JP2007242867A - Electronic-circuit apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent both of two circuit boards from generating stresses by an external force, and to improve its manufacturing efficiency, in an electronic-circuit apparatus having a plurality of circuit boards. <P>SOLUTION: The electronic-circuit apparatus 1 has two circuit boards 5, 7 connected electrically with each other, and also has a box-form case member 3 storing these two circuit boards 5, 7 therein by laminating them successively from the side of a bottom surface 9a. Pole braces 15 extending from the bottom surface 9a integrally with the case member 3 are formed, and each step surface 15b facing the end side of each pole brace 15 is formed in the intermediate portion in the extending direction of each pole brace 15, and the circuit board 5 of one of both the circuit boards has each inserting hole 21 for passing therethrough each pole brace 15 in its thickness direction so as to insert thereinto each pole brace 15. It is constituted so as to abut on each step surface 15b, and the other circuit board 7 is fastened to the end of each pole brace 15. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic circuit device including a plurality of circuit boards on which electronic components are mounted.

In general, examples of an electronic circuit device used as a high-power electronic component module include a power transistor module and a switching power supply module.
Conventionally, in this type of electronic circuit device, it is necessary to mount a large number of electronic components, but there is a limitation in the mounting area. Therefore, there are gaps in the thickness direction between two circuit boards mounted with the large number of electronic components. It is considered that they are connected to each other via a pin (see, for example, Patent Document 1). The connection of these two circuit boards is performed by arranging a support between the two circuit boards and fastening each circuit board and the support with a screw.
The conventional electronic circuit device is configured by accommodating two connected circuit boards in a box-shaped case member. When this accommodation is performed, one circuit board is attached to the case member using a separate screw. It is fixed to.
JP-A-5-175628

However, in the above-described conventional electronic circuit device, since the other circuit board is fixed to the case member via the one circuit board, when a stress that causes the other circuit board to be bent by an external force is generated. The external force is transmitted to one circuit board via the other circuit board and the support column. And there is a possibility that stress is also generated in one of the circuit boards based on the external force.
Further, in the above-described conventional electronic circuit device, in addition to the two circuit boards and the case member, a post disposed between the two circuit boards and a screw for fixing each circuit board to the post are required. Therefore, there is a problem that the number of parts constituting the electronic circuit device increases and the number of steps for manufacturing the electronic circuit device increases.

  The present invention has been made in view of the above-described circumstances, and provides an electronic circuit device that can prevent stress from being generated on both of the two circuit boards by an external force and can also improve the manufacturing efficiency. The purpose is to do.

  As a means for solving the above-mentioned problems, the invention described in claim 1 is a box-shaped case for accommodating at least two circuit boards electrically connected to each other and stacking at least two circuit boards sequentially from the bottom side. The case member is formed with a support column that integrally extends from the bottom surface, and a stepped surface that faces the front end side is formed in a midway portion of the support column in the extending direction. One circuit board is configured to have an insertion hole that penetrates in the thickness direction thereof and allows the post to pass therethrough, and is configured to abut against the step surface, and the other circuit board is fixed to the front end side of the post. It is characterized by being.

  The invention described in claim 2 is characterized in that an operation switch capable of being pressed is mounted on the upper surface of the other circuit board facing in the same direction as the bottom surface.

When manufacturing the electronic circuit device according to these inventions, one circuit board is inserted into the support column and the back surface facing the bottom surface of the case member is brought into contact with the step surface, and then the other circuit board is mounted on the support column. What is necessary is just to fix to a front-end | tip. That is, the two circuit boards are positioned with respect to the case member by the same column formed on the case member. The interval between the two circuit boards can be easily set by appropriately adjusting the length from the tip of the support column to the step surface.
In addition, since the two circuit boards are each attached to the support column of the case member, a stress that causes the other circuit board to bend by an external force based on the pressing operation is generated by pressing the operation switch. However, the external force is not transmitted to one circuit board.

According to a third aspect of the present invention, there is provided a rod-like connecting member extending from the facing surface of the one circuit board facing the other circuit board to the other circuit board, and the two connecting members provide the two circuit boards. The circuit boards are electrically connected to each other.
According to the electronic circuit device according to the present invention, in the state where the other circuit board is fixed to the tip of the support column, one end of the connection member reaches the other circuit board. The two circuit boards can be electrically connected by simply joining them together by soldering or the like.

The invention according to claim 4 is characterized in that the case member is formed of a resin material substantially equal to a linear expansion coefficient of the connection member.
According to the electronic circuit device of the present invention, when the case member expands and contracts in response to heat, the column also expands and contracts, and the distance between the tip and the contact surface changes. However, since the case member is formed of a resin material substantially equal to the linear expansion coefficient of the connection member, the connection member expands and contracts similarly to the support column. Therefore, it is possible to prevent stress from being generated at the joint portion between the connection member and each circuit board and the connection member itself based on the expansion and contraction of the support column.

According to the first and second aspects of the present invention, since the two circuit boards are attached to the same support column formed on the case member, a stress that causes the other circuit board to be bent by an external force is generated. Even so, it is possible to prevent stress from being generated on one of the circuit boards.
In addition, it is possible to position the two circuit boards with respect to the same column formed on the case member simply by fixing the two circuit boards to the case member, and an electronic device including two circuit boards arranged with a gap therebetween. A circuit device can be manufactured. Therefore, the manufacturing efficiency of the electronic circuit device can be improved. That is, as in the prior art, there is no need for a separate support disposed between two circuit boards or screws for fastening each circuit board to the support, and the number of components of the electronic circuit device can be reduced. The number of manufacturing steps of the device can be reduced.

  According to the invention of claim 3, two circuits can be obtained simply by joining one end of a rod-like connecting member standing on the opposing surface of one circuit board and the other circuit board fixed to the tip of the column. Since the substrates can be electrically connected, the electronic circuit device can be more easily manufactured.

  According to the fourth aspect of the present invention, since no stress is generated in the connection portion between the connection member and each circuit board or the connection member itself based on the expansion and contraction of the support column in response to heat, the connection portion itself is broken. It is possible to prevent the connection member from being disconnected. Therefore, the electrical connection between the two circuit boards can be reliably maintained.

  FIG. 1 shows an embodiment according to the present invention. As shown in FIG. 1, the electronic circuit device 1 according to this embodiment includes a box-shaped case member 3 that opens upward, and two circuit boards 5 and 7 that are accommodated in the case member 3. Yes. The case member 3 includes a bottom wall portion 9 formed in a substantially plate shape, and a side wall portion 11 that stands integrally from the bottom surface 9a of the bottom wall portion 9 and surrounds the bottom surface 9a. The bottom wall portion 9 is formed with a plurality of two types of support columns 13 and 15 extending integrally from the bottom surface 9a at intervals.

  The plurality of first support columns 13 are respectively disposed on the periphery of the bottom surface 9 a, and the height dimensions from the bottom surface 9 a to the tip surface 13 a of each first support column 13 are substantially equal to each other. A female screw portion 17 for fixing the first circuit board (one circuit board) 5 is provided at the tip of each first support column 13. The female screw portion 17 is configured by a metallic cylindrical member (not shown) fixed to a hole recessed from the distal end surface 13 a of the first support column 13. That is, the internal thread part 17 is formed in the internal peripheral surface of the said cylindrical member.

The plurality of second support columns 15 are arranged inside the first support column 13, and the height dimensions from the bottom surface 9 a to the tip end surface 15 a of each second support column 15 are substantially equal to each other.
Further, these second support columns 15 are formed higher than the first support columns 13. A female screw portion 19 for fixing the second circuit board (the other circuit board) 7 is provided at the tip of each second support column 15. The female thread portion 19 is configured by a metal cylindrical member (not shown) fixed in a hole recessed from the distal end surface 15a of the second strut 15 in the same manner as the female thread portion 17 of the first strut 13. Yes.

A stepped surface 15 b facing the tip side of the second support column 15 is formed in the middle of the extending direction of each second support column 15. That is, the base end portion of the second support column 15 positioned on the bottom surface 9a side of the bottom wall portion 9 with respect to the step surface 15b is the front end portion of the second support column 15 positioned on the front end surface 15a side of the step surface 15b. It is formed larger than. Note that the height dimension from the bottom surface 9 a of the bottom wall portion 9 to the step surface 15 b is substantially equal to the height dimension of the tip surface 13 a of the first support column 13.
The case member 3 configured as described above is formed of a resin material having a linear expansion coefficient of 20 to 80 ppm / ° C. such as PBT (polybutylene terephthalate).
The two circuit boards 5 and 7 are sequentially accommodated from the bottom surface 9a side of the case member 3 and are arranged in the case member 3 with a gap therebetween. The circuit boards 5 and 7 are configured by mounting various electronic components (not shown) or the like on both surfaces.

The first circuit board 5 disposed on the bottom surface 9 a side of the case member 3 is disposed in contact with the tip surface 13 a of the first column 13 and the step surface 15 b of the second column 15. That is, the first circuit board 5 is formed with a plurality of insertion holes 21 that penetrate the second support column 15 in the thickness direction. Each insertion hole 21 has a size that allows the distal end portion of the second support column 15 to be inserted, and is formed to be smaller than the proximal end portion of the second support column 15 so as to contact the stepped surface 15b. Yes.
Further, a fixing hole 23 corresponding to the female screw portion 17 is formed through the peripheral edge of the first circuit board 5 in contact with the front end surface 13 a of the first support column 13. The first circuit board 5 is fixed to the case member 3 by inserting the fixing screw 25 into the fixing hole 23 and screwing the fixing screw 25 into the female screw portion 17 of the first support column 13. In this state, the first circuit board 5 is disposed between the bottom surface 9 a of the case member 3 with a gap.

The second circuit board 7 disposed on the opening side of the case member 3 is formed to be smaller than the first circuit board 5, and its peripheral edge is in contact with and fixed to the tip surface 15 a of the second support column 15. ing. That is, a fixing hole 27 that penetrates in the thickness direction is formed at a position corresponding to the female screw portion 19. Then, the second circuit board 7 is fixed to the case member 3 by inserting the fixing screw 29 into the fixing hole 27 and screwing the fixing screw 29 into the female screw portion 19 of the second support column 15. In this state, the second circuit board 7 is disposed between the first circuit board 5 and a gap.
An operation switch 31 having an operation button 31a that can be pressed is mounted on the upper surface 7a of the second circuit board 7 facing in the same direction as the bottom surface 9a of the case member 3. The mounting position of the operation switch 31 is preferably in the vicinity of the second support column 15. The fixing screw 29 for fixing the second circuit board 7 is formed with a female screw portion 33 on the opening side of the case member 3.

These two circuit boards 5 and 7 are electrically connected to each other via a connecting member 35 formed in a substantially rod shape. The connection member 35 is erected on the facing surface 5 a of the first circuit board 5 facing the second circuit board 7, and one end thereof extends to the second circuit board 7. Both ends of the connection member 35 are joined to the circuit boards 5 and 7 by soldering or the like.
Further, a bent portion 35 a is formed in the middle portion of the connection member 35. The bent portion 35a is elastically deformed when a change occurs in the gap between the two circuit boards 5 and 7 with both ends of the connection member 35 being joined to the circuit boards 5 and 7, respectively. It plays the role which suppresses that stress generate | occur | produces in the junction part of the board | substrates 5 and 7 and the connection member 35. FIG.
The connection member 35 is made of brass having good conductivity. That is, the linear expansion coefficient of the case member 3 described above is substantially equal to that of the connection member 35 made of brass.

  The electronic circuit device 1 further includes a resin mold portion 37 that is filled in the case member 3 and integrally fixes the case member 3 and the two circuit boards 5 and 7. The resin mold part 37 is made of urethane resin, and embeds two circuit boards 5 and 7 and various electronic components mounted on them. That is, the resin mold portion 37 is formed as a moisture-proof measure for the electric circuit of the electronic circuit device 1 including the circuit boards 5 and 7 and various electronic components, and protects the circuit boards 5 and 7 and various electronic components. Playing a role. The female screw portion 33 of the fixing screw 29 for fixing the second circuit board 7 and the operation button 31 a of the operation switch 31 mounted on the second circuit board 7 are disposed outside the resin mold portion 37. .

Hereinafter, a method for manufacturing the electronic circuit device 1 configured as described above will be described.
First, the case member 3 made of a resin material is molded using a predetermined mold (not shown). At this time, in a state where the cylindrical members constituting the female thread portions 17 and 19 of the first support column 13 and the second support column 15 are provided at predetermined positions in the mold, the molten resin is put into the mold. Pour. Thereby, each cylindrical member is fixed to the hole recessed from the front end surfaces 13a and 15a of the first support column 13 and the second support column 15.
Further, the other end of the connecting member 35 is joined to the facing surface 5a of the first circuit board 5 by soldering or the like, and the connecting member 35 is erected on the facing surface 5a.

Next, the second support column 15 is inserted into the insertion hole 21 of the first circuit board 5, and the first circuit board 5 is inserted into the tip surface 13 a of the first support column 13 and the step surface 15 b of the second support column 15. Make contact. As a result, the first circuit board 5 is positioned with respect to the case member 3. Thereafter, the first circuit board 5 is fixed to the case member 3 by screwing the fixing screw 23 into the female screw portion 17 of the first support column 13.
After the positioning of the first circuit board 5 is completed, the second circuit board 7 is disposed on the distal end surface 15a of the second support column 15, and the fixing screw 29 is attached to the female screw portion 19 of the second support column 15. Screw together. Thereby, the second circuit board 7 is fixed to the case member 3, that is, the second circuit board 7 is positioned with respect to the case member 3.

As described above, the two circuit boards 5 and 7 are fixed to the case member 3 in a state of being spaced apart from each other. In addition, the said space | interval can be easily set by adjusting suitably the length from the front end surface 15a of the 2nd support | pillar 15 to the level | step difference surface 15b.
Further, in a state where the second circuit board 7 is fixed to the distal end surface 15 a, one end of the connection member 35 reaches the second circuit board 7, and one end of the connection member 35 is connected to the second circuit board 7. To be joined by soldering or the like. As a result, the two circuit boards 5 and 7 are electrically connected to each other.
After these two circuit boards 5 and 7 are attached to the case member 3, the case member 3 is filled with urethane resin, and the two circuit boards 5 and 7 and various electronic components mounted thereon are embedded. Thus, the manufacture of the electronic circuit device 1 is completed.

When the electronic circuit device 1 manufactured as described above is used, when the operation button of the operation switch is pressed, a stress that causes the second circuit board 7 to bend by an external force based on the pressing operation is the second. It occurs on the circuit board 7. Here, since the two circuit boards 5 and 7 are each independently fixed to the case member 3 and the resin mold portion 37 made of urethane resin is elastically deformed to absorb the stress, the stress is There is no transmission to the first circuit board 5.
Further, when the second circuit board 7 bends, the interval between the two circuit boards 5 and 7 changes, but the bent portion 35a of the connecting member 35 elastically deforms so as to follow the change in the interval. It is possible to prevent stress from being generated at the joint portion between the connection member 35 and the circuit boards 5 and 7.

  Further, in the electronic circuit device 1, when the case member 3 expands and contracts in response to heat, the second support column 15 also expands and contracts, so that the distance between the tip surface 15a and the step surface 15b changes. The interval between the two circuit boards 5 and 7 changes. Here, since the case member 3 is formed of a resin material substantially equal to the linear expansion coefficient of the connection member 35, the connection member 35 expands and contracts similarly to the second support column 15. Therefore, it is possible to prevent stress from being generated in the joint portion between the connection member 35 and the circuit boards 5 and 7 and the connection member 35 itself based on the expansion and contraction of the second support column 15.

As described above, according to the electronic circuit device 1, the two circuit boards 5 and 7 are independently attached to the second support column formed on the case member 3, so that the second circuit is generated by an external force. Even if a stress that causes the substrate 7 to bend is generated, it is possible to prevent the stress from being generated on the first circuit board 5.
In addition, the two circuit boards 5 and 7 can be positioned with respect to the second support column 15 formed on the case member 3 by simply fixing the two circuit boards 5 and 7 to the case member 3 respectively, with a gap therebetween. The electronic circuit device 1 including the two circuit boards 5 and 7 arranged can be manufactured. Therefore, the manufacturing efficiency of the electronic circuit device 1 can be improved. That is, as in the prior art, there is no need for a separate support disposed between two circuit boards or screws for fastening each circuit board to the support, and the number of components of the electronic circuit device 1 can be reduced. The number of manufacturing steps of the circuit device 1 can be reduced.

Furthermore, two circuits can be obtained simply by joining one end of the connecting member 35 erected on the facing surface 5 a of the first circuit board 5 and the second circuit board 7 fixed to the tip of the second support column 15. Since the substrates 5 and 7 can be electrically connected, the electronic circuit device 1 can be more easily manufactured.
In addition, since no stress is generated in the connection portion between the connection member 35 and the circuit boards 5 and 7 and the connection member 35 itself based on the expansion and contraction of the second support column 15 corresponding to heat, the connection member 35 itself is broken. Or disconnection of the connection member 35 can be prevented. Therefore, the electrical connection between the two circuit boards 5 and 7 can be reliably maintained.

Furthermore, by forming the second circuit board 7 smaller than the first circuit board 5, the circuit board based on the pressing operation is compared with the case where the operation switch 31 is provided on the first circuit board 5. Can be reduced. Furthermore, the amount of bending of the second circuit board 7 can be further reduced by arranging the operation switch 31 in the vicinity of the second support column 15.
Further, in addition to the peripheral edge of the first circuit board 5 being supported by the tip surface 13 a of the first support column 13, the gap between the peripheral edges of the first circuit board 5 is also provided by the step surface 15 b of the second support column 15. Since it is supported, it is possible to prevent the first circuit board 5 fixed to the case member 3 from being bent by its own weight or various electronic components to be mounted.

  Further, by forming a female screw portion 33 exposed outward from the resin mold portion 37 on a fixing screw for fixing the second circuit board 7 to the case member 3, the electronic circuit device 1 is mounted on a separate frame F. When attaching, it becomes possible to screw to the frame F using the female screw portion 33. That is, since the female screw portion 33 can be used as a connecting mechanism for attaching the electronic circuit device 1 to the frame F, it is not necessary to separately provide the connecting mechanism in the electronic circuit device 1, and the components of the electronic circuit device 1 are eliminated. The score can be further reduced.

In the above-described embodiment, the cylindrical members constituting the female thread portions 17 and 19 of the first support column 13 and the second support column 15 form the case member 3 and simultaneously the first support column 13 and the second support member 13. Although it was fixed to the support | pillar 15, it is not restricted to this, For example, after shape | molding the case member 3, it is in the hole formed in the front end surfaces 13a and 15a of the 1st support | pillar 13 and the 2nd support | pillar 15. You may press-fit each.
Moreover, although the internal thread parts 17 and 19 of the 1st support | pillar 13 and the 2nd support | pillar 15 were comprised with the metal cylindrical members, it is not restricted to this, The 1st support | pillar 13 and the 2nd support | pillar It may be formed directly on the column 15.

Furthermore, the case member 3 is formed of a resin material having a linear expansion coefficient of 20 to 80 ppm / ° C. such as PBT. However, the case member 3 is not limited to this, and at least approximately the linear expansion coefficient of the connection member 35. What is necessary is just to be formed with the same resin material.
Moreover, although the bent part 35a was formed in the middle part of the connection member 35, it is not restricted to this, It does not need to be formed especially. Even in this configuration, the case member 3 is formed of a resin material having a linear expansion coefficient substantially equal to that of the connection member 35, so that even if the case member 3 is thermally deformed, the circuit boards 5 and 7 and the connection member 35 It can suppress that a stress generate | occur | produces in this junction part.

Further, although the first circuit board 5 is fixed to the case member 3 by the fixing screw 25 and the female screw part 17 of the first support column 13, the first circuit board 5 is embedded in the resin mold part 37. The fixing screw 25 and the female thread portion 17 of the first support column 13 do not need to be provided in particular because it is possible to fix the case member 3 to the case member 3.
Moreover, although the resin mold part 37 was formed with urethane resin, it is not restricted to this, It should just be formed with the resin material which can be elastically deformed at least. In addition, when the protection of the circuit boards 5 and 7 and various electronic components is not taken into consideration, the resin mold portion 37 may not be particularly formed.

Furthermore, although the electronic circuit device 1 includes the two circuit boards 5 and 7, the electronic circuit device 1 is not limited thereto, and may include three or more circuit boards. In the case of this configuration, similarly to the step surface 15b of the above embodiment, a plurality of step surfaces are formed on the second support column 15, and one circuit board fixed to the tip of the second support column 15 is provided. Except for this, the circuit board may be brought into contact with each step surface.
As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

1 is a side sectional view of an electronic circuit device according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic circuit apparatus 3 Case member 5 1st circuit board (one circuit board)
5a Opposing surface 7 Second circuit board (the other circuit board)
7a Upper surface 9a Bottom surface 15 Second support column 15b Stepped surface 21 Insertion hole 31 Operation switch 35 Connection member

Claims (4)

An electronic circuit device comprising at least two circuit boards that are electrically connected to each other and a box-shaped case member that houses the at least two circuit boards stacked in order from the bottom side,
The case member is formed with struts extending integrally from the bottom surface,
A stepped surface facing the tip side is formed in the middle of the extending direction of the column,
One of the circuit boards is configured to have an insertion hole that penetrates in the thickness direction and allows the post to pass through, and is in contact with the stepped surface.
An electronic circuit device, wherein the other circuit board is fixed to a front end side of the support column.   The electronic circuit device according to claim 1, wherein an operation switch that can be pressed is mounted on an upper surface of the other circuit board facing in the same direction as the bottom surface. A rod-shaped connecting member extending from the facing surface of the one circuit board facing the other circuit board to the other circuit board is provided;
The electronic circuit device according to claim 1, wherein the two circuit boards are electrically connected to each other by the connection member. The electronic circuit device according to claim 3, wherein the case member is formed of a resin material that is substantially equal to a linear expansion coefficient of the connection member.

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