JPH04287307A - Manufacture of surface mounting type laminated film capacitor - Google Patents

Abstract

PURPOSE:To prevent the deformation of a metallized plastic film forming a laminated body by performing the heat treatment to be performed to the laminated body at a temperature near the melting point of the film main body of the metallized plastic film. CONSTITUTION:A laminated body 2 is formed in such a way that, after a PPS film is wound around a large-diameter drum 1 several times as a protective film 4, a pair of metallized PPS films are put on the film 4 in a laminated state and the PPS film is again wound around the drum 1 on the metallized PPS films several times. Then aluminum metallicon layers 3 are formed on both faces of the laminated body 2 by flame-spraying aluminum from both sides of the drum 1. Then mother elements 5 are obtained by segmenting the laminated body 2 from the drum 1. Each sliced element 5 is formed to one stick-like shape by heating the element 5 at 270 deg.C which is close to the melting point of the PPS film while a prescribed pressured is applied to the element 5.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a surface-mounted multilayer film capacitor among multilayer film capacitors, and particularly to technical improvements for improving heat resistance.

0002

[Prior Art] Generally, in the production of multilayer film capacitors, a metallized plastic film with metal electrodes formed on the surface of the plastic film is laminated and wound around a large-diameter drum to form a laminate. A sprayed metal layer is formed on both end faces of the laminate, and the temperature is further increased from 120°C to 15°C.
After heat-treating the laminate at 0°C, cut the laminate,
A capacitor element is formed, a lead wire is welded to this capacitor element, and finally, an undercoat and an exterior coat are applied to complete the capacitor.

On the other hand, among multilayer film capacitors, surface-mount type multilayer film capacitors are completed products without being coated because they are surface-mounted on a substrate. That is, in manufacturing a surface-mount type multilayer film capacitor, the laminate is heat-treated at 120°C to 150°C, the laminate is cut to form a capacitor element, and a lead wire is welded to the capacitor element. As a result, we have completed a capacitor without exterior packaging. Further, surface mounting of such a surface mount type multilayer film capacitor is performed by flow or reflow soldering.

0004

SUMMARY OF THE INVENTION However, surface mount type multilayer film capacitors manufactured as unpackaged products by the conventional manufacturing method as described above have a drawback of poor heat resistance. That is, when a surface-mount type multilayer film capacitor manufactured as a package-less product by the above-described method is surface-mounted on a board, the film is easily deformed by the heat of soldering, regardless of flow or reflow. This deformation of the film causes the plastic film and the metal electrode to separate, impairing its function as a capacitor, resulting in a high incidence of defective products, which has become a problem.

The present invention was proposed in order to solve the problems of the prior art as described above, and its purpose is to prevent the film from deforming even during surface mounting, and to maintain its function as a capacitor. An object of the present invention is to provide an excellent method for manufacturing a surface-mount multilayer film capacitor, which can produce a surface-mount multilayer film capacitor having high heat resistance that can be reliably maintained.

[0006]

[Means for Solving the Problems] The method for manufacturing a surface-mounted laminated film capacitor of the present invention focuses on the processing temperature of a metallized plastic film, and the heat resistance temperature of a metallized plastic film is proportional to the processing temperature. This proposal was made after conducting an experiment on the relationship between the processing temperature and the heat-resistant temperature based on the assumption, and confirming the proportional relationship.

That is, in the method of manufacturing a surface-mount type multilayer film capacitor of the present invention, metallized plastic films are laminated and wound around a large-diameter winding core to form a laminate, and a thermally sprayed metal layer is applied to both end surfaces of the laminate. In a method for manufacturing a surface-mounted multilayer film capacitor by forming a laminate, heat treating the laminate at a predetermined temperature, and then cutting the laminate, the heat treatment of the laminate is performed on a film of metallized plastic film forming the laminate. It is characterized by being carried out at a temperature near the melting point of the main body.

Specifically, as the metallized plastic film, it is possible to use, for example, a metallized PPS (polyphenylene sulfide) film, and in this case, heat treatment is performed at a temperature of around 270°C.

[0009]

[Function] By the method of manufacturing a surface-mount type multilayer film capacitor of the present invention having the above-described structure, a surface-mount type multilayer film capacitor having high heat resistance can be obtained. That is, as mentioned above, as the metalized plastic film of the surface mount type laminated film capacitor, for example, metalized PPS (polyphenylene sulfide) is used.
Film, etc. can be used, but the melting point of this PPS film is about 270°C, which is higher than the conventional heat treatment temperature of 120°C.
The temperature is much higher than 150°C. By heat-treating the laminate of metallized plastic films at such high temperatures, the heat resistance of the metallized plastic films can be significantly improved.

[0010] As mentioned above, this effect is obvious from the proportional relationship between the processing temperature and the heat resistance temperature of the metallized plastic film, which was confirmed through experiments by the inventor. For example, FIG. 1 is a heat resistance characteristic diagram showing the results of investigating the relationship between the processing temperature and the heat resistance temperature of a PPS film. More specifically, this FIG. 1 shows that for a PPS film,
After processing for 2 hours at each temperature within the temperature range of 210°C to 270°C, it was immersed in a solder bath at each temperature within a wider (lower limit) temperature range for 10 seconds to determine whether the film was deformed or not. The results are shown with the temperature at which deformation occurs as the heat-resistant temperature. From this figure 1, P
It is clear that a proportional relationship exists between the processing temperature and the heat resistance temperature of the PS film. Similar results have also been confirmed for other plastic films.

Therefore, when a laminate of metallized plastic films is heat treated at a high temperature close to the melting point of the plastic film used, for example 270°C (in the case of PPS film), as in the method of the present invention, 12
Compared to a case where heat treatment is performed at an extremely low temperature of 0 to 150° C., a surface-mount type multilayer film capacitor can be obtained which has high heat resistance corresponding to this treatment temperature. In the thus obtained surface mount type multilayer film capacitor according to the present invention, the film does not deform even with the heat of soldering during surface mounting, and the function as a capacitor can be reliably maintained. can.

0012

[Example] An example of the method for manufacturing a surface mount type multilayer film capacitor according to the present invention will be described below with reference to FIGS. 2 to 6.
This will be explained in detail with reference to .

First, FIG. 2 shows a large-diameter drum 1, which is a large-diameter winding core, and a metallized PPS film laminated and wound to form a 2.5 m long drum.
A laminate 2 with a thickness of m is formed, and on both sides of this laminate 2,
FIG. 3 is a diagram showing a state in which an aluminum metallicon layer 3 is formed as a sprayed metal layer by thermal spraying of aluminum. FIG. 3 is an enlarged cross-sectional view of FIG. 2, and 4 in the figure is a protective film.

More specifically, a PPS film with a thickness of 50 μm is wound on the large-diameter drum 1 as the protective film 4, and the film is laminated and wound until the thickness becomes 0.5 mm. , a pair of metallized PPS films were laminated and wound to a thickness of 1.5 mm, and then a 50 μm thick PPS film was again wound on top of this, and laminated and wound to a thickness of 0.5 mm to form a laminate 2.
form. Thereafter, aluminum is thermally sprayed from both sides of the large-diameter drum 1 to form aluminum metallic layers 3 on both sides of the laminate 2.

Next, the laminate 2 is transferred from the large-diameter drum 1.
It is cut into a length of 20 cm to obtain a mother element 5 as shown in FIG. Then, the cut out mother element 5 was weighed 5 kg.
The film is heated for 2 hours at a high temperature of 270°C, which is close to the melting point of the PPS film, while applying a pressure of /cm2 to form a stick as shown in FIG.

Next, the side surface of the stick-shaped base element 5,
That is, copper is thermally sprayed on the surface of the aluminum metallicon layer 3,
A copper metallicon layer 6 is formed as a second sprayed metal layer. Thereafter, the surface of the copper metallicon layer 6 is polished, and the mother element 5 is cut into a length of 3 mm to obtain a capacitor element 7 as shown in FIG. The surface of the copper metallic layer 6 of the capacitor element 7 thus obtained is plated with solder to form a solder plating layer 8 as shown in FIG. Finally, a resin coating is applied to the cut surface of the capacitor element 7 using a resin having excellent heat and moisture resistance to form a resin coating layer 9, thereby completing a surface-mounted laminated film capacitor.

[0017] By manufacturing according to the above method,
The heat resistance of the capacitor can be significantly improved compared to conventional capacitors, and the film will not be deformed even by the heat of soldering. That is, as mentioned above, the heat resistance temperature of the PPS film is proportional to the processing temperature, and as in this example, it is
When processed at ℃, PPS film has a high heat resistance of approximately 260℃, as shown in Figure 1.
Can sufficiently withstand the heat of soldering during surface mounting. Therefore, in the surface mount type laminated film capacitor manufactured by the method of this example, the film will not be deformed even by the heat of soldering during surface mounting, and the function as a capacitor can be reliably maintained. .

Furthermore, in this embodiment, the resin coating layer 8 is formed on the cut surface of the capacitor element 7 using a resin having excellent heat resistance and moisture resistance, so that there is an advantage that the moisture resistance can be improved. .

Note that the present invention is not limited to the above embodiments, and for example, the plastic film used is not limited to PPS film, and other plastic films can be used as well. The heat treatment temperature can also be appropriately selected depending on the type of film. Furthermore, since the present invention is characterized by the treatment temperature during the manufacturing process, conditions other than the treatment temperature and each process other than the heat treatment step can be appropriately selected.

[0020]

As described above, in the manufacturing method of the present invention, the laminate is heat-treated at a temperature close to the melting point of the film body of the metallized plastic film forming the laminate, thereby making it possible to Also, it is possible to manufacture a surface-mount type multilayer film capacitor that does not deform the film and has high heat resistance to the extent that it can reliably maintain its function as a capacitor.

[Brief explanation of the drawing]

FIG. 1 is a heat resistance characteristic diagram showing the relationship between processing temperature and heat resistance temperature of a PPS film.

FIG. 2 is a plan view showing a state in which a laminate is formed around a large-diameter drum and aluminum metallicon layers are formed on both sides of the laminate in an embodiment of the method for manufacturing a surface-mounted laminated film capacitor according to the present invention. .

FIG. 3 is an enlarged cross-sectional view of FIG. 2;

FIG. 4 is a plan view showing a mother element obtained by cutting out the laminate from a large-diameter drum in the embodiment of FIG. 2;

FIG. 5 is a plan view showing a stick-shaped mother element obtained by heat-treating the mother element of FIG. 4 in the example of FIG. 2;

FIG. 6 is a perspective view showing a surface mount type multilayer film capacitor finally obtained in the example of FIG. 2;

[Explanation of symbols]

1 Large-diameter drum (large-diameter winding core) 2 Laminated body 3 Aluminum metallicon layer (sprayed metal layer) 4 Protective film 5 Mother element 6 Copper metallicon layer (second sprayed metal layer) 7 Capacitor element 8 Solder plating layer 9 Resin coating layer

Claims (2)

[Claims] Claim 1: A laminate is formed by laminating and winding metallized plastic films around a large-diameter winding core, a sprayed metal layer is formed on both end surfaces of the laminate, and the laminate is heat-treated at a predetermined temperature, and then The method for manufacturing a surface-mount type multilayer film capacitor by cutting this laminate is characterized in that the laminate is heat-treated at a temperature near the melting point of the film body of the metallized plastic film forming the laminate. A method for manufacturing a surface-mount laminated film capacitor. [Claim 2] As a metallized plastic film,
2. The method of manufacturing a surface-mount multilayer film capacitor according to claim 1, wherein a metallized PPS (polyphenylene sulfide) film is used and the laminate is heat-treated at a temperature around 270°C.