JPH06208924A - Coil and manufacture thereof - Google Patents

Abstract

PURPOSE:To manufacture a non-winding type coil suitable for high frequency circuit and having stabilized inductance and Q value with high productivity. CONSTITUTION:A film-like insulator 2 having a through hole 2c at one end part of conductor pattern is wound around a base body 1 and a conductor pattern at lower position is conducted by means of a conductive adhesive 4 with same conductor pattern at upper position through the through hole thus forming a spiral coil pattern 3. External electrodes 5 to be connected with the coil pattern 3 are provided at the opposite ends of the base body 1 so that the conductor pattern can be conducted between upper and lower positions thereof while simultaneously the film-like insulator 2 can be bonded to another film-like insulator and the conductor pattern thus allowing formation of a plurality of layers of coil pattern 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil particularly suitable for a high frequency circuit and a manufacturing method thereof.

[0002]

2. Description of the Related Art Generally, a coil used as an inductance component in various electric circuits is constructed by winding an insulating coated copper wire around a core made of ferrite or the like. There is a growing demand for low-inductance coils having good characteristics as a type of coil.

Conventionally, in order to obtain this type of coil, a method of reducing the number of windings of the winding wire has been used, but as another method, a coil not using the winding wire has been considered.

For example, an open utility model (Sho 54-31156)
No.) publication, a flexible printed board provided with a conductor pattern having a desired width and a desired pitch is bent into a hollow cylindrical shape,
A high-frequency coil is disclosed in which the flexible printed board and the end portions of the conductor pattern are respectively connected.

[0005]

However, these conventional ones form a coil by printing, or a conductive film formed by a method such as plating is processed into a spiral shape by a cutter or the like to form a coil. Therefore, although it is possible to easily manufacture a coil having a low inductance, it is difficult to obtain sufficiently satisfactory characteristics, and when the base body is cylindrical, the coil can be formed relatively easily, but the base body has a prismatic shape. However, there were problems such as the difficulty in forming it.

Further, in the case where a flexible printed board provided with a conductor pattern is bent into a hollow cylindrical shape and the ends of the flexible printed board and the conductor pattern are soldered to each other, a coil of low inductance can be easily manufactured by single layer winding. However, there is a problem that it is not possible to obtain sufficiently satisfactory characteristics in the multi-layer winding.

An object of the present invention is to solve such problems and to provide a coil which can obtain a stable inductance and a Q value, and a manufacturing method with high productivity.

[0008]

To achieve this object, a coil of the present invention is a film in which a plurality of independent parallel linear conductor patterns are formed and a through hole is formed at one end of the conductor pattern. The conductor-like insulator is wound around the outer peripheral surface of the base body, and the conductor pattern end portion at the lower position and the same conductor pattern at the upper position are conducted with a conductive adhesive through the through holes to form a spiral coil pattern by the conductor pattern. The external electrodes connected to the coil pattern are provided at both ends of the base.

[0009]

With this configuration, it becomes possible to bond the conductor patterns at the lower position and the upper position and to bond the film-shaped insulators and the film-shaped insulator and the conductor patterns at the same time.
Stable inductance and Q value are obtained, and a plurality of layers of coil patterns can be formed by forming conductor patterns at a predetermined pitch in the winding direction of the film-shaped insulator.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 shows a coil according to an embodiment of the present invention, and FIGS. 2 to 9 show a manufacturing process of a coil manufacturing method according to a first embodiment of the present invention.

In FIG. 1, 1 is a prismatic alumina substrate as a base, 2 is a film-like insulator, 3 is a coil pattern, 4 is a conductive adhesive, and 5 is an external electrode.

2 to 9, 2a is a copper layer,
Reference numeral 2b is a conductor pattern formed by etching, 2c is a through hole, 6 is an etching resist, 7 is a photosensitive solder resist, 8 is an element, 9 is an exposure device, and 10 is a dispenser for applying an adhesive.

The operation of the method of manufacturing the coil configured as described above will be described with reference to FIGS.

First, as shown in FIG. 2, copper foil is laminated on the film-like insulator 2 with an adhesive, or a copper layer 2a is formed on the surface of the film-like insulator 2 by means such as vapor deposition or plating. After that, the through hole 2c is formed by laser processing or the like. Next, a photosensitive etching resist is applied / formed on the copper layer 2a formed as shown in FIG. 3, exposed and developed under predetermined conditions to form an etching resist 6 on the copper layer.

Next, using an acidic etching solution such as cupric chloride or ferric chloride, the exposed copper layer 2a in the portion where the etching resist 6 is not formed is etched and removed by a method such as a spray method or a dipping method. Then, the etching resist 6 is stripped and removed with a predetermined stripping solution to form a conductor pattern 2b composed of the copper layer 2a on the film-shaped insulator 2 as shown in FIGS. 4 (a) and 4 (b).

Next, the 96% alumina substrate 1 fired into a prismatic shape as shown in FIG. 5 is chemically etched with a predetermined pretreatment liquid to form fine irregularities in the crystal grain boundaries and in the grains of the ceramic polycrystal. Then, the alumina substrate 1 is prepared by degreasing and cleaning.

Next, the through hole 2c and the conductor pattern 2b.
The film-like insulator 2 having the film formed thereon is set at a predetermined position of the prepared alumina substrate 1, rotation / winding is started as shown in FIG.
As shown in FIG. 4, the conductive adhesive 4 supplied from the nozzle tip of the adhesive application dispenser 10 is applied to the end portion of the lower conductor pattern 2b through the through hole 2c formed in the same conductor pattern 2b and cured. , The coil pattern 3 is formed. These are repeated when forming the coil pattern 3 of multiple layers.

After forming a predetermined number of layers of the coil pattern 3 on the alumina substrate 1, a liquid photosensitive solder resist 7 is applied by dipping or the like on the surface of the alumina substrate 1 on which the coil pattern 3 has been formed, dried by touching and formed. Then, the alumina substrate 1 is repeatedly rotated and stopped by the exposure device 9, and the surface including the coil pattern 3 other than the portion connected to the external electrode 5 is exposed to ultraviolet rays as shown in FIG. An insulating layer of 7 is formed.

Further, after-curing is performed under the conditions of a temperature of 80 to 100 ° C. and a time of about 50 minutes, it is divided into a predetermined size by a diamond cutter or the like to obtain individual pieces 8 as shown in FIG. Caps as external electrodes 5 as shown in FIG. 9 are attached to both ends of the elemental piece 8 and connected to the exposed coil pattern 3 to obtain a finished product.

As described above, according to this embodiment, the film-like insulator having the through hole formed at the one end of the conductor pattern is wound around the outer peripheral surface of the base body, and the conductor pattern end at the lower position and the conductor pattern end at the upper position are provided. By adhering and conducting the same conductor pattern with a conductive adhesive through the through-hole, it is possible to simultaneously conduct the conductor pattern and to bond between the film-like insulators and between the film-like insulator and the conductor pattern. A plurality of layers of coil patterns can be formed by forming the conductor patterns at a predetermined pitch in the body winding direction.

In the embodiment, the copper layer 2a is formed by
Copper foil was laminated on the film-like insulator 2 with an adhesive, or a means such as vapor deposition or plating was used. The film-like insulator 2 and the copper layer 2a are formed by using copper foil as a liquid insulating material. The conductor pattern 2b may be formed of a copper layer 2a, but the conductor pattern 2b may be formed of a metal layer of aluminum, nickel, gold or the like. Further, although the base body is the alumina substrate 1, the base body 1 may be ferrite or the like, and the shape thereof is a prismatic shape, but may be one fired in a cylindrical shape.
Furthermore, although the external electrode 5 is a cap, it goes without saying that it may be formed by solder immersion or solder plating.

[0022]

As described above, according to the present invention, a plurality of independent parallel linear conductor patterns are formed, and a film-like insulator having a through hole at one end of the conductor pattern is formed on the outer peripheral surface of the substrate. After winding, the conductor pattern end part at the lower position and the same conductor pattern at the upper position are bonded and conducted with a conductive adhesive through the through hole to form a spiral coil pattern by the conductor pattern and connected to the coil pattern. By providing external electrodes at both ends of the base, it is possible to easily form a coil pattern of a plurality of layers on a prismatic base, and it is possible to obtain a coil having excellent productivity and stable inductance and Q value. it can.

[Brief description of drawings]

FIG. 1 is a perspective view showing a coil according to an embodiment of the present invention with a part thereof cut away.

FIG. 2 is a sectional view showing a manufacturing process of a coil manufacturing method according to an embodiment of the present invention.

FIG. 3 is a sectional view showing the same manufacturing process.

4A and 4B are sectional views and plan views showing the same manufacturing process.

FIG. 5 is a perspective view showing the same manufacturing process.

6 (a) and 6 (b) are perspective views showing the same manufacturing process and a perspective view with a part cut away.

FIG. 7 is a side view showing the same manufacturing process.

FIG. 8 is a side view showing the same manufacturing process.

FIG. 9 is a perspective view showing the same manufacturing process.

[Explanation of symbols]

 1 Alumina Substrate 2 as Base Material 2 Film Insulator 2a Copper Layer 2b Conductor Pattern 2c Through Hole 3 Coil Pattern 4 Conductive Adhesive 5 External Electrode 6 Etching Resist 7 Photosensitive Solder Resist 8 Element 9 Exposure Device 10 Dispenser

Claims (3)

[Claims] 1. A film-shaped insulator, in which a plurality of independent parallel linear conductor patterns are formed, and a through hole is formed at one end of the conductor pattern, is wound around the outer peripheral surface of the base body, and the conductor pattern end at the lower position is formed. Part and the same conductor pattern at the upper position are bonded and conducted by a conductive adhesive through the through holes to form a spiral coil pattern by the conductor pattern, and the external electrodes connected to the coil pattern are connected to both ends of the substrate. Coil installed in. 2. A step of forming a copper layer on a film-like insulator, a step of forming a photosensitive etching resist on this copper layer and forming an etching resist by exposing with a predetermined pattern, and the etching resist. By etching the copper layer by, a step of forming a plurality of independent parallel linear conductor pattern, a step of forming a through hole in one side end portion of the conductor pattern, winding the film-shaped insulator around the outer peripheral surface of the substrate, A method for manufacturing a coil, comprising a step of applying a conductive adhesive to the end portion of the conductor pattern at a lower position and the same conductor pattern at an upper position through a through hole to form a spiral coil pattern of the conductor pattern. . 3. A plurality of conductor patterns are formed on a long film-like insulator, which is wound around a long base body to form a plurality of coil patterns, and then the base body is cut between the coil patterns. A method for manufacturing the described coil.