JP2015056440A - Electronic apparatus having display screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus having a display screen capable of sufficiently releasing the heat from components while reducing the thickness.SOLUTION: The electronic apparatus having a display screen of the present invention includes: a base board mounted with components each of which emits heat; a shield frame provided to the base board; a screen display protection plate; and an engagement part which is formed on at least one of the screen display protection plate and the shield frame to engage both. In the electronic apparatus having a display screen, the screen display protection plate and the shield frame are thermally engaged with each other, and the screen display protection plate is used as a shield top plate to cover the shield frame.

Description

  The present invention relates to an electronic device having a display screen, and more particularly to an electronic device that can sufficiently dissipate heat from components constituting the electronic device.

  An electronic device having a screen display similar to the device size (hereinafter, represented by the description of the mobile terminal) such as a mobile terminal such as a mobile phone, a smartphone, or a tablet terminal, or a personal computer or a thin TV has a large screen display.

  For this reason, problems such as display device damage, driver cracks (display device drive IC damage), display device display abnormalities, white spots, etc. may occur, and a screen display protection frame is provided to prevent such problems. Yes. Furthermore, in order to reduce the thickness of the apparatus, a thin metal plate having a high strength is used as the protective frame.

  In recent mobile terminals, with the increase in functionality and speed between signals, noise is avoided by surrounding the functional block consisting of parts or multiple parts mounted on the board with a shield so that it is not affected by electromagnetic waves. It needs to be reduced. Therefore, a large shield frame is used.

  In addition, portable terminals have a problem of heat generation due to increase in heat generation due to increase in power consumption due to multi-function, high functionality and high speed, restriction of heat release due to waterproof function, and the like.

  In order to solve the problem of apparatus heat generation in a portable terminal in which the apparatus size cannot be increased, it is required how heat can be diffused throughout the apparatus. The most important heat source of the device is a component mounted on the substrate, and it is necessary to efficiently transfer heat from the substrate to the entire device such as a housing. A protective sheet metal for display is used as an effective component for transferring heat to the entire apparatus.

  In order to transfer the heat of the shield frame to the display protection sheet metal, there is a mounting method in which the sheet metal and the shield shield top plate are brought into contact with each other to transmit heat to the shield frame, but there is a component height between the display protection sheet metal and the shield frame. In addition, there is a clearance, that is, an air layer, for absorbing tolerance deviations such as solder floating and shield frame height tolerance. The air layer has a low thermal conductivity of 0.0241 [W / m · k], so that heat is not sufficiently transferred to the protective sheet metal for display.

  In order to improve thermal conductivity, an object was sandwiched between the sheet metal of the housing and the shield frame. However, the thickness was not constant due to the above-described tolerance shift, and therefore, a cushioning material had to be sandwiched. The heat conductivity of the cushioning parts is about 10 [W / m · k], and the heat conductivity is not as high as that of the metal with the maximum heat conductivity of 428 [W / m · k], and sufficient heat dissipation. I can't.

Further, in the liquid crystal display device of Patent Document 1 (Japanese Patent Laid-Open No. 2008-197164), in order to prevent a high frequency from the timing controller board 72 from leaking and becoming an electromagnetic interference wave to peripheral devices, it is made of a grounded metal. Covering with a shield member 81 is described. Specifically, the support base 13 is formed on the bottom surface 11 of the metal rear frame 1, a female screw hole is provided in the support base 13, and the timing controller board 72 is fastened and fixed to the female screw hole with a bolt. (Paragraphs 0041 and 0042, FIG. 3)
Further, in the sheet metal chassis of Patent Document 2 (Japanese Patent Application Laid-Open No. 2000-323857), a cut and raised claw 8 is provided in the flat sheet metal 2, and when the sheet metal 2 is cut and bent, the cut of the shape of the raised claw 8 is flat. No. 2 is described, and the parts fixed to the cut and raised claws 8 are described. By changing the chassis material from resin to sheet metal, the chassis itself has a shielding effect, and the entire chassis can dissipate heat, eliminating the shield plate and heat dissipation plate, and reducing the number of parts. (0019 paragraph, 0028 paragraph, FIGS. 2, 3 and 4)
Further, in Patent Document 3 (Japanese Patent Laid-Open No. 2001-256619), a heat diffusion sheet 8 is provided that adheres to almost the entire area of the chassis 2 that supports the screen display panel 21 on the back side, and the heat diffusion sheet 8 is attached to the chassis 2. An extension portion 8-a is provided outside the outer shape of the extension portion. The extension portion 8-a is extended to the heat radiating portion 9 on the back side of the extension portion, and heat is released to the outside.

JP 2008-197164 A JP 2000-323857 A JP 2001-256619 A

  In Patent Document 1, the timing controller board 72 is merely fastened to the four female screw holes with bolts, and no effort is made to easily dissipate heat to the rear frame 1 side. Further, the shield member 81 only covers the timing controller board 72 so as not to leak high frequency, and does not sufficiently contribute to heat radiation to the rear frame 1 side.

  In Patent Document 2, parts such as the front panel 9 and the front substrate 5 are fixed by the cut and raised claws 8. However, the cut and raised claws 8 are in contact with the front panel 9 and the front substrate, which are considered to be insulators, at the end portions. For this reason, heat dissipation of components mounted on the front substrate 5 or the like is not taken into consideration.

  Moreover, since the thermal diffusion sheet is added in Patent Document 3, the thickness of the apparatus increases and it is difficult to reduce the thickness.

  An object of the present invention is to solve the above-described problems and provide an electronic device that can sufficiently radiate components and can be thinned.

  The present invention is an electronic device provided with a display screen, wherein a substrate on which a component that releases heat is mounted, a shield frame provided on the substrate, a screen display protection sheet metal, the screen display protection sheet metal, and the shield frame An engaging portion that engages both of the screen display protection sheet metal and the shield frame to thermally connect the screen display protection sheet metal to the shield frame. It is an electronic device provided with a display screen, characterized in that it is also used as a shield top plate for covering.

  According to another aspect of the present invention, there is provided an electronic apparatus including a display screen, a substrate on which a component that releases heat is mounted, at least one engaging portion provided on the substrate, and a shield that is engaged with the engaging portion and shielded. A screen display protection sheet metal having an engagement plate to be a frame, and the screen display protection sheet metal and the substrate are engaged with the engagement portion and the engagement plate to thermally connect the screen display protection sheet metal to the engagement portion; An electronic device provided with a display screen, wherein the screen display protection sheet metal is used as a shield top plate covering the shield frame.

  According to the present invention, it is possible to sufficiently dissipate components of an electronic device having a display screen and to reduce the thickness.

It is a figure which shows the board | substrate of the portable terminal of the 1st Embodiment of this invention, (a) is sectional drawing, (b) is a top view. It is the top view which showed the shape before the press work of the sheet metal 2 used in FIG. It is the figure which showed the shape after the press work of the sheet metal 2 used in FIG. 1, (a) is sectional drawing, (b) is a top view. It is a figure which shows the housing | casing 1 which integrally molded the sheet metal 2 and resin, (a) is sectional drawing, (b) is a top view. 4A and 4B are diagrams showing a shield frame 4 mounted on a substrate 3, where FIG. 5A is a cross-sectional view, and FIG. It is sectional drawing which compares the case where the sheet metal 2 and the shield top plate 40 are provided separately (a), and the case where both are combined (b). It is a figure which shows the board | substrate used by the 2nd Embodiment of this invention, (a) is sectional drawing, (b) is a top view. It is a figure which shows the housing | casing 1 which integrally molded the sheet metal 2 and resin used in the 2nd Embodiment of this invention, (a) is sectional drawing, (b) is a top view. It is a top view which shows the sheet metal 2 used by the 3rd Embodiment of this invention.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, for a mobile terminal incorporating a circuit board 3 (hereinafter abbreviated as a board), heat released from a component such as a semiconductor mounted on the board is radiated to a screen display protection sheet metal (hereinafter abbreviated as a sheet metal). Is.

  1A and 1B are diagrams showing the relationship between the sheet metal 2 of the housing 1 and the shield frame 5 of the substrate 3 after the substrate 3 is incorporated in the housing 1, wherein FIG. 1A is a cross-sectional view, and FIG. It is. For easy understanding, in FIG. 1 (b), the substrate 3 is seen through and the shield frame 4 underneath is drawn. In FIG. 1A, there is a display device 100 having a display screen such as a liquid crystal or an organic EL (Electro-Luminescence) on the opposite side of the substrate 3 with the sheet metal 2 interposed therebetween.

  The sheet metal 2 originally protects the display device 100 from the damage described in the background art. 2 and 3 are views showing the shape of the sheet metal 2 before and after the press working, respectively.

  The sheet metal 2 is a flat sheet metal before pressing. The metal plate 2 is provided with a necessary number (7 in the case of FIGS. 2 and 3) of hooks 5 for bringing the metal plate 2 into contact with and fitting to the shield frame 4 of the substrate 3. A slit 53 is formed around the hook 5 so that the hook 5 is perpendicular to the sheet metal 2 after press working.

  The hook 5 has an engagement hole 51 in the center so as to engage with the projection of the shield frame 4. The material of the sheet metal 2 is preferably a metal having high thermal conductivity, but may be a practical material in terms of thermal conductivity, strength, and cost. For example, it may be selected from stainless steel, aluminum alloy, titanium alloy, copper alloy and the like.

  After the press working, the hook 5 is perpendicular to the sheet metal 2 as shown in the cross section shown in FIG. FIG. 3B is a plan view.

  4A and 4B are diagrams showing a casing 1 in which a sheet metal 2 is integrally formed with a resin. FIG. 4A is a sectional view and FIG. 4B is a plan view. A resin is integrally formed on the outer frame of the sheet metal 2. The housing 1 is provided with a required number (three in this embodiment) of positioning hooks 6 for positioning and fixing the substrate 3.

  5A and 5B are diagrams showing the shield frame 4 mounted on the substrate 3, in which FIG. 5A is a cross-sectional view and FIG. 5B is a plan view.

  The shield frame 4 is a metal that electromagnetically shields the circuit component 8 from being affected by electromagnetic waves generated by surrounding circuit components. The shield frame 4 has no shield top plate, and the circuit components 8 in the shield frame 4 are exposed. In the example of FIG. 5, the periphery is surrounded by the shield frame 4 in units of function or operating frequency.

  Further, the shield frame 4 is fitted to the hook 5 formed on the sheet metal 2. The hook 5 and the protrusion 7 are brought into contact with each other with a sufficient area so that the heat from the circuit component can be sufficiently released to the screen display protection sheet metal. Therefore, a necessary number of hemispherical projections 7 are provided. In this embodiment, the number is the same as the hook 5.

  In order to perform sufficient heat dissipation, there are methods such as increasing the number of protrusions 7 and hooks 5 and increasing the dimensions. The number and dimensions of the protrusions 7 and the hooks 5 are determined in consideration of the heat dissipation amount of the circuit component 8 and the heat dissipation performance of the shield frame 4 and the screen display protection sheet metal 2. The material of the shield frame 4 is preferably a metal having high thermal conductivity, but may be a practical material in terms of thermal conductivity, strength, and cost. For example, it may be selected from stainless steel, aluminum alloy, titanium alloy, copper alloy and the like.

  As shown in FIG. 2, a flat sheet metal 2 is provided with a hook 5 that fits and contacts the shield frame 4 of the substrate 3. The engagement hole 51 at the center of the hook 5 is engaged with the hemispherical projection of the shield frame 4, but the size of the hole is slightly larger than the projection. This is to absorb the positional deviation of the casing 1 and the substrate 3 in the thickness direction, the component height of the shield frame 4, and the tolerance of solder floating.

  When the hook 5 is pressed so as to be perpendicular to the sheet metal 2, the shape shown in FIG. 3 is obtained.

  When the sheet metal 2 and the resin, which is an existing technique, are integrally formed on the sheet metal 2 after the press working in FIG. 3, the resin bites around the sheet metal 2 as shown in FIG. The housing 1 has a role of protecting the screen display. The housing 1 is provided with three positioning hooks 6 and has a role of positioning the substrate 3.

  Further, when the metal plate 2 and the shield frame 4 are fitted, the positioning hook 6 is hidden by the substrate 3 so that the metal plate 2 and the shield frame 4 can be fitted even when the fitting portion is not visible. It also has a role of positioning the sheet metal 2 and the shield frame 4 for the purpose.

  As shown in FIG. 5, the substrate 3 is equipped with a shield frame 4 to block electromagnetic waves to the components, but the shield frame 4 does not have a top surface (shield top plate), and circuit components 8 in the shield frame 4. Is exposed. The shield frame 4 is covered with a shield top plate to block electromagnetic waves. Further, the shield frame 4 is provided with the projection 7 so as to match the position of the hook 5 of the sheet metal 2, and the projection 7 has a role of fitting and contacting the hook 5 of the sheet metal 2 with each other.

  When the substrate 3 of FIG. 5 is incorporated into the housing 1 of FIG. 4 with the positioning hooks 6 as a guide, the result is as shown in FIG. The substrate 3 is held in the housing 1 by the positioning hook 6, and the hook 5 and the projection 7, which are positioned by the positioning hook 6, are fitted and contacted at the same time when the substrate 3 is assembled, and the sheet metal 2 and the shield frame 4 are made of metal. Connected with. Then, the sheet metal 2 can also serve as a shield top plate, and the effect of an electromagnetic wave shield frame is born. Further, since the metals are connected to each other, the sheet metal and the shield frame are thermally connected, and sufficient heat dissipation from the circuit components to the sheet metal via the shield frame is possible due to the high thermal conductivity of the metal.

  In addition, since the projection part 7 and the sheet metal 2 are fitted together, it is preferable that the material has a certain degree of elasticity. When it is desired to further promote heat dissipation from the circuit component 8 to the shield frame 4, a grounded metal region for heat dissipation is formed between the circuit component 8 and the shield frame 4 on the substrate 3 within a range that does not affect the operation. An insulating heat radiation sheet may be formed.

  The sheet metal 2 formed integrally with the housing not only protects the screen display but also serves as a shield top plate, so there is no need to provide a separate top surface. As shown in the cross section of FIG. Can be made thinner and the number of parts can be reduced. FIG. 6A is a cross section when the shield top plate 40 and the sheet metal 2 are separated.

  In addition, since the shield frame of the substrate is connected to the metal plate of the housing with the metal, the heat of the substrate is transmitted to the metal plate of the housing with the metal thermal conductivity. For this reason, in order to improve thermal conductivity, an object is usually sandwiched between the metal plate of the housing and the shield frame. However, due to tolerance deviations such as component height and solder float, the thickness is not constant, and cushioning materials must be sandwiched. I didn't. In this embodiment, the heat of the substrate is made of metal (up to 428 [W / m · k]) higher than that of the cushioning material having a thermal conductivity of about 10 [W / m · k]. 1 can dissipate heat.

  Further, since the sheet metal and the shield frame are directly fitted, the cushion itself described in the background art becomes unnecessary. Therefore, the thickness and cost for the cushion can be reduced.

  Furthermore, since the metal plate 2 and the shield frame 4 of the housing 1 are connected by metal, the substrate 3 and the metal plate 2 are connected to the ground. Therefore, it is not necessary to ground the sheet metal 2 to the ground separately in the vicinity of the shield frame 4, and the components and the mounting area can be reduced.

In this embodiment, the metal plate 2 is provided with the hook 5 and the shield frame 4 is provided with the projection 7 and the metal plate 2 and the shield frame 4 are engaged. On the contrary, the metal plate 2 is provided with the projection 7 and the shield frame 4 is hooked. 5 may be provided.
(Second Embodiment)
The second embodiment will be described with reference to FIGS. In the second embodiment, the engagement portion provided on the substrate and the engagement plate formed on the sheet metal 2 are engaged.

  A required number (seven in FIG. 7) of on-board clips 20 that can hold and contact the end of the sheet metal on the substrate 3 like a clip is mounted on the substrate 3. On the other hand, the hook 5 and the engagement hole 51 are not provided in the sheet metal 2. As shown in FIG. 8, the sheet metal 2 is pressed to provide a rectangular insertion plate 9 that stands vertically.

When the substrate 1 is assembled into the housing 1 by the same operation as that of the embodiment, the insertion plate 9 is inserted into the on-board clip 20 to constitute a clip type shield frame. In the example of FIG. 8, the insertion plate 9 appears to fly away, but if a metal plate (not shown) is formed between the insertion plates 9 to form a gap, there can be no gap.
(Third embodiment)
When it is desired to increase the contact surface between the sheet metal 2 and the shield frame 4, in addition to the hook 5 described in the first embodiment, a protruding contact portion 10 may be added to the sheet metal 2 as shown in FIG. The contact portion 10 is a hemispherical protrusion and has a role of contacting the side surface of the shield frame 4.

  By bringing the contact portion 10 into contact with the side surface of the shield frame 4, the contact area between the sheet metal 2 and the shield frame 4 can be further expanded, and the amount of heat conduction can be increased and the ground connection can be enhanced. In FIG. 9, six contact portions are formed for seven hooks.

  When the hook 5 is provided on the shield frame 4 side, the contact portion 10 may also be provided on the shield frame 4 side so that the contact portion is brought into contact with the sheet metal 2. The contact portion 10 is provided on the sheet metal 2, and the contact portion is provided. May be brought into contact with the shield frame 4.

  The present invention can be used for a mobile phone, a smartphone, a tablet terminal, a personal computer, a flat-screen television, and the like. In particular, the display screen can be used for an electronic device having almost the same size as the entire device.

DESCRIPTION OF SYMBOLS 1 Housing | casing 2 Sheet metal 3 Circuit board 4 Shield frame 5 Hook 6 Positioning hook 7 Protrusion part 9 Insertion board 8 Circuit component 10 Contact part 20 On-board clip 40 Shield top plate 51 Engagement hole 53 Slit 100 Display device

Claims (9)

  An electronic device provided with a display screen, wherein a substrate on which a component that releases heat is mounted, a shield frame provided on the substrate, a screen display protection sheet metal, the screen display protection sheet metal, and at least one of the shield frame An engaging portion that engages both the screen display protection sheet metal and the shield frame to thermally connect them, and the screen display protection sheet metal covers the shield frame. An electronic device having a display screen, which is also used as a plate.   3. The electronic device having a display screen according to claim 1, wherein the engagement between the screen display protection sheet metal and the shield frame has a contact area capable of releasing heat from the component to the screen display protection sheet metal. .   The engaging portion includes a protrusion formed on one of the shield frame and the screen display protection sheet metal, and an engagement formed on the other of the shield frame and the screen display protection sheet metal to engage with the protrusion. The electronic device provided with the display screen according to claim 1 which is a hole.   The electronic device provided with the display screen according to claim 3, wherein a plurality of the protrusions and the engagement holes are provided in one shield frame or one screen display protection sheet metal.   The electronic device provided with the display screen according to any one of claims 1 to 4, wherein a contact portion that contacts the shield frame is provided on the screen display protection sheet metal.   An electronic device including a display screen, on which a substrate on which a component that releases heat is mounted, at least one engaging portion provided on the substrate, and a member that engages with the engaging portion to become a shield frame A screen display protection sheet metal having a plywood, the screen display protection sheet metal and the substrate are engaged with the engagement portion and the engagement plate to thermally connect the screen display protection sheet metal to the engagement portion; An electronic apparatus having a display screen, wherein the screen display protection sheet metal is also used as a shield top plate for covering the shield frame.   The said engagement part is an on-board clip provided with two or more on the said board | substrate, The said engagement board is an insertion board provided on the said screen display protection sheet metal, and is inserted in the said on-board clip. An electronic device with a display screen.   The electronic device with a display screen according to any one of claims 1 to 7, wherein the display screen is provided on a side opposite to the substrate with the screen display protection sheet metal interposed therebetween.   The electronic device having a display screen according to any one of claims 1 to 8, wherein a size of the display screen is substantially the same as a size of the electronic device.

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