JP2948096B2 - Thin coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin coil.
More specifically, the present invention relates to a thin coil obtained by slicing a rod-shaped conductive thin film roll.

[0002]

2. Description of the Related Art Conventionally, a thin coil obtained by slicing a rod-shaped thin film wound around a conductive thin film causes welding or burrs on a cut surface when sliced using slice abrasive grains. Therefore, short-circuiting (short-circuiting) occurs between layers as it is. Therefore, the burrs and welded portions of the conductor on the slice surface of the thin coil are removed by etching to remove short-circuits (interlayer shorts) between the conductive thin films of the respective layers.

[0003]

However, according to this conventional thin coil, although the burrs and welding of the conductor / conductive thin film on the slice surface are removed, interlayer short-circuit of the conductive thin film is eliminated. An unknown continuity had occurred.

Accordingly, an object of the present invention is to provide a thin coil in which interlayer short-circuit is small and the copper thin film can be prevented from being damaged.

[0005]

In order to achieve the above object, the present inventors have conducted various studies, and as a result, have found that the layers of a conductive thin film which should be insulated by an insulating layer made of an insulating material and an adhesive. Actually came to know that they were electrically conducted by the abrasive grains.

Generally, it is known that a thin coil cut out of a conductive thin film roll by slicing causes an interlayer short-circuit due to burrs or welding of the conductive thin film on the surface of the slice surface. . However, in practice, as shown in FIG. 2, even at a depth deeper than the surface of the slice surface 104, the insulation is broken by the abrasive grains 105 that have penetrated the conductive thin film 103, causing an interlayer short circuit (hereinafter, this phenomenon is referred to as slice damage). And the layer in which this occurs is called a slice damage layer). It was also found that the depth of the damage increased in proportion to the abrasive grain size. Incidentally, reference numeral 102 denotes an insulating layer.

That is, there are two types of interlayer short-circuits: interlayer short-circuits on the surface of the slice surface and interlayer short-circuits due to slice damage caused by bite of slice abrasive grains. Therefore, it has been found that interlayer short-circuiting cannot be completely prevented unless the conductive thin film on the surface of the slice is not completely removed until the slice damage layer is completely removed.

The present invention has been made on the basis of the above findings, and a thin coil obtained by slicing a rod-shaped conductive thin film wound around a conductive thin film provided with an insulating layer, The insulating layer exposed on the slice surface protrudes from the conductive thin film, and the amount of protrusion of the insulating layer is at least conductive.
Of the average grain size of the abrasive grains used for slicing the conductive thin film roll
At least half the height.

Further , the protrusion of the insulating layer of the thin coil of the present invention.
Should be formed by etching the sliced surface.
ing.

[0010]

Therefore, the conductive thin film not only removes burrs and welds on the surface of the slice surface, but also removes abrasive grains that have penetrated. In particular, so as to at least reach about almost half of the average grain size of the abrasive grains used for slicing amount of protrusion of the insulating layer
Since the insulation layer is projected, the slice surface is etched.
In this case, the slice damage layer in which the abrasive grains have penetrated is almost completely removed even with a standardized uniform etching process. Then, conduction by the abrasive grains is removed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of the present invention will be described below in detail with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment of a thin coil according to the present invention. The thin coil 1 has a rod-shaped conductive thin film wound around a conductive thin film 3 having an insulating layer 2 made of an insulating material and an adhesive or an adhesive having an insulating function formed on one surface, and having a predetermined thickness. It is obtained by slicing using abrasive grains . The insulating layer 2 is formed on the slice surface 4 so as to protrude from the conductive thin film 3. Here, the amount of protrusion H of the insulating layer 2, that is, the amount of dent of the conductive thin film 3 from the slice surface 4 is such that at least the slice damage layer damaged by the penetration of abrasive grains can be removed, and more preferably slightly more than the slice damage layer. It is provided to be deeper.

The protrusion of the insulating layer 2 from the conductive thin film 3 is formed, for example, by etching the slice surface. As a guide for the etching treatment, it is preferable to perform the etching to a depth of about half the average particle diameter of the abrasive grains used for slicing. In this case, it was found that the slice damage layer damaged by the penetration of the abrasive grains could be almost completely removed.
Here, since a proportional relationship is established between the etching depth and the etching processing time, if the etching conditions are constant, the etching depth can be made a desired amount by controlling the processing time.

According to the thin coil configured as described above, no abrasive grains remain in the conductive thin film portion deeply etched from the slice surface, and interlayer short-circuit was almost completely eliminated. In addition, the conductive thin film 3 and the insulating layer 2 protruding from between the conductive thin films 3 function as a protection wall for preventing other members from directly contacting the conductive thin film 3.

The above-described embodiment is one of preferred embodiments, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

[0016]

As is clear from the above description, in the thin coil of the present invention, since the insulating layer exposed on the slice surface protrudes from the conductive thin film, not only the burrs and welding of the conductor but also the abrasive The portion that has been entrapped is also completely removed, and the conductive portion due to the abrasive grains is removed, so that it is possible to completely insulate without interlayer short-circuit. Further, since the insulating layer protrudes from the conductive thin film, even if the insulating film is slightly damaged in a later step, the conductive thin film itself is protected from being protected by the protruding insulating layer. Therefore, according to the present invention, the interlayer short-circuit caused by the slicing process is completely removed, so that a thin coil having a high yield can be manufactured. Also, the amount of protrusion of the insulating layer is small.
Average of abrasive grains used for slicing at least conductive thin film roll
The height of the insulating layer is more than half of the particle size.
If the protrusions are formed by etching the sliced surface,
Leveled uniform etching process, for example, etching process
Even if the etching process with a fixed time
The sliced damage layer is completely removed.
This can easily eliminate short-circuit between layers.

[0017]

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing an example of a thin coil of the present invention in the vicinity of a slice plane.

FIG. 2 is an enlarged cross-sectional view showing an example of a conventional thin coil in the vicinity of a slice surface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thin coil 2 Insulating layer 3 Conductive thin film 4 Slice surface H Projection height of insulating layer

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-49-125842 (JP, A) JP-A-3-148812 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01F 27/28 H01F 17/00 H01F 27/32 H01F 41/12

Claims (2)

(57) [Claims] 1. A thin coil obtained by slicing a rod-shaped conductive thin film wound around a conductive thin film provided with an insulating layer using abrasive grains, wherein the insulating layer exposed on the slice surface is Protruding from the conductive thin film , the insulating layer
The protrusion amount is at least used for slicing the conductive thin film roll.
That the height is at least half of the average
Features a thin coil. 2. The method according to claim 1 , wherein the protruding portion of the insulating layer forms the slice surface.
The thin coil according to claim 1, wherein the coil is formed by etching .