JPS59149013A - Manufacture of rotary transformer - Google Patents

Abstract

PURPOSE:To cut down the number of manhours required for manufacture of the titled rotary transformer as well as to contrive accomplishment of miniaturization and improvement in efficiency by a method wherein, after a resist mask has been formed on the region other than the coil pattern part on the surface of a plated base, a coil is formed by performing a conductor plating, and said coil is adhered to the wiring groove of a magnetic core. CONSTITUTION:A resist mask 14 is formed on the surface of the plated base 7 consisting of conductive material excluding a coil pattern part 8', a coil 8 is formed by performing a conductive plating on the coil pattern part 8', and a coil 8 is adhered to the winding groove 3 formed on a magnetic core 1. As a result, the manhours for the manufacture of the rotary transformer can be reduced, its cost can be cut down, and miniaturization and improvement of efficiency of the rotary transformer can also be contrived.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a novel method for manufacturing a rotary transformer.

In detail, this is a new method for manufacturing a rotary transformer that reduces the cost of the rotary transformer by reducing the number of man-hours required to manufacture the rotary transformer, and also reduces the size and improves the performance of the rotary transformer by improving dimensional accuracy. This is what we are trying to provide.

BACKGROUND ART AND PROBLEMS THEREOF For example, in a magnetic recording/reproducing device, a rotary transformer is used to mutually transmit signals between a rotating part and a fixed part.

FIG. 1 shows an example of such a rotary transformer. A pair of annular magnetic cores a, a' are opposed to each other with a minute gap interposed therebetween, and annular winding grooves b' and C1C' are formed on the opposing surfaces of each magnetic core a, a', In each winding groove, b', c, and c', there is a coil d.
, d' and e, e' are inserted. Furthermore, f, f'
is a short ring provided between winding grooves b, b' and c, c'.

The annular magnetic cores a and a' configured as described above are mutually rotatable, and signals are mutually transmitted between the coils d and d' and between the coils e and e'. It is.

By the way, when manufacturing a rotary transformer as described above, conventionally, conductive wires of appropriate wire diameters are wound to form coils d, d', e, and e', and these are placed in winding grooves. '
It was inserted into C and C'. However, the coils d, d', e, and e' are wound to match the diameters and widths of the winding grooves b', c, and c' of the annular magnetic cores a, a',
In addition, fitting the rotary transformer into a predetermined position at a predetermined depth requires extremely precise processing and assembly techniques, and as a result, the cost of the rotary transformer has become extremely high.

Furthermore, when forming the coils d, d', e, and e', the conductors may partially overlap, so the winding grooves b' and C1C' are formed deeper by that amount, taking this into account. This is necessary. For example, the wire diameter of the conductor is 0.15
In the case of mm, the winding groove, b' and C, C' (7) depth is 0.
．． It needs to be 3mm. Then, the distance between the winding grooves B' and C and C' facing each other increases by the above-mentioned extra depth, and there is a problem that the efficiency of direct signal transmission between the coils decreases. In order to compensate for this loss, it is necessary to increase the area where the magnetic cores face each other, which hinders miniaturization.

Purpose of the Invention The present invention was created in view of the problems that existed in the conventional manufacturing method of rotary transformers, and aims to reduce the cost of rotary transformers by reducing the number of man-hours for manufacturing rotary transformers, as well as improve dimensional accuracy. It is an object of the present invention to provide a novel method for manufacturing a rotary transformer that can reduce the size of the rotary transformer and improve its performance by improving the performance of the rotary transformer.

Summary of the Invention The method for manufacturing a rotary transformer of the present invention has been accomplished in order to achieve the above-mentioned object, in which a resist mask is formed on the surface of a plated substrate made of a conductive material excluding the coil pattern portion, and then the coil pattern is The magnetic core is characterized in that a coil is formed by applying conductive plating to the magnetic core, and the coil is bonded within a winding groove formed in the magnetic core.

EXAMPLES Below, the details of the method for manufacturing the rotary transformer of the present invention will be explained according to the illustrated examples.

Embodiment 1 The 0-Tali transformer includes a pair of magnetic cores, but their shapes are substantially the same, and therefore the manufacturing procedure is also the same, so only the magnetic core of 0- will be described.

In the figure, 1 is an annular ferrite core, and two winding grooves 2 and 3 are formed in an annular shape on one surface, and a separation groove 4 is formed at a position between the winding grooves 2 and 3. is formed. Reference numerals 5 and 6 are coil lead extraction holes formed close to the winding grooves 2 and 3, respectively.

7 is a plated base made of a conductive material such as stainless steel, and two coils 8.7 are provided on the surface of the plated base 7.
A coil 8.9 and a short ring 10 are formed by plating, and the coil 8.9 and short ring 10 formed by these plating are adhesively transferred into the respective grooves 2.3 and 4 of the ferrite core 1. In addition, in the plating process, each coil 8
．． Lead wires 11.11 and 12.12 of 9 are also formed together, and before the above-mentioned adhesion process, they are raised from the plating base 7 in advance and then inserted into the extraction holes 5.6.

Next, the manufacturing procedure will be explained in more detail with reference to FIG. In addition, in FIG. 5, ferrite core l, coil 8,
A part of the plating base 7 etc. is shown in an enlarged manner.

A photosensitive resist film 13 is attached to the entire surface of the plating substrate 7 (see FIG. 5(A)). At this time, before applying the photosensitive resist film 13, the entire surface of the plating base 7 may be subjected to a treatment to facilitate peeling off of the plating, such as chrome plating. It should be noted that it is preferable to use the photosensitive resist film 13 to form the resist mask because the film thickness of the resist mask can be made uniform and a relatively thick film can be obtained. It is not necessary to use the same type of photoresist agent, and other types of photosensitive resist agents may be used.

Next, the photosensitive resist film 13 is exposed and developed,
The photosensitive resist film 13 at the locations where the coil 8.9 and the short ring 10 are to be formed is removed to form a so-called resist mask 14 (see FIG. 5(B)). The areas to be exposed to light differ depending on whether the photosensitive resist film 13 is a negative type or a positive type. The areas where this happens are exposed to light.

Conductor plating, for example copper plating, is applied to the plating base 7 on which the resist mask 14 is formed as described above. As a means for applying plating, for example, the plating base 7 is made into a cathode and the pattern parts 8', 9', 10' are formed by electroplating.
(Only 8' is shown.) Copper is deposited on it. In this way, a conductor such as copper is deposited on the pattern parts 8', 9', and 10' drawn by the resist mask 14, and a coil 8.9 and a short ring 10 are formed on the plating base 7 ( (See Figure 5(C)).

Apply an appropriate amount of adhesive 1 to the winding groove 2.3 and separation groove 4 (only the winding groove 2 is shown in FIG. 5) of the ferrite core l.
5 (see Figure 5(D)).

Then each coil 8.9 formed on the plated substrate 7
and the short ring 10 in each groove 2 of the ferrite core 1,
Insert while aligning 3 and 4. Then, each coil 8.9 and short ring 10 are adhesively fixed to the ferrite core 1 by the adhesive 15 applied in each groove 2.3 and 4 (see FIG. 5(E)).

In this case, the resist mask 14 is removed from the plating base 7.
be removed in advance, or the resist mask 14
It may be arbitrarily selected whether to leave it as an insulating layer and to transfer it to the ferrite core 1 together with the coil etc.

Finally, the coil 8.9 and short ring 10 are securely bonded and fixed in the winding groove 2.3 and separation groove 4 of the ferrite core 1.

When the plating base 7 is removed, the coil 8.9 and the short ring 10 are peeled off from the plating base 7 (see Fig. 5 (F)).
)reference).

As explained below, according to the method of the present invention, since the coil 8.9 is formed by plating means, its dimensional accuracy is extremely good, manufacturing variations are eliminated, and the ferrite core l The alignment with each groove 2.3 is also achieved with extremely high precision. Therefore, coil 8.9
The dimensional relationship between the coil 8.9 and the winding groove 2.3 can also be precisely defined in advance, so that the coil 8.9 and the plane of the ferrite core 1 are aligned (see Fig. 5 (E) and CF). ), therefore, the efficiency of signal transmission in the coil section can be improved, and this makes it possible to reduce the facing area between a pair of ferrite cores, making it possible to reduce the size of the rotary transformer. This will contribute to the

In addition, since the coils 8 and 9 are formed by plating, not only is the coil forming process extremely easy, but even if there are multiple coils, the forming process is hardly increased, so it is possible to manufacture a multi-channel rotary transformer. This has the advantage that the effect of cost reduction is significantly greater.

Embodiment 2 Although the above embodiment has been explained by taking as an example the manufacture of a rotary transformer using a disk-shaped magnetic core, the method of the present invention can also be applied to the manufacture of a cylindrical rotary transformer.

In particular, winding a coil around the inner circumferential surface of a cylindrical magnetic core was previously considered to be an extremely difficult task, but according to the present invention, a cylindrical rotary j-lance can be manufactured extremely easily. can.

16 is an annular ferrite core, and an annular notched recess 17 is formed on the inner peripheral edge of the upper surface thereof. The coil 18 formed using the plating means as described above is adhesively fixed in the cutout recess 17 of the ferrite core 16 by the procedure shown in FIG. 5 described above.

Reference numeral 19 designates a ferrite core which is also annular and has an annular notched recess 20 formed on the inner periphery of its upper surface, into which a coil 21 formed by plating means is adhesively fixed.

Therefore, if the ferrite core 19 is superimposed on the ferrite core 16 formed in this way and fixed to each other by adhesive or the like, and then the annular ferrite plate 22 of the same shape is superposed and fixed on top of the ferrite core 19, A cylindrical rotary transformer member is formed with a coil 18.21 attached to its inner peripheral surface.

Although not shown in the drawings, the rotary transformer member paired with this cylindrical rotary transformer member has a coil paired with the coils 18 and 21 formed on the outer peripheral surface of the cylindrical body, so that the outer peripheral edge of the upper surface It can be formed by laminating and bonding a coil having a cutout recess in the cutout recess, and a coil formed by plating means being adhesively fixed in the cutout recess.

As described above, according to the method for manufacturing a rotary transformer of the present invention, a cylindrical rotary transformer can be manufactured very easily and at low cost, and it is also possible to manufacture a cylindrical rotary transformer with good precision and high efficiency. can.

Effects of the Invention As is clear from the above description, the method for manufacturing the rotary transformer of the present invention involves forming a resist mask on the surface of a plated substrate made of a conductive material, excluding the coil pattern portion, and then applying a conductor to the coil pattern portion. It is characterized in that a coil is formed by plating, and the coil is adhered within a winding groove formed in a magnetic core.

Therefore, according to the present invention, it is possible to reduce the cost of the rotary transformer by reducing the number of man-hours required for manufacturing the rotary transformer, and also to reduce the size and improve the performance of the rotary transformer by improving the dimensional accuracy. A method for manufacturing a rotary transformer can be provided.

1. In the description of the above embodiments, a ferrite core is used as the magnetic core, but the present invention is not limited to this, and it goes without saying that other suitable magnetic core materials can be used.

[Brief explanation of drawings]

Fig. 1 and Fig. 2 show an example of a conventional rotary transformer, Fig. 1 is a longitudinal sectional view, Fig. 2 is a partially enlarged view of Fig. 1,
FIG. 3 is a perspective view showing an example of a magnetic core used in the present invention;
Figure 4 is a perspective view of a state in which a coil is formed on a plated base;
FIG. 5 is a partially enlarged sectional view showing an example of the method for manufacturing a rotary transformer of the present invention, and FIGS. 6 and 7 show another example of a rotary transformer manufactured by the method of the present invention.
The figure is an exploded perspective view, and FIG. 7 is a longitudinal sectional view. Explanation of symbols 1... Φ magnetic core, 2. @Φ winding groove, 3. wire winding groove, 7... plating base, 8'... coil pattern, 8. fist coil, 9. number・Coil, 14...Resist mask, 2 16φ..., Magnetic core, 17 coils, 9 winding grooves, 18◆
as coil, 19-・-m%: 17.20φΦ wire winding groove, 21...Coil Fig. 6 Off view

Claims (1)

[Claims] (1) A resist mask is formed on the surface of a plating base made of a conductive material, excluding the coil pattern portion, and then conductor plating is applied to the coil pattern portion to form a coil, and the coil is wound around a magnetic core. A method for manufacturing a rotary transformer characterized by adhesive bonding within the groove