JP2021019132A - Method of removing circuit board - Google Patents

Abstract

To provide a technology that can stably remove a circuit substrate from a case even if the circuit substrate has less than 4 notches for hooking.SOLUTION: In a power control device 100, a circuit board 10 is housed in a case 2 with a flat surface facing upward. The circuit board 10 is provided with less than 4 notches 16. A connector 14, including one or more hook locking portions, is attached to the flat surface facing upward. In this removal method, a hook 32 is hooked at a total of four places of the notches 16 and the hook locking portions and pulled up.SELECTED DRAWING: Figure 3

Description

The technology disclosed herein relates to a method of removing a circuit board housed in a case of an electrical device.

Circuit boards are often housed in cases in electrical equipment. Patent Document 1 discloses an electric device (electronic control device) in which a circuit board is housed in a case with the plane facing upward. The circuit board may be removed from the case for maintenance of electrical equipment. Patent Document 1 also discloses a jig for removing the circuit board from the case. The circuit board is provided with notches at four edges so as to surround the center thereof, and the jig pulls up the circuit board (removes it from the case) by hooking hooks at the four notches.

Japanese Unexamined Patent Publication No. 2016-192493

If the number of components mounted on the circuit board increases, it may not be possible to provide notches at four appropriate positions on the circuit board. If there are less than four places where the hooks of the jig are hooked, the balance may be lost during pulling up. If a connector is provided on the underside of the circuit board and the connector is mated with the terminal of another component, the force of pulling up the circuit board must pull the terminal of the other component out of the connector on the underside. In such a case, when pulling up the circuit board, a biased force may be applied to the circuit board, and if you try to pull up the circuit board by hooking hooks at less than four positions, the balance may be lost as described above. , The circuit board may be deformed. The present specification provides a technique capable of stably removing a circuit board having less than four notches for hooking hooks from the case.

This specification discloses a method of removing a circuit board housed in a case of an electric device. The circuit board is housed in the case with the plane facing up. The circuit board is provided with less than four notches, and a connector with one or more hook locking portions is attached to an upwardly facing plane. In the removal method disclosed in the present specification, the hook is hooked and pulled up at a total of four places of the notch and the hook locking portion. That is, in the removal method disclosed in the present specification, the connector attached to the circuit board is provided with a hook hooking portion (hook locking portion), so that the notch provided in the circuit board itself (to hook the hook) is provided. Even if there are less than four notches), the circuit board can be pulled up stably.

Details of the techniques disclosed herein and further improvements will be described in the "Modes for Carrying Out the Invention" below.

It is a perspective view of the electric power control apparatus which adopts the removal method of an Example. It is a top view of the power control apparatus which adopts the removal method of an Example. It is a perspective view explaining the removal method of an Example (1). It is a perspective view explaining the removal method of an Example (2). It is a partial cross-sectional view along the straight line VV of FIG.

A method of removing the circuit board in the embodiment will be described with reference to the drawings. A power control device 100 including a circuit board 10 to be removed by the removal method of the embodiment will be described with reference to FIG. The electric power control device 100 is, for example, an inverter for a traveling motor of an electric vehicle. The power control device 100 includes a case 2, a circuit board 10, and a case cover (not shown). The upper side of the case 2 is open. The case 2 houses a plurality of electronic components such as a reactor (not shown) under the circuit board 10. A plurality of electronic components are arranged on the bottom of the case 2 from the open portion on the upper side of the case 2, and then the circuit board 10 is arranged from above and covered with a case cover (not shown) to complete the power control device 100. The circuit board 10 is housed in the case 2 of the power control device 100. In the following, a plurality of electronic components (not shown) housed under the circuit board 10 may be referred to as in-case electronic components.

As shown in FIG. 1, a flange is provided on the entire circumference of the opening of the case 2. The flange of the case 2 is provided with six bolt holes 4. The case cover is fixed to the case 2 by screwing a bolt penetrating the case cover (not shown) arranged in the case 2 into the bolt hole 4.

The circuit board 10 will be described. The circuit board 10 controls the electronic components in the case by using the mounted circuit. The circuit board 10 connects the electronic components in the case and the peripheral components of the power control device 100. The circuit board 10 includes a semiconductor chip group 12 and a connector 14. The semiconductor chip group 12 is electrically connected to the electronic components in the case below the circuit board 10. Although not shown, many devices other than the semiconductor chip group 12 are mounted on the circuit board 10. The semiconductor chip group 12 and a large number of devices (not shown) form a circuit for controlling electronic components in the case.

The connector 14 electrically connects the electronic components in the case of the power control device 100 and the peripheral components of the power control device 100. The input from the peripheral parts of the power control device 100 is sent to the electronic parts in the case via the connector 14. The output of the electronic component in the case is sent to the peripheral component via the connector 14. The circuit board 10 is fixed to the case 2 by a plurality of bolts 6. The case 2 is provided with a positioning pin 8 at the edge on the negative side in the X-axis direction. By fitting the positioning pin 8 into the circuit board 10, the displacement of the circuit board 10 with respect to the opening of the case 2 is suppressed.

The shape of the circuit board 10 will be further described with reference to FIG. FIG. 2 is a plan view of the power control device 100 with the case cover removed. The circuit board 10 has a rectangular shape extending in the X-axis direction. As described above, the circuit board 10 is connected to the electronic component in the case below the circuit board 10. A semiconductor chip group 12, a connector 14, and a large number of devices (not shown) are arranged on a plane facing upward of the circuit board 10. The circuit board 10 is housed in the case 2 with the plane facing up. Further, the circuit board 10 is loosely fitted in the case 2. The outer circumference of the circuit board 10 is surrounded by the inner surface of the case 2. There is only a small gap between the outer circumference of the circuit board 10 and the inner surface of the case 2.

Here, the maintenance of the power control device 100 will be described. When maintaining the power control device 100, the operator removes a case cover (not shown) of the power control device 100. After that, the operator removes the circuit board 10 and performs maintenance on the power control device 100. As described above, since there is only a small gap between the outer circumference of the circuit board 10 and the inner surface of the case 2, there is a space for inserting the operator's finger or the jig for removing the circuit board 10. Does not exist. Further, as described above, since the circuit board 10 is housed in the case 2 with the plane facing upward, there is no portion to be gripped when the circuit board 10 is removed.

As shown in FIG. 2, the circuit board 10 is provided with two notches 16 on the negative side in the Y-axis direction and one notch 16 on the positive side in the Y-axis direction. That is, the circuit board 10 is provided with three notches 16. The notch 16 is formed by cutting a part of the edge of the circuit board 10 into a rectangular shape. Although the details will be described later, at the time of maintenance of the power control device 100, the hook of the jig is hooked on the notch 16 and the circuit board 10 is pulled up. As described above, on the surface of the circuit board 10, in addition to the semiconductor chip group 12 and the connector 14, a large number of devices (not shown) are mounted. In the circuit board 10, a notch 16 cannot be provided at a portion where a device such as a semiconductor chip group 12 is mounted. Due to the convenience of device mounting, the circuit board 10 cannot be provided with four notches, and only three notches 16 are provided.

As described above, below the circuit board 10, the semiconductor chip group 12 and the electronic components in the case are connected. The semiconductor chip group 12 and the electronic component in the case are connected by fitting a plurality of terminals. Therefore, a frictional force is generated at the fitting portion of the terminals of the semiconductor chip group 12 of the circuit board 10 while the circuit board 10 is being pulled up. Further, as described above, the positioning pin 8 of the case 2 is fitted in the circuit board 10. A frictional force is generated at a portion where the positioning pin 8 of the circuit board 10 is fitted while the circuit board 10 is being pulled up.

It is possible to pull up the circuit board 10 by hooking the hooks on the three notches 16. However, in that case, if an unbalanced frictional force is applied to the circuit board 10 by the terminals of the semiconductor chip group 12 or the positioning pin 8, the balance may be lost or the circuit board 10 may be deformed while the circuit board 10 is being pulled up. Can occur. Hereinafter, a method of removing the circuit board 10 having only three notches 16 for hooking the hooks from the case 2 in a well-balanced manner will be described.

A method of removing the circuit board 10 will be described with reference to FIG. FIG. 3 shows a state before the jig 20 is attached to the case 2. After removing the case cover of the power control device 100, the jig 20 is attached to the case 2 from above. Two guide pins 34 are fixed to the bolt holes 4 at the end of one side of the case 2 on the positive side in the Y-axis direction. The jig 20 includes an opening 22, a first guide portion 24, a second guide portion 25, a through hole 26, and an accommodating portion 28. The first guide portion 24 has a hollow cylindrical shape. The second guide portion 25 is a hole that penetrates the jig 20 in the Z-axis direction. The first guide portion 24 and the second guide portion 25 are provided at positions facing each of the two guide pins 34 fixed to the case 2.

The jig 20 further includes three support portions 30a and one support portion 30b. The support portion 30a and the support portion 30b have the same shape. The functions of the support portions 30a and 30b will be described in detail later, but the support portion for locking the notch 16 of the circuit board 10 is represented by reference numeral 30a, and the support for locking the hook locking portion (described later) provided in the connector 14. The part is represented by reference numeral 30b. In the following, when the support portion 30a and the support portion 30b are represented without distinction, they are referred to as the support portion 30.

The support portion 30 includes a lever portion located at the upper end portion of the support portion 30 and a hook 32 located at the lower end portion. The lever portion of the support portion 30 has a cylindrical shape. The hook 32 of the support portion 30 is a rectangle extending in the X-axis direction. The support portion 30 penetrates a rectangular hole provided in the jig 20. As shown in FIG. 3, the rectangular hole of the jig 20 through which the two support portions 30 on the negative side in the Y-axis direction penetrate extends to the negative side in the X-axis direction. The rectangular hole of the jig 20 through which one support portion 30 arranged on the positive side in the Y-axis direction penetrates extends to the positive side in the X-axis direction. The hook 32 extends in the same direction as the rectangular hole of the jig 20 through which each of the hooks 32 penetrates.

Since the lever portion of the support portion 30 has a diameter larger than that of the rectangular hole, it is exposed on the upper surface of the jig 20 without penetrating the rectangular hole of the jig 20. As shown in FIG. 3, the jig 20 includes four support portions 30. When the jig 20 is attached to the case 2, the hooks 32 of the three support portions 30a are inserted into the notches 16 of the circuit board 10.

FIG. 4 shows a state in which the jig 20 is attached to the case 2. Each of the two guide pins 34 is fitted into the first guide portion 24 and the second guide portion 25 of the jig 20. The semiconductor chip group 12 is exposed from the opening 22 of the jig 20. Further, the connector 14 (see FIG. 3) of the circuit board 10 is covered with the accommodating portion 28 of the jig 20. After attaching the jig 20 to the case 2, the maintenance worker moves the lever portion of the support portion 30 along the rectangular hole of the jig 20 in the direction of the arrow shown in FIG. When each of the support portions 30 moves in the direction of the arrow, the hook 32 of the support portion 30a enters below the edges of the three notches 16 of the circuit board 10. Further, as will be described in detail later, the operator also moves the support portion 30b arranged at the edge portion on the negative side in the X-axis direction of the jig 20 in the direction of the arrow. As a result, the hook 32 of the support portion 30b enters below the hook locking portion (described later) provided in the connector 14 (see FIG. 3).

After moving the support portion 30 in the direction of the arrow, the operator removes a plurality of bolts 6 for fixing the circuit board 10 to the case 2. The operator removes the bolt 6 from above the through hole 26 of the jig 20 using a screwdriver or the like.

After removing the plurality of bolts 6, the operator pulls up the jig 20 upward. At this time, the operator pulls up the jig 20 while bringing each of the two guide pins 34 into contact with the inner surfaces of the first guide portion 24 and the second guide portion 25. The circuit board 10 locked to the support portion 30 is pulled up by pulling up the jig 20 while bringing each of the two guide pins 34 into contact with the inner surfaces of the first guide portion 24 and the second guide portion 25. Can be pulled up vertically. By pulling up the circuit board 10 vertically, the terminals of the semiconductor chip group 12 described above can be pulled out vertically. As a result, it is possible to prevent the terminals of the semiconductor chip group 12 from bending. Further, the operator pulls up the jig 20 from the Y-axis positive direction side of the case 2. By providing the two guide pins 34 on the worker side of the case 2, the worker can easily pull up the jig 20 vertically.

The circuit board 10 is provided with notches 16 at which hooks can be locked only at three places. On the other hand, the connector 14 is also provided with a hook locking portion (described later) for locking the hook of the support portion 30b. The circuit board 10 can be lifted by locking hooks at a total of four locations. In particular, the four support portions 30 are arranged so as to surround the center of gravity of the circuit board 10 when viewed from above. The circuit board 10 can be pulled up in a well-balanced manner by locking at four places surrounding the center of gravity.

As described above, in the method of removing the circuit board disclosed in the present specification, the circuit board 10 can be removed in a well-balanced manner even when the notches cannot be provided at the four positions of the circuit board 10.

The details of the structure in which the support portion 30b locks the connector 14 will be described with reference to FIG. Since the structure in which the support portion 30a locks the notch 16 (see FIG. 2) is clear, the description thereof will be omitted. FIG. 5 is a cross-sectional view taken along the straight line VV of FIG. FIG. 5 shows a state in which the circuit board 10 is pulled up after the jig 20 is attached to the case 2. As shown in FIG. 5, a connector 14 is attached to the upper surface of the circuit board 10. Although not shown, the connector 14 is bolted and fixed to the circuit board 10 at a position that does not appear in the cross section of FIG. As shown in FIG. 5, the connector 14 includes a hook locking portion 14f. The hook locking portion 14f extends in the X-axis direction. When the circuit board 10 is removed, the upper surface of the hook 32 of the support portion 30 comes into contact with the lower surface of the hook locking portion 14f. After that, the operator moves the jig 20 upward as shown by the arrow in FIG. Each of the other support portions 30a locks the notch 16. When the jig 20 is pulled upward, the support portions 30a at three locations and the support portions 30b at one location pull up the circuit board 10. As a result, the circuit board 10 can be removed from the case 2.

It is effective to provide a total of four notches and hook locking portions at positions close to the portions where frictional force is generated during pulling up the circuit board and in a well-balanced position to support the entire circuit board.

The connector 14 is taller than the semiconductor chip group 12 mounted on the circuit board 10 and other devices (resistive elements, capacitor elements, switching elements, etc.). In addition, the main body of the connector is often made of resin, and there is a degree of freedom in shape. The technique disclosed in the present specification focuses on such a connector, and decides to provide a hook locking portion 14f on the connector 14 mounted on the circuit board 10.

Further, the hook locking portion 14f of the connector 14 may be a protrusion or a recess provided in the connector. Further, a plurality of connectors having the hook locking portion 14f may be attached to the circuit board 10. In that case, a total of four hook locking portions may be secured by the notches of the hook locking portions 14f of the plurality of connectors and the circuit board 10. For example, it may be a circuit board including one notch and a connector having three hook locking portions. A total of four hooks are arranged so as to surround the center of gravity of the circuit board 10 when the circuit board 10 is viewed in a plan view.

The circuit board 10 to which the removal method of the embodiment is applied is provided with a total of four hook locking portions (three notches 16 and one hook locking portion 14f). The circuit board may be provided with two connectors, the circuit board may be provided with two notches, and each connector may be provided with a hook locking portion. The circuit board targeted by the removal method disclosed in the present specification may be provided with a total of four locking portions having less than four notches and hook locking portions.

Further, in the removal method of the embodiment, the operator moves the support portion 30 in the direction of the arrow shown in FIG. The technique disclosed in the present specification is not limited to this, and the operator may pull up the circuit board 10 by moving the support portion 30 in, for example, the Y-axis direction or the direction opposite to that of the embodiment. .. In that case, the direction of the rectangular hole provided in the jig 20 shown in FIG. 3 and the direction of the hook 32 of the support portion 30 also change in the same direction as the direction in which the support portion 30 is moved.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above. The technical elements described herein or in the drawings exhibit their technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in the present specification or drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

2: Case 4: Bolt hole 6: Bolt 8: Positioning pin 10: Circuit board 12: Semiconductor chip group 14: Connector 14f: Hook locking portion 16: Notch 20: Jig 22: Opening 24: First guide portion 25 : Second guide portion 26: Through hole 28: Accommodating portions 30, 30a, 30b: Support portion 32: Hook 34: Guide pin 100: Power control device

Claims (1)

This is a method for removing the circuit board housed in the case of electrical equipment.
The circuit board is housed in the case with the plane facing up.
The circuit board is provided with less than four notches, and a connector having one or more hook locking portions is attached to the plane.
A method of removing a circuit board, in which hooks are hooked and pulled up at a total of four places, the notch and the hook locking portion.

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