Untitled record

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to a method for manufacturing a two-layer structure sheet coil used in consumer equipment such as a small video camera.

【0002】

[Conventional technology]

In recent years, there has been a demand for thinner and smaller and lighter consumer equipment, and along with this, there is a strong demand for thinner and smaller and lighter seat coils used in consumer equipment. However, it is difficult to manufacture a seat coil that can satisfy both the shape that can meet such a demand and the characteristics that have been conventionally requested. Therefore, the reality is that current seat coils sacrifice either shape or characteristics. For example, as a sheet coil used in consumer equipment such as a small video camera, a sheet coil having a two-layer structure composed of a metal conductor layer and an insulator layer is provided. This type of seat coil is manufactured, for example, as follows. That is, in order to satisfy the characteristics, a thick square copper foil is used for the purpose of reducing the electric resistance of the metal conductor layer, and the precursor solution of the insulator sheet is cast on the copper foil to cast the copper foil. A quadrangular two-layer base material in which an insulator sheet and an insulator sheet are integrally formed is produced. Then, as shown in FIG. 7, a photoresist 12 was formed on the copper foil 10, and then the photoresist 12 was formed into a photo pattern by a conventional photo process. Next, as shown in FIG. 8, the copper foil 10 is formed into a coil shape using an etching solution, and then the photoresist 12 is removed using a special stripping solution. As shown in FIG. 9, the two-layer structure sheet coil thus obtained has a shape as it is formed, that is, a coiled copper foil formed in a desired coil shape on a rectangular insulator sheet 11. 10 will be formed.

【0003】

[Problems to be Solved by the Invention]

However, in the above-mentioned two-layer structure sheet coil, in addition to the indispensable coiled copper foil 10, the insulator sheet 11 which plays only an auxiliary role occupies a large thickness, and this is the thinning of the two-layer structure sheet coil. It is an adverse effect of compactness and weight reduction. For this reason, the reality is that it has not been possible to make consumer equipment thinner, smaller and lighter. Therefore, in the two-layer structure sheet coil, a device has been developed in which the shape of the insulator sheet 11 is formed into a desired shape so that it can be matched with the shape of the mounting portion of the consumer equipment to be mounted, the arrangement of parts, and the like. Has been done. In this case, the degree of freedom in the shape of the mounting portion of the consumer device, the arrangement of parts, etc. is increased, and the consumer device can be made thinner, smaller and lighter. Further, the characteristics of the two-layer structure sheet coil depend on the thickness and shape of the copper foil 10 regardless of the shape of the insulator sheet 11, so that the characteristics conventionally possessed can be maintained. In manufacturing a two-layer structure sheet coil having such a structure, as a method of forming the insulator sheet 11 into a desired shape, a method of selectively processing the insulator sheet 11 by laser etching is particularly effective. Is. However, in this method, when a sheet body that is easily bent such as a two-layer structure sheet coil is targeted, the sheet coil bends and wrinkles are generated during laser etching processing, which greatly affects the finish. The problem arises.

【0004】

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for producing a two-layer structure sheet coil that is not deformed during processing.

【0005】

[Means for solving problems]

In order to achieve the above object, in the method for producing a sheet coil having a two-layer structure of the present invention, a two-layer base material composed of a metal conductor layer and an insulator layer is prepared, and the metal conductor of the two-layer base material is prepared. This is a method of manufacturing a two-layer structure sheet coil by forming a layer into a coil shape and then performing laser etching on the insulator layer. Prior to the laser etching, foaming is performed by heating to reduce adhesive strength. The peelable sheet is attached to the outer surface of the coiled metal conductor layer, and after the laser etching, the foamable peelable sheet is heat-peeled.

【0006】

[Action]

That is, in the method for producing a sheet coil having a two-layer structure of the present invention, a foam-removable sheet that foams by heating and whose adhesive strength decreases is attached to the outer surface of the metal conductor layer prior to laser etching. Therefore, the foam-removable sheet acts as a holding body, and the two-layer structure sheet coil becomes stiff, and deformation such as bending or bending does not occur even during processing by laser etching. Moreover, after the laser etching process, the foam-removable sheet can be easily peeled off by simply heating it, and even during this peeling, the two-layer structure sheet coil does not break or bend, and therefore, it is reliable. It does not cause a decrease. Further, the peeling does not have to be performed immediately after the laser etching, and if the peeling is performed after mounting on the mounting device, the handling at the time of mounting becomes easy and the deformation of the two-layer structure sheet coil at the time of mounting can be prevented. ..

【0007】

Next, the present invention will be described in detail.

【0008】

The two-layer structure sheet coil that is the subject of the present invention comprises a metal conductor layer and an insulator layer.

【0009】

The constituent material of the metal conductor layer is not particularly limited as long as it has electrical conductivity and can be formed into a desired shape, and is, for example, various metals such as gold, silver, copper, nickel, and cobalt. Alternatively, these alloys and the like can be mentioned. In particular, copper having the above two characteristics is preferably used.

【0010】

The constituent material of the insulator layer is not limited as long as it is a film having electrical insulating properties and flexibility, and polyester resin, epoxy resin, urethane resin, polystyrene resin, polyethylene resin, etc. It can be selected according to the purpose regardless of whether it is a thermocurable resin such as a polyamide resin, a polyimide resin, an acrylonitrile-butadiene-styrene (ABS) copolymer resin, a polycarbonate resin, or a silicone resin, or a thermoplastic resin. In particular, it is preferable to use a polyimide resin from the viewpoint of matching heat resistance, mechanical strength, and coefficient of linear expansion of the metal conductor layer. When a polyimide resin is used as a constituent material of the insulator layer, a polyimide precursor solution may be applied and then dehydrated and ring-closed to obtain a polyimide, or the soluble polyimide may be heated and pressed to form the polyimide. You may. The role of the insulator layer is a holding body for preventing the metal conductor layer formed in a coil shape from being separated, and the thickness thereof may be as long as it has strength as a holding body, and it may be workable and after mounting. From the viewpoint of thinning the equipment, it is better to be thin, and it is set in the range of 1 to 50 μm, preferably in the range of 3 to 15 μm.

【0011】

In the present invention, prior to laser etching the two-layer structure sheet coil, a foam-removable sheet is attached to the outer surface of the metal conductor layer of the two-layer structure sheet coil, and after the laser etching, the foam-removable sheet is formed. Is heated and peeled off.

【0012】

As a method for producing a base material having a two-layer structure of the metal conductor layer and the insulator layer, a method of casting a precursor solution of the insulator layer on the metal conductor layer and a method of heating and pressurizing a thermoplastic film are performed. There are methods such as crimping, laminating a thermoplastic film on a metal conductor layer and pressing it while heating to bond it, sputtering, various vapor deposition, various plating on the insulator layer, or a combination of these. is there. In particular, casting with good adhesion between the metal conductor layer and the insulator layer is preferable.

【0013】

The processed shape of the insulator layer may be larger than the size of the metal conductor layer, and may be smaller than the size of the metal conductor layer depending on the size of the consumer equipment to be mounted. As a method for processing such a metal conductor layer, methods such as machining, laser processing, optical processing, and chemical etching processing are used. When a polyimide resin is used as a constituent material of the insulator layer, it is preferable to perform perforation by irradiating an excimer laser.

【0014】

The foam-removable sheet is composed of a sheet and an adhesive layer. As the constituent material of the sheet, plastic films such as engineering plastics such as polyester, polycarbonate, polyimide, polyamide and polyphenylsulfone, polypropylene, acrylic film, synthetic rubber sheet and the like are used. As a constituent material of the pressure-sensitive adhesive layer, an acrylic-based, rubber-based, or silicone-based foamed pressure-sensitive adhesive is used. The foamed pressure-sensitive adhesive has appropriate adhesiveness at room temperature, so that it can be attached to the outer surface of the metal conductor layer, and the pressure-sensitive adhesive layer is heated to 80 to 180 ° C. Inside, the foamed resin foams, and the adhesive strength sharply decreases accordingly, so that peeling can be easily performed. The adhesive strength is preferably set to 50 to 1500 g / 20 mm at room temperature and 0 to 200 g / 20 mm when heated to 80 to 180 ° C, and exhibits a lower adhesive strength.

【0015】

The foam-removable sheet is characterized in the present invention because the adhesive force of the pressure-sensitive adhesive layer is reduced by heating and the adhesive layer can be easily peeled off. On the other hand, for example, even in the case of a weakly adhesive sheet used for the same purpose, the coil is easily deformed when the weakly adhesive sheet is peeled off after mounting the sheet coil.

【0016】

In the present invention, as a method of attaching the foam-removable sheet to the outer surface of the metal conductor layer of the two-layer structure sheet coil, a commonly used method such as roll laminating is used. However, due to the characteristics of the foam-removable sheet, the above-mentioned attachment is performed at around room temperature.

【0017】

In the above manufacturing method, examples of the heating means for peeling the foam-releaseable sheet include a hot roll and hot air. Then, the heating temperature is set in the range of 80 to 180 ° C. The peeling method is not particularly limited as long as it is suitable for the peeling step or the subsequent steps.

【0018】

A normal laser is used for the laser etching process performed in the above manufacturing method, but if a special laser having an oscillation wavelength of 400 nm or less is used, the insulator layer is properly etched without giving a thermal shock. Moreover, even if the laser reaches the metal conductor layer, the metal conductor layer is not damaged, which is an excellent effect. An excimer laser is mentioned as a laser having an oscillation wavelength in the above-mentioned region, and it is preferable to use this.

【0019】

Next, an embodiment will be described.

【0020】

[Example]

As shown in FIG. 1, the two-layer structure sheet coil is composed of a copper foil (metal conductor layer) 2 having a thickness of 35 μm and a polyimide resin layer (insulator layer) 3 having a thickness of 25 μm formed on the copper foil (metal conductor layer) 2. The copper foil 2 is formed in a coil shape with a conductor width of 100 μm and a conductor spacing of 40 μm. As shown in FIG. 2, a foam-removable sheet 5 (manufactured by Nitto Denko KK, NO.3195) was laminated on the copper pattern side of such a two-layer structure sheet coil 1 at room temperature. Then, as shown in FIG. 3, an excimer laser having an oscillation wavelength of 247 nm was irradiated from the polyimide resin layer 3 side, and the polyimide resin layer 3 was processed into the shape shown in FIG. 4 by this laser etching process. In FIG. 4, the portion 3c is a connection for preventing the outer ring 3a and the inner ring 3b from being separated. A mask having the same shape as in FIG. 4 was used for the laser etching process. In this way, the polyimide resin layer 3 was processed into a desired shape by laser etching processing, but the two-layer structure sheet coil 1 was in close contact with the foam-removable sheet 5.

【0021】

After that, the two-layer structure sheet coil 1 was attached to a predetermined mounting device 7 with the copper foil 2 to which the foam-removable sheet 5 was attached facing the surface. At this time, since the foam-removable sheet 5 was attached, it could be easily mounted on the mounting device 7. Then, it was heated for 1 minute with hot air at 100 ° C., and as shown in FIG. 5, the foam-releaseable sheet 5 was peeled off. At this time, the above peeling was easily performed, and the two-layer structure sheet coil 1 was not deformed after the peeling, and was completely normal. FIG. 6 shows a two-layer structure sheet coil 1 in a state where the foam-removable sheet 5 is peeled off.

【0022】

In addition to this embodiment, the mounting method is further simplified by providing the two-layer structure sheet coil 1 and the mounting device 7 with alignment marks for mounting alignment.

【0023】

[Comparative example]

In the above example, an ultraviolet release sheet was used instead of the foam release sheet 5. Other than that, laser etching was performed in the same manner as above. In this comparative example, the sheet coil, which is a copper pattern, was completely peeled off from the ultraviolet release sheet during the laser etching process, and was deformed to the extent that it could not withstand mounting.

【0024】

[Effect of the invention]

As described above, according to the method for producing a two-layer structure sheet coil of the present invention, the foam-removable sheet is attached to the two-layer structure sheet coil prior to laser etching for processing the insulator layer, so that the sheet is held. It works as a body, and the two-layer structure sheet coil becomes stiffer, and deformation such as bending and bending does not occur even during processing by laser etching. Moreover, after the laser etching process, the foam-removable sheet can be easily peeled off by simply heating it, and even during this peeling, the two-layer structure sheet coil does not break or bend, and therefore, it is reliable. It does not cause a decrease. Further, the peeling does not have to be performed immediately after the laser etching, and if the peeling is performed after mounting on the mounting device, the handling at the time of mounting becomes easy and the deformation of the two-layer structure sheet coil at the time of mounting can be prevented. ..

[Simple explanation of drawings]

[Figure 1]

It is a manufacturing state explanatory drawing of the two-layer structure sheet coil of one Example of this invention.

[Figure 2]

It is a manufacturing state explanatory drawing of the said 2 layer structure sheet coil.

[Fig. 3]

It is a manufacturing state explanatory drawing of the said 2 layer structure sheet coil.

[Fig. 4]

It is explanatory drawing of the shape of the insulator layer which comprises the said 2 layer structure sheet coil.

[Fig. 5]

It is explanatory drawing which shows the state which the said two-layer structure sheet coil is attached to the mounting apparatus.

[Fig. 6]

It is a top view of the said two-layer structure sheet coil.

[Fig. 7]

It is explanatory drawing which shows the manufacturing method of the two-layer structure sheet coil.

[Fig. 8]

It is explanatory drawing which shows the manufacturing method of the two-layer structure sheet coil.

[Fig. 9]

It is a top view of the two-layer structure sheet coil which shows the conventional example.

[Explanation of symbols]

1 2-layer structure sheet coil 2 copper foil 3 Polyimide resin layer 5 Foam peelable sheet