JP5418619B2 - Card type mobile phone - Google Patents

Description

  The present invention provides a first case that forms a front surface of a mobile phone that includes a key switch, a display unit, and the like like a mobile phone that includes a case and a cover, and a rear surface of the mobile phone that is fitted to the first case. In particular, the present invention relates to a thin, light, and small card-type mobile phone.

  In recent years, the demand for mobile phones in the telephone industry has been remarkable, and increasingly thinner, lighter, and smaller sizes are desired. In particular, each manufacturer has introduced state-of-the-art technology for thinning, and the proposal of an ultra-thin housing structure with the reliability required for mobile phones, such as key switch keying resistance and drop impact resistance, is desirable. It is rare.

  In general, in a mobile phone that is carried and used in a bag, pocket, etc., for example, a phone having a key switch, a display unit, etc., as in a conventional mobile phone case described in Patent Document 1. A power supply and various components are mounted on a telephone casing that includes a first casing that forms the front of the telephone and a second casing that fits into the first casing and forms the back of the telephone. Yes. As another conventional example, a printed circuit board in which an electronic component that cannot be reflowed by soldering described in Patent Document 2 is assembled, and an electronic component that can be reflowed by narrowing the surface of the metal printed circuit board with the copper foil forming surface inside. A mobile phone case structure comprising: a case formed by combining the case main body, fixing a transmitter, a receiver, and a grip to a case formed by combining the case main bodies, and incorporating the printed circuit board in the case. In particular, it is presented for the purpose of thinness, light weight, and miniaturization.

  FIG. 1 is an exploded perspective view showing a telephone case structure used in a conventional general mobile phone shown in Patent Document 1. In FIG.

  As shown in this figure, a conventional telephone casing is a box-shaped first casing 601 that forms the front of the telephone, and a box-shaped first casing 601 that fits the first casing 601 and forms the back of the telephone. A printed wiring board 605 on which various electrical components such as a key switch 603 and a display unit 604 are mounted is sandwiched between the first casing 601 and the second casing 602. Are integrated to form a mobile phone. In the conventional mobile phone casing having such a configuration, a resin material is generally used for the first casing 601 and the second casing 602 from the viewpoints of price, ease of processing, and weight reduction.

  FIG. 2 is a cross-sectional view showing a cellular phone housing structure disclosed in Patent Document 2. As shown in FIG.

  As shown in this figure, the printed circuit board 702 in which the electronic component 701 that cannot be solder reflowed is integrated is narrowed down by narrowing the copper foil forming surfaces 704a and 704b including the copper foil pattern on which the electronic component 703 capable of solder reflow is mounted. By sandwiching the metal printed circuit boards formed in step 1 as the first casing 705 and the second casing 706, respectively, the thickness of the cellular phone casing can be reduced and the weight can be reduced.

Japanese Patent No. 2626627 (5th page, FIG. 1) Japanese Patent No. 2629376 (page 3, FIGS. 1 and 2)

  However, the mobile phone casing structure disclosed in Patent Document 1 has several problems.

  The first problem is that when a mobile phone is made thinner, the thickness of the first housing and the second housing is inevitably reduced, so that the wall thickness is reduced and the mechanical strength of the mobile phone is lowered. Invite them. However, since mobile phones are generally assumed to be carried in bags, pockets, etc., it is not preferable to reduce the mechanical strength as the thickness is reduced.

  The second problem is that the wall thickness of each of the first housing and the second housing is sufficient to ensure the mechanical strength of the mobile phone up to a strength that can be stored and carried in a generally assumed bag or pocket. Therefore, it is difficult to achieve the original thinning.

  The third problem is that, in order to secure the mechanical strength of the mobile phone up to the strength that can be stored and carried in a generally assumed bag, pocket, etc., the first housing and the second housing are made of, for example, metal. When such a high-rigidity material is used, generally, when a metal material exceeds the yield point in the material standard, permanent strain remains in the material itself, and the metal material is generally more brittle than a resin material. It is difficult to achieve a reduction in thickness while ensuring mechanical strength.

  As described above, when the mobile phone casing structure disclosed in Patent Document 1 is used, the mechanical strength of the mobile phone is ensured up to a strength that can be stored and carried in a generally assumed bag, pocket or the like, It is difficult to reduce the thickness of the mobile phone with the reliability required for the mobile phone, for example, key switch keying characteristics, drop impact resistance characteristics, etc. It was impossible.

  Since the mobile phone casing structure disclosed in Patent Document 2 is also made thin and small by using a second casing made of a metal material, the general structure is similar to that of Patent Document 1. In particular, when a metal material exceeds the yield point in the material standard, permanent strain remains in the material itself, and metal materials are generally more brittle than resin materials, so that they can be made thin while ensuring mechanical strength. It will be difficult to achieve.

  As described above, when the mobile phone casing structure disclosed in Patent Document 2 is used, the mechanical strength of the mobile phone is ensured up to a strength that can be stored and carried in a generally assumed bag, pocket or the like, It is difficult to reduce the thickness of the mobile phone with the reliability required for the mobile phone, for example, key switch keying characteristics, drop impact resistance characteristics, etc. It was impossible.

  The present invention has been proposed in order to solve such problems of the prior art, and the mechanical strength of a mobile phone is generally up to a strength that can be carried in a bag, pocket, or the like that is generally assumed. It is an object of the present invention to provide a mobile phone that is secure and has the reliability required for a mobile phone, for example, a key switch keying characteristic, a drop impact resistance characteristic, etc. In particular, an object is to provide a thin, light, and small card type mobile phone.

  A card type mobile phone according to the present invention comprises an upper casing made of a metal material and provided with a display unit, a lower casing made of a metal material, and a center frame made of a resin material, the upper casing and the At the position where the upper housing and the lower housing are fitted together, the center frame is disposed on the innermost side, and the upper housing is arranged between the top plate and the top plate. A side plate provided on at least two opposing sides, and the top plate of the upper housing and the center frame are provided in contact with each other.

  According to the present invention, when an external force is applied to an upper and lower casing made of a metal material by enclosing each functional module with a center frame made of a resin material and sandwiching an upper part and a lower part between the upper and lower casing made of a metal material, the external force is applied to the resin material The center frame made of a resin material is deformed before the upper and lower housings made of a metal material are plastically deformed to absorb excessive stress, and the upper housing and the lower housing are directly connected to each other. By connecting them in contact with each other, even if shock waves such as drop impact force are applied to the upper and lower housings, the shock waves are reflected and dispersed at the interface between the upper and lower housings and the center frame, reducing the propagation of shock waves to the center frame and reflecting・ Dispersed shock waves can be received by the upper and lower housings. In addition, by using a material whose main component is a bending elastic modulus in the range of 2 GPa to 17 GPa for the center frame, the excessive stress absorption effect and the shock wave propagation reduction effect can be exhibited most efficiently. Further, by optimizing the LCD module, key switch module, circuit board module, antenna module, and power module so that the thickness of each layer is minimized, the mechanical strength of the mobile phone is generally assumed in addition to the above effects. Thin, lightweight, small card-type mobile phone that has enough strength to be stored in a bag, pocket, etc., and has the reliability required for mobile phones, such as key switch keying resistance and drop impact resistance A telephone can be realized.

It is a disassembled perspective view which shows the telephone housing | casing structure used for the conventional common mobile telephone shown by patent document 1. FIG. It is sectional drawing which shows the mobile telephone housing | casing structure shown by patent document 2. FIG. It is a stress-strain curve of a resin material. It is explanatory drawing of one Embodiment of the card-type mobile phone by this invention. It is a disassembled perspective view which shows the structure of the center frame in the 1st Example of the card-type mobile phone by this invention. It is a disassembled perspective view which shows the clamping structure in the 1st Example of the card-type mobile phone by this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view and a cross-sectional view showing an entire apparatus in a first embodiment of a card type mobile phone according to the present invention. It is a result of a folding resistance load application test and a drop impact resistance test, which are general reliability tests of mobile phones. It is a folding load application test result which is a general reliability test of a mobile phone. It is a drop impact test result which is a general reliability test of a mobile phone. FIG. 4 is an exploded perspective view showing a holding structure in a second embodiment of the card type mobile phone according to the present invention, and a perspective view and a sectional view showing the whole apparatus.

[Construction]
FIG. 3 shows a configuration of an embodiment of a card type mobile phone according to the present invention. Here, FIG. 3A is an overall perspective view of the card type mobile phone according to the present invention, FIG. 3B is a cross-sectional view taken along the line AA of FIG. 3A, and FIG. It is BB sectional drawing.

  A card-type mobile phone 101 according to the present invention includes an upper casing 102 and a lower casing 103 made of a metal material (for example, a metal material such as stainless steel, nickel, titanium, aluminum, and magnesium, and an alloy containing these as a main component), and a resin material. (E.g., PC, PA, PBT, POM, ABS, or a synthetic resin containing these as a main component) A frame structure portion formed of a center frame 106, and a power module 109 for supplying power to the card type mobile phone 101, A circuit board module 108 on which a driver circuit and an LSI (Large Scale Integrated circuit) for functioning the card-type mobile phone 101 are mounted in advance, an antenna module 107 for performing wireless communication, and individual key switches 105a A plurality of key switch modules 105, Is composed of the LCD module 104 is a display function over de type cellular phone 101.

  Here, the LCD module 104, the key switch module 105, the circuit board module 108, the antenna module 107, and the power module 109 are sequentially stacked and mounted in the center frame 106 after optimization so that the stacking thickness is minimized. A center frame 106 in which an LCD module 104, a key switch module 105, a circuit board module 108, an antenna module 107 for performing wireless communication, and a power module 109 are stacked and included is sandwiched between the upper casing 102 and the lower casing 103. The upper housing 102 and the lower housing 103 are connected so as to be in direct contact with each other.

Furthermore, the center frame 106 preferably has a flexural modulus in the range of 2 GPa to 17 GPa. In general, in order to improve the mechanical strength (here, flexural modulus) of resin materials, fillers (for example, glass fiber, carbon fiber, graphite, etc.) are mixed into the main material, or pseudo-2 elements or pseudo-3 elements. The bending elastic modulus can be arbitrarily selected to some extent. However, as shown in FIG. 4, the bending elastic modulus of the center frame 106 is 2 GPa or less. When the above resin material is used, the strain amount ε increases with respect to the applied stress σ, and when an external force is applied to the upper and lower casings 102 and 103 made of a metal material, the deformation amount of the center frame 106 increases. This is because 102 and 103 are plastically deformed. Further, when a resin material having a bending elastic modulus of 17 GPa or more for the center frame 106 is used, the strain amount ε is small with respect to the applied stress σ, but the brittleness is high. This is because when an external force is applied, a failure such as a crack is likely to occur in the center frame 106, and a shock wave such as a drop impact force is also likely to propagate.
[Example 1]
5, 6 and 7 are an exploded perspective view, an overall perspective view and a sectional view showing a first embodiment of the card type mobile phone according to the present invention, and FIG. 8 is a general reliability test of the mobile phone. FIG. 9 is a result of a resistance to folding load application and a drop impact resistance test, FIG. 9 is a result of a resistance to bending load application test that is a general reliability test of a mobile phone, and FIG. 10 is a resistance to resistance that is a general reliability test of a mobile phone. It is a drop impact test result. 5A is an exploded perspective view showing the structure of the center frame in the first embodiment of the card-type mobile phone according to the present invention, and FIG. 5B is the first embodiment of the card-type mobile phone according to the present invention. FIG. 6 is an exploded perspective view showing a holding structure in the first embodiment of the card type mobile phone according to the present invention, and FIG. 7A is a first perspective view of the card type mobile phone according to the present invention. FIG. 7B is a cross-sectional view taken along the line AA in FIG. 7A, and FIG. 7C is a cross-sectional view taken along the line BB in FIG. 7B.

  18 TFT modules (LCD) 104 with TFT-type LCD (Liquid Crystal Display) capable of displaying 65,000 colors with 20,480 (128 × 160) effective pixels, LCD driving circuit and outer frame for mechanical strength reinforcement The rubber key switch 105a is mounted on an FPC (flexible printed circuit board) (not shown) by sandwiching a stainless steel metal dome that transmits an electrical signal to the FPC when the key switch 105a is pushed downward in the figure. A key switch module 105 on which an LED (light emitting diode) for key illumination is mounted on the FPC, an antenna module 107 having an inverted F-type antenna element, a logic circuit LSI 202, and a radio circuit LSI 203 are provided. Surface mounted, not shown speaker, vibrator motor, infrared communication unit, 3 A circuit board module 108 on which a 10,000 pixel CMOS (complementary metal oxide semiconductor) camera module, a flashlight, and an I / O connector are mounted; a power module 109 having a lithium ion battery with a capacity of 300 mAh and a protection circuit (not shown); An SD card connector 201 for an SD memory card is connected to a center frame 106 made of synthetic resin in which 30% glass fiber is mixed in a PC (polycarbonate) having a flexural modulus of 5.889 GPa, an LCD module 104, and a key switch module 105. The antenna module 107, the circuit board module 108, the power module 109, and the SD card connector 201 were sequentially assembled and integrated with the center frame 106 (FIGS. 5A and 5B).

  Next, the LCD module 104, the key switch module 105, the antenna module 107, the circuit board module 108, the power module 109, the SD card connector 201, and a synthetic resin center frame 106 in which 30% glass fiber is mixed in a PC that is sequentially incorporated. Was inserted between the upper frame 102 made of stainless steel from the exposed direction of the key switch 105a of the center frame 106 and the lower case 103 from the opposite direction of the exposed surface of the key switch 105a of the center frame 106 (FIG. 6).

  Here, since the difference t1-t2 between the thickness t1 of the LCD module 104 and the thickness t2 of the key switch module 105 is 0.3 mm, the maximum thickness is 1 on the surface of the circuit board module 108 facing the LCD module 104. A logic circuit LSI 202 with a thickness of .5 mm is selectively surface-mounted with a radio circuit LSI 203 with a maximum thickness of 1.8 mm on the surface facing the key switch module 105 on the circuit board module 108 (FIG. 7A). (B) (c)).

  According to this embodiment, the LCD module 104, the key switch module 105, the antenna module 107, the circuit board module 108, the power module 109, and the SD card connector 201 are sequentially incorporated into a PC having a flexural modulus of 5.889 GPa. By sandwiching the upper and lower parts of the synthetic resin center frame 106 mixed with 30% glass fiber with the upper and lower casings 102 and 103 made of stainless steel, when an external force is applied to the upper and lower casings 102 and 103, the external force propagates to the center frame 106. The center frame 106 is deformed before the upper and lower casings 102 and 103 are plastically deformed, and an excessive stress can be absorbed. Further, the thickness difference between the LCD module 104 and the key switch module 105 is optimized by selectively mounting the logic circuit LSI 202 and the radio circuit LSI 203 on the circuit board module 108 in combination with the above effect. The phone's mechanical strength is secured to the level that it can be carried in a pocket, pocket, etc. that is generally assumed, and has the reliability required for a mobile phone, such as key switch keying resistance, drop impact resistance, etc. A thin, light, and small card type mobile phone 101 can be realized.

  Next, in addition to PC + glass fiber 30% synthetic resin (flexural modulus 5.889 GPa) used in this example, PA [nylon 6] (flexural modulus 1.4 GPa), PBT (flexural modulus 2 GPa), PC + glass fiber 20% mixed synthetic resin (flexural modulus 4.251 GPa), PA + carbon fiber 30% mixed synthetic resin (flexural modulus 17 GPa), PA + carbon fiber 40% mixed synthetic resin (flexural modulus 23.4 GPa) 5 each of the center frames 106 are assembled into the card-type mobile phone 101, and then subjected to a folding resistance load application test (applied load 196N, pass / fail judgment criteria: upper and lower), which is a general reliability test of the mobile phone. Cases 102 and 103 are not plastically deformed) and a drop impact test (drop height 1.5 m, pass / fail judgment criteria: crack in center frame 106, Not occur, such as only it) was carried out. Here, the folding resistance load application test is a test for evaluating whether or not the mechanical strength of the mobile phone is secured to a strength that can be stored and carried in a bag or pocket that is generally assumed. The mobile phone is subjected to a shear load by applying a load (196 N in this case) to the center position between the support pillars evenly on the support pillars that are placed at a relative distance of 100 mm. is there. As a result, when a bending load is applied to the card-type mobile phone 101 as shown in FIG. 8, when the bending elastic modulus of the center frame 106 is less than 2 GPa, the deformation amount of the center frame 106 becomes large, and the upper and lower casings 102 and 103 made of stainless steel are When plastic deformation was applied and a drop impact force was applied to the card-type mobile phone 101, the center frame 106 was cracked or chipped when the bending elastic modulus of the center frame 106 was 23.4 GPa or more. From this test result, in order to ensure the mechanical strength of the card-type mobile phone 101 up to a strength that can be stored in a bag, pocket, etc. that is generally assumed, and to ensure the drop impact resistance, the center frame 106 It has been found that the bending elastic modulus of is in the range of 2 GPa to 17 GPa.

  Further, as a material of the center frame 106, PC, PA [nylon 66], PBT, POM, ABS, or these are mainly used in addition to a synthetic resin mixed with 30% of PC + glass fiber whose bending elastic modulus is in a range of 2 GPa to 17 GPa. A synthetic resin as a component can be used. However, in order to realize a thin, light, and small card-type mobile phone, it is necessary to accurately form a thin and fine shape. Therefore, PC or a synthetic resin mainly composed of PC, PA or PA because of its ease of molding. It is most preferable to use a synthetic resin containing as a main component.

  Next, the optimum structure of the stainless steel upper frame 102, the lower housing 103, and the synthetic resin center frame 106 in which 30% glass fiber is mixed in a PC having a flexural modulus of 5.889 GPa used in this embodiment. The combination of sheet thickness is specified. Four types (0.2 mm, 0.3 mm, 0.45 mm, 0.6 mm) of plate thickness t1 of the upper casing 102, and four types (0.2 mm, 0.3 mm, 0) of plate thickness t2 of the lower casing 103 .45 mm, 0.6 mm), and four types (0.4 mm, 0.6 mm, 0.9 mm, 1.2 mm) of thicknesses t3 of the center frame 106, 5 units each, and each card type mobile phone 101 After installation, a folding resistance load application test (applied load 196 N, pass / fail judgment criteria: upper and lower casings 102 and 103 are not plastically deformed) and drop impact resistance test (drop height), which are general reliability tests of mobile phones 1.5 m, pass / fail judgment criteria: the center frame 106 should not be cracked or chipped). As a result, when a bending load is applied to the card type mobile phone 101 as shown in FIG. 9, when the thickness t3 of the center frame 106 is 0.4 mm, the center regardless of the thicknesses t1 and t2 of the upper and lower casings 102 and 103. When the amount of deformation of the frame 106 is increased, the upper and lower casings 102 and 103 are plastically deformed, and the ratio of the plate thicknesses t1 and t2 of the upper and lower casings 102 and 103 to the plate thickness t3 of the center frame 106 is 1: 2 or less. The deformation amount of the upper and lower casings 102 and 103 was plastically deformed. In addition, when a drop impact force is applied to the card type mobile phone 101 as shown in FIG. 10, when the plate thicknesses t1 and t2 of the upper and lower casings 102 and 103 are 0.2 mm, the center frame 106 does not depend on the plate thickness t3. The frame 106 was cracked or chipped. From the results of this test, the upper and lower casings are used to ensure the mechanical strength of the card-type mobile phone 101 up to the strength that can be stored and carried in bags, pockets, etc. as well as the drop impact resistance. The ratio of the plate thicknesses t1 and t2 of 102 and 103 to the plate thickness t3 of the center frame 106 is 1: 2 or more, and the plate thicknesses t1 and t2 of the upper and lower casings 102 and 103 are 0.3 mm or more. It was found that the plate thickness t3 should be 0.6 mm or more. Here, in order to realize a thin, light, and small card-type mobile phone, the total thickness of the card-type mobile phone 101 is minimized, and the plate thicknesses t1 and t2 of the upper and lower housings 102 and 103 are 0.3 mm, It is obvious that the thickness t3 of the center frame 106 is most preferably 0.6 mm.

  In addition to stainless steel, nickel, titanium, aluminum, magnesium, or an alloy containing these as a main component can be used as the material of the upper and lower casings 102 and 103. Here, as a material of the center frame 106, in addition to the synthetic resin (flexural modulus 5.889 GPa) mixed with PC + glass fiber 30% used in the present embodiment, PA [nylon 6] (flexural modulus 1.4 GPa), PBT ( Bending elastic modulus 2GPa), PC + glass fiber 20% synthetic resin (flexural modulus 4.251GPa), PA + carbon fiber 30% synthetic resin (flexural modulus 17GPa), PA + carbon fiber 40% synthetic resin (flexural modulus) 23.4GPa) is made using nickel, titanium, aluminum and magnesium in addition to stainless steel as the material of the upper and lower casings 102 and 103, and in the same general reliability test for mobile phones as above. A certain folding resistance application test (applied load 196 N, pass / fail judgment criteria: upper and lower casings 102 and 103 are not plastically deformed) and When a drop impact test (drop height of 1.5 m, pass / fail judgment criteria: no cracks, chips, etc. occur in the center frame 106) was performed in each combination, the optimum bending elastic modulus of the center frame 106 (2 GPa to 17 GPa). ) And an optimum combination of thicknesses of the upper casing 102, the lower casing 103, and the center frame 106 (the ratio of the thicknesses t1 and t2 of the upper and lower casings 102 and 103 to the thickness t3 of the center frame 106 is 1: 2). The above results were the same as above.

In summary, in order to realize a thin, light, and small card-type mobile phone, it is necessary that the material of the center frame 106 has a bending elastic modulus in the range of 2 GPa to 17 GPa and can accurately form a thin and fine shape. Therefore, it is most preferable to use PC or a synthetic resin containing PC as a main component, PA or a synthetic resin containing PA as a main component because of its ease of molding. -From the viewpoint of workability and availability, it is most preferable to use stainless steel or an alloy containing stainless steel as a main component, nickel or an alloy containing nickel as a main component, titanium or an alloy containing titanium as a main component. Most preferably, the ratio of the plate thickness t1, t2 to the plate thickness t3 of the center frame 106 is 1: 2 or more.
[Example 2]
FIG. 11 is an exploded perspective view, an overall perspective view, and a cross-sectional view showing a second embodiment of the card type mobile phone according to the present invention. Here, FIG. 11 (a) is an exploded perspective view showing the holding structure in the second embodiment of the card type mobile phone according to the present invention, and FIG. 11 (b) is in the second embodiment of the card type mobile phone according to the present invention. FIG. 11C is a cross-sectional view taken along the line AA of FIG. 11B.

  Here, since the configuration of the center frame 106 in the second embodiment is the same as that of the first embodiment (FIGS. 5A and 5B), the description thereof is omitted. The LCD module 104, the key switch module 105, the antenna module 107, the circuit board module 108, the power module 109, and the SD card connector 201 were sequentially incorporated, and 30% glass fiber was mixed in a PC having a flexural modulus of 5.889 GPa. The center frame 106 made of synthetic resin is sandwiched between the upper frame 102 made of stainless steel from the exposed direction of the key switch 105a of the center frame 106 and the lower frame 103 made of stainless steel from the opposite direction of the exposed surface of the key switch 105a of the center frame 106. did. At this time, the upper casing 102 has arms 501a, 501b, 501c, and 501d having connecting holes, and the center frame 106 has screw holes 502a, 502b, 502d corresponding to the arms 501a, 501b, 501c, and 501d. 503c and 504d, and the lower housing 103 has arms 503a, 503b, 503c, and 503d having connecting holes corresponding to the arms 501a, 501b, 501c, and 501d and screw holes 502a, 502b, 503c, and 504d. After the pinching and fitting, the arms 501a and 503a having the connection holes and the screw holes 502a are connected to the arms 501b and 503b having the connection holes and the screw holes 502b by the connection screws 504a. The connecting screws 504b are used to connect the arms 501c and 503 having connecting holes. And a connecting screw 504c and a screw hole 502c, arm 501d which open connecting hole, a connecting screw 504d and 503d and a screw hole 502d, and each ligated. (FIGS. 11A and 11B). Here, so that the upper casing 102 and the lower casing 103 are directly connected, the relative positional relationship between the upper casing 102, the center frame 106, and the lower casing 103 is such that the upper casing 102 is placed on the outermost surface. The lower housing 103 and finally the center frame 106 are arranged on the innermost side. (FIG. 11C).

  According to this embodiment, the LCD module 104, the key switch module 105, the antenna module 107, the circuit board module 108, the power module 109, and the SD card connector 201 are sequentially incorporated into a PC having a flexural modulus of 5.889 GPa. When an external force is applied to the upper and lower casings 102 and 103 by sandwiching the upper and lower parts of the synthetic resin center frame 106 mixed with 30% glass fiber between the upper and lower casings 102 and 103 made of stainless steel, the external force propagates to the center frame 106. The center frame 106 is deformed before the upper and lower casings 102 and 103 are plastically deformed, and an excessive stress can be absorbed. Further, the relative positions of the upper casing 102 and the lower casing 103 are defined as the upper casing 102, the lower casing 103, and the center frame 106 from the outside of the apparatus so that the upper casing 102 and the lower casing 103 are directly connected to each other, and the upper casing 102 is connected to the upper casing 102 by connecting screws 504a, 504b, 504c, 504d. By connecting the housing 102, the lower housing 103, and the center frame 106 at the same time, even if a shock wave such as a drop impact force is applied to the upper and lower casings 102, 103, the shock wave is an interface between the upper and lower housings 102, 103 and the center frame 106. The impact wave is reflected and dispersed by the center frame 106, and the shock wave propagated to the center frame 106 is received by the upper and lower casings 102 and 103 made of high rigidity stainless steel. Ensuring the strength to the level that can be carried and stored in a bag, pocket, etc. Do reliability, for example, resistance to the key switch keying characteristics, it is possible to realize thin with a drop impact resistance or the like, light weight, a compact card-type portable telephone.

  Also in this embodiment, the material of the center frame 106 is made of PC or a synthetic resin mainly composed of PC, PA or PA, whose bending elastic modulus is in the range of 2 GPa to 17 GPa and can accurately form a thin and fine shape. Synthetic resin is used as the main component, and the upper and lower casings 102 and 103 are made of stainless steel or an alloy containing stainless steel as the main component, nickel or an alloy containing nickel as the main component, because of its mechanical strength, workability, and availability. The first implementation is achieved by using titanium or an alloy containing titanium as a main component and setting the ratio of the plate thicknesses t1 and t2 of the upper and lower casings 102 and 103 to the plate thickness t3 of the center frame 106 to 1: 2 or more. It goes without saying that the same effect as the example can be obtained.

DESCRIPTION OF SYMBOLS 101 Card type mobile phone 102 Upper housing 103 Lower casing 104 LCD module 105a Key switch 105 Key switch module 106 Center frame 107 Antenna module 108 Circuit board module 109 Power module 201 SD card connector 202 Logic circuit LSI
203 LSI for wireless circuit
501a, 501b, 501c, 501d Arm 502a, 502b, 502c, 502d Screw hole 503a, 503b, 503c, 503d Arm 504a, 504b, 504c, 504d Connection screw 601 First housing 602 Second housing 603 Key switch 604 Display unit 605 Printed circuit board 701 Electronic component that cannot be reflowed 702 Printed circuit board 703 Electronic component that can be reflowed 704a, 704b Copper foil forming surface 705 First case 706 Second case

Claims (3)

An upper housing made of a metal material and provided with a display unit;
A lower housing made of a metal material;
A center frame made of a resin material,
The upper housing and the lower housing are fitted,
In the position where the upper housing and the lower housing are fitted, the center frame is disposed on the innermost side,
The upper housing includes a top plate and side plates provided on at least two opposite sides of the top plate,
The top plate of the upper housing and the center frame are provided in contact with each other,
A mobile terminal in which the bending elastic modulus of the center frame is in a range of 2GP to 17GP . The mobile terminal according to claim 1, wherein the upper casing sandwiches the center frame between the side plates. The lower housing includes a bottom plate and side plates provided on at least two opposite sides of the bottom plate,
The mobile terminal according to claim 1, wherein the side plate of the lower housing is provided outside the side plate of the upper housing.

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