WO2004023765A1

WO2004023765A1 - Portable electronic product with waterproof structure and waterproofing method thereof

Info

Publication number: WO2004023765A1
Application number: PCT/KR2003/001831
Authority: WO
Inventors: Yong Jhee; Sang-Choon Lee
Original assignee: Watercom Co., Ltd.
Priority date: 2002-09-06
Filing date: 2003-09-05
Publication date: 2004-03-18
Also published as: AU2003258881A1

Abstract

A portable electronic product having a waterproof structure and a waterproofing method thereof are provided. The portable electronic product having a waterproof structure having a casing defining an accommodating space inside, and a built-in component assembly having a waterproofing portion to be avoided from contacting with water or moisture, and accommodate in and combined with the casing, the portable electronic product includes a core frame combined with the built-in component assembly along the outer periphery of the built-in component assembly so as to enclose the waterproofing portion of the built-in component assembly, and a resin molded article contracting and connected with the core frame on the outer surface of the core frame so as to prevent external water or moisture from infiltrating into the waterproofing portion. Therefore, the portable electronic product having ensured waterproofing capability allows water or moisture to be prevented from infiltrating into built-in circuit components even after being exposed to water, without a considerable increase in manufacturing cost nor an adverse effect on designing of a casing.

Description

PORTABLE ELECTRONIC PRODUCT WITH WATERPROOF STRUCTURE AND WATERPROOFING METHOD THEREOF

Technical Field The present invention relates to a portable electronic product having a waterproof structure and a waterproofing method thereof, and more particularly, to a portable electronic product having a waterproof structure by which the device can operate normally even after it is exposed to water, and a waterproofing method of the portable electronic product.

Background Art

A portable electronic product, for example, a mobile phone, a personal digital assistant (PDA), a notebook computer, a liquid crystal display (LCD) TV, a portable wireless apparatus, a compact disc (CD) player, and an MPEG1 audio layer-3 (MP3) player, can be freely used while moving, without regard to a place. The portable electronic product may happen to be exposed to water on carrying. For example, the portable electronic product may happen to be dropped into water, or get wet in the rain. Since most of the devices do not adopt a waterproof design, water may infiltrate into circuit components provided within their casings. Accordingly, the portable electronic products may lose their functions by the circuit components exposed to water or moisture, so that they are liable to malfunction. In this regard, it is necessary to prevent these problems. Also, portable electronic products that can be conveniently used without regard to place, even at a wet place, e.g., beach or a bath, are preferred. Therefore, there is increasing demand for a portable electronic product having a waterproof structure by which their circuit components can be protected against water or moisture by preventing water or moisture from infiltrating into the circuit components even after the portable electronic product is exposed to water or moisture.

However, since most conventional portable electronic products, particularly, most mobile phones, do not adopt a waterproof design, they are susceptible to abnormal operation or damages when they are exposed to water. To overcome such problems, there have been proposed a few portable electronic products having a waterproof design.

In such conventionally proposed waterproofing methods, a hermetic seal is generally established in gaps of a casing, the gaps through which moisture may infiltrate into the electronic product. However, since it is practically difficult to hermetically seal all the gaps, sufficient waterproofing cannot be achieved. Also, the hermetical seal of all the gaps may give rise to an increase in the size of a portable electronic product, causing many limitations in external design of portable electronic products and increasing development cost and manufacturing cost, which is not desirable in view of cost efficiency and marketability.

Disclosure of the Invention

The present invention provides a portable electronic product having a waterproof structure and a waterproofing method thereof, which can prevent water or moisture from infiltrating into a built-in circuit component assembly even after being exposed to water, without a considerable increase in manufacturing cost nor an adverse effect on designing of a casing. According to an aspect of the present invention, there is provided a portable electronic product having a waterproof structure having a casing defining an accommodating space inside, and a built-in component assembly having a waterproofing portion to be avoided from contacting with water or moisture, and accommodated in and combined with the casing, the portable electronic product comprising: a core frame combined with the built-in component assembly along the outer periphery of the built-in component assembly so as to enclose the waterproofing portion of the built-in component assembly; and a resin molded article contacting and connected with the core frame on the outer surface of the core frame so as to prevent external water or moisture from infiltrating into the waterproofing portion.

Here, the resin molded article may be injection molded to a predetermined thickness using the built-in component assembly to which the core frame is coupled, as an insert, and may be combined with the core frame during injection molding.

To advantageously protect circuit components of the built-in component assembly during injection molding and to more efficiently utilize a space required for architecture of a portable electronic product by obviating a necessity for separate design for shielding electromagnetic interference, the portable electronic product may further comprise a heat-insulating and shock-absorbing member installed between the core frame and the built-in component assembly, for insulating heat and absorbing shocks from the built-in component assembly; and an electromagnetic shielding sheet installed between the heat-insulating and shock-absorbing member and the core frame, for shielding electromagnetic interference. Here, the heat-insulating and shock-absorbing member is preferably an ethylene vinyl acetate (EVA) sponge.

Also, the resin molded article is an elastomer mold, which is because elastomer is fused well into a plastic surface during injection molding, thereby maintaining high adhesiveness and airtightness.

Shock-absorbing protrusions protruding outward from the outer surface of the resin molded article are preferably provided on some regions of the outer surface of the resin molded article, for the purpose of protecting built-in circuit components by absorbing external shocks that may be applied after the built-in component assembly is installed in the casing. Also, a cutting line for cutting the resin molded article may be formed on the outer surface of the resin molded article. The reason of forming the cutting line is to facilitate removal of the resin molded article in a case where a repairing work can be performed by removing the resin molded article, rather than by replacing the overall built-in component assembly in an event of malfunctioning. A flow channel inwardly recessed to a predetermined depth may be formed on the outer surface of the core frame for the purpose of facilitating smooth flow of the resin during injection molding, and reinforcing ribs for reinforcing the strength of the core frame may be prepared on some regions of the internal surface of the core frame.

Preferably, the resin molded article is vacuum-molded so as to have an internal shape corresponding to an external shape of the built-in component assembly and is then combined with the core frame.

Also, the resin molded article is preferably combined with the core frame by ultrasonic fusion, which is advantageous in view of working efficiency.

The portable electronic product may further comprise a rubber-painted layer coated on at least some regions of the outer surface of the resin molded article, thereby ensuring waterproofing performance.

The core frame may comprise an upper core frame and a lower core frame facing and coupled to each other, and the resin molded article may comprise an upper resin molded article and a lower resin molded article that are combined with the upper core frame and the lower core frame by ultrasonic fusion, respectively. An engagement protrusion may be formed along the periphery of the peripheral portion of one of the upper and lower core frames, and an engagement groove corresponding to the engagement protrusion may be formed along the periphery of the peripheral portion of the other of the upper and lower core frames of the lower core frame.

At least one of the upper and lower core frames may have at its distal end a sloping portion whose external side is inclined such that the thickness thereof is thinner outward. In such a manner, a wedge-shaped groove is formed at a connecting portion of the upper and lower core frames. Thus, when the resin molded article is to be removed in an event of malfunctioning of the built-in component assembly, the resin molded article can be easily cut away along the wedge-shaped groove.

According to another aspect of the present invention, there is provided a waterproofing method of a portable electronic product having a casing defining an accommodating space inside, and a built-in component assembly having a waterproofing portion to be avoided from contacting with water or moisture, and accommodated in and combined with the casing, the waterproofing method comprising: combining a core frame with the built-in component assembly along the outer periphery of the built-in component assembly so as to enclose the waterproofing portion of the built-in component assembly; and performing injection molding of a resin molded article to a predetermined thickness on the outer surface of the core frame and at least some regions of the outer surface of the built-in component assembly using the built-in component assembly combined with the core frame as an insert to prevent water or moisture from infiltrating into the waterproofing portion of the built-in component assembly.

Here, the built-in component assembly may further comprise a protection portion to be avoided from contacting with an injection mold during injection molding, and the waterproofing method may further comprise installing a protection member configured to contact with the injection mold during injection molding, on the protection portion of the built-in component assembly before the resin molded article is integrally injection-molded with the core frame and the built-in component assembly, and removing the protection member after the injection molding is completed. Preferably, the combining of the core frame with the built-in component assembly is preceded by installing an electromagnetic shielding sheet in the core frame so as to prevent electromagnetic interference, and installing a heat-insulating and shock-absorbing member on the core frame so as to contact with the outer surface of the electromagnetic shielding sheet.

According to another aspect of the present invention, there is provided a waterproofing method of a portable electronic product having a casing defining an accommodating space inside, and a built-in component assembly having a waterproofing portion to be avoided from contacting with water or moisture, and accommodated in and combined with the casing, the waterproofing method comprising: preparing a core frame combined with the built-in component assembly along the outer periphery of the built-in component assembly so as to enclose the waterproofing portion of the built-in component assembly; preparing a resin molded article having an internal shape corresponding to an external shape of the core frame to a predetermined thickness by vacuum molding; combining the resin molded article with the core frame; and combining the built-in component assembly with the core frame combined with the resin molded article. The waterproofing method may further comprise forming a rubber-painted layer on at least some regions of the outer surface of the resin molded article after the combining of the built-in component assembly with the core frame.

The resin mode is preferably made of a transparent polyester resin, which is advantageous in that a display screen is not obstructed even when the resin molded article is arranged on a LCD portion of the portable electronic product, such as a mobile phone. Also, the resin molded article is preferably combined with the core frame by ultrasonic fusion. The core frame may comprise an upper core frame and a lower core frame facing each other, and the resin molded article comprises an upper resin molded article and a lower resin molded article that are combined with the upper core frame and the lower core frame by ultrasonic fusion, respectively. Also, the core frame may be configured such that an engagement protrusion is formed along the periphery of the peripheral portion of one of the upper and lower core frames, and an engagement groove corresponding to the engagement protrusion is formed along the periphery of the peripheral portion of the other of the upper and lower core frames of the lower core frame.

Brief Description of the Drawings

The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: FIG. 1 is a partly cut-away perspective view of a mobile phone according to an embodiment of the present invention;

FIG. 2 is a plan view of a built-in component assembly shown in FIG. 1 ;

FIG. 3 is a right side view of a body built-in component assembly shown in FIG. 2;

FIG. 4 is a right side view of a flip built-in component assembly shown in FIG. 2;

FIG. 5 is a detailed diagram of a flexible connector shown in FIG. 2; FIG. 6 is a plan view of a built-in component assembly of a mobile phone according to another embodiment of the present invention;

FIG. 7 is a right side view of a body built-in component assembly shown in FIG. 6; FIG. 8 is a right side view of a flip built-in component assembly shown in FIG. 6;

FIG. 9 is a plan view of an upper resin molded article combined with the flip built-in component assembly shown in FIG. 8;

FIG. 10 is a left side view of the upper resin molded article shown in FIG. 9;

FIG. 11 is a plan view of a lower resin molded article combined with the flip built-in component assembly shown in FIG. 8; and

FIG. 12 is a left side view of the lower resin molded article shown in FIG. 11.

Best mode for carrying out the Invention

The present invention can be applied to various portable electronic products such as a mobile phone, PDA, a notebook computer, an LCD TV, a portable wireless apparatus, a CD player, and an MP3 player, specifically portable electronic products having a casing defining an accommodating space inside, and a built-in component assembly having a waterproofing portion, which must avoid contacting with water or moisture, and accommodated in and combined with the casing. A mobile phone adopted in the present invention will now be described in detail by way of example.

FIG. 1 is a partly cut-away perspective view of a mobile phone according to an embodiment of the present invention, and FIG. 2 is a plan view of a built-in component assembly shown in FIG. 1. As shown in the drawings, a mobile phone 1 according to an embodiment of the present invention includes a casing 10, a built-in component assembly 20, a core frame 30, an ethylene vinyl acetate (EVA) sponge 50, an electromagnetic shielding sheet 60, and an elastomer 40. The casing 10 has an accommodating space defined therein, and the built-in component assembly 20 has a waterproofing portion, which must avoid contacting with water or moisture, and is accommodated in and combined with the casing 10. The core frame 30 is combined with the built-in component assembly 20 so as to enclose the waterproofing portion of the built-in component assembly 20. The EVA sponge 50 is installed between the core frame 30 and the built-in component assembly 20 as a heat-insulating and shock-absorbing member. The electromagnetic shielding sheet 60 is installed between the EVA sponge 50 and the core frame 30. The elastomer 40 is a resin molded article that is integrally injection-molded with the core frame 30 and the built-in component assembly 20 and installed on the outer surface of the core frame 30.

The casing 10 has a body casing 1 1 , in which a plurality of signal input buttons 23a are installed as a user's data input device, and a flip casing 15, in which an LCD is installed. A body built-in component assembly 21 , which has built-in components incorporated in the body casing 1 1 and will be described later, is accommodated in and combined with the body casing 11 , and a flip built-in component assembly 25, which has built-in components incorporated in the flip casing 15 and will be described later, is accommodated in and combined with the flip casing 15. The body casing 11 includes button holes 12 formed at positions of the plurality of signal input buttons 23a so that the plurality of signal input buttons 23a can be exposed outside, and a connecting portion 13 hinged to the flip casing 15. The flip casing 15 includes a display portion 16 hollowed out such that an LCD 26 can be exposed outside, and a hinge connector 17 hinged to the body casing 1 1 . The flip casing 15 is opened or closed by rotating relative to the body casing 11 about a lengthwise axis corresponding to the centerline of the hinge connector 17.

FIG. 3 is a right side view of the body built-in component assembly shown in FIG. 2, FIG. 4 is a right side view of the flip built-in component assembly shown in FIG. 2, and FIG. 5 is a detailed diagram of a flexible connector shown in FIG. 2, respectively. The built-in component assembly 20, which are illustrated in FIGS. 2 through 5, generally includes a printed circuit board (PCB) 22, 28, and functional components electrically connected to and combined with the PCB 22, 28, such as, an internal antenna jack 22a, an earphone jack 22b, an external antenna jack 22c, a contact point 22d, a speaker 27 and so on. The term "built-in component assembly" used throughout the specification means a finished component assembly, all components of which have been inspected whether they operate normally or not after being assembled. Unlike the conventional mobile phone with a waterproof structure in which various gaps of a casing of a mobile phone are sealed, the mobile phone according to an embodiment of the present invention employs a new waterproof structure in which a portion of the built-in component assembly 20, excluding portions to be exposed outside, e.g., portions connected to external devices, is enclosed by an injection-mold resin, e.g., a material such as the elastomer 40 so that water can be prevented from infiltrating into built-in circuit components of the built-in component assembly 20. In the folder-type mobile phone 1 as in the above-described embodiment of the present invention, the built-in component assembly 20 is largely divided into a built-in component assembly 21 incorporated in the body casing 11 , and a built-in component assembly 25 incorporated in the flip casing 15, which will be separately defined as the body built-in component assembly 21 and the flip built-in component assembly 25, respectively, for clarity. However, it should be noted that the respective built-in component assemblies, which are both finished built-in component assemblies whose components are all inspected whether they operate normally or not after being assembled, correspond to the built-in component assembly 20 defined above. Thus, it can be easily understood that a portable electronic product, such as a flip-type mobile phone, has a built-in component assembly, designated by reference numeral 20 in the present invention, having a body built-in component assembly and a flip built-in component assembly integrally formed therein, each designated by reference numeral 21 , 25 in the present invention, and an elastomer injection mold can be applied thereto.

The body built-in component assembly 21 includes a body PCB 22 and a keypad unit 23 provided in front of and electrically connected to the body PCB 22. The keypad unit 23 is a part where the signal input buttons 23a are installed for user's data input. In the body built-in component assembly 21 , since water cannot infiltrate into the body PCB 22 even though a surface of the keypad unit 23 is exposed to water, it is not necessary to arrange the core frame 30 and the elastomer 40 as a resin molded article on the outer surface of the keypad unit 23. Therefore, in the surface of the body built-in component assembly 21 , the surface of the keypad unit 23, an edge of the contact point 22d and an edge of the external antenna 22c, which are connected to external devices, are excluded from portions to be waterproofed, so that the elastomer 40 is not formed thereat. A waterproof contact point, as disclosed in the Korean Utility Model No. 198490 titled "Terminal Structure with Waterproof Structure" owned by the present applicant, is used as the contact point 22d. The insides of the external antenna 22c and the earphone jack 22b are treated using well-known waterproofing technology. In the flip built-in component assembly 25, the speaker 27 and the LCD 26 are electrically connected to the LCD PCB 28. Since water cannot infiltrate into the PCB 28 of the LCD 26 even though a glass surface of the LCD 26 is exposed to water, it is not necessary to perform waterproofing on the glass surface of the LCD 26. Also, edges of a contact point to be connected to a flexible connector 29 to be described later are excluded from portions to be treated with waterproofing. The keypad unit 23 in the built-in component assembly 20, and the glass surface of the LCD 26, which are excluded from portions to be treated with waterproofing, are injection-molded after being covered by a separate protection member 39 during injection molding, which will later be described.

In the flexible connector 29 provided in a folder-type mobile phone, for connecting the body built-in component assembly 21 with the flip built-in component assembly 25, since an edge of a contact point should be exposed for electrical connection, the elastomer 40 is not formed thereat.

The core frame 30 is combined with the built-in component assembly 20 so as to enclose the waterproofing portion of the built-in component assembly 20. Generally, the core frame 30 is made of a plastic frame consisting of PBT and 20% glass fiber, and includes two thin portions consisting of an upper core frame and a lower core frame. The upper core frame 30 and the lower core frame 30 are coupled to each other and combined with the built-in component assembly 20 so as to enclose the waterproofing portion of the built-in component assembly 20. The core frame 30 is largely divided into a core frame installed on the outer surface of the body built-in component assembly 21 and another core frame installed on the outer surface of the flip built-in component assembly 25, which are separately defined as a body core frame and a flip core frame, respectively, but designated by the same reference numeral.

On the outer surface of the core frame 30 is formed a lattice-type flow channel 31 inwardly recessed to a predetermined depth, for the purpose of facilitating smooth flow of the resin during injection molding. Since the core frame 30 is thin, reinforcing ribs (not shown) for reinforcing the strength of the core frame 30 are prepared on some regions of the internal surface of the core frame 30.

The EVA sponge 50, which is a heat-insulating and shock-absorbing member, is installed between the core frame 30 and the built-in component assembly 20. The electromagnetic shielding sheet 60 is installed between the EVA sponge 50 and the core frame 30. The electromagnetic shielding sheet 60 for shielding electromagnetic interference (EMI) is made by coating a thin copper plate or a thin aluminum plate with a PVC sheet. In consideration of shape of the core frame 30 and arrangement of circuit components, moldings are used as the electromagnetic shielding sheet 60. The EVA sponge 50, which is a heat-insulating and shock-absorbing member, fills spaces between each of the circuit components mounted on the PCB 22, 28 and covers the circuit components. The core frame side surface of the EVA sponge 50 is flattened. The electromagnetic shielding sheet 60 is placed on the flattened surface. One of main purposes of installing the EVA sponge 50 is to provide a flattened surface for installation of the electromagnetic shielding sheet 60. The EVA sponge 50 also serves to protect various circuit components of the PCB 22, 28, such as ICs, chip resistors or chip condensers, from heat and pressure during injection molding.

The elastomer 40 as a resin molded article is arranged on the outer surface of the core frame 30 and is integrally injection-molded with the core frame 30 and the built-in component assembly 20. In this case, shock-absorbing protrusions 41 protruding outward from the outer surface of the core frame 30 are provided on some regions of the outer surface of the core frame 30, specifically eight corners of the core frame 30 and other necessary portions. The shock-absorbing protrusions 41 serve to protect built-in circuit components from external impacts. According to this embodiment, elastomer is used as a material of the resin molded article. This is because elastomer is fused well into a plastic surface, that is, the surface of the core frame 30, during injection molding, thereby maintaining high adhesiveness and airtightness.

A connection structure between each of the body built-in component assembly 21 , the core frame 30, and the elastomer 40 will now be described in detail with reference to FIG. 3. The EVA sponge 50 is installed on the opposite side of the keypad unit 23 of the body PCB in the body built-in component assembly 21 , and the electromagnetic shielding sheet 60 is installed in contact with the outer surface of the EVA sponge 50. The body core frame 30 is coupled to the body built-in component assembly 21 so as to enclose the waterproofing portion of the body built-in component assembly 21. The elastomer 40 as a resin molded article for plugging gaps formed in the body core frame 30 and spacing between the body core frame 30 and the keypad unit 23, is injection-molded on the outer surface of the body core frame 30. Since the surface of the keypad unit 23 is not necessarily injection-molded with the elastomer 40, the body core frame 30 is not installed thereon. During injection molding, the keypad unit 23 may be damaged due to a direct contact between the keypad unit 23 and an injection mold. Thus, in order to prevent the keypad unit 23 from directly contacting with the injection mold, a plastic case, that is, the protection member 39, is attached to the keypad unit 23 during injection molding, and is then removed after the injection molding is completed. In addition, at a portion designated by 'A', that is, at a portion where the external antenna 22c is installed, the elastomer 40 is bent inward so as to form a hole tightly contacting with the outer surface of the external antenna 22c and having a diameter slightly smaller than that of the external antenna 22c in the neighborhood of an outer edge of the external antenna 22c, thereby filling gaps through which water or moisture may infiltrate.

As shown in FIG .4, a connection structure between the core frame 30 and the elastomer 40 in the flip built-in component assembly 25, is similar to that in the body built-in component assembly 21. The EVA sponge 50 is installed on the rear surface of the PCB 28 of the LCD 26 of the flip built-in component assembly 25, and the electromagnetic shielding sheet 60 is installed on the outer surface of the EVA sponge 50.

The flip core frame 30 is installed so as to enclose the waterproofing portion of the flip built-in component assembly 25. The elastomer 40 as a resin molded article for plugging gaps formed in the flip core frame 30 and spacing between the flip core frame 30 and the LCD 26, is injection-molded on the outer surface of the flip core frame 30. The LCD 26 may be damaged if the LCD 26 directly contacts an injection mold during injection molding. Therefore, in order to prevent the LCD 26 from directly contacting with the injection mold, the protection member 39 consisting of a plastic case and a heat-dissipating shock-absorbing member, is attached to the surface of the LCD 28, followed by performing injection molding, and is then sequentially removed after the injection molding is completed. In this case, at a portion designated by 'B', that is, at a portion to which the flexible connector 29 is connected, the elastomer 40 is bent inward so as to form a hole having a diameter slightly smaller than that of the flexible connector 29, so that the elastomer 40 tightly contacts with the flexible connector 29, thereby filling gaps through which water or moisture may infiltrate.

FIG. 5 is a detailed diagram of the flexible connector 29 shown in FIG. 2, including a connector plug 29a and a flexible PCB 29b. The flexible connector 29 is formed by performing insertion molding of the elastomer 40 on the outer surface of the flexible PCB 29b rather than installing the core frame 30.

A waterproofing method of the above-described portable electronic product having a waterproof structure according to an embodiment of the present invention will now be described.

All circuit components are first inspected whether they operate normally or not after being assembled, providing the built-in component assembly 20. Next, the electromagnetic shielding sheet 60 is mounted inside the core frame 30, and the EVA sponge 50 is installed in contact with the outer surface of the electromagnetic shielding sheet 60. Then, the core frame 30 having the electromagnetic shielding sheet 60 and the EVA sponge 50, is installed so as to enclose the waterproofing portion of the built-in component assembly 20. Thereafter, a plastic case as the protection member 39, is attached to the surface of the keypad unit 23 in the body built-in component assembly 21 , while a plastic case and a heat-dissipating shock-absorbing member as the protection member 39, are attached to the surface of the LCD 26. Subsequently, the built-in component assembly 20 is inserted into a specially designed insertion mold and then the elastomer 40 is injection- molded, thereby perfectly sealing the waterproofing portion of the built-in component assembly 20. In this case, the elastomer 40 is formed at some portions, such as various connectors for connecting the respective components with external devices, the earphone jack 22b, or the external antenna 22a, like at the 'A' portion shown in FIG .3 or at the 'B' portion shown in FIG .4. During molding of the elastomer 40, if necessary, a mold is configured such that molding and separation of the elastomer 40 can be simultaneously performed by forming a cutting line (not shown) on the outer surface of the resin molded article. The thus-formed built-in component assembly 20 into which the elastomer 40 is integrally molded, has not only characteristic functions exerted by all circuit components but also a perfect waterproofing function. The waterproofing function can be performed by preventing circuit components of the PCB 22, 28 from contacting with water or moisture. Then, the built-in component assembly 20 is accommodated in and combined with the casing 10, thereby completing an assembling work of the mobile phone 1.

FIG. 6 is a plan view of a built-in component assembly of a mobile phone according to another embodiment of the present invention, FIG. 7 is a right side view of a body built-in component assembly shown in FIG. 6, and FIG. 8 is a right side view of a flip built-in component assembly shown in FIG. 6. The same reference numbers as those in the foregoing embodiment are used to denote the same elements, and numbers obtained by adding 100 to the reference numbers used to denote the elements of the foregoing embodiment are used to denote modified elements thereof. Unlike in the foregoing embodiment in which the resin molded article (elastomer) 40 is injection-molded to a predetermined thickness using the built-in component assembly 20 to which the core frame 30 is coupled, as an insert, according to the present embodiment as shown in the drawings, an upper resin molded article 140 and a lower resin molded article 140 are vacuum-molded separately so as to have an internal shape corresponding to an external shape of the built-in component assembly 120 combined with the upper core frame 130 and the lower core frame 130. Then, each resin molded article 140 is combined with each core frame 130 by ultrasonic fusion, and the upper and lower core frames 130 with which the upper and lower resin molded articles 140 are combined by ultrasonic fusion, are coupled to each other so as to accommodate the built-in component assembly 120 therein, followed by further forming a rubber printing layer 170 on the outer surface of the resin molded article 140. According to this embodiment, the casing 10 and the built-in component assembly that is not subjected to waterproofing treatment are the same as those of the foregoing embodiment, and an explanation thereof will not given. Only elements different from those of the foregoing embodiment will now be described.

According to the present embodiment, a core frame 130 includes an upper core frame and a lower core frame, both being designated by the same reference number 130, which are coupled to and face each other, like in the foregoing embodiment. In the peripheral portion of the upper core frame 130, an engagement protrusion 131 is formed along the periphery of the peripheral portion. In the peripheral portion of the lower core frame 130, an engagement groove 132 corresponding to the engagement protrusion 131 of the upper core frame 130 is formed. When the upper core frame 130 and the lower core frame 130 are coupled to each other, the engagement protrusion 131 and the engagement groove 132 are engaged to each other, thereby establishing a tight connection between the upper core frame 130 and the lower core frame 130 without any clearance therebetween. Also, each of the upper and lower core frames 130 has at its distal end a sloping portion 133 whose external side is inclined such that the thickness thereof is thinner outward. When the upper core frame 130 and the lower core frame 130 are coupled to each other, a wedge-shaped groove 134 is formed on a surface where they face each other, that is, on a coupling surface. In an event of malfunctioning, the overall built-in component assembly 120 is generally replaced. In a case where a repairing work can be effected by removing only the resin molded article 40, however, the wedge-shaped groove 134 can be easily detached from the built-in component assembly 120 by cutting away only the resin molded article 140 along the groove 134. A plurality of protrusions 135 for ultrasonic fusion are formed on the outer surfaces of the upper and lower core frames 130, thereby facilitating ultrasonic fusion with the resin molded article 140.

The resin molded article 140 according to the present embodiment is shaped in a desired manner by vacuum molding, separately from the core frame 130.

FIG. 9 is a plan view of an upper resin molded article combined with the flip built-in component assembly, FIG. 10 is a left side view of FIG. 9, FIG. 11 is a plan view of a lower resin molded article combined with the flip built-in component assembly, and FIG. 12 is a left side view of FIG. 11. In a similar manner in which the upper and lower resin molded articles 140a and 140b of the flip built-in component assembly 125 are formed as shown in the drawings, the upper and lower resin molded articles 140 of the body built-in component assembly 121 are also shaped in a desired manner. That is, the resin molded article 140 is molded so as to have an internal shape corresponding to an external shape of the built-in component assembly 120 having the core frame 130 combined therewith.

Vacuum molding, which is a kind of plastic molding processing methods, is performed such that an edge of a plastic plate is compressed on a lower mold with a clamp, an upper portion of the plastic plate is heated and air is then exhausted from the mold when the plastic plate is sufficiently softened. In the present embodiment, a transparent synthetic resin plate, such as polyester, polycarbonate or an acrylonitrile butadiene styrene (ABS) copolymer resin, is installed on a mold for vacuum molding, and heating, vacuum molding and cutting are sequentially performed, thereby finally manufacturing a resin molded article having a desired shape, as shown in FIGS. 9 through 12. According to the present embodiment, unlike in the foregoing embodiment, the resin molded article 140, generally transparent, may be shaped such that it can cover a surface of an LCD without cutting a display portion facing the surface of the LCD. The resin molded article 140 manufactured for connection with the core frame 130 coupled to a side of a keypad unit 123 of the body built-in component assembly 121 , may be integrally molded with the keypad unit 123 if the keypad unit 123 is injection-molded using the manufactured resin mold article 140 as an insert.

The molten upper and lower resin molded article 140 are combined with the corresponding upper and lower core frames 130 by ultrasonic fusion, respectively, and the upper and lower core frames 130 having the respective resin molded articles 140 combined therewith by ultrasonic fusion, are coupled to each other so as to accommodate the built-in component assembly 120 therein. When the coupling is completed, gaps formed at the coupled portion are sealed by engagement between the engagement protrusion 131 of the upper core frame 130 and the engagement groove 132 of the lower core frame 130.

Also, the resin molded articles 140 are formed on the outer surfaces of the upper and lower core frames 130 in a close contact type. Therefore, a waterproof structure can be primarily attained. The rubber-painted layer 170 is formed on the outer surface of the resin molded article 140. The rubber-painted layer 170, which is a paint for spraying and is composed of rubber, has a surface strength strong enough to be used for interior construction, although the surface strength thereof is slightly poor compared to the elastomer described in the foregoing embodiment, and has good workability and adhesiveness, exhibiting excellent waterproofing capability. That is, the primary waterproof structure attained by the resin molded article 140 can be secondarily enhanced by the rubber-painted layer 170, thereby achieving waterproofing in a more secured manner. A waterproofing method of the above-described portable electronic product having a waterproof structure according to another embodiment of the present invention will now be described.

All circuit components are first inspected whether they operate normally or not after being assembled, providing the built-in component assembly 120. Next, the upper core frame 130 and the lower core frame 130 each having a shape corresponding to that of the built-in component assembly 120, are provided by injection molding.

Then, the upper resin molded article 140 and the lower resin molded article 140 having internal shapes corresponding to external shapes of the upper core frame 130 and the lower core frame 130 are provided by vacuum molding. Generally, a transparent synthetic resin plate, such as polyester, polycarbonate or an ABS copolymer resin, is installed on a mold for vacuum molding, and processing, vacuum molding and cutting are performed, thereby finally manufacturing the resin molded article having a desired shape. Here, as described above, the upper resin molded article 140 connected with the upper core frame 130 of the body built-in component assembly 121 , may be integrally molded with the keypad unit 123 if the keypad unit 123 is injection-molded using the manufactured resin molded article 140 as an insert.

Next, the upper core frame 130 and the lower core frame 130 are arranged inside the upper resin molded article 140 and the lower resin molded article 140, respectively, and then are combined therewith by ultrasonic fusion.

The upper core frame 130 and the lower core frame 130 are coupled to each other so as to accommodate the built-in component assembly 120 in the core frame 130 having the resin molded article 140 combined therewith by ultrasonic fusion. In the peripheral portions of the upper and lower core frames 130, an engagement protrusion 131 and an engagement groove 132 are formed along the peripheries of the peripheral portions. When the engagement protrusion 131 and the engagement groove 132 are engaged to each other, a tight connection between the upper core frame 130 and the lower core frame 130 is established, thereby primarily attaining a waterproof structure.

Thereafter, rubber painting is performed on the outer surface of the resin molded article 140. To this end, the built-in component assembly 120 having the core frame 130 and the resin molded article 140 combined with each other, is first installed in an automatic jig, and painting is performed on the outer surface of the resin molded article 140 by a spraying method to form the rubber-painted layer 170, followed by drying and performing a waterproofing pressure test. The thus-completed built-in component assembly 120 has not only characteristic functions exerted by all circuit components but also a perfect waterproofing function. The waterproofing function can be performed by preventing the circuit components of a PCB from contacting with water or moisture. Then, the built-in component assembly 120 is accommodated in and combined with the casing 10, thereby completing an assembling work of the mobile phone 1. As described above, according to the present invention, the resin molded article 40 is injection-molded with a material, e.g., elastomer, using the built-in component assembly 20 combined with the core frame 30, as an insert, or a separately provided material, e.g., polycarbonate, by vacuum molding. Then, the waterproofing portions 20, 120 accommodated in the casing 10, are enclosed by the resin molded article 140 combined with the core frame 30, 130. In such a manner, ensured waterproofing capability, by which water or moisture can be prevented from infiltrating into built-in circuit components of the built-in component assembly 20, 120 even after being exposed to water, can be achieved without a considerable increase in manufacturing cost nor an adverse effect on designing of the casing 10.

Although folder type mobile phones have been described throughout the above-described embodiments, the waterproof structure according to the present invention can be applied to any type of portable electronic products including a flip type mobile phone, that have a built-in component assembly while having a casing and a waterproofing portion, the built-in components being accommodated in and combined with the casing. Also, the present invention can be applied to various portable electronic products, such as a PDA, a notebook type computer, an LCD TV, a portable wireless apparatus, a CD player, an MP3 player and so on, by combining a core frame with a built-in component assembly and forming a resin molded article contacting with and coupled to the core frame outside the core frame, thereby achieving ensured waterproofing capability function.

While the present invention has been described in connection with a case where elastomer is used as a material of a resin molded article injection-molded using a built-in component assembly combined with the core frame as an insert, any kind of resin materials that are fused well to a surface of a core frame during injection molding so as to maintain high adhesiveness and airtightness, can also be employed.

Further, in the above-described embodiment in which a resin molded article is separately formed to be combined with a core frame, the present invention has been described in connection with a case where vacuum molding is employed. However, blow molding may also be used as long as a resin molded article having a desired shape can be formed. Also, although it has been described in the illustrative embodiment that a separately resin molded article is combined with the core frame by ultrasonic fusion, an adhesive agent may be used in combining the resin molded article with the core frame. Although it has been described in the above-described embodiments that an EVA sponge is used as a heat-insulating and shock-absorbing member, other kinds of materials, such as a non-woven fabric, may also be used as long as they are capable of insulating heat and absorbing external shocks. Also, while it has been described in the above-described embodiment that a heat-insulating and shock-absorbing member and an electromagnetic shielding sheet are separately provided, a single substance serving as the heat-insulating and shock-absorbing member and the electromagnetic shielding sheet, can be used, if available.

Industrial Applicability

As described above, according to the present invention, there are provided a portable electronic product having ensured waterproofing capability, and a waterproofing method thereof, the ensured waterproofing capability by which water or moisture can be prevented from infiltrating into built-in circuit components even after being exposed to water, without a considerable increase in manufacturing cost nor an adverse effect on designing of a casing.

Claims

What is claimed is:

1. A portable electronic product having a waterproof structure having a casing defining an accommodating space inside, and a built-in component assembly having a waterproofing portion to be avoided from contacting with water or moisture, and accommodated in and combined with the casing, the portable electronic product comprising: a core frame combined with the built-in component assembly along the outer periphery of the built-in component assembly so as to enclose the waterproofing portion of the built-in component assembly; and a resin molded article contacting and connected with the core frame on the outer surface of the core frame so as to prevent external water or moisture from infiltrating into the waterproofing portion.

2. The portable electronic product of claim 1 , wherein the resin molded article is injection-molded to a predetermined thickness using the built-in component assembly to which the core frame is coupled, as an insert, and is combined with the core frame during injection molding.

3. The portable electronic product of claim 2, further comprising: a heat-insulating and shock-absorbing member installed between the core frame and the built-in component assembly, for insulating heat and absorbing shocks from the built-in component assembly; and an electromagnetic shielding sheet installed between the heat-insulating and shock-absorbing member and the core frame, for shielding electromagnetic interference.

4. The portable electronic product of claim 3, wherein the heat-insulating and shock-absorbing member is an ethylene vinyl acetate (EVA) sponge.

5. The portable electronic product of claim 2, wherein the resin molded article is an elastomer mold.

6. The portable electronic product of claim 2, wherein shock-absorbing protrusions protruding outward from the outer surface of the resin molded article are provided on some regions of the outer surface of the resin molded article, a cutting line for cutting the resin molded article is prepared on the outer surface of the resin molded article, a flow channel inwardly recessed to a predetermined depth is formed on the outer surface of the core frame for the purpose of facilitating smooth flow of the resin during injection molding, and reinforcing ribs for reinforcing the strength of the core frame are prepared on some regions of the internal surface of the core frame.

7. The portable electronic product of claim 1 , wherein the resin molded article is vacuum-molded so as to have an internal shape corresponding to an external shape of the built-in component assembly and is then combined with the core frame.

8. The portable electronic product of claim 7, wherein the resin molded article is combined with the core frame by ultrasonic fusion.

9. The portable electronic product of claim 7, further comprising a rubber-painted layer coated on at least some regions of the outer surface of the resin molded article.

10. The portable electronic product of claim 7, wherein the core frame comprises an upper core frame and a lower core frame facing and coupled to each other, the resin molded article comprises an upper resin molded article and a lower resin molded article which are combined with the upper core frame and the lower core frame by ultrasonic fusion, respectively, an engagement protrusion is formed along the periphery of the peripheral portion of one of the upper and lower core frames, and an engagement groove corresponding to the engagement protrusion is formed along the periphery of the peripheral portion of the other of the upper and lower core frames of the lower core frame.

11. The portable electronic product of claim 7, wherein at least one of the upper and lower core frames has at its distal end a sloping portion whose external side is inclined such that the thickness thereof is thinner outward.

12. A waterproofing method of a portable electronic product having a casing defining an accommodating space inside, and a built-in component assembly having a waterproofing portion to be avoided from contacting with water or moisture, and accommodated in and combined with the casing, the waterproofing method comprising: combining a core frame with the built-in component assembly along the outer periphery of the built-in component assembly so as to enclose the waterproofing portion of the built-in component assembly; and performing injection molding of a resin molded article to a predetermined thickness on the outer surface of the core frame and at least some regions of the outer surface of the built-in component assembly using the built-in component assembly combined with the core frame as an insert to prevent water or moisture from infiltrating into the waterproofing portion of the built-in component assembly.

13. The waterproofing method of claim 12, wherein the built-in component assembly further comprises a protection portion to be avoided from contacting with an injection mold during injection molding, and the waterproofing method further comprises installing a protection member configured to contact with the injection mold during injection molding, on the protection portion of the built-in component assembly before the resin molded article is integrally injection-molded with the core frame and the built-in component assembly, and removing the protection member after the injection molding is completed.

14. The waterproofing method of claim 12 or 13, wherein the combining of the core frame with the built-in component assembly is preceded by installing an electromagnetic shielding sheet in the core frame so as to prevent electromagnetic interference, and installing a heat-insulating and shock-absorbing member on the core frame so as to contact with the outer surface of the electromagnetic shielding sheet.

15. A waterproofing method of a portable electronic product having a casing defining an accommodating space inside, and a built-in component assembly having a waterproofing portion to be avoided from contacting with water or moisture, and accommodated in and combined with the casing, the waterproofing method comprising: preparing a core frame combined with the built-in component assembly along the outer periphery of the built-in component assembly so as to enclose the waterproofing portion of the built-in component assembly; preparing a resin molded article having an internal shape corresponding to an external shape of the core frame to a predetermined thickness by vacuum molding; combining the resin molded article with the core frame; and combining the built-in component assembly with the core frame combined with the resin molded article.

16. The waterproofing method of claim 15, further comprising forming a rubber-painted layer on at least some regions of the outer surface of the resin molded article after the combining of the built-in component assembly with the core frame.

17. The waterproofing method of claim 15, wherein the resin mode is made of a transparent polyester resin and is combined with the core frame by ultrasonic fusion.

18. The waterproofing method of claim 17, wherein the core frame comprises an upper core frame and a lower core frame facing each other, the resin molded article comprises an upper resin molded article and a lower resin molded article which are combined with the upper core frame and the lower core frame by ultrasonic fusion, respectively, an engagement protrusion is formed along the periphery of the peripheral portion of one of the upper and lower core frames, and an engagement groove corresponding to the engagement protrusion is formed along the periphery of the peripheral portion of the other of the upper and lower core frames of the lower core frame.