JP2001111267A - Electronic controlling device and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make operational reliability for heat superior while size-expansion of a device and an increase in manufacturing cost are suppressed in an electronic control device. SOLUTION: A drive element 5 (5a and 5b) from which a large quantity of heat is easy to generate and a control process element 3 that is easy to be affected by the heat are mounted onto separate boards 9 and 11 different from each other. Consequently, it is suppressed that the heat generated from the drive element 5 reaches the control process element 3. Furthermore, a flexible printed wiring board 13 for connecting both the boards 9 and 11 to each other is joined to the control circuit board 9 by a rear side of a placing area in the control circuit board 9 of a connector 2. Thus, even if the flexible board 13 is joined to the control circuit board 9, no obstacle for designing a layout is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic control device for driving and controlling an external control object and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, an external control object (for example, various actuators such as an electromagnetic solenoid) is supplied with electric power to be driven, and an electronic control device (for example, an engine control or a speed changer) for controlling the operation is provided. An in-vehicle electronic control device that performs control is known. This type of electronic control device includes, for example, as shown in FIG.
The control processing element 103 and the driving element 105 are
It is constituted by accommodating in. Control processing element 1
Reference numeral 03 denotes a unit that performs a calculation process or the like based on a signal input from the outside via the connector 102 and outputs a control signal, and is, for example, a CPU or a microcomputer. The drive element 105 is driven by a control signal from the control processing element 103 and supplies power to an external control target, and is, for example, a power transistor or a power IC.

In this type of electronic control device,
From the viewpoint of improving productivity and reducing costs, the control processing element 103 and the driving element 105 have been mounted on the same circuit board 109 as shown in FIG. However, the driving element 105 handles a larger current (that is, electric power) than the control processing element 103 and the like, and generates a large amount of heat there. On the other hand, the control processing element 103 that performs various arithmetic processes is easily affected by heat, and therefore, the heat generated by the driving element 105 is generated by the control processing element 1.
It is conceivable that the temperature of 03 may be excessively increased to make the operation unstable.

Generally, the circuit board 109 on which the control processing element 103 and the driving element 105 are mounted is a resin substrate having relatively low thermal conductivity among various circuit boards. Above, the positional relationship between the control processing element 103 and the driving element 105 was taken into consideration, for example, as much as possible. By doing so, the heat generated in the driving element 105 is less likely to reach the control processing element 103. FIG. 6 (a)
FIG. 6B shows a configuration of the electronic control device viewed from a direction parallel to the substrate surface of the circuit board 109, and FIG. 6B shows a configuration of the electronic control device viewed from a direction perpendicular to the substrate surface of the circuit board 109. 2 shows the configuration.

[0005]

However, in recent electronic control devices, the number of drive elements 105 and the power handled by the drive elements 105 have increased due to the sophistication and multifunctionality of the control contents. I'm advancing. Accordingly, the amount of heat generated in the driving element 105 tends to increase.
Even in this case, it is conceivable to suppress the thermal influence on the control processing element 103 by enlarging the circuit board 109 and further separating the control processing element 103 and the driving element 105. However, when the space for mounting the electronic control device is limited (for example, when the electronic control device is mounted on an automobile), there is a limit from the viewpoint of space saving. Also, if the area of the circuit board 109 is increased, the production yield of the circuit board 109 will be reduced, and as a result, the production cost of the electronic control unit may increase.

For this reason, in recent electronic control devices,
It is becoming difficult to suppress the thermal effect of the heat generated by the drive element 105 on the control processing element 103. Further, if the amount of heat generated by the drive element 105 increases in the future, there is a possibility that the heat dissipation performance of the conventional electronic control device will be exceeded. In that case, the driving element 105
The generated heat may not be sufficiently dissipated, and the operation of not only the control processing element 103 but also the driving element 105 itself may become unstable.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide an electronic control device with good operation reliability against heat while suppressing an increase in the size of the device and an increase in manufacturing cost. And

[0008]

Means for Solving the Problems and Effects of the Invention In the electronic control device according to the present invention (claim 1) to solve the above-mentioned problems, at least a part of the wall surface of the housing is configured as a heat sink. The driving circuit includes a driving circuit board, a control processing element, and a circuit board for mounting the connector. The driving circuit board includes a driving circuit board and a control circuit board that are arranged substantially parallel to each other.

The drive circuit board is provided in close contact with the inside of a wall as a heat sink, and a drive element is mounted on the board surface. The control circuit board has a control processing element and a connector mounted thereon. The control circuit board is arranged to face the drive circuit board and is connected to the drive circuit board by connection wires. The connecting portion of the connection wire on the control circuit board is arranged near the connector.

That is, in the electronic control device according to the present invention (claim 1), a drive element that easily generates a large amount of heat;
Since the control processing elements that are easily affected by heat are mounted on different substrates different from each other, it is possible to make it difficult for heat generated by the driving elements to reach the control processing elements. Therefore, even if the power handled by the driving elements increases or the number of driving elements increases, the amount of heat generated in the driving elements increases, so that the influence of heat on the control processing elements can be suppressed. become.

Further, since a part of the wall surface of the housing of the electronic control device is formed as a heat sink, and the drive circuit board on which the drive elements are mounted is provided in close contact with the wall surface as the heat sink. Even if the drive element generates heat, the heat can be quickly released to the outside of the housing (that is, outside of the electronic control device) via the heat sink. Therefore, it is possible to further suppress the influence of the heat generated by the driving element on the control processing element, and to suppress the temperature rise of the driving element itself.

Since the drive circuit board is provided in close contact with the heat sink, it is not easy to dispose the connector on the drive circuit board. Therefore, the connector is preferably provided on the control circuit board. In the electronic control device according to the present invention (claim 1), since the control circuit board and the drive circuit board are arranged so as to face each other, it is possible to suppress the thermal influence on the control processing element. At the same time, an effect is obtained that the size of the apparatus can be suppressed. That is, when arranging the drive circuit board and the control circuit board in the housing, for example, it is possible to arrange them so that the two boards do not overlap each other. However, the housing becomes large. In the electronic control device according to claim 1,
By arranging the control circuit board and the drive circuit board so as to overlap with each other (that is, with their board surfaces facing each other), it is possible to suppress an increase in the size of the device.

By the way, when the circuit board is divided into the control circuit board and the drive circuit board as described above, and the electrical connection between the two boards is established by connection wires, depending on the joining position of the connection wires on the control circuit board, The circuit design of the control circuit board may be difficult. That is, the power handled by the driving element tends to increase due to the recent sophistication of the control processing contents of the electronic control unit, and accordingly, a wiring pattern (wiring pattern for the current path) for forming a current path to the control target. It is necessary to increase the width. In addition to this,
The number of driving elements is also increasing. Since the power supply (power supply) to the external control target is performed via the connector on the control circuit board, the wiring pattern for the current path on the control circuit board depends on the connection portion of the connection wire on the control circuit board. Becomes long and occupies a large area.

However, in the control circuit board, since various signals handled by the control processing element are input / output via the connector, if the area occupied by the wiring pattern of the current path is large, the overall wiring pattern This makes the circuit design of the control circuit board, such as the layout, difficult.
As a result, there is a possibility that the design period is prolonged or the wiring pattern is unnecessarily complicated, which leads to an increase in manufacturing cost.

Therefore, the electronic control device according to the present invention (claim 1) employs a configuration in which the connection portion of the connection wire on the control circuit board is located near the connector. This makes it possible to reduce the area occupied by the wiring pattern for the current-carrying path on the control circuit board, thereby reducing the difficulty in circuit design as described above. and again,
Since the path between the drive element and the connector is also shortened,
The voltage drop during that time can be suppressed.

In order to further reduce the difficulty of circuit design, it is preferable to make the circuit as described in claim 2. That is, the connector is provided on the back side of the surface of the control circuit board facing the drive circuit board (that is, the surface of the control circuit board opposite to the drive circuit board), and the connector is provided on the control circuit board. The back side of the part (also called "the part behind the connector")
Then, the connection wire is joined to the control circuit board.

That is, the portion behind the connector has a small number of wiring patterns from the connector to the control processing element, and is a portion where components for noise suppression are mainly arranged. Is high. Therefore, if the connection wires are joined at the site behind the connector as described in claim 2, the restrictions in designing the layout can be greatly reduced.

Further, since the connector is provided on the control circuit board on the back side of the surface facing the drive circuit board, the surface to which the connection wires are joined is on the side facing the drive circuit board. Therefore, the connection between the control circuit board and the drive circuit board which are arranged to overlap with each other (that is, to face each other) can be easily performed.

Various arrangements of the connector on the control circuit board and connection portions of the connection wires on the two boards are conceivable. However, when the layout of other electronic components and wiring patterns is further taken into consideration, the present invention is further described in claim 3. It is preferable to adopt the following configuration. That is, by arranging the connector at the end of the control circuit board, the connecting portion of the connection wire is located at the end of the control circuit board, and the connecting portion of the connection wire on the drive circuit board is also positioned at the end of the drive circuit board. That is.

According to the third aspect of the present invention, the connector is provided at the end of the control circuit board, and the connection wires are also joined at the ends of both boards. Therefore, the degree of freedom in layout of wiring patterns and electronic components (including control processing elements and driving elements) is further increased, which is preferable. In addition, since the connection wires are joined at the ends of the two substrates, an effect that the connection wires can be easily joined to both the substrates by, for example, a method described below (claim 6). Also play.

As the connection wires, wires each having a separate structure may be used. However, in this case, it is necessary to perform bonding to the drive circuit board and the control circuit board one by one. This may be troublesome and may increase the number of parts, which may increase the manufacturing cost.

Therefore, it is preferable to use a flexible printed wiring board as the connection wire. That is, the flexible printed wiring board is a thin strip-shaped substrate, takes up no space, and can form a large number of wiring patterns. Therefore, the electronic control device can be further reduced in size, and the number of parts can be reduced. Also, as described later (claim 6)
In addition, there is an effect that the connection between the control circuit board and the drive circuit board can be easily achieved.

In the electronic control device according to the fourth aspect, the flexible printed wiring board includes a control signal from the control processing element to the drive element and an electric power to be supplied from the drive element to an external control object via the connector. Will pass. Since the control signal is a very small current, a narrow wiring pattern for transmitting it is sufficient.However, since the current for supplying power to the external control target is large, the voltage drop or heat generation in the flexible printed wiring board is large. In order to prevent this, it is necessary to increase the width of the wiring pattern. However, if the width of all wiring patterns is increased, the width of the entire flexible printed wiring board is increased,
The electronic control device will be increased in size.

Therefore, it is preferable to adopt a configuration as described in claim 5. In other words, of the wiring patterns formed on the flexible printed wiring board, the wiring pattern that forms an energizing path from the driving element to the control target via the connector forms a transmission path of a control signal from the control processing element to the driving element. It is formed so as to be wider than the wiring pattern to be formed.

According to the electronic control apparatus of the fifth aspect, the width of the wiring pattern for transmitting power to the control target is made wider than that of the wiring pattern for transmitting control signals. Further, it is possible to prevent a voltage drop and heat generation in the flexible printed wiring board while suppressing an increase in the size of the flexible printed wiring board. That is, by changing the width of the wiring pattern according to the magnitude of the current to be transmitted, it is possible to reduce the overall width of the flexible printed wiring board, thereby suppressing an increase in the size of the electronic control device. Can also be achieved.

According to the sixth aspect of the present invention, an electronic control device having the configuration described in the fourth and fifth aspects can be easily manufactured. That is, first, the drive circuit board on which the drive element is mounted and the control circuit board on which the control processing element and the connector are mounted are arranged side by side on the same plane. At this time, the drive circuit board is arranged on the end of the control circuit board where the connector is provided. Also, the two substrates are arranged so that the surfaces of the substrates that face each other face the same direction. Then, a flexible printed wiring board is joined to the adjacent ends of both substrates arranged in this state by soldering from one side of the plane. As a result, the control circuit board and the drive circuit board are electrically connected to each other, and then both these boards are housed in the housing.

That is, as described above, the connection portions of the connection wires in the connection between the control circuit board and the drive circuit board are set at the ends of the both substrates (claim 3), and the flexible printed wiring board is used as the connection wires ( According to a fourth aspect of the present invention, the two substrates can be easily connected by the method according to the sixth aspect. As a result, the manufacturing process of the electronic control device can be simplified, and the manufacturing cost can be reduced.

Here, the soldering is performed by bringing the flexible printed wiring board into contact with the ends of both substrates using a high-temperature crimping jig or the like. Specifically, for example, solder is previously attached to a joint portion of both substrates to be joined to the flexible printed wiring board, and the solder is melted, so that the two boards can be joined to the flexible printed wiring board. Conceivable.

In order to provide the drive circuit board in close contact with the heat radiating plate, an adhesive having excellent thermal conductivity is used. Such an adhesive is used for a predetermined time (for example, about 30 minutes) and at a high temperature (for example, (About 150 ° C.), it is often necessary to cure the resin. In the case of this type of adhesive, the curing of the adhesive is performed by placing the drive circuit board and the heat sink in close contact with each other and placing it at a high temperature. Is not preferred. That is, if the drive circuit board and the control circuit board connected to it are also placed at a high temperature, there is a possibility that a failure occurs in the control processing element, and only the drive circuit board and the heat sink are placed at a high temperature. Is difficult.

Therefore, it is preferable that the drive circuit board is brought into close contact with the heat radiating plate before the control circuit board and the drive circuit board are connected to each other by the flexible printed wiring board. In this case, the above-described problem does not occur, and the electronic control device according to claim 4 or 5 can be easily manufactured.

[0031]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram illustrating a configuration of an electronic control device 1 as one embodiment. This electronic control unit 1
Are driven and controlled by driving various actuators (ignition plugs, electromagnetic solenoids, etc., that is, corresponding to “control target” in the claims; not shown) provided in the engine (not shown) of the automobile. It is for performing engine control, and includes a connector 2, a control processing element 3, and a driving element 5 (5a, 5b).

The connector 2 is for the electronic control unit 1 to exchange signals with an external control object. The control processing element 3 of the present embodiment is a microcomputer configured as a so-called one-chip microcomputer, and receives input signals from various sensors for detecting the operating state of the engine via the connector 2 and inputs the signals. A control process (arithmetic process) based on the signal is performed, and a control signal corresponding to a result of the control process is output to the driving element 5. The control processing element 3 also communicates with various electronic devices (not shown) mounted on the vehicle via the connector 2.

The control processing element 3 is housed in a housing 7 constituting the outer shape of the electronic control unit 1, and is mounted on a control circuit board 9 inside the housing 7. The control circuit board 9 is a board made of resin (in this embodiment, a board made of glass cloth as a base material and impregnated with epoxy resin), and forms a control circuit for controlling an external actuator. Substrate. A plurality of electronic components (not shown) are mounted on the control circuit board 9 in addition to the control processing element 3, and constitute a predetermined control circuit together with the control processing element 3.

The control circuit composed of the control processing element 3 considers that a large number of signals such as signals from external sensors (not shown) and communication signals from external electronic devices are handled, and The connector 2 is provided on the control circuit board 9 in consideration of ease of mounting. The connector 2 has connector pins 8 for electrically connecting to a predetermined circuit board, and is electrically connected to a wiring pattern on the control circuit board 9 via the connector pins 8.

The control circuit board 9 is so positioned that its board surface faces the board surface of the drive circuit board 11 (described later).
It is arranged in parallel with the drive circuit board 11. The connector 2 and the control processing element 3 are
The surface facing the drive circuit board 11 (in FIG. 1A,
The connector 2 is provided on the back side surface (i.e., the upper surface) of the control circuit board 9, and the connector 2 is provided at an end of the control circuit board 9. FIG. 1A shows the configuration of the electronic control unit 1 as viewed from a direction parallel to the board surface of the control circuit board 9, and FIG. 1 shows a configuration of an electronic control unit 1 as viewed from a vertical direction.

On the other hand, the driving element 5 is for supplying electricity to the actuator of the engine and driving it.
That is, the drive element 5 is a so-called switching element, and is provided on an energization path from an on-vehicle battery (not shown) external to the electronic control unit 1 to each actuator, and this energization path is used as a control signal from the control processing element 3. It is configured to be intermittent based on

The drive element 5 is also provided inside the housing 7 like the control processing element 3, but is different from the control circuit board 9 on which the control processing element 3 is mounted (the drive circuit board 1).
It is implemented in 1). The drive circuit board 11 on which the drive elements 5 are mounted is a ceramic board having excellent heat dissipation, and is a board for forming a drive circuit that forms a part of an energization path for energizing each actuator. is there.
Various electronic components (not shown) including the drive element 5 are mounted on a surface (upper surface) of the drive circuit board 11 facing the control circuit board 9, and a predetermined drive circuit is formed.

As shown in FIG. 2, the driving element 5 of this embodiment is a so-called bare chip type (a type in which a semiconductor chip is not housed in a package such as a resin). The required power differs for each actuator to be controlled, and the amount of heat generated in each drive element 5 also differs. Therefore, different types of power are used in accordance with the difference in the amount of power (that is, the difference in the amount of heat). May be used. That is, when it is considered that a large amount of heat is generated, as shown in FIG. 2A, a driving element 5a of a type in which a semiconductor chip 6b is mounted on a substrate via a radiation fin 6a.
When the calorific value is relatively small using FIG.
As shown in FIG. 5, a driving element 5b of a type in which the semiconductor chip 6b is directly mounted on a substrate without using a heat radiation fin is used.
The term "driving element 5" includes the different types of driving elements 5a and 5b described above.

The drive element 5 is mounted on the wiring pattern formed on the substrate, and one of the electrodes of the drive element 5 (collector electrode in this embodiment) is directly or radiated to the radiation fin 6a. Through the wiring pattern. The other electrodes (the base electrode and the emitter electrode in this embodiment) are electrically connected to the wiring pattern via bonding wires 6c such as gold or aluminum.

The control circuit board 9 on which the control circuit composed of the control processing element 3 is formed and the drive circuit board 11 on which the drive circuit composed of the drive element 5 is formed are connected to a flexible printed wiring board 13 as a "connection wire". (Hereinafter simply referred to as “flexible substrate 13”). The flexible substrate 13 has excellent elasticity, is joined to the ends of the control circuit board 9 and the drive circuit board 11 by soldering, and is electrically connected to the wiring patterns of the boards 9 and 11.

The joint portion of the flexible board 13 on the control circuit board 9 is located near the connector 2, and specifically, is provided on the back side of the portion where the connector 2 is provided on the control circuit board 9. ing. The flexible substrate 13 is bent in a U-shape between the substrates 9 and 11 so as to have an appropriate flexure, and the casing 7 (particularly, a casing bottom 7b and a casing cylinder 7c described later).
And a substrate supporting portion 7f).

Here, FIG. 3 shows the control circuit board 9 and the drive circuit board 11 connected by the flexible board 13.
FIG. 4 is a diagram showing surfaces facing each other. That is, FIG.
Is shown from the direction of the upper surface of the drive circuit board 11, but the control circuit board 9 is shown in a state of being inverted by 180 degrees around the flexible board 13 (that is, in a state of being turned upside down). As will be described later, the lower surface of the drive circuit board 11 is provided in close contact with the housing bottom 7b as a heat sink.

Next, an example of a signal flow in the electronic control unit 1 of this embodiment will be described with reference to FIG. When a signal (sensor signal) from an external sensor is transmitted to the connector 2, the sensor signal is transmitted to the connector pins 8 a and the upper surface of the control circuit board 9 (that is, the back surface of the surface facing the drive circuit board 11). The signal is transmitted to the input terminal of the control processing element 3 via the formed wiring pattern 15a. Various signals are input to the control processing element 3 via paths other than those illustrated. Then, the control processing element 3 performs arithmetic processing based on the input various signals, and outputs a control signal for driving and controlling an external control target.

From the output terminal of the control processing element 3 to the driving element 5
Is output via a wiring pattern 15b formed on the upper surface of the control circuit board 9, a via hole 17 penetrating the control circuit board 9, and a wiring pattern 15c formed on the lower surface of the control circuit board 9. And transmitted to the flexible substrate 13. In the present embodiment, the wiring pattern 15c is formed so as to pass between the connector pins 8 because the connection portion of the flexible substrate 13 in the control circuit board 9 is arranged on the back side of the connector 2.

The control signal is transmitted to the flexible substrate 13
Is transmitted to the drive circuit board 11 through the wiring pattern 19a, and further, through the wiring pattern 21a formed on the upper surface of the drive circuit board 11, the input terminal of the drive element 5b (base electrode in this embodiment). Is transmitted to And
The drive element 5b is turned on or off in response to a control signal, and connects or cuts off a current supply path of an external actuator.

When the driving element 5b is turned on,
Wiring pattern 21 formed on upper surface of drive circuit board 11
b, the wiring pattern 19b of the flexible board 13 and the wiring pattern 15 formed on the lower surface of the control circuit board 9
The energization path composed of d, the connector pin 8b, and the like is brought into a connected state, and energization of the actuator is performed. The wiring patterns 15d, 19b, and 21b that form the energization paths of the external control target are wiring patterns 15a to 15c that form sensor signal and control signal transmission paths so that heat generation and voltage drop can be suppressed even when a large current flows. , 19
a, 21a.

The control circuit boards 9 thus connected to each other
The drive circuit board 11 is housed in the housing 7 (FIG. 1). The wall surface of the housing 7 that accommodates these substrates 9 and 11 is formed by casting metal (aluminum in this embodiment), and includes a housing lid 7a, a housing bottom 7b,
And a housing cylinder 7c.

The housing lid 7a is formed as a cylindrical body having one end (closed end) closed, and a side opening 7 for exposing the connector 2 to the outside is formed on the side surface of the cylindrical body.
d is formed. An end opening 7e having substantially the same shape as the control circuit board 9 is formed at an end of the housing lid 7a opposite to the closed end, and the control circuit board 9 is inserted into the end opening 7e. It is configured so that it can be fitted. When the control circuit board 9 is fitted into the end opening 7e, the housing cover 7a covers the surface of the control circuit board 9 on which the connector 2 is arranged.

The housing bottom 7b is disposed on the opposite side of the control circuit board 9 from the housing lid 7a via a housing cylinder 7c. The housing bottom 7b is for facilitating the release of heat generated by the electronic control device 1 (particularly, the driving element 5) to the outside of the housing 7, and is configured to absorb the heat quickly. It is configured as a thick (for example, thicker than the housing lid 7a) heat sink. Then, the heat generated in the driving element 5 is efficiently radiated by the housing bottom 7b.
The drive circuit board 11 has a surface inside the housing bottom 7b (FIG. 1).
It is provided in close contact with (upper side in (a)). That is, the case bottom 7b is defined as the “wall as a heat sink” in the claims.
Is equivalent to

The casing cylinder 7c has the same cross section as the casing lid 7a, and is formed as a tubular body having both ends opened. The casing lid 7a and the casing bottom are formed at both ends. 7b. As shown in FIG. 1A, the housing cylinder 7c forms a side surface of the housing 7 together with the housing lid 7a, and includes the control circuit board 9 and the drive circuit board 11 (that is, the control circuit board 9).
The space between the housing 7 and the housing bottom 7 b) is shielded from the space outside the housing 7. Note that a board supporting portion 7f for supporting the control circuit board 9 is provided in the housing cylinder portion 7c.

In order to assemble the electronic control unit 1 having the above configuration, it is preferable to perform the following order (FIG. 4).
reference). First, an electronic component including the drive element 5a is mounted on the drive circuit board 11 to form a predetermined drive circuit. Then, the lower surface of the drive circuit board 11 on which the drive circuit is mounted (that is, the back surface of the mounting surface of the drive element 5) is brought into close contact with the housing bottom 7b as a heat radiating plate (see FIG. 4A). In order to bring the drive circuit board 11 and the housing bottom 7b into close contact with each other, they are bonded to each other via an adhesive having excellent thermal conductivity and kept at a high temperature (for example, about 150 ° C.) for a predetermined time (for example, about 30 minutes). By heat-curing the adhesive in this manner, the drive circuit board 11 and the housing bottom 7b are adhered in close contact with each other, and the thermal resistance between the drive circuit board 11 and the housing bottom 7b is reduced.

On the other hand, various electronic components including the connector 2 and the control processing element are mounted on the control circuit board 9 to form a predetermined control circuit. Next, the drive circuit board 11 adhered to the housing bottom 7b and the control circuit board 9 are arranged on the same plane S. At this time, both substrates 9,
The surfaces to be opposed to each other are oriented in the same direction.
Then, the flexible substrate 13 is approached from one side of the plane S (specifically, the surfaces of the two substrates 9 and 11 that are to be opposed to each other), and the mutually adjacent ends of the two substrates 9 and 11 are arranged side by side. Then, the flexible substrate 13 is joined by soldering by thermocompression bonding (see FIG. 4B).
Solder is adhered to the surfaces of the substrates 9 and 11 to be joined, and a pre-heated crimping jig (not shown)
Then, the flexible substrate 13 is brought into contact and its solder is melted, so that the two substrates 9, 11 and the flexible substrate 13 are joined.

Thereafter, as shown in FIG. 4C, the drive circuit board 11 (or the control circuit board 9 or both boards 9 and 11) is rotated about the flexible board 13 so that both the boards 9 and 9 are rotated. 11 are opposed to each other (that is, the two substrates 9 and 11 are overlapped) and housed in the housing 7 described above.

According to the electronic control unit 1 of the present embodiment configured as described above, the following effects can be obtained. (1) Since the driving element 5 and the control processing element 3 are mounted on different substrates 9 and 11 different from each other, the driving element 5
, The heat transmitted to the control processing element 3 can be reduced. Therefore, even if the power handled by the driving element 5 increases or the number of the driving elements 5 increases in the future, the amount of heat generated in the driving element 5 increases, but the influence of heat on the control processing element 3 is not affected. It can be suppressed.

(2) The housing bottom 7b of the electronic control unit 1 is configured as a heat sink, and the drive circuit board 11 on which the drive element 5 is mounted is in close contact with the inner surface of the housing bottom 7b as the heat sink. Therefore, even if the driving element 5 generates heat, the heat can be quickly released to the outside of the housing 7 (that is, outside of the electronic control unit 1) via the heat radiating plate. Therefore, it is possible to further suppress the influence of the heat generated by the driving element 5 on the control processing element 3 and also suppress the temperature rise of the driving element 5 itself.

(3) Control circuit board 9 and drive circuit board 11
Are disposed so as to face each other, so that an effect that an increase in the size of the electronic control device 1 can be suppressed can be achieved. (4) The joint portion of the flexible board 13 in the control circuit board 9 is provided near the connector 2. Specifically, the connector 2 is provided on the back side of the surface of the control circuit board 9 facing the drive circuit board 11, and at the back side of the portion of the control circuit board 9 where the connector 2 is provided, The flexible board 13 is joined to the control circuit board 9. Therefore, the flexible circuit board 1 is attached to the control circuit board 9.
3 can be greatly reduced in layout problems that may occur due to joining.

(5) Since the connector 2 is disposed on the control circuit board 9 on the back side of the surface facing the drive circuit board 11, the surface to which the flexible board 13 is bonded is opposed to the drive circuit board 11. Side. Therefore, the connection between the control circuit board 9 and the drive circuit board 11 arranged so as to overlap with each other (that is, to face each other) can be easily performed.

(6) Since the connector 2 is disposed at the end of the control circuit board 9 and the flexible board 13 is also joined at the ends of both boards 9 and 11, the wiring pattern and the electronic components (control The degree of freedom of the layout of the processing element 3 and the driving element 5 can be further increased.

(7) Control circuit board 9 and drive circuit board 11
Since the flexible board 13 is used as a "connection wire" for connecting the electronic control device 1 and the electronic control device 1, the electronic control device 1 can be further reduced in size and the number of components can be reduced. (8) Among the wiring patterns formed on the flexible substrate 13, a wiring pattern 19 b constituting an energization path from the drive element 5 to the control target via the connector 2 is transmitted to the control signal from the control processing element 3 to the drive element 5. Are formed so as to be wider than the wiring pattern 19a constituting the transmission path. Therefore, it is possible to prevent a voltage drop and heat generation in the flexible substrate 13 while suppressing an increase in the size of the flexible substrate 13.

(9) Drive circuit board 11 and control circuit board 9
Are arranged on the same plane, and both substrates 9,
The control circuit board 9 and the drive circuit board 11 are electrically connected to each other by bonding the flexible board 13 to the adjacent ends of the board 11 from one side of the plane by soldering by thermocompression bonding. . According to this method, the electrical connection between the substrates 9 and 11 can be easily achieved, and the manufacturing process of the electronic control device 1 can be simplified. It becomes possible to suppress.

(10) Control circuit board 9 and drive circuit board 11
Since the drive circuit board 11 is brought into close contact with the housing bottom portion 7b before they are connected to each other by the flexible board 13, the manufacturing process of the electronic control device 1 can be further simplified. . As mentioned above, although one Example of this invention was described, this invention is not limited to the said Example, It can take various aspects.

For example, in the electronic control unit of the above-described embodiment, the description has been made assuming that the actuator provided on the engine of the automobile is driven and controlled. However, it is apparent that the present invention is not limited to this. Further, in the above-described embodiment, as shown in FIG. 2, it has been described that a bare-chip type transistor is used as the driving element 5, but the present invention is not limited to this. For example, FIG.
As shown in (1), a drive element 5c of a type obtained by molding a resin around the semiconductor chip 6b (so-called mold type) may be used. The drive element 5c of the mold type shown in FIG. 5A has an electrode lead 6d fixed to a resin portion 6e together with a semiconductor chip 6b, and is connected to a wiring pattern via the electrode lead 6d and the radiation fin 6a. Connected. The electrode lead 6d is connected to the semiconductor chip 6b via a bonding wire 6c, and the radiation fin 6a is directly connected to the semiconductor chip 6b. Even when such a driving element 5c is used, the same configuration as that of the electronic control device 1 of the above embodiment may be used (FIG. 5B,
(C)).

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an overall configuration of an electronic control device according to an embodiment.

FIG. 2 is an explanatory diagram illustrating a configuration of a driving element according to an embodiment.

FIG. 3 is an explanatory diagram for explaining an example of a state in which a signal flows in a control circuit board and a drive circuit board connected to each other by a flexible board.

FIG. 4 is an explanatory diagram showing a procedure for connecting a control circuit board and a drive circuit board with a flexible board.

FIG. 5 is an explanatory view showing another embodiment of the electronic control device according to the present invention.

FIG. 6 is an explanatory diagram showing a conventional electronic control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electronic control device, 2 ... Connector, 3 ... Control processing element,
5 (5a to 5c): drive element, 7: housing, 7a: housing lid, 7b: housing bottom, 7c: housing cylinder, 8 (8a, 8)
b) connector pin, 9 control circuit board, 11 drive circuit board, 13 flexible printed wiring board (connection wire), S ... plane.

Claims (7)

[Claims] 1. A connector for transmitting and receiving signals to and from an external device on a predetermined circuit board disposed inside a housing, and a drive element for supplying electricity to an external control object via the connector. A control processing element that controls a control target by performing a control process based on an input signal input from the outside via the connector, and outputting a control signal according to the result of the control process to drive the drive element And at least a part of the wall surface of the housing is configured as a heat sink, and the circuit board is provided in close contact with the inside of the wall surface as the heat sink, and the drive element A drive circuit board on which the control processing element and the connector are mounted. It includes a road substrate, the bonding site in the control circuit board of the connecting wires, the electronic control unit, characterized in that in the vicinity of the connector. 2. The control circuit board according to claim 2, wherein
The connecting portion of the connection wire on the control circuit board is disposed on a back side of a surface facing the drive circuit board, and is a rear side portion of the connecting portion of the connector on the control circuit board. The electronic control device according to claim 1. 3. The drive circuit board, wherein the connector is disposed at an end of the control circuit board, and a joining portion of the connection wire on the drive circuit board is an end of the drive circuit board. 3. The electronic control device according to 1 or 2. 4. The electronic control device according to claim 3, wherein the connection wire is a flexible printed wiring board. 5. A wiring pattern that forms an energization path from the driving element to the control target via the connector among the wiring patterns formed on the flexible printed wiring board, wherein the wiring pattern is formed from the control processing element to the driving element. The electronic control device according to claim 4, wherein the electronic control device is formed to be wider than a wiring pattern forming a transmission path of the control signal that reaches the control signal. 6. The method for manufacturing an electronic control device according to claim 4, wherein the drive circuit board on which the drive element is mounted, and the control circuit board on which the control processing element and the connector are mounted. Are arranged side by side on the same plane, and the flexible printed wiring board is joined to adjacent ends of the arranged substrates by soldering from one side of the plane, so that the control circuit board and the drive circuit are joined together. A method of manufacturing an electronic control device, comprising: electrically connecting a board to each other; and then housing the connected boards in the housing. 7. The method according to claim 1, further comprising, before electrically connecting the control circuit board and the drive circuit board to each other with the flexible printed circuit board, bringing the drive circuit board into close contact with the heat sink. The method for manufacturing an electronic control device according to claim 6.