JP4684338B2 - Electronic control unit - Google Patents

Description

  The present invention relates to an electronic control device used in an electric power steering device that assists and energizes a steering device of a vehicle by the rotational force of an electric motor, for example.

Conventionally, a semiconductor switching element (FET), which is a power device, is mounted on a metal substrate, and a connecting member for electrically connecting the metal substrate and a component outside the metal substrate is mounted on the metal substrate. Control devices are known.
For example, in the electronic control device described in Patent Document 1, a power board on which a bridge circuit including a semiconductor switching element for switching the current of an electric motor is mounted, a conductive plate, and the like are insert-molded in an insulating resin. In addition, a housing on which a large current component is mounted, a control board on which a small current component such as a microcomputer is mounted, a connecting member that electrically connects the power board to the housing and the control board, and a power board And a case attached to the heat sink and press-molded with a metal plate to cover the power board, the housing and the control board.

  In addition, the electronic control device described in Patent Document 2 includes a cover, a printed circuit board, a case, and a housing, and an engagement portion that is a snap fit formed around the cover is formed on the case. By engaging with the engaging portion, the cover is detachably attached to the case.

Japanese Patent No. 3644835 (FIG. 2) Japanese Patent Laying-Open No. 2003-309384 (FIG. 3)

In the electronic control device described in Patent Document 1, a case in which a metal plate is press-molded covers the power board, the housing, and the upper and side surfaces of the main body of the control board, and the volume increases and the mass increases. There was a problem.
Further, there is also a problem that the caulking piece formed on the end face of the case is caulked to fix the case to the heat sink, and the fixing work is troublesome.

  In the electronic control device described in Patent Document 2, the snap fit formed around the cover is engaged with the engaged portion formed on the outer periphery of the case, and the snap fit is engaged. Since the part engaged with the part is exposed to the outside, there is a problem that the cover may come off from the case due to an external impact on the part.

  An object of the present invention is to solve the above-described problems, and it is possible to reduce the weight and size, improve the assembling workability, and improve the reliability of the attachment of the cover to the housing. An object of the present invention is to provide an electronic control device such as

An electronic control device according to the present invention includes an insulating resin housing having openings at both ends, a heat sink attached to one end of the housing, a power device mounted on the heat sink, A circuit board provided opposite to the heat sink and formed with an electronic circuit including a control circuit for controlling the power device, and attached to the other end of the housing, and in cooperation with the heat sink, A cover made of an insulating resin storing the power device and the circuit board; and an attaching means for attaching the cover to the housing. The attaching means includes a locking protrusion formed on the cover; A locking hole formed, and the locking protrusion is inserted and locked into the locking hole, Bar is attached to the housing, the cover, the base portion of the locking projections are positioned with respect to the housing fitted in the insertion opening of the locking hole.

  According to the electronic control device of the present invention, since the cover and the housing are made of insulating resin, the weight can be reduced, and the locking protrusion of the cover is inserted and locked in the locking hole of the housing. Since the cover is attached to the housing, it is possible to reduce the size, improve the assembling workability, and improve the reliability of the mounting property of the cover to the housing.

It is a disassembled perspective view which shows the electronic control apparatus which concerns on Embodiment 1 of this invention. It is a sectional side view of the electronic control unit of FIG. It is a cross-sectional perspective view when cut along a direction perpendicular to the side cross section of the electronic control device of FIG. FIG. 3 is a cross-sectional perspective view when the electronic control device of FIG. 1 is cut along the same direction as the side cross section of the electronic control device of FIG. 2 and viewed from the opposite direction to FIG. 2. FIG. 4 is a cross-sectional perspective view when the electronic control device of FIG. 1 is cut in parallel with the cross section of the electronic control device of FIG. 3. It is a perspective view which shows the cover of FIG. It is principal part sectional drawing which shows the electronic controller which concerns on Embodiment 2 of this invention.

Hereinafter, the electronic control device according to each embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or equivalent members and parts will be described with the same reference numerals.
Embodiment 1 FIG.
1 is an exploded perspective view showing an electronic control unit 1 according to Embodiment 1 of the present invention, FIG. 2 is a side sectional view of the electronic control unit 1 in FIG. 1, and FIG. 3 is a side sectional view of the electronic control unit 1 in FIG. FIG. 4 is a cross-sectional perspective view taken along a direction perpendicular to FIG. 2, and FIG. 4 is a view taken along the same direction as the side cross-section of the electronic control device 1 of FIG. 5 is a cross-sectional perspective view, FIG. 5 is a cross-sectional perspective view when the electronic control device 1 of FIG. 1 is cut in parallel with the cross section of the electronic control device 1 of FIG. 3, and FIG. It is a perspective view shown.

  The electronic control device 1 is mounted on the heat sink 5, a housing 3 made of insulating resin having a box shape having openings on both sides, an aluminum heat sink 5 attached to one opening of the housing 3, and the heat sink 5. A semiconductor switching element 2 as a power device, a circuit board 4 provided in parallel with the heat sink 5 and an electronic circuit including a control circuit for controlling the semiconductor switching element 2, and a housing 3 And a cover 7 made of insulating resin storing the semiconductor switching element 2 and the circuit board 4 in cooperation with the heat sink 5.

  The cover 7 has a locking projection 7a having a flange 7b formed at the end. The locking projections 7a are formed on the outer peripheral edge of the surface facing the circuit board 4 so that two of them are paired in the vertical direction and the flanges 7b are directed in opposite directions. A pair of locking projections 7a are formed on each side of the cover 7, and the locking projections 7a arranged on the opposite sides are points with respect to the center of the surface of the cover 7 on the circuit board 4 side. They are arranged symmetrically.

A locking hole 3c penetrating in the direction in which the locking projection 7a of the cover 7 is inserted is integrally formed with an insulating resin on the inner wall surface of each side wall 3b of the housing 3 surrounding the periphery. On the opposing surface of the inner wall surface of the locking hole 3c, a convex portion 3d to which the flange portion 7b of the locking projection 7a is locked and a pair of flange portions 7b are inserted as the locking projection 7a is inserted. A tapered portion 3e is formed which is gradually parallel to the side wall 3b of the housing 3 and elastically deformed in a direction approaching each other.
Therefore, when the pair of locking projections 7a are inserted into the locking holes 3c, the flange portions 7b of the locking projections 7a are gradually deformed inward by the tapered portions 3e, and the respective flange portions 7b are convex. The cover 7 is attached to the housing 3 by overcoming the portion 3d and engaging with the convex portion 3d.

In addition, a fitting portion 7c is formed at the base portion of the pair of locking projections 7a, and the fitting portion 7c is fitted into the insertion port 3f of the locking hole 3c so that the cover 7 and the housing 3 are positioned. Is done.
The locking hole 3c is provided with a heat sink 5 on the opposite side of the insertion port 3f, and the locking hole 3c is closed by the heat sink 5.
Note that the locking protrusion 7 a formed on the cover 7 and the locking hole 3 c formed on the housing 3 constitute mounting means for mounting the cover 7 to the housing 3.

Further, as shown in FIG. 2, the electronic control unit 1 has a base portion integrated with the housing 3 by insert molding with an insulating resin 3 a and electrically connected the circuit board 4 and the semiconductor switching element 2. As shown in FIG. 5, a conductive plate 6a, a conductive plate 6b in which the base portion is integrated with the housing 3 by insert molding with an insulating resin 3a and the circuit board 4 and the power connector terminal 8a are electrically connected. Further, a metal leaf spring 21 that is an elastic body that presses the insulating resin package of the semiconductor switching element 2 to bring the heat spreader hs into close contact with the heat sink 5 is provided.
The leaf spring 21 is fixed to the heat sink 5 with screws 20 through the housing 3.

The housing 3 is provided with a vehicle connector 8 electrically connected to a vehicle wiring on one side, and a motor connector 9 and a torque sensor (not shown) electrically connected to an electric motor (not shown) on the other side. A sensor connector 10 electrically connected to the sensor connector 10.
The vehicle connector 8 includes a power connector terminal 8a that is electrically connected to a vehicle battery (not shown), and a signal connector terminal 8b through which signals are input / output via wiring of the vehicle. The motor connector 9 includes a motor connector terminal 9a, and the sensor connector 10 includes a sensor connector terminal 10a.
The housing 3 includes a conductive plate 6a electrically connected to the circuit board 4 and the semiconductor switching element 2, a conductive plate 6b electrically connected to the power connector terminal 8a, a power connector terminal 8a, a signal connector terminal 8b, a motor. The connector terminal 9a, the sensor connector terminal 10a, and the like are insert-molded, and at the same time, the vehicle connector 8, the motor connector 9, and the sensor connector 10 are also formed integrally with the housing 3.
Further, on both side wall surfaces of the housing 3 on the opening side opposite to the opening on which the heat sink 5 is mounted, mounting leg portions 3L for mounting the electronic control device 1 to the vehicle as the mounted body are formed. .

In the semiconductor switching element 2, a high-side MOSFET and a low-side MOSFET are integrated to form a half bridge. In the semiconductor switching element 2, half bridges are housed in one package and a pair of two constitutes a bridge circuit for switching the current of an electric motor (not shown).
The terminals of the half-bridge semiconductor switching element 2 are composed of five terminals: a power supply terminal, a gate terminal of a high-side MOSFET, a bridge output terminal, a gate terminal of a low-side MOSFET, and a ground terminal. Here, the power supply terminal , the bridge output terminal, and the ground terminal are large current terminals through which a large current flows, and the gate terminal of the high side MOSFET and the gate terminal of the low side MOSFET are small current terminals for signals.

On the wiring pattern on the circuit board 4, a microcomputer 13 is mounted on the front surface, and a capacitor 14 for absorbing motor current ripple is mounted on the back surface by soldering.
Although not shown in FIG. 1, the wiring pattern on the circuit board 4 includes a coil and a shunt resistor that prevent the electromagnetic noise generated during the switching operation of the semiconductor switching element 2 from flowing out. Circuits and peripheral circuit elements are also mounted by soldering.
The circuit board 4 is formed with a plurality of through holes 4a whose inner surfaces are plated with copper. The through hole 4 a is electrically connected to the wiring pattern of the circuit board 4.

The heat sink 5 includes a heat sink body 5a and an alumite film 5b that is an insulating film formed on the surface of the heat sink body 5a. This heat sink 5 manufactures a heat sink material in which an alumite film 5b is formed in advance on the entire surface of a long extruded shape formed by extruding aluminum or an aluminum alloy from a die, and the heat sink material is cut to a desired length by a cutting machine. It is formed by cutting.
An outer peripheral end surface of one side of the heat sink 5 formed by cutting with a cutting machine is a cut surface 5c where the heat sink body 5a is exposed to the outside, and an alumite film 5b is formed on a surface other than the cut surface 5c. An alumite film 5b is also formed on the surface on which the semiconductor switching element 2 is mounted and on the back surface thereof.
The cut surface 5 c faces the inner wall surface of the side wall 3 b of the housing 3.

Here, the heat sink 5 is manufactured by using an extruded profile, but may be manufactured by cutting a heat sink material that has been hot or cold forged.
Further, it may be manufactured by cutting a hot or cold rolled plate material.
Further, four or a part of the outer peripheral end surface of the heat sink body 5a may be exposed to the outside, and the exposed surface may be opposed to the inner wall surface of the side wall 3b.

The leaf spring 21 presses the insulating resin package surface of the semiconductor switching element 2 so that the heat spreader hs that is a heat radiating portion of the semiconductor switching element 2 is brought into close contact with the surface of the heat sink 5 on which the alumite film 5b is formed. The heat spreader hs of the semiconductor switching element 2 is electrically connected to the bridge output terminal, but is electrically insulated from the heat sink 5 by the alumite film 5b.
The surface of the heat sink 5 has small irregularities, and a slight gap is generated even when the heat spreader hs of the semiconductor switching element 2 is brought into close contact with the heat sink 5 by the action of the leaf spring 21. Due to the slight gap, the thermal resistance of the heat conduction path for radiating the heat generated in the semiconductor switching element 2 to the heat sink 5 is increased. Therefore, in order to fill the gap, the heat spreader hs and the alumite film 5b of the heat sink 5 are adhered and fixed using an adhesive resin (not shown) having high thermal conductivity.

  As another means for filling the gap between the heat spreader hs of the semiconductor switching element 2 and the heat sink 5, high thermal conductivity grease may be interposed.

The plate spring 21 is formed of a copper alloy plate having spring properties such as a phosphor bronze plate for a spring by a press machine, and includes a pressing portion 21a that presses an insulating resin package of a pair of adjacent semiconductor switching elements 2. The holding portion 21b extends in a direction perpendicular to the presser portion 21a. The locking portion 21b is press-fitted and locked inside a pair of holding portions 3g formed integrally with the housing 3 with an insulating resin. Further, the leaf spring 21 has slits 21c formed in extending portions extending from both sides of one locking portion 21b.
The slit 21 c is press-fitted into a holding member H having a function of holding the circuit board 4 and connecting the ground of the circuit board 4 to the heat sink 5. The press-fit terminal portion Hp formed at the tip of the holding member H is press-fitted into the through hole 4a of the circuit board 4, and the circuit is passed through the press-fit terminal portion Hp, the holding member H, the leaf spring 21, and the screw 20. The wiring pattern of the substrate 4 and the heat sink 5 are electrically connected.
The plate spring 21 is made of a copper alloy plate having a spring property such as a phosphor bronze plate for a spring, but may be another metal material such as a stainless steel plate for a spring.

  The base end portion of the conductive plate 6a exposed from the insulating resin 3a of the housing 3 is connected to the power supply terminal, the bridge output terminal, the ground terminal, and the gate terminal of the semiconductor switching element 2 by laser welding.

  Each conductive plate 6 a is formed with a press-fit terminal portion 6 p, and the press-fit terminal portion 6 p is press-fitted into the through hole 4 a of the circuit board 4, and the wiring pattern of each terminal of the semiconductor switching element 2 and the circuit board 4. And are electrically connected.

  These conductive plates 6a extend in the lead-out direction of each terminal of the semiconductor switching element 2 and are arranged so as to overlap each other. Further, the terminals of the semiconductor switching element 2 are arranged on the surface of the conductive plate 6a facing the heat sink 5. The terminals of the semiconductor switching element 2 are formed with a width of 0.8 mm, a thickness of 0.5 mm, and a terminal interval of 1.7 mm.

Further, a large current flows through the conductive plates 6a connected to the power supply terminal , the bridge output terminal, and the ground terminal, which are large current terminals of the semiconductor switching element 2, respectively. Since the conductive plate 6a is formed of a rolled copper alloy, when the roll surface (front surface) of the conductive plate 6a and the large current terminal of the semiconductor switching element 2 are welded, the conductive plate 6a is connected to the large current terminal. The conductive plate 6a needs to be thick. However, it is difficult to increase the thickness from the viewpoint of forming the press-fit terminal portion and pressing.

  Therefore, in the first embodiment, the plate thickness of the conductive plate 6a is set to 0.8 mm, which is the same as the width of the terminal of the semiconductor switching element 2. Instead, the plate width is formed wider than the plate thickness, and the end surface perpendicular to the roll surface and the terminal of the semiconductor switching element 2 are welded.

That is, the conductive plate 6a is formed such that the dimension in the joining direction with the terminal of the semiconductor switching element 2 is larger than the dimension in the direction perpendicular to the joining direction (width direction).
Since a small current flows through the conductive plate 6a used for signals, there is no need to consider the reduction in electrical resistance. However, the conductive plate 6a is also formed of the same plate material as the conductive plate 6a through which a large current flows.

  The conductive plate 6a is made of a high-strength, high-conductivity copper alloy or phosphor bronze in consideration of the conductivity for passing a large current and the mechanical strength for forming the press-fit terminal portion 6p. In the conductive plate 6a using phosphor bronze, the motor current is used at a current of 30 A or less, for example.

  Also, each terminal of the semiconductor switching element 2 is bent into the same crank-like shape standing and lying down at two locations in the middle part and led out in the same direction. The first bent portion 2a, which is a bent portion on the tip side of each terminal of the semiconductor switching element 2, is formed at an acute angle. The second bent portion 2b, which is a bent portion on the main body side of the semiconductor switching element 2, is formed to stand at a right angle.

As shown in FIG. 2, a heat spreader hs, which is a heat radiating part of the semiconductor switching element 2, is mounted on the upper surface of the thick part of the heat sink 5 that has a thicker intermediate part than both sides. On the other hand, a welded portion of the bent terminal of the semiconductor switching element 2 is arranged above the thin portion on one side of the heat sink 5.
The welding portion of the terminal of the semiconductor switching element 2 to be welded to the conductive plate 6a is separated from the heat spreader hs, and since the heat sink 5 is not attached at the time of welding, the main body of the semiconductor switching element 2 is not subjected to laser welding. There is no obstacle.

The laser LB is irradiated from the direction in which the heat sink 5 is attached toward the surface of the terminal of the semiconductor switching element 2. Thereby, the terminal of the semiconductor switching element 2 is laser-welded to the conductive plate 6a.
Each terminal of the semiconductor switching element 2 has a first bent portion 2a formed at an acute angle and is pressed against the conductive plate 6a by a bending elastic force. The laser LB is irradiated and welded in the vicinity of the tip of each terminal of the semiconductor switching element 2.
At this time, the gap between each terminal of the semiconductor switching element 2 and the conductive plate 6a is expanded from the tip portion toward the first bent portion 2a. As a result, the vicinity of the tip, which is the vicinity of the weld, is configured to be pressed against the conductive plate 6a by the bending elastic force.

  As shown in FIG. 2, a positioning portion 3 h for positioning the semiconductor switching element 2 and the housing 3 is formed in the housing 3. The positioning portion 3h is tapered at the tip. Then, the positioning portion 3h is inserted by being guided by the hole 2c formed in the heat spreader hs of the semiconductor switching element 2 by this taper portion, and positioning is performed. The positioning unit 3h also serves to position each terminal of the semiconductor switching element 2 in the lead-out direction.

Further, as shown in FIG. 1, a pair of positioning portions 3k for positioning each terminal of the semiconductor switching element 2 and the conductive plate 6a is formed facing the housing 3 in a similar manner. The positioning portion 3k performs positioning in a direction perpendicular to the lead-out direction of each terminal of the semiconductor switching element 2.
The positioning part 3k is formed on both outer sides of the terminal of each semiconductor switching element 2, and the tip part is tapered. The taper portion guides the outside of each terminal of the semiconductor switching element 2, thereby positioning the terminals of the semiconductor switching element 2 and the conductive plate 6 a.
Each terminal of the semiconductor switching element 2 positioned by the positioning portions 3h and 3k is welded to the conductive plate 6a.

Further, each terminal of the semiconductor switching element 2 is disposed in the horizontal direction away from the axis AX shown in FIG. 2, which is the press-fit direction of the press-fit terminal portion 6p, and is welded to the conductive plate 6a.
Further, an insulating resin 3a is interposed between the conductive plate 6a on the extension of the axis AX and the heat sink 5. Thereby, the pressure input when press-fitting the press-fit terminal portion 6p into the through hole 4a of the circuit board 4 is received by the heat sink 5 through the insulating resin 3a.
Therefore, the welded part at the time of laser welding is separated from the insulating resin 3a that hinders welding, and the press-fit terminal portion 6p is interposed between the conductive plate 6a and the heat sink 5 when the press-fit terminal portion 6p is press-fitted into the through hole 4a. Since the insulating resin 3a is interposed, laser welding and press-fitting of the through hole 4a can be employed.

By irradiating the laser LB toward the surface of the terminal of the semiconductor switching element 2, the terminal of the semiconductor switching element 2 is connected to the conductive plate 6a. Therefore, it is necessary to prevent the insulating resin 3a from being deteriorated or melted by heat generated by laser welding.
Further, during laser welding, the insulating resin 3a in the vicinity of the laser welded portion is deteriorated or melted by the reflected light of the laser LB generated from the surface of the terminal of the semiconductor switching element 2, and the press-fit terminal portion of the conductive plate 6a. It is necessary to prevent 6p from deteriorating.
Further, during laser welding, the gas generated from the melted portion of the terminal of the semiconductor switching element 2 and the gas generated from the insulating resin 3a in the vicinity of the laser welded portion due to the heat of laser welding, reflected light, etc. It is necessary to prevent adhesion to the press-fit terminal portion 6p.

In the first embodiment, the base end portion of each conductive plate 6 a that is welded to the terminal of the semiconductor switching element 2 is formed to be exposed from the insulating resin 3 a of the housing 3 in the shape of a comb. Thereby, the influence of the heat | fever and reflected light which generate | occur | produce at the time of laser welding with respect to the insulating resin 3a can be decreased.
Further, the press-fit terminal portion 6p of the conductive plate 6a is disposed on the cover 7 side, and the laser welding portion is disposed on the heat sink 5 side. Thereby, the distance of the press fit terminal part 6p and a laser welding part becomes long. As a result, it is possible to reduce the influence of heat, reflected light, and gas generated during laser welding on the press-fit terminal portion 6p.
Further, an insulating resin 3a is interposed between the press-fit terminal portion 6p and the laser welded portion. Thereby, the reflected light generated at the time of laser welding can be made difficult to reach the press-fit terminal portion 6p.

Two press-fit terminals 6p are formed on the conductive plate 6a through which a large current flows, and one press-fit terminal 6p is formed on each conductive plate 6a through which a small signal current flows. That is, as shown in FIG. 1, seven press-fit terminal portions 6p are arranged for one semiconductor switching element 2.
The distance between the terminals of the semiconductor switching element 2 is 1.7 mm as described above. Moreover, the hole diameter of the through hole 4a of the circuit board 4 into which the press-fit terminal portion 6p is press-fitted is formed to be 1.45 mm.
In the first embodiment, the press-fit terminal portions 6p of the adjacent conductive plates 6a are arranged in a staggered manner. Thereby, the distance between the adjacent press fit terminal parts 6p is made longer than the distance between the terminals of the semiconductor switching element 2.

As shown in FIG. 4, the end 15a of the terminal 15 is bent at a right angle and overlapped with the signal connector terminal 8b and the ends 8c and 10b of the sensor connector terminal 10a. This mating surface is formed in parallel with the heat sink 5 and is welded.
At this time, the end portions 8c and 10b of the signal connector terminal 8b and the sensor connector terminal 10a are disposed on the heat sink 5 side. Further, similarly to the welding of the terminal of the semiconductor switching element 2 and the conductive plate 6a, the laser is directed from the direction in which the heat sink 5 is attached toward the surface of the end portion 8c of the signal connector terminal 8b and the end portion 10b of the sensor connector terminal 10a. By irradiation, the signal connector terminal 8b and the sensor connector terminal 10a are welded to the terminal 15, respectively.

Moreover, the terminal 15 has a press-fit terminal portion 15p formed at the end opposite to the welded portion. The press-fit terminal portion 15p is press-fitted into the through hole 4a of the circuit board 4. As a result, the signal connector terminal 8b and the sensor connector terminal 10a connected to the terminal 15 are electrically connected to the wiring pattern of the circuit board 4.
Similar to the conductive plate 6a, the press-fit terminal portion 15p of the terminal 15 is disposed on the cover 7 side, and the laser welded portion is disposed on the heat sink 5 side. Thereby, the distance of the press fit terminal part 15p and a laser welding part becomes long. As a result, it is possible to reduce the influence of heat, reflected light and gas generated during laser welding on the press-fit terminal portion 15p.

The conductive plate 6a to which the bridge output terminal of the semiconductor switching element 2 is connected is connected to the motor connector terminal 9a at the end opposite to the base end. And the motor connector terminal 9a is arrange | positioned in the surface facing the heat sink 5 of the edge part of the electrically conductive board 6a.
The laser LB is emitted toward the direction the heat sink 5 is attached to the surface of the motor connector terminals 9a, in the same way as bridge output terminal of the conductive plates 6a and the semiconductor switching element 2 and is welded, the motor connector terminals 9a Is welded to the conductive plate 6a.

  The motor current output from the bridge output terminal of the semiconductor switching element 2 flows directly to the electric motor (not shown) via the motor connector terminal 9a without passing through the circuit board 4. In addition, a press-fit terminal portion 6 p extending toward the circuit board 4 is formed in an intermediate portion of the conductive plate 6 a connected to the bridge output terminal of the semiconductor switching element 2. As a result, a signal for monitoring the voltage of the motor connector terminal 9 a is output to the circuit board 4.

The conductive plate 6b is connected to a power connector terminal 8a as shown in FIG. The power connector terminal 8a is disposed on a surface facing the heat sink 5 at the end of the conductive plate 6b. Similarly to the case where the laser LB is irradiated toward the surface of the power connector terminal 8a from the direction in which the heat sink 5 is attached and the conductive plate 6a and the motor connector terminal 9a are connected, the power connector terminal 8a It is welded to 6b.
A press-fit terminal portion 6p extending toward the circuit board 4 is formed on the conductive plate 6b. The press-fit terminal portion 6p is press-fitted into the through hole 4a of the circuit board 4. Thereby, the conductive plate 6b and the wiring pattern of the circuit board 4 are electrically connected. And the electric current of the battery of a vehicle is supplied to the circuit board 4 via the power supply connector terminal 8a, the electrically conductive board 6b, and the press fit terminal part 6p.

The circuit board 4 is mechanically held by press-fit terminal portions 6p, 15p, and Hp being press-fitted into the respective through holes 4a.
The conductive plates 6 a and 6 b, the terminal 15, and the holding member H are insert-molded in the insulating resin 3 a of the housing 3. When the press-fit terminal portions 6p, 15p, and Hp are press-fitted, the insulating resin 3a is interposed between the conductive plates 6a and 6b, the terminals 15, the holding member H, and the heat sink 5, so that the pressure input is applied to the heat sink 5 It can be received at.
However, a slight gap is generated between the insulating resin 3a and the heat sink 5 due to manufacturing accuracy.
In press-fit press-fitting, the relative height accuracy between the press-fit terminal portions 6p, 15p, Hp and the circuit board 4 is important. However, since a slight gap is generated between the insulating resin 3a and the heat sink 5, this relative height accuracy is deteriorated.
Therefore, for example, in FIG. 2, adhesives (see FIG. 2) are formed in the gap between the insulating resin 3a below the conductive plate 6a and the heat sink 5, and in the gap between the insulating resin 3a below the conductive plate 6b and the heat sink 5, respectively. (Not shown) is applied to eliminate the influence of this gap.

As shown in FIG. 5, a holding portion 7 d is formed on the inner periphery of the fitting portion 7 c of the cover 7. A holding portion 3m is formed inside the locking hole 3c of the housing 3. The circuit board 4 is sandwiched and held between the holding portion 7d and the holding portion 3m.
The holding part 7d and the holding part 3m are formed at positions where the press-fit terminal parts 6p, 15p and Hp are not arranged, and the press-fit terminal parts 6p, 15p and Hp, the holding part 7d and the holding part 3m The substrate 4 may be mechanically held.

Next, an assembly procedure of the electronic control device 1 configured as described above will be described.
First, cream solder is applied on the circuit board 4, and components such as the microcomputer 13 and its peripheral circuit elements are arranged. Thereafter, using a reflow device, the cream solder is melted and each component is soldered.

Next, the terminal of the semiconductor switching element 2 is bent in a crank shape, and the semiconductor switching element 2 is disposed on the housing 3 with the opening on the attachment side of the heat sink 5 facing upward. At that time, the main body and the terminals of the semiconductor switching element 2 are guided and positioned by the positioning portions 3h and 3k, and the terminals are superimposed on the conductive plate 6a.
Thereafter, the laser LB is irradiated from the terminal side of the semiconductor switching element 2, and each terminal and the conductive plate 6a are laser-welded.
Similarly, the laser LB is irradiated from the power connector terminal 8a and the motor connector terminal 9a side, and the power connector terminal 8a and the conductive plate 6b, and the motor connector terminal 9a and the conductive plate 6a are laser welded respectively.
Further, laser is irradiated toward the surface of the end 8c of the signal connector terminal 8b and the end 10b of the sensor connector terminal 10a, and the signal connector terminal 8b, the sensor connector terminal 10a and the terminal 15 are laser welded respectively.

  Next, an adhesive resin (not shown) with high thermal conductivity is printed thinly on the portion of the heat sink 5 where the semiconductor switching element 2 is mounted. Further, an adhesive (not shown) is applied to the heat sink 5 at a portion facing the insulating resin 3a in the vicinity where the conductive plates 6a and 6b, the terminal 15, and the holding member H are inserted.

Thereafter, the laser welded housing 3 is inverted and placed on the heat sink 5 so that the opening to which the heat sink 5 is attached is down. Further, the locking portion 21 b is press-fitted inside the holding portion 3 g to lock the leaf spring 21 to the housing 3. At the same time, the slit 21c is press-fitted into the holding member H.
Next, the leaf spring 21 is fixed to the heat sink 5 together with the housing 3 using the screw 20, and the semiconductor switching element 2 is pressed against the heat sink 5 by the pressing portion 21 a of the leaf spring 21. Thereafter, the adhesive resin and the adhesive are cured in a furnace maintained at a high temperature.

Next, the end portions of the press-fit terminal portions 6 p, 15 p, and Hp are inserted into the through holes 4 a of the circuit board 4, and the circuit board 4 is mounted on the upper portion of the housing 3. Thereafter, press-fit terminal portions 6p, 15p, and Hp are press-fitted into the respective through holes 4a using a press machine.
Next, the locking projection 7 a of the cover 7 is inserted into the locking hole 3 c of the housing 3, and the cover 7 is disposed in the opening of the housing 3.
Thereafter, the cover 7 is pressed to lock the cover 7 to the housing 3, and the assembly of the electronic control device 1 is completed.

  As described above, according to the electronic control device 1 of this embodiment, the attachment means for attaching the cover 7 to the housing 3 includes the locking projection 7a formed on the cover 7 and the engagement formed on the housing 3. Since the locking projection 7a is inserted into the locking hole 3c and the cover 7 is attached to the housing 3, the assembling workability of the electronic control device 1 is improved. .

  Moreover, since the cover 7 and the locking projection 7a are integrally formed of an insulating resin, the electronic control device 1 is reduced in weight.

Further, a flange portion 7b is formed at the end of the locking projection 7a, and a convex portion 3d for locking the flange portion 7b of the locking projection 7a is formed on the inner wall surface of the locking hole 3c. As the locking projection 7a is inserted, the tapered portion 3e for elastically deforming the flange portion 7b is formed, so that the locking projection 7a can be easily inserted, and the electronic control device 1 is assembled. Improves.
Further, the cover 7 is securely locked to the housing 3, and the dust resistance of the electronic control device 1 is improved.

Also, the locking projections 7a are paired and project in the vertical direction, and the flanges 7b are formed in directions opposite to each other, and inside the locking hole 3c. Since the convex portions 3d and the tapered portions 3e are formed on the opposing inner wall surfaces, the insertion of the locking projections 7a is facilitated, and the workability of assembling the electronic control device 1 is improved.
Further, the cover 7 is securely attached to the housing 3, and the dust resistance of the electronic control device 1 is improved.

In addition, since the locking hole 3c is integrally formed with an insulating resin on the inner wall surface of the side wall 3b of the housing 3, the electronic control device 1 can be reduced in size.
Further, the attachment means for attaching the cover 7 to the housing 3 cannot be seen from the outside, and it is difficult to easily remove the cover 7 from the housing 3, thereby preventing illegal modification of the internal structure.

  Further, when the locking projection 7a is inserted into the locking hole 3c, the flange portion 7b is elastically deformed in a direction parallel to the side wall 3b of the housing 3 by the tapered portion 3e. Thus, the protrusion of the mounting means is reduced, and the electronic control device 1 can be miniaturized.

  Further, a fitting portion 7c is formed at the base portion of the locking projection 7a, and the fitting portion 7c is fitted into the insertion port 3f of the locking hole 3c so that the cover 7 and the housing 3 are positioned. Therefore, the external force applied to the cover 7 does not damage the locking projection 7a due to excessive stress, and the dust resistance of the electronic control device 1 is improved.

  Further, since the flange portion 7b of the locking projection 7a is formed so as to be directed in the opposite directions, the locking hole 3c can be formed small, and the electronic control device 1 can be miniaturized.

Further, since the locking projections 7a are formed in pairs on each side of the cover 7, the cover 7 is securely locked to the housing 3, and the dust resistance of the electronic control device 1 is improved.
Further, abnormal noise generated on the mating surface of the cover 7 and the housing 3 is suppressed by vibration or the like.

  Further, since the locking projections 7a arranged on the opposite sides are arranged point-symmetrically with respect to the center of the plane parallel to the circuit board 4, the cover 7 can be attached at a position rotated by 180 °. This improves the workability of assembling the electronic control unit 1.

In addition, the locking hole 3c is disposed opposite to the insertion port 3f so that the heat sink 5 is opposed to the locking hole 3c, and the locking hole 3c is closed by the heat sink 5. Intrusion is prevented and the dustproofness of the device is improved.
In addition, illegal modification can be prevented.

  Further, since the circuit board 4 is sandwiched and held between the holding portion 7d formed on the cover 7 and the holding portion 3m formed on the housing 3, vibration of the circuit board 4 is suppressed, and the electronic control device The vibration resistance of 1 is improved.

  Further, since the holding portion 7d is formed inside the peripheral edge of the fitting portion 7c of the cover 7 and the holding portion 3m is formed inside the locking hole 3c of the housing 3, the circuit board 4 is firmly held, The vibration resistance of the electronic control device 1 is improved.

Embodiment 2. FIG.
FIG. 7 is a cross-sectional view showing the main part of the electronic control unit 1 according to Embodiment 2 of the present invention.
In this figure, the electronic control device 1 is being assembled, and the heat sink 5 is on the upper side of the cover 7.
In this embodiment, the configuration is the same as that of the electronic control device 1 of the first embodiment except for the configuration of the housing 3 and the cover 7.
In other words, in this embodiment, the groove 7e, which is the first groove, is formed along the entire circumference of the outer peripheral edge of the cover 7. The groove 7e is open on the housing 3 side. At the opening end of the housing 3 on the cover 7 side, a protrusion 3n is formed along the entire circumference. A space formed in a state where the projection 3n enters the groove 7e is filled with a silicon adhesive 31 which is an adhesive resin.
The locking projection 7a of the cover 7 is formed inside the groove 7e. The locking projection 7 a is inserted into the locking hole 3 c of the housing 3, and the cover 7 is attached to the housing 3.

A groove 30 as a second groove is formed between the outer peripheral end surface of the heat sink 5 and the inner wall surface 3 p of the opening of the housing 3. The groove 30 is filled with the same silicon adhesive 31 as the adhesive filled in the groove 7e.
The groove 7e and the groove 30 are open in the same direction. Then, the silicon adhesive 31 is filled from the same direction.
Although not shown, the housing 3 is provided with a breathing hole that allows the inside and outside of the electronic control unit 1 to communicate with each other, and a water repellent filter that allows air to pass but does not allow water to pass through is attached to the breathing hole. .

The assembly procedure of the electronic control device 1 according to this embodiment is the same as that of the first embodiment until the step of press-fitting the press-fit terminal portions 6p, 15p, Hp into the through holes 4a of the circuit board 4 using a press machine. It is.
Next, a water repellent filter (not shown) is attached to a breathing hole (not shown) formed in the housing 3 by heat welding.

Thereafter, as shown in FIG. 7, the cover 7 is set with the opening side of the groove 7e facing up, and the groove 7e is filled with the silicon adhesive 31.
Next, the locking protrusion 7 a of the cover 7 is inserted into the locking hole 3 c of the housing 3 with the mounting surface of the cover 7 facing down. Thereafter, the housing 3 is pressed to attach the cover 7 to the housing 3.

Thereafter, the silicon adhesive 31 is filled into the groove 30 with the opening of the housing 3 facing upward. Next, in a state where both the groove 7e and the groove 30 are on the top, the electronic control device 1 is put in a high-temperature furnace, and the silicon adhesive 31 is cured.
After the silicon adhesive 31 is cured, the electronic control device 1 is taken out of the furnace and cooled, and the assembly of the electronic control device 1 is completed.
The silicon adhesive 31 may be a room temperature curing adhesive.
The breathing hole may be provided in the cover 7 and a water repellent filter may be attached to the breathing hole.
A water repellent filter may be attached after the step of curing the silicon adhesive 31.

According to the electronic control device 1 of the second embodiment, the groove 7e is formed in the outer peripheral edge portion of the cover 7, and between the outer peripheral end surface of the heat sink 5 and the inner wall surface 3p of the opening portion of the housing 3, Grooves 30 are formed, and these grooves 7e and 30 are filled with a silicon adhesive 31.
As a result, the inside of the electronic control device 1 is sealed with respect to the outside, water can be prevented from entering the inside of the electronic control device 1 from the outside, and the waterproofness of the electronic control device 1 is improved.

In addition, a locking projection 7a and a locking hole 3c constituting an attachment means are arranged inside the groove 7e.
As a result, the attachment means is not damaged by an external force, and the waterproofness of the electronic control device 1 is improved.

Further, since the grooves 7e and 30 open upward in the same direction and are filled with the silicon adhesive 31 from the same direction, the silicon adhesive flows out of the grooves 7e and 30 during the curing of the silicon adhesive 31. There is nothing.
As a result, the assembling workability of the electronic control device 1 is improved and the waterproofness is improved.

In the first and second embodiments, each terminal of the semiconductor switching element 2 and the conductive plate 6a are joined by laser welding, but other welding methods such as resistance welding and TIG welding may be used.
Moreover, ultrasonic bonding other than welding may be used.

Further, the semiconductor switching element 2 is configured such that a half bridge in which a high-side MOSFET and a low-side MOSFET are integrated is housed in one package and a bridge circuit for switching the current of the electric motor as a set of two. However, the high-side MOSFET and the low-side MOSFET may be configured separately, and a bridge circuit may be configured by the four semiconductor switching elements 2.
Alternatively, a configuration may be adopted in which a bridge circuit is configured with six semiconductor switching elements 2 to drive and control a three-phase brushless motor.
Moreover, although the power device is the semiconductor switching element 2, other power devices such as a diode and a thyristor may be used.

  Further, although the plate thickness of the conductive plate 6a is 0.8 mm, the plate thickness is set to 1.0 mm, 1.2 mm, etc. in consideration of the current flowing through the conductive plate 6a, the distance between the terminals of the semiconductor switching element 2, and the like It is good also as board thickness.

  Moreover, the example applied to the electric power steering apparatus of a motor vehicle was demonstrated. However, the present invention can be applied to an electronic control device that handles a large current (for example, 25 A or more) equipped with a power device, such as an electronic control device for an anti-lock brake system (ABS) or an electronic control device for air conditioning. The same effect can be obtained.

  DESCRIPTION OF SYMBOLS 1 Electronic control apparatus, 2 Semiconductor switching element (power device), 3 Housing, 3c Locking hole, 3d Convex part, 3e Tapered part, 3f Insertion port, 3m Holding part, 3n Protrusion, 4 Circuit board, 5 Heat sink, 7 Cover, 7a Locking projection, 7b Hook, 7c Fitting, 7d Holding part, 7e Groove (first groove), 30 Groove (second groove), 31 Silicone adhesive (adhesive resin).

Claims (11)

A housing made of insulating resin having openings at both ends,
A heat sink attached to one end of the housing 3;
Power device mounted on this heat sink,
A circuit board on which an electronic circuit including a control circuit for controlling the power device is formed and provided facing the heat sink;
A cover made of an insulating resin that is attached to the other end of the housing and stores the power device and the circuit board in cooperation with the heat sink;
An electronic control device comprising attachment means for attaching the cover to the housing,
The attachment means includes a locking projection formed in the cover and a locking hole formed in the housing, and the locking projection is inserted and locked into the locking hole. The cover is attached to the housing ;
The electronic control device according to claim 1, wherein the cover is positioned with respect to the housing by fitting a base portion of the locking projection into an insertion port of the locking hole .   The electronic control device according to claim 1, wherein an end of the locking protrusion is formed in a hook shape.   On the inner wall surface of the locking hole, a convex portion for locking the end portion of the hook shape, and the end portion of the hook shape in the middle of the insertion of the locking projection toward the convex portion. The electronic control device according to claim 2, wherein a tapered portion that is gradually elastically deformed is formed.   The electronic control device according to any one of claims 1 to 3, wherein two of the locking protrusions are integrally inserted into the locking hole and locked.   The electronic control device according to claim 1, wherein the locking hole is formed inside the housing.   The electronic control device according to claim 5, wherein the locking hole is formed on an inner wall surface of a side wall of the housing.   The said latching protrusion is elastically deformed along the side wall of the said housing, is inserted in the said latching hole, and is latched. Electronic control unit. It said locking hole, the electronic control device according to any one of claim 1 to 7, characterized in that it is formed opposite to the heat sink. The circuit board, the electronic control device according to any one of claims 1-8, characterized in that it is held sandwiched between the said cover and the housing. A first groove is formed between the housing and the cover, a second groove is formed between the housing and the heat sink, and the attachment means is disposed inside the first groove. together provided, the electronic control device according to any one of claim 1 to 9, these first groove and a second groove in the adhesive resin is characterized in that it is filled. 11. The electron according to claim 10 , wherein the first groove portion is formed in a peripheral portion of the cover, and the first groove portion and the second groove portion are formed with openings in the same direction. Control device.

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