JP4593629B2 - Fastening structure of circuit board - Google Patents

Description

  The present invention relates to a fastening part structure of a circuit board that is fastened to a chassis of an electronic device.

  In general, a part of a circuit board of an electronic device is fastened to a chassis with a screw. At the time of fastening, a component mounting surface or circuit pattern forming surface of the circuit board and the chassis are held apart at a predetermined interval. In most cases, the circuit board and the chassis are fastened with screws. As such a conventional circuit board fastening portion structure, a concave portion is drawn at the board fastening portion of the chassis, and the front end surface (bottom portion) of the concave portion is brought into contact with the circuit board. A configuration in which the bottom of the concave portion and the circuit board are fastened with screws is already known. Here, the concave portion of the chassis is formed so that the bottom area is larger than the diameter of the head of the screw housed in the concave portion, and when the chassis and the circuit board are fastened, the concave portion of the chassis is formed. The entire bottom surface is joined to the circuit board.

  The above prior art is a technique generally known to those skilled in the art, and does not relate to a known literature invention.

  In addition, as a fastening part structure of a circuit board according to another conventional example, a board seating surface having a convex cross section is drawn at a board fastening part of a chassis (housing), and a burring process is performed on the board seating surface to screw A spring washer and a flat washer are interposed between the circuit board and the screw head formed in contact with and supported on the board seat surface, and the chassis and circuit board are connected to the screw hole via the washers. There is already known a configuration in which a screw is fastened and fixed with a screw (see, for example, Patent Document 1).

JP 2001-332878 (paragraph [0057], FIG. 2)

  Since the conventional circuit board fastening structure is configured as described above, the contact area between the bottom surface of the concave portion formed in the board fastening portion of the chassis and accommodating the screw head and the circuit board is large. Therefore, there is a problem that the effective area of the circuit board is reduced accordingly. That is, since the bottom surface of the concave portion formed on the chassis with a bottom area larger than the diameter of the screw head and the circuit board are in contact with each other without a gap, a circuit pattern is formed in the contact area between the bottom surface of the concave portion on the circuit board. There is a problem in that the effective area of the circuit board is reduced because it is not possible to form the mounting parts or to arrange the mounting parts, thereby hindering the downsizing of the electronic device.

Also in Patent Document 1, since the circuit board is in contact with the board seating surface drawn to the chassis without any gap, and the flat washer is in contact with the circuit board without any gap, the above-described conventional circuit board is also provided. As in the case of the fastening structure, the circuit board has an effective area without being able to form a circuit pattern or dispose a mounting component in the contact area of the circuit board with the board seating surface of the chassis and the flat washer. In addition, the flat washer and the spring washer have to be interposed between the screw head and the circuit board. For this reason, there is a problem that the number of parts increases and the cost increases.

  The present invention has been made to solve the above-described problems. The circuit board is formed between the bottom of the concave portion and the circuit board, while the chassis is provided with a concave portion for fastening the circuit board. An object of the present invention is to obtain a fastening part structure of a circuit board that can increase the effective area of the circuit board.

In the circuit board fastening portion structure according to the present invention, a concave portion for fastening a circuit board is formed in the chassis, and the circuit board and the chassis are fastened by a fastening member via the bottom of the concave portion. In the part structure, the fastening member is inserted so as to protrude toward the circuit board side, and the tip is in contact with the ground member having a plurality of ground terminals on the circuit board so as to electrically connect the circuit board and the chassis. the bottom integrally formed a cylindrical portion, a gap portion provided between the bottom and the circuit board of the concave portion is brought into contact with the distal end to the circuit board, to so that the earth terminal is arranged in the region of the air gap It is composed.

In the circuit board fastening portion structure according to the present invention, a concave portion for fastening a circuit board is formed in the chassis, and the circuit board and the chassis are fastened by a fastening member via the bottom of the concave portion. In the part structure, a fastening member is inserted into a grounding member having a plurality of grounding terminals mounted on the circuit board so as to protrude toward the chassis side, and the tip abuts against the bottom of the concave portion to A cylindrical part is integrally formed on the grounding member so that it can be connected, and the tip is brought into contact with the chassis to provide a gap between the bottom of the concave part and the circuit board. are those configured to so that.

According to the present invention, in the fastening part structure of the circuit board formed by forming the concave part for fastening the circuit board in the chassis and fastening the circuit board and the chassis with the fastening member through the bottom part of the concave part, A cylindrical member is formed at the bottom of the concave portion so that the fastening member is inserted to protrude to the side, and the tip contacts the ground member having a plurality of ground terminals on the circuit board to electrically connect the circuit board and the chassis. the integrally formed, a gap portion provided between the bottom and the circuit board of the concave portion is brought into contact with the distal end to the circuit board, the ground terminal in the area of the gap portion is configured to so that is arranged, said circuit It is possible to form a circuit pattern to be disposed in the gap portion or mount an electronic component or the like at a position corresponding to the bottom surface of the concave portion on the substrate, which increases the effective area of the circuit substrate. Effective . In addition, as described above, the circuit board and the chassis can be electrically connected by bringing the tip of the cylindrical part integrally formed on the bottom of the concave part of the chassis into contact with the circuit board. For this reason, there is an effect that the grounding structure of the circuit board can be realized by the cylindrical part integrated with the concave part without requiring a grounding member separate from the chassis and the circuit board. Furthermore, since a member separate from the chassis and the circuit board is not required to form the gap, there is an effect that the number of parts can be reduced and the cost can be reduced.

According to the present invention, in the fastening part structure of the circuit board formed by forming the concave part for fastening the circuit board in the chassis and fastening the circuit board and the chassis with the fastening member through the bottom part of the concave part, The ground member having a plurality of ground terminals mounted thereon projects into the chassis side to be inserted into the fastening member , and the tip is in contact with the bottom of the concave portion so as to electrically connect the circuit board and the chassis. integrally formed a cylindrical portion member, a gap portion provided between the bottom and the circuit board of the concave portion is brought into contact with the tip to the chassis, the ground terminal in the region of the gap portion is configured to so that is placed Therefore, the ground member can be disposed in the gap formed between the bottom of the concave portion and the circuit board by the cylindrical portion integral with the ground member, and thus the effective area of the circuit board is reduced. Increase There is an effect that. Further, as described above, the gap portion can be formed by the cylindrical portion integral with the ground member, and a member separate from the ground member is not required to form the gap portion. There is an effect that the number of points can be reduced and the cost can be reduced.

Hereinafter, in order to explain the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Reference example .
FIG. 1 is a cross-sectional view showing a fastening structure of a circuit board according to a reference example of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA in FIG.
The fastening part structure of the circuit board shown in FIG. 1 is a fastening screw (fastening member) that connects, for example, a chassis 2 formed of a lid member of a housing 1 in an in-vehicle electronic device and a circuit board 3 housed in the housing 1. ) It is the general composition concluded in 4. More specifically, a substrate support post 5 having a screw hole 5a is erected on the bottom of the housing 1. On the other hand, the circuit board 3 is provided with a screw insertion hole 3 a for communicating with the screw hole portion 5 a of the post 5.

  That is, the circuit board 3 is placed on the post 5 in a position where the screw insertion hole 3 a communicates with the screw hole portion 5 a of the post 5. Then, the circuit board 3 placed on the post 5 and the chassis 2 disposed on the circuit board 3 are fastened and fixed with a fastening screw 4 screwed into the screw hole 5a of the post 5. It is supposed to be.

  Next, the details of the chassis 2 will be described. The board fastening portion in the chassis 2 includes a tapered concave portion 2a and a fastening screw that protrudes from the center of the bottom of the concave portion 2a toward the circuit board 3 side. The cylindrical portion 2b for insertion is integrally formed by burring. Here, the concave portion 2a is formed in such a size that the bottom portion thereof forms a seating surface of the head portion 4a of the tightening screw 4, and the cylindrical portion 2b has an inner diameter into which the screw shaft portion of the tightening screw 4 can be inserted. In addition, the outer diameter of the circuit board 3 is larger than that of the screw insertion hole 3a. Therefore, when the chassis 2 and the circuit board 3 are fastened by the fastening screw 4, the tip of the cylindrical part 2 b abuts on the circuit board 3, and a gap is formed between the bottom of the concave part 2 a and the circuit board 3. S is formed.

Next, the operation will be described. Here, assembly fastening of the circuit board 3 and the chassis 2 will be described.
After positioning the circuit board 3 on the post 5 in the housing 1 and positioning the chassis 2 on the circuit board 3, the screw hole 5a of the post 5 and the screw insertion hole of the circuit board 3 are positioned. 3a and the cylindrical part 2b of the chassis 2 are connected. In this state, the fastening screw 4 is screwed and tightened from the inside of the recessed portion 2a of the chassis 2 to the screw hole portion 5a of the post 5 through the cylindrical portion 2b and the screw insertion hole 3a of the circuit board 3, thereby The circuit board 3 and the chassis 2 are fastened and fixed on the post 5. In the fastened state, the tip of the cylindrical portion 2b protruding from the bottom of the concave portion 2a of the chassis 2 abuts on the circuit board 3 so that the bottom of the concave portion 2a of the chassis 2 and the circuit board 3 A gap S is formed between the two.

According to the reference example described above, the concave portion 2a capable of accommodating the head 4a of the fastening screw 4 at the circuit board fastening portion of the chassis 2, and the bottom of the concave portion 2a protrudes toward the circuit board 3 on the post 5. The cylindrical portion 2b into which the fastening screw 4 is inserted is integrally formed, and the tip of the cylindrical portion 2b is brought into contact with the circuit board 3 so that the bottom of the concave portion 2a and the circuit board 3 Since the gap S is formed between them, the effective area of the circuit board 3 is reduced by the gap S compared to the conventional example in which the entire bottom of the concave portion 2a is in contact with the circuit board 3. Has the effect of increasing. That is, a circuit pattern arranged in the space S formed by the cylindrical portion 2b between the bottom of the concave portion 2a of the chassis 2 and the circuit board 3 is formed on the circuit board 3, or the circuit Mounting components such as electronic components having a height mounted on the substrate 3 can be arranged in the gap S, and the degree of freedom in circuit pattern design can be improved, contributing to downsizing of electronic devices. There is an effect. Furthermore, it is also possible to arrange a grounding member in the gap S, and in this case, there is an effect that the grounding member and the chassis 2 can be electrically connected by the cylindrical part 2b.

Embodiment 1 FIG .
3 is a cross-sectional view showing the structure of the fastening portion of the circuit board according to the first embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along the line BB in FIG. Are denoted by the same reference numerals, and redundant description is omitted.
In the first embodiment , the tip of the cylindrical portion 2b of the chassis 2 according to the reference example is brought into contact with the root portion of the ground member (ground plate) 6 mounted on the circuit board 3 so as to connect the chassis 2 and the circuit. By fastening the board 3 with the fastening screw 4, the chassis 2 and the ground member 6 are electrically connected via the cylindrical part 2b. The ground member 6 is formed by integrally forming a plurality of ground terminal portions 6a having a height.

According to the first embodiment configured as described above, the cylindrical portion 2b of the chassis 2 is formed between the bottom of the concave portion 2a of the chassis 2 and the circuit board 3 as in the case of the reference example . Since the ground member 6 in which a plurality of ground terminal portions 6a having a height are formed can be disposed in the region of the space S, the ground member 6 having such a height can be disposed in the region of the space S. There is an effect that it can be mounted on the circuit board 3.

Embodiment 2 FIG .
FIG. 5 is a sectional view showing a fastening structure of a circuit board according to Embodiment 2 of the present invention, and FIG. 6 is a sectional view taken along line CC in FIG. Are denoted by the same reference numerals, and redundant description is omitted.
In the reference example and the first embodiment , the cylindrical portion 2b is integrally formed at the center of the bottom of the concave portion 2a of the chassis 2. However, in the second embodiment , the root portion of the ground member 6 mounted on the circuit board 3 is used. The cylindrical portion 6b is integrally formed, and the end of the cylindrical portion 6b is brought into contact with the bottom of the concave portion 2a so that the chassis 2 and the circuit board 3 are fastened by the fastening screw 4. is there. As in the case of the first embodiment , the ground member 6 is formed by integrally forming a plurality of ground terminal portions 6a having a height.

According to the second embodiment configured as described above, the gap portion S can be formed between the bottom of the concave portion 2a of the chassis 2 and the circuit board 3 by the cylindrical portion 6b integrated with the ground member 6, There is an effect that the ground member 6 formed with a plurality of ground terminal portions 6 a having a height can be mounted on the circuit board 3 so as to be disposed between the bottom of the concave portion 2 a and the circuit board 3. is there. Further, since no separate member such as a washer is required to form the gap S, there is an effect that the number of parts can be reduced and the cost can be reduced.

  As described above, the circuit board fastening portion structure according to the present invention is excellent in increasing the effective area of the circuit board and is suitable for obtaining a miniaturized electronic device.

It is sectional drawing which shows the fastening part structure of the circuit board by the reference example of this invention. It is a cross-sectional arrow view along the AA line of FIG. It is sectional drawing which shows the fastening part structure of the circuit board by Embodiment 1 of this invention. It is a cross-sectional arrow view along the BB line of FIG. It is sectional drawing which shows the fastening part structure of the circuit board by Embodiment 2 of this invention. FIG. 6 is a cross-sectional arrow view along the line CC in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case, 2 Chassis, 2a Concave part, 2b Cylindrical part, 3 Circuit board, 3a Screw insertion hole, 4 Fastening screw (fastening member), 4a Head, 5 post, 5a Screw hole part, 6 Ground member, 6a Ground terminal part, 6b Cylindrical part.

Claims (2)

In the fastening part structure of the circuit board formed by forming a concave part for fastening the circuit board in the chassis, and fastening the circuit board and the chassis with a fastening member through the bottom part of the concave part,
The fastening member is inserted so as to protrude toward the circuit board, and the tip is in contact with a ground member having a plurality of ground terminals on the circuit board to electrically connect the circuit board and the chassis. A cylindrical portion is integrally formed at the bottom of the concave portion, the tip is brought into contact with the circuit board, and a gap is provided between the bottom of the concave portion and the circuit board. fastening part structure of a circuit board, wherein a terminal is configured to so that disposed. In the fastening part structure of the circuit board formed by forming a concave part for fastening the circuit board in the chassis, and fastening the circuit board and the chassis with a fastening member through the bottom part of the concave part,
The fastening member is inserted into a ground member having a plurality of ground terminals mounted on the circuit board so as to protrude toward the chassis side, and the tip is in contact with the bottom of the concave portion, and the circuit board and the chassis A cylindrical portion is formed integrally with the ground member so as to be electrically connected to each other, and a gap portion is provided between the bottom portion of the concave portion and the circuit board by bringing the tip into contact with the chassis. fastening part structure of a circuit board, characterized in that within the region and the ground terminal and configured to so that disposed.

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