JPH05183241A - Wiring substrate and mobile object telecommunication equipment using same - Google Patents

Abstract

PURPOSE:To provide the title wiring substrate and mobile object telecommunication equipment using the same capable of coping with the partial modification in circuit specification. CONSTITUTION:A local oscillation circuit deciding the receiving frequency of a bell jar is packaged in the region encircled by multiple through holes 1 in the lefthand lower corner. A solder pad (a) is provided in a part of through holes 1 the inner walls of which are not metallized. In order to change the receiving frequency, the region wherein the local oscillation circuit is packaged is cut off from the main body part by pressing down a part of the through holes 1. Finally, the other substrate whereon the local oscillation circuit having specific receiving frequency characteristics is mounted is soldered into the main body part using the through holes 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board, and more particularly to a wiring board on which some electronic components mounted on the board can be easily replaced and a mobile communication device using the wiring board.

[0002]

2. Description of the Related Art In mobile communication, such as a paging system, the frequency of a transmission signal (line frequency) is determined by the service area.
It suffices to be able to receive only one line frequency, and normally there is no need to change the receive frequency.

Therefore, a crystal oscillator circuit having a fixed oscillation frequency is usually used for the local oscillator circuit of the pager. However, if the received frequency of the pager stocked by the paging service company is different from the line frequency of the service area desired by the user, it is necessary to change the received frequency of the pager.

Further, after the pager is sold out, if the user desires to change the service area, it is necessary to change the reception frequency. The reception frequency of the pager is uniquely determined by the oscillation frequency of the local oscillation circuit of the reception unit.Therefore, when changing the reception frequency, at least the crystal oscillator and some of the electronic components that make up the local oscillation circuit should be used. It is necessary to replace the chip capacitor and some chip coils. When a narrow band filter such as a SAW filter is used as a bandpass filter of the frequency conversion circuit unit to which the signal from the local oscillation circuit is supplied, it is also necessary to replace the filter at the same time.

Therefore, conventionally, the local oscillation circuit is built in a small wiring board, and this wiring board is connected to the wiring board of the main body by a pin connector or the like, which can cope with the above-mentioned change of the reception frequency. It is known to do so.

In this method, the work of switching the frequency is easy because it is only necessary to replace the wiring board unit on which the local oscillation circuit is mounted, but the wiring board for the local oscillation circuit and the wiring board of the main body are separate members. However, there is a drawback that the cost is increased because a pin connector or the like is required for connecting those wiring boards.

Further, when both wiring boards are connected by a pin connector, the mechanical strength of the connection between the wiring boards and the reliability of the electrical connection are higher than those in which all the electronic components are soldered to one wiring board. Has the drawback of being low.

[0008]

It is an object of the present invention to provide a wiring board having excellent mechanical strength and electrical reliability and capable of easily exchanging some electronic components as required, and a movement using the wiring board. It is to provide a body communication device.

[0009]

The gist of the present invention is to provide a plurality of through holes around the area of a wiring board on which a specific electronic component is mounted to separate the area from the main body of the wiring board. When it becomes necessary to replace a specific electronic component, part of the wiring board is separated from the through hole, and another wiring board on which the component to be replaced is mounted is soldered to the main body of the wiring board, etc. It is that it can be connected by.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of a wiring board according to an embodiment of the present invention. This wiring board is a wiring board for a pager, and is equipped with a large number of electronic components that constitute an electronic circuit of the pager.

An antenna 2 for receiving a radio signal from a base station, an IDROM 3 for storing an ID code, and a decoder are provided in the main body portion of the wiring board other than the area surrounded by the through hole 1 (the area at the lower left corner of the board). An LSI 4 having a built-in circuit and a control circuit, a speaker 5 for informing a call, a power switch 6, and other chip parts such as resistors and capacitors are mounted.

In a region surrounded by a plurality of through holes in the lower left corner of the wiring board, a crystal oscillator 7, a chip component 8 such as a resistor, a coil, a capacitor, and a local oscillator circuit including a trimmer capacitor 9 are mounted. ing.

The through holes 1 are formed in the pattern of the-power supply line, those formed in the pattern of the + power supply line, those formed in the pattern of the signal line, and those formed in the solder pad. At least the inner walls of the through holes formed therein are metallized.

When changing the reception frequency of the pager using the above wiring board, first, force is applied to the portion where the through hole 1 is provided, and the portion where the local oscillation circuit is mounted is set to the main body. Separate from the section.

Next, another substrate (a substrate having the same size and the same wiring as the separated substrate) on which the local oscillation circuit of the desired reception frequency is mounted is used by using the wiring pattern of each line and the solder pad. Solder to.

2 (a) and 2 (b) are views showing a cross section of the through hole 1, FIG. 2 (a) shows a state before being separated from the through hole 1, and FIG. 2 (b) is a substrate. 2 shows a state in which another substrate is soldered to the main body after a part of the is separated from the through hole 1.

When a force is applied to the through hole 1 portion to break the substrate and separate the portion, the semicircular through hole 1 remains on the cut surface of the main body portion. Similarly, the other board to be replaced is a board separated from the through hole 1 portion of another wiring board, so that the semicircular through hole 1 remains on the cut surface. Therefore, by soldering the two semicircular through holes 1 in contact with each other, the two substrates can be easily connected. At this time, if the inner wall of the through hole 1 is metallized and solder pads are formed around it, soldering can be facilitated.

In the wiring board of this embodiment, another board can be easily soldered to the main body portion by utilizing the through hole 1 for separating a part of the board, and therefore, it should be replaced as in the conventional case. Since it is not necessary to connect the board and the main body with a connector, the cost can be reduced. Further, the mechanical and electrical connection can be made more reliable not only before disconnecting a part of the wiring board but also after connecting the replaced another board.

At this time, soldering can be facilitated by providing a solder pad as shown in FIG. 1 in a part or all of the through hole 1. Further, by soldering the inner surface of the through hole 1, the connection strength of the solder can be improved.

The board to be replaced when changing the reception frequency is, for example, one of the replacement wiring board units having a plurality of the same wiring patterns formed, that is, a plurality of replacement board portions formed in one through hole. It may be separated, and a local oscillation circuit having a desired reception frequency may be mounted on the separated board, or a board on which an unnecessary local oscillation circuit, which is separated from another pager wiring board, is mounted may be used.

In the above-mentioned embodiment, the electrical and mechanical connection between the substrate replaced by solder and the main-body substrate portion was made. However, the mechanical connection is made by a resin adhesive, and only the electrical connection is made by soldering. Alternatively, another conductive adhesive may be used.

Further, although the above embodiment describes the wiring board used in the pager, the present invention can be applied not only to the pager but also to the wiring board used in other devices.

[0023]

According to the present invention, a through hole is provided around a predetermined area of a wiring board on which a specific electronic component that may be replaced is mounted, and after mounting the electronic component, the specific electronic component is replaced. Only when it is necessary to do so, the board is separated from the through-hole portion, and for example, the board on which another electronic component is mounted is soldered to the main body using the through-hole, thus reducing the board cost. be able to. Further, since it is not necessary to connect the main body portion and the exchanged substrate with a connector or the like, the cost can be reduced and the mechanical strength and the reliability of electrical connection can be improved.

[Brief description of drawings]

FIG. 1 is an external view of a wiring board according to an embodiment.

FIG. 2 is a sectional view of a through hole portion. 1 Through hole 7 Crystal oscillator

Claims (4)

[Claims] 1. A wiring board on which a wiring pattern for electrically connecting electronic components to be mounted is formed, wherein the wiring board is provided around the area where a specific electronic component of the wiring board is mounted. A wiring board having a plurality of through holes for separating from the main body of the. 2. The wiring board according to claim 1, wherein a solder pad is formed around at least a part of the plurality of through holes. 3. The wiring board according to claim 2, wherein an inner surface of at least a part of the plurality of through holes is metallized. 4. A mobile communication device using the wiring board according to claim 1, 2 or 3, wherein the electronic component mounted in the area which can be separated by the through hole corresponds to a transmission and / or reception line frequency. A mobile communication device, which is an electronic component that constitutes an oscillation circuit that generates a frequency signal.