JP2002151931A - Built-in antenna for mobile phone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a built-in antenna for mobile phones, which can easily be mass-produced, realize a desired shape of a curved face and attain high reliability in the electric connection to a printed circuit board. SOLUTION: The built-in antenna for mobile phones is characterized in that resin onto which metallic plating is hardly formed (hardly platable resin) and resin onto which metallic plating is easily formed (easily platable resin) are injection molded in two stages to obtain a composite mold, the composite mold has a radiation element part formed by the easily platable resin and a contact part that electrically interconnects the radiation element part and other conductive members in the mobile phone, and a conductive metallic layer is formed on the surface of the radiation element part and the contact part by electroless plating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a built-in antenna for a mobile phone manufactured by injection molding, and more particularly to an antenna for a mobile phone capable of achieving highly reliable electrical connection with a printed circuit board or the like. .

[0002]

2. Description of the Related Art Conventionally, as a built-in antenna for a portable telephone, an antenna having a structure in which an antenna plate obtained by punching a copper plate into a predetermined shape is bonded to a plastic molded product has been generally employed. While the mobile phone market is increasing, adopting an antenna plate by punching a copper plate requires a process such as bending to fix the antenna plate to a plastic molded product, which poses a problem in terms of manufacturing efficiency. is there. In addition, the degree of freedom in design and three-dimensional design required for mobile phones is limited, and it takes time to match the connection contacts in electrical connection with other wiring in the mobile phone. There's a problem.

In order to solve the problems of a portable built-in antenna employing a copper plate punched antenna plate,
A structure as shown in FIG. 4 (explanatory view in section) and FIG. 5 (explanatory view in plan) has been proposed. Reference numeral 10 denotes a composite molded product, a resin on which metal plating is difficult to be formed (resin-resistant resin).
And a second molded product 12 obtained by injection-molding a resin (easy plating resin) on which metal plating is easily formed, and a through hole 13 is provided. By subjecting the composite molded article 10 to electroless plating, the surface of the second molded article 12 and the through hole 1 are formed.
3 are formed with conductive metal layers 14 and 15, respectively. The conductive metal layer 14 functions as a radiating element, and the radiating element is electrically connected to a printed board 16 via the conductive metal layer 15.

[0004]

Such an antenna formed by two-stage injection molding is excellent in manufacturing efficiency and can easily realize a three-dimensional shape such as a curved surface type, but the entire antenna is formed of a plastic molded product. Therefore, there is a concern about the reliability of the electrical connection with the printed circuit board via the through-holes due to long-term use.

SUMMARY OF THE INVENTION An object of the present invention is to provide a built-in antenna for a portable telephone which can be easily mass-produced, can realize a desired curved shape, and can achieve high reliability in electrical connection to a printed circuit board. Is what you do.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a resin that is difficult to form metal plating (resin-hard resin) and a resin that is easy to form metal plating (easy-to-plate resin). A step injection molding is performed to obtain a composite molded product, and the composite molded product is a radiating element portion molded with an easily-plated resin, and a contact for electrically connecting the radiating element portion to another conductive member in the mobile phone. The present invention provides a built-in antenna for a mobile phone, comprising a conductive metal layer formed by electroless plating on the surfaces of the radiating element portion and the contact portion.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, examples of difficult-to-plate resins include resins selected from liquid crystal polyester, polyphenylene sulfide, polyetheretherketone, polyetherimide, polysulfone, polyethersulfone, and syndioctatic polystyrene. .
For use in a built-in antenna for a mobile phone, syndioctatic polystyrene, which has a low dielectric constant, a low dielectric loss tangent, excellent mechanical properties, and is lightweight, is most suitable.

[0008] Examples of the easily-platable resin include those obtained by filling a resin similar to the above-mentioned hard-to-plate resin with a catalyst for electroless plating. Representative examples of electroless plating catalysts include:
One obtained by adsorbing palladium on powdered aluminum silicate can be used.

When a composite molded product is obtained by two-stage injection molding, either the hard-to-plate resin or the easily-plated resin may be used as the primary molded product. However, the primary molded product is held on a mold and The molding resin is injection molded.

In the present invention, from the viewpoint of long-term stability of electrical contact, it is preferable that the contact portion has a high elasticity and a high spring property. If glass fiber as a reinforcing material is included in the resin, the elasticity is reduced. Therefore, the easily-platable resin is preferably a resin containing no glass fiber. Examples of resins that can achieve sufficient mechanical strength without containing glass fibers include syndiotactic polystyrene, liquid crystal polyester, and polyether sulfone.

An embodiment of the present invention will be described with reference to FIGS. 1 is an explanatory perspective view seen from above, FIG. 2 is an explanatory perspective view seen from below, and FIG. 3 is an explanatory sectional view taken along line AB in FIG. Reference numeral 1 denotes a composite molded product, which is composed of a first molded product 2 obtained by injection-molding a hard-to-plate resin, and a second molded product 3 obtained by injection-molding an easily-plateable resin. The second molded article 3 has a radiating element part 4 and a contact part 5, a conductive metal layer 6 is formed on the surface of the radiating element part 4 by electroless plating, and a non-conductive metal layer 6 is formed on the surface of the contact part 5. The conductive metal layer 7 is formed by electrolytic plating. The conductive metal layer 7 has a bent portion 8 formed at the tip to ensure surface contact with the printed circuit board P. Reference numeral 9 denotes a frame formed by the primary molded product 2, which is provided on the periphery of the radiating element portion 9 to maintain the mechanical strength of the entire antenna. The contact portion 5 is formed in a cutout portion of the frame 9 in parallel with the frame 9.

As described above, the conductive metal layer 6 serving as the radiating element of the antenna is electrically connected to the printed circuit board P via the conductive metal layer 7 of the contact portion 5, thereby providing a stable electrical connection for a long period of time. Contact is achieved.

[0013]

As described above, according to the present invention, a built-in portable telephone which can be easily mass-produced, can realize a desired curved surface shape, and can achieve high reliability in electrical connection to a printed circuit board. An antenna is realized.

[Brief description of the drawings]

FIG. 1 is a perspective explanatory view of an embodiment of a built-in antenna for a mobile phone according to the present invention as viewed from above.

FIG. 2 is an explanatory perspective view seen from below of the embodiment of the mobile phone built-in antenna of the present invention.

FIG. 3 is an explanatory sectional view taken along line AB in FIG. 1;

FIG. 4 is a sectional explanatory view of a conventional built-in antenna for a mobile phone.

FIG. 5 is an explanatory plan view of a conventional built-in antenna for a mobile phone.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 composite molded product 2 first molded product 3 second molded product 4 radiating element portion 5 contact portion 6, 7 conductive metal layer 8 bent portion 9 frame P printed circuit board

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shinichiro Suzuki 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture F-term in the Hidaka Plant of Hitachi Cable, Ltd. (reference) 5J046 AA05 AA09 AA19 AB13 PA07 5J047 AA05 AA09 AA19 AB13 FD01

Claims (5)

[Claims] 1. A composite molded product is obtained by two-stage injection molding of a resin on which metal plating is not easily formed (hard-plating resin) and a resin on which metal plating is easily formed (easy-plating resin). Has a radiating element portion molded with an easily-plated resin, and a contact portion for electrically connecting the radiating element portion to another conductive member in the mobile phone. A built-in antenna for a mobile phone, wherein a conductive metal layer is formed on the surface by electroless plating. 2. The built-in cell phone according to claim 1, wherein the molded product made of the easily-plated resin forming the contact portion is integrally formed with the molded product made of the easily-plated resin forming the metal pattern. antenna. 3. The built-in antenna for a mobile phone according to claim 1, wherein said hard-to-plate resin and said easy-to-plate resin are both compositions mainly composed of syndioctatic polystyrene. 4. The built-in antenna for a mobile phone according to claim 1, wherein said easily-platable resin is a composition containing no glass fiber. 5. The built-in antenna for a cellular phone according to claim 1, wherein said composite molded article has a frame formed of said hard-to-plate resin, and said contact portion is formed in a cutout portion of said frame.