JP2007108115A - Flexible printed circuit board, magnetic encoder using it, and motor having it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible printed circuit board for facilitating curvature for being attached to a mechanical component by enhancing a degree of freedom of wiring in the flexible printed circuit board, and to provide a magnetic encoder using the flexible printed circuit, and a motor having it. <P>SOLUTION: The flexible printed circuit board 8 has a Hall element mounting part 17 for mounting a Hall element 16 and parts extending to both sides from the Hall element mounting part 17 respectively. The flexible printed circuit board 8 comprises forming a GND beta pattern part 18 by wiring the beta pattern being a GND level of a signal on an extension part, and being wound a plurality of times so as to sandwich the Hall element mounting part 17 by the GND beta pattern part 18. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flexible printed circuit board, a magnetic encoder including the flexible printed circuit board, and a motor including the magnetic encoder.

As shown in FIG. 6, the magnetic encoder 1 is generally attached to the non-load side of the motor M and includes a fixed portion 2 and a rotating portion 3. The fixed portion 2 includes a substrate support 7 attached to a fixed body 6 composed of, for example, an encoder frame 4 and a non-load side bracket 5 of a motor M, and a flexible printed circuit board attached to the substrate support 7. 8A. A magnetic field detecting element 9 is attached to the flexible printed board 8A.
The rotating unit 3 includes a magnetic drum 11 attached to the output shaft 10 of the motor M. The magnetic field detection element 9 and the magnetic drum 11 are opposed to each other in the radial direction with a gap (for example, Patent Document 1).
Further, as shown in FIG. 7, the conventional flexible printed circuit board 8A has a plurality of wirings 12, 13, and 14. Of these, the wiring 14 located at at least one end is set to the GND level. As shown in FIG. 8, the width of the wiring 14 is increased, and the wide portion is bent to enclose the other wirings 12 and 13 (for example, Patent Document 2). Reference numeral 15 denotes an adhesive.
Thus, in the conventional flexible printed circuit board 8A, the wiring width of one wiring 14 is widened so that the other wirings 12 and 13 are wrapped and magnetically shielded.
JP 2004-191126 A JP-A-62-269389

However, such conventional techniques have the following problems.
(1) The flexible printed circuit board in the conventional magnetic encoder has a structure in which the wiring located at the end is wound around another wiring with the GND level, and the wiring located at the end can be used as a signal wiring. Can not. For this reason, there is a restriction on the wiring routing in the flexible printed circuit board.
(2) When the flexible printed circuit board is attached to other mechanical parts, the three flexible printed circuit boards are stacked, so that if the thickness of the copper foil of the flexible printed circuit board is increased, it becomes hard and difficult to bend into an arbitrary shape.
The present invention has been made in order to solve such a problem. A flexible print which can increase the degree of freedom of wiring in a flexible printed circuit board and can be easily bent for attachment to a mechanical component. It is an object of the present invention to provide a magnetic encoder using the flexible printed circuit board and a motor equipped with the magnetic encoder.

In order to solve the above problems, the present invention is configured as follows.
The invention of a flexible printed circuit board according to claim 1 is a flexible printed circuit board having a Hall element mounting portion for mounting a Hall element, and portions extending from the Hall element mounting portion on both sides, respectively, and a signal GND in the extension portion. A level solid pattern is wired to form a GND solid pattern portion, and the Hall element mounting portion is wound a plurality of times so as to be sandwiched between the GND solid pattern portions.
According to a second aspect of the present invention, there is provided a flexible printed board having a Hall element mounting portion for mounting a Hall element and portions extending from the Hall element mounting portion on both sides, respectively. A GND solid pattern portion is formed by wiring a pattern, and the GND solid pattern portion is wound a plurality of times so as to overlap the Hall element mounting portion.
According to a third aspect of the present invention, there is provided a flexible printed board having a Hall element mounting portion for mounting a Hall element, and portions extending from the Hall element mounting portion on both sides, respectively, and the flexible printed circuit board having the Hall element mounting portion. 1 sheet and at least one flexible printed circuit board wired with a solid GND pattern on the entire surface, wound in order so as to overlap or sandwich the flexible printed circuit board having the Hall element mounting portion, A pad for connecting the GND of each flexible printed board with solder or the like is provided.
According to a fourth aspect of the present invention, the GND solid pattern of the GND solid pattern portion is wired in a mesh shape.
According to a fifth aspect of the present invention, there is provided a magnetic encoder comprising: a fixed portion and a rotating portion; and the fixed portion is a substrate support attached to a fixed body comprising an encoder frame, a motor bracket, and the like. And a flexible printed circuit board having a magnetic field detection element attached to the substrate support, and the rotating portion includes a magnetic drum facing the magnetic field detection element in a radial direction with a gap interposed therebetween. A magnetic encoder is characterized in that the flexible printed circuit board according to any one of claims 1 to 4 is provided on the fixed body.
According to a sixth aspect of the present invention, the magnetic encoder according to the fifth aspect is characterized in that the fixed portion is attached to the bracket of the motor and the rotating portion is attached to the output shaft of the motor. .

According to the first and second aspects of the invention, it is possible to easily bend the flexible printed circuit board attached to the member. Therefore, the GND pattern provided in the extended portion can be overlapped or wound around the wiring pattern of the detection signal of the Hall element, and external noise superimposed on the detection signal can be reduced.
According to the third aspect of the present invention, the flexible printed circuit board on which the Hall element is mounted and the flexible printed circuit board having the GND pattern can be individually attached to the members, and attachment work can be facilitated. .
According to the fourth aspect of the invention, since the GND solid pattern is wired in a mesh shape, the material cost can be reduced and the flexibility can be improved.
According to the fifth aspect of the present invention, it is possible to easily bend the flexible printed circuit board capable of reducing external noise during the mounting operation to the magnetic encoder.
According to the sixth aspect of the present invention, the motor can be provided with a magnetic encoder that can reduce material noise, reduce assembly noise, and reduce external noise.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a structural diagram showing a flexible printed circuit board according to a first embodiment of the present invention.
FIG. 2 is an assembly diagram illustrating a state when the flexible printed board in FIG. 1 is attached to a substrate support. Since the configuration other than the flexible printed circuit board 8 is basically the same as that of the prior art, the description thereof is omitted.
In FIG. 1, the flexible printed circuit board 8 includes a Hall element mounting portion 17 on which the Hall element 16 is mounted, a GND solid pattern portion 18 that extends from the Hall element mounting portion 17 on both sides, and the Hall element mounting portion. 17 and a signal lead-out part 19 connected to the terminal 17. The Hall element mounting portion 17 is in the center, and the GND solid pattern portions 18 are disposed on both sides thereof. The lengths of the Hall element mounting portion 17 and the GND solid pattern portion 18 are the length of one round of a mechanical component (substrate support 7 in the case of a magnetic encoder) around which the flexible printed circuit board 8 is wound. It has become.
As shown in FIG. 2, the flexible printed circuit board 8 is configured by winding the Hall element mounting portion 17 a plurality of times so as to be sandwiched between GND solid pattern portions 18.
The difference between the present invention and Patent Document 2 is that it is not necessary to provide wiring to be used as the GND solid pattern portion 18 at the end portion, and the thickness of the flexible printed circuit board 8 is one. .

FIG. 3 is a structural diagram of the flexible printed circuit board 8 in the second embodiment.
In FIG. 3, the GND pad 20 a of the Hall element mounting portion 17 in the flexible printed circuit board 8 and the GND pad 20 b of the GND solid pattern section 18 are arranged so as to overlap when the flexible printed circuit board 8 is wound. is there.

FIG. 4 is an assembly diagram illustrating a state when the flexible printed circuit board 8 in FIG. 3 is attached to the substrate support 7.
In FIG. 4, by soldering the GND pad 20a of the Hall element mounting portion 17 for mounting the Hall element 16 and the GND pad 20b of the GND solid pattern portion 18, the Hall element mounting portion 17 has a GND solid pattern. The structure overlaps the portion 18. If two flexible printed boards having the GND solid pattern portion 18 are used, the Hall element mounting portion 17 can be sandwiched between the GND solid patterns 18.
In the figure, 21 is solder.

FIG. 5 is a structural diagram showing the flexible printed circuit board 8 in the third embodiment.
In the third embodiment, the GND solid pattern 18 is configured by wiring in a mesh shape. By doing in this way, cost can be reduced and flexibility can also be improved.

Thus, in the present invention, since it is not necessary to limit the wiring located at the end to GND, the degree of freedom of wiring is increased, and the flexible printed board 8 having a thickness of one sheet is wound, so that the mounting work It is easy to bend, and the GND solid pattern 18 is overlapped or wound so as to be sandwiched between the Hall element mounting portion 17, so that external noise superimposed on the detection signal of the Hall element 16 can be reduced. .
Needless to say, the flexible printed circuit board 8 of the present invention can be applied to other than the encoder.

  Since the number of Hall elements mounted can be increased by increasing the degree of freedom of wiring, it can also be applied to multi-signal detection.

1 is a structural diagram illustrating a flexible printed circuit board according to a first embodiment of the present invention. It is an assembly drawing which shows the state at the time of attaching the flexible printed circuit board in FIG. 1 to a board | substrate support body. It is structural drawing which shows the flexible printed circuit board in a 2nd Example. It is an assembly drawing which shows the state at the time of attaching the flexible printed circuit board in FIG. 3 to a board | substrate support body. It is a structure figure of the flexible printed circuit board in a 3rd Example. It is a sectional side view which shows the principal part of the motor with an encoder in a prior art. It is a structural diagram which shows the flexible printed circuit board in a prior art. It is a sectional side view which shows the flexible printed circuit board in a prior art.

Explanation of symbols

M Motor 1 Magnetic encoder 2 Fixed part 3 Rotating part 4 Encoder frame 5 Motor anti-load side bracket 6 Fixed body 7 Substrate support 8, 8A Flexible printed circuit board 9 Magnetic field detection element 10 Motor output shaft 11 Magnetic drum 12, 13, 14 Wiring 15 Adhesive 16 Hall element 17 Hall element mounting part 18 GND solid pattern part 19 Signal lead-out part 20a GND pad 20b of Hall element mounting part GND pad 21 of GND solid pattern part Solder

Claims (6)

Hall element mounting part for mounting the Hall element;
In the flexible printed circuit board having a portion extending on both sides from the Hall element mounting part,
A solid solid pattern portion is formed by wiring a solid pattern having a signal GND level to the extended portion,
A flexible printed board characterized in that the Hall element mounting portion is wound a plurality of times so as to be sandwiched between GND solid pattern portions. Hall element mounting part for mounting the Hall element;
In the flexible printed circuit board having a portion extending on both sides from the Hall element mounting part,
A solid solid pattern portion is formed by wiring a solid pattern having a signal GND level to the extended portion,
A flexible printed circuit board comprising a plurality of windings so that the GND solid pattern portion overlaps the Hall element mounting portion. Hall element mounting part for mounting the Hall element;
In the flexible printed circuit board having a portion extending on both sides from the Hall element mounting part,
One flexible printed circuit board having the Hall element mounting part and at least one flexible printed circuit board wired with a solid GND pattern, and overlapping the flexible printed circuit board having the Hall element mounting part, Alternatively, a flexible printed circuit board provided with a pad that is wound in order so as to be sandwiched and connects the GND of each flexible printed circuit board with solder or the like.   The flexible printed circuit board according to any one of claims 1 to 3, wherein the GND solid pattern of the GND solid pattern portion is wired in a mesh shape. It consists of a fixed part and a rotating part,
The fixed portion is a substrate support attached to a fixed body composed of an encoder frame and a motor bracket, and the like.
A flexible printed circuit board having a magnetic field detection element attached to the substrate support;
And in the magnetic encoder which comprises the magnetic drum which the above-mentioned rotation part counters in the diameter direction via the above-mentioned magnetic field detection element, and a gap,
A magnetic encoder comprising the flexible printed circuit board according to any one of claims 1 to 4 on the fixed body.   6. A motor having the magnetic encoder according to claim 5 attached to a bracket of the motor and a rotating part attached to an output shaft of the motor.

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