JPH0142616B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a chip-shaped film capacitor that has soldering heat resistance and excellent electrical characteristics. Conventional configurations and their problems With the miniaturization of electrical and electronic equipment, high-density mounting of electronic components is being promoted, and chip mounting is one of the effective means for this. Until now, the only capacitors that could be made into chips were ceramic capacitors, but recently tantalum electrolytic capacitors and aluminum electrolytic capacitors have also been made into chips. Of these, film capacitors were the only ones that were slow to adapt to chips. The biggest reason for this is the poor heat resistance of the plastic film itself, which is the dielectric material of the plastic film capacitor.
When immersed in a solder bath, fatal defects such as deformation of the device, missing capacitance, and short circuits between lead wires occurred. On the other hand, the heat-resistant films currently on the market are too thick and lack capacity, have too large electrical properties, especially the dielectric loss tangent, and are too expensive. It's inappropriate. Purpose of the Invention The present invention eliminates the drawbacks of the heat-resistant film itself by using the heat-resistant film only as a base material, not as a dielectric, and makes full use of its excellent thermal stability. The object of the present invention is to provide a chip-shaped film capacitor having better electrical characteristics. Structure of the Invention In order to achieve the above-mentioned object, the chip-shaped film capacitor of the present invention is provided by forming a vapor-deposited metal electrode on both sides of a heat-resistant plastic film, leaving one end in the same direction on the other surface; A thermosetting resin layer is formed on one side and a heat-resistant thermoplastic resin layer is formed on the other side so that only the vapor-deposited metal electrode portion close to the edge is exposed. The plastic films having the same structure are stacked so that the exposed electrode portions of each layer are in opposite directions and the thermosetting resin layer and the heat-resistant thermoplastic resin layer are overlapped, and the exposed electrodes are stacked on both sides of the laminate. A molten metal layer is provided on a vapor-deposited metal electrode. DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, the basics of the present invention will be explained before explaining the embodiments with reference to the drawings. A heat-resistant film with metal electrodes deposited on both sides is coated with a heat-resistant thermoplastic resin and a thermosetting resin on each side from above the metal electrodes, and the films are cut to size and then laminated in multiple layers. The electrode is drawn out from the vapor-deposited electrode by metal spraying on both sides. Here, the heat-resistant film refers to a film that does not melt or undergo extreme deformation at 260°C, and specifically refers to plastic films such as polyimide, polyamide, and polyamide-imide. In addition, heat-resistant thermoplastic resin has a heat distortion temperature of
Plastics with a dielectric loss tangent of 0.01 or less at 170°C or higher and 1KHz, specifically polysulfone, polyethersulfone, polyphenylene oxide, fluororesin, etc. On the other hand, thermosetting resin has a thermal decomposition temperature of 300℃ or higher and a dielectric loss tangent at 1KHz.
0.02 or less, and refers to epoxy resins, unsaturated polyester resins, polybutadiene, silicone resins, diallyl phthalate resins, triazine resins, etc. The role of the heat-resistant thermoplastic resin is to improve the performance of the capacitor by taking advantage of its excellent dielectric properties, and also to bond between each layer. On the other hand, the thermosetting resin layer serves to prevent a decrease in withstand voltage and insulation resistance due to creep or flow of the thermoplastic resin at high temperatures such as during solder dipping. Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG.
Cut it out so that the width A is 4 mm and the length B is 3 mm, and on both sides, cut out 0.5 mm from one end of the same side in the width direction.
Aluminum is vapor-deposited over the entire surface, leaving a thickness of 1 mm, to form electrodes 2 and 3. Next, as shown in Figure 2,
A thermoplastic resin lacquer is applied to the side where the electrode 2 is present, and then heated and dried to expose a portion of the electrode 2 adjacent to the widthwise end of the heat-resistant film 1, leaving a 0.5 mm gap. A thermoplastic resin layer 4 is formed with a width of mm, and a thermosetting resin layer 5 is formed on the electrode 3 side by the same coating method and completely cured. As shown in FIG. 2, a heat-resistant film 1' having electrodes 2', 3', a thermoplastic resin layer 4', and a thermosetting resin layer 5' formed thereon and the heat-resistant film 1 are placed on one side as shown in FIG. The thermosetting resin layer 5 and the other thermoplastic resin layer 4' are bonded together so that they are in contact with each other. At this time, the electrodes are exposed in opposite directions for each layer. Also, at this time, the overlapping portion of the opposing vapor deposition electrodes 3 and 2' has a length of 3 mm and a width of 3 mm. After that, the films are laminated one after another in the same way,
After laminating 100 layers of film, the film is heated at 200 to 240°C for 10 minutes while being lightly pressed from above and below in the lamination direction. As a result, each layer is completely bonded to each other. Aluminum is thermally sprayed to a thickness of 0.3 to 0.5 mm on both sides of the laminated film in the width direction, and as shown in Figure 3, the vapor deposition electrodes 2 and 3 to electrode 6 are oriented in one direction, and the evaporation electrode 2' is oriented in the opposite direction. , 3', respectively. Next, as shown in FIG. 4, nickel com leads 8 and 9 are welded to the electrodes 6 and 7, respectively, and the entire device is covered with a commercially available molded resin 10.
The chip-shaped film capacitor of the present invention is completed by bending the comb leads 8 and 9 protruding from the capacitor as shown in FIG. Table 1 shows specific combinations of the heat-resistant film, thermoplastic resin, and thermosetting resin used in the above examples. Further, Table 2 shows the initial characteristics of each combination example and the characteristics after being immersed in a 260° C. solder bath for 10 seconds. still

【table】

[Table] For comparison, the performance of commercially available polyester film capacitors is also listed in Table 2. Effects of the Invention As described above, according to the present invention, the following effects can be obtained. That is, as can be seen from Tables 1 and 2, the chip-shaped film capacitor of the present invention has a very low dielectric loss tangent compared to commercially available film capacitors, and moreover, it can be immersed in a solder bath at 260°C for 10 seconds. While commercially available products later suffered from a significant decrease in capacity and deterioration in insulation resistance, the product of the present invention exhibits almost no deterioration in characteristics, making it extremely useful as a new chip-shaped film capacitor with excellent electrical properties. be.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of a heat-resistant film with electrodes deposited on both sides, and FIG.
The figure is a cross-sectional view showing the state of two-layer lamination, Figure 3 is a cross-sectional view showing the metal sprayed state, Figure 4 is a perspective view showing the welded state of ComLead, and Figure 5 is the completed state with exterior packaging. FIG. 1, 1'...Heat-resistant film, 2, 2', 3,
3'... Vapor deposition electrode, 4,4'... Thermoplastic resin layer,
5, 5'... thermosetting resin layer, 6, 7... electrode,
8, 9... Comlead, 10... Molding resin.

Claims (1)

[Scope of Claims] 1. Vapor-deposited metal electrodes are formed on both sides of a heat-resistant plastic film, leaving one end in the same direction on the other entire surface, and only the vapor-deposited metal electrodes near the edges of the film are exposed from above. A thermosetting resin layer is formed on one side and a heat-resistant thermoplastic resin layer is formed on the other side, and the plastic film having the vapor-deposited metal electrode and the resin layer is layered layer by layer on the exposed electrode. The thermosetting resin layer and the heat-resistant thermoplastic resin layer were stacked so that their parts were in opposite directions and overlapped, and a molten metal layer was provided on the vapor-deposited gold layer electrodes exposed on both sides of this laminate. Chip-shaped film capacitor. 2. The chip-shaped film capacitor according to claim 1, wherein the heat-resistant plastic film is a film that does not melt or undergo extreme deformation at 260°C. 3 The resin of the heat-resistant thermoplastic resin layer has a heat distortion temperature of
The dielectric loss tangent measured at 170℃ or higher and at 1KHz is
The chip-shaped film capacitor according to claim 1, which is a heat-resistant thermoplastic resin of 0.01 or less. 4 The resin of the thermosetting resin layer has a thermal decomposition temperature of 300℃
The chip-shaped film capacitor according to claim 1, which is a thermosetting resin having the above properties and a dielectric loss tangent of 0.02 or less at 1 KHz.