JPH047114B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a new motor stator mounting wiring board, and particularly to a new motor stator mounting wiring board that has less warpage and can make the gap with the motor rotor small and uniform. The present invention aims to provide a stator mounting wiring board.

BACKGROUND ART AND PROBLEMS The motor used in electronic devices such as video tape recorders has a plurality of coils constituting a stator mounted on a printed wiring board, and the stator is rotatably assembled on the printed wiring board. There is a motor that has a flat shape. Figures 1 and 2 show an example of such a stator mounting wiring board for a flat motor, where one half 1a of the wiring board 1 is used as a stator mounting area for the motor, and the other half 1b is used for controlling the flat motor. Terminals 4 of the coils 3, 3, ... that constitute the stator 2 are located on the front side of the stator mounting area 1a.
Wiring films 5, 5, . . . to which the coils 4, . . . are connected are formed, and the coils 3, 3, . The terminals 4, 4, . . . of the coils 3, 3, . . . and the wiring films 5, 5, . . . are connected by soldering. Further, on the front side of the flat motor control electronic circuit formation area 1b, various parts 6, 6, ... constituting the flat motor control electronic circuit are attached, as shown in FIG. 2, which is a bottom view of the printed wiring board. As shown, a large number of wiring films 7, 7, . . . , which electrically connect the electronic components 6, 6, .
Note that 8, 8, . . . are holes through which screws for attaching the printed wiring board 1 to a sub-chassis (not shown) are passed. The sub-chassis is equipped with a yoke made of a 1.2mm thick iron plate with bearings. or,
9 is a bearing fitting hole into which a bearing of a yoke (not shown) is fitted.

By the way, after the electronic components 6, 6, ... and coils 3, 3, ... are assembled, the back surface of such a printed wiring board 1 is dip-dipped with solder, or the printed wiring board 1 is coated with a resin coated to harden it. It is sometimes subjected to ultraviolet irradiation treatment and receives heat during that process. Then, there was a problem that the printed wiring board 1 would warp due to the heat. Incidentally, this warpage is specifically such that the central portion of the printed wiring board 1 is curved convexly toward the front side. The occurrence of this warpage may cause contact between the substrate side and the rotor after the flat motor is assembled, which is undesirable. Therefore, if the distance between the substrate side and the rotor is increased because of the fear of such contact, the performance will deteriorate.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide a novel stator mounting wiring board for a motor that reduces warping caused by heat received due to solder dips and the like.

Summary of the Invention In order to achieve the above object, the stator mounting wiring board for a motor of the present invention has a structure in which electronic components constituting an electronic circuit are assembled on a part of the surface, and an electronic circuit is mounted on the back surface of the electronic component assembly portion. A motor stator mounting wiring board on which a conductor film constituting the wiring is formed, and a motor stator is mounted on the other part of the surface, and one or more warp prevention conductors are provided on the back side of the part where the motor stator is mounted. It is characterized by forming a film, and the warp prevention conductor film formed on the back side of the part where the motor stator is attached can effectively prevent the board from warping.

Embodiments Hereinafter, the stator mounting wiring board for a motor of the present invention will be described in detail according to embodiments shown in the accompanying drawings.

FIG. 3 is a bottom view of an example 1-1 of the stator mounting wiring board for a motor according to the present invention. This motor stator mounting wiring board 1-1 is shown in Figures 1 and 2.
The only difference from the one shown in the figure is the shape of the back surface, particularly the shape of the stator attachment area 1a, and the other points are completely the same. Therefore, in describing this embodiment 1-1, a detailed explanation of the common features will be omitted, and only the differences will be explained with reference to FIG. 3 showing the bottom surface with the differences.

In FIG. 3, 10, 10, ..., 11 are conductive films formed on the back surface of the motor stator mounting area 1a of the motor stator mounting wiring board 1,
The wiring films 7, 7, . . . formed on the back surface of the electronic circuit forming area 1b are formed at the same time using the same material, but they are different from the wiring films 7, 7, . have completely different functions. That is, the conductor films 10, 10, . . . , 11 do not constitute an electronic circuit, but are used to prevent the substrate 1-1 from warping. Conductor film 10 for preventing warpage,
10, . . . are formed concentrically with the bearing fitting hole 9 as the center. Therefore, the warpage prevention conductor film 1
0, 10, . . . become concentric circles centered on the rotational axis of the motor after the motor is assembled. The warpage prevention conductor film 11 is formed along the periphery of the stator attachment area 1a. The thickness of this wiring board 1-1 is 1.0 mm, the width W of the stator mounting area 1a is 60 mm,
The length l is also 60 mm.

The motor stator mounting wiring board 1-1 in which such conductor films 10, 10, ..., 11 are provided on the back surface of the stator mounting area 1a has a small amount of warpage, and the conductor films 10, 10, ..., 11 are not warped when the motor rotates. The loss due to the eddy current flowing in 11 is also small. Therefore, this point will be discussed next while comparing with various comparative examples. In addition, FIGS. 4A to C are each comparative example 1.
-2, 1-3, and 1-4.

FIG. 4A shows a comparative example 1- in which a conductor film 12 for preventing warpage is formed entirely on the back surface of the stator mounting area 1a.
2 is shown. In Figure B, a ring-shaped warpage prevention conductor film 13 is formed on the inner edge of the bearing fitting hole 9 on the back side of the stator attachment area 1a, and a warpage prevention conductor film 11 is formed along the peripheral edge of the stator attachment area 1a. , Comparative Example 1-3 is shown in which a large number of warp-preventing conductor films 14, 14, . In addition, FIG. C shows comparative example 1 in which a ring-shaped warpage prevention conductor film 13 is provided on the inner edge of the bearing fitting hole 9, and a warpage prevention conductor film 11 is provided on the peripheral edge of the stator mounting area 1a.
-4. This Comparative Example 1-4 is, so to speak, the same as Comparative Example 1-3 shown in FIG. 4B except that the radially extending conductor films 14, 14, . . . for preventing warpage are removed. Note that FIGS. 4A to 4C only show the back side of the stator mounting area 1a of the printed wiring board 1. Further, the size of the stator mounting area 1a is as shown in FIG.
It is exactly the same as that of 1.

FIG. 5 is a bar graph showing the amount of warpage for Example 1-1 of the present invention and each of the above-mentioned Comparative Examples 1-2 to 1-4, and FIG. 5A shows the amount of reverse warpage before solder dip treatment. Here, the amount of reverse warpage refers to the warpage in which the center portion of the substrate 1 is recessed toward the back side, as shown in the upper part of FIG. That is, in general, the printed wiring board 1 is reversely warped before it is subjected to solder dip treatment or the like. Then, when it is heated by a solder dip treatment or the like, a warpage occurs in which the center part bulges toward the front side (as shown in the upper right part of FIG. 5B). By the way, when comparing the amount of reverse warpage that occurs before processing the solder dip, etc. with the amount of warpage that occurs due to the solder dip processing, etc., the latter is larger, and therefore the printed wiring board 1
Eventually, it is normal for the center to become warped with a bulge. Therefore, before performing solder dip treatment, etc., warpage correction may be applied to the printed wiring board 1 where reverse warpage has occurred to slightly increase the amount of reverse warp, so that the amount of warpage is finally reduced. . FIG. 5A shows an example 1-1 of the implementation of the present invention and comparative examples 1-2 to 1-1.
4 shows the amount of reverse warpage that occurs before the solder dip treatment for those that have not been corrected (indicated by a normal bar) and those that have been corrected (indicated by a hatched bar). It is something. As is clear from this figure, Example 1-1 of the implementation of the present invention shown in FIG. 3 and Comparative Example 1-2 shown in FIG. 4A.
The amount of reverse warpage is relatively large, and the amount of reverse warp is relatively small in Comparative Examples 1-3 and 1-4 shown in FIGS. 4B and 4C.

FIG. 5B shows the amount of warpage after the solder dip treatment for the same examples 1-2 to 1 to 4 as the embodiment of the present invention and each comparative example shown in FIG. 5A. As is clear from this figure, the amount of warpage can be reduced to 0.3 mm or less without warp correction, and the amount of warp can be reduced to 0.2 mm or less with warp correction. Particularly, an example 1 of implementing the claimed invention shown in FIG.
According to Comparative Example 1-1, the amount of warpage can be reduced to less than 0.1 mm regardless of whether or not warp correction is performed, and according to Comparative Example 1-2 shown in Figure 4A, the amount of warpage can be reduced to approximately 0. .

In terms of being able to reduce the amount of warpage, Comparative Example 1-2 in which a conductor film 12 for warping prevention was formed on the entire back side of the stator mounting area 1a as shown in FIG. 4A is the best, and as shown in FIG. It can be said that Example 1-1 of the present invention in which concentric conductor films 10, 10, . . . for preventing warpage are formed as shown in FIG. However, Comparative Example 1-
2 has the aspect that eddy current flows through the conductor film 12 due to the rotation of the flat motor, causing eddy current loss.
Focusing solely on the fact that the amount of warpage is small, the fourth
Comparative Example 1-2 shown in Figure A cannot be immediately determined to be the most preferable.

FIG. 6 shows the current and rotational speed of the flat motor at no load for an example of implementation of the present invention and each comparative example. As is clear from this figure, Example 1-1 of the implementation of the present invention and Comparative Example 1-2
Comparing these, the no-load current in Example 1-1 of the implementation of the present invention is smaller than that of Comparative Example 1-2, and the rotation speed at no-load is lower than that of Example 1-1 of the implementation of the present invention. 1 is larger than Comparative Example 1-2. Therefore, it can be said that Example 1-1 of the present invention shown in FIG. 3 is superior in terms of electrical characteristics.

Incidentally, even when compared with Comparative Example 1-3 shown in FIG. 4B, Example 1-1 of the present invention is superior in that it has a low no-load current and a large number of revolutions under no-load. Moreover, when compared with Comparative Example 1-4 shown in FIG. 4C, there is almost no difference in no-load current;
Regarding the number of revolutions under no load, Example 1-1 of the embodiment of the present invention is significantly superior. Example 1-1 and Comparative Example 1-2 of the present invention shown in FIG.
The remarkable difference in characteristics between the warpage prevention conductor film 10 and
This shows that the eddy current in the motor 12 greatly affects the characteristics of the motor. That is, in Comparative Example 1-2 shown in FIG. 4A, the conductor film 12 is formed on the entire back surface of the stator attachment area 1a, and the loop through which the eddy current flows is formed in the conductor film 12 with almost no restraint. Example 1-1 of implementing the present invention shown in FIG.
Since the conductor films 10, 10, . . . are formed in concentric circles, there is almost no room for forming a path for the eddy current ec to flow as shown by the broken line in FIG. Therefore, the amount of eddy current loss generated should be significantly different from Example 1- of the implementation of the present invention shown in FIG.
It can be said that the difference in characteristics between Comparative Example 1 and Comparative Example 1-2 supports the existence of the difference in eddy current loss. In this way, the conductor film for preventing warpage affects the characteristics of the motor, and while it is important that the warp be small in the motor stator mounting wiring board 1, it is also important to ensure that the electrical characteristics of the motor are as good as possible. Certain things are also required. Comprehensively judging from the above, it can be said that Example 1-1 of the embodiment of the present invention shown in FIG. 3 is the most preferable.

Effects As described above, in the stator mounting wiring board for a motor of the present invention, electronic components constituting an electronic circuit are assembled on a part of the surface, and wiring for the electronic circuit is mounted on the back surface of the electronic component assembly part. A motor stator mounting wiring board on which a motor stator having a plurality of stator coils arranged in a circle on the other part of the surface is attached, on which a conductive film is formed,
It is characterized in that a plurality of warp-preventing conductor films are formed concentrically on the back surface of the part where the motor stator is attached. Therefore, according to the present invention, it is possible to effectively prevent the board from warping by the warp-preventing conductive film formed on the back side of the part to which the motor stator is attached, and as a result, the rotor can be prevented from warping. There is no risk of contact with the sides, and gaps can be further reduced. In other words, it is possible to provide a novel stator mounting wiring board for a motor that has less warpage and can therefore make the gap with the rotor small and uniform.

Moreover, since the plurality of warp-preventing conductor films are formed concentrically, it is possible not only to prevent warpage but also to prevent large eddy current loss from occurring. Therefore, according to the present invention, it is possible to prevent contact between the rotor and the substrate side without degrading the characteristics of the motor.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a stator mounting wiring board for a motor, Fig. 2 is a bottom view showing a conventional example, Fig. 3 is a bottom view showing an example of implementation of the stator mounting wiring board for a motor of the present invention, and Figs. C is a bottom view showing the main parts of each comparative example, FIG. FIG. 6 is a graph showing the amount of warpage afterward, and FIG. 6 is a graph showing the no-load current and the number of rotations at no-load of the motor of an example of the implementation of the present invention and each comparative example. Explanation of symbols, 1-1 to 1-4...Motor stator mounting wiring board, 2...Motor stator, 3
...Stator coil, 10, 11, 12, 13...
...Conductor film for warping prevention.

Claims (1)

[Claims] 1. Electronic components constituting an electronic circuit are assembled on a part of the surface, a conductor film constituting the wiring of the electronic circuit is formed on the back surface of the electronic component assembly part, and a plurality of stator coils are formed on the other part of the surface. A motor stator mounting wiring board to which a motor stator arranged on a single circle is attached, which has a plurality of warp-preventing conductor films formed concentrically on the back surface of the part to which the motor stator is attached. A stator mounting wiring board for a motor, characterized by: