JP4528052B2 - Manufacturing method of 3D circuit board and 3D circuit board - Google Patents

Description

  The present invention relates to a three-dimensional circuit board having a hollow three-dimensional shape such as a cylinder and a method for manufacturing the same.

  A method of manufacturing a three-dimensional circuit board by forming a circuit on the inner periphery of a three-dimensional substrate such as a cylinder or a sphere has been studied. For example, a conductive circuit is formed on the surface of a molded body that is formed into a spherical shape with a low-melting-point metal such as tin or solder, and this molded body is loaded in a state where a space is maintained on the inner periphery of the mold, The thermosetting resin is filled and cured, and the thermosetting resin molded body composed of the molded body and the thermosetting resin cured body on the outer periphery thereof is taken out of the mold, and the low melting point metal molded body is melted and removed. Thus, a method of manufacturing a three-dimensional circuit board formed by transferring a conductive circuit to the inner periphery of a spherical thermosetting resin cured body has been proposed (see Patent Document 1).

  In this Patent Document 1, when forming a conductive circuit on the surface of a spherical molded body, a resist film is provided on the surface of the molded body, exposed using a photomask, and developed to develop a resist corresponding to the circuit pattern. After the film is removed, a conductive material is attached to the removed portion of the resist film. However, when forming a conductive circuit through a patterning process using such a photomask, there are problems in productivity due to increased man-hours and high accuracy on the surface of a three-dimensional solid shape such as a cylindrical shape or a spherical shape. It is difficult to expose and pattern, and there is a problem that it is difficult to form a conductive circuit with high accuracy.

On the other hand, as a method for forming a conductive circuit with high accuracy on the surface of a three-dimensional solid shape, various patterning methods using electromagnetic waves such as lasers have been conventionally provided. For example, by forming a conductive layer on the surface of the substrate and irradiating the electromagnetic wave such as a laser along the boundary region between the circuit forming part and the non-circuit forming part forming the circuit in the conductive layer, the electromagnetic wave was irradiated. A method of removing a part of the conductive layer and forming a conductive circuit with the conductive layer remaining in the circuit formation portion has been proposed (see, for example, Patent Document 2).
JP-A-9-148712 Japanese Patent No. 3153682

  In this way, by forming an electrically conductive circuit by irradiating an electromagnetic wave such as a laser along the outer periphery of the circuit forming portion of the electrically conductive layer, man-hours such as resist film formation and exposure using a photomask become unnecessary. Productivity can be improved, and a conductive circuit can be formed with high accuracy on the surface of a three-dimensional solid shape by scanning and irradiating electromagnetic waves along the three-dimensional solid surface of the substrate. Is.

  However, when forming a conductive circuit on the inner surface of a base material having a facing surface such as a hollow cylinder, it is necessary to form a conductive layer on the inner side of the base material and irradiate this conductive layer with electromagnetic waves such as a laser, It is difficult to irradiate an electromagnetic wave by inserting a head that radiates an electromagnetic wave inside the substrate, and it is almost impossible to irradiate an electromagnetic wave inside a minute substrate particularly used for a micro component. Therefore, when forming a circuit on the inner surface of a three-dimensional base material having an opposing surface, a patterning method using an electromagnetic wave such as a laser cannot be applied.

  The present invention has been made in view of the above points, and an object thereof is to enable circuit formation on the inner surface of a three-dimensional base material having an opposing surface by a patterning method using an electromagnetic wave such as a laser. Is.

In the manufacturing method of the three-dimensional circuit board according to the first aspect of the present invention, the conductive layer 2 is formed on the opposite surface of the electromagnetic wave-transmitting base material 1 having a three-dimensional shape having surfaces facing each other on the inner side. In the state where the electromagnetic wave absorbing material 3 having the property of absorbing electromagnetic waves is disposed between the opposing surfaces, the base material 1 is transmitted from the side opposite to the side on which the conductive layer 2 is formed, and the conductive layer 2 is irradiated with the electromagnetic wave. At the same time, at least the conductive layer 2 in the boundary region between the circuit forming part 4 and the non-circuit forming part 5 for forming a circuit in the conductive layer 2 is removed by irradiation with electromagnetic waves.

  According to the present invention, the electromagnetic wave transmitting substrate 1 can be transmitted from the outside of the substrate 1 to irradiate the conductive layer 2 formed on the opposing inner surface of the substrate 1 with the electromagnetic wave. The electromagnetic wave absorbing material 3 can prevent electromagnetic waves from reaching the conductive layer 2 on the surface facing the conductive layer 2 that irradiates the conductive layer, and the conductive layer inside the three-dimensional substrate 1 having the facing surface. Circuit formation can be performed by patterning method 2 using electromagnetic waves.

  The invention of claim 2 is characterized in that, in claim 1, the conductive layer 2 is formed by electroless plating.

  According to the present invention, the conductive layer 2 can be formed by applying an electroless plating solution to the substrate 1, and the opposing surface of the substrate 1 is a closed surface such as a cylindrical shape. However, the conductive layer 2 can be easily formed.

  Further, the invention of claim 3 irradiates the electromagnetic wave in a state where the fluid is used as the electromagnetic wave absorbing material 3 in the first or second aspect and the electromagnetic wave absorbing material 3 is disposed between the opposing surfaces of the substrate 1 while flowing. It is characterized by doing.

  According to the present invention, the conductive material that is removed from the conductive layer 2 by the irradiation of electromagnetic waves and scattered can be removed by the flow of the electromagnetic wave absorbing material 3, and the scattered conductive material is formed and reattached. It is possible to prevent the occurrence of defective insulation.

  The invention of claim 4 is characterized in that, in claim 3, the electromagnetic wave absorbing material 3 made of a fluid is a mixture of powder 3a for absorbing electromagnetic waves in a gas or liquid.

  According to this invention, the electromagnetic wave can be efficiently absorbed by the powder 3a having a high electromagnetic wave absorptivity, and it is ensured that the electromagnetic wave reaches the conductive layer 2 on the surface facing the conductive layer 2 that irradiates the electromagnetic wave. It can be prevented.

  A three-dimensional circuit board according to a fifth aspect of the present invention is manufactured by the method according to any one of the first to fourth aspects, and has an inner surface facing a highly accurate circuit by patterning using an electromagnetic wave. The formed three-dimensional circuit board can be obtained.

  According to the present invention, the electromagnetic wave transmissive substrate 1 can be transmitted from the outside of the substrate 1 to irradiate the conductive layer 2 formed on the opposite inner surface of the substrate 1 with the electromagnetic wave. The electromagnetic wave absorbing material 3 can prevent the electromagnetic wave from reaching the conductive layer 2 on the surface facing the conductive layer 2 that irradiates. Therefore, a circuit can be formed on the inner surface of the three-dimensional substrate 1 having an opposing surface by patterning by irradiation of an electromagnetic wave from the outside of the substrate 1, and the circuit can be easily formed by a patterning method using an electromagnetic wave. In addition, it can be performed with high accuracy.

  Hereinafter, the best mode for carrying out the present invention will be described.

  FIG. 1 and FIG. 2 show an example of an embodiment of the present invention, and as the base material 1, a three-dimensional shape having mutually opposing surfaces is used. In FIG. 1A and FIG. 2A, the base material 1 having the facing surface is exemplified by a cylindrical shape such as a cylindrical shape. For example, the present invention can also be applied to a U-shaped substrate 1.

  Moreover, as this base material 1, what is formed with the material which has an electrical insulation property and the property which permeate | transmits electromagnetic waves, such as a laser, is used, The material which has such an electrical insulation property and electromagnetic wave transparency Examples of the inorganic material include glass and quartz, and examples of the organic material include acrylic resin, polycarbonate, polystyrene, polycyclooxide, epoxy resin, and polyimide.

  First, the conductive layer 2 is formed on the surface of the opposing surface of the base material 1 on the inner peripheral surface of the base material 1 when the base material 1 has a cylindrical shape, as shown in FIGS. To form. The conductive layer 2 can be formed of a conductive material such as metal, and the conductive layer 2 can be formed by any method such as electroless plating such as electroless copper plating or DVD method such as sputtering. . Here, when the substrate 1 has a cylindrical shape such as a cylindrical shape where the opposing inner surfaces are closed, it is difficult to form the conductive layer 2 on the opposite surface of the substrate 1 by a DVD method such as sputtering. For example, the conductive layer 2 can be easily formed on the opposing inner surface of the substrate 1 by applying or immersing the electroless plating solution.

  After forming the conductive layer 2 on the opposing surface of the base material 1 as described above, between the opposing inner surfaces of the base material 1 (in the inner periphery of the base material 1 when the base material 1 is cylindrical), FIG. As shown in (c), the electromagnetic wave absorber 3 having the property of absorbing electromagnetic waves such as a laser is disposed. As the electromagnetic wave absorber 3, any material such as carbon can be used, but a fluid is desirable. For example, the electromagnetic wave absorbing material 3 can be formed by mixing a powder 3a formed of a material that absorbs electromagnetic waves into a gas or liquid and using a fluid containing the powder 3a. As the electromagnetic wave absorbing powder 3a, pigment powder, magnesium oxide powder, carbon powder or the like can be used. Alternatively, the fluid electromagnetic wave absorbing material 3 can be formed of dye water that absorbs electromagnetic waves having an irradiation wavelength. When the electromagnetic wave absorber 3 made of such a fluid is used for the base material 1 formed in a cylindrical shape, the opening ends of the pair of pipes 10a and 10b are connected to the base material 1 as shown in FIG. The pipes 10a and 10b are brought into close contact with the base material 1 with the packing 11 provided at the outer peripheral ends of the pipes 10a and 10b, respectively, in contact with the opening end surfaces on both sides. Then, after the electromagnetic wave absorbing material 3 is discharged from one pipe 10a, the electromagnetic wave absorbing material 3 is passed through the inner periphery of the base material 1, and then the electromagnetic wave absorbing material 3 is sucked into the other pipe 10b. The electromagnetic wave absorbing material 3 can be made to flow between the opposing surfaces.

  And the electromagnetic wave L is irradiated from the outer side of the base material 1 in the state which made the electromagnetic wave absorber 3 which consists of a fluid flow in one direction between the opposing surfaces of the base material 1. As the electromagnetic wave L, for example, a laser such as YAG-SHG having a wavelength of 532 nm or YAG-THG having a wavelength of 355 nm can be used. When the electromagnetic wave L is irradiated in this way, the electromagnetic wave L is transmitted through the electromagnetic wave transmissive substrate 1, so that the conductive layer 2 formed on the inner surface of the substrate 1 is irradiated with the electromagnetic wave L, and FIG. As shown in 2 (d), the portion of the conductive layer 2 irradiated with the electromagnetic wave L is removed. Irradiation of the electromagnetic wave L is performed by scanning along the outer shape of the circuit forming portion 4 which is a portion of the conductive layer 2 where the circuit 6 is formed, and the conduction of the non-circuit forming portion 5 where the circuit 6 is not formed. Layer 2 is removed. At this time, it is not necessary to remove the conductive layer 2 on the entire surface of the non-circuit forming portion 5, and the conductive layer 2 may be removed only at the boundary region between the circuit forming portion 4 and the non-circuit forming portion 5. Even if the conductive layer 2 remains in the circuit forming portion 5, the conductive layer 2 of the circuit forming portion 4 and the conductive layer 2 of the non-circuit forming portion 5 may be separated to ensure electrical insulation.

  Thus, by irradiating the electromagnetic wave L while scanning along the boundary region between the circuit forming part 4 and the non-circuit forming part 5, the circuit forming part 4 forming the circuit 6 can be patterned. By irradiating the electromagnetic wave L from the outside of the material 1, it is possible to perform highly accurate patterning on the three-dimensional solid surface of the substrate 1 without using a mask or the like.

  And when performing the patterning which permeate | transmits the base material 1 as mentioned above, and irradiates the electromagnetic wave L and removes the conductive layer 2 of the inner surface of the base material 1 partially, the electromagnetic wave L which permeate | transmitted the base material 1 further opposes. Although there is a possibility of irradiating the conductive layer 2 on the side, the electromagnetic wave absorbing material 3 is present between the opposing surfaces of the base material 1, so that the electromagnetic wave L that has passed through the base material 1 and removed the conductive layer 2 on the inner surface. Can be prevented from being absorbed by the electromagnetic wave absorber 3 as indicated by broken lines in FIGS. 1D and 2D and irradiating the conductive layer 2 on the opposite side of the electromagnetic wave L. Is.

  Further, when the conductive layer 2 is partially removed by irradiating the electromagnetic wave L, the conductive material is scattered inside the base material 1 by the removal of the conductive layer 2, but the opposing surface of the base material 1 as described above. When the electromagnetic wave L is irradiated in a state where the electromagnetic wave absorbing material 3 made of fluid is made to flow during the period, the scattered conductive material is discharged from the inside of the substrate 1 together with the flowing electromagnetic wave absorbing material 3 and taken out. It is possible to prevent the scattered conductive material from adhering to the surface of the circuit forming portion 5 or between the circuit forming portion 4 and the non-circuit forming portion 5 to cause insulation failure in the circuit 6. It is something that can be done.

  As described above, by patterning with the electromagnetic wave L, the circuit forming portion 4 can be formed with the conductive layer 2 on the opposing inner surface of the substrate 1, and this circuit forming portion 4 can be used as the circuit 6. When the conductive layer 2 is formed as a thin film, electroplating is performed by applying a direct current to the conductive layer 2 of the circuit forming portion 4 as shown in FIGS. 1 (e) and 2 (e). By forming the electroplating layer 12 on the surface of the conductive layer 2 of the circuit forming portion 4, the circuit 6 having a predetermined thickness can be finished.

  3 and 4 show another embodiment of the present invention. As the substrate 1, the same ones as described above can be used as shown in FIGS. 3 (a) and 4 (a), and the same as the above as shown in FIGS. 3 (b) and 4 (b). Thus, the conductive layer 2 can be formed on the opposing inner surface of the substrate 1. In this embodiment, as the electromagnetic wave absorbing material 3, a solid material formed in a columnar shape such as a cylinder with an electromagnetic wave absorbing material such as carbon is used, which is shown in FIGS. 3 (c) and 4 (c). As described above, the solid electromagnetic wave absorbing material 3 is inserted and disposed between the opposing inner surfaces of the base material 1 (inner circumference of the base material 1 when the base material 1 is cylindrical). At this time, it is desirable to form a gap between the inner surface of the substrate 1 and the electromagnetic wave absorber 3.

  Then, with the electromagnetic wave absorbing material 3 arranged between the opposing surfaces of the base material 1 as described above, the electromagnetic wave L is irradiated from the outside of the base material 1 as shown in FIGS. 3 (d) and 4 (d). The conductive layer 2 on the inner surface of the substrate 1 can be partially removed by the electromagnetic wave L that has passed through the material 1, and the conductivity of the boundary region between the circuit forming part 4 and the non-circuit forming part 5 is similar to the above. Patterning can be performed by removing the layer 2. Moreover, the electromagnetic wave L which permeate | transmitted the base material 1 and removed the conductive layer 2 of the inner surface is absorbed by the electromagnetic wave absorber 3 as shown with a broken line in FIG.3 (d) and FIG.4 (d), and this electromagnetic wave L opposes. It is possible to prevent the conductive layer 2 on the side to be irradiated from being irradiated. Further, as shown in FIGS. 3 (e) and 4 (e), by forming an electroplating layer 12 on the surface of the conductive layer 2 of the circuit forming portion 4 as described above, a circuit 6 having a predetermined thickness is obtained. It can be finished.

  As shown in FIG. 1 (e) and FIG. 2 (e) and FIG. 3 (e) and FIG. 4 (e), a solid body formed by providing a circuit 6 on the inner peripheral surface of the cylindrical substrate 1 is formed. The circuit board A can be used as a component such as a micro actuator, a micro electrostatic encoder, a micro electrostatic motor, or a micro pump. 5 (a) and 5 (b) show an example. The cylindrical base 1 is a stator 15, the inner circuit 6 of the base 1 is a fixed electrode 16, and the movable electrode 17 is provided on the outer periphery. A microactuator is formed by disposing a movable element 18 provided with a rotary shaft 19 inside a stator 15 so as to be freely rotatable.

An example of embodiment of this invention is shown, (a) thru | or (e) is side surface sectional drawing of each process of manufacture. An example of embodiment of this invention is shown, (a) thru | or (e) is front sectional drawing of each process of manufacture. The other example of embodiment of this invention is shown, (a) thru | or (e) is side sectional drawing of each process of manufacture. The other example of embodiment of this invention is shown, (a) thru | or (e) is front sectional drawing of each process of manufacture. An example of the microactuator using a three-dimensional circuit board is shown, (a) is side surface sectional drawing, (b) is front sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Conductive layer 3 Electromagnetic wave absorber 4 Circuit formation part 5 Non-circuit formation part 6 Circuit

Claims (5)

A conductive layer is formed on this facing surface of a three-dimensionally shaped electromagnetic wave-transmitting substrate with surfaces facing each other inside, and an electromagnetic wave absorbing material having the property of absorbing electromagnetic waves is placed between the facing surfaces of the substrate In this state, at least the boundary region between the circuit forming portion and the non-circuit forming portion that forms a circuit in the conductive layer while irradiating the conductive layer with the electromagnetic wave through the base material from the side opposite to the side on which the conductive layer is formed. A method for producing a three-dimensional circuit board, wherein the conductive layer is removed by irradiation with electromagnetic waves.   The method for producing a three-dimensional circuit board according to claim 1, wherein the conductive layer is formed by electroless plating.   3. The three-dimensional circuit board according to claim 1, wherein a fluid is used as the electromagnetic wave absorbing material, and the electromagnetic wave is irradiated in a state where the fluid is disposed between the opposing surfaces of the base material while being flowed. Method.   The method for producing a three-dimensional circuit board according to claim 3, wherein the electromagnetic wave absorbing material made of a fluid is a mixture of powder that absorbs electromagnetic waves in a gas or liquid.   A three-dimensional circuit board manufactured by the method according to claim 1.

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