TWI612880B - Undercarriage and portable machine - Google Patents

Description

Undercarriage and portable machine

The present invention relates to a preferred chassis that is suitable for use in a machine having, for example, a heat-generating electronic component, and a portable machine provided with the chassis.

A conventional portable device or the like protects a display portion for displaying an image from an external impact, and a chassis is used. For example, the display device disclosed in Japanese Laid-Open Patent Publication No. 2006-113589 includes a panel unit and a chassis for fixing and supporting the panel unit and made of SUS.

On the other hand, in recent years, electronic devices such as portable devices have been expected to be lightweight. At this time, since the SUS has a large specific gravity (specific gravity: about 7.8), it is difficult to reduce the weight of the chassis and the display device in the configuration described in Japanese Laid-Open Patent Publication No. 2006-113589. Therefore, in order to reduce the weight of the chassis, it is proposed to use a chassis having a smaller specific gravity than SUS Al (specific gravity: about 2.7). Such a chassis is disclosed, for example, in Japanese Laid-Open Patent Publication No. 2008-177275.

The mobile phone terminal disclosed in Japanese Laid-Open Patent Publication No. 2008-177275 includes an electronic component such as a display, and a casing portion (a chassis) that is formed by accommodating an electronic component and embedding an aluminum component in the resin. In the mobile phone terminal, a graphite-containing heat sink for ensuring heat conduction is adhered between a heat source such as an electronic circuit and a casing portion.

However, the action described in Japanese Patent Laid-Open Publication No. 2008-177275 Although the casing portion of the telephone terminal can reduce the weight of the casing portion, on the other hand, the heat conductivity of Al is insufficient, and the heat of the aluminum component that is conducted from the heat source to the casing portion via the heat sink is not It is sufficiently conducted to the entire aluminum component, and there is a problem that heat cannot be sufficiently radiated in the casing portion.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a chassis that can sufficiently dissipate heat while achieving weight reduction, and a portable device including the chassis.

A chassis according to a first aspect of the present invention is formed of a cladding material in which an Al layer and a Cu layer are bonded; and the Al layer is composed of Al or an Al alloy; the Cu layer is composed of Cu or a Cu alloy, and The thermal conductivity is larger than the Al layer.

According to the first aspect of the present invention, the chassis is formed of a coating material in which an Al layer and a Cu layer having a thermal conductivity higher than that of the Al layer are bonded, and the thermal conductivity is larger than that of the Cu layer of the Al layer. In the case where the chassis is formed only of the Al layer, the thermal conductivity of the chassis can be improved. Thereby, heat can be quickly conducted to the entire chassis, so that heat can be sufficiently radiated in the chassis. Further, by using the Al layer having a small specific gravity, the weight of the chassis can be reduced as compared with the case where the chassis is formed only of the Cu layer. Further, since the chassis is composed of a coating material in which the Al layer and the Cu layer are joined, since the Al layer and the Cu layer are directly bonded to each other, even when the Al plate and the Cu plate are indirectly joined via the adhesive, even Heat conduction can still be performed efficiently at the interface between the Al layer and the Cu layer. Thereby, heat can be quickly conducted to the entire chassis, so that heat can be sufficiently radiated in the chassis.

Further, the term "undercarriage" as used in the present invention refers to a casing, a casing, a frame, an outer frame, and the like that require a certain degree of heat dissipation performance and mechanical strength. For example, a chassis for fixing a display portion for displaying images, for protection on a substrate of a portable device The chassis of the integrated circuit to be mounted, etc., covers a chassis for protecting electronic components of the portable machine. Further, for example, a chassis having a frame function of a portable device, a chassis having a lead function for power supply connection, and a chassis for blocking electromagnetic waves are also included.

According to the chassis of the first aspect described above, it is preferable that the Al layer is composed of an Al alloy having a 0.2% endurance of 200 MPa or more. According to this configuration, since the mechanical strength of the Al layer is increased, the mechanical strength of the chassis can be sufficiently ensured. Therefore, a chassis having high mechanical strength in addition to light weight and high heat dissipation performance can be obtained.

According to the chassis of the first aspect described above, the thickness of the Al layer is preferably 60% or more of the total thickness of the Al layer and the Cu layer. According to this configuration, since the ratio of the Al layer having a small specific gravity can be increased, the weight of the chassis can be further reduced.

According to the chassis of the first aspect described above, it is preferable that the thickness of the Cu layer is larger than 40% of the total thickness of the Al layer and the Cu layer. According to this configuration, since the ratio of the Cu layer having a larger thermal conductivity than that of the Al layer can be increased, the heat dissipation performance of the chassis can be further improved.

According to the chassis of the first aspect described above, it is preferable that the Cu layer is made of Cu. According to this configuration, by forming the Cu layer from Cu having a higher thermal conductivity than the Cu alloy, the heat dissipation performance of the chassis can be further improved.

According to the chassis of the first aspect described above, preferably, the Al layer includes: a first Al layer bonded to the Cu layer on one surface of the Cu layer and composed of Al or an Al alloy, and bonded to the other surface of the Cu layer A Cu layer and a second Al layer made of Al or an Al alloy; and the covering material has a three-layer structure in which the first Al layer, the Cu layer, and the second Al layer are sequentially laminated. According to this, if the covering material having the three-layer structure in which the Cu layer is sandwiched between the first Al layer and the second Al layer from both sides is provided, it is possible to suppress the warpage of the chassis due to the difference in ductility between the Al layer and the Cu layer. Further, since the covering material has a three-layer structure in which a Cu layer is interposed between the first Al layer and the second Al layer, it is possible to suppress the surface of the Cu layer having poor corrosion resistance from being exposed. Department, 俾 can improve the corrosion resistance of the chassis.

In the above-described coating material structure having a three-layer structure of the first Al layer, the Cu layer, and the second Al layer, the average thickness of the second Al layer is preferably 95% or more and 105% or less of the average thickness of the first Al layer. According to this configuration, the chassis can be formed in a slightly symmetrical configuration in the thickness direction. In other words, since the first Al layer and the second Al layer are made of the same (Al-based) metal material and can be formed to have a thickness equal to or less than ±5%, the difference in thickness between the first Al layer and the second Al layer can be suppressed. Caused by warping. Therefore, it is possible to further suppress the warpage of the chassis.

In the above-described coating material structure having a three-layer structure of a first Al layer, a Cu layer, and a second Al layer, it is preferable that the first Al layer and the second Al layer are made of an Al alloy having the same composition. According to this configuration, since the ductility on both sides of the Cu layer can be made almost the same, it is possible to further suppress the warpage of the chassis. In addition, when the average thickness of the second Al layer is 95% or more and 105% or less of the average thickness of the first Al layer, the first Al layer and the second Al layer are made of an Al alloy having the same composition, and It is set to a slightly equal thickness within ±5%, so it is not necessary to distinguish the front and back of the chassis, and the operation in the chassis manufacturing process or the like can be made easier.

In the above-described coating material structure having a three-layer structure of a first Al layer, a Cu layer, and a second Al layer, it is preferable that the thickness of the first Al layer and the thickness of the second Al layer are the first Al layer, the Cu layer, and the second Al layer. The total thickness is 60% or more. According to this configuration, since the ratio of the first Al layer to the second Al layer having a small specific gravity can be increased, the weight of the chassis can be further reduced.

In the above-described coating material structure having a three-layer structure of the first Al layer, the Cu layer, and the second Al layer, the thickness of the Cu layer is preferably larger than 40% of the total thickness of the first Al layer, the Cu layer, and the second Al layer. According to this configuration, since the thermal conductivity can be increased Since the ratio of the Cu layer is larger than that of the first Al layer and the second Al layer, the heat dissipation performance of the chassis can be further improved.

According to the chassis of the first aspect described above, the Al layer is preferably made of an Al-Mg alloy. According to this configuration, by using an Al-Mg alloy containing Mg having a specific gravity smaller than that of Al and having a higher mechanical strength than Al, it is possible to obtain a chassis which is more lightweight and mechanically strong in addition to high heat dissipation. .

Further, the chassis of the present invention can be used as a chassis in which a portable machine that incorporates heat-generating electronic components is built. By using the portable device of the present invention to achieve a lightweight chassis, the lightweight weight of the chassis can be utilized to reduce the weight of the portable device. Moreover, since the heat from the electronic component which is easy to generate heat can be efficiently dissipated through the chassis of the present invention, heat storage in the electronic component can be suppressed, and malfunction of the electronic component due to heat storage can be suppressed. Moreover, when the chassis is in contact with the heat-generating electronic components, the heat from the electronic components can be more efficiently dissipated. In addition, "electronic parts" include not only parts that use electric power such as displays and integrated circuits (ICs), but also parts that supply electric power such as batteries.

According to the chassis of the first aspect described above, it is preferable that at least a part of the surface of the chassis forms a Sn-plated layer composed of Sn or a Sn alloy. According to this configuration, when the chassis in which the Sn-plated layer is not provided is soldered to the support portion or the like, abnormal growth (whisker) of Sn contained in the solder is caused, so at least participation is caused on the surface of the chassis. A Sn-plated layer is formed on a part of the solder to suppress abnormal growth of Sn.

According to the chassis of the first aspect described above, it is preferable that at least a part of the surface of the chassis forms a Ni layer made of Ni or a Ni alloy. According to this configuration, when the chassis is in contact with the electric circuit, by making the electric circuit contact the Ni layer of the chassis, the resistance (contact resistance) at the contact portion between the chassis and the electric circuit can be suppressed. Shape, so the chassis can also be used as a current loop for grounding the electrical circuit. Moreover, since the corrosion resistance of the Ni layer is high, the corrosion resistance of the chassis can be further improved.

According to the chassis of the first aspect described above, the thickness of the chassis formed of the covering material is preferably 0.1 mm or more and 1.0 mm or less. According to this configuration, it is possible to suppress an increase in the size of the machine using the undercarriage due to an excessive thickness while ensuring sufficient mechanical strength required for the chassis.

According to the chassis of the first aspect described above, the preferred covering material has a two-layer structure in which the Al layer and the Cu layer are sequentially laminated. According to this configuration, in the case of the three-layer structure in which the first Al layer, the Cu layer, and the second Al layer are sequentially laminated, the thermal conductivity is higher in the vicinity of the heat-generating electronic component or the like than in the Al layer. The Cu layer can improve the heat dissipation performance of the chassis.

A portable device according to a second aspect of the present invention includes: an electronic component that generates heat; an Al layer made of Al or an Al alloy; and an aluminum layer made of Cu or a Cu alloy and having a thermal conductivity higher than that of the Al layer; The Cu layer is joined to the coated material to form a chassis that releases heat from the electronic parts.

According to the portable device of the second aspect of the present invention, as described above, the chassis having the Al layer and the covering material which is in contact with the Cu layer having a thermal conductivity higher than that of the Al layer has a larger thermal conductivity than Al. The Cu layer of the layer can improve the thermal conductivity of the chassis as compared with the case where the chassis is composed only of the Al layer. Thereby, heat can be quickly conducted to the entire chassis, so that heat can be sufficiently radiated in the chassis. Further, by using an Al layer having a small specific gravity, the weight of the chassis can be reduced as compared with the case where the chassis is formed only of the Cu layer. Further, since the chassis is composed of a coating material in which the Al layer and the Cu layer are joined, the Al layer and the Cu layer are directly bonded to each other. Therefore, in the case of indirect bonding between the Al plate and the Cu plate via the adhesive, The interface between the Al layer and the Cu layer is more efficient Conduct heat conduction. Thereby, heat can be quickly conducted to the entire chassis, so that heat can be sufficiently radiated in the chassis.

According to the portable apparatus of the second aspect described above, it is preferable that the Al layer is composed of an Al alloy having a 0.2% withstand force of 200 MPa or more. According to this configuration, a portable device can be constructed by using a chassis having high mechanical strength and high light weight and high heat dissipation performance.

According to the portable device of the second aspect described above, preferably, the chassis is in contact with an electronic component that is accompanied by heat. According to this configuration, by abutting against the chassis of the electronic component, the heat of the electronic component can be more reliably released.

Preferably, the portable device according to the second aspect of the invention further includes: a substrate on which the electronic component is provided on the upper surface, and a support that is disposed on the upper surface of the substrate and that is in contact with the chassis according to the surrounding electronic component; unit. According to this configuration, even if the portable device in which the electronic component is not in contact with the chassis and the electronic component is separated from the outside by the substrate, the support portion, and the chassis, the chassis having high heat dissipation performance is disposed in the electronic component. In the vicinity of this, it is possible to reduce the weight of the portable device provided with the substrate while efficiently dissipating heat from the easily heat-generating electronic component from the chassis.

1‧‧‧ display

2, 202, 402‧‧‧ chassis

3, 303, 403‧‧‧ substrate

4, 304‧‧‧ battery

21, 221‧‧‧Cu layer

21a‧‧‧Z1 side surface

21b‧‧‧Z2 side surface

22, 23, 222‧‧‧Al layer

31‧‧‧CPU

31a‧‧‧heater

100, 300‧‧‧ portable machines

105‧‧‧roll

121‧‧‧Cu plate

122, 123‧‧‧Al plate

402a, 433a‧‧‧Sn coating

432‧‧‧ solder

433‧‧‧Support

502b‧‧‧Ni layer

Fig. 1 is a perspective view showing the internal structure of a portable device according to an embodiment of the present invention.

Fig. 2 is an exploded perspective view showing the internal structure of a portable device according to an embodiment of the present invention.

Fig. 3 is a cross-sectional view showing the structure of a chassis of a portable device according to an embodiment of the present invention.

4 is an explanatory view showing a manufacturing process of a chassis of a portable machine according to an embodiment of the present invention; intention.

Fig. 5 is a schematic view showing the temperature state of the chassis and the sheet which are performed to confirm the effects of the present invention.

Fig. 6 is a table showing measurement results and the like which are performed to confirm the effects of the present invention.

Fig. 7 is a graph showing the relationship between the Cu ratio, the maximum temperature, and the thermal conductivity of the examples which were carried out to confirm the effects of the present invention.

Fig. 8 is a graph showing the relationship between the Cu ratio and the specific gravity of the examples which were carried out to confirm the effects of the present invention.

Fig. 9 is a cross-sectional view showing the structure of a chassis according to a first modification of the embodiment of the present invention.

Fig. 10 is an exploded perspective view showing the internal structure of a portable device according to a second modification of the embodiment of the present invention.

Figure 11 is a cross-sectional view showing the structure of a chassis according to a third modification of the embodiment of the present invention.

Figure 12 is a cross-sectional view showing the structure of a chassis according to a fourth modification of the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, the internal configuration of the portable device 100 according to an embodiment of the present invention will be described with reference to Figs. 1 to 3 .

As shown in FIGS. 1 and 2, the portable device 100 of the present embodiment has the display 1, the chassis 2, the substrate 3, and the battery 4 arranged in this order from the upper side (Z1 side). Further, the display 1, the chassis 2, and the substrate 3 are formed in a substantially rectangular shape having a length L1 of about 100 mm in the longitudinal direction and a length L2 of about 50 mm in the short-side direction. Further, the battery 4 is formed into a substantially rectangular shape smaller than the substrate 3 in plan view.

The display 1 is composed of a liquid crystal display, an organic EL display, or the like. It has the function of displaying an image on the upper side of the Z1 side. The lower side of the Z2 side of the display 1 abuts (contacts) the upper side of the Z1 side of the chassis 2. That is, the display 1 is disposed in the vicinity of the chassis 2. Further, the display 1 generates heat when displaying an image, and heat generated in the display 1 is mainly released to the outside via the chassis 2. Further, the display 1 is an example of the "electronic component" of the present invention.

The chassis 2 is composed of a substantially rectangular plate material having a thickness t1 of about 0.2 mm in the Z direction. The chassis 2 has a function of protecting the display 1 from an external impact and releasing the heat from the display 1 and the CPU 31 to the outside. The battery 4 has a function of supplying electric power to the display 1, the substrate 3, and the like.

Further, on the Z1 side of the substrate 3, a CPU 31 that executes a program or the like for controlling the portable device 100 is provided. The upper side of the Z1 side of the CPU 31 abuts (contacts) the lower side of the Z2 side of the chassis 2. That is, the CPU 31 is disposed in the vicinity of the chassis 2. In addition, the CPU 31 generates heat by executing a program or the like for controlling the entire portable device 100, and heat generated in the CPU 31 is mainly released to the outside via the chassis 2. Further, the CPU 31 is an example of the "electronic component" of the present invention.

Here, in the present embodiment, as shown in FIG. 3, the chassis 2 is composed of a three-layer structure (Al layer/Cu layer/Al layer) covering material including a Cu layer 21, an Al layer 22, and an Al layer 23; The layer 21 is made of Cu; the Al layer 22 is bonded to the Z1 side surface 21a of the Cu layer 21, and is composed of an Al-Mg alloy; the Al layer 23 is bonded to the Z2 side surface 21b of the Cu layer 21, and is made of Al. -Mg alloy composition. In other words, the chassis 2 is composed of a three-layer structure (Al layer/Cu layer/Al layer) covering material in which the Al layer 22, the Cu layer 21, and the Al layer 23 are sequentially stacked. Further, the Cu layer 21 and the Al layers 22 and 23 are firmly joined to each other by rolling and bonding. Further, the Al layers 22 and 23 are examples of the "first Al layer" and the "second Al layer" of the present invention, respectively. Moreover, the surfaces 21a and 21b are respectively "one of the surfaces" of the present invention. And an example of "another surface."

The Cu layer 21 is formed of Cu having a purity of 99.9% or more such as oxygen-free copper, refined copper, and phosphorus deoxidized copper. Further, the Al layers 22 and 23 are composed of A5052 (JIS standard) or GM55 (manufactured by UACJ Co., Ltd.) in the Al-Mg alloy. Further, the Al layer 22 and the Al layer 23 are composed of an Al-Mg alloy having the same composition.

Further, the Cu system constituting the Cu layer 21 has a thermal conductivity of about 390 W/(m × K) and a specific gravity of about 8.9. On the other hand, in the Al-Mg alloy constituting the Al layers 22 and 23, the A5052 has a thermal conductivity of about 138 W/(m×K) and a specific gravity of about 2.7, and the GM55 has a specific gravity of about 117 W/(m×K). Thermal conductivity, with a specific gravity of about 2.7. That is, the Cu layer 21 has a higher thermal conductivity and a larger specific gravity than the Al layers 22 and 23.

Further, the Cu system constituting the Cu layer 21 has a 0.2% proof stress of about 210 MPa. On the other hand, in the Al-Mg alloy constituting the Al layers 22 and 23, the A5052 has a 0.2% proof stress of about 270 MPa, and the GM55 system has a 0.2% proof force of about 310 MPa. That is, the 0.2% proof of the Al layers 22 and 23 is in a state of about 200 MPa or more. In addition, in order to ensure the mechanical strength in the state in which the chassis 2 is thinned by about 0.2 mm, the 0.2% proof resistance of the three-layer structure covering material is preferably as large as possible.

Further, the Cu layer 21, the Al layer 22, and the Al layer 23 have thicknesses t2, t3, and t4, respectively, in the Z direction. Here, the thickness t3 of the Al layer 22 is slightly equal to the thickness t4 of the Al layer 23. Specifically, the average value of the thickness t4 of the Al layer 23 is in a state of 95% or more and 105% or less of the average value of the thickness t3 of the Al layer 22. Here, the respective interfaces of the Cu layer 21, the Al layer 22, and the Al layer 23 are not formed into a flat surface and are formed into waves. In this case, when the average value of the thickness t4 of the Al layer 23 is 95% or more and 105% or less of the average value of the thickness t3 of the Al layer 22, even in the actual production, even if the thickness t3 of the Al layer 22 is different from the Al layer. The thickness t4 of 23 is regarded as slightly the same There will still be no problems with this.

Furthermore, in the present embodiment, in the weight reduction or high heat dissipation performance of the chassis 2, the high heat dissipation performance of the chassis 2 is emphasized, and the total thickness of the Cu layer 21, the Al layer 22, and the Al layer 23 (the chassis) Below the thickness of 2) t1 (= t2 + t3 + t4), it is preferable that the thickness t2 of the Cu layer 21 is larger than 40%. Further, when the weight of the chassis 2 is emphasized, the thickness t1 of the chassis 2 is preferably 60% or more with respect to the total thickness (= t3 + t4) of the Al layers 22 and 23. That is, the thickness t3 of the Al layer 22 and the thickness t4 of the Al layer 23 are preferably both 30% or more with respect to the thickness t1 of the chassis 2.

Furthermore, when the weight of the chassis 2 is emphasized, the specific gravity of the chassis 2 is preferably about 5 or less.

Further, in the present embodiment, there is no arrangement on the surface of the chassis 2. That is, the surface of the chassis 2 is not disposed as a graphite sheet for heat dissipation. Thereby, when the graphite sheet is continued, the thermal conductivity is lowered due to the intrusion of air bubbles between the sheet and the chassis 2, and the step of continuing the thin graphite sheet can be reduced.

Next, a manufacturing procedure of the underframe 2 according to an embodiment of the present invention will be described with reference to Figs. 1, 3, and 4.

First, as shown in FIG. 4, a Cu plate 121 made of Cu and an Al plate 122 and an Al plate 123 made of any of A5052 or GM55 are prepared. At this time, the thickness of the Al plate 122 is slightly the same as the thickness of the Al plate 123, and the thickness of the Cu plate 121, the thickness of the Al plate 122, and the thickness of the Al plate 123 match the properties of the chassis 2 ( Lightweight and high heat dissipation performance). Specifically, when the chassis 2 emphasizes high heat dissipation performance, the thickness of the Cu plate 121 is made larger than the total thickness of the Cu plate 121 and the Al plates 122 and 123 by 40%. Moreover, when the chassis 2 is focused on weight reduction, the Al plate 122 is The thickness and the thickness of the Al plate member 123 are each 30% or more of the total thickness of the Cu plate 121, the Al plate 122, and the Al plate 123.

In the state in which the Cu plate 121 is disposed between the Al plate 122 and the Al plate 123, the roll 105 is continuously rolled at a rolling reduction ratio of about 60%. Thereby, the covering material 102 having a thickness of about 0.4 mm and sequentially laminated by the Al layer 22, the Cu layer 21, and the Al layer 23 is formed.

Then, the covering material 102 was subjected to diffusion annealing for about 1 minute in a reducing environment of about 500 °C. Then, the covering material 102 is continuously rolled until it becomes about 0.24 mm. Then, in a reducing environment of about 500 ° C, the covering material 102 is again subjected to diffusion annealing for about 1 minute, and then continuous rolling is performed at a predetermined rolling reduction ratio. Thereby, the covering material 102 having a thickness t1 (refer to FIG. 3) of about 0.2 mm is continuously formed. At this time, by bonding the Al layers 22 and 23 which are composed of Al-Mg alloys having the same composition and having the same thickness on the surfaces 21a and 21b of the Cu layer 21, the warpage of the covering material 102 can be suppressed. .

Then, as shown in FIG. 1, the cover member 102 (see FIG. 4) is formed into a substantially rectangular shape having a length L1 of about 100 mm in the longitudinal direction and a length L2 of about 50 mm in the short-side direction, thereby producing a chassis. 2. Further, the chassis 2 is processed into a predetermined shape by press working or the like.

In the present embodiment, the following effects can be obtained.

In the present embodiment, as described above, the chassis 2 is composed of a Cu layer 21 having a thermal conductivity higher than that of the Al layers 22 and 23, an Al layer 22 composed of an Al-Mg alloy, and an Al layer composed of an Al-Mg alloy. It consists of a 23-layer bonded 3-layer structure (Al/Cu/Al) cladding material. Thereby, the thermal conductivity of the chassis 2 can be improved by using the Cu layer 21 having a thermal conductivity higher than that of the Al layers 22 and 23, compared to the case where the chassis 2 is composed only of the Al layer. Thereby, since heat can be quickly conducted to the entire chassis 2, heat can be sufficiently radiated in the chassis 2. Further, by using the Al layers 22 and 23 having a small specific gravity, the chassis 2 can be made lighter than when the chassis 2 is composed only of the Cu layer 21. Further, the chassis 2 is composed of a cladding material in which the Cu layer 21, the Al layer 22, and the Al layer 23 are joined, and since the Al layers 22 and 23 and the Cu layer 21 are directly bonded to each other, compared with the Al plate and In the case where the Cu plate material is indirectly joined via the adhesive, heat conduction can be performed efficiently even at the interface between the Al layers 22 and 23 and the Cu layer 21. Thereby, since heat can be quickly conducted to the entire chassis 2, heat can be sufficiently radiated in the chassis 2.

Further, in the present embodiment, since the Al layers 22 and 23 are composed of an Al-Mg alloy having a 0.2% proof resistance of 200 MPa or more, the mechanical strength of the Al layers 22 and 23 is improved, so that the mechanical strength of the chassis 2 is sufficiently ensured. . Therefore, the chassis 2 having high mechanical strength in addition to light weight and high heat dissipation performance can be obtained.

Further, in the present embodiment, when the weight of the chassis 2 is emphasized, the Al layer 22 and 23 are formed with respect to the total thickness of the Cu layer 21, the Al layer 22, and the Al layer 23 (thickness of the chassis 2) t1. When the total thickness (= t3 + t4) is set to 60% or more, the ratio of the Al layers 22 and 23 having a small specific gravity can be sufficiently increased, so that the weight of the chassis 2 can be further reduced.

Further, in the present embodiment, when the high heat dissipation performance of the chassis 2 is emphasized, the Cu layer 21 is formed by the total thickness (thickness of the chassis 2) t1 of the Cu layer 21, the Al layer 22, and the Al layer 23. When the thickness t2 is set to be larger than 40%, the ratio of the thermal conductivity higher than that of the Cu layers 21 of the Al layers 22 and 23 can be sufficiently increased, so that the heat dissipation performance of the chassis 2 can be further improved.

Furthermore, in the present embodiment, the Cu layer 21 of the chassis 2 is made of Cu. In general, the thermal conductivity of Cu is higher than that of the Cu alloy, and the Cu layer 21 is formed of Cu, so that the heat dissipation performance of the chassis 2 can be further improved.

Further, in the present embodiment, the chassis 2 includes a Cu layer 21 made of Cu, an Al layer 22 made of an Al-Mg alloy bonded to the Z1 side surface 21a of the Cu layer 21, and bonded to the Cu layer 21. The Z2 side surface 21b is composed of a three-layer structure (Al layer/Cu layer/Al layer) of the Al layer 23 composed of an Al-Mg alloy. By the three-layer structure in which the Cu layer 21 is sandwiched between the Al layer 22 and the Al layer 23 by the Al layer 22 and the Al layer 23, the difference in ductility between the Al layers 22 and 23 and the Cu layer 21 can be suppressed. Causes the chassis 2 to warp. In addition, since the covering material has a three-layer structure in which the Cu layer 21 is interposed between the Al layer 22 and the Al layer 23, the surfaces 21a and 21b of the Cu layer 21 having poor corrosion resistance can be prevented from being exposed to the outside, so that the coating can be lifted. The corrosion resistance of the chassis 2.

Further, in the present embodiment, the Al layer 22 and the Al layer 23 formed of the same composition (A5052 or GM55) are slightly the same in thickness (t3 and t4). That is, the average value of the thickness t4 of the Al layer 23 is set to 95% or more and 105% or less of the average value of the thickness t3 of the Al layer 22. Thereby, the chassis 2 can be formed in a slightly symmetrical configuration in the thickness direction (Z direction). That is, since the Al layer 22 and the Al layer 23 are composed of an Al-Mg alloy having the same composition and can be set to a thickness equal to or less within ±5%, it is not necessary to distinguish the front and back surfaces of the chassis 2, and it is possible to The operation in the manufacturing process of the rack 2 and the like is easier. Further, by setting the thicknesses (t3 and t4) to be slightly the same, it is possible to suppress the warpage caused by the difference in the thickness between the Al layer 22 and the Al layer 23, so that the warpage of the chassis 2 can be further suppressed.

Further, in the present embodiment, the Al layers 22 and 23 are composed of an Al-Mg alloy containing A5052 or GM55 having a specific gravity smaller than that of Al and having a higher mechanical strength than Al, thereby achieving high heat dissipation. In addition, the chassis 2 is more lightweight and mechanically strong.

Further, in the present embodiment, as shown in FIG. 1, the heat from the display 1 and the CPU 31 can be efficiently carried out from the chassis 2 by arranging the display 1 and the CPU 31 in the vicinity of the chassis 2 having high heat dissipation performance. Cooling. Further, by bringing the display 1 and the CPU 31 into contact with the chassis 2 having high heat dissipation performance, heat from the display 1 and the CPU 31 can be more efficiently dissipated from the chassis 2 by heat. Thereby, it is possible to suppress the accumulation of heat in the display 1 and the CPU 31, so that it is possible to suppress an erroneous operation of the display 1 and the CPU 31 due to heat.

Further, in the present embodiment, by setting the thickness t1 of the chassis 2 made of the covering material to about 0.2 mm, it is possible to suppress the use of the thickness t1 excessively while ensuring sufficient mechanical strength for the chassis 2. The portable machine 100 of the chassis 2 is in a large size.

Further, in the present embodiment, the portable device 100 is configured such that the Z2 side underside of the display 1 that generates heat is abutted (contacted) on the Z1 side of the chassis 2, and the Z1 side of the CPU 31 that is accompanied by heat is abutted. (Contact) under the Z2 side of the chassis 2. Thereby, the heat of the display 1 and the CPU 31 can be more reliably released by the chassis 2 that is in contact with the display 1 and the CPU 31.

(Example)

Next, the heat dissipation performance measurement and the mechanical strength measurement performed to confirm the effects of the present invention will be described with reference to Figs. 2, 3, and 5 to 8. In addition, "thickness" and "thickness" refer to the average value unless otherwise stated.

In the present embodiment, the chassis 2 of the above embodiment shown in Fig. 3 is used. Specifically, Examples 1 to 4 include a Cu layer 21 made of Cu and Al layers 22 and 23 made of A5052 in an .Al-Mg alloy, and an Al layer 22 and Cu. The layer 21 and the Al layer 23 are sequentially laminated with a covering material. At this time, in the examples 1 to 4, the thickness t1 (= t2 + t3 + t4, total thickness) of the flat coating material (the underframe 2) was set to 0.2 mm, and the thickness t3 of the Al layer 22 was made to be Al. The thickness t4 of the layer 23 is set to be the same. Then, as shown in FIG. 5, the flat-shaped covering material has a substantially rectangular shape having a length L1 of 100 mm in the longitudinal direction (X direction) and a length L2 of 50 mm in the short-side direction (Y direction). The chassis 2 of the embodiments 1 to 4 was obtained.

Here, as shown in FIG. 6, in Examples 1 to 4, the thickness ratio (t3: t2: t4) of the Al layer 22, the Cu layer 21, and the Al layer 23 constituting the chassis 2 is set to 1:2: 1, 1:1: 1, 2:1:2, and 4.5:1:4.5. That is, the ratio (Cu ratio) of the thickness t2 of the Cu layer 21 to the thickness t1 of the chassis 2 is set to 50%, 33%, 20%, and 10%, respectively. Moreover, the ratio (Al ratio) of the total thickness (=t3+t4) of the Al layer 22 and the Al layer 23 with respect to the thickness t1 of the chassis 2 was 50%, 67%, 80%, and 90%, respectively.

Further, in Comparative Example 1, a flat plate material composed of a Cu monomer having a thickness of 0.2 mm was used. Further, in Comparative Example 2, a flat plate material made of A5052 monomer having a thickness of 0.2 mm was used. Further, in the same manner as the chassis 2 of the first to fourth embodiments, the plates of Comparative Examples 1 and 2 have a substantially rectangular shape having a length L1 of 100 mm in the longitudinal direction and a length L2 of 50 mm in the short side direction.

Further, using the specific gravity and thermal conductivity of Comparative Examples 1 and 2 (Cu and A5052), the specific gravity of the chassis 2 of Examples 1 to 4 was determined from the thickness ratios of the Cu layer 21, the Al layer 22, and the Al layer 23, respectively. And thermal conductivity.

(heat dissipation performance)

In the evaluation of the heat dissipation performance, with respect to the chassis 2 of Examples 1 to 4 and the plates of Comparative Examples 1 and 2, the temperature distribution when the heat source was placed on the surface was observed. in particular, As shown in Fig. 5, the heater 31a corresponding to the CPU 31 (see Fig. 2) of the heat source of the present embodiment is adhered to the lower surface of the chassis 2 and the Z2 side of the board. The heater 31a has a length L3 of 10 mm in the X direction and the Y direction.

Then, 1 W of electric power is supplied to the heater 31a to heat the heater 31a. Then, the temperature distribution of the chassis 2 and the sheet material after 5 minutes was observed from the upper side (Z1 side) using an infrared camera apparatus. Then, the temperature at the highest temperature in the chassis 2 and the sheet material was measured, and the measured value was set to the highest temperature.

As a result of the heat dissipation performance shown in Figs. 6 and 7, the chassis 2 of the embodiments 1 to 4 increased in accordance with the Cu ratio (the Al ratio became smaller), and the maximum temperature was lowered. This phenomenon is considered to increase the heat dissipation performance of the chassis 2 by increasing the ratio of the high thermal conductivity Cu (390 W / (m × K)), resulting in a decrease in the maximum temperature.

In particular, Example 1 (50%) having a Cu ratio of more than 40%, the maximum temperature was 43.8 ° C, and it was lower than 44 ° C. Thereby, it was confirmed that the chassis 2 of the first embodiment can efficiently improve the heat dissipation performance. Further, it can be confirmed from the graph shown in Fig. 7 that when the Cu ratio is more than 40%, the high temperature can be made 44.5 ° C or lower, and the heat dissipation performance can be sufficiently improved.

Further, in the chassis 2 of Examples 1 to 4, it was confirmed that the Cu ratio increased (the Al ratio became small), and the thermal conductivity also increased. From this phenomenon, it was confirmed that the heat dissipation performance can be sufficiently improved by increasing the Cu ratio.

(proportion)

As is apparent from the specific gravity shown in Figs. 6 and 8, the chassis 2 of the first to fourth embodiments has a smaller specific gravity as the Cu ratio becomes smaller (the Al ratio becomes larger). In particular, in Examples 2 (33%), 3 (20%), and 4 (10%) having a Cu ratio of 40% or less, it was confirmed that the specific gravity was less than 5. From this, it was confirmed that the chassis 2 of the embodiments 2 to 4 can be effectively reduced in weight. Also, as shown in Figure 8 As shown in the figure, when the Cu ratio is 40% or less (the Al ratio is 60% or more), the specific gravity can be made 5 or less, and it can be confirmed that the weight can be sufficiently reduced.

(Mechanical strength)

Further, in order to evaluate the mechanical strength, the stress-strain diagrams of the chassis 2 of Examples 1 to 4 and the plates of Comparative Examples 1 and 2 were measured to obtain a 0.2% permanent strain (permanent). Stress at strain) (0.2% endurance).

As shown in the results of Fig. 6, it was found that the chassis 2 of Examples 1 to 4 became smaller as the Cu ratio became smaller (the Al ratio became larger), and the 0.2% endurance also became larger. This phenomenon is considered to be caused by the fact that A5052 constituting the Al layers 22 and 23 is larger than 0.2% of the Cu constituting the Cu layer 21. Further, when the chassis 2 is thinned to 0.1 mm or more and 0.3 mm or less, the 0.2% proof force of the chassis 2 is 200 MPa or more, and it is preferable to ensure sufficient mechanical strength as a chassis. From this phenomenon, it is considered that the chassis 2 of the first to fourth embodiments can ensure sufficient mechanical strength even when the thickness is reduced to 0.1 mm or more and 0.3 mm or less.

From the evaluation of the above heat dissipation performance, specific gravity, and mechanical strength, it is known that as the Cu ratio increases, the heat dissipation performance can be improved, and on the other hand, the specific gravity becomes large. Further, by using a Cu layer composed of Cu and a pair of Al layers composed of an Al-Mg alloy (A5052) of 200 MPa or more, the mechanical strength can be made 200 MPa or more. In addition, it is known that when the high heat dissipation performance is emphasized, the heat dissipation performance of the chassis can be sufficiently improved by setting the Cu ratio to more than 40%, and the Al ratio is set to 60% or more when weight reduction is emphasized. , can fully achieve the weight of the chassis. Further, the chassis having a Cu ratio of 40% (Al ratio of 60%) or its vicinity can be sufficiently satisfied by high heat dissipation performance, low specific gravity, and high mechanical strength.

In addition, the embodiments and examples disclosed herein are all illustrative only and should be considered as limiting. The scope of the present invention is not intended to be limited by the description of the embodiments and the embodiments, but the scope of the claims and the scope of the claims and the scope of the claims.

For example, in the above-described embodiment, the chassis 2 is exemplified by a three-layer structural covering material (Al layer/Cu layer/Al layer) which is sequentially laminated by the Al layer 22, the Cu layer 21, and the Al layer 23, but the present invention is not limited to Limited to this. According to the first modification of the above-described embodiment shown in FIG. 9 of the present invention, the chassis 202 may include a Cu layer 221 made of Cu and a Z1 side surface 221a bonded to the Cu layer 221 and made of an Al-Mg alloy. The double layer structure (Al layer/Cu layer) of the Al layer 222 is composed of a cladding material. In this case, it is preferable to arrange the high thermal conductivity Cu layer 221 on one side (for example, the CPU side) where a large amount of heat is generated. Thereby, compared with the case where the covering material has a three-layer structure in which the Al layer 22, the Cu layer 21, and the Al layer 23 are sequentially stacked (the above-described embodiment), it is possible to bring the electronic components (display, CPU, etc.) closer together. The thermal conductivity is configured to be larger than the Cu layer 221 of the Al layer 222, so that the heat dissipation performance of the chassis 202 can be further improved. Moreover, when the high heat dissipation performance of the chassis 202 is emphasized, the thickness t2 of the Cu layer 221 is preferably greater than 40 with respect to the total thickness of the Cu layer 221 and the Al layer 222 (thickness of the chassis 202) t1 (= t2 + t3). %. Further, when the weight of the chassis 202 is emphasized, the thickness t3 of the Al layer 222 is preferably 60% or more with respect to the thickness t1 of the chassis 202. Further, the chassis can also have a coating material of four or more layers. In this case, the covering material is preferably a covering material mainly composed of an Al layer and a Cu layer.

In the above embodiment, the battery 4 is disposed on the lower side of the Z2 side of the substrate 3 as exemplified in FIG. 1, but the present invention is not limited thereto. According to the present invention, as shown in FIG. 10, the portable device 300 according to the second modification of the above-described embodiment may be configured such that the battery 304 is disposed adjacent to the substrate 303 in the short-side direction (Y direction), and the CPU 31 is provided. Abutting the chassis 2 together with the battery 304. Thereby, not only the heat from the display 1, the CPU 31, but also the heat from the battery 304 can be efficiently released from the chassis 2. Further, the battery 304 is an example of the "electronic component" of the present invention.

In the above embodiment, the Z1 side of the CPU 31 is abutted on the Z2 side of the chassis 2, and the present invention is not limited thereto. The invention can also make the CPU not abut against the chassis. For example, in the third modification of the above-described embodiment shown in FIG. 11, the frame-shaped support portion 433 surrounding the CPU 31 is joined by solder 432 on the upper surface (one surface on the Z1 side) of the substrate 403. Then, the bottom frame 402 may be fixed to the support portion 433 by abutting against the upper surface (one surface on the Z2 side) of the lid-shaped chassis 402 formed of the three-layer structure covering material against the upper surface of the support portion 433. Therefore, even if the CPU 31 is not in contact with the chassis 402, and the CPU 31 is separated from the outside by the substrate 403, the support portion 433, and the chassis 402, the mobile terminal (not shown) has a high heat dissipation performance. Since the 402 is disposed in the vicinity of the CPU 31, it is possible to reduce the weight of the mobile terminal provided with the substrate 403 while efficiently dissipating heat from the heat generating CPU 31 from the chassis 402.

In this case, as shown in FIG. 11, it is preferable to form the Sn-plated layer 402a on the surface of the chassis 402. Further, it is preferable to form the Sn-plated layer 433a on the surface of the support portion 433. The attachment of the chassis 402 to the support portion 433 can be performed by mechanical screws or caulking, but the mounting of the minute components is often performed by welding (not shown). When the chassis in which the Sn-plated layer is not provided is soldered to the support portion or the like, there is a case where abnormal growth (whiskers) of Sn contained in the solder occurs. Therefore, it is preferable to form the Sn-plated layer 402a in advance for the portion where the chassis 402 is at least involved in soldering. The Sn-plated layer 402a may be formed on the surface of the covering material before forming the shape of the chassis 402, or may be formed on the surface of the chassis 402 formed in the shape of the chassis 402. In addition, if it is necessary to consider productivity and electroplating formation Preferably, after forming the shape of the chassis 402, the Sn-plated layer 402a is formed on the front and back sides (double-sided sides) of the chassis 402. Further, the Sn-plated layer may be made of Sn or a Sn alloy, and more preferably made of Sn having a purity of 99% or more.

Furthermore, the above embodiment is an example in which the chassis 2 is provided in the portable device 100 including the display 1, but the present invention is not limited thereto. For example, the chassis can be placed on a portable router that does not have a display. In this case, the battery from the router and the heat from the CPU can be efficiently released using the chassis. Alternatively, the chassis can be used in a stationary small machine. Alternatively, the chassis can be used as a housing of an SSD (Solid State Drive).

Further, the above embodiment is an example in which the thickness t1 of the chassis 2 is about 0.2 mm, but the present invention is not limited thereto. In the present invention, the thickness of the chassis may also be less than 0.2 mm or more than 0.2 mm. Further, if the thickness of the chassis is about 0.1 mm or more, it is preferable to ensure sufficient mechanical strength as a chassis. Further, when the thickness of the chassis is about 1.0 mm or less, it is possible to suppress an increase in the size of the machine using the chassis due to an excessive thickness. Further, in the case where the miniaturization is highly emphasized as in a portable type of machine, the thickness of the chassis can be set to be approximately 0.6 mm or more and 1.0 mm or less, without paying attention to the chassis used for the miniaturized SSD. In this case, even if Al (Al000 type) having a low 0.2% proof stress is used as the metal material constituting the Al layer of the present invention, since the thickness of the chassis is large, the mechanical strength can be sufficiently ensured.

In the above embodiment, the electronic component that is likely to generate heat is exemplified by the use of the display 1 and the CPU 31, and the second variation is exemplified by the use of the display 1, the CPU 31, and the battery 304. Not limited to this. In the electronic component which is likely to generate heat in the present invention, electronic components such as a power supply circuit can be used.

Further, the above embodiment is an example in which one chassis 2 composed of three layers of covering materials is used, but the present invention is not limited thereto. In the present invention, the chassis for fixing the display portion for displaying images and the chassis for the integrated circuit to be mounted on the protective substrate, etc., the plurality of members for the chassis formed of the covering material may be used. Form a portable machine.

In the above embodiment, the Al layer 22 (first Al layer) and the Al layer 23 (second Al layer) are both formed of the same Al-Mg alloy, but the invention is not limited thereto. In the present invention, the first Al layer and the second Al layer may be composed of different Al or Al alloys.

In the above embodiment, the example in which the Al layer 22 (first Al layer) and the Al layer 23 (second Al layer) are both composed of A5052 or GM55 is exemplified, but the present invention is not limited thereto. In the present invention, the first Al layer and the second Al layer may be composed of Al or an Al alloy other than A5052 and GM55. For example, when the first Al layer and the second Al layer are composed of an Al-Mg alloy (A5000 system), an Al-Mg-Si alloy (A6000 system) such as A6061, or an Al-Cu alloy (A2000 system) such as A2219, when the sheet material is used. The appropriate treatment (hardening treatment, etc.) can achieve a 0.2% proof force of about 200 MPa or more, and thus it is preferable to ensure mechanical strength as a chassis. Further, when the mechanical strength is not particularly required depending on the use environment or the like, the first Al layer and the second Al layer may be composed of Al (Al000-based) or Al alloy having a 0.2% proof stress of less than about 200 MPa.

In the above embodiment, the Cu layer 21 is exemplified by Cu having a purity of 99.9% or more, but the present invention is not limited thereto. In the present invention, the Cu layer may be formed of a Cu alloy having a Cu purity of about 97% or more, such as C19400 (CDA specification) composed of Cu-2.30Fe-0.10Zn-0.03P. Since the mechanical strength of the Cu alloy is higher than that of the above Cu, the mechanical strength of the chassis can be further improved.

Furthermore, the above embodiment exemplifies an example in which no arrangement is made on the surface of the chassis 2, but the present invention is not limited thereto. In the present invention, a Cu foil layer for heat conduction may be formed on the surface of the chassis, or a sheet such as a heat conductive adhesive sheet for a display and a graphite sheet for heat transfer may be formed on the surface of the chassis. According to the chassis having such a configuration, a thin-plate chassis having high heat dissipation performance can be considered to further enhance market usefulness. Further, the sheet may be formed at least at a position to be in contact with the electronic component of the portable device as long as it is on the surface of the chassis. Further, as shown in the fourth modification of the above embodiment, as shown in Fig. 12, the Ni layer 502b may be formed on the surface (upper and lower surfaces) of the chassis 2. Further, the Ni layer 502b may be formed by plating or may be formed integrally with the chassis 2 as a covering material. Thereby, the increase in the electric resistance (contact resistance) at the portion where the chassis 2 and the electric circuit (not shown) are in contact with each other can be suppressed. Therefore, the chassis 2 can be used as a current circuit for making the electric circuit an earth. Moreover, the corrosion resistance of the chassis 2 can also be improved by the Ni layer 502b. Further, the metal material constituting the Ni layer 502b can be made of a Ni alloy such as Ni or a Ni-P alloy. Further, the Ni layer 502b may be formed at least at a position where it contacts the electronic component of the portable device as long as it is on the surface of the chassis 2, or may be provided only on either of the upper and lower surfaces.

In the above embodiment, the example in which the upper surface of the Z1 side of the CPU 31 abuts on the lower side of the Z2 side of the chassis 2 is exemplified, but the present invention is not limited thereto. In the present invention, the CPU and the chassis may be followed by a thermally conductive adhesive, or the CPU and the chassis may be disposed via other members.

2‧‧‧ Chassis

21‧‧‧Cu layer

21a‧‧‧Z1 side surface

21b‧‧‧Z2 side surface

22, 23‧‧‧Al layer

Claims (20)

A chassis consisting of a cladding material that joins an Al layer and a Cu layer; the Al layer is composed of Al or an Al alloy; the Cu layer is composed of Cu or a Cu alloy, and the thermal conductivity is larger than the Al layer. The Al layer includes: a first Al layer bonded to the Cu layer on one surface of the Cu layer and composed of Al or an Al alloy, and a Cu layer bonded to the Cu layer on the other surface of the Cu layer and composed of Al or A second Al layer composed of an Al alloy. The underframe of claim 1, wherein the Al layer is composed of an Al alloy having a 0.2% endurance of 200 MPa or more. The underframe of claim 1 or 2, wherein the thickness of the Al layer is 60% or more of a total thickness of the Al layer and the Cu layer. The underframe of claim 1 or 2, wherein the thickness of the Cu layer is greater than 40% of the total thickness of the Al layer and the Cu layer. The underframe of claim 1 or 2, wherein the Cu layer is composed of Cu. The underframe according to claim 1 or 2, wherein the covering material has a three-layer structure in which the first Al layer, the Cu layer, and the second Al layer are sequentially laminated. The underframe of the sixth aspect of the invention, wherein the average thickness of the second Al layer is 95% or more and 105% or less of the average thickness of the first Al layer. The underframe of claim 6, wherein the first Al layer and the second Al layer are made of an Al alloy having the same composition. The underframe of the sixth aspect of the invention, wherein the thickness of the first Al layer and the thickness of the second Al layer are 60% or more of a total thickness of the first Al layer, the Cu layer, and the second Al layer. . The underframe of claim 6, wherein the thickness of the Cu layer is greater than 40% of a total thickness of the first Al layer, the Cu layer, and the second Al layer. The underframe of claim 1 or 2, wherein the Al layer is composed of an Al-Mg alloy. For example, the chassis of claim 1 or 2 can be used as a chassis in which a portable machine with built-in heat-generating electronic components is built. A chassis according to claim 1 or 2, wherein at least a part of the surface of the chassis is formed with a Sn-plated layer made of Sn or a Sn alloy. A chassis according to claim 1 or 2, wherein at least a part of the surface of the chassis is formed with a Ni layer made of Ni or a Ni alloy. The underframe according to claim 1 or 2, wherein the thickness of the chassis formed of the covering material is 0.1 mm or more and 1.0 mm or less. The underframe according to claim 1 or 2, wherein the covering material has a two-layer structure in which the Al layer and the Cu layer are sequentially laminated. A portable machine comprising: an electronic component that is accompanied by heat generation; and a chassis that is an Al layer composed of Al or an Al alloy, and Cu composed of Cu or a Cu alloy and having a thermal conductivity greater than that of the Al layer Forming a layer-bonded covering material and releasing heat from the electronic component; the Al layer comprising: a first Al layer bonded to the Cu layer on one surface of the Cu layer and composed of Al or an Al alloy, And a second Al layer bonded to the Cu layer on the other surface of the Cu layer and made of Al or an Al alloy. The portable machine of claim 17, wherein the Al layer of the chassis is made of an Al alloy having a 0.2% endurance of 200 MPa or more. The portable device of claim 17 or 18, wherein the chassis is abutted against the electronic component that is accompanied by heat. The portable device of claim 17 or 18, further comprising: a substrate on which the electronic component is provided; and a support portion disposed on the substrate so as to surround the electronic component The upper surface is abutted against the above-mentioned chassis.