JP4911107B2 - Three-dimensional circuit manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a three-dimensional circuit, and specifically, a three-dimensional circuit using a flexible printed circuit board on the surface of a roller made of metal or resin and having a columnar shape or a cylindrical shape. The present invention relates to a method of forming an electronic circuit.

  With the downsizing, multi-functionality, and cost reduction of electronic devices, for example, a method for providing electronic circuits in a compact manner on the inner surface and outer surface of a housing such as a mobile phone is required. In such a case, the electronic circuit may be three-dimensional rather than planar.

  In the field of copying machines, Patent Document 1 describes that an electronic circuit is formed on the surface of a roller and used for development for compactness and high image quality. In patent document 1, the flexible printed wiring board which formed the electrode in insulating members, such as a polyimide film, is obtained by sticking on the outer periphery of the normal developing roller.

  For example, it is conceivable to cut a circuit board such as a flexible printed circuit board into a predetermined size and attach this circuit board to a roller. However, when it is used as a developing roller, there is a problem that when an overlap or a gap is generated on a circuit board, a short circuit or a conduction failure occurs between wirings constituting the electronic circuit, which affects the electrical characteristics of the electronic circuit. In addition, if the circuit board cannot be attached at an accurate position, there is a problem that a trouble is caused in the subsequent assembly process when the circuit board is subjected to external energization processing.

In this case, very precise management is required for the cutting accuracy of the circuit board itself and the positional accuracy when the circuit board is attached to the roller. Since there are variations, and there are variations in the finished diameter of the rollers themselves, the current situation is that sufficient measures have not been taken to deal with such problems.
JP 2003-84560 A

  In order to solve this problem, the present inventors, as shown in FIG. 7, hold the object (3; roller) having a columnar shape or a cylindrical shape in a state where the central axis is horizontal, and A rotation mechanism (10) that rotates around the central axis as a rotation axis, and a holding mechanism (1) that holds the circuit board (1) that has been cut to a predetermined size according to the object (3) and that is horizontally transported. 20) and a circuit that can adjust the relative positional relationship between the circuit board (1) conveyed with respect to the surface of the rotating object (3) and that presses against the surface of the object (3). Using a device having a control mechanism (30) capable of controlling the pressure of the substrate (1) at a constant level, a circuit is provided via an adhesive provided on one surface of the circuit substrate (1) or the peripheral surface of the object. While controlling the pressure that presses the substrate (1) against the surface of the object (3), Proposing to horizontally move (1) and rotate the object (3) to attach the circuit board (1) to the surface of the object (3) to form a three-dimensional circuit. (See Japanese Patent Application No. 2007-322342).

  With this technique, it is possible to attach the circuit board accurately on the surface of a roller for use in electronic equipment with high positional accuracy, without overlapping, and with the gap being controlled to a minimum. However, even when trying to obtain a high-quality image using the developing roller produced by such a technique, a step is formed by a minute gap generated at both ends of the circuit board, which affects the image quality. there is a possibility.

  Accordingly, an object of the present invention is to provide a three-dimensional circuit in which there is no step due to the minute gap as described above.

  The method for producing a three-dimensional circuit according to the present invention comprises forming a three-dimensional circuit by adhering a film-like circuit board to a columnar or cylindrical casing through an adhesive, and then forming the circuit board. An ultraviolet curable resin is injected into a gap formed between the end portions in the circumferential direction, and the ultraviolet curable resin is cured by irradiating ultraviolet rays.

  With regard to the attachment of the circuit board, (1) an adhesive with a separator having adhesiveness at room temperature is attached to the casing, the base material being attached to the back surface of the circuit board; (3) Adhering a base material on which the adhesive used for heating instead of the adhesive is attached to the back surface of the circuit board to the casing while heating the adhesive; An adhesive having adhesiveness at room temperature is attached to the case, and the circuit board is attached thereon. (4) An adhesive of a type to be used by heating is attached to the case, and There is a method of attaching the circuit board from above. In the case of (1) and (2), a minute gap having a thickness between the circuit board and the adhesive layer is formed between the circumferential ends of the circuit board. On the other hand, in the case of (3) and (4), a minute gap having a thickness of the circuit board is formed between the end portions. The present invention is applicable to any case.

  When injecting the ultraviolet curable resin, a transparent resin film that transmits ultraviolet light is pasted on the gap, forming a cavity inside the resin film, and injecting the ultraviolet curable resin into the cavity, It is preferable to remove the resin film after the curing.

  At this time, it is preferable to suck from the other opening while injecting the ultraviolet curable resin from one opening of the cavity.

  In addition, it is preferable to use a resin having a volume shrinkage of less than 20% as the ultraviolet curable resin.

  According to the present invention, in a three-dimensional circuit formed by attaching a film circuit board in the circumferential direction of a columnar or cylindrical casing, there is no overlap or gap between the circumferential ends of the circuit board. Even a step due to a minute gap does not exist. Therefore, the three-dimensional circuit obtained by the present invention can be suitably used as a developing roller that is required to obtain a high-quality image.

  One embodiment of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a perspective view showing a method for forming a three-dimensional circuit of the present invention. FIG. 2 is a cross-sectional view of a housing on which a base material having an adhesive with a separator attached to the back surface of a film-like circuit board is attached. FIG. 3 shows a transparent ultraviolet ray in the state of FIG. The state which stuck the resin film which permeate | transmits is shown with sectional drawing.

  First, the base material on which the adhesive (2) with a separator having adhesiveness at room temperature is attached to the back surface of the film-like circuit board (1) is made of metal or resin, and has a columnar shape or a cylindrical shape. It sticks to the housing | casing (3) which is. Or the base material by which the adhesive (2) of the type heated and used as an adhesive is affixed on the back surface of the film-like circuit board (1) is made of metal or resin, and has a cylindrical shape or It sticks to the housing | casing (3) which is cylindrical shape. The same applies to the case where a base material on which the adhesive (2) of the type heated and used as the adhesive is attached to the film-like circuit board (1) is used.

  Thus, a minute gap (5) is generated at the end in the circumferential direction of the circuit board (1) stuck on the housing (3). Such a gap (5) is caused by a tolerance when cutting the circuit board (1) and a tolerance in manufacturing the casing (3) having a columnar shape or a cylindrical shape. As described above, such a gap can be made very small by the technique described in Japanese Patent Application No. 2007-322342, but cannot be completely removed.

  In the present invention, after forming such a three-dimensional circuit, a cavity (6) is formed by attaching a transparent resin film (4) that transmits ultraviolet light from above the gap (5). The resin film (4) may be of any size that covers the gap (5) and forms the cavity (6). As the transparent resin film (4), any resin film can be adopted as long as it is a material that transmits ultraviolet light for curing the ultraviolet curable resin filled in the cavity (6). Generally, PET (polyethylene terephthalate), PP (polypropylene), etc. are suitable.

  After affixing the resin film, an injection nozzle (7) for supplying an ultraviolet curable resin is attached to one opening of the cavity (6), and a suction nozzle for sucking the ultraviolet curable resin into the other opening ( 8) Install. In order to efficiently inject ultraviolet curable resin into the cavity (6), the length of the resin film (4) is made to be about 10 mm shorter than the length of the circuit board (1). The injection nozzle (7) and the suction nozzle (8) are attached so that an opening of about 5 mm is formed in the nozzle. The injection nozzle (7) and the suction nozzle (8) may be any flexible material, and any known material may be used. These nozzles may be connected to known mechanisms capable of supplying or discharging these resins.

  After both nozzles are attached, the ultraviolet curable resin is injected into the gap formed by suctioning from the other opening while injecting the ultraviolet curable resin from one opening of the cavity (6).

  The ultraviolet curable resin has various viscosities, and it is necessary to select an ultraviolet curable resin having an appropriate viscosity depending on the gap interval. That is, when the gap is wide, even an ultraviolet curable resin having a high viscosity can be injected into the gap, but when the gap is narrow, it is necessary to select an ultraviolet curable resin having a low viscosity. The gaps that occur vary depending on the cut length of the circuit board to be pasted. The maximum is 0.5 mm. In order to fill a cavity generated from such a gap, the viscosity of the ultraviolet curable resin needs to be 1000 mPa · s or less.

  The reason for suction when injecting the UV curable resin into the cavity resulting from the gap is that the resin film (4) stuck on the gap is in close contact with the surface of the circuit board (1) by suction. The ultraviolet curable resin is filled only in the cavity (only in the gap) without penetrating between the circuit board (1) and the transparent film. Further, when the ultraviolet curable resin is injected, the ultraviolet curable resin may be supplied by applying pressure. However, when the supply pressure becomes higher than the suction pressure, the attached resin film (4) depends on the supply pressure. Since the ultraviolet curable resin is pushed up and penetrates between the resin film (4) and the circuit board (1), it is necessary to manage the supply pressure below the suction pressure.

  After injecting the ultraviolet curable resin into the cavity (6), the ultraviolet curable resin is cured by irradiating ultraviolet rays through the transparent resin film (4). Conditions depend on the specifications of the UV curable resin used. In addition, by using an ultraviolet curable resin having a volume shrinkage ratio of less than 20% due to curing, the ultraviolet curable resin filled in the cavity is cured in almost the same volume, so that the height after curing is at the same position as the circuit board. Therefore, it can be managed in a shape without a step.

  After the ultraviolet curable resin is cured, the transparent resin film (4) is peeled off from the circuit board (1) and removed.

  Different aspects of the present invention will be described in detail below based on the drawings.

  4 is a cross-sectional view of the housing with the adhesive attached, FIG. 5 is a cross-sectional view of the state where the film circuit board is attached to the state of FIG. 4, and FIG. The state which stuck the transparent resin film to this state is shown with sectional drawing.

  The same applies to the case where the adhesive (2) is an adhesive having tackiness at room temperature or a type of adhesive that is used by heating. In this case, the minute gap is formed only for the thickness of the circuit board (1). However, even when such a thickness is small, the level difference caused by such a minute gap affects the image quality of the image.

  Therefore, such a gap is filled in the same manner as described above. In other words, except that the injection nozzle (7) and the suction nozzle (8) are replaced as necessary, the gap is filled by the filling and curing of the ultraviolet curable resin in the same manner as described above.

Example 1
In this example, after performing copper sputtering using a 35 μm thick PET film (A4100, manufactured by Toyobo Co., Ltd.) as the resin film, the conditions were as follows: copper sulfate concentration 90 g / liter, sulfuric acid concentration 180 g / A 10 μm thick copper layer was formed on the surface by forming an 8 μm thick copper coating by an electrolytic copper plating method using a liter plating bath at room temperature and a cathode current density of 2 A / dm ² .

  Thereafter, a dry film resist (AQ-1158, manufactured by Asahi Kasei Co., Ltd.) is applied to the surface by a photoresist method, a wiring shape mask is produced, exposure is performed from above the mask, development, etching, and peeling are performed. An electronic circuit was fabricated. Further, a pressure-sensitive adhesive film with a separator (Dainippon Ink and Chemicals Co., Ltd., double-sided adhesive tape # 8616) is attached to the surface opposite to the obtained electronic circuit, and then cut with a mold to obtain a circuit board. Got. The size of the circuit board was about 280 mm in length and about 50 mm in width.

  When the obtained circuit board was attached to the surface of an aluminum pipe having a diameter of 16 mm and a width of 300 mm, a minute gap was formed between the circumferential ends of the circuit board. When the size of the gap was measured, it was 0.20 mm on average.

  Above the gap, a PET film (manufactured by Kawamura Sangyo Co., Ltd.) having an adhesive layer cut with a metal mold was attached on the circuit board by the same means as that for attaching the circuit board.

  Next, an injection nozzle connected to a UV curable resin supply source is connected to one of the cavities formed by sticking the PET film, and a suction nozzle connected to a suction mechanism is connected to the other of the cavities. After each connection, UV curable resin (GL-4006, manufactured by Gure Lab Co., Ltd.) was injected from the opening and sucked from the other opening. The viscosity of the ultraviolet curable resin was 550 mPa · s.

  After filling with the ultraviolet curable resin, the ultraviolet curable resin was cured by irradiating ultraviolet rays from above the PET film with a UV lamp.

  Thereafter, the PET film was peeled off, and the state of the gap was confirmed. As a result, it was confirmed that the height of the UV curable resin was almost the same as the height of the circuit board. It was also confirmed that no cured resin was present. This indicates that when the UV curable resin was injected, the PET film adhered to the surface of the circuit board, and the UV curable resin could be injected only into the gap without penetrating between the circuit board and the PET film. ing.

(Example 2)
In this example, a two-layer substrate (S'perFlex, manufactured by Sumitomo Metal Mining Co., Ltd.) in which a Cu foil having a thickness of 8 μm was formed on a polyimide having a thickness of 38 μm was used as the resin film.

  Thereafter, a dry film resist (AQ-1158, manufactured by Asahi Kasei Co., Ltd.) is applied to the surface by a photoresist method, a wiring shape mask is produced, exposure is performed from above the mask, development, etching, and peeling are performed. An electronic circuit was produced and cut with a mold to obtain a circuit board. The size of the circuit board was about 280 mm in length and about 50 mm in width.

  Next, an adhesive film with a separator (manufactured by Nikkan Kogyo Co., Ltd., SAFW) was prepared and cut with a mold. The adhesive film had a length of about 280 mm and a width of about 50 mm.

  First, an adhesive film with a separator was attached to the entire surface of an aluminum pipe having a diameter of 16 mm and a width of 300 mm at a temperature of 100 ° C. by the same sticking method as in Example 1, and then the separator was peeled off to bond the adhesive film. A circuit board was stuck on the agent layer. Similarly, a minute gap was formed between the circumferential ends of the circuit board, and the gap was an average of 0.25 mm.

  A PET film (made by Kawamura Sangyo Co., Ltd.) with an adhesive layer cut with a mold was attached in the same manner on the gap, and after setting the injection nozzle and suction nozzle in the same manner as in Example 1, an ultraviolet curable resin ( GL-1001 manufactured by Glue Lab Co., Ltd. was sucked from the other opening while being injected from one opening. The viscosity of the ultraviolet curable resin was 22 mPa · s.

  After filling the ultraviolet curable resin, the ultraviolet curable resin was cured from above the PET film by irradiating ultraviolet rays with a UV lamp, and then the PET film was peeled off to confirm the state of the gap. Similarly, the height of the ultraviolet curable resin was confirmed to be almost the same as the height of the circuit board, and it was also confirmed that the ultraviolet curable resin was not present on the surface of the circuit board.

It is a perspective view which shows the state which fills the clearance gap between the three-dimensional circuits in this invention with the ultraviolet curable resin. It is sectional drawing which shows the housing | casing in which the base material by which the adhesive agent with a separator was affixed on the back surface of a film-form circuit board was affixed. It is sectional drawing which shows the state which affixed the transparent resin film on the state of FIG. It is sectional drawing which shows the housing | casing in which the adhesive agent was affixed. It is sectional drawing which shows the state which stuck the film-like circuit board in the state of FIG. It is sectional drawing which shows the state which affixed the transparent resin film on the state of FIG. It is the schematic of the apparatus for sticking a film-form circuit board to a housing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit board 2 Adhesive 3 Cylindrical housing 4 Transparent film 5 Crevice 6 Cavity 7 Injection nozzle 8 Suction nozzle 10 Rotating mechanism 20 Holding mechanism 30 Control mechanism 40 Standardizing mechanism 50 Heating mechanism

Claims (4)

  After a film-like circuit board is attached to a cylindrical or cylindrical housing via an adhesive, an ultraviolet curable resin is injected into a gap formed between circumferential ends of the circuit board, and ultraviolet rays are injected. A method for producing a three-dimensional circuit, wherein the ultraviolet curable resin is cured by irradiation.   When injecting the ultraviolet curable resin, a transparent resin film that transmits ultraviolet light is pasted on the gap, forming a cavity inside the resin film, and injecting the ultraviolet curable resin into the cavity, The method for producing a three-dimensional circuit according to claim 1, wherein the resin film is removed after the curing.   3. The three-dimensional circuit according to claim 2, wherein when the ultraviolet curable resin is injected into the cavity, the ultraviolet curable resin is injected from one opening of the cavity and suction is performed from the other opening. Manufacturing method.   The manufacturing method of the three-dimensional circuit as described in any one of Claims 1-3 which uses resin whose volume shrinkage rate is less than 20% as said ultraviolet curable resin.

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