JPH05299799A - Printed wiring board - Google Patents

Abstract

(57) [Abstract] [Object] The present invention relates to a printed wiring board that is widely used in the circuit configuration of various electronic devices. The printed wiring board unit can be downsized, and wiring can be performed without damaging the insulating base material and mounted components. The purpose is to easily cut the specified position of the pattern. [Structure] An electrical cutting portion is provided at a portion of the wiring pattern 12 formed on the surface of the insulating base material 1 where circuit opening is required.
12a is provided, and the cutting portion 12a is connected by the solder 13 having excellent conductivity, if necessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board which is widely used in the circuit construction of various electronic devices.

Recently, some functions of the print unit have been selected and used in accordance with the multi-functionalization of the print unit mounted in a computer system or the like, and the print unit may be used as an address bus, a data bus or the like. In the case of using the type method, it is necessary to set the address of a printed wiring board (hereinafter abbreviated as a wiring board).

Therefore, a small switch is mounted on the wiring board and the circuit is cut or closed by turning the switch on or off, or a short circuit (shorting pin and contact piece) is specially mounted, or these When no special setting means is provided, the wiring pattern is physically cut with a blade or the like to open the closed circuit.

However, a small switch or a short circuit is required to occupy its own area, which hinders the miniaturization of the print unit. Moreover, when the wiring pattern is physically cut by a blade or the like, the wiring board and the surroundings are mounted. Since it is necessary to take care not to damage the parts and the workability is poor, it is possible to easily cut the specified position of the wiring pattern without damaging the wiring board and mounting parts, and for mounting a small switch or short circuit. There is a demand for a printed wiring board having the smallest area.

[0005]

2. Description of the Related Art A printed wiring board that has been widely used in the past is an insulating substrate for mounting a circuit opening / closing member 3 such as a small switch or a short circuit as shown in FIG. 3 to open or close a wiring pattern 2. Material 1
Pads 2-1 of 1.3 mm square for connecting the circuit opening / closing member 3 are formed at regular intervals on the surface position of, and are connected to the wiring pattern 2 of 0.2 mm width, and other wiring patterns 2 are connected. Outside the mounting area of the circuit opening / closing member 3, high density is formed at intervals of 0.1 mm, for example.

Since the wiring pattern 2 formed on the surface of the insulating base material 1 is rarely changed after being set to sheet / open once, the mounting area for the circuit opening / closing member is not provided as described above. Further, the wiring pattern 2 is formed at a high density, and the place where the circuit needs to be opened is physically cut by a blade or the like.

[0007]

The problem with the conventional printed wiring board described above is that a small switch or a short circuit circuit opening / closing member 3 is mounted on the surface of the insulating substrate 1 from the beginning as shown in FIG. When the wiring pattern 2 and the pad 2-1 are formed so as to be possible, a large space for mounting the circuit opening / closing member 3 is required, which causes a problem that the miniaturization of the print unit is hindered.

When the wiring pattern 2 formed on the surface of the insulating base material 1 is cut to open the closed circuit, the place where the circuit opening of the wiring pattern 2 is required is physically cut with a blade or the like. Since it has been cut into pieces, there is a possibility that electronic tools (not shown) mounted around the insulating base material 1 and the cut portion may be damaged by this blade, etc. There is also a problem that the workability of cutting is very poor.

In view of the above-mentioned problems, the present invention can reduce the size of the printed board unit, and can easily cut the specified position of the wiring pattern without damaging the insulating base material and the mounted parts, thus improving the reliability. The purpose of the present invention is to provide a new printed wiring board that can be used.

[0010]

According to the present invention, as shown in FIG. 1, an electrical cutting portion 12a is provided in a portion of a wiring pattern 12 formed on the surface of an insulating base material 1 at a place where circuit opening is required. , The cutting portion 12a is connected by the solder 13 having excellent conductivity.

[0011]

In the present invention, as shown in FIG.
Since the cutting portion 12a provided at the place requiring the circuit open is connected by the solder 13 to form the closed circuit, by heating the connection place by the arbitrary solder 13 provided for selecting the function, Since the closed circuit that can be easily removed is open, the specified position of the wiring pattern can be cut without damaging the insulating base material and mounted components, and the mounting of small switches or short circuits is not required and the printed circuit board unit can be made smaller. It becomes possible to measure.

[0012]

Embodiments of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a side sectional view showing a printed wiring board according to this embodiment, and FIG. 2 is a side sectional view of a second embodiment. In the figure, the same members as those in FIG. 3 have the same symbols.

In the first embodiment of the present invention, when some functions of the print unit are selected as shown in FIG. 1 (a), for example, in the case of using a bus type system such as an address bus or a data bus, Electrically non-conducting cuts of about 1 mm for each location where the closed circuit of the wiring pattern 12 of 2 mm width wired on the surface of the insulating base material 1 is opened.
12a is provided, and the cut portion 12a is connected by a low melting point metal having excellent conductivity such as solder 13 as shown in FIG. 1 (b) to form a closed circuit.

Further, in the second embodiment, as shown in FIG. 2, a diameter of 0.2 mm which is approximately equal to the width of the wiring pattern 12 is provided on the upper surfaces of the end edges of the cutting portions 12a provided on the wiring pattern 12, which are opposed to each other. And solder the wire piece of about 3 mm in length with excellent conductivity, or the connecting piece 23 made of a thin plate of about 0.2 mm width and about 3 mm in length with excellent conductivity. Thus, the connection piece 23 conducts to form a closed circuit.

As a result, when some functions are selected by opening the closed circuit, in the first embodiment, the closed circuit of the wiring pattern 12 is opened as shown in FIG. 1 (b). The solder 13 of the cut portion 12a provided is heated and melted. The connection piece 23 can be removed by removing it to make it open, and in the second embodiment, by melting the solder 13 conducted through the connection piece 23, the area for mounting a small switch or short circuit is unnecessary and printing is possible. The plate unit can be downsized, and the specified position of the wiring pattern can be easily cut without damaging the insulating base material and the mounted components.

The above description is based on the illustrated embodiment, but the present invention is not limited to the embodiment described above,
For example, in order to firmly bond and connect the solder 13 applied to the cut portion 12a of the wiring pattern 12 to the insulating base material 1,
A recess may be formed in the cutting portion 12a.

[0017]

As is apparent from the above description, according to the present invention, the printed board unit can be miniaturized with an extremely simple structure, and the designated position of the wiring pattern can be set without damaging the insulating base material and the mounted components. It is possible to provide a printed wiring board which has advantages such as easy cutting, and which can be expected to be significantly economical and highly reliable.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a printed wiring board according to a first embodiment of the present invention.

FIG. 2 is a side sectional view showing a second embodiment.

FIG. 3 is an enlarged plan view showing a conventional printed wiring board.

[Explanation of symbols]

 1 is an insulating base material, 12 is a wiring pattern, 12a is a cut portion 13 is solder, 23 is a connection piece,

Claims (2)

[Claims] 1. A cutting part (12a) to be electrically cut is provided in a place where the wiring pattern (12) formed on the surface of the insulating base material (1) needs to be opened, and if necessary, the cutting part (12a) is provided. A printed wiring board characterized in that the cut portion (12a) is connected by a low melting point metal (13) having excellent conductivity. 2. The printed wiring board according to claim 1, wherein the cut portion (12a) is connected by soldering a connection piece (23) having excellent conductivity.