JPS59750Y2 - molded electrical parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molded electrical component, such as a molded plastic film capacitor, in which the periphery of an electrical component housed in a case is hardened with resin.

Conventionally, with this type of plastic film capacitor mainly used for AC power supplies, when the element is housed in the case,
After injecting enough epoxy resin to hold the element, the resin is further injected to the top of the case and cured by heating.

However, since the resin is injected and cured with the main focus on moisture resistance, there are few measures taken against damage to the device due to charging/discharging, lightning protection, etc.

That is, the gas generated when the element is destroyed only escapes from the upper surface of the case along the gap between the resin and the case, so the case and resin are likely to scatter due to gas pressure.
Therefore, the elements are exposed and there are safety problems.

For this reason, it is necessary to forcefully press down the resin with the case, but this has the disadvantage that the case becomes large and the cost inevitably increases.

The present invention has been devised to correct the above-mentioned defects, and in the molded electrical component mentioned at the beginning, the resin is (a) a resin layer (e.g., an epoxy resin layer that covers most of the electrical component); and (b) a second resin layer that is adjacent to the first resin layer and is present in other parts around the electrical component. a resin layer (e.g., an epoxy resin layer), and a sheet-like resin layer having a better degassing effect than these resin layers between the first resin layer and the second resin layer. A third layer (for example, a deposited layer of a silicone defoamer added in advance to the epoxy resin) is provided to extend from the periphery of the electrical component to the inner peripheral surface of the case. This relates to molded electrical parts.

By configuring in this way, it is possible to not only provide moisture resistance, but also to prevent the resin and case from scattering when the device is destroyed, and to prevent the device from being exposed, thereby providing a component with high safety and low cost.

Next, an embodiment in which the present invention is applied to a plastic film container will be described with reference to the drawings.

First, the configuration of the capacitor according to this embodiment will be explained.

This container 1 consists of a case 2, an element 4 housed within the case or having a lead 3 attached thereto, resin layers 5 and 6 adjacent to each other that harden this element from the periphery, and a layer existing at the boundary between these resin layers. It is constituted by an interface layer 7 that is

The interface layer 7 is formed by depositing a silicone defoaming agent, which will be described later, and is formed around the entire periphery of the element 4 in the area where the element 4 is most likely to receive impact when it is broken.

Therefore, both the side fat layers 5 and 6 are solidified while being separated from each other by the interface layer 7.

The element 4 is a conventionally known element consisting of a plastic film as a dielectric and a metal foil or metallized plastic film capacitor element as an electrode.

Next, a method of manufacturing this container 1 will be explained.

First, the element 4 is placed in the case 2, and an epoxy resin containing a silicone defoaming agent is injected to the level shown in FIGS. 2 and 3 (first injection).

This epoxy resin may consist of those shown in the table below.

In addition, the silicone-based defoamer used partially contains about 60% silicone, is chemically inert, and has an amount that can effectively remove air bubbles contained in the liquid, and a hardened product. The amount to be added is determined by keeping a balance with the amount that remains on the surface and does not lose its appearance.

Generally, the amount of silicone defoaming agent added is 0.5 to 3%.
The content is preferably about 0.5% for low viscosity resins and about 1% for high viscosity resins.

After this first injection, the epoxy resin is cured by heating at 85° C. for 4 hours.

This temperature also serves as a temperature for slow aging of the element 4.

By heating the epoxy resin during curing, the silicone defoamer in the resin floats to the surface and precipitates, forming the above-mentioned interface layer 7 on the cured surface.

Next, an epoxy resin made of the same components as the resin layer is injected onto the upper surface of the heat-cured resin layer 5 up to the upper surface of the case 2 (second injection), and heated and cured at 85° C. for 6 hours. Form layer 6.

However, at this time, since the interface layer 7 exists on the surface of the resin layer 5, the resin on the resin layer 6 side may invade the resin layer 5.
It will not melt.

Therefore, after heat curing, both side fat layers 5,
6 will be clearly separated.

The reason why the amount of silicone defoamer added was set to 0.5 to 3% when injecting the resin layer 5 is that if it is less than 0.5%, it is too small and the effect of forming an interface and the degassing effect described below are poor. On the other hand, if it exceeds 3%, it is too much and the amount of silicone precipitated is large, making it easy to become sticky.

Furthermore, if the resin layer 5 side contains a dinocone defoaming agent, this defoaming agent forms the interface layer 7 as described above, so the second injection is performed when the resin layer 5 is not completely cured. can be done.

In this sense, the resin layer 6 side does not need to contain a silicone defoamer, but it is better from a process standpoint if both side fat layers 5 and 6 contain a silicone defoamer. Good workability.

The characteristics of the capacitor 1 manufactured as described above will be explained next.

If the element 4 is destroyed due to charging/discharging, lightning protection, etc., the generated gas must be vented and the gas pressure must be released to prevent the case 2 and the element 4 from scattering and the element 4 from being exposed.

According to this embodiment, between the two phase resin layers 5 and 6 there is an interface layer 7 made of dinocone which is relatively elastic and has a better degassing effect than the resin layers 5 and 6. As shown in FIG.
and case 2 in the direction of arrow 9.

Therefore, unlike in the conventional case, the resin and the case do not break and scatter, making it possible to provide an extremely safe capacitor.

In some cases, the gas may not escape in the direction of arrow 9 and case 2 may be partially destroyed by the pressure in the direction of arrow 8, but the degree of destruction is small and the resin side is almost destroyed. There is no problem because there is nothing to do.

Since the interface layer 7 is unevenly distributed on the lead extraction side of the element 4, it can extremely effectively absorb the impact caused by the gas generated at the time of the above-mentioned breakdown.

It goes without saying that the presence of the resin layers 5 and 6 also ensures moisture resistance of the element.

In the conventional configuration, it is also possible to absorb the impact at the time of breakage by imparting appropriate hardness or softness to the mold resin, but it is difficult to blend the resin components to obtain such hardness.

On the other hand, in this embodiment, the above-mentioned simple structure makes it possible to easily absorb shock.

Moreover, since gas can be effectively vented, the case 2 can be made smaller, which is advantageous in terms of cost.

Although the present invention has been described above based on one embodiment, it will be understood that the present invention is not limited to this embodiment and can be modified in various ways.

For example, the molding resin and the material of the interface layer 7 may be changed.

In particular, the interface layer 7 only needs to have the effect of preventing the adhesion of both side fat layers 5 and 6 and have a better degassing effect than both side fat layers 5 and 6, and may not be composed of other mold release agents. Alternatively, after forming the resin layer 5, a layer corresponding to the interface layer 7 may be separately disposed on the upper surface (eg, poured), and then the second injection may be performed.

Further, the formation position of the interface layer 7 may also be changed depending on the type of component.

Note that the present invention is of course applicable not only to film containers but also to other molded parts.

As described above, in the present invention, the resin for hardening the electrical component is composed of a first resin layer and a second resin layer, and these resins are provided between the first resin layer and the second resin layer. Since the sheet-like third layer, which has a better degassing effect than the third layer, extends from the periphery of the electrical component to the inner circumferential surface of the case, it goes without saying that moisture resistance is guaranteed. , the gas generated at the time of element destruction is transferred to the first resin layer and the second resin layer.
The molded electrical component is guided to the inner circumferential surface of the case through the sheet-shaped third layer extending over a relatively wide area between the resin layer and the case, and further passed between the resin layer and the case. It is possible to effectively release the resin to the outside, prevent the resin and the case from scattering and expose the elements, and therefore provide a molded electrical component with extremely high safety.

In addition, since scattering of the resin and the case can be prevented by an extremely simple structure, especially by the presence of a sheet-like third layer provided between the first resin layer and the second resin layer, mold electric It is possible to miniaturize the parts, and it is also easy to manufacture molded electrical parts, making it possible to reduce costs.

In addition, since scattering of the resin and the case can be prevented by a very simple structure, especially by the presence of the third layer, the overall size can be reduced, and cost I and cost can be reduced.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a plastic film capacitor, in which Fig. 1 is a partially cutaway perspective view of the capacitor, Fig. 2 is a vertical sectional view of Fig. 1, and Fig. 3 is a cross-sectional view of the capacitor. FIG. 2 is a sectional view taken along the line ■■■-III in FIG. 2, and FIG. 4 is a partially enlarged view of FIG. 3 for explaining degassing. In the symbols used in the drawings, 2 is a case, 4 is an element, 5 and 6 are resin layers, and 7 is an interface layer.

Claims (1)

[Claims for Utility Model Registration] In a molded electrical component in which the periphery of an electrical component housed in a case is hardened with a resin, the resin is (a) (b) a second resin layer existing in other parts around the electric component in a state adjacent to the first resin layer; A sheet-like third layer having a better degassing effect than these resin layers is extended between the resin layer and the second resin layer from around the electrical component to the inner circumferential surface of the case. Mold electric part Roro 0 characterized by being provided so that