JP2511574B2 - Storage structure for circuit board in case - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board case for mounting a circuit board on which electronic parts are mounted in a case in which an insulating sheet is interposed between the circuit board and the inner peripheral surface of the case. It is related to the storage structure in.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 8, when a circuit board 2 made of a printed board on which an electronic component 3 is mounted is mounted in a metal case 1, a conductive portion of the circuit board 2 and the case are mounted. In general, an insulating sheet 4 made of synthetic resin is interposed between the inner peripheral surface of the case 1 and the circuit board 2 in order to prevent direct contact with the circuit board 2. Further, in order to secure the electrical insulation performance between the conductive portion of the circuit board 2 and the case 1, a spacer is required to dispose the circuit board 2 and the case 1 apart from each other.

A fixing member 11 made of a synthetic resin called a locking support is often used as the spacer.
The fixture 11 is formed by integrally forming an expandable / retractable umbrella-shaped outer holding portion 11b and an inner holding portion 11c facing the outer holding portion 11b at both ends of the shaft portion 11a. Therefore, when the outer holding portion 11b is inserted into the through hole formed in the object, the outer holding portion 11b and the inner holding portion 1 are inserted.
The object is sandwiched between 1c. To use as a spacer between the case 1 and the circuit board 2, a through hole is formed in each of the case 1 and the circuit board 2, and the shaft portion 11 is formed.
If the case 1 and the circuit board 2 are respectively sandwiched between the outer holding portions 11a and the inner holding portions 11b provided at both ends of a, the case 1 and the circuit board 2 are separated by the length of the shaft portion 11a. It can be separated.

As another spacer, as shown in FIG. 9, there is a support base 12 made of an elastic material such as rubber. This support base 12 is fixedly attached to the circuit board 2 at various points,
By being placed on the bottom surface of the case 1, the distance between the case 1 and the circuit board 2 is maintained. A pressing piece 13 formed by cutting and raising is provided at a key portion of the inner peripheral surface of the case 1, and the pressing piece 13 is brought into contact with the peripheral portion of the surface of the circuit board 2 opposite to the support base 12. Thus, the circuit board 2 is prevented from rising from the bottom surface of the case 1.

Further, as shown in FIG. 10, a holding base 14 made of an insulating material such as synthetic resin may be used as a spacer. The holding base 14 includes a base plate 14a that covers the entire back surface of the circuit board 2 and a base plate 14a.
The holding piece 14b is formed integrally with the back surface of the circuit board 2 at a right angle from the peripheral edge of the holding piece 14b. Holding piece 14b
Stands up so as to come into contact with the peripheral edge of the circuit board 2, and a holding claw 14c that holds the peripheral portion of the circuit board 2 between the base 14a and the base plate 14a is provided at a key portion of the holding piece 14b. Therefore, if the circuit board 2 is inserted into a portion surrounded by the holding pieces 14b, the circuit board 2 is mounted on the holding base 14 and the circuit board 2
If the holding base 14 on which is mounted is installed in the case 1, the circuit board 2 can be held and insulated at the same time. Further, mounting claws 14e that engage with the case 1 are provided on the peripheral surface of the base plate 14a in a protruding manner. Here, a groove portion 14d is formed on the base plate 14a in accordance with the leads of the electronic components mounted on the circuit board 2. In addition, in this configuration, the insulating sheet is of course unnecessary.

[0006]

In the configuration of FIG. 8, since the fixing tool 11 such as a locking support is used as a spacer, if the length of the shaft portion 11a is increased, the space between the case 1 and the circuit board 2 will be increased. Insulation performance is ensured, and since the case 1 and the circuit board 2 are only connected by the shaft portion 11a, if the shaft portion 11a is formed flexibly, the circuit will be applied even if an impact force is applied to the case 1. Not transmitted to the board 2,
The damage of the circuit board 2 can be prevented. On the other hand, when the circuit board 2 becomes large, a plurality of fixtures 11 are required,
There is a problem that the cost becomes high and the number of steps required to attach the fixture 11 increases.

In the configuration shown in FIG. 9 as well, if the circuit board 2 becomes large, a plurality of support bases 12 are required, leading to high cost, and there is a problem that the number of steps required for mounting increases.
Further, in the configuration of FIG. 10, since one holding base 14 is provided for one circuit board 2, the number of steps is reduced as compared with the configurations of FIG. 8 and FIG. Since it is necessary to form the groove portion 14d corresponding to the specifications on the base plate 14a, there is a problem that the cost becomes high.

Further, in the configuration shown in FIGS. 9 and 10, the support 12 and the holding base 14 are relatively hard, and the case 1
The impact force on the
When the case 1 is dropped, an impact force is applied to the circuit board 2 and the circuit board 2 may be damaged. The present invention is intended to solve the above problems,
A spacer is provided between the case and the circuit board at a relatively low cost, and the impact force caused by dropping the case, etc. can be mitigated to prevent damage to the circuit board, and the insulation distance between the case and the circuit board can be secured securely. It is a small holding piece
Even if it is possible to prevent the circuit board from rising,
Even changing the relative position between the piece and the step of the insulating sheet
It is possible to deal with circuit boards with different specifications, and it is inexpensive and versatile.
Despite its assembled structure, it is resistant to drops and impacts.
Is intended to provide a storage structure for shock absorption is obtained that the circuit board case with.

[0009]

According to the present invention, in order to achieve the above object, an insulating sheet is interposed between a circuit board on which electronic components are mounted and an inner peripheral surface of a case, and an inner peripheral surface of the case is provided. substantially in storage structure to the circuit board of the case that OsameSo in the case of the circuit board in a manner that is separated a circuit board, an insulating sheet is to be placed is key point of the peripheral portion of the soldering side of the circuit board from Flexibility in shape with L-shaped step
It is made of synthetic resin that
The height of the stepped part is the height of each electronic component mounted on the circuit board.
The length is set longer than the length of the lead wire, and the step
Directly press the upper surface of the peripheral part of the circuit board on the component mounting side.
The holding piece for taking in is cut and raised from the case <br />.

[0010]

According to the above construction, the step portion is formed on the insulating sheet interposed between the inner peripheral surface of the case and the circuit board, and the peripheral portion of the circuit board is placed on the step portion, whereby the case is formed. Since the inner peripheral surface of is separated from the circuit board, it is not necessary to provide another member as a spacer for separating the inner peripheral surface of the case and the circuit board, and it is possible to suppress an increase in cost. In addition, the number of steps for mounting the circuit board in the case is reduced. Further, since the insulating sheet is a thin synthetic resin and has flexibility, the force applied to the circuit board can be mitigated even if an impact force acts on the case due to the case falling or the like. It is possible to prevent the damage of. Here, the step should be approximately L-shaped
In the event of a drop or impact, the insulation properties of the insulation sheet
Impact force is transmitted directly to the periphery of the circuit board placed on the step
Therefore, the circuit board can be prevented from cracking. Also insulation sheet
The height of the step with respect to the bottom of the
Set to a dimension longer than the length of the lead wire of the electronic component
Lead wire of each electronic component
There is no need to worry about piercing, and there is no disconnection between the case bottom and component lead wires.
The edge distance is secured and good insulation can be maintained.
Furthermore, the upper surface of the peripheral part of the circuit board in the step part on the component mounting side
The pressing piece for directly pressing the
Therefore, even if a small holding piece is used,
Lift can be reliably prevented is also of the.

[0011]

Example 1 As shown in FIG. 1, a circuit board 2 made of a printed board in which an electronic component 3 is mounted on a metal case 1 is installed.
An insulating sheet 4 made of thin synthetic resin is interposed between the inner peripheral surface of the case 1 and the circuit board 2. The peripheral portion of the circuit board 2 can be placed on the insulating sheet 4.
A substantially L-shaped step portion 4a is formed. That is, the step 4
The a is formed at two locations so that both sides of the circuit board 2 can be supported (see FIG. 2). Here, if the height H of the step portion 4a is set to be larger than the maximum length of the lead wire of each electronic component 3 mounted on the circuit board 2, the inner peripheral surface of the case 1 and the circuit board 2 are The spaces are separated from each other to maintain the insulation performance. Further, since the circuit board 2 floats up only by mounting the circuit board 2 on the stepped portion 4a, a pressing piece for holding the peripheral portion of the circuit board 2 between the stepped portion 4a and the key portion of the case 1 is provided. 5 is cut and raised. Here, as shown in FIG. 1, the distance between the pressing piece 5 and the step portion 4a is made wider than the thickness of the peripheral portion of the circuit board 2, and the circuit board 2 is arranged almost freely on the insulating sheet 4. As a result, the impact force applied to the case 1 can be sufficiently mitigated, and the circuit board 2 can be prevented from being damaged even when the impact force due to the case 1 being dropped or the like is applied.

It is desirable that the height H and the width W of the step portion 4a of the insulating sheet 4 (see FIG. 3) be set so that H = W. This is because, when there is a dimensional difference between the height H and the width W when the step portion 4a is formed by bending, the larger dimension is more likely to bend, and the corner of the step portion 4a is bent at a right angle. Because it becomes difficult. If the condition of H = W is satisfied, it becomes easy to bend the corner of the step portion 4a at a right angle, and the supporting strength of the circuit board 2 can be increased.

According to the above construction, since the insulating sheet 4 is molded to form the step portion 4a, there is an advantage that the number of parts does not increase. Moreover, since the circuit board 2 is placed on the insulating sheet 4 and the pressing piece 5 is cut and raised,
The man-hours are also small. Here, have a flexibility because the insulating sheet 4 are formed by a thin synthetic resin, its
The distance between the upper step 4a and the pressing piece 5 is set to the circumference of the circuit board 2.
By making the width wider than the thickness of the part, the circuit board 2 has an insulating sheet.
It is arranged almost freely on the toe 4, and the impact force applied to the case 1 is
Since it can be sufficiently relaxed, the impact force caused by dropping the case 1 etc.
Even if a load is applied, damage to the circuit board 2 is prevented.

If the circuit board 2 has an elongated rectangular shape as shown in FIG. 4, if the step portion 4a is formed over the entire length of the longer side of the circuit board 2, the circuit board 2 can be formed. Can be supported without being significantly bent. The pressing piece 5 may be provided as needed. Although the case 1 having a rectangular parallelepiped shape is illustrated in FIG. 2 in the above embodiment, it goes without saying that the technical idea of the present invention can be adopted even if the case 1 has another shape such as a cylindrical shape. Nor. Also,
Although the pressing piece 5 is formed on the case 1, the insulating sheet 4
You may make it formed in.

(Embodiment 2) In Embodiment 1, since the circuit board 2 is supported only by the step portion 4a formed on the insulating sheet 4, the supporting strength cannot be secured when the weight of the circuit board 2 is large. There are cases. In such a case, as shown in FIG. 5, the support piece 6 may be cut and raised in the case 1 below the step portion 4a to increase the support strength of the circuit board 3. Since other configurations are the same as those in the first embodiment, the description thereof will be omitted.

(Embodiment 3) In this embodiment, the support piece 6 is
As shown in FIG. 6, the tip end portion is bent into a substantially L shape along the inner surface of the step portion 4a. In such a structure, the stepped portion 4a is lined with a metal, and the supporting strength is further increased. Since the other configurations are the same as those in the second embodiment, the description thereof will be omitted.

(Embodiment 4) In this embodiment, instead of providing the support piece 6, both corners of the bottom of the case 1 are bent inward as shown in FIG. 7 to form the case 1 and the insulating sheet 4. By forming the step portions 1a and 4a at the same time, the step portion 4a of the insulating sheet 4 is lined. In such a configuration, if the insulating sheet 4 is laminated on the inner peripheral surface of the case 1 before the case 1 is bent,
The case 1 and the insulating sheet 4 are bent at the same time to form the step 4
Since a can be formed, there is an advantage that processing becomes easy. Here, in order to prevent the positional displacement between the case 1 and the insulating sheet 4, the case 1 and the insulating sheet 4 are preferably fixed with an adhesive or a double-sided adhesive tape.

[0018]

As described above, the present invention provides the insulation interposed between the circuit board on which electronic components are mounted and the inner peripheral surface of the case.
The sheet is placed on the periphery of the circuit board on the soldering side.
Having flexibility in a shape having a substantially L-shaped step
Since it is made of resin, it will not be damaged when dropped or impacted.
Circuit board placed on the step due to the impact absorption of the edge sheet
The impact force is not directly transmitted to the peripheral part of the
Can be stopped, and the bottom of the insulation sheet
The height of the step is the height of each electronic component mounted on the circuit board.
Since it is set to a dimension longer than the length of the
There is a concern that the lead wire of the child part will pierce the bottom of the insulating sheet.
The insulation distance between the bottom of the case and the component lead wires.
And maintain good insulation.
Directly presses the upper surface of the peripheral part of the circuit board on the component mounting side.
The holding piece for inserting is cut and raised from the case
In other words, it means that the circuit board is held only by the insulating sheet.
Since it does not have an insulating sheet,
Even the piece is cut and raised from the case, so a small presser
To prevent the circuit board from rising even with one piece
Become. As a result, a flexible insulating sheet is formed thin
Even if it does, shock absorption is obtained against drops, impacts, etc.
At the same time, the floating of the circuit board can be prevented, and
Changing the relative position between the step and the pressing piece makes it different.
A versatile set that can handle various circuit boards
The effect is that a vertical structure can be realized .

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment.

FIG. 2 is a plan view showing the first embodiment.

3 is a side view showing an insulating sheet used in Example 1. FIG.

FIG. 4 is a plan view when the circuit board is elongated according to the first embodiment.

FIG. 5 is a cross-sectional view showing a second embodiment.

FIG. 6 is a cross-sectional view showing a third embodiment.

FIG. 7 is a cross-sectional view showing a fourth embodiment.

FIG. 8 is a sectional view showing a conventional example.

FIG. 9 is a cross-sectional view showing another conventional example.

FIG. 10 is a sectional view showing still another conventional example.

[Explanation of symbols]

 1 Case 2 Circuit Board 3 Electronic Component 4 Insulation Sheet 4a Step 5 Pressing Piece

Claims (1)

(57) [Claims] 1. A circuit board is housed in a case in which an insulating sheet is interposed between a circuit board on which electronic components are mounted and an inner peripheral surface of the case, and the circuit board is separated from the inner peripheral surface of the case. In a structure of housing a circuit board to be mounted in a case, the insulating sheet has flexibility in a shape having a substantially L-shaped step portion on which a peripheral portion of the circuit board on the soldering portion side is placed.
It is made of synthetic resin and is used for the bottom of the insulation sheet.
The height of the step on the circuit board is the lead of each electronic component mounted on the circuit board.
The length is set longer than the length of the wire and
Directly presses the upper surface of the peripheral part of the circuit board on the component mounting side.
A structure for housing a circuit board in a case, characterized in that a holding piece for inserting is cut and raised from the case.