JPH0845759A - Manufacture of inductance component - Google Patents

Abstract

PURPOSE:To provide a manufacturing method excellent in reliability and productivity, regarding an inductance component like a rotary transformer. CONSTITUTION:Conductor paste 17 is printed on a substratum 11 in which a trench part 12 is formed, by using a screen mask 13 provided with mask parts 16 for the trench part which are positioned in the part corresponding with the trench part 12 and have a thickness to abut against the bottom surface of the trench part 12 at the time of printing. Thereby coil conductor patterns 19 are formed in the trench part 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an inductance component such as a rotary transformer used in a video tape recorder, a digital tape recorder or the like for supplying and taking out an electric signal from a rotating body to an external stationary body. .

[0002]

2. Description of the Related Art Generally, in a rotary transformer, a rotary side is attached to a cylinder shaft of a rotary magnetic head, and a fixed side is arranged so as to face the rotary side.
It is configured to face each other with an interval of 80 μm.

As a conventional rotary transformer of this type, an annular groove is formed in a ferrite sintered body and a coil conductor having an insulating coating is wound around the annular groove, or a ferrite, alumina, titania or the like is burned. The united body is used as a base body, and a coil conductor pattern and a ferromagnetic film pattern are formed on the flat surface of the base body by printing, vapor deposition or sputtering.

Although the one adopting the above printing method is easy to manufacture, in order to improve the transmission characteristics of the rotary transformer, it is necessary to print the coil conductor pattern portion in the annular groove, and therefore the coil conductor pattern is formed. There is a need for the technique of printing in the annular groove of the substrate rather than printing on a flat surface.

In this respect, a coil conductor pattern is printed on a flat substrate, and a ferromagnetic film pattern is printed in between, so that the coil conductor pattern is finally printed in the annular groove. When printing the coil conductor pattern on the flat surface of, the thickness of the coil conductor pattern cannot be obtained sufficiently by one printing, and it is necessary to repeat printing and drying many times, which is significantly inferior in terms of productivity. It turned out to be.

Therefore, as described above, it is advantageous to form the annular groove in the base body in advance and form the coil conductor pattern in the annular groove in order to improve the productivity.

A case where a coil conductor pattern is printed in the annular groove of such a substrate by a screen printing method will be described with reference to FIGS. 3 (a) to 3 (c). Fig.3 (a)-
In (c), 1 is a base having a groove 1a, and 2
And 3 are screen masks for printing the coil conductor pattern, 2 is a patterned mask portion, and 3 is a mesh portion. Reference numeral 4 is a conductor paste to be printed on the groove 1a of the base 1, and 5 is squeegee rubber.

First, as shown in FIG. 3 (a), a screen mask is positioned and fixed to the substrate 1,
As shown in (b), the conductor paste 4 is supplied onto the screen mask, the squeegee rubber 5 is moved in the direction of the arrow, and the screen mask is deformed in the groove portion 1a by the printing pressure of the squeegee rubber 5. Groove 1
Print on the bottom of a.

However, as shown in FIG. 3B, since the mask portion 2 of the screen mask does not come into contact with the bottom surface of the groove portion 1a during printing, printing bleeding occurs in the coating film of the conductor paste 4. As a result, as shown in FIG. 3C, the coil conductor pattern 6 printed in the groove portion 1a of the substrate 1 is short-circuited as a result of printing bleeding.

[0010]

As described above, in the conventional screen printing method, the coil conductor pattern 6 printed in the groove portion 1a of the substrate 1 is short-circuited as a result of printing bleeding, and a predetermined coil conductor pattern 6 is formed. It was impossible.

For this reason, it is said that the screen printing method cannot be used for printing on the groove portion, and the method such as tampon printing was used for printing. However, this tampon printing can provide a sufficient film thickness. There was a defect that it was not there.

It is an object of the present invention to provide a method of manufacturing an inductance component using a screen printing method, which eliminates the above-mentioned conventional defects, obtains a sufficient printed film thickness, and is excellent in productivity. To do.

[0013]

In order to solve the above-mentioned problems, the present invention provides a screen having a thickness such that the mask portion for the groove portion abuts the bottom surface of the groove portion at the time of printing with a squeegee at the position of the screen mask corresponding to the groove portion of the substrate. In this method, a coil conductor pattern is printed on a groove portion of the base body using a mask and a conductor paste using a squeegee.

[0014]

With the above method, since the mask portion of the screen mask contacts the bottom surface of the groove portion when printing on the groove portion, the conductor paste is regulated so that the print bleeding does not occur and the coil conductor pattern formed on the groove portion. It is possible to completely prevent the occurrence of short circuit, and to obtain a coating film having a large thickness.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing an inductance component of the present invention will be described below with reference to the drawings. 1 (a)-(c)
FIG. 4 is a cross-sectional view of respective manufacturing steps showing an embodiment of a method of manufacturing an inductance component according to the present invention.

In FIG. 1, 11 is a substrate made of a green sheet or a sintered body of ferrite, alumina, titania or the like in which a groove portion 12 is formed, 13 is a screen mask, and this screen mask 13 is a mesh portion formed by knitting a stainless wire. 14 and this mesh part 1
A mask portion 15 is formed on the lower surface of 4 by exposing a film obtained by applying a photosensitive emulsion to the mesh portion 14 to form a print pattern, and at the position corresponding to the groove portion 12 of the substrate 11, the bottom surface of the groove portion 12 at the time of printing. Is formed by forming a groove mask portion 16 made of a photosensitive emulsion having a thickness that abuts against.

Reference numeral 17 is a conductor paste made of silver or the like, 18
Is a squeegee rubber, and 19 is a printed coil conductor pattern.

The manufacturing method will be described with such a structure. As shown in FIG. 1A, the screen mask 13 and the groove portion mask portion 16 are positioned so that the screen mask 13 and the groove portion mask portion 16 are located at predetermined positions with respect to the substrate 11. Then, the conductor paste 17 is supplied onto the screen mask 13, and the squeegee rubber 18 is moved in the arrow direction as shown in FIG. 1B to print the conductor paste 17 on the groove 12 of the base 11.

At this time, the mask portion 16 for the groove portion of the screen mask 13 contacts the bottom surface of the groove portion 12 of the base 11,
The printed conductor paste 17 can be printed without lateral bleeding. As a result, the groove 12 of the base 11
The coil conductor pattern 19 printed on has a shape that does not cause a short circuit as shown in FIG.

The mask portion 15 and the groove portion mask portion 1
The main component of the light-sensitive material of 6 is an emulsion obtained by emulsion-polymerizing vinyl acetate in an aqueous solution of polyvinyl alcohol, to which a diazo resin is added as a photosensitizer. Depending on the amount of other additives (epoxy resin, etc.), The photosensitivity is adjusted, and the organic solvent resistance (mainly during mask cleaning) and the sand edge property during exposure are adjusted.

In the step of forming a mask made of a photosensitive emulsion having a step according to the present invention, coating of a photosensitive emulsion and film exposure are repeated twice to form two mask thicknesses. First, in order to make the photosensitive emulsion thickness of the mask portion 15 other than the groove portion 5 to 10 μm, the photosensitive emulsion A is applied to the mesh portion 14 stretched on the plate frame, and exposed to ultraviolet rays using a positive film having a printing pattern of the groove portion 12. Further, a light-sensitive emulsion B is formed on top of it and has a thickness (25 to 8
5 μm) corresponding to the groove portion 12 mesh portion 1
No. 4 was applied to the coating film No. 4 and dried, and then alignment was performed using a positive film having a pattern for forming the mask portion of the groove portion 12 so as not to cause misalignment of the pattern alignment position at the time of the first exposure, and UV exposure was performed to eliminate unnecessary etching. Emulsion part is removed to complete.

As the photosensitive emulsion A, a film having a strong organic solvent resistance in a screen mask washing step of an organic solvent and a film quality capable of withstanding the printing pressure load of the squeegee rubber 18 at the time of printing was selected.
Compared with the photosensitive emulsion A, the photosensitive emulsion B has a larger mixing ratio of the photosensitive material, so that the emulsion portion (groove mask portion 16)
Even when the thickness is thick, the photosensitivity is reduced to reduce the side edge amount (pattern error) due to the halation (circulation of incident light on the emulsion film) during exposure, and to prevent the occurrence of cracks during printing, the groove mask In order to give the portion 16 flexibility, a film having a soft film quality was selected.

Further, the colors of the light-sensitive emulsion A and the light-sensitive emulsion B were changed by additives such as a coloring agent so that the two kinds of light-sensitive emulsion materials could be handled correctly and the alignment at the time of film exposure was easy. . However, even when the photosensitive emulsion A and the photosensitive emulsion B are made of the same material, they can be used if the photosensitive emulsion is selected in consideration of the above problems. Further, the size of the groove portion mask portion 16 thickened by this special screen mask with respect to the size (width, length) other than the depth of the groove portion 12 of the base 11 allows the groove portion mask portion 16 to be inserted into the groove portion 12 at the time of printing. Thus, the size of the groove 12 is made smaller by at least 50 μm.

Next, a method for manufacturing a flat plate rotary transformer as an example of the inductance component of the present invention will be described with reference to FIGS. In FIG. 2, 3
Reference numeral 1 is a base made of ferrite, 32 is an annular groove formed on one main plane of the base 31, and 33 is an annular groove 3 of the base 31.
2 is a through hole for taking out the coil conductor pattern formed in 2; 34 is a through hole conductor formed in this through hole 33; 35 is a coil conductor pattern formed in the annular groove 32 of the base 31; and 36 is also in another annular groove 32. A short ring conductor pattern formed on the substrate 31 and a terminal electrode 37 formed on the other main plane of the base 31.

A method of manufacturing the above-described structure will be described. As shown in FIG. 2A, a base 31 made of a ferrite core forming a rotary transformer is a sintered body made by extrusion molding a ferrite material, a green sheet, a printed laminate, etc., and includes an annular groove 32 and a through hole 33.
Prepare the processed one. Next, as shown in FIG. 2B, a Ag plate paste adjusted to have an appropriate viscosity by screen printing is printed on a flat surface opposite to the annular groove 32 of the substrate 31 by using a metal plate, and the through-hole conductor 34 is formed. To form.
At the time of this printing, a proper amount of through-hole air is sucked from the surface side of the annular groove 32 to form a conductor paste with less protrusion. 120 to 15 after printing
Dry for 10 to 15 minutes at 0 ° C. The description of the drying is omitted because it is all dried after printing. In FIG. 2C, Ag is produced by using the special screen of the present invention described in FIG.
The coil conductor pattern 35 and the short ring conductor pattern 36 are formed by paste by screen printing.

Further, as shown in FIG. 2D, the terminal electrode 37 is formed by printing an Ag-based paste by a screen printing method. The sintered body on which the above conductor is formed is fired in a firing furnace at a peak temperature of 700 to 920 ° C. for a peak time of 5 to 20 minutes to be metallized. Although the metallization of the Ag-based conductor on the sintered base 31 is described in the embodiment, the base made of unsintered green sheet and the Ag-based conductor can be simultaneously fired.

In order to prevent oxidation and Ag migration of the Ag-based conductor on which the coating film was formed, a protective film having a thickness of 1 μm or less such as a fluorine coat film was formed by coating after the above steps.

Further, in the embodiment, the thickness of the mask portion 16 for the groove portion of the special screen mask of the present invention has been described with respect to a total of two types of thicknesses of the mask portion 15 other than the groove portion 12. However, the depth of the groove portion is different in the printed multilayer substrate. In the case of two or more types, various shapes can be coped with by using a screen mask having three or more types of mask portion thickness.

In the embodiment, the groove depth is 20 to 80 μm.
The thickness of the mask portion was set in the range of 25 to 85 μm according to the above, but it is easily expected that the effect will be obtained if the thickness is less than this range. Further, even when the mask thickness exceeds 90 μm, if the patterning of the mask of the screen mask is possible, it can be expected that the above effect can be obtained by using this. With the current mask patterning technology, a mask thickness of 500 μm is possible, and this thickness is considered to be possible.

As described above, by using the special screen mask of the present invention, it is possible to print on the groove portion of the substrate, which is not good at screen printing, and it is expected to be applied to various kinds of inductance parts in the future.

[0031]

As described above, according to the method for manufacturing an inductance component of the present invention, the coil conductor pattern can be formed by screen printing with a sufficient film thickness in the groove portion of the substrate and without causing a short circuit due to the print bleeding. Therefore, the reliability and productivity can be improved, and the industrial value is great.

[Brief description of drawings]

1A to 1C are cross-sectional views of respective steps showing an embodiment of a method for manufacturing an inductance component of the present invention.

2A to 2D are cross-sectional views of respective steps showing a method for manufacturing the flat plate rotary transformer.

3A to 3C are cross-sectional views of respective steps showing a conventional method of manufacturing an inductance component.

[Explanation of symbols]

 11 Base 12 Groove 13 Screen Mask 14 Mesh 15 Mask 16 16 Mask for Groove 17 Conductor Paste 18 Squeegee Rubber 19 Coil Conductor Pattern 31 Base 32 Annular Groove 33 Through Hole 34 Through Hole Conductor 35 Coil Conductor 36 Short Ring Conductor 37 Terminal Electrode

Front page continued (72) Inventor Shinji Harada 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. A screen mask having a thickness such that a groove portion mask portion abuts a bottom surface of the groove portion at the time of printing with a squeegee at a position of the screen mask corresponding to the groove portion of the substrate,
A method for manufacturing an inductance component, wherein a coil conductor pattern is printed on a groove portion of the base by using a conductor paste with a squeegee. 2. The method of manufacturing an inductance component according to claim 1, wherein the mask portion for the groove portion of the screen mask has the same depth as the groove portion. 3. The method for manufacturing an inductance component according to claim 1, wherein the rotary transformer is formed by printing a coil conductor pattern and a short ring conductor pattern on the groove of the base.