JP2011238684A - Manufacturing method of three-dimensional circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a three-dimensional circuit board having desirable electrical properties.SOLUTION: The manufacturing method of a three-dimensional circuit board comprises: preparing a film circuit board 3 in which a wiring 2 is formed on one surface of an insulating film 1; and a cylindrical enclosure 4 of which an adhesive layer 5 is formed on the surface; attaching the film circuit board 3 to all around the surface of the enclosure 4 through the adhesive layer 5 so that the side of the surface on which the wiring 2 is formed is the side of the surface to which the enclosure 4 is attached; leaving the wiring 2 on the adhesive layer 5 of the surface of the enclosure 4 by removing the insulating film 1. The insulating film 1 may be desirably dissolved and removed by an etching process.

Description

  The present invention relates to a method for manufacturing a three-dimensional circuit board in which a circuit is formed over the entire circumference of a surface of a cylindrical housing such as a roller.

  In recent years, along with the downsizing, multifunctionalization, and cost reduction of electronic devices such as mobile phones, it has been required to mount circuit boards in a compact manner on the inner and outer surfaces of the casing. For this reason, a three-dimensional circuit board may be required as a circuit board. Also in the field of copying machines, it has been proposed to manufacture a three-dimensional circuit board by forming a circuit board over the entire outer surface of a cylindrical housing made of metal or resin such as a developing roller. (See Patent Document 1).

  As a means for forming a circuit board on the entire surface of the casing, there is a method in which a film-like circuit board provided with electrode wiring on the surface of an insulating film such as polyimide or polyethylene terephthalate (PET) is attached to the outer periphery of the casing. is there. This method can be said to be easier than the method of directly forming the electrode wiring on the housing because the film-like circuit board can be manufactured in a large amount and at a low cost.

  On the other hand, Patent Document 2 describes a method in which a film is attached to a cylindrical can body by a rotary cutter method. In this method, a flexible film that cannot be held on its own is cut into a predetermined length with high accuracy, and the obtained film is supplied to the can body for lamination, whereby the film is attached to the can body. It is possible to attach.

JP-A-6-59568 Japanese Patent Laid-Open No. 10-236446

  The sticking method by the rotary cutter system of patent document 2 was developed for the purpose of sticking a label on the surface of beverage containers such as cans and bottles. Therefore, it is not necessary to strictly control the accuracy of the labeling position, and when a label is applied to the entire surface of the beverage container, even if there are overlaps or gaps at both ends of the film, there is a problem. There is no.

  On the other hand, when a film-like circuit board for electronic equipment is attached to the entire circumference of the cylindrical casing, if there is an overlap or a large gap at both ends of the film-like circuit board, a short circuit or wiring will be formed in the circuit. There is a possibility that a conduction failure may occur or the toner may enter the gap to adversely affect the electrical characteristics of the circuit. Therefore, it is required that the both ends of the film-like circuit board are attached so that they do not overlap with each other and the gap between the both ends is reduced to an allowable level.

  However, even if the film-like circuit board is cut with high accuracy and is adjusted in advance so as not to cause overlapping or large gaps at both ends to be attached to the housing in order to meet such demands, Variations that occur in the circuit board cutting process cannot be avoided, and because there are variations in the finished diameter of the housing itself, the overlap at both ends of the film-like circuit board and the allowable range between both ends are exceeded. At present, the generation of the gap cannot be completely prevented.

  With respect to the gap generated between both ends, it is effective in preventing a short circuit or a conduction failure if the gap can be buried when resin is applied to protect the surface of the attached film-like circuit board. However, under the present circumstances, even if the resin for surface protection is applied, the end of the film-like circuit board may be exposed without completely filling the gap between the both ends and the step between the ends.

  The present invention has been made in view of such problems of the prior art, and in manufacturing a three-dimensional circuit board in which a desired circuit is formed on the surface of a cylindrical housing such as a roller, particularly over the entire circumference. It is an object of the present invention to provide a method of manufacturing a three-dimensional circuit board that does not adversely affect electrical characteristics caused by a gap between both ends when a film-like circuit board is attached to a housing. .

  In order to solve the above-mentioned problems, a manufacturing method of a three-dimensional circuit board provided by the present invention includes a film-like circuit board in which wiring is formed on one side of an insulating film and a cylindrical casing in which an adhesive layer is applied on the surface. And affixing the film-like circuit board over the entire surface of the housing with an adhesive layer so that the surface side on which the wiring is formed becomes the side of the attachment surface to the housing, and then the insulating film It is characterized by leaving the wiring in the adhesive layer on the surface of the housing.

  In the manufacturing method of the three-dimensional circuit board of the present invention, it is preferable to selectively dissolve and remove the insulating film of the film-like circuit board attached to the housing by an etching process.

  According to the present invention, since the insulating film of the film-like circuit board attached to the housing in the manufacture of the three-dimensional circuit board is removed later, the electrical caused by the gap between both ends of the film-like circuit board is obtained. There is no adverse effect on properties. Thus, a three-dimensional circuit board having good electrical characteristics can be obtained.

FIG. 2 is a partial cross-sectional view showing a casing and a film-like circuit board affixed to the casing in the middle of the manufacturing method of the present invention. It is affixed on the surface of the housing through an adhesive layer so as to be on the adhesive surface side. It is sectional drawing of the three-dimensional circuit board by which the wiring was formed through the adhesive bond layer on the surface of the housing manufactured with the manufacturing method of this invention. It is a perspective view of the three-dimensional circuit board manufactured with the manufacturing method of this invention.

  In the method of manufacturing a three-dimensional circuit board according to the present invention, first, a film-like circuit board in which a wiring having a predetermined pattern is formed on one side of an insulating film and a cylindrical casing having an adhesive layer applied on the surface. prepare. The insulating film is flexible enough to be easily affixed to a cylindrical casing, and is not dissolved by the etching process when forming a wiring pattern, which will be described later, but is affixed to the casing. In the later etching process, a soluble material is used.

  Specifically, polyimide or PET can be used. The thickness of the insulating film is preferably about 10 μm to 75 μm. If it is thinner than 10 μm, the rigidity is insufficient and handling becomes difficult. On the other hand, when it exceeds 75 μm, it becomes too thick and it takes too much time for the etching process after being attached to the casing.

  A method for forming a wiring having a predetermined pattern on one surface of the insulating film is not particularly limited, and a general method may be used. For example, a thin metal film such as copper or nickel having a thickness of about 0.05 to 0.1 μm is directly formed on one side of the insulating film by vapor deposition or sputtering, and the thickness of 1 to 1 is formed on the metal thin film by electroplating. A metal layer of the same material of about 10 μm is formed.

  Next, a wiring having a predetermined pattern can be formed by photolithography and etching treatment of these metal layers and the underlying metal thin film. The insulating film on which the wiring having a predetermined pattern is formed on one side is subsequently cut into a required size using a cutting means such as a cutter. Thereby, a film-like circuit board is obtained.

  The cylindrical casing is a member constituting a three-dimensional circuit board, and a metal or resin one can be used depending on the application. The adhesive layer formed on the surface of the housing is not particularly limited as long as it is not dissolved at the same time as the insulating film described later is dissolved. For example, a modified epoxy adhesive can be used.

  Examples of the formation of the adhesive layer include a method of applying an adhesive and a method of attaching a sheet-like adhesive. When the sheet-like adhesive is affixed to the housing, the joints between both ends of the adhesive sheet in the circumferential direction of the housing are separated from each other, and the gap extending in the axial direction of the housing is formed in the adhesive layer. Occur and this can be a problem. Therefore, a method of applying an adhesive which is a method in which such a gap does not occur is preferable.

  As a method for forming the adhesive layer by coating, there are a general spraying method, a dip coating method by dipping, and the like. The thickness of the adhesive layer formed on the surface of the housing is preferably about 5 μm to 100 μm. If the thickness is less than 5 μm, the adhesive ability is lowered, and there is a problem that the wiring is peeled off when polyimide etching is performed. On the other hand, when the thickness exceeds 100 μm, an excessive adhesive is applied, which causes problems of productivity and cost increase.

  Subsequently, before the adhesive layer is cured, the film-like circuit board is pasted around the entire surface of the housing so that the surface side on which the wiring is formed becomes the pasting surface side with the housing. Thereby, a film-like circuit board is affixed on the whole surface periphery of a housing via an adhesive bond layer. In this state, the adhesive layer is cured by holding for a predetermined time or longer.

  Next, the insulating film of the film-like circuit board attached to the housing is removed. Examples of the method for removing the insulating film include a method for dissolving and removing only the insulating film by etching treatment. The solvent for etching (etchant) may be a commonly used solvent such as a commercially available solvent. For example, hydrazine is well known. Thereby, since wiring remains in the adhesive layer on the surface of the cylindrical casing, a three-dimensional circuit board on which wiring having a predetermined pattern is formed is obtained. In addition, in order to protect the housing surface on which the wiring is formed after removing the insulating film, the housing surface may be covered with a resin.

  As described above, in the method of manufacturing a three-dimensional circuit board according to the present invention, even when an overlap or a gap occurs at both ends of the insulating film of the film-like circuit board when the film-like circuit board is attached to the casing, Since the insulating film is removed later, there is no adverse effect on the electrical characteristics due to these overlaps and gaps. Thus, a three-dimensional circuit board having good electrical characteristics can be obtained. In the above description, the manufacturing method of a three-dimensional circuit board having wiring on the outer surface of the casing has been described. However, a three-dimensional circuit board having wiring on the inner surface of the casing can be manufactured in the same manner.

  Hereinafter, the present invention will be described in more detail with reference to specific examples with reference to FIGS. 1 to 3, but the present invention is not limited to these examples.

[Example 1]
A 0.1 μm-thick Cu thin film is formed on one surface of a 25 μm-thick polyimide film as the insulating film 1 by sputtering, and then a 8 μm-thick Cu layer is formed on the Cu thin film by copper sulfate plating. did. A dry film resist (AQ-1158, manufactured by Asahi Kasei Co., Ltd.) is stretched on this Cu metal layer, which consists of a Cu thin film and a Cu layer, and has a thickness of 8 μm as a whole, and is exposed and developed using a predetermined mask to form a resist. A mask was formed.

  Next, the wiring 2 was formed by patterning the Cu metal layer by etching using iron chloride as an etchant. Thereafter, the resist mask was removed using an aqueous sodium hydroxide solution. The insulating film 1 having the wiring 2 obtained in this way was cut into a size of 50.4 mm × 250 mm to produce a film-like circuit board 3.

  On the other hand, an aluminum pipe having a diameter of 16 mm and a length of 300 mm was used for the housing 4. This aluminum pipe is bonded to the outer surface of the aluminum pipe by dip coating with a solution type modified epoxy adhesive (Aronmite AS-60 manufactured by Toa Gosei Co., Ltd.) diluted twice with toluene. The agent was applied. During dip coating, both ends of the aluminum pipe were closed. Next, the adhesive layer 5 was formed on the entire outer surface of the cylindrical casing 4 by drying under conditions of 100 ° C. × 2 minutes in a hot air drying furnace.

  Next, the film-like circuit board 3 was affixed to the outer surface of the housing 4 so that the surface side on which the wiring 2 was formed became the affixing surface side so that the wiring 2 was joined to the adhesive layer 5. FIG. 1 shows a state where the film-like circuit board 3 is attached to the outer surface of the housing 4. As shown in FIG. 1, a gap G is generated between both end portions of the insulating film 1. The casing 4 with the film-like circuit board 3 attached thereto was held at 150 ° C. for 30 minutes to cure the adhesive layer 5.

  Next, in order to dissolve the insulating film 1 made of a polyimide film, the housing 4 on which the film-like circuit board 3 is attached is immersed in a 50% by volume hydrazine monohydrate aqueous solution heated to 50 ° C., Hold for about 30 minutes. Thereby, the insulating film 1 made of a polyimide film was dissolved and removed. As a result, only the wiring 2 made of the Cu metal layer remained on the adhesive layer 5 formed on the outer surface of the housing 4, and a three-dimensional circuit board 10 as shown in FIGS. 2 and 3 was completed.

[Example 2]
TP3000 manufactured by Toray Engineering Co., Ltd., which is commercially available as a polyimide etching solution in place of the hydrazine monohydrate aqueous solution, for the case 4 to which the film-like circuit board 3 produced in the same manner as in Example 1 is attached. Using, the insulating film 1 made of a polyimide film was dissolved. The conditions for dissolution were immersion for about 10 minutes at a liquid temperature of 80 ° C. Also in this case, as in Example 1, the insulating film 1 made of polyimide film is completely removed and only the Cu metal layer wiring 2 remains, and the three-dimensional circuit board 10 as shown in FIGS. completed.

DESCRIPTION OF SYMBOLS 1 Insulating film 2 Wiring 3 Film-like circuit board 4 Case 5 Adhesive layer 10 Three-dimensional circuit board G Gap

Claims (2)

  Prepare a film-like circuit board with wiring formed on one side of the insulating film and a cylindrical housing with an adhesive layer formed on the surface, and form the film-like circuit board around the entire surface of this housing After attaching with an adhesive layer so that the surface side is the side to be attached to the housing, the insulating film is removed and wiring is left on the adhesive layer on the surface of the housing. Circuit board manufacturing method.   The method for producing a three-dimensional circuit board according to claim 1, wherein the insulating film of the film-like circuit board attached to the casing is dissolved and removed by etching.

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