JPS5934155Y2 - printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printed wiring board, and particularly to a printed wiring board that is most suitable as a board for a measuring device such as an input switch board for a recorder.

A recorder using a resistance thermometer detects and records minute changes in resistance due to the temperature of the resistance thermometer.
A resistance change of approximately 400 mQ is converted into a temperature change of 1°C.

Therefore, if the wiring resistance from the resistance temperature detector to the recorder and the wiring resistance inside the recorder are not balanced with high accuracy, a large error will occur in the measured value.

In particular, if the printed wiring board used for the input switch has a width of 0°5 mm, the wiring will be 1 cm per 1 cm.
It has a relatively high resistance value of 0 to 15 m and Q, and the wiring in this input switch is one of the factors that determines the accuracy of the recorder.

This invention was developed in view of the above points,
By forming symmetrical wiring patterns on both the front and back sides of the board,
The purpose is to eliminate the influence of wiring resistance in measuring equipment, etc. by making the resistance value of the wiring pattern formed on the front side approximately equal to the resistance value of the wiring pattern formed on the back side. It is something.

Next, a first embodiment of the printed wiring board according to the present invention will be described with reference to the drawings.

1 in the figure is an input switch in which the printed wiring board according to the present invention is used, and this manual switch 1 is connected to the first board 2.
, a magnetic revolution disk 3, and a second board 4 are superimposed, and the first board 2 is arranged in pairs on a printed wiring board B having an opening 5 in the center. The configuration includes 12 sets of reed switches SF.

A wiring pattern P shown in FIG. 2 is formed on the front surface of the printed wiring board B, and a wiring pattern P' shown in FIG. 3 is formed on the back surface.

That is, the wiring patterns P and P' formed on this printed wiring board B are symmetrical in shape, and the wiring pattern P on the front surface B1 of this printed wiring board B is explained with reference to FIG. A ring-shaped wiring P1 is formed on the outer periphery of the opening 5, and the ring-shaped wiring P1
Twelve radial wiring P2 are formed extending radially from the outer periphery of the radial wiring P2.

The radial wiring P2 has the same length, and a small circular connection end P3 is formed at the tip thereof to which each end of the reed switch SF is connected.

Twelve small circular connection ends P4 to which the other end of the reed switch SF is connected are formed on the outer periphery of the connection terminal part P3, and each connection end P4 is connected to the connection end P3.
．． It is connected to an arcuate wiring P5 disposed between P4, and is connected to an external connection terminal portion P6 formed on one side of the printed wiring board B via the arcuate wiring P5.

Further, the ring-shaped wiring P1 is connected to an external connection terminal portion P6 via a connection wiring P7.

A wiring pattern P' that is symmetrical to the wiring pattern P described above.
are formed on the back surface B2 of the printed wiring board B as shown in FIG. 3, and the connection ends P'3. P'4 and each connecting end P3. formed on the surface B1. P4 and P4 are provided at positions facing each other as shown in FIG.

The small circular connection end P3. Inside P4 is the connection end P'3 on the back side. Two reed switch terminal insertion holes 6 and 7 reaching up to P'4 are formed, and an insulating part 8 formed by peeling off the wiring conductor is formed around one of the reed switch terminal insertion holes 7. , the terminal of the node switch SF inserted and fixed into the switch terminal insertion hole 7 by this insulating part 8 is as follows.
Connection end P3. It is electrically insulated from P4.

Further, the terminal of the reed switch SF inserted and fixed into the other switch terminal insertion hole 6 is connected to the connection end P3. It is electrically integrated with P4.

Furthermore, the connection end P'3 on the back side. An insulating part 8' formed by peeling off the wiring conductor is formed around the switch terminal through hole 6 at P'4, and the reed switch SF is inserted and fixed into the switch terminal through hole 6 by this insulating part 8'. The terminal is connected to the connecting end P'3. The terminal of the reed switch SF, which is electrically insulated from P'4 and inserted and fixed into the other switch terminal insertion hole 7, is connected to the connecting end P'3. P′
It is electrically integrated with 4.

As shown in FIG. 5, 12 sets of two reed switches SF1 to 5F12 are disposed on the surface of the substrate B on which the above-mentioned wiring patterns P and P' are formed. Each of the reed switches SF, ~5F12 is installed with its longitudinal direction inclined at an angle of approximately 45 degrees with respect to the radial direction centered on the central opening 5, and thereby, the reed switches SF1 ~ SF1□ is arranged as a whole along a spirally wound line.

Further, the second board 4 has the same wiring patterns P, P' and reed switches SR as the first board 2 described above, and the second board 4 and the first board 2 have the same wiring patterns P, P' and a reed switch SR. They are fixed to each other via a spacer 9 with surfaces B1 on which the respective reed switches are disposed facing each other.

Therefore, each reed switch SF on the first board 2 and each reed switch SR on the second board 4 have inclinations opposite to each other, and are orthogonal to each other as shown in FIG. Become.

The magnetic revolution disk 3 provided between the first substrate 2 and the second substrate 4 has its center fixed to a rotating shaft 10 protruding from the center opening 5 of the first substrate 2. The rotating shaft 10 is rotatably supported by a frame 11 provided on the back of the first substrate 2.
0 is connected to a drive motor (not shown) via a transmission gear 10a.

On the other hand, a magnet rotation shaft 1 is located at a position corresponding to the reed switches SF and SR on the magnet revolution disk 3.
2 is pivotally mounted, and this magnet rotating wheel 12 has a
A magnet M is embedded at the center of rotation, and the magnet M is arranged so that its magnetic pole direction rotates as the magnet rotating wheel 12 rotates.

Furthermore, four engaging levers 12a are formed protruding from the outer periphery of this magnet rotating wheel 12, and the retaining levers 12a
and the retaining pin 13 implanted on the first substrate 2 constitute an intermittent rotation device, and the engagement lever 12
When a engages with the engagement pin 13, the magnetic rotating wheel 12
A positioning spring 14 is attached to the revolution disk 3 for regulating the rotational position of the magnet rotary wheel 12 so that it is rotated by 90 degrees.

In addition, the above-mentioned No. 1. A connector 15 electrically connected to the external connection terminal part P6 is attached to the second board 2, 4 at the location of the external connection terminal part P6, and the switching device 1 is connected to the 10th As shown in the figure, it is connected to resistance temperature detectors R(1) installed at various locations.

Next, the operation of the switching device having the above-mentioned configuration will be explained.

The node switches SF and SR have operating regions shown in FIG.
- In relation to the magnetic pole directions of M, when they are substantially orthogonal to each other, they are OFF, and when they are substantially aligned, they are ON, and the ON region is narrower, about 30' from a completely aligned state. .

Therefore, as shown in FIG. 9, the magnetic pole of the magnet M matches the longitudinal direction of the reed switch SR, and the reed switch SF
If the reed switch S is perpendicular to the longitudinal direction of
When R is in the ON state, the reed switch SF is in the OFF state.

When the revolution disk 3 is rotated and the magnet M revolves around the rotating shaft 10, the reed switches SF1 to SF1□ of the first board 2, which are aligned with the magnetic pole direction of the magnet M, are sequentially activated. The reed switch SR on the second board 4 is turned on and off, and since the longitudinal direction of the reed switch SR on the second board 4 is perpendicular to the magnetic pole direction of the magnet M, the reed switch SR can be turned ON even if the reed switch SR is close to the magnet M. is maintained in the OFF state.

Next, as shown in FIG. 7, after the magnet M turns on the reed switch SF1□, the engagement lever 12a of the magnet rotating wheel 12 engages with the engagement pin 13, and the magnet rotating wheel 12 It is forced to rotate 90 degrees.

In this way, the magnetic pole direction of the magnet M is rotated by 90 degrees, and the longitudinal direction of the reed switch SR now coincides with the magnetic pole direction.

In this state, the magnet) M revolves, so the second substrate 4
The reed switches SR are sequentially turned ON and OFF, but at this time, since the longitudinal direction of the reed switch SF on the first board 2 is orthogonal to the magnetic pole direction of the magnet M, the magnet M is connected to the reed switch SF. Even if it comes close, it will not be turned on and will remain in the OFF state.

By repeating the above operations, the 24 sets of reed switches SF and SR in the switching device 1 are sequentially turned on and off.

Further, the wiring patterns P and P' formed on each of the substrates 2 and 4 have a relatively high resistance value Pr.

P'r, for example, the width of the wiring pattern is 0.5
In the case of mm, it has a resistance value of 10 to 15 mQ per 1 cm.

However, since the wiring patterns P and P' are formed in a symmetrical shape on both the front and back sides of the board B, the wiring pattern P on the front surface and the wiring pattern P' on the back surface have almost the same resistance value. are doing.

Therefore, if one reed switch in a set of two reed switches SF and SR is connected to the wiring pattern P on the front surface, and the other reed switch is connected to the wiring pattern P' on the back surface, the result shown in FIG. As shown, the resistance value Pr of a pair of wires connected to both ends of the resistance temperature sensor R(t)
, P'r will match each other.

Therefore, the resistance change of the temperature sensing resistor R(t) is not affected by the resistance values of the wiring patterns P and P', and can be detected with high accuracy.

As explained above, according to the present invention, symmetrical wiring patterns are formed on both the front and back sides of the board, and the resistance value of the wiring pattern formed on the front side and the resistance value of the wiring pattern formed on the back side are Since the resistance values are approximately the same, by using the opposing front and back wiring patterns as a pair, there is an effect that the wiring resistance can be balanced with high accuracy.

Therefore, when used as a printed wiring board for a measuring device that is affected by minute changes in resistance value, such as a recorder using a resistance temperature sensor, it has the effect of significantly improving measurement accuracy.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of a switch using the printed wiring board according to this invention, Fig. 2 is a front view showing the wiring pattern on the front side of the printed wiring board, and Fig. 3 shows the wiring pattern on the back side of the printed wiring board. 4 is an explanatory diagram showing the relationship between the wiring patterns on the front and back sides, FIG. 5 is a front view of the printed wiring board with the reed switch attached, and FIG. 6 is a sectional view of the switch. , Fig. 7 is an explanatory diagram of the operation of the switching device, Fig. 8 is an explanatory diagram showing the operating area of the reed switch, Fig. 9 is an explanatory diagram showing the relationship between the arrangement of the reed switch and the relationship between the magnets, and Fig. 10 is an explanatory diagram of the present invention. FIG. 2 is a circuit diagram showing a circuit configuration when the printed wiring board according to the present invention is used as a switch of a recorder. B...printed wiring board, B1...front surface of printed wiring board, B2...back surface of printed wiring board, P...formed on front surface Wiring pattern, P'... Wiring pattern formed on the back side.

Claims (1)

[Scope of utility model registration request] Wiring patterns that are symmetrical to each other are formed on each of the front and back surfaces of the board, and the resistance value of the wiring pattern formed on the front surface is approximately equal to the resistance value of the wiring pattern formed on the back surface. A printed wiring board characterized by: