This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2007-184385, filed on Jul. 13, 2007; the entire contents of which are incorporated herein by reference.
1. Field of the Invention
This invention relates to an electronic device and a method for manufacturing the same.
2. Background Art
There is a strong demand for downsizing electronic devices such as mobile phones and PDAs (personal digital assistants). Improvement of the enclosure structure is needed for the downsizing while reducing the influence of noise from the integrated circuit and high-frequency circuit exerted on the antenna.
In this case, a structure can be contemplated in which the antenna is placed on the enclosure side, away from the substrate populated with the integrated circuit and high-frequency circuit. Placing the antenna on the outer surface side of the enclosure constrains the design, and may also change the antenna characteristics when a human body comes close thereto. Hence, more preferably, the antenna is placed on the inner surface side of the enclosure.
However, the inner surface side of the enclosure is often provided with a rib structure to ensure adequate stiffness, and also often provided with bosses for placing components. Placing the antenna pattern on the inner surface side of the enclosure provided with ribs and bosses constrains the shape.
JP-A 11-187096(Kokai) (1999) discloses a linear antenna placed like a loop around the liquid crystal display window of a mobile phone to save space for installing the antenna.
According to an aspect of the invention, there is provided an electronic device including: a first molded body having a recessed cross section and made of resin; a second molded body having a recessed cross section and made of resin, the second molded body being fitted inside the first molded body; and an antenna pattern sandwiched between the first and second molded body, among the surfaces of the first molded body, the surface on the side not adjacent to the antenna pattern constituting an outer surface.
According to another aspect of the invention, there is provided a method for manufacturing an electronic device, including: forming a first molded body having a recessed cross section and made of resin; inserting an antenna pattern inside the first molded body; forming a second molded body having a recessed cross section and made of resin; and fitting the second molded body inside the first molded body configured to sandwich the antenna pattern.
According to still an aspect of the invention, there is provided a method for manufacturing an electronic device, including: forming an antenna pattern on a surface of a second molded body made of resin by one of printing, plating, conductive material coating, and evaporation; and forming a first molded body having a recessed cross section and made of resin outside the second molded body configured to sandwich the antenna pattern, the second molded body being shaped to have a recessed cross section.
An embodiment of the invention will now be described with reference to the drawings.
The outer enclosure 52 is provided outside as viewed from the user in normal use. On the other hand, the inner enclosure 54 is provided inside as viewed from the user, that is, on the user's side, in normal use. The inner enclosure 54 is populated with at least one of an image display section such as a liquid crystal display 55 and a manipulation section.
The lower enclosure 60 includes an outer enclosure 62 and an inner enclosure 64. To the outer enclosure 62, a substrate populated with a high-frequency circuit including a power feeder unit, a signal processing circuit, a control circuit, and a power supply circuit, and a secondary battery are fixed. The inner enclosure 64 is populated with a keyboard and the like.
The antenna pattern layer 26 is sandwiched between the first molded body 10 and a second molded body 30, constituting a three-layer structure integrated with the enclosure. The first and second enclosure 10, 30 are formed by molding using a resin material, for example. The outer enclosure 52 can be formed in this manner.
According to this embodiment, an antenna pattern can be placed in a wide area on the inner surface of the outer enclosure 52. While two antenna patterns 20a, 20b are shown in
The antenna pattern layer 26 is inserted into the first molded body 10, which has a recessed cross section and is made of resin (S104). Here, the antenna pattern protection film 21 can be the above-mentioned film, or can be additionally provided. Likewise, the insulating film 22 can be the above-mentioned film, or a resin sheet having a thickness of several micrometers. The insertion of the antenna pattern layer 26 is followed by forming a second molded body 30, which is made of resin and has a recessed cross section (S106). Thus, an enclosure integrated antenna is completed. Here, alternatively, the second molded body 30 can be formed beforehand and fitted into the first molded body 10, and then they can be bonded or welded.
In
The power supply unit 40 including the substrate or the liquid crystal display section is connected to the antenna pattern through the feed point 42 (S110).
The antenna pattern layer 26 can be a thin stamped sheet metal.
A conductive paste 43 made of resin or the like is applied to the opening 31 to be connected to the feed point 42 (S204). Subsequently, a first molded body 10 is formed (S206), and the antenna pattern 20 is connected to the feed point 42 (S208).
Subsequently, the sheet is folded so that the antenna pattern 20 can be bonded to the first molded body 10 (S304), and the first molded body 10 is formed to cover the sheet (S306). The power supply unit 40 including the substrate or the liquid crystal display section is connected to the feed point 42 in this folded portion (S308).
In the electronic device based on the enclosure integrated antenna of the above first to fourth example, a wide area on the inner surface of the enclosure can be used for an antenna pattern region. Hence, the electronic device can be downsized while being equipped with antennas having different characteristics.
Furthermore, integration with the enclosure allows the antenna to be distanced from the substrate, and the influence of noise from the electronic components on the substrate can be reduced. Moreover, if the molded body on the substrate side is provided with a shielding effect, noise can be further reduced. Furthermore, this embodiment can prevent the antenna pattern from being disturbed by hands, and can avoid changing antenna characteristics such as directional characteristics.
Here, a description is given of the antenna pattern 20.
Antennas selected from the group including the antenna patterns 20 illustrated in
The embodiment of the invention has been described with reference to the drawings. However, the invention is not limited thereto. The material, shape, size, and placement of the antenna pattern, molded body, substrate, insulating film, and enclosure constituting the electronic device can be variously modified by those skilled in the art without departing from the spirit of the invention, and such modifications are also encompassed within the scope of the invention.
Number | Date | Country | Kind |
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2007-184385 | Jul 2007 | JP | national |