JP2002291195A - Electromagnetic vibrator and portable electronic device equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a further reliable cellular phone by solving the problem that the metallic cover is peeled from a motor or the printed circuit board of the cellular phone due to dropped impact in the cellular phone (portion electronic equipment) using a vibration motor (an electromagnetic oscillator). SOLUTION: The motor has a base 11 that allows a metal piece 13 to be subjected to insert molding for retaining and is made of resin, and the metallic cover 21 that covers the base 11. In the cover 21, a tab 22 provided at one end of the cover 21 is bent to the bottom surface side from the side of the base 11 for engaging and sticking to the metal piece 13 of the base.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic vibrator in a portable electronic device, and more particularly, to a technique for improving strength and reliability against a drop impact.

[0002]

2. Description of the Related Art Portable electronic devices are continually being improved with the aim of reducing size and weight and increasing productivity. For example, in a mobile phone, for example, an electromagnetic vibrating body (vibration motor) for vibration notification has conventionally been pressed against a main body printed circuit board of an apparatus by using an elastic body to be electrically connected. On the other hand, Japanese Patent Application Laid-Open No. 2000-189893 by the present applicant discloses an invention in which a vibration motor (hereinafter, also simply referred to as a motor) is surface-mounted on a mobile phone.

[0003] Although this technique has greatly reduced the weight and productivity, it may be disadvantageous due to the introduction of the new technology. For example, when the conventional pressing elastic body is abolished at the same time as the surface mounting of this motor, there is a possibility that the dropping shock may cause inconvenience such as the motor being destroyed or the surface mounting part being peeled off. This motor has a structure in which the internal components are covered with a metal cover, and components having a large mass such as a tungsten weight are incorporated therein. Attachment of such a heavy electronic component only by surface mounting is new and has a poor track record. In order to deal with this problem, the invention disclosed in the above publication discloses FIG.
As shown in (1), a solder fillet 966 is formed by the main body land 962 and the protrusion 959. That is, the solder area is set to the metal surface 94 perpendicular to the back surface terminal (such as 928 in the figure)
9, a large area is secured, and the cover 944 is prevented from peeling off from the motor printed board 941 or the main body printed board 99. Since this structure uses the vertical metal surface 949, the area of the substrate is not consumed, and therefore, there is an advantage that the bonding strength is secured and the mounting area efficiency of the main body printed board 99 can be maintained high.

In recent years, the rejection of solder containing lead has been called out, and the industry is working diligently to develop alternative technologies.
It is considered that a method using Sn-Cu-based or Sn-Ag-based lead-free solder is effective from a comprehensive viewpoint, and replacement with this solder has begun. However, these solders have a higher melting point than conventional solders. For this reason, there has been a problem that the electronic component is exposed to a higher temperature for a longer period of time than before, and the surface of the terminal is oxidized to deteriorate the solder wettability. Also in the motor having the above-described structure, the solder wettability deteriorates on the metal surface 949 of the cover 944 in the mounting process employing lead-free solder.
44 may be peeled off from the motor printed board 941 or the main body printed board 99 in some cases. The above publication states that the cover 944 has a tin-plated coating to improve the wettability of the solder.
Although a proposal to apply gold plating or the like has been shown, there has been a fundamental demand for a more reliable structure that does not rely on the wettability of the vertical metal surface 949.

[0005]

As described above, the present invention relates to a portable electronic device equipped with an electromagnetic vibrator, in which the metal cover of the electromagnetic vibrator is peeled off from the main body of the electromagnetic vibrator by a drop impact, or the portable electronic device is mounted. An object of the present invention is to solve a problem such as peeling off from a main body printed circuit board of a device and to obtain a portable electronic device having higher impact resistance and higher reliability.

[0006]

In order to achieve the above object, the present invention comprises an insulating base for exposing and holding a soldered terminal on the bottom side, and a metal cover for covering the same. One end is bent from the side surface of the base to the bottom surface side and fixed to the base, or an insulative base that exposes and holds the soldering terminals to the bottom surface and a metal cover that covers the base. The cover is provided with a tab extending to the bottom surface side of the base, and the tab is bent from the side surface of the base to the bottom surface side and fixed to the base, or a metal piece is inserted. A resin base for molding and holding, and a metal cover for covering the resin base, the cover being bent at one end from the side surface of the base to the bottom surface side to engage and fix to the metal piece of the base. Is shall.

[0007]

In order to achieve the above object, an electromagnetic vibrator according to a first aspect of the present invention comprises an insulating base for exposing and holding a soldering terminal on a bottom side, and a metal cover for covering the insulating base. And a cover fixed to the base by bending one end of the cover from the side surface of the base to the bottom surface.

[0008] Since the cover is directly engaged with and held by the base at one end thereof, the cover can be held with a force larger than the strength at the time when the cover is joined to the vertical surface of the cover by soldering. Therefore, it is possible to prevent the fixed portion of the cover from being broken by the drop impact force.

According to a second aspect of the present invention, there is provided an electromagnetic vibrator,
It has an insulating base that exposes and holds the soldering terminals on the bottom side and a metal cover that covers the base. The cover has tabs that extend to the bottom side of the base, and the tabs are bent from the side surfaces of the base to the bottom side And stick to the base.

The tab fits in a small space, has a large engaging and holding force, and is easy to bend. Therefore, a sufficient engaging and fixing force is exhibited particularly in a small and large electronic component. Therefore, it is possible to prevent the electronic component having a large mass from being destroyed by a drop impact.

According to a third aspect of the present invention, there is provided an electromagnetic vibrator,
It has a resin base for insert-molding and holding a metal piece and a metal cover for covering the metal piece, and the cover is fixedly engaged with the metal piece of the base by bending one end of the base from the side surface of the base to the bottom surface.

As a result, the mechanical strength of the portion where the cover engages can be increased, and the load capability against a drop impact force can be increased in an electronic component having a large mass. Therefore, the drop impact reliability of the device is further improved.

[0013] The electromagnetic vibrator according to claim 4 of the present invention comprises:
The lower end of the bent tab is substantially the same height as the bottom surface of the base or slightly protrudes. This enables solder joining between the tab and the main body printed circuit board, and the tab can be surface-bonded not only to the cover with the base but also to the main body printed circuit board. Therefore, the drop impact reliability of the device is further improved.

According to a fifth aspect of the present invention, there is provided an electromagnetic vibrator,
The tabs are gold plated. As a result, the solder wettability of the tab is improved, and the reliability of soldering between the tab and the main body printed circuit board is improved. Therefore, the drop impact reliability of the device is further improved.

A portable electronic device according to a sixth aspect of the present invention includes the electromagnetic vibrating body according to any one of the first to fifth aspects. Since the cover is engaged and held on the base, the holding force of the cover can be increased. Therefore, the drop impact reliability of the device is improved. Further, since the cover is held by both the base and the main body printed circuit board, the holding force of the cover can be further increased. Therefore, the drop impact reliability of the device is further improved.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) The present invention is suitable for application to an electromagnetic vibrator using a motor. An example in which the present invention is applied to a motor will be described below. FIGS. 1A and 1B show the appearance of a motor according to a first embodiment of the present invention, wherein FIG.
(B) is a side view, and (c) is a bottom view. FIG.
Shows an example in which this motor is mounted on a mobile phone. FIG. 3 is a cross-sectional side view showing the structure of the motor, which is cut at a position indicated by an arrow shown in FIG.

Referring to FIG. 1, the motor includes a base 11 and a cover 21. The base 11 is made of a resin molded product having a polygonal (substantially decagonal) planar shape, and has six soldering terminals 12 on the bottom surface. Soldering terminal 1
2 is insert-molded on the base 11 and the soldering surface is exposed on the bottom side. The cover 11 covers the base 11. The cover 21 has a circular cup shape, and its open end is in contact with the outer peripheral edge of the base 11. There are six tabs 22 at the open end of the cover 21 and extend to the bottom side of the base 11. The appearance of the motor as a whole has a flat cylindrical shape.

FIG. 2 shows a portable telephone equipped with this motor. In FIG. 2, a main body printed circuit board 72 is provided inside a housing 71 of a mobile phone (hereinafter also simply referred to as a device), and most of electronic components used in the device are mounted. The vibration notification motor 73 according to the present embodiment is also mounted together with the control IC 74 for driving the motor. At this time, the motor 73 is mounted on the main body printed board 72 by surface mounting, and no holding means such as pressing and holding the motor 73 is employed. Further, a battery 75 is fitted in a part of the housing, so that the device can be carried and used.

The internal structure of the motor will be described with reference to FIG. FIG. 3 is a side cross-sectional view of the motor cut at a position indicated by an arrow shown in FIG. In FIG. 3, the motor includes a base 11 having insert-molded soldering terminals 12 and metal pieces 13, a stator winding assembly 14 attached thereto,
It is composed of a ring-shaped magnet 15 facing the outer periphery, a rotor frame 16 for housing and holding the same, a shaft 17 serving as a rotation center thereof, a bearing 18 for supporting the shaft, and the like. An eccentric weight 19 made of a tungsten material is fixed to the inside of the rotor frame 16. The cover 21 covers them, and functions to prevent the rotor frame 16 from falling off, prevent foreign substances from entering the inside of the motor, improve the handleability when mounting, and prevent hot air from entering during reflow heating.

A tab 22 is provided on the end face of the cover 21.
Is provided. The tab 22 is bent from the side surface of the base 11 to the bottom surface side. At this time, the base 11 is provided with a concave portion 11a formed by cutting out a resin in a portion for accommodating the tab 22, and the metal piece 13 is exposed there. Therefore tab 2
2 is directly engaged with the metal piece 13. The tab 22 does not protrude from the bottom of the base. On the other hand, the solder terminal 12 inserted into the base 11 is formed so as to slightly protrude from the bottom surface of the base. Therefore, when this motor is surface-mounted on the main body printed circuit board 72, the motor is held by the solder terminals 12.

The motor thus configured is mounted and connected to the lands of the main body printed circuit board 72, and is energized to the stator winding assembly 14 via the solder terminals 12. As a result, the magnet 15 is driven to rotate, and vibration is generated by the eccentric weight 19 attached to the rotor frame 16, so that the mobile phone can be notified of the vibration.

As described above, in the motor of the present embodiment, one end of the metal cover 21 is bent from the side surface of the base 11 to the bottom surface and is fixed to the base 11. The cover 21 is directly engaged with and held by the base 11 at one end thereof.
Can be held with higher strength than when joined by solder on the vertical surface of the cover as in the conventional example. Therefore, it is possible to prevent the cover from dropping and breaking when a drop impact force is applied to the motor.

In the motor of the present embodiment, the metal cover 21 is provided with a tab 22 extending toward the bottom surface of the base 11.
The tab 22 is fixed to the base 11 by bending the tab 22 from the side surface to the bottom surface side. The tab 22 fits in a small space, has a large engaging and holding force, and is easy to bend. Therefore, a sufficient engaging and fixing force is exhibited particularly in a small and large electronic component. Therefore, it is possible to prevent the electronic component having a large mass from being destroyed by a drop impact.

In the motor of this embodiment, the cover 21 has one end bent from the side surface of the base 11 to the bottom surface.
The first metal piece 13 is engaged and fixed. This can increase the mechanical strength of the portion where the cover 21 engages,
It is possible to increase the load capability against a drop impact force in an electronic component that is extremely small but has a large mass. Therefore, the drop impact reliability of the device is further improved.

(Embodiment 2) Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4A is a partially enlarged cross-sectional view of the same, and FIG. In the motor of FIG. 4, other members except for the cover 212 are the same as those described in the first embodiment, and a description thereof will be omitted.

A tab 222 is provided on the cover 212 in the same manner as in the first embodiment.
It is bent and housed. There is a metal strip 13 with a tab 222 engaged therewith. However, the lower end surface of the tab 222 slightly protrudes from the bottom surface of the base 11.
The surface of the tab 222 is plated with gold. And the land of the main body printed board 72 (not explicitly shown)
Is fixed by solder 76. Although not shown, the motor and the main body printed board are also fixed at solder terminals.

As described above, in the motor according to the present embodiment, the lower end of the bent tab 222 is substantially the same height as the bottom surface of the base 11 or slightly protrudes. This allows the tab 22
2 and the main body printed board 72 can be soldered,
The tab 222 not only connects the cover 212 to the base 11 but also makes a surface connection with the main body printed circuit board 72. Further, the solder 76 attached to the tab 222 has an action of improving the bending rigidity of the tab. Therefore, the drop impact reliability of the device is further improved.

The motor of this embodiment is formed by plating the tab 222 with gold. Thereby, the solder wettability of the tab 222 is improved, and the reliability of soldering between the tab 222 and the main body printed circuit board 72 is enhanced. Therefore, the drop impact reliability of the device is further improved.

(Embodiment 3) Next, a third embodiment of the present invention will be described with reference to FIG. In the motor of this embodiment, one end of the metal cover is fixed to the base by bending one end of the cover from the side surface of the base to the bottom surface. FIG. 5A is a partially enlarged cross-sectional view thereof, and FIG. 5B is a partially enlarged view of the same viewed from the lower surface side. In the motor shown in FIG. 5, the other members except for the cover 213 are the same as those described in the first embodiment, and a description thereof will be omitted.

The cover 213 has a bridge 223 instead of the tab 22 in the first embodiment. In order to form a bridge, a rectangular slit 233 is provided (only the cross-sectional shape is drawn in the figure). Then, the bridge 223 on the lower end side of the slit is deformed and engaged with the concave portion 11a on the bottom surface side of the base to fix the cover and the base. This structure allows the engagement of the bridge 223
Is deformed in the radial direction, so that the height accuracy after bending is easily maintained.

While several embodiments have been described above,
Needless to say, the present invention is not limited to the above embodiment, and various applications and developments are possible within the scope of the present invention. Although it can be applied to various electromagnetic vibrators, it is particularly suitable for use in electromagnetic vibrators having relatively large mass and surface mount type motors. In the embodiment, only the terminal provided with the soldering terminal inside the base is shown, but the terminal whose terminal is directed outward in a gull wing shape is also within the applicable range of the present invention. The mating member with which the cover is engaged may be a resin portion of the base. In the text, “the bottom side of the cover” refers to the surface on which the soldering terminals are provided, and if the soldering terminals are provided on a plurality of surfaces, any of the surfaces is the bottom surface. Further, in the above-mentioned embodiment, a bendable tab or bridge is formed on the end face of the cover. However, it is also within the scope of the present invention to simply bend one end and fix and engage without providing such a thing. When the mass is relatively small, this can also achieve the purpose sufficiently.

[0033]

As described above, according to the present invention, in a portable electronic device equipped with an electromagnetic vibrating body, the metal cover of the electromagnetic vibrating body is peeled off from the main body of the electromagnetic vibrating body by a drop impact, or the portable electronic device has It is possible to solve a problem such as peeling off from the main body printed circuit board, and to obtain a portable electronic device having higher impact resistance and higher reliability.

[Brief description of the drawings]

FIG. 1A is a top view showing the appearance of a motor according to a first embodiment of the present invention, FIG. 1B is a side view thereof, and FIG.

FIG. 2 is a diagram showing an example in which the motor according to the first embodiment of the present invention is mounted on a mobile phone.

FIG. 3 is a side sectional view showing the structure of the motor according to the first embodiment of the present invention.

FIG. 4A is a partially enlarged cross-sectional view showing the structure of a motor according to a second embodiment of the present invention. FIG.

FIG. 5 (a) is a partially enlarged sectional view showing the structure of a motor according to a third embodiment of the present invention, and (b) is a partially enlarged view as viewed from the lower surface side.

FIG. 6 is a sectional view showing the structure of a conventional motor.

[Explanation of symbols]

 Reference Signs List 11 base 11a recess cut out of resin 12 soldering terminal 13 metal piece 21, 212, 213 cover 22, 222 tab 223 bridge 233 rectangular slit 71 mobile phone (portable electronic device) housing 72 main body printed circuit board 73 motor ( Electromagnetic vibrator) 74 Control IC 75 Battery 76 Solder

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideo Kobayashi 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Masafumi Kumo 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. (reference) AA07 BB26 BB27 HH04

Claims (6)

[Claims] An insulating base for exposing and holding the soldering terminal on the bottom side; and a metal cover for covering the insulating base. The cover is formed by bending one end of the cover from a side surface of the base to the bottom side. An electromagnetic vibrator fixed to the base. 2. A base comprising: an insulating base for exposing and holding a soldering terminal on a bottom side; and a metal cover for covering the insulating base. The cover includes a tab extending to the bottom side of the base. An electromagnetic vibrator, which is bent from a side surface of the base toward the bottom surface and is fixed to the base. 3. A resin base for insert-molding and holding a metal piece, and a metal cover for covering the metal piece, wherein the cover has one end bent from the side surface of the base to the bottom surface to form the metal cover. An electromagnetic vibrating body fixedly engaged with a piece. 4. The lower end of the bent tab is substantially flush with or slightly protrudes from the bottom surface of the base.
Electromagnetic vibrator as described. 5. The electromagnetic vibrator according to claim 4, wherein the tab is gold-plated. 6. A portable electronic device on which the electromagnetic vibrator according to claim 1 is mounted.