JPH11277648A - Casing, and casing for portable telephone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve rigidity with a thinner wall and a lighter weight than those of a casing obtained by a single resin molded product without using a reinforced resin material or metal material filled with glass fiber, carbon fiber or the like. SOLUTION: This casing is used for an application required for a thickness of a predetermined value or more at the time of constituting by only a first material. In this case, the casing comprises a base material 1 made of the first material, a first metal plated layer 2 laminated on the material 1, and a second metal plated layer 3. The casing is thinner and lighter and those of that constituted by only the first material with rigidity equivalent or more thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casing made of a material obtained by laminating two or more different kinds of materials, and particularly to a casing for a portable telephone.

[0002]

2. Description of the Related Art In recent years, there has been a demand for smaller and lighter housings for housing portable information terminals and electronic devices.
A resin housing made of a resin molded product is widely used.

However, in order to further reduce the size and weight, it is necessary to reduce the thickness of the resin housing. However, if the conventional resin is used as it is, the thickness of the resin housing becomes thin. There is a problem in that the flexural rigidity and the impact property decrease with the development.

For this reason, it is necessary to newly use a casing material which does not decrease rigidity or impact resistance even when the resin casing is made thinner. To this end, it is necessary to secure the rigidity of the conventional resin casing. However, a material having a flexural modulus superior to that of the conventional housing material must be selected.

[0005] Therefore, as a method of increasing the rigidity of the housing and making it thinner and lighter, it is known to use a reinforced resin material or a metal material filled with glass fiber, carbon fiber, or the like as the housing material. JP-A-7-60777).
Further, there is known an electromagnetic wave shielding material in which strength is improved by laminating a thin steel sheet on at least one surface of an insulating sheet or a conductive sheet via an adhesive (Japanese Utility Model Application Laid-Open No. 62-6249).
No. 8).

Further, in a case using the above-mentioned reinforcing material, when the reinforcing material alone cannot secure sufficient rigidity, and when the strength is still insufficient only by the thickness of the resin molded product, the strength of the molded product is reduced. In some cases, a reinforcing rib is partially provided on the back surface of the decorative surface.

[0007]

However, the case where a housing material is made of a reinforced resin material filled with glass fiber or carbon fiber or the like (Japanese Patent Laid-Open No. 7-60777),
During molding, the fluidity is poor, and it is difficult to form a thin and complex shape. In addition, since the reinforced resin material has a lower breaking strain than that of the base resin alone and has a brittle property, there is a problem that the impact strength is reduced. Further, since the weight of the reinforced resin material is increased by the amount of the filled fiber, it is difficult to reduce the weight, and the material cost is high.

Further, a thin sheet laminated on an insulating sheet or a conductive sheet via an adhesive (Japanese Utility Model Application Laid-Open No. 62-624).
No. 98), only a simple shape can be applied, but a complicated shape cannot be applied, and there is a problem that a thin steel sheet is easily wrinkled. Further, simply laminating thin steel sheets may increase the weight, and it is necessary to define an appropriate thickness.

Further, with respect to the ribs provided for securing the rigidity of the resin housing, sink marks tend to occur on the surface side where the ribs are provided, and if they occur on the decorative surface, the texture of the product deteriorates. Further, when the ribs are provided, the thickness increases, which is a problem in downsizing.

When a metal is formed by die-casting to form a housing, a thin-walled one has poor moldability and remarkably generates burrs. Removal of the burrs requires human labor, which reduces productivity, makes mass production difficult, and significantly increases costs.

According to the present invention, a thinner, lighter, and more rigid body is obtained than a housing obtained from a resin molded product alone without using a reinforced resin material or a metal material filled with glass fibers or carbon fibers. An object of the present invention is to provide a housing, particularly a mobile phone housing.

[0012]

The present invention has the following arrangement to achieve the above object. The casing according to claim 1 is a casing used for an application requiring a thickness not less than a predetermined thickness when the casing is made of only the first material,
A substrate made of a material, and at least one layer laminated on the substrate and made of at least one kind of material different from the first material;
And a cover which is thinner, has a smaller weight, and has a rigidity equal to or greater than that of the case constituted by only the first material.

[0013] housing according to claim 2, when composed of only the first material, a housing for use in applications where the thickness t _p is required, a base made of a first material And an n-layer (n ≧ 1) coating body laminated on both surfaces of the base material and made of at least one kind of material different from the base material, wherein the thickness of the base material is t ₀ , density ρ ₀ , flexural modulus E
₀ and the i-th layer of the coating (1 ≦ i ≦ n)
Is (t _i −t _i−1 ) / 2, the density is ρ _i , and the flexural modulus is E _i ,

[0014]

(Equation 1)

A housing characterized by satisfying the above formulas (1A) to (1C).

The housing of claim 3, when composed of only the first material, a housing for use in applications where the thickness t _p is required, a base made of a first material An n-layer (n ≧ 1) covering body laminated on only one surface of the base material and made of at least one kind of material different from the base material, wherein the thickness of the base material is t ₀ , the density is ρ ₀ , the flexural modulus is E _0, and the i-th layer (1 ≦ i ≦
n), the thickness is (t _i −t _i−1 ), the density is ρ _i , and the flexural modulus is E _i ,

[0017]

(Equation 2)

A housing characterized by satisfying the above formulas (2A) to (2C).

According to a fourth aspect of the present invention, there is provided the casing according to any one of the first to third aspects, wherein the base and the cover are formed with ribs. Body.

According to a fifth aspect of the present invention, there is provided a mobile phone casing comprising: a base made of a resin; and a cover made of at least one metal plating layer formed on one or both sides of the base. A case for a mobile phone, wherein the base material and the cover are adjusted so that the thickness, weight, and rigidity are smaller than a case made of the resin having a thickness of 1 mm.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is a laminated housing made of a conventional resin housing formed by resin molding, thereby realizing a lighter, thinner and more rigid housing. is there.

(Principle of the Invention) First, calculation of rigidity will be described with reference to FIG. Generally, the rigidity of an object is given by the product EI of the elastic modulus E and the second moment of area I. The second moment of area I is, for any axis OZ,

[0023]

(Equation 3)

Is given by

Here, η is the distance from the OZ axis to the small area dA. For example, rigidity with respect to an axis passing through the center of a rectangular cross section as shown in FIG.

[0026]

(Equation 4)

## EQU2 ##

The rigidity differs between the case where the laminate is laminated on both sides of the base material and the case where the laminate is laminated only on one side because the position of the shaft is different. Therefore, the above two cases are considered separately.

1) A case in which different materials are laminated on both surfaces of a base material A conventional general housing is formed of only one layer. In this case, a material having a low flexural modulus (base material
0) is used. FIG. 11A is a diagram showing a cross section thereof. In this figure, t _p is the thickness necessary to obtain the rigidity required for the housing of a single material (that according to the application of the housing). Further, the density of the material of the housing [rho _p, the flexural modulus and E _p.

FIG. 11B is a view showing a partial cross section of the laminated casing (when laminated on both sides). FIG. 11B
Are laminated materials (coated bodies in claims) 22, 23,... On both surfaces of a base material 21. As a material of the base material 21, the elastic modulus is lower than that of the laminated materials 22, 23,.
Substantially the same as that of the base 20 is usually selected. The laminated materials 22, 23,... Are formed on both surfaces of the substrate 21 by n layers (n ≧ 1).

Here, the thickness of the substrate 21 is t ₀ , the density is ρ ₀ , the flexural modulus is E ₀ , and the number of layers laminated on the substrate 21 is n
The thickness of the i-th (1 ≦ i ≦ n) layer as (t _i −t
_i-1 ) / 2, the density is ρ _i , the flexural modulus is E _i , the width of the housing section is b, and the depth is d.

In such a case, in order for the laminated housing of FIG. 11B to be lighter, more rigid and thinner than the housing of FIG. There is.

[0033]

(Equation 5)

In the above equation, equation (5A) shows a relational expression relating to stiffness which is a product of bending elastic modulus and second moment of area. Equation (5B) shows the relation between the weight and equation (5C) shows the relation between the thickness. (5A) to (5C)
In the formula, the left side shows the conventional case, and the right side shows the formula for the laminated case of the present invention.

By determining each parameter so as to satisfy the above equations (5A) to (5C), it is possible to obtain a lightweight, thin, and highly rigid housing.

2) Laminating the laminated material only on one side of the substrate Next, the case where the laminated material is laminated on only one side of the substrate will be described. FIG. 12A is a diagram showing a conventional general housing formed of a base 20 made of a material having a low flexural modulus in terms of cost and the like. This housing is shown in FIG.
It is the same as the housing of FIG.

FIG. 12B is a diagram showing a partial cross section of the laminated housing (when laminated on both surfaces). FIG. 12 (b)
In the laminated housing in the above, a laminated material 32,
33 are stacked. As the base material 31, a material having an elastic modulus substantially equal to that of the base material 20 shown in FIG. The laminated materials 32, 33,... Are formed on one side surface of the base material 31 by n layers (n ≧ 1).

Here, when the thickness of the substrate 31 is t ₀ , the density is ρ ₀ , the flexural modulus is E ₀ , and the number of layers laminated on the substrate 31 is n, the i-th (1 ≦ i) ≦ n) The thickness of the layer is (t _i −
t _i-1 ), the density is ρ _i , the flexural modulus is E _i , the width of the housing section is b, and the depth is d.

In such a case, the following expression must be satisfied in order for the laminated housing of FIG. 12B to be lighter, more rigid and thinner than the housing of FIG. 12A. .

[0040]

(Equation 6)

Equation (6A) shows a relational expression relating to stiffness which is a product of bending elastic modulus and second moment of area. Equation (6B) shows the relation between weight and equation (6C) shows the relation between thickness. In formulas (6A) to (6C), the left side shows the conventional case, and the right side shows the formula for the laminated case of the present invention.

In the case of a single-layer housing, when the thickness of the laminated layer increases, the rigidity also changes because the position of the central axis changes. However, in the above equation (6A), the film thickness is sufficiently larger than the substrate thickness. When the center axis is assumed to be located at a position that bisects the cross section of the laminated housing, the rigidity is calculated as follows. Even under such an assumption, the value was very close to the actual rigidity.

By determining each parameter so as to satisfy the above equations (6A) to (6C), it is possible to obtain a lightweight, thin, and highly rigid housing.

As described above, according to the present invention, the laminated housing is formed so as to satisfy the above-mentioned expressions (5A) to (5C) or the expressions (6A) to (6C). As a result, a lightweight, thin, and highly rigid housing can be obtained.

(Embodiment 1) In this embodiment, a laminated housing in which a resin material (ABS resin (acrylonitrile butadiene styrene copolymer)) and a metal material (metal plating layer) are laminated is used for a cellular phone. The following describes an example of a housing used for the above.

FIG. 1 is a view for explaining the configuration of the laminated housing of the present embodiment. FIG. 1A is a cross-sectional view of a conventional resin housing (hereinafter, referred to as comparative housing A), and FIG. 1B is a cross-sectional view of a laminated housing 50 of the present embodiment. As shown in this figure, the laminated housing of the present invention has a base material (ABS resin layer).
1, a metal plating layer 5 (first metal plating layer 2 and second metal plating layer 3) is laminated on both sides.

By the way, the housing for the portable telephone is shown in FIG.
The conventional mobile phone requires a thickness of about 1 mm for the resin housing (that is, the comparative housing A described above) in order to obtain rigidity and impact resistance suitable for its use. It has been.

In the present embodiment, by using the above-described laminated housing 50 as a housing for a portable telephone, the thickness can be reduced (1 mm or less) as compared with the comparative housing A, and at the same time, To achieve weight reduction and high rigidity. Hereinafter, a specific description will be given.

The ABS resin in the base material 1 is the same as the material used for the case (comparative case A) of the conventional mobile phone, and has a flexural modulus of 22000 kgf / cm ² .
The density is 1.19 g / cm ³ and the flammability is
HB equivalent was used. In addition, metal plating layers 2 and 3
Were both composed of copper plating layers.

Here, the two metal plating layers 2,
3 are the same material, and the metal plating layer 5 can be considered to be composed of only one copper plating layer.
Was evaluated as a single copper plating layer. The results of the calculations of the above-described equations (5A) to (5C) are shown below.
The parameters of the equations (5A), (5B) and (5C) are as follows: ρ ₀ = 1.19 g / cm ³ ρ ₁ = 8.93 g / cm ³ ρ _p = 1.19 g / cm ³ E ₀ = 22000 kgf / It was set to _{^{cm 2 E 1 = 800000kgf / cm}} 2 E p = 22000kgf / cm 2 t p = 0.1cm.

FIG. 3 is a diagram showing the result. 3 is a diagram showing the thickness of the base material 1 and the thickness of the metal plating layer 5 necessary to obtain the same rigidity as the comparative case A. That is, a line (equi-rigidity line) in which the rigidity of the laminated housing and the rigidity of the comparative housing A are the same is shown. In this figure, the region above the broken line (equi-rigidity line) is a portion where the rigidity is higher than that of the comparative case A.

The solid line in FIG. 3 is a diagram showing the thickness of the base material 1 and the thickness of the metal plating layer 5 required to have the same weight as the comparative case A. That is, a line (equal weight line) in which the weight of the laminated housing and the weight of the comparative housing A are the same is shown. In this figure, an area below the solid line (equivalent weight line) is a part where the weight is lower than that of the comparative case A.

Therefore, from the above results, it can be seen that the region sandwiched between the broken line and the solid line is a region where the thickness of the ABS resin as the base material 1 can be reduced and the weight and the rigidity can be increased. Therefore, by determining the thickness of the ABS resin 1 and the thickness of the metal plating layer 5 in this region, it is possible to provide a thin, lightweight, thin-walled mobile phone housing with improved rigidity. .

Further, from FIG. 3, the most effective place for the rigidity UP, weight reduction and thinning is the range of the thickness that the metal plating layer 5 can take in the range surrounded by the solid line and the broken line, that is, A in the figure. It can be seen that this is when the length is long. Therefore, the thickness of the substrate 1 is preferably 0.4 mm to 0.6 mm. However, considering the moldability of the resin, the larger the thickness, the better.
Desirably, it is 0.8 mm. The thickness of the metal plating layer 5 for such a substrate 1 can be determined from FIG. For example, when the thickness of the base material 1 is 0.8 mm, the thickness of the metal plating layer 5 may be determined from 3.5 μm to 13.3 μm. In this way, a highly rigid, lightweight, thin-walled mobile phone housing can be realized.

FIG. 4 shows the above-described improvement in rigidity and weight reduction in a more easily understood manner.
The rigidity and weight of the housing 50 of the present embodiment having
This is shown as a comparison value with the conventional mobile phone housing A (1 mm thick) shown in FIG. The horizontal axis indicates the thickness of the metal plating layer 5, and the vertical axis indicates the rigidity increase ratio and the weight reduction ratio as compared with the conventional resin housing A. Here, the thickness of the base material 1 of the housing 50 is 0.8 mm, and the thickness of the metal plating layer 5 is changed from 0 μm to 15 μm.

In FIG. 4, the thickness of the metal plating layer 5 is 1
The area on the right side of 3.3 μm is an area where the weight increases compared to the 1 mm thick mobile phone housing, and the area on the left side of the film thickness of 3.5 μm is an area where the rigidity decreases. From this figure, it is possible to realize a weight reduction of up to about 15% while improving the rigidity, and to realize a rigidity improvement of up to about 120% while reducing the weight. Further, as can be seen by adding the thickness of the metal plating layer 5 on the horizontal axis and the thickness of the base material 1 (0.8 mm), the thickness can be reduced compared to the comparative case A (1 mm thick).

Further, when the effect of the present embodiment is specifically shown, the thickness of the substrate 1 according to the present embodiment is 0.8 mm,
According to the laminated housing 50 in which the thickness of the metal plating layer 5 is 9 μm, the flexural modulus is about 6000 instead of the ABS resin.
1 prepared using a glass reinforced resin of 0 kgf / cm ²
It is possible to obtain the same rigidity as a case having a thickness of mm. That is, in the present embodiment, even if an inexpensive resin is used, thinness and high rigidity can be realized.

As described above, according to the present embodiment, it is possible to increase rigidity, reduce the weight, and reduce the thickness, as compared with the conventional resin housing A.

Next, a method of manufacturing the laminated housing 50 of the present embodiment will be described with reference to FIG. In FIG. 5, 1
Is an ABS resin (base material), 5 is a metal plating layer (2 is a first metal plating layer, 3 is a second metal plating layer), 7 is an electrode,
8 is a mounting jig, 9 is a plating tank, and 6 is a counter electrode.

In the metal plating, as shown in FIG. 5, first, a metal plating layer 2 is formed on the surface of the ABS resin 1 by electroless copper plating. Next, the electrode 7 is brought into contact with the surface of the metal plating layer 2. Then, electrolytic copper plating is performed until a desired film thickness is formed, and a metal plating layer 3 is obtained.

According to the above manufacturing method, the base material 1 is 0.8 mm
Produced a laminated housing 50 having a metal plating layer 5 having a thickness of 9 μm. The thickness of the housing was reduced by 20% compared with a conventional mobile phone housing having a thickness of 1 mm (comparative housing A) and bent. 80% rigidity
Increase and weight could be reduced by 7%.

In the present embodiment, the metal plating layer 5
However, the present invention is not limited to this, and the metal plating layer 5 may be formed of a single layer or may be formed of a plurality of different metals. However, in this case, it is necessary to add each material in the calculation of the conditions such as the film thickness.

In addition, the laminated housing composed of the base material 1 made of resin and the metal plating layer 5 has been described. However, the present invention is not limited to this. Alternatively, two or more kinds of metals having different rigidities may be laminated in place of the resin.

Further, in the present embodiment, the laminated housing for a cellular phone has been described as an example, but the present invention can be used for other various cases. In this case, when the case is formed of a single material, the thickness required from the viewpoint of rigidity and impact strength is _defined as tp, and the above-described formula (5A) to
The laminated housing is formed so as to satisfy (5C) or (6A) to (6C). By doing so, the effects of the present invention can be obtained. t _p is, for example, in the portable information terminal device is about 1.2mm.

It is needless to say that not all parts of the housing need to be constituted by the present laminated housing, and only a part (for example, a part requiring the most rigidity) may be constituted by the present laminated housing. No.

(Embodiment 2) In Embodiment 1, the case where copper plating is applied to both surfaces of a resin molded product has been described, but in this embodiment, copper plating is applied to one surface of a resin molded product. A description will be given of the case in which the application is performed. Here, unlike the first embodiment, 2 in the conventional resin housing.
The case where it is used for an application requiring a film thickness of mm is shown. In the following, the same reference numerals are given to the same parts as in the first embodiment, and the description will be simplified.

FIG. 6 is a sectional view showing Embodiment 2 of the present invention. In FIG. 6, 50 'is a laminated housing, 1 is AB
S resin (substrate), 5 is a metal plating layer (2 is a first metal plating layer, 3 is a second metal plating layer).

In the present embodiment, unlike the first embodiment, conditions such as the film thickness of the metal plating layer 5 are obtained based on the equations (6A) to (6C). The parameters at this time are the same as in the first embodiment, and will not be described.

FIG. 7 is a diagram showing the result of the above calculation.
Here, the horizontal axis represents the thickness t ₀ of the substrate 1 and the vertical axis represents the thickness (t ₁ −t ₀ ) of the metal plating layer 5. The thickness of the metal plating layer 5 is shown by the sum of the first metal plating layer 2 and the second metal plating layer 3 as in the first embodiment.

The broken line in FIG. 7 indicates the thickness of the base material 1 and the thickness of the metal plating layer 5 necessary to obtain the same rigidity as that of a conventional resin housing having a thickness of 2 mm (hereinafter referred to as comparative housing B). FIG. That is, a line (equi-rigidity line) in which the rigidity of the laminated housing and the rigidity of the comparative housing B are the same is shown. In this figure, a region above the broken line (equi-rigidity line) is a portion having higher rigidity than the comparative case B.

The solid line in FIG. 7 is a diagram showing the thickness of the base material 1 and the thickness of the metal plating layer 5 required to have the same weight as the comparative case B. That is, a line (equal weight line) in which the weight of the laminated housing and the weight of the comparative housing B are the same is shown. In this figure, an area below the solid line (equivalent weight line) is a part where the weight is lower than that of the comparative case B.

Therefore, from the above results, it can be seen that the region sandwiched between the broken line and the solid line can be reduced in weight and increased in rigidity while reducing the thickness of the ABS resin as the base material 1. By determining the thickness of the ABS resin 1 and the thickness of the metal plating layer 5 in this region, it is possible to improve the rigidity, thinness and weight.

In FIG. 7, the region where the dashed line and the solid line are farthest from each other is most effective for increasing the rigidity, reducing the weight, and reducing the thickness.
Therefore, it can be said that a substrate thickness of about 1 mm is good. Specifically, if the thickness of the base material 1 is 1 mm and the thickness of the metal plating layer 5 is set between 64 μm and 133 μm, a great effect can be obtained.

FIG. 8 shows the above-described improvement in rigidity and weight reduction in a more easily understood manner.
The rigidity and weight of the housing 50 ′ of the present embodiment having the following are shown as comparison values with the conventional housing (comparative housing B: 2 mm thick). The horizontal axis is the thickness of the metal plating layer 5,
The vertical axis indicates the rigidity increase ratio and the weight reduction ratio as compared with the comparative case B. Here, the thickness of the base material 1 of the housing 50 ′ is 1 mm, and the thickness of the metal plating layer 5 is 50 μm to
It is changed at 150 μm.

In FIG. 8, the thickness of the metal plating layer 5 is 1
The area to the right of 33 μm is an area where the weight increases compared to the 1 mm thick mobile phone housing, and the area to the left of 64 μm is the area where the rigidity decreases. From this figure, it is possible to reduce the weight by up to about 23% while improving the rigidity.
The rigidity can be improved up to about 110% while reducing the weight. Further, as can be seen by adding the thickness of the metal plating layer 5 on the horizontal axis and the thickness (1 mm) of the base material 1, the thickness can be reduced to be larger than that of the comparative case B (2 mm thick). In particular, when the thickness of the metal plating layer 5 is 100 μm (the thickness of the base material 1 is 1 mm), the case thickness is reduced by 45% compared with the comparative case B having a thickness of 2 mm, and the bending rigidity is increased. Can be increased by 50% and the weight can be reduced by 12%.

As described above, according to the present invention, it is possible to realize all of increased rigidity, lighter weight, and thinner thickness as compared with the comparative case B.

Note that the laminated housing of the present embodiment is not limited to the above, and various modifications as described in the first embodiment are possible.

(Embodiment 3) FIG. 9 is a view for explaining a laminated housing of this embodiment. FIG. 9A is a cross-sectional view of a conventional housing using a resin alone (hereinafter referred to as a comparative housing C). A rib 91 is provided on one surface of an ABS resin 90 in order to increase rigidity. FIG. 9B shows a case where the rigidity of the housing shown in FIG.
The height of 2 is increased. By doing so, the rigidity can naturally be increased, but there is a demerit in miniaturization.

In this embodiment, the height of the ribs is increased by coating the upper surface of the ribs with a metal or the like having a large elastic coefficient as shown in FIG. Keep it low. In the example shown in FIG. 9C, since the covering material 95 is provided only on one side of the base material 93, the base material 93 is formed based on the expressions (6A) to (6C) as in the second embodiment. The condition of the covering material 95 may be obtained.

Hereinafter, the laminated housing of the present embodiment will be specifically described. First, as a premise, the comparison case C in FIG. 9A is such that the ABS resin case thickness (h _2a −h _1a ) = 2 mm,
It is assumed that the housing has a housing width b ₁ = 10 mm, a rib height h _1a = 2 mm, and a rib width b ₂ = 4 mm.

Here, if the rigidity is required to be twice as high as that of the comparative case C for a certain application, FIG.
To cope with this by increasing the rib height h _1b as in (b), the total thickness h _2b must be 5.034 mm (the ABS resin housing thickness (h _2b −h _1a ) is constant (2 mm)
And). That is, the rib height h _1b is 3.03.
4 mm is required. In addition, the weight increased by 26%, and the weight increased considerably.

On the other hand, the base material 93 shown in FIG.
If copper and copper plating are used as the resin and the covering material 95 and the laminated housing described in the second embodiment responds to increase in rigidity,
When the ABS resin housing thickness (h _2c −h _1c ) is constant (2 mm), the total thickness h _2c may be 4.037 mm, and the copper plating thickness h _3c may be 37 μm (the rib height h _1c is 2. 037mm
Becomes). The weight is 15% of that of FIG. 9 (b).
Is lighter.

As described above, according to the housing of the present embodiment, the rib height can be reduced by about 1 mm as compared with the case where the housing is made of a conventional single resin, and the size and weight can be reduced. Can make a significant contribution.

In the present embodiment, the coating layer is provided only on one side as in the second embodiment. However, the coating layer may be provided on both sides as in the first embodiment. Further, a coating layer may be provided not only on the rib 94 but also on the base material 93. In order to provide a coating layer only on the rib 94, masking or the like can be easily performed at the time of manufacturing.

According to the laminated housing of the present embodiment described above, light weight, thin wall, and high rigidity can be realized. In addition, the metal plating layer can also function as an electromagnetic wave shielding layer. Can respond to restraint movements. Also, since the flexural modulus of the metal plating layer is higher than that of the resin,
The resin molded product plated with metal can improve the bending elastic modulus. Furthermore, the metal plating layer acts as a flame barrier against fire, so it has better flame resistance than a resin molded product alone, and the material cost can be reduced because a resin with low flame retardancy can be used. Can be.

In addition to the portable telephone, the above-mentioned casing is a casing of a portable video electronic device such as a camera, a video integrated camera, a digital camera, etc., a notebook personal computer, a pocket computer, a calculator, an electronic notebook, Portable information such as PDC, PHS, mobile phone or the case of communication terminal, MD,
The present invention can be applied to various fields such as a case of portable acoustic electronic devices such as a cassette headphone stereo and a radio, and a case of home electric appliances such as a liquid crystal TV / monitor, a telephone, a facsimile, and a hand scanner.

[0087]

According to the present invention, high rigidity can be realized even when a normal resin material is used instead of a reinforcing material filled with glass fiber or carbon fiber having poor fluidity, and the moldability of the housing is improved. Can be improved. In addition, it is possible to realize light weight and thin wall.

Further, when a metal plating layer is used instead of the reinforcing rib, the height of the reinforcing rib of the resin molded product can be suppressed, and the size can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a cross section of a housing according to the first embodiment.

FIG. 2 is a diagram showing a shape of a housing for a mobile phone.

FIG. 3 is a diagram illustrating the weight and rigidity of the housing according to the first embodiment, in which the horizontal axis represents the thickness of the base material and the vertical axis represents the thickness of the metal plating layer.

FIG. 4 is a diagram illustrating the weight and rigidity of the housing according to the first embodiment, where the horizontal axis represents the thickness of a metal plating layer.

FIG. 5 is a diagram illustrating a method for manufacturing the housing of the first embodiment.

FIG. 6 is a diagram illustrating a cross section of the housing according to the second embodiment.

FIG. 7 is a diagram showing the weight and rigidity of the housing of the second embodiment, in which the horizontal axis represents the thickness of the base material and the vertical axis represents the thickness of the metal plating layer.

FIG. 8 is a diagram illustrating the weight and rigidity of the housing according to the second embodiment, where the horizontal axis represents the thickness of a metal plating layer.

FIG. 9 is a diagram illustrating a cross section of the housing of the third embodiment.

FIG. 10 is a diagram illustrating a method of calculating rigidity.

FIG. 11 is a diagram showing a cross section of a housing in which different materials are laminated on both sides.

FIG. 12 is a diagram showing a cross section of a housing in which different materials are laminated on one side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base material 2 1st metal plating layer 3 2nd metal plating layer 5 metal plating layer 50 50 'laminated housing 94 rib 95 covering material

Claims (5)

[Claims] 1. A housing used for an application requiring a thickness of not less than a predetermined thickness when composed of only a first material, comprising: a base material made of the first material; Laminated at least one of a kind different from the first material
And at least one layer of a covering material made of a material of a different material,
A housing characterized in that the weight is small and the rigidity is equal to or more than that. 2. When composed of only the first material, the thickness t
a casing used for an application where _p is required, a base material made of a first material, and n made of at least one kind of material different from the base material laminated on both surfaces of the base material A coating of a layer (n ≧ 1), wherein the substrate has a thickness of t ₀ , a density of ρ ₀ , a flexural modulus of E _0, and an i-th layer (1) of the coating. ≦ i ≦ n), the thickness is (t _i −t _i−1 ) / 2, the density is ρ _i , and the flexural modulus is E _i
, Then A housing characterized by satisfying the above expressions (1A) to (1C). 3. When composed of only the first material, the thickness t
A casing used for an application requiring _p, comprising: a base material made of a first material; and a laminate laminated on only one surface of the base material and made of at least one kind of material different from the base material an n-layer (n ≧ 1) coating, wherein the substrate has a thickness t ₀ , a density ρ ₀ , a flexural modulus E _0, and an i-th layer ( When the thickness of 1 ≦ i ≦ n is (t _i −t _i−1 ), the density is ρ _i , and the flexural modulus is E _i , A housing characterized by satisfying the above formulas (2A) to (2C). 4. The housing according to claim 1, wherein the base member and the cover are formed with ribs. 5. A housing made of a resin having a thickness of 1 mm, comprising: a base made of a resin; and a cover made of at least one metal plating layer formed on one or both surfaces of the base. The case for a mobile phone, wherein the base material and the cover are adjusted so as to be thinner, lighter and more rigid than the mobile phone case.