JP2001196767A - Printed wiring board holding structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate generation of chatter noise. SOLUTION: In a conventional printed board holding structure, there are arranged a printed wiring board, a body where a mounting part on which the printed wiring board to be mounted is protruded from the inner wall, and a lid body part where a pressing part pressing the printed wiring board against the mounting part is protruded from an inner wall. The printed wiring board is clamped with the mounting part of the body and the pressing part of the lid body. Chatter noise is generated by the movement of the printed wiring board in the horizontal direction. In this structure, unevenness is formed on a mounting surface of the mounting part of the above printed board holding structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a housing structure for holding a printed wiring board used for electronic equipment and the like.

[0002]

2. Description of the Related Art Conventionally, when a printed wiring board is housed in a housing such as a resin case, a rectangular cylindrical main body 92 with a bottom is required.
It is widely used because it is inexpensive and can be easily mounted by being sandwiched and held by the cover 93. FIG. 5 is an exploded perspective view showing a conventional printed wiring board holding structure, and FIG. 6 is a sectional view showing a conventional printed wiring board holding structure.

A general holding structure of the printed wiring board 91 is such that the printed wiring board 91 on which electronic components are mounted is attached to the main body 9.
It is structured so as to be held between the cover 2 and the lid 93. A plurality of mounting portions 921 that support the printed wiring board 91 from below are protruded from the inner wall of the main body 92. Further, a plurality of fitting holes 923 for fitting with the lid 93 are provided near the upper opening edge. A plurality of pressing portions 931 for pressing the printed wiring board 91 from above are protrudingly provided on the wall end surface of the lid 93. Also, a fitting hole 923 of the main body 92 is provided.
The same number of fitting claws 933 are provided at positions corresponding to the fitting holes 923. Further, the shape and dimensions of the printed wiring board 91 are slightly smaller than the inner wall dimensions of the main body, so that the printed wiring board 91 can be easily mounted on the main body 92.

Then, the printed wiring board 91 is sandwiched between the lid 93, the pressing portion 931 of the main body 92, and the mounting portion 921 from the vertical (vertical) direction to slightly bend the printed wiring board 91. The printed wiring board 91 is fixed by the reaction force of 91 (FIG. 6). Further, by fitting the fitting hole 923 and the fitting claw 933 (FIG. 6), the main body portion 92 and the lid portion 93 are connected, and the printed wiring board 9 is formed.
1 is housed in a housing (FIG. 6).

[0005]

However, in the holding structure using the reaction force of the printed wiring board 91, the holding of the printed wiring board 91 in the horizontal direction is insufficient. A chattering noise occurs when moving in the direction. Therefore, if a structure is adopted in which the reaction force is increased in order to strengthen the fixing, the warp of the printed wiring board 91 will increase, and stress will be generated at the soldered portion of the mounted component, which may cause solder cracks. Further, the horizontal positioning by bringing the end surface of the printed wiring board 91 into close contact with the inner wall of the main body 92 has a problem that the insertability of the printed wiring board 91 into the main body 92 is deteriorated.
Further, the structure in which the printed wiring board 91 is fixed to the main body portion 92 with screws can prevent rattling and bending, but also has a problem that the material cost and the number of processing steps are increased, and the mounting area of the electronic component is reduced. The present invention aims to solve the above-mentioned problems.

[0006]

According to the present invention, there is provided a printed wiring board, a main body having a mounting portion on which the printed wiring board is mounted protruding from an inner wall, and A pressing portion for pressing the printed wiring board against the mounting portion comprises a lid protruding from the inner wall, and the printed wiring board is sandwiched between the mounting portion of the main body and the pressing portion of the lid portion. In the printed circuit board holding structure described above, the mounting surface of the mounting portion has irregularities.

Further, the printed wiring board is characterized in that a portion of the printed wiring board which comes into contact with the placement surface is formed of an elastic member having elasticity.

[0008] Further, the printed wiring board is characterized in that irregularities are formed in a portion in contact with the mounting surface.

Further, the unevenness formed on the mounting surface and the unevenness formed on the printed wiring board are a plurality of grooves extending in the same direction.

[0010] Further, the unevenness formed on the printed wiring board is formed by solder for connecting components on the printed wiring board.

Further, the unevenness formed on the printed wiring board is formed of a resin coating for printing for display or the like on the printed wiring board.

Further, the groove formed on at least one of the mounting portions is different from the groove formed on another mounting portion in a direction in which the groove extends.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A holding structure for a printed wiring board according to a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a structural view showing a printed wiring board holding structure according to a first embodiment of the present invention. FIG. 1 (a) is a cross-sectional view showing the printed wiring board holding structure, and FIG. ,
(C) is a plan view of the mounting surface.

A resin housing for protecting the printed wiring board 1 on which electronic parts and the like are mounted is formed into a rectangular box shape by injection molding, and is divided into a main body portion 12 and a lid body portion 13 to be printed. Is held so as to be sandwiched.

The main body 12 has a mounting portion 121 on which the printed wiring board 1 is mounted and an engagement hole 123.
The mounting portion 121 supports the printed wiring board 1 from below, and a plurality of the mounting portions 121 protrude along the inner wall of the main body portion 12.
The mounting surface 122 of the mounting portion 121 that is in contact with the printed wiring board 1 is provided with irregularities. The engagement holes 123 are used to engage the main body 12 and the lid 13, and are a plurality of rectangular holes provided near the opening end face of the main body 12.

The cover 13 has a pressing portion 131 and an engaging claw 1.
33 are provided. The pressing portion 131 is mounted on the placing portion 121.
The printed wiring board 1 supported from below is pressed and held from above, and a plurality of the printed wiring boards 1 are protruded from the wall end surface of the lid 13. The number of the engaging claws 133 is such that the width of the protrusion from the side wall surface increases toward the bottom from the opening side of the lid 13 and is provided in a number corresponding to the position corresponding to the engaging hole 123. The printed wiring board 1 is large enough to have a slight clearance from the inner wall of the main body 12 in its outer dimensions. A resilient member 51 having elasticity such as an elastic adhesive is applied to a surface that comes into contact with the mounting surface 122, or a sheet-like elastic member 51 such as a rubber plate is adhered.

Next, the operation of assembling the printed wiring board holding structure will be described. First, the printed wiring board 1 on which electronic components and the like are mounted on the main body 12 is inserted and placed from the upper opening side. Then, the main body 12 is fitted into the main body 12 with the opening side of the lid 13 facing downward, and the plurality of engaging claws 133 are
Push until it engages. Then, the pressing portion 1 of the lid 13
31 pushes down the upper surface of the printed wiring board 1 which is stationary in contact with the mounting portion 13 of the main body 12. Thereby, the printed wiring board 1 is pressed by the pressing portion 131 from the upper surface, and is fixed at a predetermined position.

As described above, in the first embodiment, the unevenness of the mounting surface 122 at a plurality of locations and the elastic member at the contact portion of the printed wiring board 1 are cut off (FIG. 1B). Since the frictional force increases, rattling of the printed wiring board 1 in the horizontal direction (front, rear, left and right) is eliminated, and the earthquake resistance is improved. Accordingly, in the case of a device that incorporates a component that generates vibration, for example, a notification device (such as a buzzer), the movement of the printed wiring board 1 due to the vibration-generating component causes the printed wiring board 1 to contact the housing. Bilting disappears. Further, when a connector is attached to the printed wiring board 1 and a lead wire is joined thereto from the outside, the connector does not move, so that the joining operation is performed smoothly. Further, since the rattling of the printed wiring board 1 is eliminated, the pressing amount of the pressing portion 131 can be reduced, and the warpage stress of the printed wiring board 1 can be reduced.

Next, a printed wiring board holding structure according to a second embodiment of the present invention will be described with reference to the drawings.

FIGS. 2A and 2B are structural views showing a printed wiring board holding structure according to a second embodiment of the present invention, wherein FIG. 2A is a cross-sectional view showing the printed wiring board holding structure, and FIG. ,
(C) is a plan view of the mounting surface, and (d) is a layout diagram of the mounting surface. FIG. 3 is a structural view of the unevenness of the printed wiring board 2, and FIG.
Is a side view, (b) is an enlarged view of a portion C, and (c) is a plan view.

A resin housing for protecting the printed wiring board 2 on which electronic components and the like are mounted is formed into a square box shape by injection molding, and is divided into a main body portion 12 and a lid portion 13 so as to be separated from each other. Is held so as to be sandwiched.

The main body 12 has a mounting portion 121 on which the printed wiring board 2 is mounted and an engagement hole 123.
The mounting portion 121 supports the printed wiring board 2 from below, and is provided with a plurality of mounting portions along the inner wall of the main body portion 12. A plurality of grooves extending in the same direction are formed on the mounting surface 222 of the mounting portion 121 that is in contact with the printed wiring board 2 for each of the mounting surfaces. The extending directions are orthogonal to each other (FIG. 2D) (at least all the mounting surfaces need not extend in the same direction). Engagement hole 12
Reference numeral 3 denotes a plurality of rectangular holes formed near the opening end face of the main body 12 for engaging the main body 12 and the lid 13.

The cover 13 has a pressing portion 131 and an engaging claw 1.
33 are provided. The pressing portion 131 is mounted on the placing portion 121.
The printed wiring board 2 supported from below is pressed down and held from above, and a plurality of the printed wiring boards 2 are projected from the wall end surface of the lid 13. In addition, the engagement claw 133 is
3 is provided near the end face of the opening and has a gradient shape such that the width of protrusion from the side wall surface increases from the opening side to the bottom of the lid 13, and the number corresponding to the position corresponding to the engagement hole 123 is provided. ing. The printed wiring board 2 is large enough to have a slight clearance with the inner wall of the main body 12 in its outer dimensions. A plurality of projections 55 extending in the same direction as the grooves of the mounting surface 222 extend are provided on the surface of the printed wiring board 2 that contacts the mounting surface 222. The projections are composed of an oblong copper pattern land 551 generated in the printed wiring board manufacturing process and solder 552 welded to the pattern land 551 in the soldering process of the mounted component (FIG. 3B).

Next, an operation of assembling the printed wiring board holding structure will be described. First, the electronic component and the like are mounted on the main body 12 through the upper opening of the printed wiring board 2. Then, the main body 12 is fitted into the main body 12 with the opening side of the lid 13 facing downward, and the plurality of engaging claws 133 are
Push until it engages. Then, the pressing portion 1 of the lid 13
31 pushes down the upper surface of the printed wiring board 1 which rests on the mounting portion 13 of the body portion 12 and is stationary. Thereby, the upper surface of the printed wiring board 2 is pressed by the pressing portion 131 and is fixed at a predetermined position.

As described above, also in the second embodiment, the grooves of the mounting surface 222 at a plurality of positions engage with the protrusions 55 of the contact portions of the printed wiring board 2, so that the printed wiring board 2 The rattling in the directions (front, rear, left and right) is eliminated, and the earthquake resistance is improved. Therefore, in the case of a device having a built-in component that generates vibration, for example, a notification device (such as a buzzer), the vibration generated by the vibration-generating component causes the printed wiring board 2 to come into contact with the housing. Disappears.
Further, since the rattling of the printed wiring board 2 is eliminated, the pressing amount of the pressing portion 131 can be reduced, and the warpage stress of the printed wiring board 2 can be reduced. Moreover, the projections 55 are generated in a conventional manufacturing process, and do not increase the cost. Further, since the extending directions of the grooves of each mounting surface 222 are not all the same, it is possible to suppress the movement of the printed wiring board 2 in all of the front, rear, left and right directions in the horizontal direction.

Next, a third embodiment of the present invention will be described with reference to FIG.

FIGS. 4A and 4B are structural views of the unevenness of the printed wiring board 3, wherein FIG. 4A is a side view and FIG. 4B is a plan view. The third
This embodiment is different from the second embodiment in that the printed wiring board 2 in the printed wiring board holding structure according to the second embodiment is different from the printed wiring board 2 in the other parts. .

The printed wiring board 3 is large enough to have a slight clearance from the inner wall of the main body 12 in its outer dimensions. The printed wiring board 3 is provided with a plurality of protrusions 56 extending in the same direction as the direction in which the grooves of the mounting surface 222 that abut against extend. The protrusions 56 are formed by using a resin paint for displaying on a printed wiring board or preventing a solder bridge between patterns.

As described above, also in the fourth embodiment, the grooves of the mounting surface 222 at a plurality of locations engage with the protrusions 56 of the contact portions of the printed wiring board 3, so that the printed wiring board 3 The rattling in the directions (front, rear, left and right) is eliminated, and the earthquake resistance is improved. Therefore, in the case of a device having a built-in component that generates vibration, for example, a notification device (such as a buzzer), the vibration caused by the vibration-generating component causes the printed wiring board 3 to come into contact with the housing. Disappears.
Further, since the rattling of the printed wiring board 3 is eliminated, the pressing amount of the pressing portion 131 can be reduced, and the warpage stress of the printed wiring board 3 can be reduced. In addition, the projections 56 are generated in a conventional manufacturing process, and do not increase the cost.

[0031]

As described above, according to the present invention, in the printed wiring board holding structure, the printed wiring board is fixed by a large frictional force with the printed wiring board mounting surface of the housing. The rattling can be prevented.

[Brief description of the drawings]

FIG. 1 is a structural diagram showing a printed wiring board holding structure according to a first embodiment of the present invention.

FIG. 2 is a structural diagram showing a printed wiring board holding structure according to a second embodiment of the present invention.

FIG. 3 is a structural diagram of unevenness of a printed wiring board 2;

FIG. 4 is a structural diagram of unevenness of the printed wiring board 3;

FIG. 5 is an exploded perspective view showing a conventional printed wiring board holding structure.

FIG. 6 is a structural view showing a conventional printed wiring board holding structure.

[Explanation of symbols]

 12, 92 ······ Main body 13 ·············································································································································· I ... Mounting surface 131, 931... Pressing portion 51.

Claims (7)

[Claims] 1. A printed wiring board, a main body having a mounting portion on which the printed wiring board is mounted protruding from an inner wall, and a pressing portion for pressing the printed wiring board against the mounting portion are provided on the inner wall. The printed board holding structure, comprising a protruding lid body, wherein the printed wiring board is sandwiched between the mounting section of the main body section and the pressing section of the lid body section, A printed wiring board holding structure, characterized in that the mounting surface has irregularities. 2. The printed wiring board holding structure according to claim 1, wherein a portion of said printed wiring board which comes into contact with said mounting surface is formed of an elastic member having elasticity. 3. The printed wiring board holding structure according to claim 1, wherein the printed wiring board is provided with irregularities in a portion that comes into contact with the mounting surface. 4. The printed wiring board holding structure according to claim 3, wherein the unevenness formed on the mounting surface and the unevenness formed on the printed wiring board are a plurality of grooves extending in the same direction. 5. The printed wiring board holding structure according to claim 3, wherein the unevenness formed on the printed wiring board is formed by solder for connecting components on the printed wiring board. 6. The printed wiring board holding structure according to claim 3, wherein the irregularities formed on the printed wiring board are formed of a resin coating for printing for display or the like on the printed wiring board. 7. The groove according to claim 4, wherein the groove formed on at least one of the mounting portions is different from the groove formed on another mounting portion in a direction in which the groove extends. Printed wiring board holding structure.