JP2015128883A - Chassis and portable device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chassis which enables sufficient heat radiation while achieving weight saving in a portable device incorporating an electronic component.SOLUTION: A chassis 2 comprises a cladding material obtained by joining together Al layers 22 and 23 comprising Al-Mg alloy, and a Cu layer 21 comprising Cu 21 and higher thermal conductivity than the Al layers 22 and 23. Preferably, the Al layers 22 and 23 comprise Al alloy with 0.2% proof stress of 200 MPa or more and the thickness of the Al layers 22 and 23 is 60% or more of the total thickness of the Al layer 22 and 23 and the Cu layer 21.

Description

  The present invention relates to a chassis suitable for, for example, a device incorporating an electronic component that involves heat dissipation, and a portable device including the chassis.

  2. Description of the Related Art Conventionally, in portable devices and the like, a chassis is used to protect a display unit for displaying an image from external impact (see, for example, Patent Document 1).

  Patent Document 1 discloses a display device including a panel unit and a chassis made of SUS for fixing and supporting the panel unit.

  On the other hand, in recent years, weight reduction is desired in electronic devices such as portable devices. At this time, since 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 with the configuration described in Patent Document 1. For this reason, in order to reduce the weight of the chassis, a chassis using Al (specific gravity: about 2.7) having a specific gravity smaller than that of SUS has been proposed (for example, see Patent Document 2).

  Patent Document 2 discloses a mobile phone terminal that includes an electronic component such as a display and a casing (chassis) that is configured to store the electronic component and in which an aluminum component is insert-molded in resin. . In this cellular phone terminal, a heat radiating sheet containing graphite for ensuring heat conduction is attached between a heat source such as an electronic circuit and a casing.

JP 2006-113589 A JP 2008-177275 A

  However, in the casing portion of the mobile phone terminal described in Patent Document 2, the casing portion can be reduced in weight, but due to insufficient thermal conductivity of Al, the heat dissipation sheet is interposed. Therefore, the heat conducted from the heat source to the aluminum part of the housing part is not sufficiently conducted to the entire aluminum part, so that there is a problem that heat cannot be sufficiently radiated in the housing part.

  The present invention has been made to solve the above-described problems, and one object of the present invention is a chassis capable of sufficiently dissipating heat while reducing the weight and a mobile phone including the chassis. Is to provide equipment.

  The chassis according to the first aspect of the present invention includes a clad material in which an Al layer made of Al or an Al alloy and a Cu layer made of Cu or a Cu alloy and having a higher thermal conductivity than the Al layer are joined. Become.

  As described above, the chassis according to the first aspect of the present invention is made of the clad material in which the Al layer and the Cu layer having a higher thermal conductivity than the Al layer are joined, so that the thermal conductivity is higher than that of the Al layer. Due to the large Cu layer, the thermal conductivity of the chassis can be improved as compared with the case where the chassis is composed of only the Al layer. As a result, heat can be quickly transferred to the entire chassis, so that sufficient heat dissipation can be performed in the chassis. Further, by using an Al layer having a small specific gravity, the chassis can be reduced in weight as compared with the case where the chassis is made of only a Cu layer. Furthermore, since the chassis is made of a clad material in which an Al layer and a Cu layer are joined, the Al layer and the Cu layer are directly joined, so that the Al plate material and the Cu plate material are indirectly bonded via an adhesive. Compared with the case where it joins thermally, heat conduction can be performed efficiently also in the interface of Al layer and Cu layer. Also by this, heat can be quickly transmitted to the entire chassis, so that sufficient heat dissipation can be performed in the chassis.

  The “chassis” in the present invention refers to a case, a case, a frame, an outer frame, and the like for applications that require a certain degree of heat dissipation performance and mechanical strength. For example, a chassis for protecting electronic components in a mobile device such as a chassis for fixing a display unit for displaying an image and a chassis for protecting an integrated circuit mounted on a substrate of the mobile device is included. Furthermore, a chassis having a function of a frame (frame) of a portable device, a chassis having a function of leads for electrical connection, a chassis for blocking electromagnetics, and the like are also included.

  In the chassis according to the first aspect, the Al layer is preferably made of an Al alloy having a 0.2% proof stress of 200 MPa or more. If comprised in this way, since the mechanical strength of Al layer becomes large, the mechanical strength of a chassis can fully be ensured. Therefore, in addition to weight reduction and high heat dissipation performance, a chassis with high mechanical strength can be obtained.

  In the chassis according to the first aspect, preferably, the thickness of the Al layer is 60% or more of the total thickness of the Al layer and the Cu layer. If comprised in this way, since the ratio of Al layer with small specific gravity can be enlarged, the weight reduction of a chassis can be achieved more.

  In the chassis according to the first aspect, preferably, the thickness of the Cu layer is larger than 40% of the total thickness of the Al layer and the Cu layer. If comprised in this way, since the ratio of Cu layer whose heat conductivity is larger than Al layer can be enlarged, the thermal radiation performance of a chassis can be improved more.

  In the chassis according to the first aspect, the Cu layer is preferably made of Cu. If comprised in this way, the thermal radiation performance of a chassis can be improved more with Cu layer which consists of Cu whose heat conductivity is higher than Cu alloy.

  In the chassis according to the first aspect, preferably, the Al layer is bonded to the Cu layer on one surface of the Cu layer, and the first Al layer composed of Al or an Al alloy is formed on the Cu layer on the other surface of the Cu layer. The clad material has a three-layer structure in which a first Al layer, a Cu layer, and a second Al layer are laminated in this order. In this way, if the clad material has a three-layer structure in which the Cu layer is sandwiched from both sides by the first Al layer and the second Al layer, the chassis is prevented from warping due to the difference in ductility between the Al layer and the Cu layer. can do. In addition, since the clad material has a three-layer structure in which the Cu layer is sandwiched between the first Al layer and the second Al layer, the surface of the Cu layer having poor corrosion resistance can be prevented from being exposed to the outside, so the corrosion resistance of the chassis. Can be improved.

  In the structure made of the clad material having the three-layer structure of the first Al layer, the Cu layer, and the second Al layer, the average value of the thickness of the second Al layer is preferably 95% or more of the average value of the thickness of the first Al layer. 105% or less. If comprised in this way, a chassis can be made into a substantially symmetrical structure in the thickness direction. That is, since the first Al layer and the second Al layer can be made of the same kind (Al-based) metal material and can have substantially the same thickness within ± 5%, the plate of the first Al layer and the second Al layer can be obtained. Warpage caused by a difference in thickness can be suppressed. Therefore, it can suppress that a chassis warps more.

  In the structure composed of the clad material having the three-layer structure of the first Al layer, the Cu layer, and the second Al layer, preferably, the first Al layer and the second Al layer are composed of an Al alloy having the same composition. . If comprised in this way, since the ductility on both sides of Cu layer can be made substantially the same, it can suppress that a chassis warps more. Furthermore, when the average value of the thickness of the second Al layer is 95% or more and 105% or less of the average value of the 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. In addition, since the thicknesses can be substantially equal to within ± 5%, it is not necessary to distinguish between the front and the back of the chassis, and handling in the manufacturing process of the chassis can be further facilitated.

  In the chassis according to the first aspect, preferably, the Al layer is made of an Al—Mg alloy. With this configuration, by using an Al-Mg alloy containing Mg having a specific gravity lower than that of Al and having a mechanical strength higher than that of Al, in addition to increasing heat dissipation, weight reduction and mechanical strength can be achieved. A more designed chassis can be obtained.

  In addition, the chassis of the present invention can be used as a chassis of a portable device that incorporates an electronic component with heat dissipation. By applying the above-described chassis capable of reducing the weight of the present invention to a portable device that is required to be reduced in weight, the weight of the portable device can be reduced by reducing the weight of the chassis. In addition, since heat from electronic components that tend to generate heat can be efficiently radiated through the chassis of the present invention, heat storage in the electronic components is suppressed, and malfunction of the electronic components due to heat storage can be suppressed. . In addition, when an electronic component with heat dissipation is in contact with the chassis, heat from the electronic component can be radiated more efficiently. The “electronic component” includes not only a component that uses power such as a display or an integrated circuit (IC) but also a component that supplies power such as a battery.

  In the chassis according to the first aspect, an Sn plating layer made of Sn or Sn alloy is preferably formed on at least a part of the surface of the chassis. With this configuration, when a chassis having no Sn plating layer is soldered to a support portion or the like, Sn contained in the solder may grow abnormally (whiskers). By forming the Sn plating layer on at least a part related to soldering, abnormal Sn growth can be suppressed.

  In the chassis according to the first aspect, an Ni layer made of Ni or Ni alloy is preferably formed on at least a part of the surface of the chassis. If comprised in this way, when making an electrical circuit contact a chassis, the electrical resistance (contact resistance) in the contact part of a chassis and an electrical circuit will become large by making an electrical circuit contact the Ni layer of a chassis. Therefore, the chassis can also be used as a current circuit for grounding the electric circuit. Further, since the Ni layer has high corrosion resistance, the corrosion resistance of the chassis can be further improved.

  A portable device according to the second aspect of the present invention includes an electronic component with heat dissipation, an Al layer composed of Al or Al alloy, and a Cu layer composed of Cu or Cu alloy and having a higher thermal conductivity than the Al layer. And a chassis that releases heat from the electronic component.

  As described above, the portable device according to the second aspect of the present invention includes a chassis made of a clad material in which an Al layer and a Cu layer having a thermal conductivity larger than that of the Al layer are joined. Due to the Cu layer having a high thermal conductivity, the thermal conductivity of the chassis can be improved as compared with the case where the chassis is composed of only the Al layer. As a result, heat can be quickly transferred to the entire chassis, so that sufficient heat dissipation can be performed in the chassis. Further, by using an Al layer having a small specific gravity, the chassis can be reduced in weight as compared with the case where the chassis is made of only a Cu layer. Furthermore, since the chassis is made of a clad material in which an Al layer and a Cu layer are joined, the Al layer and the Cu layer are directly joined, so that the Al plate material and the Cu plate material are indirectly bonded via an adhesive. Compared with the case where it joins thermally, heat conduction can be performed efficiently also in the interface of Al layer and Cu layer. Also by this, heat can be quickly transmitted to the entire chassis, so that sufficient heat dissipation can be performed in the chassis.

  According to the present invention, as described above, it is possible to provide a chassis capable of sufficiently radiating heat while reducing weight and a portable device including the chassis.

It is the perspective view which showed the internal structure of the portable apparatus by one Embodiment of this invention. It is the disassembled perspective view which showed the internal structure of the portable apparatus by one Embodiment of this invention. It is sectional drawing which showed the structure of the chassis of the portable apparatus by one Embodiment of this invention. It is a schematic diagram for demonstrating the manufacturing process of the chassis of the portable apparatus by one Embodiment of this invention. It is a schematic diagram for demonstrating observation of the temperature state of the chassis and board | plate material performed in order to confirm the effect of this invention. It is the table | surface which showed the measurement result etc. which were performed in order to confirm the effect of this invention. It is the graph which showed the relationship between the Cu ratio in the Example performed in order to confirm the effect of this invention, the maximum temperature, and thermal conductivity. It is the graph which showed the relationship between Cu ratio and specific gravity in the Example performed in order to confirm the effect of this invention. It is sectional drawing which showed the structure of the chassis by the 1st modification of one Embodiment of this invention. It is the disassembled perspective view which showed the internal structure of the portable apparatus by the 2nd modification of one Embodiment of this invention. It is sectional drawing which showed the structure of the chassis by the 3rd modification of one Embodiment of this invention. It is sectional drawing which showed the structure of the chassis by the 4th modification of one Embodiment of this invention.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

  First, an internal configuration of the mobile device 100 according to an embodiment of the present invention will be described with reference to FIGS.

  In the portable device 100 according to the present embodiment, as shown in FIGS. 1 and 2, the display 1, the chassis 2, the substrate 3, and the battery 4 are arranged in this order from the top (Z1 side). 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 lateral direction when viewed in a plan view. Yes. Further, the battery 4 is formed in a substantially rectangular shape smaller than the substrate 3 when viewed in plan.

  The display 1 includes a liquid crystal display, an organic EL display, and the like, and has a function of displaying an image on the upper surface on the Z1 side. The lower surface of the display 1 on the Z2 side is in contact (contact) with the upper surface of the chassis 2 on the Z1 side. That is, the display 1 is arranged in the vicinity of the chassis 2. The display 1 generates heat when displaying an image, and the heat generated in the display 1 is configured to be released to the outside mainly through the chassis 2. The display 1 is an example of the “electronic component” in the present invention.

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

  A CPU 31 for executing a program for controlling the mobile device 100 is provided on the upper surface of the substrate 3 on the Z1 side. The upper surface of the CPU 31 on the Z1 side is in contact (contact) with the lower surface of the chassis 2 on the Z2 side. That is, the CPU 31 is disposed in the vicinity of the chassis 2. The CPU 31 generates heat when a program for controlling the entire portable device 100 is executed, and heat generated in the CPU 31 is configured to be released to the outside mainly through the chassis 2. Yes. The CPU 31 is an example of the “electronic component” in the present invention.

  Here, in this embodiment, as shown in FIG. 3, the chassis 2 is joined to the Cu layer 21 made of Cu and the surface 21a on the Z1 side of the Cu layer 21 and made of an Al—Mg alloy. Constructed from a clad material having a three-layer structure (Al layer / Cu layer / Al layer) including an Al layer 22 and an Al layer 23 composed of an Al—Mg alloy bonded to the surface 21b on the Z2 side of the Cu layer 21. Has been. That is, the chassis 2 is made of a clad material having a three-layer structure (Al layer / Cu layer / Al layer) in which an Al layer 22, a Cu layer 21, and an Al layer 23 are laminated in this order. The Cu layer 21 and the Al layers 22 and 23 are firmly joined to each other by rolling. The Al layers 22 and 23 are examples of the “first Al layer” and the “second Al layer” in the present invention, respectively. The surfaces 21a and 21b are examples of the “one surface” and the “other surface” in the present invention, respectively.

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

  Further, Cu 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, among the Al—Mg alloys constituting the Al layers 22 and 23, A5052 has a thermal conductivity of about 138 W / (m × K) and a specific gravity of about 2.7. It has a thermal conductivity of 117 W / (m × K) and a specific gravity of about 2.7. That is, the Cu layer 21 has a higher specific gravity than the Al layers 22 and 23, while having a higher specific gravity.

  Further, Cu constituting the Cu layer 21 has a 0.2% proof stress of about 210 MPa. On the other hand, among the Al—Mg alloys constituting the Al layers 22 and 23, A5052 has a 0.2% yield strength of about 270 MPa, and GM55 has a 0.2% yield strength of about 310 MPa. That is, the 0.2% proof stress of the Al layers 22 and 23 is configured to be approximately 200 MPa or more. In order to ensure the mechanical strength while reducing the thickness of the chassis 2 to approximately 0.2 mm, it is preferable that the 0.2% proof stress of the clad material having a three-layer structure is large.

  The Cu layer 21, the Al layer 22, and the Al layer 23 have thicknesses t2, t3, and t4 in the Z direction, respectively. Here, the thickness t3 of the Al layer 22 and the thickness t4 of the Al layer 23 are substantially equal. Specifically, the average value of the thickness t4 of the Al layer 23 is configured to be 95% or more and 105% or less of the average value of the thickness t3 of the Al layer 22. Here, the interface of each of the Cu layer 21, the Al layer 22, and the Al layer 23 is not flat and may be formed to wave. In such a case, when the average value of the thickness t4 of the Al layer 23 is not less than 95% and not more than 105% of the average value of the thickness t3 of the Al layer 22, in the actual production, There is no problem even if the thickness t3 and the thickness t4 of the Al layer 23 are regarded as being substantially equal.

  Moreover, in this embodiment, when weighting the high heat dissipation performance of the chassis 2 out of the weight reduction or high heat dissipation performance of the chassis 2, the total thickness of the Cu layer 21, Al layer 22, and Al layer 23 (chassis 2 The thickness t2 of the Cu layer 21 with respect to t1 (= t2 + t3 + t4) is preferably larger than 40%. Further, when importance is attached to the weight reduction of the chassis 2, the total thickness (= t3 + t4) of the Al layers 22 and 23 with respect to the thickness t1 of the chassis 2 is preferably 60% or more. That is, the thickness t3 of the Al layer 22 and the thickness t4 of the Al layer 23 are preferably 30% or more with respect to the thickness t1 of the chassis 2.

  Further, when importance is attached to the weight reduction of the chassis 2, the specific gravity of the chassis 2 is preferably about 5 or less.

  In the present embodiment, nothing is arranged on the surface of the chassis 2. That is, no graphite sheet for heat dissipation is disposed on the surface of the chassis 2. Thereby, when adhering the graphite sheet, it is possible to suppress a decrease in thermal conductivity due to air bubbles entering between the sheet and the chassis 2 and to adhere a thin graphite sheet. It is possible to reduce the number of processes.

  Next, a manufacturing process of the chassis 2 according to one embodiment of the present invention will be described with reference to FIGS.

  First, as shown in FIG. 4, a Cu plate material 121 made of Cu, and an Al plate material 122 and an Al plate material 123 made of any one of Al5052 and GM55 are prepared. At this time, the thickness of the Al plate 122 and the thickness of the Al plate 123 are made substantially equal, and the thickness of the Cu plate 121, the thickness of the Al plate 122, and the thickness of the Al plate 123 are determined according to the properties (weight reduction) And adjust according to the high heat dissipation performance). Specifically, when high heat dissipation performance is emphasized in the chassis 2, the thickness of the Cu plate 121 is set to be larger than 40% of the total thickness of the Cu plate 121 and the Al plates 122 and 123. When weight reduction is important in the chassis 2, the thickness of the Al plate 122 and the thickness of the Al plate 123 are set to 30% or more of the total thickness of the Cu plate 121, the Al plate 122, and the Al plate 123, respectively. .

  Then, in a state where the Cu plate 121 is disposed between the Al plate 122 and the Al plate 123, rolling joining is continuously performed using the roller 105 at a rolling reduction of about 60%. Thereby, the clad material 102 having a thickness of about 0.4 mm and having the Al layer 22, the Cu layer 21, and the Al layer 23 laminated in this order is continuously formed.

  Thereafter, the cladding material 102 is diffusion-annealed in a reducing atmosphere at about 500 ° C. for about 1 minute. And it rolls continuously until the clad material 102 becomes about 0.24 mm. Then, after the cladding material 102 is diffusion-annealed again for about 1 minute in a reducing atmosphere at about 500 ° C., rolling is continuously performed at a predetermined reduction rate. Thereby, the clad material 102 having a thickness t1 (see FIG. 3) of approximately 0.2 mm is continuously formed. At this time, the clad material 102 is warped by joining Al layers 22 and 23 made of Al-Mg alloy having the same composition and having substantially the same thickness on the surfaces 21a and 21b of the Cu layer 21, respectively. Is suppressed.

  Thereafter, as shown in FIG. 1, by punching the clad material 102 (see FIG. 4) 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 lateral direction. The chassis 2 is manufactured. The chassis 2 is processed into a predetermined shape by pressing or the like.

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

  In the present embodiment, as described above, the chassis 2 is made of the Cu layer 21 having a higher thermal conductivity than the Al layers 22 and 23, the Al layer 22 composed of an Al—Mg alloy, and the Al—Mg alloy. It is composed of a clad material having a three-layer structure (Al / Cu / Al) joined to the composed Al layer 23. Thereby, the thermal conductivity of the chassis 2 can be improved by the Cu layer 21 having a thermal conductivity higher than that of the Al layers 22 and 23 as compared with the case where the chassis 2 is composed only of the Al layer. Accordingly, heat can be quickly transmitted to the entire chassis 2, so that sufficient heat radiation can be performed in the chassis 2. Further, by using the Al layers 22 and 23 having a small specific gravity, the chassis 2 can be reduced in weight as compared with the case where the chassis 2 is composed only of the Cu layer 21. Furthermore, since the chassis 2 is made of a clad material in which the Cu layer 21, the Al layer 22, and the Al layer 23 are joined, the Al layers 22 and 23 and the Cu layer 21 are joined directly, so that the Al plate material Compared with the case where the Cu plate material and the Cu plate material are indirectly bonded via an adhesive, heat conduction can be efficiently performed also at the interface between the Al layers 22 and 23 and the Cu layer 21. Also by this, heat can be quickly transmitted to the entire chassis 2, so that sufficient heat radiation can be performed in the chassis 2.

  In this embodiment, since the Al layers 22 and 23 are made of an Al—Mg alloy having a 0.2% proof stress of 200 MPa or more, the mechanical strength of the Al layers 22 and 23 is increased. Sufficient strength can be ensured. Therefore, in addition to weight reduction and high heat dissipation performance, the chassis 2 having high mechanical strength can be obtained.

  In this embodiment, when weight reduction of the chassis 2 is important, the total thickness of the Al layers 22 and 23 with respect to the total thickness (the thickness of the chassis 2) t1 of the Cu layer 21, the Al layer 22, and the Al layer 23. By setting the thickness (= t3 + t4) to 60% or more, the ratio of the Al layers 22 and 23 having a small specific gravity can be sufficiently increased, and thus the weight of the chassis 2 can be further reduced.

  In this embodiment, when the high heat dissipation performance of the chassis 2 is emphasized, the thickness t2 of the Cu layer 21 with respect to the total thickness (thickness of the chassis 2) t1 of the Cu layer 21, Al layer 22, and Al layer 23 is set to By making it larger than 40%, the ratio of the Cu layer 21 having a thermal conductivity higher than that of the Al layers 22 and 23 can be sufficiently increased, so that the heat dissipation performance of the chassis 2 can be further enhanced.

  In the present embodiment, the Cu layer 21 of the chassis 2 is made of Cu, so that the Cu layer 21 made of Cu generally has a higher thermal conductivity than that of the Cu alloy, so that the heat dissipation performance of the chassis 2 is further enhanced. be able to.

  Moreover, in this embodiment, the chassis 2 is joined to the Cu layer 21 made of Cu, the surface 21 a on the Z1 side of the Cu layer 21, the Al layer 22 made of an Al—Mg alloy, and the Cu layer 21. A clad material having a three-layer structure (Al layer / Cu layer / Al layer) including an Al layer 23 composed of an Al—Mg alloy is bonded to the surface 21b on the Z2 side. As a result, the clad material has a three-layer structure in which the Cu layer 21 is sandwiched from both sides by the Al layer 22 and the Al layer 23, thereby causing the chassis 2 due to the difference in ductility between the Al layers 22 and 23 and the Cu layer 21. Can be prevented from warping. In addition, since the clad material has a three-layer structure in which the Cu layer 21 is sandwiched from both sides by the Al layer 22 and the Al layer 23, the surfaces 21a and 21b of the Cu layer 21 having poor corrosion resistance are prevented from being exposed to the outside. Therefore, the corrosion resistance of the chassis 2 can be improved.

  In the present embodiment, the thicknesses (t3 and t4) of the Al layer 22 and the Al layer 23 formed with the same composition (A5052 or GM55) are substantially equal. 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 made into a substantially symmetrical structure in the thickness direction (Z direction). That is, since the Al layer 22 and the Al layer 23 are made of an Al—Mg alloy having the same composition and can have substantially the same thickness within ± 5%, it is necessary to distinguish the front and back of the chassis 2. And the handling of the chassis 2 during the manufacturing process can be further facilitated. Further, by making the thicknesses (t3 and t4) substantially the same, it is possible to suppress the warpage caused by the difference in thickness between the Al layer 22 and the Al layer 23, thereby further suppressing the chassis 2 from warping. can do.

  In the present embodiment, the Al layers 22 and 23 are made of A5052 or GM55 Al—Mg alloy containing Mg having a specific gravity lower than that of Al and having a mechanical strength higher than that of Al, thereby achieving high heat dissipation. In addition to the reduction, it is possible to obtain the chassis 2 that is further reduced in weight and mechanical strength.

  Further, in the present embodiment, as shown in FIG. 1, the heat from the display 1 and the CPU 31 is effectively radiated 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. It can be performed. Furthermore, heat from the display 1 or CPU 31 can be radiated more effectively from the chassis 2 by bringing the display 1 or CPU 31 into contact with the chassis 2 having high heat dissipation performance. Thereby, since it can suppress that heat is accumulate | stored in the display 1 or CPU31, it can suppress that the display 1 or CPU31 malfunctions resulting from a heat | fever.

(Example)
Next, with reference to FIG. 2, FIG. 3, FIG. 5 to FIG. 8, the measurement of the heat dissipation performance and the measurement of the mechanical strength performed to confirm the effect of the present invention will be described. Unless otherwise specified, “thickness” and “plate thickness” are intended to be average values.

  In this example, the chassis 2 of the above embodiment shown in FIG. 3 was used. Specifically, as Examples 1 to 4, a Cu layer 21 made of Cu and Al layers 22 and 23 made of A5052 out of an Al—Mg alloy were provided. Then, a clad material in which the Al layer 23 was laminated in this order was prepared. At this time, in Examples 1 to 4, the thickness t1 (= t2 + t3 + t4, total plate thickness) of the flat clad material (chassis 2) is set to 0.2 mm, and the thickness t3 of the Al layer 22 and the thickness of the Al layer 23 are set. t4 was made the same. Then, as shown in FIG. 5, the flat clad 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 lateral direction (Y direction). The chassis 2 of Examples 1-4 was produced by shape | molding.

  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 of the thickness t2 of the Cu layer 21 to the thickness t1 of the chassis 2 (Cu ratio) was 50%, 33%, 20%, and 10%, respectively. Further, the ratio (Al ratio) of the total thickness (= t3 + t4) of the Al layer 22 and the Al layer 23 to the thickness t1 of the chassis 2 was set to 50%, 67%, 80%, and 90%, respectively.

  In addition, as Comparative Example 1, a flat plate material composed of a simple substance of Cu having a thickness of 0.2 mm was used. Further, as Comparative Example 2, a flat plate material composed of a single A5052 having a thickness of 0.2 mm was used. The plate materials of Comparative Examples 1 and 2 were also formed into a substantially rectangular shape having a length L1 of 100 mm in the longitudinal direction and a length L2 of 50 mm in the lateral direction, similarly to the chassis 2 of Examples 1 to 4.

  Further, using the specific gravity and thermal conductivity in Comparative Examples 1 and 2 (Cu and A5052), the specific gravity of the chassis 2 of Examples 1 to 4 is determined from the ratio of the thicknesses of the Cu layer 21, Al layer 22 and Al layer 23. And thermal conductivity were determined respectively.

(Heat dissipation performance)
In the evaluation of the heat dissipation performance, the temperature distribution was observed when the heat source was arranged on the surface of the chassis 2 of Examples 1 to 4 and the plate materials of Comparative Examples 1 and 2. Specifically, as shown in FIG. 5, a heater 31 a corresponding to the CPU 31 (see FIG. 2) that is a heat generation source of the present embodiment is pasted on the lower surface of the chassis 2 and the plate material on the Z2 side. The heater 31a has a length L3 of 10 mm in the X direction and the Y direction.

  The heater 31a was heated by supplying 1 W of power to the heater 31a. And the temperature distribution of the chassis 2 and board | plate material after 5 minutes was observed from upper direction (Z1 side) using the infrared thermography apparatus. And the temperature of the location where temperature became the highest among the chassis 2 and a board | plate material was measured, and the measured value was made into the highest temperature.

  As a result of the heat dissipation performance shown in FIG. 6 and FIG. 7, in the chassis 2 of Examples 1 to 4, the maximum temperature was lowered as the Cu ratio was increased (Al ratio was decreased). It is considered that this is because the maximum temperature was lowered as a result of the increase in the heat dissipation performance of the chassis 2 due to the increase in the ratio of Cu (390 W / (m × K)) having a high thermal conductivity.

  In particular, in Example 1 (50%) in which the Cu ratio was larger than 40%, the maximum temperature was 43.8 ° C., which was lower than 44 ° C. Thereby, it has confirmed that the chassis 2 of Example 1 can improve heat dissipation performance effectively. Moreover, from the graph shown in FIG. 7, when the Cu ratio was larger than 40%, it was confirmed that the maximum temperature could be 44.5 ° C. or less, and the heat dissipation performance could be sufficiently improved. .

  Further, in the chassis 2 of Examples 1 to 4, the thermal conductivity increased as the Cu ratio increased (the Al ratio decreased). From this, it was confirmed that the heat dissipation performance can be sufficiently enhanced by increasing the Cu ratio.

(specific gravity)
From the specific gravity shown in FIGS. 6 and 8, in the chassis 2 of Examples 1 to 4, the specific gravity decreased as the Cu ratio decreased (the Al ratio increased). In particular, it was confirmed that the specific gravity was smaller than 5 in Examples 2 (33%), 3 (20%), and 4 (10%) in which the Cu ratio was 40% or less. Thereby, it has confirmed that the chassis 2 of Examples 2-4 can achieve weight reduction effectively. From the graph shown in FIG. 8, when the Cu ratio is 40% or less (Al ratio is 60% or more), the specific gravity can be 5 or less, and the weight can be sufficiently reduced. It could be confirmed.

(Mechanical strength)
Further, for the evaluation of the mechanical strength, when the stress strain diagram is measured for the chassis 2 of Examples 1 to 4 and the plate materials of Comparative Examples 1 and 2, a permanent strain of 0.2% occurs. Stress (0.2% yield strength) was determined.

  As a result shown in FIG. 6, in the chassis 2 of Examples 1 to 4, the 0.2% proof stress increased as the Cu ratio decreased (the Al ratio increased). This is probably because A5052 constituting the Al layers 22 and 23 has a 0.2% proof stress greater than that of the Cu constituting the Cu layer 21. In addition, when thinning the chassis 2 to 0.1 mm or more and 0.3 mm or less, the 0.2% proof stress of the chassis 2 is preferably 200 MPa or more in order to secure sufficient mechanical strength as the chassis. . From this, even if the chassis 2 of Examples 1-4 is thinned to 0.1 mm or more and 0.3 mm or less, it is thought that sufficient mechanical strength is ensured.

  From the evaluation of the heat dissipation performance, specific gravity and mechanical strength, it has been found that the heat dissipation performance improves while the specific gravity increases as the Cu ratio increases. It has also been found that the mechanical strength can be increased to 200 MPa or more 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. Among them, when high heat dissipation performance is important, the heat dissipation performance of the chassis can be sufficiently increased by increasing the Cu ratio to more than 40%, and when weight reduction is important, the Al ratio should be increased. It has been found that the weight of the chassis can be sufficiently reduced by setting it to 60% or more. Furthermore, it is considered that a chassis having a Cu ratio of 40% (Al ratio of 60%) or a ratio in the vicinity thereof can sufficiently satisfy all of high heat dissipation performance, low specific gravity, and high mechanical strength. It is done.

  The embodiments and examples disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments and examples but by the scope of claims for patent, and includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, an example is shown in which the chassis 2 is configured by a clad material (Al layer / Cu layer / Al layer) having a three-layer structure in which an Al layer 22, a Cu layer 21, and an Al layer 23 are laminated in this order. However, the present invention is not limited to this. In the present invention, as in the first modification of the embodiment shown in FIG. 9, the chassis 202 is joined to the Cu layer 221 made of Cu and the surface 221a on the Z1 side of the Cu layer 221, and Al—Mg You may comprise from the clad material of the 2 layer structure (Al layer / Cu layer) containing Al layer 222 comprised with an alloy. In this case, it is preferable to arrange the Cu layer 221 having a high thermal conductivity on the side where much heat is generated (for example, the CPU side). Further, when importance is attached to the high heat dissipation performance of the chassis 202, the thickness t2 of the Cu layer 221 with respect to the total thickness (the thickness of the chassis 202) t1 (= t2 + t3) of the Cu layer 221 and the Al layer 222 is more than 40%. Larger is preferable. Further, when importance is attached to the weight reduction of the chassis 202, the thickness t3 of the Al layer 222 with respect to the thickness t1 of the chassis 202 is preferably 60% or more. The chassis may be a clad material having a four-layer structure or more. At this time, the clad material is preferably a clad material mainly composed of an Al layer and a Cu layer.

  Moreover, in the said embodiment, although the example which arrange | positions the battery 4 to the lower surface side by the side of Z2 of the board | substrate 3 was shown in FIG. 1, this invention is not limited to this. In the present invention, the battery 304 is arranged so as to be adjacent to the substrate 303 in the short direction (Y direction) as in the mobile device 300 of the second modification of the embodiment shown in FIG. Both may be configured to abut against the chassis 2. Thereby, not only the heat from the display 1 and the CPU 31 but also the heat from the battery 304 can be efficiently released from the chassis 2. The battery 304 is an example of the “electronic component” in the present invention.

  In the above embodiment, the example in which the upper surface on the Z1 side of the CPU 31 is brought into contact with the lower surface on the Z2 side of the chassis 2 is shown in FIG. 1, but the present invention is not limited to this. In the present invention, the CPU does not have to contact the chassis. For example, as in the third modification of the above-described embodiment shown in FIG. 11, a frame-shaped support portion 433 that surrounds the CPU 31 is joined to the upper surface (the surface on the Z1 side) of the substrate 403 using the solder 432. The chassis 402 may be fixed to the support portion 433 so that the lower surface (Z2 side surface) of the lid-shaped chassis 402 made of the clad material having a three-layer structure is in contact with the upper surface of the support portion 433. Thereby, since the chassis 402 having high heat dissipation performance is disposed in the vicinity of the CPU 31, a portable terminal (not shown) provided with the substrate 403 while effectively radiating heat from the CPU 31 that easily generates heat from the chassis 402. It is possible to reduce the weight.

  In this case, it is preferable to form an Sn plating layer 402a on the surface of the chassis 402 as shown in FIG. In addition, it is preferable to form the Sn plating layer 433 a on the surface of the support portion 433. Although the chassis 402 can be attached to the support portion 433 mechanically by screws or caulking, it is often performed by soldering (not shown) in attaching a micro component. When a chassis having no Sn plating layer is soldered to a support portion or the like, Sn contained in the solder may grow abnormally (whiskers). Therefore, it is preferable to form the Sn plating layer 402a on at least a portion of the chassis 402 that is involved in soldering. The Sn plating layer 402 a may be formed on the surface of the clad material before forming the chassis 402, or may be formed on the surface of the chassis 402 after forming the chassis 402. In consideration of productivity, jigs and tools required for plating formation, it is preferable to form the Sn plating layer 402a on substantially the entire front and back surfaces (both surfaces) of the chassis 402 after the chassis 402 is formed. In addition, as Sn plating, what consists of Sn or a Sn alloy is applicable, and what consists of Sn with a purity of 99% or more is more preferable.

  Moreover, although the example which provided the chassis 2 in the portable apparatus 100 provided with the display 1 was shown in the said embodiment, this invention is not limited to this. For example, the chassis may be provided in a portable router that does not have a display. In this case, it is possible to efficiently release the heat from the battery of the router and the CPU through the chassis. Further, the chassis may be used for a stationary small device. Further, the chassis may be used as a housing for an SSD (Solid State Drive).

  In the above embodiment, an example in which the thickness t1 of the chassis 2 is approximately 0.2 mm has been described, but the present invention is not limited to this. In the present invention, the thickness of the chassis may be smaller than 0.2 mm or larger than 0.2 mm. The chassis thickness is preferably about 0.1 mm or more because sufficient mechanical strength as the chassis can be secured. Moreover, it is preferable that the thickness of the chassis is approximately 1.0 mm or less because it is possible to suppress an increase in the size of a device in which the chassis is used due to the thickness being too large. In addition, in a chassis used for an SSD in which downsizing is relatively less important than in the case where downsizing is very important as in portable devices, the thickness of the chassis is set to approximately 0.6 mm to 1.0 mm. Good. In this case, even if Al (A1000 series) having a relatively small 0.2% proof stress is used as the metal material constituting the Al layer of the present invention, the mechanical strength is sufficiently ensured because the thickness of the chassis is large. Is possible.

  Moreover, in the said embodiment, although the example which uses the display 1 and CPU31 as an electronic component which is easy to generate | occur | produce was shown, the example which uses the display 1, CPU31, and the battery 304 as an electronic component which is easy to generate | occur | produce was shown in the said 2nd modification. The present invention is not limited to this. In the present invention, for example, an electronic component such as a power supply circuit may be used as the electronic component that easily generates heat.

  Moreover, in the said embodiment, although the example using one chassis 2 comprised from the clad material of 3 layers was shown, this invention is not limited to this. In the present invention, a plurality of chassis members made of a clad material are used for a chassis for fixing a display unit for displaying an image, a chassis for protecting an integrated circuit mounted on a substrate, and the like. It can also be configured.

  Moreover, although the Al layer 22 (first Al layer) and the Al layer 23 (second Al layer) are both configured by the same Al—Mg alloy in the above embodiment, the present invention is not limited to this. Absent. In the present invention, the first Al layer and the second Al layer may be composed of different Al or Al alloys.

  Moreover, although the Al layer 22 (first Al layer) and the Al layer 23 (second Al layer) are both configured by A5052 or GM55 in the above embodiment, the present invention is not limited to this. In the present invention, the first Al layer and the second Al layer may be made of Al or Al alloy other than A5052 and GM55. For example, the first Al layer and the second Al layer are made of an Al—Mg alloy (A5000 series), an Al—Mg—Si alloy (A6000 series) such as A6061, and an Al—Cu alloy (A2000 series) such as A2219. However, the 0.2% proof stress can be increased to about 200 MPa or more by an appropriate process (hardening process or the like) at the time of producing the plate material, which is preferable for ensuring the mechanical strength as the chassis. Further, when mechanical strength is not so required due to the use environment or the like, the first Al layer and the second Al layer may be made of Al (A1000 series) or Al alloy whose 0.2% proof stress is less than about 200 MPa. Good.

  Moreover, in the said embodiment, although the Cu layer 21 showed the example formed with Cu of purity 99.9% or more, this invention is not limited to this. In the present invention, the Cu layer may be formed of a Cu alloy having a purity of Cu of approximately 97% or more, such as C19400 (CDA standard) made of Cu-2.30Fe-0.10Zn-0.03P. Since these Cu alloys have higher mechanical strength than Cu, the mechanical strength of the chassis can be further improved.

  Moreover, although the example which does not arrange | position anything on the surface of the chassis 2 was shown in the said embodiment, this invention is not limited to this. In the present invention, a Cu foil layer for heat conduction may be formed on the surface of the chassis, a heat conductive adhesive sheet for bonding a display on the surface of the chassis, a graphite sheet for electric heating, etc. The sheet may be arranged. If it is a chassis which has such a structure, it is thought that the usefulness in a market further increases as a thin chassis which has high heat dissipation performance. Moreover, the said sheet | seat should just be formed in the position which contacts the electronic component of a portable apparatus among the surfaces of a chassis. Further, a Ni layer 502b may be formed on the surface (upper and lower surfaces) of the chassis 2 as in the fourth modification of the embodiment shown in FIG. The Ni layer 502b may be formed by plating, or may be formed integrally with the chassis 2 as a clad material. As a result, it is possible to suppress an increase in the electrical resistance (contact resistance) at the contact portion between the chassis 2 and an electrical circuit (not shown), and therefore the current for grounding the chassis 2 to the electrical circuit (earth). It can also be used as a circuit. Further, the corrosion resistance of the chassis 2 can be improved by the Ni layer 502b. As the metal material constituting the Ni layer 502b, a material made of Ni or a Ni alloy such as a Ni-P alloy can be applied. Further, the Ni layer 502b only needs to be formed on the surface of the chassis 2 at least at a position in contact with the electronic component of the portable device, and may be provided on only one of the upper and lower surfaces.

  In the above-described embodiment, the example in which the upper surface on the Z1 side of the CPU 31 is in contact with the lower surface on the Z2 side of the chassis 2 has been described, but the present invention is not limited to this. In the present invention, the CPU and the chassis may be bonded via a heat conductive adhesive, or the CPU and the chassis may be arranged via other members.

1 Display (electronic parts)
2, 202, 402 Chassis 21, 211 Cu layer 21a Surface (one surface)
21b Surface (the other surface)
22 Al layer (first Al layer)
23 Al layer (second Al layer)
31 CPU (electronic parts)
100, 300 Portable device 222 Al layer 304 Battery (electronic component)
402a Sn plating layer 502b Ni layer

Claims (13)

  A chassis comprising a clad material in which an Al layer made of Al or an Al alloy and a Cu layer made of Cu or a Cu alloy and having a higher thermal conductivity than the Al layer are joined.   The chassis according to claim 1, wherein the Al layer is made of an Al alloy having a 0.2% proof stress of 200 MPa or more.   The chassis according to claim 1 or 2, wherein a thickness of the Al layer is 60% or more of a total thickness of the Al layer and the Cu layer.   The chassis according to claim 1 or 2, wherein a thickness of the Cu layer is larger than 40% of a total thickness of the Al layer and the Cu layer.   The chassis according to claim 1, wherein the Cu layer is made of Cu. The Al layer is bonded to the Cu layer on one surface of the Cu layer, and is bonded to the Cu layer on the other surface of the Cu layer. A second Al layer composed of
The chassis according to claim 1, wherein the clad material has a three-layer structure in which the first Al layer, the Cu layer, and the second Al layer are laminated in this order.   The chassis according to claim 6, wherein an average value of the thickness of the second Al layer is 95% or more and 105% or less of an average value of the thickness of the first Al layer.   The chassis according to claim 6 or 7, wherein the first Al layer and the second Al layer are made of an Al alloy having the same composition.   The chassis according to claim 1, wherein the Al layer is made of an Al—Mg alloy.   The chassis of any one of Claims 1-9 used as a chassis of the portable apparatus which incorporates the electronic component with heat dissipation.   The chassis according to any one of claims 1 to 10, wherein an Sn plating layer made of Sn or an Sn alloy is formed on at least a part of the surface of the chassis.   The chassis according to claim 1, wherein a Ni layer made of Ni or Ni alloy is formed on at least a part of the surface of the chassis. Electronic components with heat dissipation,
It consists of a clad material in which an Al layer made of Al or an Al alloy and a Cu layer made of Cu or a Cu alloy and having a higher thermal conductivity than the Al layer are joined, and releases heat from the electronic component A portable device comprising a chassis to be operated.

Images