JPH02152206A - Insulating coating of electric element - Google Patents

Abstract

PURPOSE:To easily maintain a temperature and to make an adhesion irregularity and a coating irregularity of an insulating material hard to cause by a method wherein the insulating material which has adhered to the surface of an electric element or with which the surface of the electric element has been coated is melted and coated by self-heating by applying an electric current to the electric element. CONSTITUTION:An electric current is applied to electrodes 2, 3; an electric element 1 itself is preheated by self-heating. A heat-generating temperature during this preheating is controlled by adjusting an amount of the electric current (an applied voltage) or the like. While the electric current is being applied, a powdery insulating material 4 is applied to the surface of the electric element 1. Since this material is applied continuously from a preheating state, a temperature on the side of the element 1 does not fluctuate and the material can be applied uniformly. The resin material 4 is hardened by successive self- heating of the electric element 1; it is possible to obtain a uniform and filmlike insulating coating 5.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is directed to an electric element (
The present invention relates to an insulating coating method for an electrical element, which uses the self-heating of an electrical component to coat an insulating material.

<Prior Art> Conventionally, resins, ceramics, and the like are generally used as insulating materials for electric elements.

Then, when covering with a specific insulating material, the above-mentioned resins, ceramics, etc. are attached or coated on the surface of the electric element,
Thereafter, it is heated from the outside to cure and coat.

As this external heating means, an oven, a heating device with a built-in infrared heater, etc. are used.

For example, taking a thermosetting resin as an example, the resin is applied to the surface of an electric element, and then heated and cured.

Furthermore, in the case of a powdered material such as an epoxy resin, the electric element is heated (preheated) in advance, the resin powder is attached to the surface, and the resin powder is heated and cured in this state.

<Problem to be solved by the invention> However, in the case of the above insulation coating method, (1
) that external heating means are required separate from the electrical elements;
(2) In the case of a preheating method using external heating, it is difficult to maintain the temperature during process movement, and uneven adhesion or coating tends to occur in the insulating material adhered or applied to the surface of the electric element. Depending on the shape, for example, if there are edges or thin parts, these parts tend to cool down after preheating and before adhesion or application, so the thickness of the coating tends to be uneven; (4) Furthermore, In order to obtain a thick film coating, it is necessary to repeat the steps of preheating, adhesion or application of the insulating material, and curing several times, and in this case, the insulating layer takes on a multilayered structure, which weakens its strength. There were drawbacks such as.

The present invention has been made in view of the conventional circumstances.

A feature of the present invention is that in an electric element that self-heats when energized, an insulating material attached or coated on the surface of the electric element is applied to the electric element. A method for insulating an electrical element in which the electrical element is melted and coated by self-heating due to energization.

Effects> With the above configuration, if the electric element itself is energized to generate self-heating, an external heating means or the like is not required, and as will be described later, a uniform insulating coating whose thickness etc. can be freely controlled can be obtained.

<Example> Figures 1 (8) to (C) show an example of the method for insulating coating of an electric element according to the present invention.

In the figure, 1 contains a resistor, coil, transistor,
It is an electric element with built-in electronic (electrical) parts such as FETs, light emitters, capacitors, and varistors, and generates heat by itself when energized. Electrodes 2 and 3 for energization are drawn out from the main body as lead wires or terminals. ing. Note that depending on the element 1, the number of electrodes 2.3 is not limited to two.

The surface (outer surface) of the electric element 1 is coated with an insulating coating, and in this example, it is made of epoxy resin, diallyl phthalate resin, silicone resin, phenol resin, polyimide resin, melamine resin, urea resin, etc. This is a case where an insulating material made of a powdered thermosetting resin is used, and is carried out as follows.

First, in the state shown in FIG. 1(^), electricity is applied to the electrodes 2 and 3 to cause the electric element 1 itself to self-heat and preheat. The temperature of the heat generated during preheating may be controlled by adjusting the energization M (applied voltage) or the like.

Next, as shown in FIG. 1(B), a powdered insulating material 4 is adhered to the surface of the electric element 1 while the energization is continued.

Since this adhesion is performed continuously from the preheated state, there is no temperature fluctuation on the element 1 side, and it can be performed uniformly. This uniform adhesion is achieved by an internal heating method based on self-heating of the element 1 itself, and is therefore not greatly influenced by the shape of the element. In addition, the amount of adhesion can also be freely controlled by adjusting the adhesion time.

The powdered insulating material 4 deposited in a desired amount in this way is then heated by the subsequent self-heating of the electric element 1, so that the resin material 4 hardens as shown in FIG. 1(C). Thus, a uniform film-like insulation coating 5 is obtained. The heat generation temperature during curing may also be controlled by adjusting the amount of current (applied voltage), etc., to appropriately correspond to the curing temperature of the insulating material 4 used.

FIGS. 2(8) to 2(C) show other embodiments of the method for insulating an electric element according to the present invention.

In this case, the insulating material 4a is a thermosetting resin such as polyester or polyurethane that is liquid at room temperature, or a thermosetting resin that is in the form of a paint by adding a solvent. The case is basically the same as the case in Fig. 1 (A) to (C) above, but the case in Fig. 2 (
After preheating the electric element 1 shown in A), the preheated electric element 1 is immersed in a liquid insulating material 4a placed in a suitable container 6, as shown in FIG. As a result, the liquid insulating material 4a is applied and then cured by the self-heating of the electric element 1 as shown in FIG. It's something you get.

FIGS. 3A to 3D show still another embodiment of the method for insulating an electric element according to the present invention.

In this case, the insulating material is an insulating material made of powdered thermoplastic resin such as polyethylene, polyvinyl chloride, polystyrene, polypropylene, polyethylene terephthalate, polycarbonate, polybutadiene, polyacetal, polyamide, fluororesin, vinyl acetate, etc. This is the case when material 4b is used.

In this case as well, the process is basically the same as in the cases shown in Figures 1 (A) to (C) above, but due to the nature of the thermoplastic resin, Figure 3 (A)
), the adhesion process shown in Figure 31 (B), and the adhesion process shown in Figure 3 (C).
After the heating step shown in ), the cooling step shown in FIG. 3(D) is added.

After curing by cooling, a uniform film-like insulating coating 5 can be obtained.

In addition, although each of the above-mentioned examples deals with the cases of powdered and liquid thermosetting resins and powdered thermoplastic resins, the present invention is of course not limited to these. In addition to resins, it can also be applied to low-melting ceramics, glass, and other coating materials. Further, in the present invention, although it is preferable to include a preheating step, it may be omitted depending on the material used.

<Effects of the Invention> As is clear from the above description, the method for insulating an electric element of the present invention provides the following effects.

(1) Since the self-heating of the electric element itself is utilized, no external heating means is required.

(2) Only one energization is required, so if you have a power source, it can be carried out easily and easily.

(3) Since it is an internal heating method using self-heating, temperature can be easily maintained, uneven adhesion or coating of the insulating material is less likely to occur, and a uniform, high-quality insulating coating can be obtained.

(4) The uniformity of this coating does not depend much on the shape of the element because of the ease of temperature maintenance. In other words, uniform coverage can be obtained not only on protruding parts but also on narrow parts, regardless of the shape.

(5) Even when obtaining a thick film coating, it can be easily handled by controlling the adhesion, coating time, amount, etc., and there is no need to repeat the same coating operation as in the past.

(6) Since a thick film coating can be formed at once in this way, an integrated high-strength insulation coating can be obtained.

[Brief explanation of the drawing]

FIGS. 1(Δ) to (B) are schematic process diagrams showing each step of an embodiment of the insulating coating method for an electric/electronic device according to the present invention, and FIGS. 2(A) to (B) are according to the present invention. FIG. 3 (A
) to (C) are schematic process diagrams showing each step of yet another embodiment of the method for insulating coating an electric element according to the present invention. In the figure, l... Electric element, 2.3... Electrode, 4.4a, 4b... Insulating material, 5... Insulating coating, Fig. 1fA) (B ) (CI Figure 2 (A) (B) (c) Procedural amendment (at 0) 1. Indication of the case 1988 Patent Application No. 306736 2 Title of invention Insulating coating method for electric elements 3 Make amendments Relationship with the case Patent applicant address: 5-1 Kiba-chome, Koto-ku, Tokyo Name: Fujikura
Electric Wire Co., Ltd. Representative Makoto Kagaya 4, Agent ■141 '1! X03 (440)-67
61 Address: 5-23-1-6 Higashigotanda, Tokyo Parts Ward,
Target of amendment: "A in the description, column 1 of Figure 1 (C), Figure 2 (C), and Figure 3 (D) in the brief description of the drawings, line 1 in the text 1■")~(C)'' 2. Akira, f111, line 3, line 8)~(C)'' 3, Mei II, line 5, line 5', A)~(D)'' 9 Page (the column for a brief explanation of the drawings), "Fig. 1 (^) to (B)" should be corrected as [Fig. 2 (8) to (B)" should be amended to "Fig. Figure 3 (and corrected.

Claims (1)

[Claims] In electric elements that self-heat when energized,
1. A method of insulating coating an electric element, comprising melting and coating an insulating material adhered or coated on the surface of the electric element by self-heating caused by energization of the electric element.