streamlined and the yield has been improved in the production method of metallized film capacitors used for electronic equipment and electric equipment, and cost reduction has been achieved.

FIG. 2 shows an example of a flowchart of a conventional method for manufacturing a metallized film capacitor. Step 11 is a deposition step of depositing an electrode metal on the organic film to obtain a metallized film, Step 13 is a slitting step of slitting the metallized film to a predetermined width, Step 14 is a winding step of the metallized film, Step 15 is Pressing process for fixing the wound metalized film to the shape of the capacitor element, step 16
Is a metallicon process for forming the electrode lead portion of the metallized film, and step 17 is to stabilize the contact of the electrode lead portion by alleviating the thermal stress in the metallicon process, and to provide the metallized film with a predetermined adhesive strength and heat resistance. Step 18 is an exterior process of applying the exterior to the capacitor element to finish the product shape. Step 19 is an electrical selection process of selecting the characteristics of the product shape metallized film capacitor based on the total capacitance, dielectric loss tangent and withstand voltage. It is.

[Problems to be solved by the invention]

However, in the above manufacturing process, expansion and contraction of the metallized film and increase in residual stress cannot be prevented, and the characteristic yield of the obtained metallized film capacitor is 94%.

A factor that lowers the yield of characteristics is that a large amount of thermal stress is applied to the metallized film by the vapor deposition step (step 11) to obtain a metallized film. In the pressing step (step 15) and the metallikon step (step 16), thermal stress is applied, and the stress remains. The purpose of the aging step (step 17) is to alleviate the residual stress and the like caused by the thermal stress.
11) The residual stress caused by thermal stress cannot be reduced. When the fixed state of the capacitor element is not uniform, the metallized film expands and contracts, and the residual stress increases.
As described above, the increase in the stress of the capacitor element causes a decrease in the yield of the metallized film capacitor characteristics.

As described above, the conventional method for manufacturing a metallized film capacitor cannot prevent the expansion and contraction of the metallized film and the increase in the stress of the capacitor element due to the residual stress, thereby improving the yield of the electrical characteristics of the metallized film capacitor. Is very difficult.

An object of the present invention is to provide a method of manufacturing a metallized film capacitor capable of reducing expansion and contraction and residual stress of a metallized film, preventing an increase in stress of a capacitor element, and improving the yield of electrical characteristics.

[Means for solving the problem]

The method for producing a metallized film of the present invention is characterized in that, before the winding step of the metallized film obtained by depositing the electrode metal on the organic film, the temperature is 40 ° C. or higher and the glass transition temperature of the organic film is 10 ° C. Set the temperature below the high temperature and set the time to 6
A heat treatment step of at least 60 hours but not more than 60 hours is added.

[Action]

The manufacturing method of the metallized film capacitor of the present invention comprises:
The expansion and contraction and residual stress of the metallized film, which are subjected to a great deal of thermal stress in the vapor deposition process, can be reduced by the above-mentioned heat treatment process, and an increase in the stress of the capacitor element can be prevented.

〔Example〕

FIG. 1 is a flowchart showing steps of a method for manufacturing a metallized film capacitor according to the present invention. Step 1
Is a vapor deposition step of vapor-depositing an electrode metal on an organic film to obtain a metallized film, and the next step 2 is a heat treatment step of heat-treating the obtained metallized film. Than the glass transition temperature
The temperature should be within the range of 10 ° C. or higher and the processing time should be 6 hours or more and 60 hours or less. The subsequent steps are the same as those in the prior art. Step 3 is a slitting step of slitting the metallized film to a predetermined width. Step 4 is a winding step of the metallized film. Step 6 is a metallikon process for forming an electrode lead portion of a metallized film, and Step 7 is a step of relaxing thermal stress in the metallikon process to stabilize contact of the electrode lead portion, An aging process for imparting a predetermined adhesive strength and heat resistance to the product, Step 8 is an exterior process of applying an exterior to the capacitor element to finish the product shape, and Step 9 is a capacitance, dielectric loss tangent, and withstand voltage of the metallized film capacitor in the product shape. This is an electric sorting process for sorting characteristics obtained by integrating the above.

3 μm thick polyethylene terephthalate (hereinafter referred to as PE
T)) Metallize an organic film consisting of a film by vapor deposition of electrode metal on one side by vapor deposition process (Step 1)
A PET film is obtained, and then, in a heat treatment step (step 2), a processing temperature of 50 ° C. (glass transition temperature of PET = 69 ° C.),
Heat treatment was performed for 24 hours. In the subsequent steps, the metallized film is slit to a predetermined width in the slitting step (step 3), the metallized film is wound in the winding step (step 4), and the pressing step (step 5) is performed in the same manner as in the related art. The metallized film was hot pressed to fix it to the shape of the capacitor element. Next, metallikon process (Step 6)
The metal is sprayed to form the electrode lead portion of the metallized film, and the aging process (step 7) reduces the thermal stress in the metallikon process to stabilize the contact of the electrode lead portion, or to the metallized PET film. Aging for imparting predetermined adhesive strength and heat resistance was performed. Further, in the exterior step (step 8), the capacitor element is externally provided to obtain a product shape of a metallized PET film capacitor having a capacitance of 0.1 μF. Finally, in the electric sorting step (step 9), the metallized PET film capacitor is obtained. The combined characteristics of capacitance, dielectric loss tangent, and DC boost breakdown voltage were measured and selected.

FIG. 3 shows the dielectric loss tangent characteristics and distribution of the metallized PET film capacitor obtained in the example and the metallized PET film capacitor obtained in the conventional process as comparative examples. Compared with the metallized PET film capacitor obtained by the conventional process, the value of the dielectric loss tangent of the obtained metallized PET film capacitor is reduced, the range of variation is narrowed, the expansion and contraction of the metallized PET film is suppressed, and the It can be seen that the concentration of residual stress on the contact portion between the deposited metal and the electrode lead portion can be suppressed.

FIG. 4 similarly shows the characteristics of the DC boost breakdown voltage and the distribution state of the metallized PET film capacitor obtained in the example and the metallized PET film capacitor obtained in the conventional process as a comparative example. Compared with the metallized PET film capacitor obtained in the conventional process, the value of the DC boost breakdown voltage of the obtained metallized PET film capacitor is higher, the range of variation is narrower, and the adhesive strength between the metallized PET film layers is lower. It can be seen that it becomes uniform and the concentration of residual stress is suppressed.

Next, using the obtained metallized PET film capacitor and the metallized PET film capacitor obtained in the conventional process as comparative examples, the respective characteristic yields and overall characteristic yields in the electric sorting process are shown in the following table.

From the table, it can be seen that the overall characteristic yield of the metallized PET film capacitor is improved from 94% to 99.4%.

As a result of various experimental investigations, the temperature and time of the heat treatment process were confirmed to be able to suppress the expansion and contraction and residual stress of the metallized PET film in the vapor deposition process by performing heat treatment at a lower temperature limit of 40 ° C for 6 hours or more. Heat treatment at a temperature higher than the glass transition temperature by more than 10 ° C causes the PET film to deteriorate in a short time
It can be confirmed that the DC step-up breakdown voltage of the PET film capacitor gradually decreases.If the temperature is within 60 hours within a temperature range of 10 ° C higher than the glass transition temperature, the PET film does not deteriorate, and the metallized PET film capacitor does not progress. DC
It was confirmed that the boost breakdown voltage was not reduced.

In this example, PET (polyethylene terephthalate) was used as the organic film material of the metallized film. However, the same effect can be obtained if the organic film is generally used for metallized film capacitors such as polyphenylene sulfide and polypropylene. Obtainable. Further, in the embodiments, the description has been made using the wound type of the single-sided metallized film, but the same effect can be obtained by the laminated type of the single-sided metallized film and the wound type or the laminated type of the double-sided metallized film.

〔The invention's effect〕

The manufacturing method of the metallized film capacitor of the present invention comprises:
By adding a metallized film heat treatment process before the winding process, the characteristics of the metallized film capacitor can be improved and the variation in characteristics can be reduced to improve the characteristic yield, resulting in a significant cost reduction. To

[Brief description of the drawings]

FIG. 1 is a flowchart of a manufacturing process according to one embodiment of the present invention, FIG. 2 is a flowchart of a conventional manufacturing process, FIG. 3 is a characteristic distribution diagram of a dielectric loss tangent between the embodiment and a conventional product, and FIG.
The figure is a characteristic distribution diagram of the DC boost breakdown voltage in the example and the conventional product.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinichi Ueda 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. In company

Claims (1)

(57) [Claims] (1) Before the winding step of the metallized film obtained by vapor-depositing the electrode metal on the organic film, the temperature is set to a range of not less than 40 ° C and not more than 10 ° C higher than the glass transition temperature of the organic film. And a method of manufacturing a metallized film capacitor to which a heat treatment step of setting the time to 6 hours or more and 60 hours or less is added.