JPH05217801A - Dry capacitor with built-in discharge resistance - Google Patents

Abstract

PURPOSE:To prevent a crack from being caused on the surface of a discharge resistance by a method wherein the discharge resistance is housed in an insulating container, a space part is formed between the discharge resistance and a resin mold or the surface of the discharge resistance is coated with a fluorine- based mold-releasing agent and a gap part is formed between the discharge resistance and the resin mold. CONSTITUTION:In a dry capacitor 1 with a built-in resistance, one or a plurality of capacitor elements 2 and a discharge resistance 3 which has been housed in an insulating container 7 are connected in parallel by using lead wires 4; a terminal 6 for external extraction use is connected to the tip of the lead wire 4; this assembly is housed in an injection mold and dried in a vacuum; after that, a thermoset resin such as an epoxy resin, a polyester resin or the like is injected into the injection mold; the resin is heated and hardened; a resin mold 5 is formed; a space part 8 is formed between the discharge resistance 3 and the resin mold 5. Thereby, it is possible to avoid a physical stress due to the thermal hardening contraction, the cold and heat cycle deformation or the like of the molding resin, and the quality of the discharge resistance is stabilized for a long time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry capacitor with a built-in discharge resistor in which a space or a gap is formed between a discharge resistor and a resin mold to stabilize quality and improve reliability. is there.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional dry capacitor with a built-in discharge resistor, (A) is an internal circuit configuration diagram, (B) is an enlarged explanatory view of a discharge resistor, and a dry capacitor with a built-in discharge resistor is 1
One or more capacitor elements 22 and discharge resistors 23
The mainstream structure has a structure in which (for example, a carbon film fixed resistor) is connected in parallel with silicon-coated lead wires 24, a thermosetting resin such as an epoxy resin or a polyester resin is cast, and a resin mold 25 is formed. Reference numeral 26 is an external lead-out terminal connected to the lead wire 24.

[0003]

However, the dry capacitor with a built-in discharge resistor having the above-mentioned structure is cured and contracted when the thermosetting resin is thermally cured, and the thermal expansion and contraction of the thermosetting resin and the discharge resistor. There is a drawback that the withstand voltage performance of the discharge resistor is deteriorated and the resistance value is changed due to the generation of cracks on the surface of the discharge resistor due to the stress caused by the difference in the rate.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to provide a dry capacitor with a built-in discharge resistor that solves the above problems. That is, in a dry capacitor with a built-in discharge resistor, which is formed by connecting one or a plurality of capacitor elements and a discharge resistor in parallel and molding the resin, the discharge resistor is housed in an insulating container, and the discharge resistor and the resin mold are combined. A discharge resistor built-in, characterized in that a space is formed between the discharge resistors or a mold release agent is applied to the entire surface of the discharge resistors and then the resin molding is performed to form a gap between the discharge resistors and the resin mold. It is a dry condenser.

[0005]

With the structure having the space or gap formed as described above, it is possible to prevent the discharge resistor and the resin mold from directly contacting each other, and to prevent physical contact such as heat curing shrinkage of the molding resin and deformation of the heat cycle. You can avoid stress.

[0006]

EXAMPLE FIG. 1 shows a dry capacitor with a built-in discharge resistor according to the present invention.
2 will be described. FIG. 1 is an example,
(A) is an internal circuit configuration diagram, (B) is an enlarged view of essential parts, 1 is a dry capacitor with a built-in discharge resistor, 2 is one or more capacitor elements, 3 is a discharge resistor such as a carbon film fixed resistor 4 is a lead wire coated with a release agent such as silicon,
5 is a resin mold in which thermosetting resin such as epoxy resin or polyester resin is cast, 6 is a terminal for external drawing, 7
Is an insulating container made of synthetic resin or glass, and 8 is a space formed between the insulating container 7 and the discharge resistor 3.

The dry capacitor 1 with a built-in discharge resistor is
A single or a plurality of capacitor elements 2 and a discharge resistor 3 housed in an insulating container 7 are connected in parallel by a lead wire 4, and an external lead-out terminal 6 is connected to the tip of the lead wire 4 for casting ( (Not shown) and vacuum-dried, and then thermosetting resin such as epoxy resin or polyester resin is injected into the casting mold and cured by heating to form a resin mold 5, which is then taken out from the casting mold. The production is completed.

The manufactured dry capacitor with built-in discharge resistor 1
Since the discharge resistor 3 is housed in the insulating container 7 as described above, the space 8 is formed between the discharge resistor 3 and the insulating container 7, that is, between the discharge resistor 3 and the resin mold 5.
Is formed.

FIG. 2 shows another embodiment, (A) is an internal circuit configuration diagram, (B) is an enlarged view of essential parts, 11 is a dry capacitor with a built-in discharge resistor, 12 is one or a plurality of capacitor elements, 13 is a discharge resistor such as a carbon film fixed resistor, 14
Is a lead wire coated with a release agent such as silicon, 15 is a resin mold in which a thermosetting resin such as epoxy resin or polyester resin is cast, 16 is an external lead terminal, 17 is a fluorine-based release agent, and 18 is It is a gap portion formed between the resin mold 15 and the discharge resistor 13.

The dry capacitor 11 with a built-in discharge resistor is
One or a plurality of capacitor elements 12 and a discharge resistor 13 whose entire surface is coated with a fluorine-based releasing agent 17 are connected in parallel with a lead wire 14, and an external lead-out terminal 16 is connected to the tip of the lead wire 14. And then store it in a casting mold (not shown),
After vacuum drying, a thermosetting resin such as an epoxy resin or a polyester resin was injected into the casting mold and cured by heating to form a resin mold 15, which was then taken out of the casting mold to complete the production.

In the manufactured dry capacitor 11 with a built-in discharge resistor, when the fluorine-based mold release agent 17 applied to the entire surface of the discharge resistor 13 is removed as described above, a gap 18 is formed there.

In the dry type capacitor 1 with a built-in discharge resistor of the embodiment shown in FIGS. 1 and 2, the discharge resistor 3 is housed in an insulating container 7 to form a space 8 and the dry type capacitor 11 with a built-in discharge resistor is a discharge resistor. A fluorine-based mold release agent 17 is applied to the container 13 to form a gap 18, and the space 8 and the gap 18 prevent the discharge resistors 3 and 13 from directly contacting the resin molds 5 and 15. However, it is possible to avoid physical stress such as heat-curing shrinkage and thermal deformation during the thermal cycle test.

Since the leads 4 and 14 for connection are coated with a release agent such as silicon, resin can be prevented from entering through the lead wires due to surface tension.

Next, the discharge resistor 3 shown in FIG. 1 of the above embodiment.
2 is housed in an insulating container 7 to form a space portion 8, and a dry-type capacitor A with a built-in discharge resistor according to the present invention, and the discharge resistor 13 shown in FIG. The following thermal shock test was performed on the dry capacitor B with a built-in discharge resistor of the present invention and the conventional dry capacitor C with a built-in discharge resistor shown in FIG. 3, and then an AC voltage of 3810 V was applied for 1 minute to measure the discharge resistance value. , The resistance value after the thermal shock test is less than the specified value −5% with respect to the resistance value before the thermal shock test.
Table 1 shows the result of quality of whether or not the range of + 5% is satisfied.

[0015]

[Table 1]

As is apparent from Table 1, the number of non-defective products in which the resistance value after the test satisfies the specified value range of -5% to + 5% with respect to the resistance value before the test is the conventional dry capacitor C with a built-in discharge resistor. In the case of, the test conditions drastically decrease as the test conditions become stricter, but in the case of the dry capacitors A and B with built-in discharge resistors of the present invention, even if the test conditions become strict, 9 or 10 out of 10 tests are good products. There is almost no reduction.

Therefore, the dry capacitors A and B having a built-in discharge resistor of the present invention have a better thermal shock than the conventional dry capacitor C having a built-in discharge resistor, and the improvement effect is remarkable.

[0018]

As described above, in the dry capacitor with a built-in discharge resistor of the present invention, the discharge resistor is housed in an insulating container, and a fluorine-based spacer is provided on the space between the discharge resistor and the resin mold or on the surface of the discharge resistor. A mold agent is applied to form a gap between the discharge resistor and the resin mold, so that the discharge resistor and the resin mold do not come into direct contact with each other. Prevents cracks from occurring on the surface of the discharge resistor due to stress caused by the difference in thermal expansion and contraction rates between the mold resin and the discharge resistor, and significantly reduces the withstand voltage performance of the discharge resistor and changes in resistance value.
Furthermore, it is possible to avoid physical stress such as thermal deformation during the cold heat cycle test, to obtain long-term quality stability of the discharge resistor, and to contribute to the quality stabilization of the dry capacitor with a built-in discharge resistor, which can be used industrially and practically. It is of great value.

[Brief description of drawings]

FIG. 1 is an embodiment of a dry capacitor with a built-in discharge resistor according to the present invention, (A) is an internal circuit configuration diagram, and (B) is an enlarged view of a main part.

2A and 2B are another embodiment of the dry capacitor with a built-in discharge resistor of the present invention, FIG. 2A is an internal circuit configuration diagram, and FIG.

FIG. 3 shows a conventional dry capacitor with a built-in discharge resistor (A).
Is an internal circuit configuration diagram, and (B) is an enlarged view of a main part.

[Explanation of symbols]

 1: Dry capacitor with built-in discharge resistance 2: Capacitor element 3: Discharge resistor 4: Silicon-coated lead wire 5: Resin mold 6: External lead terminal 7: Insulation container 8: Space 11: Dry capacitor with built-in discharge resistance 12: Capacitor element 13: Discharge resistor 14: Lead wire coated with silicon 15: Resin mold 16: External lead terminal 17: Fluorine-based release agent 18: Gap 21: Dry capacitor with built-in discharge resistance 22: Capacitor element 23: Discharge resistance Container 24: Lead wire coated with silicon 25: Resin mold 26: Terminal for external drawing

Claims (2)

[Claims] 1. A dry capacitor with a built-in discharge resistor, wherein one or a plurality of capacitor elements and a discharge resistor are connected in parallel and molded with a resin. The discharge resistor is housed in an insulating container, and the discharge resistor and the mold are molded. A dry capacitor with a built-in discharge resistor, characterized in that a space is formed between it and the resin. 2. A dry capacitor with a built-in discharge resistor, wherein one or a plurality of capacitor elements and a discharge resistor are connected in parallel and resin-molded, and a release agent is applied to the entire surface of the discharge resistor. A dry capacitor with a built-in discharge resistor, characterized in that a gap is formed between the discharge resistor and the molding resin by resin molding.