JPH03148102A - Rotatable transformer and manufacture thereof - Google Patents

Abstract

PURPOSE:To enable an easy formation of coils of high channel density by providing slits formed radially on the surfaces of magnetic cores which face one another with an air gap between them, leads laid in the slits, and conductors connecting leads together. CONSTITUTION:Slits 6, 7 are formed radially on magnetic cores 10, 11. Leads 16, 17 are laid in the formed slits 6, 7 and are connected together by conductors. Terminal parts 18-21 of coils are provided on at least one of the inner and outer circumference of the surfaces of a rotor side and a stator side element 1, 2 which are opposed each other, and obliquely cut tip parts of the terminal parts of the coils are connected with the terminals to be connected. When a signal current flows through a coil 14 of the rotor side element 1, a closed magnetic path is formed by the magnetic cores 10, 11 which face each other with an air gap 3 between them and a current is induced through a coil 15 of the stator side by the action of mutual induction to transmit the signal. Also, inversely, when the signal current flows through the coil 15 of the stator side element 2 the signal is transmitted through the coil 14 of the rotor side element 1 similarly. Thereby, a rotatable transformer having the channel number of high density can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary transformer which is a means for transmitting signals between a rotary head of a rotary magnetic recording and reproducing apparatus for transmitting video signals and the like and an electronic circuit such as an amplifier, and a method for manufacturing the same.

Conventional technology In recent years, with the increasing density and transfer rate of recording and reproducing devices due to the digitization of equipment, the field of magnetic recording technology has progressed toward narrower tracks, multi-tracks, and wider bands. In playback devices as well, rotary transformers, which serve as signal transmission means between rotary heads and electronic circuits such as amplifiers, are becoming multi-channeled, resulting in higher density, wider bandwidth, and smaller size.

A conventional rotary transformer will be described below with reference to the drawings.

FIG. 6 shows a cross-sectional view including the diameter of a conventional rotary transformer having two channels. 6th
In the figure, 41 is a rotating element, 42 is a stationary element, and 43
44.4 is the gap separating the main bodies on the rotating side and the stationary side, 44.4
5 are non-magnetic substrates facing each other with a gap in between, 46.47 are grooves formed on the opposing surfaces of each substrate corresponding to the channels on the rotating side and the stationary side, 48.49 are the first insulating layers, and 50° 5
1 is a magnetic core provided in these grooves, and 52.
53 is a wire-shaped coil formed in the groove of the magnetic core, 54.55 is a through hole penetrating the substrate, 56.5
7 is an insulating layer formed on the back surface of each substrate with respect to the opposing surface;
58.59 is a coil terminal portion, and 60.61 is a terminal connection portion.

In the rotary transformer configured in this way, when a signal current flows through the coil 52 of the rotating element 41, the gap 43
A closed magnetic path is formed by the magnetic bodies 4849 facing each other via the magnetic bodies 4849, and a current is induced in the fixed side coil 53 due to mutual induction, and a signal is transmitted. On the other hand, the fixed side element 4
When a signal current flows through the second coil 53, the signal is similarly transmitted to the coil 52 of the rotating element.

Problems to be Solved by the Invention However, in the above configuration, since the magnetic core is axially symmetrical, when the frequency of the signal increases, eddy currents are generated in the circumferential direction within the magnetic body.

In general, the magnitude of eddy current increases as the magnetic flux that interlinks with the closed loop in which the eddy current flows increases, so in an axisymmetric configuration such as the one above, the influence of eddy current increases, and the magnetic flux due to eddy current flows inside the magnetic body. The transmission characteristics at high frequencies deteriorate as the magnetic flux involved in transmission decreases.

In addition, if a through hole is passed through the board and the coil lead is wired through the hole, it cannot be used because there is a high possibility that the conductor formed by film formation will break. Because of the space required, it has been difficult to increase the number of channels and narrow the pitch.

In view of the above-mentioned problems, an object of the present invention is to provide a rotary transformer having excellent signal transmission characteristics at high frequencies and a high density of channels, and a method for manufacturing the same.

Means for Solving the Problems In order to solve the above problems, the rotating I/lance of the present invention has the following features:
Slits are formed radially in the magnetic core, leads are arranged in the formed slits, and the leads are connected by a conductor. The coil terminal portion is provided on at least one of the inner circumferential portion and the outer circumferential portion on the opposing surfaces of the rotating side element and the stationary side element, and the terminal to be connected to the tip portion of the coil terminal portion cut off diagonally is connected. That is.

Effect In the present invention, by having the above configuration, in a rotary transformer having multiple channels, the eddy current generated in the circumferential direction inside the magnetic body is cut off because the slit is provided in the magnetic core. It becomes less likely to occur. In addition, since there are many radially formed slits, the eddy current loop becomes smaller, so there is less magnetic flux interlinking with the loop (
Therefore, the influence of eddy currents can be reduced.

The leads that are separated at the point where they intersect with the coil of another channel are connected to the conductor formed in the underlying layer through the insulating layer and through the through hole. Therefore, the signal current transmitted from the external terminal by the coil terminal on the outer periphery flows to the coil via the lead and the conductor, and then from the coil terminal on the inner periphery to the other external terminal via the lead and conductor. transmitted to. The same applies to the opposite case.

In addition, by providing the coil terminal part on at least one of the inner and outer peripheral parts on the opposing surfaces of the rotating element and the stationary element, and cutting it off diagonally, it is possible to connect it to an external terminal by soldering, etc. It becomes easy to connect the coils and leads formed by film formation to external terminals.

EXAMPLE Hereinafter, as an example of the present invention, a rotary transformer having two channels and having two slits provided in the magnetic core will be described with reference to the drawings.

FIG. 1 is a sectional view of a rotary transformer according to an embodiment of the present invention, and FIG.
Figure (a) is a plan view of the rotating element, and Figure 2 (a) is a plan view of the rotating element.
) AA = cross-sectional view, Fig. 3 (a) and P in Fig. 2 (a)
FIG. 3(b) is an enlarged plan view of section Q in FIG. 2(a), FIG. 3(C) is an enlarged plan view of section Q in FIG. ) is a BB cross-sectional view of FIG. 3(C).

In Figure 1, there are 1.2 channels from the inside, 1 is the rotating side element of the rotating transformer, 2 is the fixed side element of the rotating transformer, and 3 is between the opposing surfaces of the rotating side and fixed side for the 1.2 channels of the rotating transformer. Gap parts 4 and 5 are non-magnetic substrates on the rotating side and stationary side of the rotary transformer, 6:7 is a groove formed on the opposing surface of each substrate corresponding to a slit for arranging a lead and each channel, 8, 9B first insulating layer, 10.1
1 is a magnetic core, 12.13 is a second insulating layer, 14°1
Reference numeral 5 denotes a coil formed in a groove in the magnetic core, which is generated in imitation of the channel groove of the nonmagnetic substrate. In Fig. 2, which shows the opposing surface of the rotating side element, 16 is a 1-channel lead, 17 is a 2-channel lead, and 18.19 is a 1-channel lead.
Coil terminal portions disposed on the inner circumferential portion and outer circumferential portion of the opposing surfaces of the two channels, 20° and 21 are coil terminal portions disposed on the inner circumferential portion and the outer circumferential portion of the opposing surfaces of the two channels. Furthermore, Figure 3 (
a) is the part where the coil arranged in the groove and the lead of the same channel as the coil arranged in the groove are connected, (
C) is a part where the lead is separated by a coil in another channel, and in (d), 22 is a conductor, 23 is a through hole formed in the second insulating layer, and in another channel The leads separated at the coil portion are connected via a conductor and connected to the coil terminal portion.

Note that the fixed side element also has the same structure as the rotating side element described above.

In the rotary transformer configured in this way, when a signal current flows through the coil 14 of the rotating element, a closed magnetic path is formed by the magnetic bodies 10 and 11 facing each other through the air gap 3, and the magnetic bodies are fixed by mutual induction. A current is induced in the side coil 15 and a signal is transmitted. Conversely, when a signal current flows through the coil 15 of the fixed element, the signal is similarly transmitted to the coil 14 of the rotating element.

Here, the non-magnetic substrate is a conductor substrate with high conductivity such as aluminum, a ceramic substrate, a substrate such as crystallized glass, and a conductor such as copper or aluminum formed in a thickness of several tens to hundreds of micrometers on the opposite side of the substrate. The magnetic material is Fe-C
Soft magnetic materials with high permeability such as o-Ni, permalloy, sendust, CO-based amorphous, etc., and conductive materials with high dielectric constants such as copper and aluminum are plated for the coil, lead, coil terminal, and conductor. It is formed by vapor deposition or the like.

Further, the number of channels is not limited to two channels.

A method of manufacturing the rotary transformer configured as described above will be described below with reference to FIGS. 4(a) to 4(f) and FIG. 5.

Here, Fig. 4(a) to (C1 is BB- in Fig. 2(a)
The cross sections of FIGS. 4(d) to 4(f) are taken along line AA in FIG. 2(a), and FIG. 5 is an enlarged view of the coil terminal portion.

As shown in FIGS. 4(a) and 4(d), grooves 6 corresponding to slits and channels are formed all at once on the opposing surface of the non-magnetic substrate 4 by machining, etc., with the groove side surfaces inclined with respect to the substrate surface. Then, a first insulating layer 8 is formed. When forming the groove on the board, the coil terminal groove 24 is cut out diagonally at an angle θ such that 206≦θ≦70° with respect to the substrate. form. Then, as shown in FIGS. 4(b) and 4(e), a soft magnetic material with high magnetic permeability such as permalloy or Fe-Co-Ni is plated onto the magnetic core 1 in concentric circles excluding the slit portion of the groove 6. 9 is formed corresponding to each channel. Then, copper, aluminum, or the like is formed in the slit portion of the groove 6 by coating, vapor deposition, or the like, and a second insulating layer is formed. Thereafter, as shown in FIGS. 4(C) and 4(f), place the coil 14 in the groove of the magnetic core with one channel glue layer 16.
Then, the two-channel glue layer 17 is formed in the slit portion of the groove 6, and the coil terminal portion 18 is formed in the coil terminal groove 24 by plating or vapor depositing copper, aluminum, etc., respectively. Finally, planarization is performed to polish the second insulating layer on the magnetic core 9, and external terminals are connected to the coil terminal portions.

The other element is also produced in the same manner as above, and the rotating transformer is completed by making them face each other with the gap 3 interposed therebetween.

Further, the number of channels is not limited to two, and even if the number of channels increases, the number of production steps does not increase.

Furthermore, when forming the conductor or lead, the conductor may also be formed between the channels of the magnetic core at the same time.

Effects of the Invention As described above, the present invention has a structure in which the generation of eddy current is suppressed by the slits formed radially by dividing the magnetic core, and the coil leads are arranged in the slits formed. Because of this, wire breaks are less likely to occur, each channel can be easily narrowed, and the manufacturing process is simplified because the coil and lead can be manufactured in the same process.

Further, the divided leads are connected to the conductor formed below through the insulating layer through the through holes, so that a dense coil can be easily formed.

Also, connect the coil terminals to the rotating side element and the opposite side of the stationary side element.
Since the terminal is provided on at least one of the inner circumference and the outer circumference of the coil terminal and is connected to the diagonally cut off tip of the coil terminal, it can be connected to a membrane-shaped coil without disconnection. Furthermore, there is no need for through balls that pass through the board to wire the coil leads, and furthermore, there is no increase in the manufacturing process even with further multi-channeling, making it easy to increase the number of channels and narrow the pitch. It is effective.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a rotating transformer according to an embodiment of the present invention, FIG. 2(a) is a plan view of a rotating element, and FIG. Figure 3 (a) is the same as Figure 2 (a)
(An enlarged plan view of the DP section, Fig. 3(b) is B in Fig. 3(a))
3(C) is an enlarged plan view of section Q in FIG. 2(a), FIG. 3(d) is a sectional view of section B in FIG.
Figures (a) to (C) are BB = sectional views in Figure 2 (a), Figures 4 (d) to (f) are AA = sectional views in Figure 2 (a), and Figure 5 (a). is an enlarged view of the coil terminal groove, (b)
6 is an enlarged view of a coil terminal portion, and FIG. 6 is a sectional view of a conventional rotating I-lance. DESCRIPTION OF SYMBOLS 1...Rotating side element, 2...Stationing side element, 3...Gap part, 4, 5...Nonmagnetic substrate, 6,7... ... Grooves formed on the substrate, 8, 9.
...First insulating layer, 1011... Magnetic core, 12.13... Second insulating layer, 14.1
5... Coil, 16.17... Lid,
18, 19, 20.2+... Coil terminal section, 2
2... Conductor conductor, 23... Through hole, 24... Coil terminal groove.

Claims (7)

[Claims] (1) A magnetically coupled rotating side element and fixed side element having multiple channels, and a gap between the opposing surfaces of the rotating side element and the fixed side element facing each other, and the rotating side element and the fixed side element Each of the side elements is a rotary transformer including a non-magnetic substrate, a magnetic core, and a coil, and includes grooves formed radially on a surface facing the gap of the magnetic core, and the grooves. 1. A rotary transformer comprising leads disposed within the transformer and a conductor connecting the leads. (2) The rotary transformer according to claim 1, wherein the coil and the conductor are formed by vapor deposition, plating, sputtering, printing, or the like. (3) The rotating transformer according to claim 1, wherein the magnetic core has a laminated structure of a magnetic layer and an insulating layer. (4) A magnetically coupled rotating element and a stationary element having multiple channels, and a gap between opposing surfaces of the rotating element and the stationary element, and a space between the rotating element and the stationary element. A method for manufacturing a rotary transformer each comprising a non-magnetic substrate, a magnetic core, and a coil, the method comprising forming concentric and radial grooves on the substrate, and forming a magnetic core. a step of forming a conductor, a step of forming an insulating layer, a step of forming a through hole in the insulating layer, a step of collectively forming at least a portion of the coil and the lead, and polishing the opposing surface. A method of manufacturing a rotary transformer, comprising the steps of: (5) A magnetically coupled rotating element and a stationary element having multiple channels, and a gap between opposing surfaces of the rotating element and the stationary element; Each of the rotary transformers includes a non-magnetic substrate, a magnetic core, and a coil, and an inner peripheral portion on a surface facing a gap between each of the rotating element and the stationary element. A rotary transformer comprising: a coil terminal portion disposed on at least one of the outer peripheral portions. (6) A magnetically coupled rotating element and a stationary element having multiple channels, and a gap between opposing surfaces of the rotating element and the stationary element; A method for manufacturing a rotating transformer each comprising a non-magnetic substrate, a magnetic core, and a coil, wherein at least a portion of an inner circumferential portion or an outer circumferential portion on the conductor layer is made oblique to the substrate. A method for manufacturing a rotary transformer, comprising the steps of cutting out a coil, forming at least a portion of a coil and a lead, and a coil electrode all at once, and connecting a connecting conductor to the cut out portion. (7) The angle θ of cutting diagonally to the board is 20°≦θ
7. The method of manufacturing a rotary transformer according to claim 6, wherein the angle is ≦70°.