JPH0810654B2 - Print coil - Google Patents

Description

The present invention relates to a print coil suitable for use in a motor, an objective lens driving device for an optical pickup, or the like.

[Conventional technology]

For example, as an objective lens driving device in an optical pickup, in Japanese Utility Model Laid-Open No. 59-164938, a print coil 1 as shown in FIG. 4A is bent as a driving coil to hold the objective lens as shown in FIG. 4B. A holder mounted on the outer periphery of the holder has been proposed. The printed coil 1 includes coils 3a to 3d made of copper formed on both sides of a flexible insulating sheet 2 by etching or plating, and through holes 4a to 4d connecting the coil portions on both sides, respectively.
It is composed of connecting portions 5a and 5b for connecting lead wires for supplying current to the coil portions 3a to 3d. The printed coil 1 as described above has an extremely light weight as compared with a coil formed by winding a conductive wire, and thus can reduce the weight of a movable part, which enables high-speed access and various shapes of patterns of various parts. Therefore, there is an advantage that the degree of freedom in design is increased.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional printed coil 1, when the conductor is bent as shown in FIG. 4B, the conductor portion does not extend, but the insulating sheet 2 extends. Is partially concentrated, for example, the insulating sheet 2 in the vicinity of the through holes 4a to 4d is cracked, so that the coil is broken or another coil is wound on the printed coil 1. However, there is a problem in that other coils may be broken or the print coil may be short-circuited. Such a problem also occurs when the print coil is mounted on the rotor or stator of the motor for use.

The present invention has been made by paying attention to such conventional problems, and even if it is bent or bent into an arbitrary shape,
An object of the present invention is to provide a printed coil that is appropriately configured so that the insulating sheet does not crack.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a printed coil formed by forming a conductor pattern in a coil shape on a flexible insulating sheet by etching, plating, or the like, wherein the conductor pattern and an inner portion of the coil formed of the conductor pattern. For bending of the insulating sheet including
It is characterized in that a dummy conductor is provided in the inner portion so that the strength is substantially uniform over the portion of the conductor pattern and the inner portion.

[Action]

In this way, if dummy conductors are provided to make the strength of the entire print coil substantially uniform, even if the print coil is bent or bent, or is heated by soldering or the like, the stress due to extension or expansion due to it does not occur. , It acts almost uniformly over the entire print coil, and does not act in a concentrated manner. Therefore, cracking of the insulating sheet can be effectively prevented.

〔Example〕

FIG. 1 shows a first embodiment of the present invention. This printed coil 11 is used by bending or bending in the width direction like the one shown in FIG. 4A.
A coil portion 13 made of a conductor such as copper formed by etching or plating on both sides of a flexible insulating sheet 12 as in FIG.
a to 13d, through-hole portions 14a to 14d for connecting the coil portions on both sides, and connecting portions 15a and 15b for connecting lead wires for supplying current to the coil portions 13a to 13d are provided, but in this embodiment, In order to make the strength of the entire print coil 11 substantially uniform, a coil portion 13b is provided between the coil portions 13a and 13b.
A plurality of dummy conductors 16 extending in the longitudinal direction are formed on the insulating sheet 12 between the coil portions 13c and 13c and between the coil portions 13c and 13d, and the insulating sheet 12 on the inner side of each coil portion is similarly formed. Multiple dummy conductors extending in the length direction
Forming 16. Also, the insulating sheet around the connection parts 15a, 5b
A plurality of dummy conductors 16 extending in the length direction and the width direction are formed on 12. These dummy conductors 16 are formed of the same material as the coil portions 13a to 13d at the same time by etching, plating or the like.

In this way, the dummy conductor 16 is provided and the print coil is
If the strength of the whole 11 is made substantially uniform, even if the insulating sheet 12 is bent in the width direction in each coil portion as shown in FIG. Occurrence can be effectively prevented. Note that FIG. 2 shows a state in which the coil portion 13c is bent. Further, even if the periphery thereof is heated by soldering the lead wires to the connection portions 15a and 15b, expansion in the periphery is suppressed by the dummy conductor 16 as compared with the case without this, so cracking or connection due to expansion Lifting of the parts 15a and 15b can also be effectively prevented. Further, by providing the dummy conductor 16 in this way, the thickness of the printed coil 11 can be made substantially uniform, so that when the coil is wound on the printed coil 11 in a superposed manner, it can be wound uniformly without being disturbed. Can be dressed. FIG. 3 shows a second embodiment of the present invention. This printed coil 21 is basically different from that shown in FIG. 1 in that the width of the flexible insulating sheet 12 is partially thinned, and the same reference numerals as those shown in FIG. Represents what you make. As described above, when the width of the insulating sheet 12 is partially thinned, the strength of this portion is weak, and the stress due to bending or bending is concentrated on this portion and the insulating sheet 12 is easily cracked. Therefore, in this embodiment, a dummy conductor 16 is formed in this narrow portion to reinforce the strength, thereby preventing concentration of stress. The print coil 21 shown in FIG. 3 is attached to a holder that holds the objective lens in the objective lens driving device of the optical pickup, and the notch 22 is for positioning with the holder. The holder is supported by four conductive wires so as to be displaceable in the focus and tracking directions with respect to the fixed member. In order to connect the holder to the four wires, the print coil 21 has a coil portion. 13a ~ 1
In addition to the connecting portions 15a, 15b with 3d, two connecting portions 15c, 15d are further provided, and one end of each of these four connecting portions 15a to 15d is attached to the fixing member at the other end. The holder is supported so as to be displaceable with respect to the fixed member by connecting each of them. Here, the connecting portions 15c and 15d are for wire connection and are not connected to the coil portion, and the power feeding to the coil portion is performed through the wires connected to the connecting portions 15a and 15b. In this embodiment, dummy conductors are not provided around the connecting portions 15a to 15d, but since the width of the insulating sheet 12 is narrow in these portions, the surroundings may be caused by heating when soldering the wires. The insulating sheet 12 is hardly cracked or lifted up, so that the dummy conductor may not be provided.

Also in this embodiment, as in the case of FIG. 1, since the strength of the entire print coil 21 is substantially uniform, the same effect can be obtained.

〔The invention's effect〕

As described above, according to the present invention, when the insulating sheet including the conductor pattern and the inner portion of the coil formed of the conductor pattern is bent, the strength is substantially uniform over the conductor pattern portion and the inner portion. As described above, since the dummy conductor is provided in the inner portion, the crack of the insulating sheet due to bending and bending can be effectively prevented, and the entire print coil is not enlarged.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention, FIG. 2 is a diagram showing an example of a mounting mode of the print coil shown in FIG. 1, and FIG. 3 is a diagram showing a second embodiment of the present invention. FIGS. 4A and 4B are views showing a conventional technique. 11 …… Print coil, 12 …… Insulation sheet 13a ～ 13d …… Coil part 14a ～ 14d …… Through hole part 15a, 15b …… Connecting part, 16 …… Dummy conductor 21 …… Print coil, 15c, 15d… … Connection 22 …… Notch

Claims (1)

[Claims] 1. A printed coil comprising a flexible insulating sheet having a conductor pattern formed in a coil shape by etching, plating, or the like, the insulating sheet including the conductor pattern and an inner portion of the coil formed of the conductor pattern. A printed coil, wherein a dummy conductor is provided on the inner portion so that the strength is substantially uniform over the portion of the conductor pattern and the inner portion against bending.