JPH0533519U - High voltage capacitor and magnetron - Google Patents

Abstract

(57) [Abstract] [Purpose] Peeling, gaps, cracks, etc. due to thermal stress are unlikely to occur at the contact interface between the dielectric ceramic body and the insulating resin,
Provide a highly reliable high-voltage capacitor and magnetron. [Structure] A grounding metal 1, through capacitors 20, 30, through conductors 4, 5, outer insulating resin (71, 72), inner insulating resin (81, 82), and insulating tubes 10, 11.
Outer insulating resin (71, 72) and inner insulating resin (81,
82), at least one of which is made of urethane resin, is filled around the feedthrough capacitors 20 and 30, and is in close contact with the surface of the dielectric ceramic body 200 or 300. The insulating tubes 10 and 11 are the through holes 201 of the through conductors 4 and 5,
It is provided so as to cover the portion located at 301.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetron having a high voltage capacitor and a filter including the high voltage capacitor.

[0002]

[Prior Art]

 Conventional high voltage capacitors of this type are well known, for example, in Japanese Utility Model Publication No. 1-19388 and Japanese Utility Model Publication No. 63-48112. The basic structure is that two through-holes are formed at intervals in the dielectric porcelain body that constitutes the through-capacitor, and on both sides where the through-holes are opened Common electrode, and fix the common electrode on the floating part of the grounding metal by soldering or the like, and also penetrate the through conductor through the through hole of the feedthrough capacitor and the through hole of the grounding metal. The structure is such that this through conductor is soldered onto the individual electrode of the through capacitor using an electrode connecting body or the like. For the grounding metal fitting, project the floating portion on one side, insert an insulating case around the floating portion so as to surround the feedthrough capacitor, and surround the through conductor on the other side. , The insulation cover is attached. A thermosetting insulating resin such as an epoxy resin is filled inside and outside the insulating case and the feedthrough capacitor surrounded by the insulating case to ensure moisture resistance and insulation.

[0003]

[Problems to be solved by the device]

 In this type of high-voltage capacitor, in order to ensure reliability, it is possible to increase the adhesive strength between the dielectric ceramic body that constitutes the feedthrough capacitor and the insulating resin filled around it. Extremely important. However, conventional high-voltage capacitors have an adhesive strength of approximately 20-40 kg / cm2 in the measurement temperature range of 80-140 ° C, and the thermal stress generated during heat shock tests, heat cycle tests, or temperature fluctuations during use. Therefore, it was not possible to prevent the occurrence of peeling, gaps or cracks at the contact interface between the dielectric ceramic body and the insulating resin. Therefore, when used in a high temperature and high humidity environment such as a reliability test of a high temperature load test or a humidity resistance load test, or as a filter for a magnetron of a microwave oven, it is insulated from the dielectric ceramic body. There is a problem in that moisture penetrates into the peeling, gaps, or cracks that occur at the contact interface with the resin, and the electric field concentrates, causing voltage breakdown.

Therefore, an object of the present invention is to solve the above-mentioned conventional problems and to prevent peeling, gaps or cracks due to thermal stress at the contact interface between the dielectric ceramic body and the insulating resin. It is to provide a high-voltage capacitor and a magnetron that are highly reliable and reliable.

[0005]

[Means for Solving the Problems]

 In order to solve the above problems, a high voltage capacitor according to the present invention is a high voltage capacitor having a grounding metal, a through capacitor, a through conductor, an insulating tube, and an insulating resin. The metal fitting has a floating portion on one surface side, and the floating portion has a hole.The through capacitor has a through hole in the dielectric porcelain body and is formed on both sides of the through hole. An electrode is disposed on the floating portion, one of the electrodes is fixed to the floating portion, and the through conductor penetrates the through hole and the hole and is provided on the other side of the electrode. Conductive connection is made, the insulating tube is made of a resin having elasticity, and is provided so as to cover a portion of the through conductor located inside the through hole, and the insulating resin is an outer insulating resin. And an inner insulating resin, and at least one Is made of urethane resin, the outer insulating resin is filled around the feedthrough capacitor on the one surface side of the grounding fitting, and the inner insulating resin is filled in the through hole of the feedthrough capacitor on the other surface of the grounding fitting. It is characterized by being done.

The magnetron according to the present invention is characterized by having the high voltage capacitor.

[0007]

[Action]

 Since at least one of the outer insulating resin and the inner insulating resin is made of urethane resin, the heat cycle test is performed on at least one side filled with urethane resin due to the elasticity of the urethane resin and the adhesion to the dielectric ceramic body. In a heat shock test or heat stress during use, peeling, gaps or cracks are less likely to occur at the contact interface between the dielectric ceramic body of the feedthrough capacitor and the insulating resin, and high temperature load tests and moisture resistance Reliability is significantly improved when used in reliability tests such as load tests or when used in hot and humid environments.

Since the insulating tube is made of a resin having elasticity and is provided so as to cover the portion of the through conductor located inside the through hole, when the inner insulating resin is made of urethane resin, the insulating tube is The elasticity of (1) acts synergistically with the elasticity of the urethane resin, and peeling or the like is further less likely to occur at the contact interface between the dielectric ceramic body and the insulating resin.

[0009]

【Example】

 FIG. 1 is a front sectional view of a high voltage capacitor according to the present invention. In the figure, 1 is a grounding metal, 20 and 30 are feedthrough capacitors, 4 and 5 are feedthrough conductors, 6 is an insulating case, 71 and 72 are outer insulating resins, 81 and 82 are inner insulating resins, 9 is an insulating cover, 10 Reference numeral 11 is an insulating tube made of a silicone tube or the like.

The grounding fitting 1 has floating portions 101 and 102 on one surface side, and the floating portions 101 and 102 have holes 103 and 104. The feedthrough capacitors 20 and 30 have through holes 201 and 301 in the dielectric ceramic bodies 200 and 300, and electrodes (202, 203) and (302, 303) on both sides of the through holes 201 and 301, respectively. Then, the electrodes 203 and 303 are arranged on the floating portions 101 and 102, and the electrodes 203 and 303 are fixed to the floating portions 101 and 102 by means such as soldering. The through conductors 4 and 5 penetrate through the through holes 201 and 301 and the holes 103 and 104, and are electrically connected to the electrodes 202 and 302 through the electrode connecting bodies 12 and 13. At least one of the outer insulating resin (71, 72) and the inner insulating resin (81, 82) is a urethane resin. The outer insulating resin (71, 72) is made of a thermosetting resin such as an epoxy resin or an unsaturated polyester resin, and is filled around the feedthrough capacitors 20, 30 on one surface side of the grounding metal 1, and the dielectric ceramic body 200. , 300 is in close contact with the surface. The inner insulating resin (81, 82) is made of urethane resin, and is filled in the through holes 201, 301 of the through capacitors 20, 30 on the other surface of the grounding metal 1, and is attached to the surface of the dielectric ceramic body 200, 300. It is in close contact. The insulating tubes 10 and 11 are provided so as to cover the portions of the through conductors 4 and 5 located in the through holes 201 and 301, respectively.

With the above structure, the elasticity of the urethane resin itself and the dielectric porcelain of the urethane resin at the contact interface between the inner insulating resin (81, 82) and the dielectric porcelain 200, 300. Due to the adhesion to the body 200, 300, peeling, gaps or cracks due to heat cycle test, heat shock test or heat stress during use are less likely to occur, and reliability test such as high temperature load test or moisture resistance load test or Reliability is significantly improved when used in high temperature and high humidity environments. Furthermore, the elasticity of the insulating tubes 10 and 11 act synergistically with the elasticity of the urethane resin, and the contact interface between the dielectric ceramic elements 200 and 300 and the inner insulating resin (81, 82). It is difficult for peeling to occur in one layer.

Although not shown, when the outer insulating resin (71, 72) is made of urethane resin, the contact interface between the outer insulating resin (71, 72) and the dielectric ceramics 200, 300 is similarly formed. In the above, due to the elasticity of the urethane resin itself and the adhesiveness of the urethane resin to the dielectric ceramic elements 200 and 300, peeling, gaps or cracks due to heat cycle test, heat shock test or thermal stress during use may occur. The reliability is significantly improved, such as reliability tests such as high temperature load tests and humidity resistance load tests, or when used in high temperature and high humidity environments.

FIG. 2 is a diagram showing a high temperature load test result. In the high temperature load test, the product of the present invention and the conventional product were appropriately sampled, and a high voltage of DC 15 kV was applied under the temperature condition of 120 ° C. In the product of the present invention, the outer insulating resin (71, 72) and the inner insulating resin (81, 82) are made of urethane resin. As shown in FIG. 2, the conventional product has a cumulative failure rate of 90% at 3500 hours, whereas the product of the present invention has a cumulative failure rate of 90% at 7,000 hours, which is about double the life. ..

FIG. 3 is a diagram showing the results of the heat shock test. In the heat shock test, the product of the present invention and the conventional product are appropriately extracted, and a heat shock of 120 ° C. for 1 hour and −40 ° C. for 1 hour is given every 10 cycles. A withstand voltage test was performed to check whether there was electrical breakdown that might be caused by peeling or the like. As shown in FIG. 3, the conventional product has a cumulative failure rate of 90% at 350 cycles, whereas the product of the present invention has a cumulative failure rate of 90% at 100 cycles, which is about three times the life. ..

FIG. 4 is a diagram showing the results of the moisture resistance test. In the moisture resistance test, the product of the present invention and the conventional product are appropriately sampled and left in a temperature of 40 ° C. and a humidity of 90 to 95% RH to obtain 240, 500, 1000, 1500, 2000, 3000, 4000, 5000. A withstand voltage test was conducted at intervals of time, and it was checked whether or not there was an electrical breakdown that might be caused by peeling or the like. As shown in FIG. 4, the conventional product failed at 1500 and 2000 hours, but the device of the present invention did not fail at 5000 hours.

From the above results, it is verified that the reliability test such as the high temperature load test and the humidity resistance test or the reliability when used in a high temperature and high humidity environment is significantly improved.

Next, other parts shown in FIG. 1 will be described. The grounding metal fitting 1 has two floating portions 101 and 102 on the same surface side, and each of the floating portions 101 and 102 has holes 103 and 104 in the central portion and is spaced from each other. . There are two penetrating capacitors 20 and 30, each of which has through holes 201 and 301 in the dielectric ceramic body 200 and 300, and electrodes (202 and 203) on both sides of the through holes 201 and 301, respectively. (302, 303) is arranged on the floating portions 101, 102, and the electrodes 203, 303 are fixed to the floating portions 101, 102 by means such as soldering. The through conductors 4 and 5 are provided so as to penetrate through the through holes 201 and 301 for each of the through capacitors 20 and 30, and are respectively electrically connected to the electrodes 202 and 302. The penetrating conductors 4 and 5 penetrate through the holes 103 and 104 provided in the floating portions 101 and 102 of the grounding fitting 1 in a non-contact state, and both ends are led out to the outside.

As described above, the grounding metal fitting 1 has the two floating portions 101 and 102 on the same surface side, the number of the feedthrough capacitors 20 and 30 is two, and the throughholes 201 and 301 are respectively provided. In addition to having the electrodes (202, 203), (302, 303) on both sides of the through holes 201, 301, the electrodes 202, 302 are arranged on the floating portions 101, 102 so that the electrodes 202, 302 have the floating portions. The penetrating conductors 4 and 5 are fixed to 101 and 102 and penetrate the through holes 201 and 301 for the penetrating capacitors 20 and 30, respectively, and are respectively electrically connected to the electrodes 202 and 302. Therefore, it becomes a capacitor-independent high-voltage capacitor. Compared with a dual high-voltage capacitor, it is less likely to have poor voltage resistance, and is smaller and less expensive.

The insulating case 6 has two tubular portions 61 and 62, the tubular portions 61 and 62 are juxtaposed at a distance D1 from each other, and the upper opening sides of the tubular portions 61 and 62 are connected to each other by a connecting portion 64. Further, it has a concave portion 63 connected to the inner diameter portions 611 and 621, the lower opening side is attached to the outer periphery of the floating portions 101 and 102, and the penetration capacitors 20 and 30 are housed in the inner diameter portions 611 and 621. The outer insulating resin (71, 72) is filled around the feedthrough capacitors 20, 30 inside the inner diameter portions 611, 621, and the inner insulating resin (81, 82) is provided on the opposite side with the grounding metal fitting 1 interposed therebetween. In the area surrounded by the cover 9, the through holes 201 and 301 of the through capacitors 20 and 30 are filled.

As described above, the insulating case 6 has the two tubular portions 61 and 62, and the feedthrough capacitors 20 and 30 are housed in the inner diameter portions 611 and 621 of the outer insulating resin (71). , 72) are filled around the feedthrough capacitors 20, 30 inside the inner diameter portions 611, 621, so that the outer insulating resin (71, 72) is substantially independent between the cylindrical portions 61-62. In addition to this, in the insulating case 6, the tubular portions 61 and 62 are provided side by side with a distance D1 therebetween, and the space generated between the tubular portions 61 and 62 serves as a heat radiation area. For this reason, the heat stress generated by the heat cycle test, the heat shock test, or the temperature fluctuation in the use state becomes small, and the outer insulating resin (71, 72) and the dielectric ceramic body 200, 300 caused by the heat stress are reduced. Peeling, gaps or cracks are less likely to occur at the contact interface between the and.

The insulating case 6 has two tubular portions 61 and 62, the tubular portions 61 and 62 are provided side by side with a distance D 1 between them, and the upper opening sides of the tubular portions 61 and 62 are connected to each other by a connecting portion 64. Further, it has a concave portion 63 connected to the inner diameter portions 611 and 621, the lower opening side is attached to the outer periphery of the floating portions 101 and 102, and the penetration capacitors 20 and 30 are housed in the inner diameter portions 611 and 621.

In the insulating case 6, the upper opening sides of the tubular portions 61 and 62 are connected to each other by the connecting portion 64, and the lower opening sides are attached to the outer peripheries of the floating portions 101 and 102. As a result, an assembled structure can be obtained in which they are integrally connected. Therefore, mechanical reinforcement of the feedthrough capacitors 20 and 30 and the feedthrough conductors 4 and 5 housed inside the tubular portions 61 and 62 is increased, and the feedthrough conductors 4 and 5 are less likely to suffer from a graze. As a result, interfacial peeling is less likely to occur between the through conductors 4, 5, the through capacitors 20, 30, and the grounding metal 1, and the outer insulating resin (71, 72), and the withstand voltage characteristics are improved.

Since the insulating case 6 has the concave portion 63 which is continuous with the inner diameter portions 611 and 621, the outer insulating resin (71, 72) can be simultaneously poured into the two cylindrical portions 61, 62 through the concave portion 63. As a result, the number of insulating resin casting steps is halved, and costs are reduced.

The insulating cover 9 also has two tubular portions 91 and 92, the tubular portions 91 and 92 are provided side by side with a distance D 2 between them, and the lower opening sides of the tubular portions 91 and 92 are connected to each other by the connecting portion 94. In addition, there is a concave portion 93 which is continuous with the inner diameter portions 911 and 921, and the upper opening side is inserted and attached to the inner circumference of the floating portions 101 and 102. The inner insulating resin (81, 82) is filled in the inner diameter portions 911, 921. The structure of the insulating cover 9 is similar to that of the insulating case 6, and the same operation and effect as described with respect to the insulating case 6 can be obtained.

The present invention can be widely applied to high voltage capacitors having various structures. Examples thereof are shown in FIGS.

First, in FIG. 5, the outer peripheral surfaces of the outer insulating resin 7 and the inner insulating resin 8 form a frame partitioning the space. Therefore, the outer insulating resin 7 and the inner insulating resin 8 serve as an outer package, and the insulating case and insulating cover, which have been essential in the past, do not exist. With such a structure, the expansion / contraction motion of the outer insulating resin 7 and the inner insulating resin 8 based on the insulating case and the insulating cover is prevented in a heat shock test, a heat cycle test, or a temperature change in a use state, It is possible to prevent peeling, gaps, or cracks from occurring at the contact interfaces between the dielectric ceramic body 200, 300 and the outer insulating resin 7 and the inner insulating resin 8. Further, since the insulating case and the insulating cover are not necessary, the number of parts and the number of assembling steps are reduced, and the cost is reduced. The outer insulating resin 7 and the inner insulating resin 8 can be formed by injection molding.

In FIG. 6, the partition member 73 is arranged between the feedthrough capacitors 20-30 inside the outer insulating resin 7. Polypropylene or the like is suitable for the partition member 73 when the outer insulating resin 7 is an epoxy resin. With such a structure, the outer insulating resin 7 is divided into the feedthrough capacitor 20 side and the feedthrough capacitor 30 side, and stress interaction is reduced, so that the feedthrough capacitors 20, 30 and the outer insulating resin 7 are separated from each other. It is possible to more effectively prevent peeling, gaps or cracks at the contact interface between them.

In FIG. 7, in a basic structure similar to that of the embodiment of FIG. 1, the connecting portion 64 of the insulating case 6 is embedded inside the outer insulating resin 7.

FIG. 8 shows an example using one feedthrough capacitor. High voltage capacitors having such a structure are well known in the art. The feedthrough capacitor 2 has two through holes 211 and 212 formed in the dielectric porcelain body 210 at intervals, and the individual electrodes 213 and 214 which are independent from each other are formed on both sides of the through holes 211 and 212 which are opened. A common electrode 215 that is common to the individual electrodes 213 and 214 is provided, and the common electrode 215 is fixed to the floating portion 111 of the grounding metal fitting 1 by means such as soldering. Then, the penetrating conductors 4 and 5 are penetrated through the penetrating holes 211 and 212 of the penetrating capacitor 2 and the 112 provided in the floating portion 111 of the grounding metal 1, and the penetrating conductors 4 and 5 are connected to the penetrating capacitor 2 of the penetrating capacitor 2. It has a structure in which the individual electrodes 213 and 214 are soldered using the electrode connecting bodies 12 and 13. In the grounding metal 1, the floating portion 111 is projected on one surface side, the insulating case 6 is attached to the outer periphery of the floating portion 111 so as to surround the feedthrough capacitor 2, and the other surface side is An insulating cover 9 is attached so as to surround the through conductors 4 and 5.

In FIG. 9, as in the embodiment of FIG. 5, the outer peripheral surfaces of the outer insulating resin 7 and the inner insulating resin 8 form a contour that divides the space. Therefore, the action and effect as described in FIG. 5 can be obtained.

FIG. 10 is a partial cross-sectional view of a magnetron incorporating a high voltage capacitor according to the present invention as a filter, wherein 15 is a cathode stem, 16 is a filter box, 17 and 18 are inductors, and 19 is inductors 17 and 18. The high-voltage capacitor according to the present invention is used together with it as a filter. The filter box 16 is arranged so as to cover the cathode stem 15, and the high voltage capacitor 19 is passed through a through hole provided in the side plate 161 of the filter box 16 so that the outer insulating resin 7 is exposed to the outside. It is provided and fixed to the side plate 161 of the filter box 16 at the portion of the grounding metal 1. The inductors 17 and 18 are connected in series inside the filter box 16 between the cathode terminal of the cathode stem 15 and the through conductors 4 and 5 of the high-voltage capacitor 19. 21 is a cooling fin, 22 is a gasket, 23 is an RF output end, and 24 is a magnet.

[0032]

[Effect of the device]

 As described above, according to the present invention, the following effects can be obtained. (A) In a high-voltage capacitor, at least one of the outer insulating resin and the inner insulating resin is made of urethane resin. Therefore, at least one side filled with the urethane resin has the elasticity of the urethane resin and the adhesion to the dielectric ceramic body. , Heat cycle test, heat shock test, or peeling, gap or crack at the contact interface between the dielectric ceramic body of the feedthrough capacitor and the insulating resin due to heat stress during use, etc. It is possible to provide a high-voltage capacitor and a magnetron whose reliability is significantly improved, such as a reliability test such as a humidity resistance test or when used in a high temperature and high humidity environment. (B) The insulating tube is made of a resin having elasticity and is provided by covering the portion of the through conductor located in the through hole. Therefore, when the inner insulating resin is made of urethane resin, the insulating tube is It is possible to provide a high-voltage capacitor and a magnetron in which the elasticity of the resin acts synergistically with the elasticity of the urethane resin, and peeling or the like is less likely to occur at the contact interface between the dielectric ceramic body and the insulating resin.

[Brief description of drawings]

FIG. 1 is a front sectional view of a high voltage capacitor according to the present invention.

FIG. 2 is a diagram showing a high temperature load test result of a device of the present invention and a conventional product.

FIG. 3 is a diagram showing a heat shock test result of the product of the present invention and the conventional product.

FIG. 4 is a diagram showing the results of a moisture resistance test of a product of the present invention and a conventional product. 5 to 9 are cross-sectional views of different embodiments of the high voltage capacitor according to the present invention.

FIG. 10 is a partial cutaway view of a magnetron incorporating a high voltage capacitor according to the present invention.

[Explanation of symbols]

1 Grounding Metal 101, 102, 111 Floating part 103, 104, 112 Hole 2, 20, 30 Through capacitor 201, 301, 211, 212 Through hole 202, 203, 213, 214, 215 Electrode 302, 303 Electrode 4, 5 Through conductor 7, 71, 72 Outer insulating resin 8, 81, 82 Inner insulating resin 9 Insulating cover 10, 11 Insulating tube
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 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isao Fujiwara 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation

Claims (5)

[Scope of utility model registration request] 1. A high voltage capacitor having a grounding metal fitting, a feedthrough capacitor, a feedthrough conductor, an insulating tube, and an insulating resin, wherein the grounding metal fitting has a floating portion on one surface side, The floating portion has a hole, the feedthrough capacitor has a through hole in the dielectric porcelain body, has electrodes on both sides of the through hole, and is disposed on the floating portion. One of the electrodes is fixed to the floating portion, the through conductor penetrates through the through hole and the hole, and is conductively connected to the other of the electrode, and the insulating tube is elastic. Made of a resin having a property of covering the portion of the through conductor located in the through hole, the insulating resin includes an outer insulating resin and an inner insulating resin, at least one of which is a urethane resin. The outer insulating resin Filled around the feedthrough capacitor in said one side of the bracket, the high voltage capacitor in which the inner insulating resin is characterized in that it is filled in the through hole of the feedthrough capacitor in the other surface of the grounding member. 2. The high voltage capacitor as claimed in claim 1, wherein the insulating tube is made of silicone rubber. 3. The grounding fitting includes two floating portions, each of which is arranged at a distance from each other, and there are two feedthrough capacitors, each of which is arranged on the floating portion. The through conductor is provided so as to penetrate through the through hole for each of the through capacitors, each of which is individually electrically connected to the other of the electrodes, and the outer insulating resin is provided for each of the through capacitors. The high-voltage capacitor according to claim 1 or 2, wherein the high-voltage capacitors are filled independently of each other. 4. An insulating case, the insulating case comprising:
There are two tubular portions, the tubular portions are juxtaposed at a distance from each other, the upper opening side of the tubular portion has a recess connected to the inner diameter portion, and the lower opening side is the upper end side of the outer insulating resin. The high-voltage capacitor according to claim 1, wherein the high-voltage capacitor is attached to the outer periphery. 5. A magnetron having a filter composed of a high voltage capacitor, wherein the high voltage capacitor is one of claim 1, claim 2, claim 3 or claim 4. Magnetron.