JP2002335313A - Mobile telephone and fixing method for its wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile telephone having an increased mount area for components and excellent shock resistance and to provide a fixing method for its wiring board. SOLUTION: The wiring board 10 placed in a case comprising a front case 30 and a rear case 20 which are fixed to each other is fixed in the case by being pressed to a projection 21 formed integrally with a top of a side wall 20b of the rear case 20 via a buffer member 23 by an elastic member 11 provided to the wiring board 10 and whose tip is fitted to a recessed part 22 provided to the rear case 20. Since the wiring board 10 is not screw-fastened to a screw hole, the mount area of the front side of the wiring board 10 is increased, and since the elastic member 11 is fixed to the wiring board 10 and the rear case 20 at its both ends, no positional deviation is caused to the wiring board 10 even when a lateral shock in parallel with the sides of the wiring board 10 is exerted to the wiring board 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable telephone, and more particularly, to a method for fixing a wiring board in a case of a portable telephone.

[0002]

2. Description of the Related Art Conventionally, a portable telephone has a structure in which a wiring board is sandwiched between a front case and a rear case, and the wiring board is fixed to the case by screws.

FIG. 11 is an exploded perspective view showing an example of a method of fixing a wiring board in such a conventional portable telephone.
10 is a wiring board, 12 is a component, 40 is a screw hole, 20 is a rear case, 41 is a screw hole, and 42 is a screw. Here, description will be made assuming that the wiring board is attached to the rear case, but the same applies to the case where the wiring board is attached to the front case.

In FIG. 1, a screw hole 40 is formed in a wiring board 10, and a component 12 and the like are mounted thereon. The screw hole 4 of the wiring board 10 is also provided in the rear case 20.
A screw hole 41 is provided so as to face 0. After the wiring board 10 is arranged in the rear case 20 and aligned, the screws 42 are inserted into the screw holes 41 or the screw holes 40 to be fixed to the rear case 20 by screws.

[0005]

In a method of fixing a wiring board to a case by screwing, as in the above-mentioned conventional mobile phone, it is necessary to provide a screw hole in the wiring board or the case. There is a problem that the mounting area is reduced, and the number of steps of forming and assembling the wiring board and the case is increased.

Further, since the wiring board is fixed to the case by screwing, when an impact is given to the mobile phone by dropping or the like, the impact is directly transmitted to the wiring board, and this is connected to the mounting component. This is considered to be a cause of defects and missing mounted components.

As a countermeasure against such a failure due to the impact, Japanese Patent Laid-Open Publication No. Hei 11-331333 discloses a method in which shocks at the time of drop are provided by providing buffer members on the upper and lower sides of a wiring board and fixing the wiring board to a case via the buffer members. There has been proposed a method of making it difficult to propagate to a wiring board. However, according to this method, although the impact resistance is improved, the mounting area of the components on the wiring board is further reduced because the buffering members are used on the upper and lower sides of the wiring board and the screws are screwed through this. This means that the number of forming steps also increases.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, increase the mounting area of the built-in board, reduce the number of manufacturing steps, and provide a mobile phone excellent in impact resistance and a method of fixing the wiring board. It is in.

[0009]

In order to achieve the above object, a portable telephone according to the present invention has an elastic member provided on at least one surface of a wiring board and an elastic member provided in a front case or a rear case. A concave portion with which the distal end of the member is engaged is provided, and projections for suppressing are provided at a plurality of locations on the top of the side wall of the front case or the rear case. The tip is pressed and fixed to the projection by an elastic member engaged with the recess.

[0010] Further, a buffer member is provided on the protrusion, and the wiring board is pressed against the protrusion via the buffer member.

In the portable telephone according to the present invention, an elastic member is provided on at least one surface of the wiring board, and a concave portion is provided in the front case or the rear case, in which the tip of the elastic member is engaged. A set of a projection as a stopper and a movable projection urged by an elastic material in a direction contacting the projection is provided at a plurality of locations on the top of the side wall of the front case or the rear case. Is fixed by being pressed against the movable projection by the elastic member having the distal end engaged with the concave portion.

The elastic member is a plate spring, a rubber member, a spring spring, or the like, and the protrusion is formed integrally with the front case or the rear case.

In order to achieve the above object, a method of fixing a wiring board in a mobile phone according to the present invention is a method of fixing a wiring board disposed in a front case or a rear case forming a case to the front case or the rear case. It is assumed that the elastic member whose end is fixed to the protrusion integrally formed on the top of the side wall by the front case or the rear case and the wiring board is pressed and fixed.

Further, the wiring board is pressed against the projection via the buffer member.

Further, in the method for fixing a wiring board in a portable telephone according to the present invention, the wiring board disposed in the front case or the rear case forming the case is integrally formed on the top of the side wall of the front case or the rear case. The movable projection urged to abut the projection as a formed stopper,
An elastic member whose end is fixed at the front case or the rear case and the wiring board is pressed and fixed.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing a main part of a first embodiment of a mobile phone and a method of fixing a wiring board thereof according to the present invention, where 11 is a leaf spring, 20a is an inner bottom surface, and 20b
Is a side wall, 21 is a protrusion, 22 is a concave portion, and portions corresponding to FIG. 11 are denoted by the same reference numerals.

In FIG. 1, the surface of the wiring board 10
A component 12 and the like are mounted, and an elastic member made of metal or plastic, here, a leaf spring 11, is provided at a plurality of locations on the rear side peripheral portion. The inner bottom surface 20a of the rear case 20 has a recess 22 at a position facing the plate spring 11 of the wiring board 10 attached thereto.
Are formed at a plurality of locations on the top of the side wall 20b of the rear case 20, and projections 21 for holding down and fixing the wiring board 10 are formed integrally with the side wall 20b.

In this configuration, the wiring board 10 is placed on the rear case 20, and the tip of each leaf spring 11 provided on the wiring board 10 is fitted to the corresponding recess 22 provided on the inner bottom surface 20 a of the rear case 20. After the position is adjusted so as to be fitted, the wiring board 10 is pushed into the rear case 20 against the projection 21, and the wiring board 10
As a result, it is pressed from the inside of the rear case 20 against the pressing projection 21, and is thereby fixed in the rear case 20.

Referring to FIG. 2, such a fixing method will be described in more detail as a first embodiment of the method for fixing a wiring board according to the present invention. 2 shows a cross section passing through the protrusion 21 in FIG. 1, FIG. 2 (a) shows a state before mounting, FIG. 2 (b) shows a state in the middle of mounting, and FIG. 2 (c). Indicates a state after mounting, respectively, 20c is a recessed portion, 23 is a cushioning member, and portions corresponding to FIG. 1 are denoted by the same reference numerals.

In FIG. 2A, a projection 21 is provided on a top surface of a side wall 20b of the rear case 20, and a front end is formed on the rear case 20.
The side wall 20 b of the rear case 20 is formed integrally with the side wall 20 b so as to protrude inward.
A buffer member 23 is provided fixed to the lower surface of the portion protruding from b. Outside the side wall 20b, there is provided a recess 20c into which the side wall of the front case (not shown) fits. Here, the buffer member 23 is made of, for example, rubber.

As shown, when the wiring board 10 is placed on the rear case 20 with the leaf spring 11 facing the inside of the rear case 20, the tip of the leaf spring 11 is moved to the inner bottom surface 2 of the rear case 20.
0a, the wiring board 10 is positioned on or above the protrusion 21 and is supported by the leaf spring 11. Here, as described with reference to FIG.
The distance d ₂ between the protrusions 21 on the two opposing side walls 20b
Is smaller than the width d ₁ of the wiring board 10.

In this state, the position of the wiring board 10 is adjusted so that the tip of the leaf spring 11 fits into the recess 22 formed in the inner bottom surface 20a of the rear case 20, and then the wiring board 10 is removed. When a load is applied in the direction of arrow A from above and pushed into the rear case 20 against the projection 21, the pushing causes the side wall 20b of the rear case 20 to bulge outward as shown in FIG. Bends,
Accordingly, the projection 21 is inclined. When the wiring board 10 is further pushed in, the above-described bending of the side wall 20b increases and the inclination of the projection 21 increases, and finally, the interval between the opposing projections 21 becomes equal to the width d of the wiring board 10.
₁ (FIG. 1) When the wiring board 10 is
It falls below the projection 21 inside.

As described above, when the wiring board 10 falls into the rear case 20, the pressing force on the projection 21 is released, and the side wall 20b of the rear case 20 is not bent, as shown in FIG. Return to the original state. When the wiring board 10 falls into the rear case 20 as described above, the leaf spring 11 is in a compressed state. Therefore, when the load on the wiring board 10 in the direction of arrow A is released, FIG.
As shown in (c), the repulsive force of the compressed leaf spring 11 tends to lift the wiring board 10 upward, but this is prevented by the projection 21 via the buffer member 23, and the wiring board 10 is lifted. It is pressed against the projection 21 via 23. Thereby, the wiring board 10 is stably fixed in the rear case 20.

As described above, the wiring board 1 is placed in the rear case 20.
After fixing the rear case 2 as shown in FIG.
By attaching the front case 30 to the mobile phone 0, a mobile phone as the first embodiment of the present invention is obtained. In this case, the side wall 30a of the front case 30 fits into the recess 20c formed outside the side wall 20b of the rear case 20, and the lateral fixing of the front case 30 and the rear case 20 is stabilized. .

The front case 30 and the rear case 20 may be fixed to each other by screws. However, as shown in FIG. 4, hooks 20d are provided at a plurality of predetermined positions on the side wall 20b of the rear case 20. The hooks 3 are also provided on the side wall 30a of the front case 30 so as to face the hooks 20d.
0d is provided, and the front case 30 and the rear case 20 are fixed by pushing the hooks 30b of the front case 30 into the rear case 20 so that the hooks 20d and 30b are engaged with each other. It may be.

According to the above-described structure of this embodiment, even if a shock is applied in a direction perpendicular to the surface of the wiring board 10 due to a drop of the mobile phone, the shock is absorbed by the buffer member 23 and the leaf spring 11. Such an impact is caused by the wiring board 1
0, and even if an impact is applied in a direction parallel to the surface of the wiring board 10, the distal end of the leaf spring 11 fits into the concave portion 22 of the inner bottom surface 20 a of the rear case 20. There is no displacement of the substrate 10 in that direction. Therefore, in the wiring board 10, the mounting components 12
The connection failure (FIG. 1) and the lack of mounted components can be avoided.

The leaf spring 11 is a member having elasticity, such as a spring or rubber made of metal or organic material, and its shape is, for example, a plate shape appropriately bent so as to generate elasticity. However, the shape and material can be appropriately determined.

With the above-described configuration, in this embodiment, it is possible to avoid the influence on the wiring board 10 due to an impact, and it is not necessary to perform a step of screwing the wiring board 10. Therefore, steps such as screwing become unnecessary, and the number of working steps can be reduced. Also,
Since the wiring board 10 does not require a portion in which a screw hole is conventionally provided, the mounting area is increased, and the number of components to be mounted can be increased. Furthermore, since the wiring board 10 can be fixed simply by fitting it into the case, the assembly is easier than the conventional mobile phone.
By using a conductive material for the leaf spring 10, it can be used as a ground or a contact point between the antenna and the wiring board 10.

FIG. 5 is a view showing a main part of a second embodiment of a portable telephone and a method of fixing a wiring board thereof according to the present invention, wherein reference numeral 13 denotes a rubber member, which corresponds to FIG. 1 and FIG. Are denoted by the same reference numerals, and redundant description is omitted.

Referring to FIG. 2A, in the second embodiment, a rubber member 13 is used as an elastic member instead of the leaf spring 11 in the first embodiment shown in FIG. . Also in the second embodiment, the inner bottom surface 20a of the rear case 20 is provided with a concave portion 22 into which the tip of the rubber member 13 fits.

The wiring board 10 is positioned by fitting the tip of the rubber member 13 into the recess 22, and a load is applied to the wiring board 10 from above in the direction of arrow A to push the wiring board 10 into the rear case 20. By doing so, the wiring board 10 fits into the rear case 20 through a state similar to the state shown in FIG. At this time, as shown in FIG. 5B, the rubber member 13 is compressed and expanded between the rear case 20 and the wiring board 10, and the repulsive force causes the upper surface of the wiring board 10 to move to the cushioning member 23. Is pressed against the protrusion 21 for holding down. Thereby, the wiring board 10 is stably fixed in the rear case 20.

FIG. 6 is a sectional view showing a second embodiment of the portable telephone according to the present invention obtained by attaching the front case 30 to the rear case 20 to which the wiring board 10 is attached as described above. Parts corresponding to those in FIG. 5 are denoted by the same reference numerals, and the front case 30 and the rear case 3
The method of fixing to 0 is also the same as in the first embodiment.

According to the configuration of the second embodiment, a screwing step of the wiring board 10 is not required, and drilling and screwing in the wiring board 10 are not required, so that the number of working steps is reduced. In addition, since a portion where a screw hole is conventionally provided is not required, the mounting area of the component on the wiring board 10 is increased, and the mounting amount of the component is increased.

Further, even if a shock is applied to the portable telephone due to a drop or the like, the rubber member 13 formed on the wiring board 10 absorbs the shock, so that the shock is hardly transmitted to the wiring board 10 and the rubber member 13 is formed in the rear case. Since the wiring board 10 is fitted into the recess 22, the horizontal movement of the wiring board 10 can be suppressed even if a horizontal impact is applied to the wiring board 10, so that poor connection of the mounted components and missing of the mounted components can be avoided. . The shape and material of the rubber member 13 are not limited as long as the rubber member 13 has an elastic force. Furthermore, since the wiring board 10 can be fixed only by fitting the wiring board 10 into the rear case 20, the assembly is easier than with a conventional mobile phone that is screwed.

FIG. 7 is a view showing a main part of a third embodiment of a portable telephone and a method of fixing a wiring board thereof according to the present invention, wherein 14 is a spring, 24 is a stopper, 25 is an elastic member, and 26 is an elastic member. Portions that are movable projections and correspond to the above-described drawings are denoted by the same reference numerals, and redundant description will be omitted.

In FIG. 3A, a pin-shaped spring having a built-in spring is used as an elastic member for fixing the wiring board 10 in place of the leaf spring 11 of the first embodiment shown in FIG. 14 are provided, and the rear case 20 includes
A recess 22 into which the tip of the spring 14 fits is provided. On the top of the side wall 20b of the rear case 20, a stopper (projection) 24 protruding inside the rear case 20 (similar to the holding projection 21 in FIGS. intervals (corresponding to the distance d ₂ in FIG. 1) the width d ₁ of the wiring board 10 (Fig. 1)
Is formed integrally with the side wall 20b, and a movable projection 26 is provided on the lower surface so as to be able to abut. The tip of the movable projection 26 projects further than the tip of the stopper 24, and the distance between the opposed movable projections 26 (FIG. 1)
Corresponds to the distance d ₂ in) is set narrower than the width d ₁ of the wiring board, also the inner surface of the side wall 20b, side walls 20
It is attached to the inner surface of b by means such as a hinge (not shown) so as to be rotatable in the vertical direction (the directions of arrows B and B 'shown in the figure) (this attachment point is P). This movable projection 2
6 is pressed against the lower surface of the stopper 24 by an elastic member 25 such as a spring until the wiring board 10 is fitted into the rear case 20.

FIG. 8 is a sectional view showing a specific example of the structure of the spring 14 shown in FIG. 7, in which 14a is a storage portion, 14b is a compression spring, 14c is an engagement member, and 14d is a mounting portion.

In the same figure, the mounting portion 14d is
0 (FIG. 7).
A cylindrical storage portion 14a is fixed to d, and a compression spring 14b is stored in the storage portion 14a. One end of the compression spring 14b is fixed in the storage portion 14a,
An engaging member 14c is attached to the other end. here,
The elastic force and length of the compression spring 14a are set such that a part of the engagement member 14c is fitted into the storage portion 14a even if the compression spring 14b is fully extended due to the weight of the engagement member 14c. ing.

In FIG. 7A, when the wiring board 10 is positioned by fitting the tip of the spring 14 (the tip of the engaging member 14c (FIG. 8)) into the concave portion 22, the wiring board 10 Or above the wiring board 10 in this state.
When a load is applied in the direction of arrow A from above and lowered,
As shown in FIG. 7B, the movable protrusion 26 is pressed by the movable protrusion 26 and rotates downward, that is, in the direction of arrow B, against the elastic force of the elastic member 25. At the same time, the elastic member 25 is compressed and bent. Thereby, the wiring board 10 can be pushed into the rear case 20. In the spring 14, as shown in FIG. 8, as the wiring board 10 descends, the engaging member 14c enters the housing portion 14a against the elastic force of the compression spring 14b.

In FIG. 7B, as the wiring board 10 is pushed in the direction of arrow A, the springs 14 are compressed, and finally, the opposing rotated movable projection 26 is turned on.
When distance becomes the width d ₁ or more wiring board 10 by its rotation, as shown in FIG. 7 (c), the state is the wiring board 10 fitted in the rear case 20. In such a state, the movable protrusion 26 is disengaged from the wiring board 10, and is turned upward by the elastic force of the elastic member 25, that is, turned in the direction of the arrow B ′ to come into contact with the lower surface of the stopper 24. I have. Then, when the load on the wiring board 10 is released, the wiring board 10 is lifted by the repulsive force of the compressed spring spring 14 and comes into contact with the lower surface of the movable projection 26. At this time, since the movable protrusion 26 is supported by the stopper 24, the wiring board 10 is stabilized by the spring spring 14 while being pressed against the movable protrusion 26. As a result, the wiring board 10 is
It is fixed stably within 0.

FIG. 9 is a sectional view showing a third embodiment of the portable telephone according to the present invention obtained by attaching the front case 30 to the rear case 20 to which the wiring board 10 is attached as described above. The parts corresponding to those in FIG. 7 are denoted by the same reference numerals, and the front case 30 and the rear case 3
The method of fixing to 0 is also the same as in the first embodiment.

With this configuration of the third embodiment,
The step of screwing the wiring board 10 is not required, and the wiring board 10
No drilling or screwing is required, reducing the number of working steps. In addition, since a portion where a screw hole is conventionally provided is not required, a mounting area on the wiring board 10 is increased, and a mounting amount of components is increased.

Further, even if a shock is applied to the portable telephone due to a fall or the like, the spring spring 14 provided on the wiring board 10 is provided.
Absorbs this impact, so that the impact is hardly transmitted to the wiring board 10, and the springs 14 are fitted into the recesses 22 provided in the rear case 20, so that the wiring board 10
Therefore, even if a horizontal force is generated, the horizontal movement of the wiring board 10 is suppressed, and it is possible to avoid poor connection of the mounted components and omission of the mounted components.

The shape and material of the spring 14 are not limited as long as it is an elastic member made of metal or organic material. In the third embodiment, another elastic member such as the leaf spring 11 as shown in FIG. 2 or the rubber member 13 as shown in FIG. 5 may be used in place of the spring 14. . Similarly, in the first embodiment shown in FIG. 2 and the second embodiment shown in FIG. 5, another elastic member such as the spring 14 shown in FIGS. It may be used.

Since the wiring board 10 can be fixed only by fitting the wiring board 10 into the rear case 20,
Assembly is also easier than with conventional mobile phones that are fixed by screws. Further, by using the movable projection 26 on the rear case 20 side, the load when the wiring board 10 is fitted into the rear case 20 can be reduced, and the rear case 20 does not deform when fitted. Wiring board 10
Will be reduced. Further, by using a conductive material as the spring 14, it can be used as a ground or a contact point between the antenna and the wiring board 10.

In each of the above embodiments, the wiring board 10
Is attached to the rear case 20, but may be attached to the front case 30. As the fixing method at this time, the method described above can be employed.

In each of the above embodiments, the elastic members (the leaf springs 11, the rubber members 13, and the springs 14) are provided on the wiring board 10, but either the rear case 20 or the front case 10 is provided. Or you may make it provide in both. FIG. 10 shows an elastic member (for example, leaf spring 1).
1) shows a case in which the rear case 20 is provided.
In this case, the wiring board 10 is provided with a recess 15 into which the tip of the elastic member 11 fits.

[0048]

As described above, according to the present invention,
The effect of increasing the mounting area on the wiring board, reducing the number of processes, improving impact resistance, etc. can be obtained, and does not require the addition of new equipment on the production line. It does not require.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a main part of a first embodiment of a mobile phone and a method of fixing a wiring board thereof according to the present invention.

FIG. 2 is a cross-sectional view showing a specific example of a method of attaching a wiring board to a rear case in the first embodiment shown in FIG.

FIG. 3 is a cross-sectional view showing a state in which a front case is attached to a rear case to which a wiring board is attached by the method shown in FIG. 2;

FIG. 4 is a view showing a specific example of a fixing means for fixing the rear case and the front case in FIG. 3;

FIG. 5 is a cross-sectional view showing a specific example of a method of attaching a wiring board to a rear case in a second embodiment of a mobile phone and a method of fixing the wiring board according to the present invention.

6 is a sectional view showing a state in which a front case is attached to a rear case to which a wiring board is attached by the method shown in FIG. 5;

FIG. 7 is a cross-sectional view showing a specific example of a method of attaching a wiring board to a rear case in a third embodiment of a mobile phone and a method of fixing the wiring board according to the present invention.

FIG. 8 is a sectional view showing a specific example of a spring in FIG. 7;

9 is a sectional view showing a state in which a front case is attached to a rear case to which a wiring board is attached by the method shown in FIG. 7;

FIG. 10 is a cross-sectional view showing a specific example of a method of attaching a wiring board to a rear case in a fourth embodiment of a mobile phone and a method of fixing the wiring board according to the present invention.

FIG. 11 is a perspective view showing a state where a wiring board is mounted on a rear case of a conventional mobile phone.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Wiring board 11 Leaf spring 12 Mounting component 13 Rubber member 14 Spring spring 14a Storage part 14b Compression spring 14c Engagement member 15 Depression 20 Rear case 20a Inner bottom surface 20b Side wall 20c Depression 21 Protrusion 22 Recess 23 Buffer member 24 Stopper 25 Elastic member 26 Movable projection 30 Front case 30a Side wall

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuji Fujita 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Hitachi, Ltd. Production Technology Research Institute (72) Inventor Masato Nakamura 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd., Production Technology Laboratory (72) Inventor Tomoko Yoda 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term in Hitachi, Ltd. Production Technology Laboratory 5E348 AA11 AA13 CC08 EE32 5K023 AA07 BB04 LL01 LL06 PP02 RR08

Claims (10)

[Claims] 1. A mobile phone in which a wiring board is disposed in a case in which a front case and a rear case are fixed, wherein an elastic member is provided on at least one surface of the wiring board and the front case is provided. Alternatively, in the rear case, a concave portion is provided in which the distal end of the elastic member is engaged, and a plurality of projections for suppressing are provided at a plurality of locations on the top of the side wall of the front case or the rear case. A mobile phone, wherein the wiring board accommodated in a part case or the rear case is fixed by being pressed against the protrusion by the elastic member having a tip part engaged with the concave part. 2. The mobile phone according to claim 1, wherein a buffer member is provided on the protrusion, and the wiring board is pressed against the protrusion via the buffer member. 3. A mobile phone in which a wiring board is disposed in a case in which a front case and a rear case are fixed, wherein an elastic member is provided on at least one surface of the wiring board and the front case is provided. Alternatively, a concave portion is provided in the rear case to which the distal end of the elastic member is engaged, and a plurality of protrusions serving as stoppers and the protrusions are provided at a plurality of locations on the top of the side wall of the front case or the rear case. A pair of movable projections biased by an elastic material in a contacting direction is provided, and the wiring board housed in the front case or the rear case is formed by the elastic member having a front end engaged with the recess. A mobile phone, which is fixed by being pressed against the movable projection. 4. The mobile phone according to claim 1, wherein the elastic member is a leaf spring. 5. The mobile phone according to claim 1, wherein the elastic member is a rubber member. 6. The mobile phone according to claim 1, wherein the elastic member is a spring. 7. The mobile phone according to claim 1, wherein the projection is formed integrally with the front case or the rear case. 8. A method of fixing a wiring board in a case of a mobile phone, comprising: mounting the wiring board in a front case or a rear case forming the case with the wiring case of the front case or the rear case. A method of fixing a wiring board, characterized in that an elastic member whose end is fixed by the front case or the rear case and the wiring board is fixed to a projection integrally formed on the top of the side wall. . 9. The method according to claim 1, wherein the wiring substrate is pressed against the protrusion via a buffer member. 10. A method of fixing a wiring board in a case of a mobile phone, wherein the wiring board arranged in a front case or a rear case forming the case is attached to the front case or the rear case. An elastic member whose end is fixed by the front case or the rear case and the wiring board to a movable projection urged to contact a projection as a stopper integrally formed on the top of the side wall. A method for fixing a wiring board, wherein the wiring board is fixed by pressing.