JPH11163490A - Electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device having a simple structure and which can be manufactured at low cost, without thermal nonconformities from an exothermic element. SOLUTION: A circuit constituted of an exothermic element 25 and the like in a control unit is assembled on a metallic sub-board 1, while a circuit made up of a low exothermic element 11 and the like in the control unit is assembled on a main resin board 9. The main resin board 9 has a through-hole space 17 for inserting the metallic sub-board 1. A flexible electrically connecting means 3 for connecting the sub-board 1 and the main board 9 is provided. The low exothermic element 11 and the like are solder mounted on the main board 9, while the exothermic element 25 and the like are mounted on the sub-board by soldering. The circuit of the main board 9 and the circuit of the sub-board 1 are connected through the flexible electrically connecting means 3. In this way, the manufacturing cost is reduced, and an additional connecting part for the exothermic element 25 and the like can be omitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a main board provided with electronic elements generating little heat, such as a control small-power circuit, and a sub-board provided with electronic elements generating much heat, such as a large-power circuit. The present invention relates to an electronic device constituted by:

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a front view showing a conventional electronic device disclosed in Japanese Patent Application Laid-Open Publication No. H10-15095.
In the figure, 1 is a sub-substrate made of a metal plate, 2 is a sub-substrate 1
Layer 3, an aluminum base plate fixed to the lower surface of the insulating layer 2, 4 cooling fins fixed to the lower surface of the base plate 3, and 5 fixed to the upper surface of the sub-substrate 1. A conductor pattern forming a circuit, 6 is a pad, and 7 is a solder.

Reference numeral 8 denotes a heat-generating element composed of electronic components mounted on the sub-board 1, and includes a resistor, a diode, and a power MOSFET.
T or the like. Reference numeral 9 denotes a main board made of a synthetic resin plate, 10 denotes a transformer provided on the main board 9 and forms a first low heat-generating element that forms a circuit of the main board 9, and 11 denotes an IC formed by an IC mounted on the main board 9. This is a second low heat generation element that forms a circuit of the substrate 9.

[0004] Reference numeral 12 denotes a third low heat-generating element which is composed of various capacitors mounted on the main substrate 9 and forms a circuit of the main substrate 9, and comprises a tantalum capacitor, a ceramic capacitor, an electrolytic capacitor and the like. Reference numeral 13 denotes a terminal block mounted on the main substrate 9, and reference numeral 14 denotes a support fixed to the lower side of the main substrate 9, and the cooling fins 4 are fixed to the ends. Fifteen
Is a land, and 16 is an aluminum wire for electrically connecting the circuits of the sub-board 1 and the main board 9.

FIG. 10 shows, for example, Japanese Patent Application Laid-Open No. 4-9248.
FIG. 9 is a plan view showing another conventional electronic device disclosed in Japanese Patent Publication No. 7-No. In the figure, the same reference numerals as those in FIG. 9 described above denote corresponding parts, and reference numeral 17 denotes a through space provided in the main substrate 9,
Are arranged in a fitted state. Reference numeral 18 denotes an electric wiring connecting the heat-generating elements 8 provided on the sub-board 1 and the main board 9.

FIG. 11 is a front view showing another conventional electronic device in which a power module is mounted on a substrate. In the figure, the same reference numerals as those in FIG.
Is a small signal diode mounted on the main substrate 9, 20 is a resistor mounted on the main substrate 9, 21 is a small signal transistor mounted on the main substrate 9, 22 is a diode stack, and 23 is a transistor module.

Reference numeral 24 denotes a connection pin, which is a diode stack 2
2. Transistor module 23 is connected to land 1 of main substrate 9
5 parts are connected by solder 7. The main substrate 9 includes a third low heat generating element 12, a small signal diode 21, a resistor 2
2, the second low heat generating element 11, the small signal transistor 21,
Electronic components such as a terminal block 13 are mounted on the lands 15 with solder 7.

A conventional electronic device is configured as described above,
In the electronic device shown in FIG. 9, the exothermic element 8 provided on the sub-board 1 is connected to the pad 6 by the solder 7. Then, a circuit is formed by the conductor pattern 5, and a required function is achieved. Further, the first low heat generating element 10, the second low heat generating element 11, the third low heat generating element 12, and the terminal block 13 arranged on the main substrate 9 are connected to the pads 6 and the lands 15 by solder 7. Then, a circuit is formed by the conductor pattern 5, and a required function is achieved.

The transmission and reception of signals and power between the sub-board 1 and the main board 9 are performed by the aluminum wires 16. In such a configuration, since the sub-substrate 1 is provided with the heat-generating element 8 that generates a large amount of heat, the base plate 3 made of aluminum is provided so that heat can be easily transmitted to the cooling fins 4.

Then, the cooling fins 4 radiate heat to the surrounding air to suppress a rise in temperature, thereby preventing the heat generating element 8 from overheating. Further, the first low heat generating element 10, the second low heat generating element 11, the third low heat generating element 12, and the terminal block 13 mounted on the main board 9 are thermally isolated from the sub board 1 and the cooling fins 4. It is mounted on the support 14 and is maintained at a temperature close to room temperature.

Further, in the electronic device shown in FIG. 10, the sub-substrate 1 is disposed in the through-hole 17 of the main substrate 9 in a fitted state and is integrally provided with the sub-substrate 1 and the main substrate 9.
Is printed with the conductor pattern 5. The high-voltage portion of the conductor pattern 5 is printed on the sub-substrate 1 and the heating element 8 is provided. The first low-heating element 10 and the second low-heating element are printed on the conductor pattern 5 printed on the main board 9. 11, a third low heat generating element 12 and a terminal block 13 are provided to protect the first low heat generating element 10 and the like from heat generation of the sub-board 1.

[0012]

In the conventional electronic device as described above, after the first low heat generating element 10 and the like are mounted on the main board 9 by the solder 7, the heat generating element 8 of the sub-board 1 is mounted.
Are connected to the main substrate 9 with solder 7. For this reason, there is a problem that the manufacturing cost is increased, and materials for connection terminals and packages related to the heat-generating element 8 are expensive. There was a problem.

Further, since both the sub-board 1 and the main board 9 are mounted on a structure such as the cooling fins 4, the respective boards connected to the aluminum wires 16 and the cooling fins at the time of replacement of the board during maintenance or the like. The substrate is replaced by separating the structure such as 4 from the structure. Therefore, it is troublesome, and each board connected by a thin wire such as the aluminum wire 16 is handled as a maintenance part.
There has been a problem that the connection portion is easily peeled and the reliability as a maintenance part is impaired.

In a configuration in which the two are connected by a metal piece, a connector, or the like, the two can be easily separated from each other, but the production cost increases due to the cost of parts such as the connector and the time required for mounting. Further, the sub-board 1 is fitted into the through space 17 of the main board 9, and thereafter the conductor pattern 5
Is printed. Therefore, when the electric wiring of the sub-board 1 is changed, a plate for printing the conductor pattern 5 including both of them is manufactured, which increases the cost.

Further, the distance between the wirings of the high-voltage circuit portion of the conductor pattern 5 needs to be increased in proportion to the voltage difference in order to secure insulation, and the area of the expensive sub-substrate 1 increases. Costs will increase. Furthermore, when the current-carrying part such as the first low heat-generating element 10 and the soldered part contacts the cooling fins 4 on the main board 9, a short circuit occurs in the electric circuit and damage occurs. When the main substrate 9 is disposed close to the cooling fins 4, the heat of the cooling fins 4 causes deterioration of the main substrate 9 and changes in characteristics of the mounted first low heat-generating element 10 and the like. There has been a problem that reliability is reduced.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide an electronic device which has a simple configuration and does not have a thermal problem relating to a heat generating element.

[0017]

An electronic device according to the present invention comprises a sub-substrate provided with a circuit formed by a heat-generating element made of a metal plate and constituting a part of the control device, and a resin plate. A main board provided with a circuit formed by a low heat-generating element constituting the other part of the control device, and a through-hole provided, and a sub-board arranged in a fitted state in the through-hole; And flexible electrical connection means for connecting the circuits of the main board.

Further, in the electronic device according to the present invention, there is provided a mounting frame in which the sub-substrate is fitted on the inner periphery and the outer periphery is fitted in a through space of the main substrate.

Further, in the electronic device according to the present invention, an insulating frame provided on the main substrate in an upright state and surrounding the sub-substrate and the flexible electric connection means; And a filler that has electrical insulation performance and seals electrical components disposed in the insulating frame body.

Further, in the electronic device according to the present invention, the electronic device is provided on the main substrate in an upright state, and is disposed so as to surround the sub-substrate, the flexible electrical connection means, and the high-voltage circuit portion mounted on the main substrate. And a filler filled in the insulating frame and sealing the electrical components disposed in the insulating frame and having electrical insulation performance.

In the electronic device according to the present invention, a filler made of a transparent material is provided.

In the electronic device according to the present invention, an insulating sheet made of an electrically insulating material is provided between the cooling fin provided on the sub-substrate and facing the main substrate and the main substrate. Can be

In the electronic device according to the present invention, the cooling fin is made of a material that does not deform or degrade in performance with respect to the temperature of the cooling fin. A heat-resistant sheet is provided between the heat-resistant sheet and the substrate.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 1 to 8 show an embodiment of the present invention. FIG. 1 is a vertical sectional front view of an electronic device, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a plan view of a mounting frame of FIG. 4 is a sectional view taken along line AA of FIG. 3, and FIG.
6 is a circuit diagram of the inverter device of the electronic device in FIG. 6, FIG. 6 is a circuit diagram of the high-voltage circuit unit in FIG. 1, and FIG. 7 is a manufacturing process diagram of the electronic device in FIG.

In the drawing, 1 is a sub-substrate made of a metal plate,
2 is an insulating layer fixed to the lower surface of the sub-substrate 1 and 3 is an insulating layer 2
An aluminum base plate fixed to the lower surface of the base plate, 24 is an insulating sheet in which the base plate 3 is fitted into the opening and the lower surface is arranged on the same surface as the lower surface of the base plate 3, and 4 is fixed to the lower surface of the base plate 3. The cooling fins 5 are conductor patterns fixed to the upper surface of the sub-substrate 1 to form a circuit, 6 is pads, 7 is solder, and 15 is a land.

Reference numeral 25 denotes a first heat-generating element composed of a power transistor mounted on the sub-substrate 1, and 26 denotes a second heat-generating element composed of a power diode mounted on the sub-substrate 1. It is provided via a pattern 5 and a pad 6 and is equipped with solder 7. As the first heat generating element 25, a MOSFET, an IGBT, a bipolar transistor or the like is used. Note that the first heat generating element 25 and the second heat generating element 26 may be replaced with other appropriate chip elements and electronic components for surface equipment.

9 is a main board made of a synthetic resin plate, 12 is a third low heat-generating element made of various capacitors mounted on the main board 9, 19 is a small signal diode mounted on the main board 9, and 20 is a main board. A resistor mounted on the substrate 9, 11 is a second low heat-generating element composed of an IC, 21 is a small signal transistor mounted on the main substrate 9, 13 is a terminal block, and 17 is a through space provided on the main substrate 9. It is.

Then, the third low heat generating element 1 is provided on the main substrate 9.
2. Electronic components such as a small signal diode 19, a resistor 20, a second low heat generating element 11, a small signal transistor 21, and a terminal block 13 are mounted on the land 15 by soldering 7. The main substrate 9 is made of a laminate using paper, glass, alumina, or the like as a base material, and using epoxy, phenol, or the like as a resin.

Reference numeral 27 denotes a mounting frame made of an insulating material such as a resin. A bar having a Z-shaped cross section is assembled in a rectangular shape. The outside of the Z-shaped vertical part is fitted into the through space 17. The sub-board 1 and the base plate 3 are fitted inside the Z-shaped vertical part. Reference numeral 28 denotes a fastening screw that is inserted from the upper surface of the main board 9 into the main board 9, the flange portion of the mounting frame 27, and the insulating sheet 24 and screwed into the cooling fin 4. In addition, the through space 17 of the main substrate 9
When the sub-board 1 is directly fixed to the sub-board 1 with an insulating adhesive or the like, the mounting frame 27 is unnecessary.

The insulating sheet 24 is provided to ensure electrical insulation between the cooling fins 4 and current-carrying parts such as the lands 15 of the conductor pattern 5 of the main substrate 9. Thereby, damage due to a short circuit in the electric circuit of the main board 9 can be prevented. Further, since the main substrate 9 is protected against the heat of the cooling fins 4 by the insulating sheet 24, it is possible to prevent deterioration of the main substrate 9 and a decrease in reliability due to a change in characteristics of electronic components mounted on the main substrate 9. it can.

The insulating sheet 24 is made of a material that does not deform or deteriorate in performance with respect to the temperature of the cooling fins 4. The area of the insulating sheet 24 is set to a size corresponding to the facing surface between the main substrate 9 and the cooling fins 4. Therefore, when the area of the cooling fin 4 facing the main substrate 9 is small, the size of the cooling fin 4 can be reduced in accordance with the area of the cooling fin 4.

When it is not necessary to electrically insulate the cooling fins 4 from the current-carrying parts such as the lands 15 of the conductor pattern 5 of the main substrate 9, a heat-resistant sheet for heat insulation is used instead of the insulating sheet 24. Is provided, heat conduction from the cooling fins 4 to the main substrate 9 can be reduced. In addition, the insulating sheet 2
There is no problem even if both 4 and heat-resistant sheet are equipped.

Reference numeral 29 denotes an insulating frame, which is mounted on the upper surface of the main substrate 9 in an upright state and is arranged so as to surround the sub-substrate 1 and the pads 6 of the main substrate 9, that is, flexible electric connection means described later. I have. Reference numeral 30 denotes a filler having electrical insulation performance, which is disposed in the insulating frame 29 in a filled state, and seals electric components in the insulating frame 29. Numeral 31 denotes a flexible electrical connection means made of wire bonding, which is made of aluminum wire for electrically connecting the circuit of the sub-substrate 1 and the main substrate 9 with the filler 3.
It is arranged in a buried state during the period 0.

Note that the insulating frame body 29 is
It is fixed with an insulating adhesive or a highly viscous resin, or is fitted in the main substrate 9 with a fitting groove. Further, as the filler 30, a substance having a dielectric breakdown voltage performance, such as a silicon resin, is selected. In addition, it is necessary that the filler 30 be closely adhered to the fixing portion between the insulating frame body 29 and the main substrate 9 so that the filler 30 does not leak from the gap.

For this reason, as a measure for preventing the generation of a gap, a multilayer board is used for the main board 9 so that the conductor pattern 5 does not intersect with the fixing portion between the insulating frame 29 and the main board 9 so that the overlapping portion is formed. , The generation of a gap can be eliminated. Although the insulating frame 29 is mounted on the main substrate 9, the effect described later can be obtained even if the insulating frame 29 is mounted on the sub-substrate 1.

It is to be noted that, by making at least the material of the filler 30 out of the insulating frame 29 and the filler 30 transparent, the insulating frame 29 is manufactured after the electronic device is manufactured.
It is possible to easily detect the installation state of the electronic components inside and the connection state of the flexible electric connection means 31. As a result, manufacturing management can be facilitated.

32 is an AC power supply, 33 is a rectifier circuit, 34 is a smoothing circuit connected to the output of the rectifier circuit 33, 35 is an inverter circuit connected to the output of the smoothing circuit 34, and 36 is connected to the output of the inverter circuit 35. Motor, 37 is an inverter drive circuit, 38 is an inverter signal generation circuit, 3
9 is an operation command signal.

The sub-substrate 1 is provided with the second exothermic element 26 constituting the rectifier circuit 33 and the first exothermic element 25 constituting the inverter circuit 35. The sub-substrate 1 may be provided with a heat-generating element such as a transistor for a switching power supply or the like, which is made up of an electronic component generating a large amount of heat.

FIG. 6 is a circuit diagram showing one phase of the inverter circuit 35 and the inverter drive circuit 37. That is, the first power transistor 40 and the second power transistor 41 connected in series are connected to the high voltage part P of the smoothing circuit 34.
And the low pressure section N. 42 is a first inverter driving circuit for driving connected to the first power transistor 40, 43 is a second inverter driving circuit for driving connected to the second power transistor 41, and 44 is a first inverter driving circuit 42 Is a PWM first signal, and 45 is a PWM second signal input to the second inverter drive circuit 43.

In the electronic device configured as described above, the output of the AC power supply 32 is converted to DC by the rectifier circuit 33, and is smoothed by the smoothing circuit 34 to a DC voltage with less pulsating flow. Then, when the operation command signal 39 is input to the inverter signal generation circuit 38, an inverter drive signal is generated and input to the inverter drive circuit 37. Thereby, the power semiconductor of the inverter circuit 35 operates to obtain an alternating current of a required frequency and voltage. Then, the connected electric motor 36 is driven by the output of the inverter circuit 35.

When the power semiconductor of the inverter circuit 35 operates, the first heat-generating element 25 composed of a power transistor and the second heat-generating element 26 composed of a power diode are provided on the sub substrate 1 having good thermal conductivity. Therefore, the heat of these heat generating elements is transmitted to the cooling fins 4.

As a result, the heat of the heat-generating element is radiated around the cooling fins 4 to cool the first heat-generating element 25 and the like. Accordingly, the third low heat generating element 12 and the like provided on the main substrate 9 are protected from the heat generated by the sub-substrate 1, and the performance of the main substrate 9 itself and the mounted elements such as the third low heat generating element 12 are deteriorated and deteriorated. Changes in characteristics are suppressed, and the reliability of the electronic device can be maintained.

Next, a manufacturing process of the above-described electronic device will be described with reference to FIG. That is, the solder 7 is applied to the sub-substrate 1 in step / 01, and an electronic element such as the first heat-generating element 25 including a power transistor is mounted in step / 02. Next, reflow soldering for heating the sub-board 1 to harden the solder 7 is performed in step / 03, and the sub-board 1 is fitted to the mounting frame 27 in step / 04.

In parallel with the operation of the sub-substrate 1 on the main substrate 9, an automatic insertion machine (not shown) and an electronic element such as a third low heat-generating element 12 composed of a capacitor are manually mounted in step 05. You. Next, the land 15 is passed through a solder bath (not shown) in step / 06.
Flow soldering is performed to attach the solder 7 to the substrate. Then, in step / 07, the sub-board 1 is fitted into the through space 17 via the mounting frame 27, and the sub-board 1 is fixed to the main board 9 in the state shown in FIG.

Then, in step 08, the circuit of the sub-board 1 and the circuit of the main board 9 are electrically connected by the flexible electric connection means 31 made of aluminum wire. Then, the process proceeds to step 09, where the insulating frame 2 is placed at a predetermined position on the main substrate 9.
9 is attached. Next, in step / 10, the filler 30 is injected into the insulating frame 29, and the flexible electric connection means 31 and the like are disposed and sealed in the filler 30, and the process proceeds to step / 11 where the filler 30 is heated. Is cured.

The filler 30 can be heated without loss to the electronic element by using thermosetting silicon which is cured at 70 ° C. for 30 minutes. Step / 01 to step / 04 and step / 0
Regarding step 5 and step / 06, either a parallel operation or a serial operation can be appropriately selected and implemented.

As described above, in the embodiment shown in FIGS. 1 to 7, after the first low heat generating element 10 and the like are mounted on the main substrate 9 shown in FIG. The connection terminal relating to the conductive element 8 is not soldered to the main substrate 9. Then, the circuits of the sub-board 1 and the main board 9 are connected to each other by the flexible electric connection means 31. Therefore, manufacturing costs can be reduced. Further, the materials for the connection terminals, the package, and the like relating to the heat-generating element 8 are expensive, and the proportion of the cost of the heat-generating element 8 as a whole increases. However, since these elements are not required, an increase in cost can be suppressed.

Further, since both the sub-board 1 and the main board 9 are not attached to each other via the structure such as the cooling fins 4, the respective boards are replaced by the cooling fins 4 or the like at the time of replacement of the board at the time of maintenance or the like. There is no need to separate for structures. Therefore, the substrate can be replaced without complicated work.

Further, the sub-board 1 is mounted in the through space 17 of the main board 9 via the mounting frame 27, and the sub-board 1 is integrated with the main board 9 with high rigidity. For this reason, the respective boards connected by thin wires such as the aluminum wires 16 in FIG. 9 described above are not treated as maintenance parts.

Therefore, it is possible to solve the problem that the disconnection of the aluminum wire 16 and the peeling of the connection portion are apt to occur, and the reliability as a maintenance part is impaired. Further, since the sub-board 1 is mounted on the main board 9 via the mounting frame 27, handling is easy, and the sub-board 1 can be easily mounted at a predetermined position, thereby reducing obstacles to automatic assembly work. can do. Further, the creepage distance between the wiring portion of the sub-board 1 and the main substrate 9 and between the wiring portions of the high-voltage circuit can be secured by the arrangement of the mounting frame 27.

Therefore, even when the wiring is arranged up to the peripheral portions of the sub-substrate 1 and the main substrate 9, required insulation can be easily secured. In a configuration in which both the sub-board 1 and the main board 9 are connected by a metal piece, a connector, or the like, the two can be easily separated from each other, but the manufacturing cost increases. Means 3
1 connected. Therefore, manufacturing costs can be reduced.

Further, the conductor pattern 5 is printed on each of the two. Therefore, when one of the two electric wirings is changed, it is possible to manufacture a printing plate for printing the conductor pattern 5 of only one of the two electric wirings. Therefore, it is possible to reduce the cost for changing the electric wiring.

Further, since the insulating sheet 24 is disposed at the portion where the cooling fins 4 and the main board 9 are opposed to each other, the current-carrying parts such as the third low heat-generating element 12 and the solder 7 on the main board 9 are cooled. There is no contact with the fins 4 and there is no risk of damage due to short circuit of the electric circuit. Further, when the main substrate 9 is arranged close to the cooling fins 4, the heat of the cooling fins 4 may cause deterioration of the main substrate 9 and change in characteristics of the first low heat generating element 10 and the like provided. Since the occurrence of such a problem is suppressed by the insulating sheet 24, the reliability of the electronic device can be improved.

Since the electric parts such as the flexible electric connection means 31 are sealed with the filler 30 by providing the insulating frame 29, the insulation deterioration due to moisture absorption when dust adheres to the electric parts and the vibration caused by vibrations. The load due to external force on the flexible electrical connection means 31 and the like can be reduced. Furthermore, insulation can be ensured even if the distance between the conductor patterns 5 in the wiring of the high voltage circuit is reduced. Therefore,
The mounting area of the high-voltage circuit can be reduced, and the manufacturing cost can be reduced.

In the embodiment shown in FIGS. 1 to 7,
Although the flexible electric connection means 31 has been described as being made of an aluminum wire, the same operation as in the embodiment of FIGS. 1 to 7 can be obtained even if the flexible electric connection means 31 is made of an appropriate wire such as a gold wire. . Further, the circuit of the sub-board 1 and the main board 9 has been described as including the inverter circuit 35. However, the circuit formed by the sub-board 1 and the main board 9 forms an air conditioner,
Even in a circuit of an electronic device such as a fluorescent lamp, the same operation as in the embodiment of FIGS. 1 to 7 can be obtained.

Embodiment 2 The electronic device can be easily configured as described below by applying the embodiment of FIGS. That is, the insulating sheet 24 provided for ensuring electrical insulation between the current-carrying portion such as the conductor pattern 5 of the main substrate 9 and the cooling fins 4 is deformed with respect to the temperature of the cooling fins 4 and performance is deteriorated. Replace it with a heat-resistant sheet without any.

As a result, the cooling fin 4 is moved from the main substrate 9
The heat conduction to the heat can be reduced. Since the main substrate 9 is protected against the heat of the cooling fins 4, it is possible to prevent deterioration of the main substrate 9 and a decrease in reliability due to a change in characteristics of electronic components mounted on the main substrate 9.

Embodiment 3 FIG. FIG. 8 is a plan view of an electronic device showing an example of another embodiment of the present invention. In addition,
Except for FIG. 8, the electronic device is configured in the same manner as the above-described embodiment of FIGS. In the drawings, the same reference numerals as those in FIGS. 1 to 7 denote corresponding parts, 46 is a high-voltage circuit portion mounted on the main substrate 9, 29 is provided on the sub-substrate 1, It is arranged so as to surround 31 places and the high voltage circuit section 46 mounted on the main board 9.

In the electronic device, the first inverter drive circuit 42 and the second inverter drive circuit 43 have a high voltage circuit section 46 different from a low voltage circuit such as the second low heat generating element 11 formed of an IC such as a microcomputer. I do. The high voltage circuit section 46 requires a long creepage distance between the conductor patterns 5 in order to ensure insulation performance.

However, in the electronic device configured as described above, it is surrounded by the insulating frame 29 including the high-voltage circuit section 46 together with the electronic elements such as the first heat-generating element 25 composed of a power transistor, and is higher than air. A high voltage circuit part 4 is filled with a filler 30 such as silicon resin having a dielectric breakdown voltage performance.
6 and the like are sealed.

Thus, the required insulation performance can be ensured even if the creepage distance between the conductor patterns 5 in the high-voltage circuit section 46 is equal to that of the low-voltage circuit. Therefore, it is not necessary to increase the distance between the wirings of the high-voltage circuit portion of the conductor pattern 5 in proportion to the voltage difference in order to ensure insulation, and it is possible to eliminate an increase in the area of the expensive sub-board 1 and reduce costs. Can be.

[0062]

As described above, the present invention relates to a sub-substrate provided with a circuit formed by heat-generating elements made of a metal plate and constituting a part of the control device, and a sub-board made of a resin plate and other components. A main board provided with a circuit formed by the low heat-generating elements constituting the part, and a through-hole is provided, and the sub-board is arranged in this through-hole in a fitted state; Flexible electrical connection means for connecting the circuits to each other.

This eliminates the need to solder the connection terminals relating to the heat-generating elements of the sub-board to the main board after the low heat-generating elements are mounted on the main board by soldering. Are connected by flexible electrical connection means. For this reason, the manufacturing cost can be reduced, and the materials for the connection terminals and the package related to the heat-generating element are expensive, which makes up a large proportion of the total cost of the heat-generating element. Has the effect of suppressing the rise of

Further, as described above, the present invention provides a mounting frame in which the sub-board is fitted on the inner periphery and the outer periphery is fitted in a through space of the main board.

As a result, the sub-board is mounted at a predetermined position in the through space of the main board via the mounting frame, and the sub-board is integrated with the main board with high rigidity. For this reason, the main board and the sub-board can be handled in a stable state without relative displacement, and there is an effect of preventing a decrease in quality and facilitating an automatic assembly operation.

Further, as described above, the present invention provides an insulating frame provided on a main substrate in an upright state and surrounding a sub-substrate and a flexible electrical connection means, And a filler having electrical insulation performance that seals the electrical components placed in the insulating frame body.

As described above, since the insulating frame is provided and the electric components such as the flexible electric connection means are sealed by the filler,
This has the effect of alleviating insulation degradation due to moisture absorption when dust adheres to the electrical components, and reducing the load on the flexible electrical connection means due to vibration. Furthermore, even if the distance between the conductor patterns in the wiring of the high-voltage circuit is shortened, insulation can be secured, the mounting area of the high-voltage circuit can be reduced, and the production cost can be reduced.

Further, as described above, the present invention is provided on the main board in an upright state, and is disposed so as to surround the sub-board, the flexible electrical connection means, and the high voltage circuit section mounted on the main board. And a filler filled in the insulating frame and sealing the electric components arranged in the insulating frame and having electrical insulating performance.

As described above, the electric parts such as the flexible electric connection means are sealed with the filler by providing the insulating frame.
This has the effect of alleviating insulation degradation due to moisture absorption when dust adheres to the electrical components, and reducing the load on the flexible electrical connection means due to vibration. Furthermore, even if the distance between the conductor patterns in the wiring of the high-voltage circuit is reduced, insulation can be secured, the mounting area of the high-voltage circuit can be reduced, and the production cost can be reduced. In addition, even if the creepage distance between the conductor patterns in the high-voltage circuit portion is equivalent to that of the low-voltage circuit, the required insulation performance can be ensured, and there is no need to increase the distance between the wirings in the high-voltage circuit portion of the conductor pattern. This has the effect of eliminating the increase and reducing the cost.

Further, as described above, the present invention is provided with a filler made of a transparent substance.

After the manufacture of the electronic device, the interior of the filler can be seen, and the state of the internal electronic components,
The connection state and the like of the flexible electric connection means can be easily detected. This has the effect of facilitating manufacturing control and improving quality.

Further, as described above, according to the present invention, an insulating sheet made of an electrically insulating material is provided between a cooling fin provided on a sub-substrate and facing a main substrate and a main substrate. It is a thing.

As a result, it is possible to ensure electrical insulation between the current-carrying portion such as the land portion of the conductor pattern of the main board and the cooling fin. And there is an effect of preventing damage due to short circuit in the electric circuit of the main board. Further, since the main board is protected against the heat of the cooling fins by the insulating sheet, there is an effect of preventing deterioration of the main board and a decrease in reliability due to a change in characteristics of electronic components mounted on the main board.

Further, as described above, the present invention comprises a cooling fin which is formed of a material which does not deform or deteriorate in performance with respect to the temperature of the cooling fin and which is provided on the sub-substrate and is arranged to face the main substrate. A heat-resistant sheet is provided between the substrate and the substrate.

Thus, heat conduction from the cooling fins to the main substrate can be reduced. Further, since the main substrate is protected against the heat of the cooling fins, there is an effect of preventing deterioration of the main substrate and a decrease in reliability due to a change in characteristics of electronic components mounted on the main substrate.

[Brief description of the drawings]

FIG. 1 is a view showing Embodiment 1 of the present invention, and is a longitudinal sectional front view of an electronic device.

FIG. 2 is a plan view of FIG.

FIG. 3 is a plan view of the mounting frame of FIG. 2;

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a circuit diagram of an inverter device of the electronic device in FIG. 1;

FIG. 6 is a circuit diagram of a high-voltage circuit unit in FIG. 1;

FIG. 7 is a manufacturing process diagram of the electronic device in FIG. 1;

FIG. 8 shows the second embodiment of the present invention, and is a plan view of an electronic device.

FIG. 9 is a front view showing a conventional electronic device.

FIG. 10 is a plan view showing another conventional electronic device.

FIG. 11 is a front view showing another conventional electronic device in which a power module is mounted on a substrate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Sub-substrate, 4 cooling fins, 9 main substrate, 11 second low heat generating element, 12 third low heat generating element, 17 through space, 24 insulating sheet, 25 first heat generating element, 26
Second heat generating element, 27 mounting frame, 29 insulating frame, 30
Filler, 31 flexible electrical connection means, 46 high voltage circuit.

Claims (7)

[Claims] 1. A sub-substrate provided with a circuit formed by a heat-generating element made of a metal plate and constituting a part of a control device, and a low heat-generating element made of a resin plate and constituting another part of the control device The circuit formed by the above is provided, and a through-hole is provided, and a main board in which the sub-board is arranged in a fitted state in the through-hole and a circuit between the sub-board and the main board can be connected to each other. An electronic device comprising: a flexible electric connection means. 2. The electronic device according to claim 1, further comprising a mounting frame having an inner periphery fitted with the sub-board and an outer periphery fitted into a through space of the main board. 3. An insulating frame provided on the main substrate in an upright state and surrounding the sub-substrate and the flexible electrical connection means, and filled in the insulating frame to fill the insulating frame. 3. A filler having electrical insulation performance in which the arranged electric components are sealed.
An electronic device according to any one of the above. 4. A sub-board, which is provided on the main board in an upright state,
An insulating frame disposed around the flexible electrical connection means and the high-voltage circuit portion provided on the main board; and an electric component filled in the insulating frame and disposed in the insulating frame. The electronic device according to claim 1, further comprising a filler having stopped electrical insulation performance. 5. The electronic device according to claim 3, wherein the filler is made of a transparent material. 6. An insulating sheet made of an electrically insulating material disposed between a cooling fin provided on the sub-substrate and facing the main substrate and the main substrate. An electronic device according to claim 1. 7. A cooling fin made of a material that does not deform or deteriorate in performance with respect to the temperature of the cooling fin, and is disposed between the cooling fin provided on the sub-substrate and facing the main substrate and the main substrate. The electronic device according to claim 1, further comprising a heat-resistant sheet.