JPH01287913A - Manufacture of chip type film capacitor - Google Patents

Abstract

PURPOSE:To contrive miniaturization and reduction both in the amount of equipment investment and cost of production of the title capacitor by a method wherein an electrode foil gluing and adhesion sheet sheathing system is adopted. CONSTITUTION:The title capacitor is composed of a circular drum 1, spacers 2a-2d, an aramid resin film 3, a copper foil 4, a copper-foil glued and adhered sheet 5, an electrode layer 6, three-layer wound material 7, the first layer wound material 7a, the second wound material 7b, the third layer wound material 7c, an electrode lead-out metallized contact part 8 and the like. Then, the adhesive sheet 5, on which a band-like electrode foil 4 is glued up to both end faces of the heat-resisting adhesive film 3 before or after insertion of the spacers 2a-2d, is wound around once or a plurality of turns in such a manner that the electrode foils 4 come in contact with the spacers 2a-2d, and an electrode is provided in advance. As a result, the miniaturization, the reduction both in the amount of equipment investment and the cost of production of the title capacitor can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a chip-type film capacitor.

2. Description of the Related Art In recent years, efforts have been made to make electronic devices more multifunctional and smaller, and the electronic components used in these devices have become lighter, thinner, shorter, and smaller. A typical example of this is the conversion of electronic components into chips.

Among chip-type capacitors, chip-type film capacitors currently have a larger volume and projected area than chip-type tantalum electrolytic capacitors and chip-type ceramic capacitors. In other words, a chip-type film capacitor is made by placing a pair of metallized plastic films with a thickness of 1 to 3 μm around a circular drum with a diameter of 600 inφ several 100 times, passing them through a spacer, and placing them on top of the film several 100 times, and repeating this process to form multiple layers. After forming and applying metallic contact to both end faces, heat treatment and pre-cutting into semicircular shapes, then cutting to specified dimensions, welding a lead frame to the metallic contact part to make it compatible with surface mount method, and improving shape and dimensional accuracy. In order to increase this, chip-type film capacitors are manufactured using molding such as transfer molding (injection molding) as an exterior packaging method.

Problems to be Solved by the Invention However, molding such as transfer molding requires an exterior thickness of 0.5 mm or more, and even if the dielectric film is made thicker, the exterior thickness ratio becomes thicker (which is different from other chip-type capacitors). In addition, the investment cost for equipment such as welding machines and molding machines for welding external extraction electrodes such as lead frames is high, and the thinner the exterior thickness is, the more the internal elements will be damaged by the pressure during molding. There were drawbacks such as a significant decrease in yield due to spillage and increased costs.

Means for Solving the Problems The present invention aims to provide a method for manufacturing a chip-type film capacitor that eliminates the above-mentioned drawbacks, and is manufactured by the following process sequence.

(b) A step of winding a pair of metallized plastic films around a drum a predetermined number of times to form a multi-layered wound product through a spacer, and a heat-resistant adhesive film before or after inserting the spacer in the winding step. (b) forming an electrode part in advance by winding an adhesive sheet with a band-shaped electrode foil pasted on both end faces of the multi-layered material once or multiple times so that the electrode foil is in contact with a spacer; A metallicon process of spraying a metal material on both end faces to form an electrode lead-out metallicon part; (c) a heat treatment process at a predetermined temperature; (d) a step of preliminary cutting into a plurality of pieces; and (v) the electrode lead-out metallicon part. (f) polishing the end face of the electrode lead metal contact part; (g) plating the external electrode lead metal contact part and the electrode foil part. (h) cutting process to form a capacitor with a predetermined capacitance; The capacitor element has a viscosity of 200~200 to improve moisture resistance. 400c
impregnation treatment with a low viscosity liquid thermosetting resin having a low surface tension of 20 to 30 dynes. Further, only a liquid resin curing furnace and a cutting machine are required as equipment, and the process can be greatly simplified.

EXAMPLE Hereinafter, one example of the method for manufacturing a chip-type film capacitor of the present invention will be described.

As shown in FIG. 2, a spacer 2a is formed by winding a 25 μm thick polyethylene terephthalate film a predetermined number of times around a circular drum 1 with a diameter of 600 mmφ as the core, and a spacer 2a is formed around the outer periphery of this spacer 2a as shown in FIG. A strip-shaped copper foil 4 with a thickness of 18 μm and a width of 1111 is pasted on both end faces of an aracid resin film 3 with a thickness of 16 μm.For copper foil pasting, an adhesive sheet 5 is placed inside the copper foil portion 4 (in contact with the spacer 2a).
The electrode layer 6 is formed by winding it once, and on the outer periphery of this electrode layer 6, aluminum is deposited as an electrode with a thickness of 1.5 to 3 μm.
A pair of metallized polyethylene terephthalate films (hereinafter referred to as MPET films) or metallized polyphenylene fulfilte films (hereinafter referred to as MPPS films) of 500 m are superposed and wound 500 times, and the copper foil is pasted on the outer periphery of the adhesive sheet 5. The electrode layer 6 is formed by winding once with the foil part 4 on the outside to form a 1Nth winding 7a, and the spacer 2b is formed on the outer periphery of the first layer winding 7a in the same manner as described above. Copper foil is attached to the outer periphery of this spacer 2b in the same manner as described above by winding the adhesive sheet 5 once with the copper foil portion 4 inside to form an electrode layer 6. A pair of MPET films or MPPS films are superimposed and wound, for example, 494 times to obtain the same capacitance as the first layer wound material 7a, and the W4 foil is pasted on the outer periphery with the adhesive sheet 5 on the outside. The electrode layer 6 is wound once to form the second layer winding 7b, and the spacer 2C is formed on the outer periphery of the second layer winding 7b in the same manner as above, and the outer periphery of the spacer 2C is In the same way as above, W4 foil is pasted by wrapping it once with the adhesive sheet 5 inside to form the electrode 16.
A pair of MPETPE films or MPPS films are superimposed on the outer periphery of this electrode layer 6 in the same manner as described above. It is wound, for example, 488 times so as to obtain the same capacitance as the one-piece winding 7a, and the above-mentioned! 1iiiI foil pasting is performed by wrapping the adhesive sheet 5 once on the outside to form the electrode layer 6, and then
A layered winding 7C is formed, and spacers 1-2d similar to those described above are formed on the outer periphery of the third layer winding 7c.
form. Then, zinc or zinc and solder is thermally sprayed onto both end faces of this three-layered winding 7 to form an electrode lead-out metallic contact portion 8 having a thickness of 0.3 to 0.51 mm. After that, about 180℃ (
Heat treatment is performed at a temperature of 170 to 230° C. (preferably in the range of 170 to 230°C) for about 2 hours (1 to 3 hours is also acceptable), and after the heat treatment is completed, the 3Jii wound material 7 is removed from the circular drum 1 as shown in FIG. First, it is cut into two semicircular parts, and then the semicircular 3) m windings 7 which have been cut into two parts are separated one layer at a time into each m semicircular windings 7a, 7b, and 7C ( (Fig. 5 shows a cross-sectional view), the separated layers 7a, 7b, 7C have a viscosity of 200 to 400 cps to improve moisture resistance.
, low surface tension 20-30 dynes, glass transition temperature 100-
A low viscosity liquid epoxy resin at 150°C is heated to a vacuum degree of 10 to 3 (
impregnation for 3 minutes, followed by heating at 135° C. for 2 hours to cure.

Since the end face of the electrode drawer metallicon portion 8 is a rough surface and has fine pores, the epoxy resin cured by the impregnation and heat curing treatment is attached, so that the electrode drawer can be drawn out as shown in FIG. 6 (cross-sectional view). The end face of the metallcon part 8 is polished to smooth it and remove the resin attached to the end face, and then the W4 foil part 4 and the electrode lead-out metallicon part 8 are solder plated 9.

After solder plating, the chip-type film capacitor 10 with a predetermined capacitance as shown in FIG.
Manufacture many pieces.

In the embodiments described above, the MPETPE or MP
Although PS film was used, other metallized plastic films may be used, and although a three-layer winding is shown, a winding of four or more layers may be used.

In the above-mentioned embodiments, an arachid resin film was used as the adhesive sheet for attaching the copper foil, but films such as polyimide film, polyphenylene fluoride film, polyethylene terephthalate film, and U polymer film may also be used. The copper foil pasted on the adhesive sheet may be rolled copper foil, untreated W4 foil, or electrolytic copper foil. In addition to copper foil, metal foil such as nickel foil, aluminum foil, or tin foil may also be used as electrode foil. .

In the above embodiments, epoxy resin was used, but thermosetting resins such as polyester resin and urethane resin may also be used.

In the embodiments described above, a circular drum was used, but the shape of the drum is not limited to circular.

Effects of the Invention As mentioned above, the method for manufacturing a chip-type film capacitor of the present invention is as follows: (A) Adhesive sheet exterior method is adopted for electrode foil attachment, and an adhesive sheet with an exterior thickness of 0.1 μ or less is used, so it is easier to manufacture than the conventional method. It can be made smaller than chip-type film capacitors made by this type of molding.

(B) Since a lead frame is not used, a molding machine and a welding machine are not required, and the amount of capital investment can be significantly reduced.

(C) The area of the external lead electrode part is large, and the thickness of the external lead electrode part is 0.1 greater than the thickness of the capacitor element.
Since the layer is thicker, it is easier to attach it to the machine and improves solderability.

(D) Dimensional accuracy can be made comparable to conventional molding methods.

(E) Since a low viscosity liquid thermally effective resin is used, the intrusion of moisture is prevented and the moisture resistance of the capacitor is improved.

(F) The capacitor production cost is low and economical.

It has the following effects and has great industrial and practical value.

[Brief explanation of the drawing]

Figures 1 to 6 show the manufacturing process of the chip-type film capacitor of the present invention, Figure 1 is a perspective view of the finished product, and Figure 2 is a cross-section of the main part of the three-layered product wound around a circular drum. Figure 3 is a perspective view of the adhesive sheet for pasting the copper foil, and Figure 4 is a semicircular 2
A front view of the divided three-layer winding, Fig. 5 is a cross-sectional view of the winding per layer with electrode lead metallized on both end faces, and Fig. 6 is a solder plated electrode lead metallized part and copper foil part. FIG. 1: Circular drums 2a, 2b, 2c, 2d Varnish spacer 3: Arashido resin film 4: Copper foil 5: Copper foil is attached with adhesive sheet 6: Electrical bridge layer 7: 3-layer winding 7a: 1st-layer winding 7b = 2nd layer winding 7C: 3rd N winding snout 8: Electrode lead metal contact portion 9: Solder plating 10: Chip type film capacitor Figure 1 Figure 2 Figure 5 Figure 6

Claims (1)

[Claims] A step of winding a pair of metallized plastic films around a drum a predetermined number of times to form a multi-layered wound product with a spacer interposed therebetween; a step of forming an electrode portion in advance by winding an adhesive sheet to which a band-shaped electrode foil is attached one or more times so that the electrode foil is in contact with a spacer; and forming electrode lead-out metallic contact portions on both end faces of the multilayer wound product. a step of heat-treating the multilayer winding at a predetermined temperature; a step of preliminarily cutting the multilayer winding into a plurality of pieces after the heat treatment; A step of impregnating and thermosetting with a curable resin, a step of polishing the end face of the electrode lead-out metal contact portion, a step of plating the external electrode lead-out metal contact portion and the electrode foil portion, and forming a capacitor with a required capacitance. A method for manufacturing a chip-type film capacitor, comprising a cutting process.