JP2006352618A - Mobile terminal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile terminal device capable of supporting an IC with respect to key pressure without need to attach an independent spacer like a sheet. <P>SOLUTION: In the mobile terminal device, a shield case (shield member) 19 is mounted at a position to cover a plurality of integrated circuit parts (IC) 16 on a substrate 15 disposed within cases 10a, 10b with the plurality of integrated circuit parts 16 packaged thereon. The shield case 19 includes projecting portions 42x, 42y, 42z protruding to each of the plurality of integrated circuit parts 16 in the state of being mounted on the substrate 15, and the distal ends of these projecting portions are abutted on surfaces of the integrated circuit parts 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a portable terminal device having a plurality of keys operated by a user on the surface of a housing.

  A board of an apparatus having a button on the surface of a housing such as a cellular phone terminal that is pressed by a user usually has a sheet key arranged on one side and an electronic component such as an IC arranged on the back side.

  Conventionally, the key pressure test is performed in the reliability evaluation, and the test is to check whether the internal components and the substrate are not damaged by applying a pressing force to each key that is larger than the normal use state. It is. Even if it is the backside of the board, if a blank part occurs due to the variation in the height of multiple ICs, a local force acts on the board by pressing the key, so the board bends and bends, causing the IC to Operation failure occurs due to peeling or poor contact of electrical contacts.

  Conventionally, as a countermeasure, a sheet whose size and thickness are adjusted to absorb the difference in height of each IC is attached to the surface of the IC as a spacer, and these sheet surfaces are passed through a shield case or the like. It was intended to be received on a flat, hard surface such as a battery.

Japanese Patent Application Laid-Open No. H10-260260 discloses a technique for radiating heat by forming a convex portion on a shield case by drawing and bringing it into contact with an electronic component through thermally conductive grease or the like.
JP-A-5-63383

  In recent mobile phone terminals, a relatively large number of ICs are used due to high functionality and multi-functionality, and the heights of these ICs vary. The above-mentioned measures for adhering a sheet to the space formed between the IC and the shield case require preparing and adhering sheets of different sizes and thicknesses in accordance with the ICs. In addition, there is a problem that man-hours for sheet pasting are required.

  The technique described in Patent Document 1 shows that a heat radiation effect is obtained by bringing a convex portion formed by drawing into a shield case into contact with an electronic component through grease or the like. On the other hand, no consideration is given to the mechanical support of the electronic component by the shield case.

  The present invention has been made in such a background, and provides a portable terminal device that can support an IC against a key press without the need of attaching an independent spacer such as a sheet.

  A mobile terminal device according to the present invention is a mobile terminal device having a plurality of keys on a surface of a housing, the substrate being disposed in the housing and mounting a plurality of integrated circuit components, and the plurality of integrated circuits on the substrate. And a shield member attached to a position covering the component. The shield member has a protrusion protruding from each of the plurality of integrated circuit components in a state of being attached to the substrate, and a tip of the protrusion contacts the surface of the plurality of integrated circuit components. With this configuration, the space between the back side surface of the shield member and the surface of the integrated circuit component is filled with the convex portion in a state where the shield member is attached to the substrate, so that local pressure due to key pressing is applied to the substrate. Even if it is applied, the pressing force is supported via the shield member. This prevents the substrate from being bent or curved without using an independent spacer such as a sheet, and as a result, adverse effects on the integrated circuit components are prevented.

  By varying the height of the convex portion according to the height from the surface of the substrate to the surfaces of the plurality of integrated circuit components, variations in the heights are absorbed.

  If the convex portion has a substantially square or circular shape for a relatively small integrated circuit component and a more complicated shape for a relatively large integrated circuit component, Support for large-sized integrated circuit components is ensured.

  According to the present invention, the shield member is provided with a convex portion that protrudes with respect to each of the plurality of integrated circuit components on the substrate, and the tip thereof is configured to contact the surface of the integrated circuit component. This eliminates the need to use a separate sheet and reduces the number of pasting steps. Providing convex portions on the shield member also increases the surface area, which is effective for heat dissipation of the integrated circuit components.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.

  FIG. 1 is a plan view showing an appearance of an operation unit of a mobile phone terminal as an example of the mobile terminal device of the present invention. In this example, a front case 10a of a lower case of a foldable mobile phone terminal is shown. Here, an example of the folding type is shown, but other forms such as a straight type and a slide type may be used.

  Various types of keys 11 such as a numeric keypad, a manner key, a memo key, a power / end key, a call key, a clear key, a cursor operation key, a mail key, a Web key, an application key, and a phone book key are provided on the operation unit of the mobile phone terminal. Is arranged.

  FIG. 2 is a plan view showing a schematic appearance of the substrate 15 behind the front housing 10a of FIG. The substrate 15 is a printed wiring board on which electronic components including a plurality of integrated circuits (ICs) are mounted on at least the back surface. As shown in FIG. 2, a sheet key 14 is attached to the surface of the substrate 15. The sheet key 14 includes a dome-shaped contact 14 a arranged at a position corresponding to each key in FIG. 1 and an insulating sheet 14 b covering these, and the insulating sheet 14 b is bonded to the substrate 15. The dome-shaped contact 14a is formed of a conductive elastic member that is deformed by pressing and has a concave top portion and returns to its original shape by elastic force when the pressing force is removed, and a fixed contact 15a provided on the substrate 15; Form a switch between.

  FIG. 3 shows a schematic appearance of the back side of the substrate 15 shown in FIG. As can be seen from this figure, a plurality of ICs 16 a to 16 k are mounted on the substrate 15 together with the connectors 31, 32 and the like. The height from the substrate surface when these ICs are mounted on the substrate 15 varies. In this example, two sets of IC groups are each surrounded by shield frames 17 and 18 on which a shield case (described later) for preventing leakage of electromagnetic waves is attached on the substrate 15. The height of the shield frames 17 and 18 is set to be equal to or higher than the highest IC among the plurality of ICs.

  FIG. 4 shows a state where shield cases 19 and 20 as shield members of the present invention are attached to the shield frames 17 and 18 of the substrate 15 shown in FIG. In this example, the “case” does not have a box shape but is a substantially plate-like cover having conductivity. The shield case of the present embodiment is made of a metal such as stainless steel or aluminum.

  As shown in FIG. 4, the shield cases 19 and 20 are formed with recesses 41 a to 41 e and 41 g to 41 k corresponding to the positions of the ICs 16 a to 16 e and 16 g to 16 k on the surface when viewed from above. . These concave portions are convex portions protruding from the back surfaces of the shield cases 19 and 20, and when the shield cases 19 and 20 are correctly attached to the shield frames 17 and 18, the tip portions of the convex portions correspond to the corresponding portions. The height of the convex portion (that is, the depth of the concave portion) is set so as to contact the surface of the IC. Such irregularities can be formed by, for example, metal drawing. In this example, no convex portion corresponding to the IC 16f is provided. This indicates that it is not always necessary to provide a convex portion for every IC. As such a case, a case where there is no influence of the key press depending on the size and position of the IC, or a case where the IC is high enough to contact the back side of the shield case without a convex portion is assumed.

  FIG. 5 shows a state in which the rear housing 10b is covered from the top of the substrate 15 shown in FIG. The rear housing 10b is provided with an opening 50 through which the shield case 19 is exposed, and a battery is mounted thereon. The battery contact is connected to a battery contact 23 provided on the rear housing 10b when the battery is mounted. In practice, a sheet (not shown) on which the name of the communication carrier, the date of manufacture, the serial number, etc. are written is affixed so that the surface of the shield case 19 is not directly exposed.

  FIG. 6 shows a state in which the battery cover 22 is attached to the rear housing 10b of FIG.

  FIG. 7 shows a configuration example of the shield case 19 as a specific configuration of the shield case. 7A is a plan view of the shield case 19, FIG. 7B is a left side view, FIG. 7C is a right side view, and FIG. 7D is a cross-sectional view taken along line AA ′ of FIG. FIG. 7 (e) is a bottom view, and FIG. 7 (d) is a cross-sectional view taken along the line BB ′ of FIG. 7 (a). On the surface of the shield case 19, the above-described concave portions 41a to 41e and 41g are formed. As can be seen from FIGS. 7D and 7F, the depth of the recesses is different for each recess. In addition, the periphery except the right side surface of the shield case 19 has an edge portion standing upright from the main surface of the shield case 19, and a plurality of openings 43 at the edge portion are provided. The right side surface has no edge for convenience of mounting, and the opening 43 engages with a corresponding convex portion (not shown) provided in the shield frame 17 to prevent the shield case from being detached. It is. However, the edge and opening of the shield case are not essential elements in the present invention, and the specific shape, number, etc. thereof are not particularly limited.

  The shape of the concave portion viewed from the front surface side of the shield case in this embodiment (that is, the shape of the convex portion viewed from the back side) differs depending on the size of the corresponding IC. That is, the recess has a substantially square or circular shape for relatively small integrated circuit components and a more complex shape for relatively large integrated circuit components. In this example, a complicated shape is a stitch shape in which linear concave portions are interlaced. This is because if the concave portion having a rectangular shape is used for a relatively large size IC, the size of the continuous flat portion becomes too large, and the strength for supporting the IC against the key press decreases. The shape of the recess for a relatively large size IC is not limited to a stitch shape, and may be any shape as long as the strength for supporting the IC does not decrease. For example, a zigzag shape, a lattice shape, a spiral shape, a polka dot shape, a plurality of donut shapes, and the like may be used. These common properties are that the length of the continuous flat portion in an arbitrary direction is smaller than a predetermined value.

  Note that the shield case 20 shown in FIG. 4 is supported by ribs (not shown) formed on the rear housing 10b. Usually, since the surface of the battery 21 is hard and flat, the battery is more suitable for supporting a shield case in which a concave portion is formed than a rib. However, in the present embodiment, the shield case 20 is smaller in size than the shield case 19 and the IC size is also small, so that a rib is sufficient for supporting the shield case. Therefore, such a rib can also function as “another terminal component” for supporting the shield member in the present invention.

  FIG. 8 is an exploded cross-sectional view of the housing according to the present embodiment as viewed from the side thereof. (However, the IC 16 and the shield case 19 in this figure do not strictly correspond to the specific parts described above.) From the top, the front casing 10a, the button key 12, the sheet key 14, the board 15, and the shield case 19 are sequentially arranged. The rear housing 10b, the battery 21 and the battery cover 22 are shown. The button key 12 includes an elastic sheet 13 and a key 11 (button) attached to a predetermined position on the elastic sheet 13 (a position corresponding to the opening 10c of the front housing 10a).

  The shield case 19 is attached to the shield frame 17 around the IC 16 mounted on the substrate 15, and the tip portions of the convex portions 42x, 42y, and 42z protruding from the back side of the concave portions 41x, 41y, and 41z correspond to the IC. It can be seen that it is configured to abut against the surface. That is, the IC is directly supported by the shield case 19 via the convex portions 42x, 42y, and 42z, and the shield case 19 is directly supported by the flat portion of the battery 21 accommodated in the terminal. The battery 21 is accommodated in the opening by a known locking mechanism so as not to be detached from the rear housing 10 b and is covered with the battery cover 22.

  With the configuration as described above, even if a force is locally applied to the substrate 15 by pressing the key 11, each part of the substrate 15 is reliably secured by the shield case structure itself without using a sheet as a spacer as in the prior art. Therefore, it does not cause bending or bending, and it is possible to prevent adverse effects on each IC connection portion mounted on the substrate 15. As a result, it is possible to prevent the occurrence of defects such as IC peeling and breakage and poor contact. Further, since the strength of the shield case itself is increased, not only the key is pressed but also the resistance against an impact when the terminal is dropped is increased. Furthermore, a heat dissipation effect due to an increase in the surface area of the shield case can be expected. By forming unevenness by forming the shield case by deformation of the metal plate, the weight of the shield case itself is the same as when there is no unevenness. Therefore, according to the present embodiment, the weight of the terminal can be reduced by the weight of an independent sheet as in the prior art.

  FIG. 9 shows another embodiment of the present invention. In the first embodiment described above, the IC shielded by the shield case is mounted only on one surface side of the substrate 15, but the example of FIG. 9 shows the case where the IC 56 is mounted on the other surface side of the substrate 15. ing. Therefore, similarly to the shield case 19, the IC 56 is provided with a shield case 59 in which the height of the convex portion (depth of the concave portion) is varied depending on the height of the IC. The shield frame 57 is attached. A flexible substrate 58 is provided on the shield case 59 as another substrate, and the sheet key 14 is disposed thereon. The flexible board 58 is connected to the main board 15 via a connector (not shown). Detection of key press is performed via the flexible substrate 58. Since the other configuration of the present embodiment is the same as that of the first embodiment, redundant description is omitted.

  In the second embodiment, the same effect as that of the first embodiment can be obtained. Furthermore, since the second embodiment can mount more ICs on both sides of the substrate 15, it is suitable for use in a mobile phone terminal corresponding to high functionality and multi-function.

  The preferred embodiments of the present invention have been described above, but various modifications and changes other than those mentioned above can be made.

  For example, although the mobile phone terminal has been described in the above description, the present invention can be applied to any mobile terminal device having operation keys.

  The shield case is made of a metal such as stainless steel or aluminum. However, the shield case may be a plastic molded into a predetermined shape and coated with conductive plating or foil.

  The shield case, which is a shield member, is attached to the substrate via the shield frame. However, the shield frame is not necessarily an essential element, and the shield case may be directly attached to the substrate.

It is a top view which shows the external appearance of the operation part of the mobile telephone terminal as an example of the portable terminal device of this invention. FIG. 2 is a plan view showing a schematic appearance of a substrate behind the front housing of FIG. 1. It is a figure which shows the outline external appearance of the back side of the board | substrate shown in FIG. FIG. 4 is a diagram showing a state where shield cases are attached to the shield frames in the substrate shown in FIG. 3. It is the figure which showed the state which covered the back housing | casing 10b from the board | substrate 15 shown in FIG. It is a figure which shows the state in which the battery cover was attached with respect to the back housing | casing of FIG. It is a figure which shows the structural example of the shield case 19 shown in FIG. It is the exploded sectional view which looked at the case in the embodiment of the present invention from the side. It is an exploded sectional view showing other embodiments of the present invention.

Explanation of symbols

10a ... front housing, 10b ... back housing, 10c ... opening, 11 ... key (button), 12 ... button key, 13 ... elastic sheet, 14 ... sheet key, 14a ... dome-shaped contact, 14b ... insulating sheet, 15 DESCRIPTION OF SYMBOLS ... Board | substrate, 15a ... Fixed contact, 16 ... Integrated circuit component, 17, 18 ... Shield frame, 19 ... Shield case, 20 ... Shield case, 21 ... Battery, 22 ... Battery cover, 23 ... Battery contact, 31 ... Connector, 41a to 41e, 41g ... concave portion, 42x, 42y, 42z ... convex portion, 43 ... opening, 50 ... opening, 57 ... shield frame, 58 ... flexible substrate, 59 ... shield case

Claims (6)

A portable terminal device having a plurality of keys on the surface of a housing,
A substrate mounted in the housing and mounted with a plurality of integrated circuit components;
A shield member attached to a position covering the plurality of integrated circuit components on the substrate;
The shield member has a convex portion protruding from each of the plurality of integrated circuit components in a state of being attached to the substrate, and a tip of the convex portion is in contact with a surface of the plurality of integrated circuit components. The portable terminal device characterized by this.   The portable terminal device according to claim 1, wherein the height of the convex portion varies depending on a height from a surface of the substrate to a surface of the plurality of integrated circuit components.   The portable terminal device according to claim 1, wherein the shield member is supported by another terminal component.   The convex portion has a substantially square or circular shape for a relatively small integrated circuit component, and has a more complicated shape for a relatively large integrated circuit component. The mobile terminal device according to claim 1.   The mobile phone according to claim 4, wherein the more complicated shape of the convex portion is an arbitrary shape in which a length of a continuous flat portion in an arbitrary direction on the surface of the shield member is smaller than a predetermined value. Terminal device.   The portable terminal device according to claim 1, wherein the shield member is formed by drawing a metal plate.

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