JP2002140996A - Inverter and magnetron integrated unit, and circuit board for mounting them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save space, reduce number of component items and wiring cables, improve an insulating property and heat dissipation, and reduce assembling man-hour, in a power circuit board used for a dryer for drying foods with a microwave oven or micro wave, a luminaire for lighting an electrodeless arc tube with the micro wave, an air conditioner, a refrigerator, a rice cooker, or the like. SOLUTION: An inverter 19 and a magnetron 21 are arranged on the circuit board 22 so that the inverter 19 is windward of an axial fan 20 and the magnetron 21 is downwind. A lead frame 28 of the circuit board 22 is coated with resin 29. A choke coil 40 is formed by alternately bending the lead frame 28 like zigzag, a capacitor 41 is formed of an electrode having a partially extended circuit pattern and a dielectric film 46, and a radiator plate 48 is formed by partially extending, bending, and raising the circuit pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dryer for drying food in a microwave oven or a microwave, a lighting device for lighting an electrodeless arc tube by a microwave, and a power circuit used in an air conditioner, a refrigerator, a rice cooker and the like. The present invention relates to an inverter mounted on a circuit board as a unit integrating an inverter and a magnetron, a magnetron integrated unit, and a circuit board for mounting the same.

[0002]

2. Description of the Related Art Conventionally, a microwave oven inverter, a fan and a magnetron are shown in a rear view of a microwave oven main body.
As shown in FIG. In FIG. 29, 1 is an inverter, 2 is a magnetron and inverter 1
DC voltage of 4000 volts generated by the high voltage cable 3
Is applied to the magnetron 2 to oscillate a high frequency of 2450 MHz to guide the food through the waveguide into the chamber to heat the food.
A fan 4 is arranged to generate about 100 W of heat from the inverter 1, and a fan 5 is arranged to generate about 400 watts of heat from the magnetron 2.

FIG. 30 is a side view of the magnetron 2 and FIG.
Is a wiring diagram of a magnetron. 30 and 31, 6 is a core tube which is a bipolar vacuum tube, 7 is a cathode,
8 is an antenna. DC 40 between cathode 7 and ground
High frequency energy is extracted from the antenna 8 by applying 00 volts to oscillate high frequency. Since the cathode 7 is in the working space in the core tube 6, part of the high-frequency energy leaks along the lead wire of the cathode 7. In order to prevent radio wave leakage, a noise filter is provided by the choke coil 9 and the feedthrough capacitor 10. Since the core tube 6 generates about 400 W of heat, the radiator 1
1 is provided.

Conventionally, as a circuit board used for a power circuit, one described in Japanese Patent Application Laid-Open No. Hei 10-270810 is known. FIG. 32 shows the structure of a conventional circuit board, in which a metal wiring pattern 12, a plurality of electronic components 13, and a heat sink 14 bent from the wiring pattern 12 are raised.
And a reinforcing sheet 15 attached to the wiring pattern 12. In addition, in the conventional power circuit, a heat radiating plate 17 is provided on the high heat generating component 16 as shown in FIG.
6 was attached to the lead 18.

[0005]

In the inverter and magnetron unit and the circuit board on which they are mounted, space saving, a reduction in the number of parts, a reduction in the number of wiring cables, a high insulation property, a high heat dissipation, and a reduction in the number of assembly steps are required. Reduction is required.

[0006] The present invention saves space, reduces the number of parts,
An object of the present invention is to provide an inverter and a magnetron integrated unit and a circuit board for mounting the same, which can reduce the number of wiring cables, high insulation properties, high heat dissipation, and the number of assembly steps.

[0007]

According to a first aspect of the present invention, there is provided an inverter for oscillating a magnetron, a cooling fan, and a magnetron. It has the effect of saving space, reducing the number of parts, reducing the number of wiring cables, and reducing the number of assembly steps.

According to a second aspect of the present invention, in the above configuration, an inverter is provided on the windward side of the cooling fan, and a magnetron is provided on the leeward side of the cooling fan. And the number of assembly steps is reduced.

According to a third aspect of the present invention, in the configuration of the first aspect, the magnetron is mounted on a circuit board of the inverter, and has an effect of reducing wiring cables and man-hours for assembling.

According to a fourth aspect of the present invention, in the configuration according to the third aspect, the circuit board has a configuration in which a metal lead frame is covered with an insulating resin.
It has the effect of reducing the number of parts, reducing the number of wiring cables, high insulation, high heat dissipation, and reducing the number of assembly steps.

According to a fifth aspect of the present invention, in the configuration of the fourth aspect, a choke coil of a noise filter for preventing a radio wave returning from the magnetron to the inverter side is formed by alternately cutting and raising a lead frame. It has the effect of saving space, reducing the number of parts, reducing the number of wiring cables, high insulation, high heat dissipation, and reducing the number of assembly steps.

According to a sixth aspect of the present invention, there is provided a circuit board in which a metal lead frame according to the fourth aspect is covered with an insulating resin. The other electrodes are opposed to each other via a via, and the outside thereof is resin-molded to produce a capacitor, which has the effect of saving space, reducing the number of parts, and reducing the number of assembly steps.

According to a seventh aspect of the present invention, in the configuration of the third aspect, the noise filter capacitor for preventing a radio wave returning from the magnetron to the inverter side, and the circuit board of the sixth aspect. It has the effect of saving space, reducing the number of parts, and reducing the number of assembly steps.

According to an eighth aspect of the present invention, the metal lead frame is resin-molded so as to be covered with an insulating resin.
In the described circuit board, a part of the circuit pattern is expanded and this expanded part is bent and raised to form a heat sink, which has the effect of saving space, reducing the number of parts, high heat dissipation, and reducing the number of assembly steps. Have.

According to a ninth aspect of the present invention, in the circuit board according to the eighth aspect, the metal lead frame near the component to be mounted is bent and raised to form a heat sink, thereby saving space and reducing the number of components. It has the effect of high heat dissipation and a reduction in the number of assembly steps.

According to a tenth aspect of the present invention, in the circuit board according to the eighth aspect, the metal lead frame below the component to be mounted is bent and raised to form a heat sink, thereby saving space and reducing the number of components. It has the effect of high heat dissipation and a reduction in the number of assembly steps.

According to an eleventh aspect of the present invention, in an inverter integrated with an inverter power supply for oscillating a magnetron, a cooling fan, and a magnetron, and in a magnetron integrated unit, circuit components constituting the inverter power supply are assembled. Classified into blocks, having a divided mounting circuit board in which the circuit components are mounted and wired on a wiring pattern, and a self-heating semiconductor having a fixed heat dissipation plate via a heat dissipation grease or a heat dissipation sheet, A component having a wiring pattern of a conductive material for arranging the divided mounted circuit boards on a straight line and mechanically and electrically connecting and joining the components, and having a certain size on the inner surface of the mounted circuit board comes. The cooling fan, the inverter, and the magnetron are arranged in this order by bending vertically to the And, a mounting circuit board and the outer board of the three-dimensional structure provided with an inverter, which magnetron is configured to be disposed downwind, space saving, high heat radiation, the effect of reducing the assembling steps.

According to a twelfth aspect of the present invention, in the configuration according to the eleventh aspect, an inverter, a cooling fan, and a magnetron are arranged in this order, and the inverter is located on the windward side.
The magnetron is arranged on the leeward side.

The invention according to claim 13 is the invention according to claims 11 and 1
3. In the configuration described in 2, the heat-dissipating plate on which the self-heating semiconductor of the inverter unit is fixed is provided on a part of a metal housing of the exterior of the unit by heat-dissipating grease or a heat-dissipating sheet, or an insulating plating such as alumite on the metal housing. And has a function of high heat dissipation.

The invention according to claim 14 is the invention according to claims 11 and 1
2. In the configuration described in 2, the mounting circuit board having a three-dimensional configuration has a configuration in which a metal lead frame is covered with an insulating resin, and has a function of high insulation.

According to a fifteenth aspect of the present invention, in the configuration of the fourteenth aspect, a part of the inverter circuit and the magnetron are mounted on the same circuit board in which a metal lead frame is covered with an insulating resin. Yes, it has the effect of high insulation and elimination of assembly man-hours.

The invention according to claim 16 is the invention according to claims 11 and 1
In the configurations described in 2, 13, and 15, a part of a circuit board having a three-dimensional configuration is formed of a phenol resin copper-clad laminated board or a glass epoxy copper-clad laminated board, and the connection between the circuit boards is performed using lead wires. It is configured to perform electromechanical connection by soldering, wire connection via a connector, soldering of a plated metal wire, or the like, and has an effect of cost reduction.

According to a seventeenth aspect of the present invention, in the configuration of the eleventh to sixteenth aspects, the radiator plate of the self-heating semiconductor is attached at an angle to the wind direction of the cooling fan.

The invention according to claim 18 is an inverter / magnetron integrated unit in which an inverter power supply for oscillating a magnetron, a cooling fan and a magnetron are integrated on a circuit board in the same plane, and supplied from the cooling fan. The wind that flows only to the structure that contributes to the cooling of the magnetron, and the airflow that hits only the heater terminal at the end of the tube where the effect of heat conducted from the magnetron tube below the magnetron is small. A heat-insulating heat-resistant resin material structure to be separated is placed in the space of the inverter section, and the wind that has passed through the structure that contributes to cooling the magnetron is separated from the wind that has passed through the inverter heating section and the heater terminal section below the magnetron. High heat dissipation with a structure in which a heat-resistant heat-resistant resin material structure It has the effect of.

According to a nineteenth aspect of the present invention, in the configuration of the eighteenth aspect, a motor portion of the fan, a fan A, an inverter portion, a fan B, and a magnetron are arranged in this order, and a bearing portion of the fan A is provided inside the motor. The bearing portion of the fan B is provided near the fan B, and the fan A and the fan B are connected by a metal propeller shaft, and have a function of high heat radiation.

According to a twentieth aspect of the present invention, in the configuration according to the nineteenth aspect, an inclined heat-resistant resin partition plate is provided on the fan B side of the inverter section, and the wind coming from the fan A is provided on the outer peripheral portion. A punch hole C is provided, and a fan B is provided near the punch hole C on an outer peripheral portion closer to the fan B than the punch hole C.
And has a high heat radiation property.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an integrated inverter and magnetron unit and a circuit board for mounting the same in each embodiment of the present invention will be described with reference to FIGS.

(Embodiment 1) FIG. 1 shows a cross section of an inverter and a magnetron integrated unit of a household microwave oven, and FIG. 2 shows a plan view thereof. 1 and 2, 19 is an inverter, 20 is an axial fan for cooling, 21
Is a magnetron, which is mounted on the circuit board 22 of the inverter 19 in a line. The direction of the wind is such that the inverter 19 is upwind of the axial fan 20 and the magnetron 21 is the wind of the axial fan 2.
It is downwind of 0. Since the inverter 19 generates about 100 W, it needs to be cooled with air at 40 ° C. or less. The air that has entered through the ventilation holes 24 provided in the housing 23 cools the inverter 19, further merges with the air from the ventilation holes 25 that are provided near the axial fan 20, and is accelerated by the axial fan 20. Later, the radiator 26 of the magnetron 21,
The magnetron 21 is cooled by hitting the core tube 27. Since the heat generated by the magnetron 21 is about 400 W, the air coming out of the magnetron 21 reaches about 100 ° C.
This air helps to heat the food by leading it into the microwave oven (not shown) and helps save energy. The vent hole 25 has a function of lowering the temperature of the air passing through the inverter 19 and lowering the pressure loss. The axial fan 20 also serves to thermally insulate the inverter 19 from the high-temperature magnetron 21. If the fan is arranged on the windward side of the inverter 19, the pressure loss increases, and the effect of the ventilation hole 25 cannot be obtained, which is inconvenient. Further, when the fan is arranged on the lee of the magnetron 21, the axial fan 20 is heated by the air of about 100 ° C., so that the blades of the axial fan 20, the bearing, the motor,
The circuit is damaged and is inconvenient.

The circuit board 22 is formed by covering a lead frame 28 having a circuit pattern formed by etching or pressing a copper plate having a thickness of about 0.5 mm with an insulating resin 29. As the insulating resin, PPS (polyphenylene sulfide) which can be cut off at the high temperature of soldering, liquid crystal polymer, crystalline polystyrene, epoxy resin, diallyl phthalate, and the like are suitable. As a covering method, injection molding or transfer molding in which a lead frame is placed in a mold and resin molding is performed, and hot press molding in which a lead frame is sandwiched between prepregs and heated and compressed and cured. Conventional 0.0
Unlike a printed circuit board in which a 35 mm copper foil is attached to a paper-phenol board and etched, the circuit board 22 can reduce the conductor pattern width and the conductor pattern interval, and thus is effective in saving space. In addition, since it is covered with a resin, the insulation can be improved. Further, since the magnetron 21 is mounted on the circuit board 22, a high-voltage cable as in the conventional example is unnecessary, and the number of components can be reduced.

The schematic configuration of the inverter 19 is AC100
A commercial power supply of ~ 240 V is rectified by the diode bridge 30 and oscillated at several tens KHz using the power transistor 31.
And a control module 34 for controlling the output. The alternating current of about 2000 V is double-rectified by a high-voltage diode 35 and a capacitor (not shown), applied to the magnetron 21, and supplied to the magnetron 21 at 2450 MHz.
High frequency appears.

Since a high voltage is applied to the secondary terminals 36 and 37 of the transformer 33, the creepage distance can be secured by providing the partition 38, so that the insulation can be enhanced. Since the screen 38 can be formed integrally at the same time as the resin molding of the circuit board 22, it is convenient without increasing the cost.

The cathode lead wire 3 of the magnetron 21
9 leaks a part of the high-frequency energy, so that the choke coil 40 and the capacitor 41
Is provided.

Hereinafter, a method of forming the choke coil 40 and the capacitor 41 will be described with reference to FIGS. FIG. 3 is a plan view of a lead frame 28 for forming the choke coil 40 and the capacitor 41, and FIG. 4 is a plan view of the lead frame 28 of FIG. FIG. 5 is FIG.
6, FIG. 6 shows a BB section of FIG. 4, and FIG. 7 shows a CC section of FIG. Referring to FIG.
The coil portion 42 is cut in a zigzag shape, and if the coil portion 42a is alternately bent so that the coil portion 42a is upward and the coil portion 42b is downward, a coil as shown in FIGS. 4 and 5 is obtained. Further, by covering with an insulating resin 29, the coil 40 of FIG. 1 is completed. When the coil 40 is disposed on the end face of the circuit board 22, the coil 4
This is convenient because the ferrite core 43 can be put in the zero and the inductance can be increased.

In FIG. 3, reference numeral 44 denotes an electrode having a part of the circuit pattern widened, and reference numeral 45 denotes another electrode having a part of the circuit pattern widened. As shown in FIGS. 4 and 6, the upper and lower sides of the electrode 44 are sandwiched between dielectric films 46, and the other electrodes 4
5 is bent and sandwiched between the capacitor 4 and the outside thereof is covered with an insulating resin 29.
Becomes 1. As the dielectric film 46, polyethylene terephthalate of about 0.1 mm to 1 mm or PPS resin is suitable. It is convenient to use a dielectric film 46 with a conductor thin film attached to one side, since another electrode 45 having a partly enlarged circuit pattern is not required.

When the end portion 47 of the coil portion 42 shown in FIG. 3 is bent as shown in FIGS. 4 and 7, welding to the cathode lead wire 39 shown in FIG. 1 is facilitated.

In FIG. 1, reference numeral 48 denotes a heat radiating plate for effectively radiating the heat generated by the high voltage diode 35.
Hereinafter, a description will be given with reference to FIGS. FIG. 8 is a plan view of the lead frame 28 for forming the heat sink 48.
FIG. 9 is a plan view of the lead frame 28 of FIG. FIG. 10 is a cross section taken along line DD of FIG. In FIG. 8, reference numeral 49 denotes a circuit pattern, and reference numeral 50 denotes a heat dissipating portion in which a part of the circuit pattern 49 is expanded. Reference numeral 51 denotes a component insertion hole. When the heat radiating portion 50 is bent and raised and covered with the insulating resin 29 as shown in FIGS. 9 and 10, a heat radiating plate 48 is formed.
The high voltage diode 35 can be mounted as shown in FIG. Since the lower lead frame of the high voltage diode 35 is used as a heat sink, space can be saved. As a heat sink, a lead frame 52 near a component to be mounted as shown in FIG. 11 may be bent and raised as shown in FIG. 12, and FIG. 13 is an elevational view of FIG.

The heat sink is made of insulating resin 2 for insulation.
9 may be covered.

(Embodiment 2) FIG. 14 is a plan view of an inverter and a magnetron integrated unit of a household microwave oven. In FIG. 14, 53 is an inverter, 54 is a sirocco fan for cooling, 55 is a magnetron, and 55 is an inverter.
3 is mounted on the circuit board 56. The wind direction is such that the inverter 53 is upwind of the sirocco fan 54 and the magnetron 55 is downwind of the sirocco fan 54. Embodiment 1
The difference is that the fan is a sirocco fan, and the others are the same.

(Embodiment 3) FIG. 15 is a perspective view showing a state in which an inverter and a magnetron integrated unit having a three-dimensional configuration of a home microwave oven are developed in a plane.
FIG. 16 is a perspective view showing a three-dimensional configuration in which each substrate in the state of FIG. 15 is vertically bent. FIG.
In the three-dimensional mounting board shown in FIGS. 23 and 24, a soldered portion of a circuit electrically connected from the back surface of the mounting board comes out on the front surface and has excellent insulating properties in places where electrical insulation is required. FIG. 2 is a perspective view showing a state in which an external housing (top surface, bottom surface) to which a resin sheet or a thin plate-shaped resin is attached is combined. FIG. 18 is a perspective view of an integrated unit of an inverter and a magnetron having a three-dimensional configuration showing an external view in which the external housing shown in FIG. 17 is combined. FIG. 19 shows a typical circuit configuration in the integrated inverter and magnetron unit.

FIG. 20 is a sectional view showing a section A in FIG. 18, and FIG. 21 is a sectional view showing a section B in FIG.
2 is a sectional view showing a C section viewed from above in FIG.

In FIG. 15, reference numeral 61 denotes a magnetron, 62
Is a magnetron noise prevention coil, 63 is a high voltage capacitor (withstands 4 kV), 64 is a high voltage diode, 65
Is a cooling fan, 66 is a current detection sensor, 67 is a high-voltage transformer, 68 is a power element (such as an IGBT), 69 is a diode bridge, 70 is a self-heating semiconductor such as the power element 68 and the diode bridge 69, and heat radiation grease and heat radiation. A metal heat sink attached via a sheet or the like, 76 is a control microcomputer, 77 is a board on which heavy components such as a high-voltage transformer 67 are mounted, and a large current and a high voltage are applied, 78 is a diode bridge, a self-heating semiconductor such as an IGBT And a board to which a large current and a large voltage are applied to the inverter section on which the heat sink is mounted,
Reference numeral 79 denotes a control board including supply and release of a signal for switching at a frequency of 20 kHz or more.
0 indicates a length dimension of the substrate 79. 81 indicates the height of the substrate 78, 82 indicates the width of the substrate 77, and 83 indicates the height of the substrate 79. 84 is a dimension of the magnetron 61 including the board, 80 is a circuit wiring pattern in the board 77, 86 is a metal wiring that connects the board 77 and the board 78 electromechanically (metal as it is or a metal surrounding is covered with an insulating resin). 87 is a circuit wiring pattern in the substrate 78;
Reference numeral 88 denotes a metal wiring (including a metal as it is or a metal whose periphery is covered with an insulating resin) connecting the substrate 77 and the substrate 79, and 89 denotes a circuit wiring pattern in the substrate 79.

Reference numeral 90 denotes a holding jig for dipping the substrates 77, 78, and 79 at one time.

In FIG. 17, reference numeral 91 denotes an outer case metal on the top and side surfaces, 92 denotes a bottom surface, an outer case (metal or insulating resin) on the side surface, 93 denotes a highly insulating resin sheet, and 94 denotes an outer case on the bottom side surface. A high insulating sheet or resin, which is unnecessary when 32 is an insulating resin, but is required when metal is used, and 95 indicates a hole for ventilation.

In FIG. 18, reference numeral 96 denotes the vertical length of the exterior of the inverter and the magnetron unit, 97 denotes the height of the exterior, and 98 denotes the width.

In FIG. 19, reference numeral 99 denotes a control circuit.

In FIG. 20, 100 is a magnetron radiator fin, 101 is a magnetron core tube,
Reference numeral 102 denotes a magnetron heater terminal. 103 indicates a terminal of the high-voltage transformer, and arrow 104 indicates the flow of the wind.

In FIG. 21, reference numeral 93 shown by oblique lines indicates an insulating heat-resistant resin.

In the circuit board developed on the plane shown in FIG. 15, in this case, the three surfaces of the substrate are held on one plane by a holding jig 90, and the back surface (the surface opposite to the surface on which the After solder dip is performed on the surface where the terminals are exposed) and each component is connected to the circuit pattern electromechanically, without changing the size of the conventional component, Height dimension 81 of substrate 78
Is 60 mm, the width 82 of the substrate 77 is 66 mm,
9, the height 83 is 30 mm, the length of the substrate 79 is 80
Is 196 mm.

As shown in FIG. 16, by folding the board after component mounting to the component side excluding the chip component, the components can be accommodated in a smaller volume than a circuit having a planar configuration. This creates a space that creates a space, improves the flow of wind flowing by the fan, and improves heat dissipation. Then, an insulating sheet or insulating resin 93, 94 as shown in FIG. 17 is attached to the outer case metal 91, the outer case 92, or fixed by mechanical fitting or the like, and the outer case shown in FIG. It is fixed to the component circuit board 130 with screws or the like. As a result, the external shape of the integrated inverter and magnetron unit shown in FIG. 18 is obtained. The external housing metal 91 and the external housing 92 are made of a metal such as aluminum, and are fixed to the heat radiating plate 70 and heat radiating grease or a screw via a heat radiating sheet. By using the effect of the heat sink, higher heat dissipation can be secured. The width 98 of the board is 105 mm x (the size 97 in the side height direction is 70 m
In the case of (m + longitudinal width 96 is 70 mm), data showing the result of the IGBT temperature rising to 75 ° C. (difference from the ambient temperature) was obtained until the wind speed near the IGBT was 3 m / s. If not attached to the case, even if the wind speed is 6m / s or more,
The result that the temperature rose was obtained. In addition, when the conventional parts were incorporated without changing the dimensions, the external dimensions of the example were 70 mm for dimension 36 and 70 mm for dimension 37.
mm and the dimension 38 are 200 mm, and the volume ratio of the related art is 以下 or less only in the inverter section. The integrated inverter and magnetron unit is 1/5 or less as compared with a product that conventionally uses two motors.

FIG. 19 shows a typical example of an electric circuit of the inverter and magnetron integrated unit. Although this circuit does not include a circuit for operating the fan, a separate power supply is required depending on the type of the fan. In the case of an AC fan, it is necessary to supply a commercial power supply itself, and in the case of DC, a separate DC voltage needs to be supplied. In both cases of AC and DC, it is possible to introduce the DC voltage into an inverter circuit. The schematic operation will be described with reference to this circuit diagram.

A commercial power supply of AC 100 V to 240 V is rectified by a diode bridge 69 as an input, and
The power element (IGBT, etc.) 68 is switched by a signal of a frequency of several tens of kHz supplied from the drive circuit 71 via a driving circuit 71 to switch on and off a large current (up to a steady state within 15 A in Japan). , Condenser 7
3 and a resonance circuit of a coil on the primary side of the transformer 67, and an intermediate voltage (6 kHz) of a certain frequency (for example, 35 kHz).
(From 00V to 900V) to the primary side of the transformer. The secondary side of the transformer is boosted to a high voltage by the transformer 67 (steady minus 2,000 V, minus 350 at startup).
0 to 4000 V), a high voltage diode 64 and a high voltage capacitor 63 convert an alternating current into a direct current, and a double voltage rectified high voltage (minus 4000 V
When starting up, apply minus 7000-8000V)
The magnetron 61 is oscillated, and the magnetron 61
A high frequency of 450 MHz is generated.

FIGS. 20, 21, and 22 show cross sections of the integrated inverter and magnetron unit as shown in the external view of FIG. 18, showing an example of the arrangement of parts and the flow of wind flowing in the space therebetween. By having a three-dimensional structure, a space between the components is ensured, and in particular, direct heat is applied to the diode bridge 69 of the heat-generating semiconductor, the power element (IGBT or the like) and the high-voltage transformer (in the case of FIG. When a wind with a wind speed of 3 m / s or more hits (in this case, when the IGBT uses the exterior metal as the heat sink), the temperature rise of the power element can be suppressed to a temperature lower than the breaking temperature. The wind of the cooling fan 65 also hits the magnetron radiator, the magnetron core, the high-voltage condenser 63, and the high-voltage diode 64, and cools.
The magnetron 61 generates 400 W of heat, and reaches 100 ° C. from the exit of the magnetron 61. This air also helps to heat food by being introduced into a microwave oven (not shown), thereby conserving energy. A high voltage (2000 V or higher) terminal portion on the secondary side of the high voltage transformer 67, a high voltage diode 64 terminal, a high voltage capacitor 6
The three terminals, the magnetron heater terminal 102, the coil 62 terminal and the like are portions where a high voltage is particularly applied between the terminals and between the terminal and the ground.
2. The terminals such as the diode bridge 69, the power element 68, and the resistor receive a medium voltage (600 to 900 V) and a large current (steady 15 A or less in Japan). Therefore, the circuit board 7
7, 78 and 79 are lead frames 8 obtained by etching or pressing a copper plate having a thickness of about 0.3 to 0.5 mm.
5, 87, 89 are obtained by covering the substrates 77, 78, 79 with a highly insulating resin. As the insulating resin, PPS (polyphenylene sulfide), liquid crystal polymer, crystalline polystyrene, epoxy resin, dialphthalate, or the like that can withstand the high temperature of soldering is suitable.
As a covering method, injection molding or transfer molding in which a lead frame is placed in a mold and resin molding is performed, and hot press molding in which the lead frame is wrapped with a prepreg and heated and compressed and cured. Unlike a printed board that is pasted and etched on a conventional 0.035 mm paper-phenol board, the circuit boards 77, 78, and 79 can reduce the conductor pattern width and the conductor pattern interval, thereby saving space. Further, since the magnetron 61 is mounted on the circuit board 77, a high-voltage cable as in the conventional example is unnecessary, and the number of components can be reduced. In addition, by reducing the circuit configuration to a low power unit to which a large current and a high voltage are not applied and forming one or more substrates, the cost can be reduced by using a material such as paper phenol for the low power portion. Also, a high voltage (2000 V or more) terminal portion on the secondary side of the high voltage transformer 67, a high voltage diode 64 terminal, a high voltage capacitor 63 terminal, a magnetron heater terminal 102, a coil 6
The two terminals and the like are terminals such as a T-shaped protrusion of the high insulating resin substrate 77 and a support of the high voltage capacitor 63 of the high insulating resin 94 shown in FIG. The structure is such that a higher voltage can be endured by providing a concave portion and a support in the shape of the inverted inverted C shape.

FIG. 23 shows that the position of the fan 65 is between the inverter unit and the magnetron 61, and the heat radiating plate 70 (the attached heat generating plate) is used for radiating the self-heating semiconductor on the circuit board 140 having the three-dimensional circuit configuration. FIG. 2 is a cross-sectional view of an inverter and a magnetron integrated unit showing the shape of a unit (including components) and the positional relationship of the unit. The shape of a heat sink 70 is trapezoidal (there is also a hollow inside), and the wind direction of a fan 65 (X direction). On the other hand, by adopting a structure to be attached at a certain angle θ (range of 1 ° to 45 °), an effect of higher heat dissipation can be obtained. However, when reproducing the state in which the wind passes, the value of the optimum angle differs depending on the situation when the wind passes, depending on the size of the components, the mutual relationship between other components, and the like.

FIG. 24 shows that the position of the fan 65 is
5, the inverter and the magnetron 61 are arranged in this order, and the inverter and the magnetron are located at the leeward position, and the heat radiating plate 70 (mounted) is used for radiating the self-heating semiconductor on the circuit board 140 having the three-dimensional circuit configuration. FIG. 3 is a cross-sectional view of an inverter and a magnetron integrated unit showing the shape of a heat-generating component (including heat generating components) and the positional relationship of the units. With respect to the direction, the structure is attached at a certain angle (in the range of 1 ° to 45 °), so that an effect of higher heat dissipation can be obtained.

However, when reproducing the state in which the wind comes off,
The optimum value of the angle differs depending on the size of the component, the mutual relationship between other components, and the like, depending on the situation when the wind passes.

FIG. 25 is a longitudinal sectional view of the integrated unit of the inverter and the magnetron, and FIG. 26 is a sectional view taken along the line AA shown in FIG.

Referring to FIGS. 25 and 26, when the inverter, the magnetron integrated unit and the circuit board have only one surface which does not have a three-dimensional configuration, the wind supplied from the cooling fan 65 is applied to the core tube, magnet, and radiator of the magnetron 61. The air passage 111 corresponds only to a structure contributing to the cooling of the magnetron 61 such as a blade portion of the magnetron 61, and only the heater terminal 102 at the tube end where the effect of heat conducted from the magnetron tube below the magnetron 61 is small. A structure 113 having a certain thickness of a highly heat-insulating resin material is disposed in the space of the inverter section so as to be separated from the air passage 112, and the core tube of the magnetron 61, the magnets, and the radiator blades are provided. And wind passing through a structure that contributes to the cooling of the magnetron 61 In order to separate the wind passing through the heater terminal 102 at the end of the tube, which is less affected by the heat conducted from the magnetron tube at the lower part of the magnetron tube and the magnetron heating part, a heat insulating resin material having high heat insulation near the outlet is provided. An inverter having a structure 114 disposed therein,
The magnetron integrated unit has a function of high heat dissipation.

FIG. 28 is a longitudinal sectional view of an integrated unit of an inverter and a magnetron, and FIG.
2 is a top view of the inverter and magnetron integrated unit shown in FIG.

In FIGS. 27 and 28, the three-dimensional configuration of the inverter, the magnetron integrated unit, and the circuit board, and even in the case where only one surface does not have the three-dimensional configuration, the motor of the fan 65 is the motor 121, the fan A122 (blades), Inverter unit 123, fan B124 (blades),
The bearings 125 of the fan A122 are provided inside the motor, the bearings 126 of the fan B124 are provided near the fan B124, and the fans A122 and B124 are connected by a metal propeller shaft 127. A partition plate 128 made of a material such as heat-resistant resin having an inclination is provided on the rear side (fan B124 side) of the inverter unit, and a vent hole C129 for the wind coming from the fan A122 is provided on the outer peripheral portion. An inverter and a magnetron integrated unit having a structure in which the suction hole D140 of the fan B124 is installed near the hole C129 and on the outer peripheral side of the fan B124 with respect to the hole C129, thereby achieving high heat dissipation. Having.

[0060]

As described above, according to the present invention, space saving, reduction in the number of parts, reduction in wiring cables, high insulation,
Advantageous effects such as high heat dissipation, reduction in the number of assembly steps, and cost reduction can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an inverter and a magnetron integrated unit and a circuit board for mounting the integrated unit according to an embodiment of the present invention;

FIG. 2 is a plan view showing the inverter and magnetron integrated unit shown in FIG. 1 and a circuit board for mounting the unit.

FIG. 3 is a plan view of a lead frame constituting the circuit board;

FIG. 4 is a plan view showing a state in which a choke coil and a capacitor are formed by bending a lead frame.

FIG. 5 is a sectional view taken along line AA of FIG. 4 showing a configuration of a choke coil.

FIG. 6 is a sectional view taken along the line BB of FIG. 4 showing the configuration of the capacitor;

FIG. 7 is a cross-sectional view taken along the line CC of FIG. 4, showing a state where the end of the coil portion is bent.

FIG. 8 is a plan view of a lead frame for making a heat sink.

9 is a plan view showing a state in which the lead frame shown in FIG. 8 is bent and raised.

10 is a sectional view of the lead frame shown in FIG. 9 taken along the line DD.

FIG. 11 is a plan view of a lead frame for making another heat sink.

FIG. 12 is a plan view showing a state where the lead frame shown in FIG. 11 is bent and raised;

13 is a front view showing a state where the lead frame shown in FIG. 11 is bent and raised.

FIG. 14 is a plan view showing an integrated inverter and magnetron unit and a circuit board for mounting the integrated unit according to the second embodiment of the present invention;

FIG. 15 is an exploded perspective view showing an inverter, a magnetron integrated unit and a circuit board for mounting the integrated unit, according to a third embodiment of the present invention;

16 is a perspective view showing a state in which the mounting circuit board for mounting the integrated inverter and magnetron unit shown in FIG. 15 is bent to form a three-dimensional configuration.

17 is a perspective view showing a state where an external housing is combined with the mounting circuit board having the three-dimensional configuration shown in FIG. 16;

18 is a perspective view showing a state where the external housing shown in FIG. 17 is combined.

FIG. 19 is a circuit diagram of an integrated inverter and magnetron unit.

20 is a sectional view taken along the arrow A in the perspective view shown in FIG. 18;

FIG. 21 is a sectional view taken along the arrow B in the perspective view shown in FIG. 18;

FIG. 22 is a sectional view taken along the arrow C in the perspective view shown in FIG. 18;

FIG. 23 is a view showing the shape of a heat sink.

FIG. 24 is a view showing another shape of the heat sink.

FIG. 25 is a longitudinal sectional view of the inverter and the magnetron integrated unit in the longitudinal direction.

26 is a cross-sectional view of the integrated inverter and magnetron unit shown in FIG. 25 taken along the line AA.

FIG. 27 is a longitudinal sectional view of the inverter and magnetron integrated unit in the longitudinal direction.

FIG. 28 is a plan view of the inverter and magnetron integrated unit shown in FIG. 27;

FIG. 29 is a rear view of a conventional microwave oven main body.

FIG. 30 is a side view of a magnetron used in a conventional microwave oven.

FIG. 31 is a wiring diagram of the magnetron shown in FIG. 16;

FIG. 32 is a perspective view showing the structure of a conventional circuit board.

FIG. 33 is an elevation view of a heat sink used in a conventional power circuit.

[Explanation of symbols]

 19, 123, 141 Inverter 20 Axial fan 21, 61, 142 Magnetron 22 Circuit board 28 Lead frame 29 Resin 40 Choke coil 41 Capacitor 44 Electrode 45 Other electrode 46 Dielectric film 48 Heat sink 65 Cooling fan 70 Heat sink 91 Case metal 111, 112 Air path 113, 114 Structure of heat-resistant resin material 121 Motor part of fan 122 Fan A 124 Fan B 127 Propeller shaft 129 Air vent hole 130 Suction hole

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 6/64 H05B 6/64 A 5E338 41/24 41/24 N H05K 1/02 H05K 1/02 FL (72) Inventor Kazuho Sakamoto 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Matsushita Electric Industrial Co., Ltd., 1006 Kazuma, Kadoma, Fumonma-shi (72) Ryota Tobiyama 1-3-400 Umeda, Kita-ku, Osaka-shi, Osaka Excel Techno Co., Ltd. 1006 Kadoma Kadoma Matsushita Electric Industrial Co., Ltd. F term (reference) 3K072 AA17 AC11 BA03 BB09 CA16 FA05 GA01 GA07 GB01 3K090 AA04 AA15 AA20 EB16 EB23 EB25 EB40 3L086 AA01 BA10 BE11 DA17 DA23 DA30 5C029 AA01 JJ01 JJ02 JJ06 JJ07 NN04 5E082 BB02 EE23 5E338 AA05 AA16 BB51 BB58 BB75 CC04 CC08 CD07 CD22 EE02 EE12 EE31

Claims (20)

[Claims] An integrated magnetron unit comprising an inverter for oscillating a magnetron, a cooling fan, and a magnetron. 2. An inverter is provided upstream of the cooling fan, and a magnetron is provided downstream of the cooling fan.
The described inverter and magnetron integrated unit. 3. The inverter and magnetron integrated unit according to claim 1, wherein the magnetron is mounted on a circuit board of the inverter. 4. The circuit board according to claim 3, wherein a metal lead frame is covered with an insulating resin.
The described inverter and magnetron integrated unit. 5. The integrated inverter and magnetron unit according to claim 4, wherein a choke coil of a noise filter for preventing a radio wave returning from the magnetron to the inverter side is formed by cutting and raising a lead frame alternately. 6. A circuit board in which a metal lead frame is covered with an insulating resin, a part of the circuit pattern is widened to form an electrode, another electrode is opposed via a dielectric film, and the outside is made of a resin. The circuit board according to claim 4, wherein the capacitor is formed by molding. 7. The inverter according to claim 3, wherein the capacitor of the noise filter according to claim 5 for preventing radio waves returning from the magnetron to the inverter side is a capacitor built in the circuit board according to claim 6. Magnetron integrated unit. 8. A circuit board formed by resin molding so as to cover a metal lead frame with an insulating resin, wherein a part of the circuit pattern is expanded, and the expanded portion is bent and raised to form a heat sink. The circuit board according to claim 3. 9. The circuit board according to claim 8, wherein a metal lead frame near the component to be mounted is bent and raised. 10. The circuit board according to claim 8, wherein a metal lead frame below a component to be mounted is bent up. 11. An inverter and a magnetron integrated unit in which an inverter power supply for oscillating a magnetron, a cooling fan, and a magnetron are integrated.
A circuit board that divides the circuit components constituting the inverter power supply into blocks, and has a divided mounting circuit board in which the circuit components are mounted and wired on a wiring pattern; And a wiring pattern of a conductive material for mechanically and electrically connecting and joining the divided mounting circuit boards, wherein the mounting circuit board has Is bent vertically in a linear direction so that a component having a certain size on the inner surface comes to have a structure having a three-dimensional configuration, the cooling fan, an inverter, and a magnetron are arranged in this order, the mounting circuit board having the three-dimensional configuration, and Inverter and magnetron having a configuration in which an exterior plate is provided around a cooling fan and the inverter and the magnetron are arranged downwind of the cooling fan. Body unit. 12. An inverter, a cooling fan, and a magnetron are arranged in this order, and the inverter is located on the windward side.
12. The integrated inverter and magnetron unit according to claim 11, wherein the magnetron is arranged leeward. 13. A heat radiating plate to which a self-heating semiconductor of an inverter section is fixed is provided on a part of a metal casing of the exterior of the unit through a radiating grease or a radiating sheet, or an insulating plating such as alumite on the metal casing. Claim 1 attached
13. The inverter and magnetron integrated unit according to 1 and 12. 14. The integrated inverter and magnetron unit according to claim 11, wherein the mounting circuit board having a three-dimensional configuration has a configuration in which a metal lead frame is covered with an insulating resin. 15. The integrated inverter and magnetron unit according to claim 14, wherein a part of the inverter circuit and the magnetron are mounted on the same circuit board in which a metal lead frame is covered with an insulating resin. 16. A part of a circuit board having a three-dimensional configuration is formed of a phenol resin copper-clad laminated board or a glass epoxy copper-clad laminated board, and the connection between the circuit boards is performed by soldering lead wires or through a connector. 16. The integrated inverter and magnetron unit according to claim 11, 12, 13, 13, or 15, wherein the connection is made by electromechanical connection by wire connection or soldering of a plated metal wire. 17. The integrated inverter and magnetron unit according to claim 11, wherein the heat radiating plate of the self-heating semiconductor is attached with an inclination with respect to the wind direction of the cooling fan. 18. In an inverter and magnetron integrated unit in which an inverter power supply for oscillating a magnetron, a cooling fan and a magnetron are integrated on a circuit board in the same plane, wind supplied from the cooling fan is
Insulation that separates the airflow into the structure that contributes to the cooling of the magnetron, and the airflow that falls only on the heater terminal at the tube end where the effect of heat conducted from the magnetron tube below the magnetron is small. Place the heat-resistant resin material structure in the space of the inverter section,
An inverter and magnetron integrated with a heat-insulating heat-resistant resin structure located near the outlet that separates the wind that has passed through the structure contributing to the cooling of the magnetron and the wind that has passed through the inverter heating section and the heater terminal section below the magnetron unit. 19. A motor unit of a cooling fan, a fan A,
An inverter unit, a fan B, and a magnetron are arranged in this order, the bearing of the fan A is installed inside the motor, the bearing of the fan B is provided near the fan B, and the fans A and B are made of metal. 19. The integrated inverter and magnetron unit according to claim 18, wherein the unit is connected by a propeller shaft. 20. An inclined heat-resistant resin partition plate is provided on the fan B side of the inverter unit, and a vent hole C for wind coming from the fan A is provided on an outer peripheral portion.
20. The integrated inverter and magnetron unit according to claim 19, wherein a suction hole D of the fan B is provided at an outer peripheral portion of the fan B side from the hole C.