JPH07142254A - Printed coil and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a coil pattern having a required thickness in a simple process by a method wherein the coil pattern is formed on an insulating board by a printing and wiring technique, an electroplating layer by an electroplating operation is formed on the coil pattern and a conductor for the coil pattern is reinforced. CONSTITUTION:A plurality of coil patterns 2 which are arranged in the longitudinal direction and the transverse direction on a board surface and connecting patterns 5 which connect the individual coil patterns are formed on an insulating board 1 by a printing and wiring technique. An electroplating operation is performed in such a way that the individual coil patterns 2 constitute an electrode circuit on one side via the connecting patterns 5, plated layers are formed respectively on conductor surfaces of the plurality of coil patterns, and conductors for the individual coil patterns are reinforced. In a coil board which is composed of the plurality of coil patterns 2 whose conductors have been reinforced via a plating process, parts for the connecting patterns 5 are removed. The parts for the connecting patterns 5 are removed by an etching operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed coil which can be widely used in various electric products such as industrial equipment and consumer equipment, and a method for manufacturing the printed coil. The present invention relates to a printed coil in which a conductor is reinforced by plating and a coil pattern having a required conductor thickness can be obtained by a simple process, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Coil and various power transformers formed by coupling several coils are widely used in all fields, regardless of industrial equipment or consumer equipment. When constructing a transformer, signal insulation performance and reliability are emphasized as basic performance, and therefore, a structure in which a coil is constructed by a printed wiring technique and a manufacturing method thereof have been proposed in the past (for example, Japanese Patent Laid-Open No. Sho 61-187). 58-155711, JP-A-60-245208, and JP-A-3-28340.
No. 4, etc.).

Such a transformer has a coil pattern formed on an insulating substrate by a printed wiring technique and has a constant quality compared with a conventional coil formed by winding a conductor wire or a conductor foil, and a large amount. It has many advantages such as being suitable for production.

[0004]

However, in the method of forming a coil pattern by the printed wiring technique, a conductor layer (foil) is first formed on an insulating substrate and then a necessary pattern is obtained by etching. Since it is difficult to increase the height, it is not suitable for forming a coil that handles a large current.

On the other hand, when the print coil is used as a transformer, the primary coil, the secondary coil, and a plurality of other coils all have a function of performing signal insulation and power conversion. , There is a possibility of handling a large current, and the conductor resistance value becomes important. Here, the present invention provides a printed coil in which a coil formed by a printed wiring circuit technique is conductor-reinforced by electroplating, and a coil pattern having a required conductor thickness can be obtained by a simple process, and a method for manufacturing the same. The purpose is to do.

[0006]

The present invention which achieves such an object provides a coil pattern formed by a printed wiring technique on an insulating substrate and an electroplating layer formed by electroplating on the coil pattern. The printed coil is characterized in that the conductor of the coil pattern is reinforced.

Further, according to the present invention, a plurality of coil patterns arranged in the vertical and horizontal directions on the surface of the substrate are provided on an insulating substrate by a printed wiring technique, and a connection pattern for connecting the coil patterns to each other is provided. , The conductor reinforcement of the plurality of coil patterns is performed by electroplating such that each coil pattern becomes one electrode through this connection pattern, and then the connection circuit portion is removed and the unit coil patterns are separated. Includes a structured print coil.

Furthermore, in the method for manufacturing a printed coil according to the present invention, a plurality of coil patterns arranged on the insulating substrate in the vertical and horizontal directions on the surface of the substrate by the printed wiring technique are connected to each other. A step of making a connection pattern, and a step of performing electroplating so that each coil pattern becomes one electrode via the connection pattern, and a step of reinforcing the conductors of the plurality of coil patterns, and after the step, The removal process and the separation process for each unit coil pattern are performed.

[0009]

The coil pattern is formed on the insulating substrate by the printed wiring technique. An electroplating layer is formed by performing electroplating on this coil pattern so that the coil pattern constitutes one electrode. This electroplating layer functions to reduce the electric resistance of the coil pattern and also acts to reinforce the conductor of the coil pattern.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the configuration of a print coil according to the present invention, and FIG. 2 is a sectional view thereof. In these figures, 1 is an insulating substrate, which is made of, for example, a resin material or an insulating film. Reference numeral 2 is a coil pattern formed on the insulating substrate 1. In this example, the case where the coil patterns are formed on both surfaces of the insulating substrate 1 is shown, and the coil patterns formed on both surfaces are electrically connected through the through holes 3. Reference numerals 41 and 42 denote external connection terminals provided on the end surface (side surface) of the insulating substrate 1.

In the cross section of the coil pattern 2 and the through hole 3 shown in FIG. 2, 20 is an original coil pattern or through hole land (conductor pattern) formed by a printed wiring technique, and 21 is an electrical pattern on the original pattern. The original pattern is reinforced by the plating layer formed by plating, and the conductor thickness is increased as a whole pattern.

Here, the original coil pattern, the through hole and the conductor pattern inside thereof are formed by a method already established by the printed wiring technique such as etching, vapor deposition, electroless plating and the like. Although the coil patterns are formed on both surfaces of the insulating substrate 1 in this example, the coil patterns may be formed on only one surface, and the shape of the coil patterns may be spiral. The shape is not limited to a shape, but a shape such as a meander line shape or a hoop shape is selected according to the purpose of application of the print coil.

FIG. 3 is an explanatory view showing the main parts of the method of manufacturing the printed coil having the structure shown in FIGS. 1 and 2 according to the respective steps. Corresponds to the process (procedure). Process (a) The length of the substrate surface is vertically
A plurality of coil patterns 2 arranged in the lateral direction and a connection pattern 5 for connecting the coil patterns to each other are formed. As a material of each of these patterns, for example, copper having a low electric resistance is used.

Here, the connection pattern 5 has a lower pattern density than that of the plurality of coil patterns 2. Step (b) Electroplating is performed so that each coil pattern 2 constitutes one electrode circuit via the connection pattern 5, and a plating layer is provided on each of the conductor surfaces of the plurality of coil patterns to reinforce the conductor of each coil pattern 2. I do. Here, each coil pattern 2 is a continuous curve, and since all the coil patterns on the insulating substrate 1 are electrically at the same potential via the connection pattern 5, these coil patterns are One of the electrode circuits is effectively constructed. Therefore, in the electroplating process, the copper plate 6 is used as the other electrode circuit,
Immerse the insulating substrate (coil substrate) and the copper plate 6 in the plating bath,
A copper plating layer can be provided on the surface of the coil pattern 5 by applying a voltage with the copper plate side being the positive side and the coil substrate connection pattern 5 being the negative side.

The thickness of the plating layer depends on the plating process time,
It can be adjusted according to the magnitude of the voltage. Step (c) The connection pattern portion 5 is removed from the coil substrate including the plurality of coil patterns 2 which are conductor-reinforced through the plating step. The removal of the connection pattern 5 portion can be performed, for example, by etching or, in the case where a part of the connection pattern portion is used as a lead wire to the coil pattern, a mechanical separation operation.

When the connection pattern is removed by etching, since the pattern density of the connection pattern 5 is lower than the pattern density of the coil pattern 2, it can be easily removed by etching. Step (d) In a coil substrate including a plurality of coil patterns, separation for each unit coil pattern is performed using, for example, a cutter or the like. Note that this separation work may be performed in combination with the connection pattern part separation work described in step (c). Further, the unit coil is configured by one coil pattern here, but may be separated so as to configure the unit coil by a plurality of coil patterns.

FIG. 4 is a diagram showing another example of the connection pattern 5 for connecting the plurality of coil patterns 2 to each other. In this embodiment, the connection pattern 5 is composed of a plurality of coil patterns 2.
A common mother boat shape extending between them and along the arrangement direction is provided, and the lead pattern 50 having one end connected to each coil pattern is provided in the common mother boat connection pattern 5.

According to this embodiment, the connection pattern 5 part can be removed by mechanically removing the common mother boat-shaped connection pattern 5 part from the substrate, and at the same time, the lead pattern 50 can be formed. FIG. 5: is a figure which shows a part of other manufacturing method of this invention. In this example, it is assumed that a plurality of coil patterns are formed on both surfaces of the insulating substrate and that the coil patterns on both surfaces are electrically connected by through holes provided in the substrate.

Step (a) A conductive layer (for example, a copper layer) 10 is formed on both surfaces of the insulating substrate 1, and through holes 3 are formed at predetermined places. Step (b) Electroless plating is applied to the entire substrate to form the conductive layer 30 in the through hole 3.

Step (c) A resist layer 31 is applied to predetermined portions of the substrate where coil patterns, connection patterns, lead patterns, through hole lands, etc. are to be formed. Step (d) The conductive layer 10 other than the portion where the resist layer is applied is removed by etching to form a circuit pattern such as a coil pattern, a connection pattern, a lead pattern, a through hole land, and then the resist layer 31 is removed. To do.

Step (e) Rather than using a plurality of coil patterns 2, through hole lands, etc. as one electrode circuit, electroplating is performed using the connection pattern 5, and a plating layer 21 is formed on the conductor layer of the coil patterns and through holes. Are formed and the conductor is reinforced. FIG. 6 is a diagram showing an example of a method for removing the connection pattern 5 for connecting a plurality of coil patterns by etching. Here, it is assumed that the connection pattern 5 provided on the outer peripheral portion of the substrate is removed.

Step (a) Electrodeposition etching resist layer (electrodeposition resist layer) 51
To form. Formation (adhesion) of electrodeposition resist layer here
, The plurality of coil patterns 2 and the connection pattern 5 for connecting them to each other remain as they are. Therefore, by using these again as the electrode circuit, the electrodeposition resist constitutes the electrode circuit. Only the coil pattern and the connection pattern are attached in a self-aligned manner. Therefore, even if the coil pattern and the connection pattern have irregularities, the electrodeposition resist layer 51 can be applied uniformly and with high accuracy. Also, the total amount of adhesion can be reduced.

Step (b) The removal pattern is transferred and exposed from the electrodeposition resist layer, and then developed. Step (c) The connection pattern portion 5 is removed by etching, and then the electrodeposition resist layer 51 is removed.

Although the terminal structure for connecting the coil pattern to an external circuit is not shown in the above description, for example, a part of the connection pattern 5 is used as a lead wire, and an external device connected to the lead wire is used. You may make it provide the terminal for circuit connection on the end surface of a board | substrate. Alternatively, a pin for connecting an external circuit may be provided in a part of the connection pattern.

[0025]

As described above in detail, according to the present invention, the coil pattern formed by the printed wiring circuit technology is reinforced by electroplating, and the following features are provided. You can (A) The original shape of the coil pattern is performed by using the printed wiring circuit technology, and the coil spacing can be accurately formed. By forming the plating layer to reinforce the conductor thickness, a large current can be generated. A coil that can be handled can be realized. (B) When manufacturing a plurality of printed coils from a single substrate, since the plurality of coil patterns are placed at the same potential through the connection pattern, electroplating is performed on each coil pattern simultaneously under the same conditions. It is possible to realize a printed coil of uniform quality at a low cost. (C) Since the connection pattern for connecting the coil patterns to each other can be removed or a part of the connection pattern can be used as a lead wire, the connection pattern portion does not affect the coil characteristics.

The print coil having such a structure can be applied to various fields such as an antenna for transmitting and receiving electromagnetic waves, a coil for detecting a magnetic field, a choke coil, in addition to being used for a transformer in combination with a core.

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of a print coil according to the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a print coil according to the present invention.

FIG. 3 is an explanatory diagram showing the main parts of the method for manufacturing the printed coil having the configuration shown in FIGS. 1 and 2 in accordance with each step.

FIG. 4 is a diagram showing another example of a connection pattern 5 for connecting a plurality of coil patterns 2 to each other.

FIG. 5 is a diagram showing a part of another manufacturing method of the present invention.

FIG. 6 is a diagram showing an example of a method of removing a connection pattern 5 for connecting between a plurality of coil patterns by etching.

[Explanation of symbols]

 1 Insulating substrate 2 Coil pattern 3 Through hole 41, 42 External connection terminal 20 Original coil pattern 21 Plating layer 5 Connection pattern

Claims (6)

[Claims] 1. A coil pattern formed by a printed wiring technique on an insulating substrate, and an electroplating layer formed by electroplating on the coil pattern to reinforce the conductor of the coil pattern. Print coil to do. 2. A coil pattern is formed on both surfaces of an insulating substrate, and through holes for connecting the coil patterns formed on the both surfaces to each other are formed in the insulating substrate, and conductors in the through holes are also formed. The printed coil according to claim 1, wherein the conductor is reinforced by electroplating. 3. A plurality of coil patterns arranged in the vertical and horizontal directions on the surface of the substrate are provided on an insulating substrate by a printed wiring technique, and a connection pattern for connecting the respective coil patterns to each other is provided. A print configured by reinforcing the conductors of the plurality of coil patterns by electroplating so that each coil pattern becomes one electrode through the conductor, and then removing the connection circuit portion and separating each unit coil pattern. coil. 4. A plurality of coil patterns arranged on the insulating substrate in the vertical and horizontal directions on the surface of the substrate by a printed wiring technique,
A step of making a connection pattern for connecting the respective coil patterns to each other, and a step of performing electroplating so that each coil pattern becomes one of the electrodes through the connection pattern to reinforce the conductors of the plurality of coil patterns. A method for manufacturing a printed coil, comprising the steps of removing the connection pattern portion and separating each unit coil pattern after the above steps. 5. The method for manufacturing a printed coil according to claim 4, wherein the connection pattern portion is removed by etching. 6. The method according to claim 5, wherein the etching resist is formed by utilizing an electrode circuit formed of the connection pattern portion prior to the removal of the connection pattern portion by etching.
Of manufacturing printed coil of.