JP2002111368A - Built-in antenna for mobile phone - Google Patents

Abstract

(57) [Summary] (with correction) [Problem] To provide a built-in antenna for a mobile phone 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. A resin that is difficult to form metal plating (hard-to-plate resin) and a resin that easily forms metal plating (easy-to-plate resin) are subjected to two-stage injection molding to obtain at least a molded article made of easy-to-plate resin. A composite molded article M partially exposed on the surface is obtained, and a conductive metal layer 5 is formed on the surface of the molded article made of the easily-platable resin of the composite molded article M by electroless plating. A built-in antenna for a mobile phone, wherein the antenna is configured to be electrically connected to another conductive member in the mobile phone via a metal piece 7 embedded in the article M.

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. 3 (explanatory view in section) and FIG. 4 (explanatory view in plan) has been proposed. Reference numeral 10 denotes a composite molded product, which is a resin on which metal plating is not easily 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 product 10 to electroless plating, the surface of the second molded product 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 is electrically connected to the 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 to the printed circuit board 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 provides two types of resins, one in which metal plating is difficult to form (hard plating resin) and the other in which metal plating is easy to form (easy plating resin). Step injection molding is performed to obtain a composite molded product in which at least a part of the molded product made of the easily-platable resin is exposed on the surface, and the surface of the composite molded product made of the easily-plated resin is electrically conductive by electroless plating. A built-in antenna for a mobile phone, wherein a metal layer is formed, and the conductive metal layer is configured to be electrically connected to another conductive member in the mobile phone via a metal piece embedded in the composite molded article. I do.

[0007]

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

Examples of the easily plating resin include those obtained by filling a resin similar to the above-mentioned difficult-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.

In the case of obtaining a composite molded product by two-stage injection molding, either the difficult-to-plate resin or the easily-plateable resin may be used as the primary molded product, but the primary molded product is held on a mold and The molding resin is injection molded.

The metal piece electrically connects a conductive metal layer formed by electroless plating on the surface of an easily-plated resin and a printed wiring for grounding, and is made of copper or copper alloy excellent in electric conductivity. It preferably comprises The metal piece may be embedded at the time of injection molding of the composite molded product, or a through hole may be formed in the composite molded product and fitted into the through hole. The metal piece may be fitted into the through hole before or after the electroless plating. In order to ensure the holding of the metal pieces, it is desirable to use a copper plate rich in spring properties, and projections or bends may be provided as necessary.

FIG. 1 is a sectional explanatory view of one embodiment of the present invention, wherein M is a composite molded product, in which a first molded product 1 obtained by injection-molding a difficult-to-plate resin and an injection-moldable resin that is easily plated. The second molded product 2 is made as follows. 3 is a through hole, 4 is a conductive metal layer formed by electroless copper plating on the surface of the second molded article 2, 5 is a conductive metal layer formed by electroless copper plating on the peripheral surface of the through hole 3, 6 Is a printed circuit board,
Reference numeral 7 denotes a copper piece fitted into the through hole 3. Copper piece 7
Is inserted into the through-hole 3 after the electroless plating, and the copper piece 7 is in close contact with and electrically connected to the conductive metal layer 5 formed on the peripheral surface of the through-hole 3. By bending the lower end, surface contact with the printed circuit board 6 is ensured.

As described above, since the conductive metal layer 4 serving as the radiating element of the antenna is electrically connected to the printed circuit board 6 via the copper piece 7, stable electrical contact is achieved over a long period of time. .

FIG. 2 is an explanatory sectional view of another embodiment of the present invention. The same reference numerals as in FIG. 1 denote the same parts.
In this embodiment, the copper piece 27 is embedded in the through hole 3 and then subjected to electroless plating. The conductive metal layers 28 and 29 are also formed on the exposed surface of the copper piece 27 by electroless plating. In particular, by forming the conductive metal layer 28,
Good electrical connection between the conductive metal layer 4 and the copper piece 27 is achieved, and stable electrical contact is ensured.

[0014]

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 an explanatory cross-sectional view of an embodiment of a built-in antenna for a mobile phone according to the present invention.

FIG. 2 is an explanatory cross-sectional view of another embodiment of the built-in antenna for a mobile phone of the present invention.

FIG. 3 is an explanatory sectional view of a conventional built-in antenna for a mobile phone.

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

[Explanation of symbols]

 M Composite molded article 1 First molded article 2 Second molded article 3 Through hole 4 Conductive metal layer 5 Conductive metal layer 6 Printed circuit board 7 Metal piece

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinichiro Suzuki 5-1-1 Hidaka-cho, Hitachi City, Ibaraki Prefecture F-term in the Hidaka Factory, Hitachi Cable, Ltd. 4F206 AA13 AH33 JA07 JB21 JW31 JW50 5J045 AB06 BA01 DA10 EA07 LA01 LA03 LA04 MA01

Claims (6)

[Claims] 1. A two-stage injection molding of a resin in which metal plating is not easily formed (hard-to-plate resin) and a resin in which metal plating is easily formed (easy-plated resin) to obtain a molded article made of easily-plated resin. Obtaining a composite molded product at least partially exposed on the surface, forming a conductive metal layer on the surface of a molded product made of an easily-plated resin of the composite molded product by electroless plating, wherein the conductive metal layer is formed of the composite molded product. A built-in antenna for a mobile phone, which is configured to be electrically connected to another conductive member in the mobile phone via a metal piece embedded in the product. 2. The built-in antenna for a mobile phone according to claim 1, wherein said metal piece is fitted into a through hole formed in a composite molded product. 3. The built-in antenna for a mobile phone according to claim 2, wherein said metal piece is fitted into a through hole after electroless plating. 4. The built-in antenna for a cellular phone according to claim 2, wherein said metal piece is fitted into a through hole before electroless plating. 5. The built-in antenna for a mobile phone according to claim 1, wherein said metal piece is embedded in said composite molded article during two-stage molding. 6. 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 syndiotactic polystyrene.