JPH057783Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to an antenna built into a small wireless device such as a radio paging receiver, and in particular, the antenna is provided with a surface finish that is easily oxidized such as silver plating, The present invention also relates to a built-in antenna of a small wireless device that is installed close to a printed board inside the device.

[Prior Art] FIG. 4 is an exploded perspective view showing a general antenna mounting structure of a radio paging receiver. As shown in the figure, the radio paging receiver has circuit components mounted on a printed board 1, an antenna 4 as well as a battery case 2, ROM 3, etc., installed on the printed board 1, and a case 5 and a top cover. The structure accommodates 6. Here, the antenna 4 is
Generally, both ends are connected and fixed to the printed board 1 by soldering or the like, and the middle part is formed into a loop shape to form a so-called loop antenna.

FIGS. 5 and 6 show conventional antennas of this type. As shown in these drawings, in the conventional antenna, an antenna substrate 41 made of a brass plate, a phosphor bronze plate, etc. is formed into a predetermined loop shape, and the entire surface is silver-plated for the purpose of improving electrical characteristics. A layer 42 was provided.

This silver-plated layer 42 is easily oxidized, and is particularly susceptible to darkening and deterioration in appearance during the manufacturing process and use due to sulfurization. Therefore, conventionally, in order to prevent deterioration of the appearance, an insulating layer 43 was formed on the external surface by spray painting.

Furthermore, as described above, since the antenna 4 is mounted close to the printed board 1, there is a risk of short-circuiting with electrical component leads, chip component mounting solders, etc. on the printed board 1. Therefore, conventionally, antenna 4
An insulator 7 made of polyester film was attached to the inner surface of the case using double-sided tape.

[Problems to be solved by the invention] In the conventional antenna described above, the rust prevention treatment of the silver plating layer 42 was applied only to the outer surface.
Electrical characteristics sometimes deteriorated due to oxidation of the inner surface.

Further, since the insulator 7 was pasted to provide insulation, the cost of the insulator 7 was high, and the manufacturing lead time was lengthened by the pasting work.

Furthermore, since the insulating layer 43 on the surface was formed by spray painting, it could not be coated to a uniform thickness, resulting in variations in accuracy.

The present invention was developed in consideration of the above-mentioned problems, and is a compact design that maintains excellent appearance and electrical characteristics over a long period of time, and also eliminates the need for an insulator, reducing costs and manufacturing time. The purpose is to provide built-in antennas for wireless devices.

[Means for Solving the Problems] In order to achieve the above object, the built-in antenna of the small wireless device of the present invention has a plate-shaped antenna substrate formed in a loop shape close to a printed circuit board on which electrical components are mounted. and both ends thereof are connected to the printed circuit board, and an insulating layer with high heat resistance and hardness is formed with a uniform thickness by coating on the surface of the above-mentioned plate-shaped antenna board other than both ends connected to the printed circuit board. This is the configuration.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a side view showing the antenna according to this embodiment, FIG. 2 is a perspective view showing both ends of the antenna, and FIG. 3 is a partial sectional view of the antenna.

The antenna of this example is an improved version of the built-in antenna of a general radio paging receiver as shown in FIG. The same is true.

The characteristic structure of the antenna 10 of this embodiment is that a highly heat-resistant and hard insulating layer is uniformly coated not only on the outer surface but also over the entire surface of the printed board 1 except for both ends connected to the circuit. It was formed. As the insulating material, for example, epoxy resin, nylon resin, etc. are used.

The above coating is performed using the following method, unlike the conventional spray painting method.

First, both end portions 11, 11 shown in FIG. 2 are masked by taping or the like. Next, the entire antenna is coated by immersing it in a bathtub in which an insulating material such as epoxy resin or nylon resin is melted (dipping means). Alternatively, the heating may be performed by placing the heated antenna 10 in an atmosphere containing finely powdered insulating material so that the powder adheres to the antenna surface and simultaneously welds it (powder coating means). . According to such means, it is possible to form a uniform insulating layer 14, and it is possible to improve accuracy. Note that these methods have a sufficient track record of quality and accuracy in the field of IC manufacturing. According to these means, the insulating layer 14 having a thickness of about 0.1 mm can be formed.

In this way, as shown in FIG. 3, a silver plating layer 13 is formed on the surface of the antenna base material 12, and an insulating layer 14 is further formed on the entire surface (excluding both ends 11, 11) by coating. The antenna 10 can be manufactured. Note that both end portions 11, 11 are
It is connected to the printed board 1 by soldering in the conventional manner.

It should be noted that the present invention is not limited to the above-described embodiment, and can be implemented in other forms than the built-in antenna for the radio paging receiver shown in FIG. 4, for example. Furthermore, if the insulating material forming the insulating layer is colored black or the like, an appearance that makes dirt less noticeable can be obtained.

[Effects of the invention] As explained above, according to the invention, the entire surface of the antenna formed in a loop shape close to the printed circuit board, except for both ends connected to the printed circuit board, has excellent heat resistance and Since the insulating layer with high hardness is formed by coating, the insulator that is conventionally required can be omitted, thereby reducing costs and manufacturing time. Furthermore, since an insulating layer is formed on the entire surface (excluding both ends), there is no risk of oxidation or discoloration in the future even if you touch it with your fingers during manufacturing.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an antenna according to an embodiment of the present invention, Fig. 2 is a perspective view showing both ends of the antenna, Fig. 3 is a partial sectional view of the antenna, and Fig. 4 is a general FIGS. 5 and 6 are exploded perspective views showing the antenna mounting structure of a radio paging receiver, and are views showing conventional examples. 1... Printed board, 10... Antenna, 11...
...End portion, 12...Antenna base material, 13...Silver plating layer, 14...Insulating layer.

Claims (1)

[Scope of utility model registration request] A plate-shaped antenna board is formed in a loop shape close to a printed circuit board on which electrical components are mounted, and both ends thereof are connected to the printed circuit board, and a surface of the plate-shaped antenna board other than both ends connected to the printed circuit board. A built-in antenna for a small wireless device characterized by having a structure in which an insulating layer with high heat resistance and hardness is formed with a uniform thickness by coating.