JP2007150180A - Flexible circuit board and its production process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin circuit board excellent in flexibility on which various circuit components are formed, and to provide its production process. <P>SOLUTION: The flexible circuit board 10 comprises a flexible substrate 11, a wiring pattern 12 provided on at least one surface of the substrate 11, and a circuit component 15 formed integrally with the substrate 11 by filling a groove formed on one surface of the substrate 11 at a predetermined depth in a predetermined pattern with a predetermined material, wherein the wiring pattern 12 and the circuit component 15 are connected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flexible flexible circuit board on which circuit components are formed and a method for manufacturing the same.

  In recent years, with the speeding up of electronic devices, measures such as EMI (electromagnetic interference) and EMC (electromagnetic environment compatibility) that affect other electronic devices and the environment have become important. For example, when connecting a circuit board inside an electronic device, a flexible circuit board, which is a cable, becomes an antenna, and electromagnetic noise is radiated into and out of the electronic device, which becomes a serious problem.

  On the other hand, it is a thinner and more flexible flexible circuit board that can be used for "wearable computer systems" that can be worn on the body, as well as articles of various shapes and places where the curvature changes freely. Realization of is demanded.

  These flexible circuit boards are also required to have higher flexibility as well as prevention of electromagnetic noise.

  Therefore, in order to prevent electromagnetic noise, conventionally, a flexible circuit board has been mounted with a filter circuit as a countermeasure. The configuration is such that a chip capacitor is mounted as a filter element around a connector connected by a flexible circuit board, one electrode terminal is connected to the connector terminal, and the other electrode terminal is grounded.

  However, such a configuration requires a mounting space for mounting an electronic component such as a chip capacitor around the electronic component, which makes it extremely difficult to reduce the size and thickness of the electronic device. In addition, the electronic component was damaged and the connection reliability was low with respect to deformation such as bending.

  In order to improve these, as an alternative to a chip capacitor, a comb-shaped electrode is embedded in a printed wiring board facing in the depth direction, and a capacitor is provided in the substrate with a dielectric interposed between the pair of comb-shaped electrodes. An example is disclosed (for example, see Patent Document 1).

According to this, by incorporating a capacitor, a thin printed wiring board corresponding to measures such as EMI can be realized.
JP 2004-72034 A

  However, according to the printed wiring board disclosed in Patent Document 1 described above, the comb-shaped electrodes are formed so as to face each other in the depth direction of the dielectric, and the plate electrodes are formed on both surfaces of the dielectric to constitute the capacitor. is doing. For this reason, the shape of the comb electrode is limited by the thickness of the printed wiring board, and the range of the obtained capacitance is narrow.

  In addition, since the comb-shaped electrode is formed on the dielectric, there is a problem that flexibility is low and cracks are easily generated with respect to bending deformation and reliability is low.

  Moreover, since the comb-shaped electrode is formed by forming through holes or non-through holes at a plurality of positions in the depth direction of the dielectric, there is a problem in productivity.

  In addition, there is a problem that an arbitrary filter or the like that can be used for various applications without any description other than the capacitor cannot be configured.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a thin and excellent flexible circuit board on which various circuit components are formed, and a method for manufacturing the same.

  In order to solve the problems as described above, the flexible circuit board of the present invention includes a flexible substrate, a wiring pattern provided on at least one surface of the substrate, and a predetermined surface on one surface of the substrate. A circuit component formed by embedding a predetermined material in a groove formed in a predetermined pattern shape and integrated with a base material, and having a configuration in which the wiring pattern and the circuit component are connected.

  Furthermore, two or more different circuit components may be provided.

  Furthermore, the base material may have a conductive via, and the circuit component may be connected to the wiring pattern via the conductive via.

  Furthermore, the circuit component includes a comb-shaped electrode pair formed by embedding an electrode material as a predetermined material in a groove having a comb-shaped pattern formed oppositely, and a capacitor having a dielectric layer as a base material between the comb-shaped electrode pair It may be.

  Further, the circuit component may be an inductor formed by embedding a conductor material as a predetermined material in the groove.

  Further, the circuit component may be a register formed by embedding a resistor material as a predetermined material in the groove.

  By these, since various circuit components can be integrally formed by the groove | channel provided in the base material, the flexible circuit board excellent in the thinness and flexibility is realizable. Furthermore, the characteristics of the circuit components can be easily adjusted by the groove depth and pattern shape.

  The method for manufacturing a flexible circuit board of the present invention includes a step of forming a groove having a predetermined pattern shape with a predetermined depth on at least one surface of a base material made of a resin material, and a predetermined material for the groove. Embedding and integrating with the base material to form a circuit component, and forming a wiring pattern on at least one surface of the base material and connecting the wiring pattern and the circuit component.

  Furthermore, the step of forming a groove in the base material includes a step of pressing a mold having a convex portion having a predetermined pattern shape on one surface of the resin material to form a groove, and curing the resin material to form the base material. And a step of peeling the base material from the mold.

  Furthermore, the step of forming a groove in the base material includes a step of injecting a resin material into a mold having convex portions of a predetermined pattern shape, curing the resin material to form the base material, and forming the base material into a mold. And a step of peeling from the substrate.

  Furthermore, you may further include the process of forming a conductive via in a base material.

  Furthermore, the resin material may include any one of a thermoplastic resin, a thermosetting resin, and a photocurable resin.

  Furthermore, the circuit component is a capacitor in which a comb-shaped electrode pair is formed by embedding an electrode material as a predetermined material in a groove having an opposing comb-shaped pattern shape, and a base material between the comb-shaped electrode pairs is formed as a dielectric layer. May be.

  Furthermore, the circuit component may be an inductor formed by embedding a conductive material as a predetermined material in a groove having a predetermined pattern shape.

  Furthermore, the circuit component may be a register formed by embedding a resistor material as a predetermined material in a groove having a predetermined pattern shape.

  By these methods, since various circuit components can be integrally formed with the grooves provided in the base material, a thin and flexible flexible circuit board can be produced with high productivity.

  The flexible circuit board of the present invention is a flexible resin substrate having a wiring pattern on at least one surface, and a predetermined pattern shape having a predetermined height formed on the resin substrate with a predetermined material. The circuit component and the circuit component are provided with at least an embedded resin layer, and the wiring pattern and the circuit component are connected to each other.

  Furthermore, two or more different circuit components may be provided.

  Furthermore, the resin substrate may have a conductive via, and the circuit component may be connected to the wiring pattern via the conductive via.

  Further, the circuit component may be a capacitor having a comb-shaped electrode pair formed in a comb-shaped pattern with an electrode material as a predetermined material, and a dielectric layer formed by embedding a dielectric material between the comb-shaped electrode pairs. .

  Furthermore, the dielectric layer may be a resin layer.

  Furthermore, the circuit component may be an inductor having a predetermined pattern shape made of a conductive material as a predetermined material.

  Further, the circuit component may be a register having a predetermined pattern shape made of a resistor material as a predetermined material.

  Accordingly, it is possible to realize a flexible circuit board that can easily adjust the characteristics of the circuit components according to the pattern shape and height. In particular, a capacitor which is a circuit component can easily expand the capacitance range because an arbitrary dielectric material can be used as a dielectric layer between comb-shaped electrode pairs.

  Further, a circuit board may be provided in a stacked manner.

  Thereby, a flexible circuit board having various circuit configurations can be easily realized.

  The method for manufacturing a flexible circuit board according to the present invention includes a step of forming a wiring pattern on at least one surface of a flexible resin substrate, and a resin substrate having a predetermined height and a predetermined pattern shape. A step of forming a circuit component connected to the wiring pattern with a predetermined material and a step of forming a resin layer at least up to the height of the circuit component are included.

  Further, in the step of forming circuit components on the resin substrate, a circuit in which a mold having a predetermined pattern shape and a predetermined material embedded in a groove having a predetermined depth is arranged at the position of the wiring pattern formed on the resin substrate. You may include the process of forming components, and the process of peeling a circuit component from a metal mold | die.

  Furthermore, a step of forming a conductive via in the resin substrate may be further included.

  By these methods, the mounting surface of the circuit component can be flattened by the resin layer, so that a flexible circuit board with an easy laminated structure can be manufactured. Furthermore, since the capacitor, which is one of the circuit components, can be formed by arbitrarily selecting the dielectric material of the dielectric layer, it is possible to produce a flexible circuit board that can further easily design the filter characteristics.

  According to the flexible circuit board and the manufacturing method thereof of the present invention, it is possible to realize a thin and flexible flexible circuit board on which various circuit components are formed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, for easy explanation, the drawings are arbitrarily enlarged.

  In each of the following embodiments, a flexible circuit board having a filter circuit composed of a capacitor, an inductor, and a resistor will be described as an example, but it goes without saying that the present invention is not limited to this.

(First embodiment)
Hereinafter, the flexible circuit board according to the first embodiment of the present invention will be described with reference to FIG.

  1A is a plan view showing a flexible circuit board according to the first embodiment of the present invention, FIG. 1B is a cross-sectional view taken along the line AA of FIG. 1A, and FIG. It is BB sectional drawing of the same figure (a).

  As shown in FIG. 1, the flexible circuit board 10 has a predetermined pattern with a predetermined depth on one surface of a base material 11 made of polyethylene terephthalate (PET) having a thickness of, for example, 100 μm to 1000 μm. A circuit component 15 is formed by embedding a predetermined material in each groove formed in a shape. The circuit component 15 includes at least one of a capacitor (C) 16, an inductor (L) 17, and a resistor (R) 18, as will be described in detail below. Hereinafter, a capacitor may be abbreviated as C, an inductor as L, and a resistor as R, if necessary.

  Furthermore, the wiring pattern 12 and the conductive via 19 are formed on the base material 11 by using, for example, screen printing with a conductive resin containing silver particles or the like, and a filter circuit is configured by L, C, and R, for example. By connecting to the circuit component 15, the flexible circuit board 10 is formed. Further, if necessary, a protective layer (not shown) such as a resist may be provided in order to protect the circuit component 15 and the wiring pattern 12 except for the connection terminal 13 connected to an external device.

  In the first embodiment, the configuration of the filter circuit in which the wiring pattern 12 and all the circuit components 15 including L, C, and R are connected has been described. However, the present invention is not limited to this. For example, a configuration of a filter circuit including, for example, an LC filter or an RC filter, which includes at least a capacitor, among the circuit components 15 including three types of L, C, and R may be used. Furthermore, it goes without saying that a plurality of L, C, and R may be formed individually.

  Here, as the wiring pattern 12, in addition to the above method, for example, a patterned metal foil or plating film of copper or aluminum can be used.

  Below, the circuit component 15 which comprises the flexible circuit board 10 in the 1st Embodiment of this invention is demonstrated.

  First, the capacitor 16 that is one of the circuit components 15 will be described.

  As shown in FIG. 1, the capacitor 16 has a depth t in a comb-like pattern shape having a length W, a distance d1, an electrode width d2, and the number of combs f (shown by five in the drawing) on the surface of the substrate 11. The groove is filled with an electrode material such as a conductive resin containing copper (Cu) particles, for example, and has a comb-shaped electrode pair 163 formed by facing comb-shaped electrodes 161 and 162. Then, as shown in FIG. 1C, the capacitor 16 is configured with the base material 11 between the comb-shaped electrode pair 163 as a dielectric layer. Here, the capacitance of the capacitor 16 is the length W of the comb-shaped electrodes 161 and 162, the electrode width d2, the depth t, the number of combs f, the distance d1 between the comb-shaped electrode pairs 163, and the dielectric layer between the comb-shaped electrode pairs 163. It can be designed to an arbitrary value according to each parameter such as the dielectric constant ε of the substrate 11.

  As a result, the capacitor constituted by the comb-shaped electrodes can realize a wide capacitance range, and can realize a capacitor excellent in reliability that is less likely to cause a short circuit than a capacitor formed by stacking in the thickness direction.

  Next, the inductor 17 that is one of the circuit components 15 will be described.

  As shown in FIG. 1A, the inductor 17 has a predetermined shape, for example, a conductive pattern such as a conductive resin containing copper particles or the like in a groove having a predetermined depth in a spiral or ring-shaped pattern shape. Constructed by filling body material. The inductor 17 having an arbitrary inductance can be realized by the number of turns of the formed pattern, the cross-sectional area, the length, the magnetic permeability of the conductor material, and the like.

  Next, the register 18 that is one of the circuit components 15 will be described.

  As shown in FIG. 1A, the register 18 includes, for example, a copper nickel alloy, conductive carbon particles, or the like in a groove having a predetermined shape, for example, a rectangular or linear pattern shape and having a predetermined depth. It is configured by filling a resistor material. The resistor 18 having an arbitrary resistance value can be easily realized by the cross-sectional area defined by the length and width of the formed pattern and the depth of the groove, the resistivity of the resistor material, and the like.

  With the above configuration, a flexible circuit board 10 is obtained in which circuit parts such as L, C, and R are made of an optimal material on the same base material and are integrally formed.

  According to the first embodiment of the present invention, various circuit components can be integrally formed by filling a flexible substrate with a predetermined material in a predetermined pattern and a predetermined depth. Thus, a flexible circuit board that is thin and excellent in flexibility can be realized.

  Further, since the pattern shape and depth of each circuit component can be arbitrarily set, a flexible circuit board capable of freely designing necessary characteristic values can be easily obtained.

  Moreover, arbitrary combinations are possible by selecting and connecting connection terminals of circuit components made of L, C, and R formed on the substrate. As a result, for example, a flexible circuit board with excellent versatility that can form an arbitrary filter circuit can be realized.

  Below, the manufacturing method of the flexible circuit board in the 1st Embodiment of this invention is demonstrated using FIG.

  2 (a) to 2 (f) are process cross-sectional views illustrating a method for manufacturing a flexible circuit board according to the first embodiment of the present invention, and FIG. 2 (g) is a plan view of FIG. 2 (f). It is.

  First, as shown in FIG. 2A, a mold 20 having a convex portion 21 for forming a groove having a predetermined pattern shape and a predetermined depth to be various circuit components on a base material is prepared. . At this time, the convex portions 211 and 212 at least one end of the pattern forming the inductor and the capacitor are formed with a height similar to the thickness of the base material described below.

  Next, as shown in FIG. 2B, a resin material 22 such as PET, which is a base material, is poured into the mold 20 to the height of the convex portions 211 and 212, for example, while being heated and filled. . Thereafter, the resin material 22 is cooled and cured. At this time, it is preferable to apply, for example, a silicone release agent, a fluorine release agent, or the like to the mold 20 in order to improve the release property.

  Here, as the resin material to be a base material, in addition to the above PET, a resin or a composite material including any one of a thermoplastic resin, a thermosetting resin, and a photocurable resin can be used. . Then, they can be cured by heating, light irradiation such as ultraviolet rays, or a combination thereof. As the thermoplastic resin, methacrylic acid resin, polypropylene, polyvinylidene fluoride, acrylic, polycarbonate, or the like can be used. Further, as the thermosetting resin, epoxy, phenol resin, polyimide, polyphenylene sulfide, unsaturated polyester resin, melamine resin, urea resin, or the like can be used. Furthermore, acrylic modified resin etc. can be used as photocurable resin.

  Next, as shown in FIG. 2C, the cured resin material 22 is peeled from the mold 20. Thereby, the base material 11 in which the groove | channel 23 which consists of predetermined pattern shape and predetermined depth in which each circuit component is formed in a predetermined position is produced. For example, when the circuit component is a capacitor, a groove 231 having a predetermined depth in a comb pattern is formed in the base material 11. When the circuit component is an inductor, a groove 232 having a predetermined depth is formed in the substrate 11 in a spiral pattern shape. Further, when the circuit component is a register, a groove 233 having a rectangular pattern shape and a predetermined depth is formed in the base material 11.

  Next, as shown in FIG. 2D, a predetermined material is filled into each groove 231, 232, 233 for each circuit component by using, for example, screen printing.

  Here, the predetermined material is an electrode material paste 241 in the case of a capacitor, a conductor material paste 242 in the case of an inductor, and a resistor material paste 243 in the case of a resistor. The electrode material paste 241 may be a paste obtained by mixing metal particles such as copper, silver, aluminum, nickel, gold, palladium, tin, alloy particles thereof, conductive carbon particles, and a binder resin. . Further, as the conductor material paste 242, it is possible to use metal particles such as silver, copper, aluminum, nickel, gold, palladium, and tin, alloy particles thereof, conductive carbon particles, or the like mixed with a binder resin. it can. Further, as the resistor material paste 243, a paste obtained by mixing a copper nickel alloy, conductive carbon particles, and a binder resin can be used. Note that the binder resin of each paste is preferably the same material in consideration of conditions such as the curing temperature. Moreover, a thing with little cure shrinkage is preferable. Furthermore, the thing lower than the glass transition temperature of the base material 11 is especially preferable.

  Next, as shown in FIG.2 (e), the said predetermined material is hardened on the conditions below the glass transition temperature of the base material 11, for example, 120 degreeC and 60 minutes. As a result, the capacitor 16, the circuit component 15 such as the inductor 17 and the resistor 18, and the conductive via 19 are formed using the base material 11 between the pair of comb-shaped electrodes 163 as a dielectric layer.

  In addition, since the base material 11 can be a dielectric layer, the capacitor 16 can be manufactured by selecting an insulating material having a desired dielectric constant as the base material 11.

  In the case where a predetermined material constituting the capacitor 16, the inductor 17, and the resistor 18 has a large amount of curing shrinkage, after curing the predetermined material, for example, both surfaces of the substrate 11 are polished to expose the predetermined material. May be. Thereby, the connection with the wiring pattern described below can be facilitated, and the connection reliability can be improved.

  Next, as shown in FIG. 2F, the wiring pattern 12 connected to the circuit component 15 formed on the substrate 11 is formed with a conductive paste, for example, using screen printing. Thereby, the circuit component 15 and the conductive via 19 are connected by the wiring pattern 12 to produce the flexible circuit board 10.

  The wiring pattern 12 is formed by attaching a metal foil such as copper or aluminum to the surface of the substrate 11, and then etching and patterning, or plating a metal film on the patterned conductive layer. May be.

  And as shown in FIG.2 (g), the flexible circuit which functions as various filter circuits, such as LC filter, RC filter, LCR filter, etc. by selecting the connection terminal 13 of the wiring pattern 12 formed in the base material 11, for example. A substrate 10 is obtained.

  According to the manufacturing method of the first embodiment of the present invention, a flexible circuit board including circuit components having arbitrary characteristic values on the same base material according to selection of a predetermined material, pattern shape, and groove depth Can be produced.

  Moreover, since various circuit components can be integrally formed with the pattern shape of the grooves formed on the base material collectively by the mold, a thin flexible circuit board can be produced with high productivity.

  Various filter circuits can be configured by arbitrarily selecting the connection terminals.

  Further, since an expensive manufacturing apparatus such as a sputtering apparatus or a CVD apparatus is not required, it is inexpensive and can be formed at a low temperature, so that a flexible circuit board with significantly improved productivity can be realized.

  Hereinafter, another example of the method for manufacturing the flexible circuit board according to the first embodiment of the present invention will be described with reference to FIG.

  FIG. 3 is a process cross-sectional view illustrating another example of the method for manufacturing the flexible circuit board in the first embodiment of the present invention. 3 corresponds to the steps from FIG. 2A to FIG. 2C, and the subsequent steps are the same as those from FIG. 2D to FIG. 2G. That is, in another example of the manufacturing method of the present embodiment, the step of forming a groove in the base material is different from that of the first embodiment.

  That is, first, as shown in FIG. 3A, a mold 30 is prepared in which a convex portion 31 for forming a groove having a predetermined pattern shape and a predetermined depth of each circuit component is formed on a base material. . At this time, the convex portions 311 and 312 at the ends of at least one of the patterns forming the inductor and the capacitor are formed to have the same height as the thickness of the base material described below.

  Next, as shown in FIG. 3B, a resin film 33 such as PET having a thickness of at least 100 μm to 1000 μm, for example, having an outer wall at least as high as the heights of the convex portions 311 and 312 is provided. A mold 32 is prepared.

  Next, as shown in FIG. 3C, the convex portion 31 of the mold 30 is pressed against the resin film 33 of the mold 32 to transfer the shape of the convex portion 31 to the resin film 33. For example, when the resin film 33 is a thermoplastic resin, the resin film 33 is heated to the glass transition temperature or higher, and the shape of the convex portion 31 of the mold 30 is transferred to the surface thereof. In the case of a thermosetting resin, the mold 30 is pressed to the resin film 33 and heated to the curing temperature to transfer the shape of the convex portion 31. In the case of a photocurable resin, the mold 30 is pressed against the resin film 33 and cured by UV (ultraviolet) irradiation, and the shape of the convex portion 31 is transferred.

  At this time, it is preferable to press the convex portions 311 and 312 of the mold 30 until they contact the inner bottom surface of the mold 32 to form a through hole in the resin film 33. However, when the through hole cannot be formed, a polishing step may be provided to form the through hole.

  Then, as shown in FIG. 3 (d), the molds 30, 32 are peeled from the cured resin film, and the bases having grooves 231, 232, 233 each having a predetermined pattern and depth corresponding to each circuit component. Material 11 is produced.

  The subsequent steps are the same as those shown in FIGS. 2D to 2G, and a description thereof will be omitted.

  In addition, although the resin film was demonstrated to the example above, it is not restricted to this. For example, a resin material such as a thermoplastic resin having fluidity, a thermosetting resin, or a photocurable resin may be used.

  By this method, a film or the like can be used as the resin material. As a result, it is not necessary to adjust and manage the viscosity as in the case of a resin material having fluidity, and the handling becomes easy, so that a flexible circuit board with higher productivity can be manufactured.

(Second Embodiment)
The flexible circuit board according to the second embodiment of the present invention will be described below with reference to FIG.

  FIG. 4A is a plan view showing a flexible circuit board according to the second embodiment of the present invention, and FIG. 4B is a cross-sectional view taken along the line AA of FIG.

  As shown in FIG. 4, the flexible circuit board 40 includes a resin substrate 41 made of polyethylene terephthalate (PET) having a thickness of, for example, 200 μm and provided with conductive vias 50 and wiring patterns 49. Corresponding to a predetermined position of the wiring pattern 49, a circuit component 45 formed of a predetermined material with a predetermined pattern shape and a predetermined height is provided. Here, as described in detail below, the circuit component 45 includes at least one of a capacitor (C) 46, an inductor (L) 47, and a resistor (R) 48. Further, if necessary, at least the connection terminals 44 of the wiring pattern 49 are exposed, and at least the circuit component 45 is embedded or the resin layer 42 made of polyester or the like covering the circuit component 45 is provided to flatten the surface. Thus, the flexible circuit board 40 is formed.

  The resin layer 42 may be provided only between the comb-shaped electrode pairs when the circuit component 45 described below is the capacitor 46. In particular, the resin layer 42 may not be provided if the surface is not required to be planarized. In this case, the air layer of the capacitor 46 is a dielectric layer.

  Here, as the material of the resin substrate 41 and the wiring pattern 49, the same materials as those in the first embodiment can be used.

  In the second embodiment, the configuration of the filter circuit in which the wiring pattern 49 and all the circuit components 45 including L, C, and R are connected has been described. However, the present invention is not limited to this. For example, it is good also as a structure of the filter circuit which consists of LC filter, RC filter, etc. which contain at least a capacitor among the circuit components 45 which consist of 3 types of L, C, and R. Furthermore, it goes without saying that a plurality of L, C, and R may be formed individually.

  Below, the circuit component 45 which comprises the flexible circuit board 40 in the 2nd Embodiment of this invention is demonstrated.

  First, the capacitor 46 which is one of the circuit components 45 will be described.

  As shown in FIG. 4, the capacitor 46 has a height t in the shape of a comb pattern having a length W, a distance d1, an electrode width d2, and the number of combs f (shown by five in the drawing) on the resin substrate 41. For example, an electrode material such as a conductive resin containing copper (Cu) particles or the like is used to have a comb-shaped electrode pair 463 in which comb-shaped electrodes 461 and 462 are formed to face each other. Then, as shown in FIG. 4B, the capacitor 46 is configured with the resin layer 42 between the comb electrode pairs 463 as a dielectric layer 464. Here, the capacitance of the capacitor 46 includes the length W of the comb-shaped electrodes 461 and 462, the electrode width d2, the height t, the number f of combs, the distance d1 between the comb-shaped electrode pairs 463, and the dielectric layer embedded between the comb-shaped electrode pairs 463. An arbitrary value can be designed by each parameter such as the dielectric constant ε of 464. The dielectric layer 464 can realize the capacitor 46 whose capacitance value can be freely designed by selecting an arbitrary material having a high dielectric constant such as barium titanate or lead titanate. Further, the air layer may be a dielectric layer without forming the resin layer 42.

  Next, the inductor 47 that is one of the circuit components 45 will be described.

  As shown in FIG. 4A, the inductor 47 is made of a conductive material such as a conductive resin having a predetermined shape, for example, a spiral or ring-shaped pattern and having a predetermined height, for example, including copper particles. It is formed. An inductor 47 having an arbitrary inductance can be realized by the number of turns of the formed pattern, the cross-sectional area, the length, the magnetic permeability of the conductor material, and the like.

  Next, the register 48 that is one of the circuit components 45 will be described.

  As shown in FIG. 4A, the resistor 48 is a resistor material having a predetermined shape, for example, a rectangular or linear pattern shape and having a predetermined height, for example, a copper nickel alloy, conductive carbon particles, or the like. Formed with. The register 48 having an arbitrary resistance value can be easily realized by the cross-sectional area defined by the length and width of the formed pattern and the depth of the groove and the resistivity of the resistor material.

  According to the second embodiment of the present invention, the capacitance range can be further expanded by a capacitor having a dielectric layer made of any dielectric material from air between at least the comb-shaped electrode pairs. A flexible circuit board having characteristics can be realized.

  Moreover, by covering the surface of each circuit component with a resin layer, moisture resistance, oxidation of a predetermined material, and the like can be prevented, and reliability can be further improved.

  In addition, since the circuit component is formed after the wiring pattern and the conductive via are formed, a flexible circuit board excellent in connection reliability that is not affected by curing shrinkage of a predetermined material constituting each circuit component can be obtained.

  Below, the manufacturing method of the flexible circuit board in the 2nd Embodiment of this invention is demonstrated using FIG. 5 and FIG.

  5 (a) to 5 (f) are process cross-sectional views illustrating a method for manufacturing the flexible circuit board 40 in the second embodiment of the present invention, and FIG. 5 (g) is a plan view of FIG. 5 (f). FIG. FIG. 6A is a perspective view showing an example of a mold for forming an inductor which is a circuit component in the second embodiment of the present invention, and FIG. 6B is a mold for forming a capacitor which is a circuit component. FIG. 4C is a perspective view showing an example of a mold for forming a register which is a circuit component.

  First, as shown in FIG. 5A, a wiring pattern 49 is formed with a conductive resin containing silver particles at a predetermined position of a flexible resin substrate 41 made of, for example, a polyimide resin by using, for example, screen printing. And the conductive via 50 is formed.

  Next, as shown in FIG. 5 (b), a predetermined material is applied to the dies 51, 52, 53 having a predetermined pattern shape and a predetermined depth shown in FIGS. 6 (a) to 6 (c). For example, the grooves 541, 543, and 545 are filled using a squeegee. At this time, for example, a silicone-based mold release agent, a fluorine-type mold release agent, or the like may be applied to the molds 51, 52, 53 in order to further improve the mold release property.

  Here, in the case of the mold 51 constituting the inductor, the predetermined material is, for example, a conductor material paste 542 containing a mixture of copper particles and a binder resin. In the case of the mold 52 constituting the capacitor, for example, an electrode material paste 544 containing a mixture of copper (Cu) particles and a binder resin. Further, in the case of the mold 53 constituting the register, for example, a resistor material paste 546 containing a mixture of copper nickel alloy particles and a binder resin.

  Further, the molds 51, 52, and 53 shown in FIG. 5 can be formed by using a metal mold formed in a pattern shape of each circuit component, for example, by using an imprint method or a casting method on a transfer mold resin. Specifically, it is formed by pouring a transfer type resin such as a thermosetting silicone resin into a metal mold and curing it at a temperature of 150 ° C. for 0.5 hours. Thereby, the metal mold | die rich in flexibility can be formed.

  Next, as shown in FIG. 5C, the molds 51, 52, 53 filled with a predetermined material are placed so as to correspond to the predetermined positions of the wiring pattern 49 formed on the resin substrate 41. A predetermined material is cured at once. At this time, the wiring pattern 49 and the circuit component 45 are electrically connected simultaneously.

  Next, as shown in FIG. 5 (d), the molds 51, 52, and 53 are peeled from the surface of the resin substrate 41, and the inductor pattern 471, the comb-shaped electrode pair 463, and the register pattern 481 are transferred to the resin substrate 41.

  Through the above steps, a flexible circuit board 440 having a circuit component 45 such as a capacitor having an air layer as a dielectric layer is manufactured.

  Furthermore, in order to form a dielectric layer made of an arbitrary material on a resin layer or a capacitor that protects the surface of the inductor or resistor, the steps shown in FIG.

  That is, as shown in FIG. 5E, a resin layer 42 such as PET, which covers the inductor pattern 471 and the resistor pattern 481 transferred to the resin substrate 41 and fills the space between the comb-shaped electrode pairs 463 serving as a capacitor, is formed. For example, it is formed using screen printing. At this time, the connection terminal 44 connected to the external device of the wiring pattern 49 is formed to be exposed. In the case of the above configuration, the resin layer 42 serves as the dielectric layer 464 of the capacitor, but it goes without saying that the resin layer 42 may be formed only between the comb-shaped electrode pair 463 of the capacitor.

  Further, as the dielectric layer 464 of the capacitor, a high dielectric constant resin material in which particles such as barium titanate and lead titanate are mixed may be filled between the comb-shaped electrode pair 463. Thereby, the capacitor 46 having an arbitrary capacitance can be configured by selecting the material of the dielectric layer 464.

  Next, as shown in FIG. 5F, the resin layer 42 and the dielectric layer 464 are cured, for example, at 120 ° C. for 0.5 hours.

  Thereby, the flexible circuit board 40 excellent in reliability in which the circuit component 45 is protected by the resin layer 42 and the dielectric layer 464 is manufactured.

  And as shown in FIG.5 (g), the flexible circuit which functions as various filter circuits, such as LC filter, RC filter, and LCR filter, by selecting the connection terminal 44 of the wiring pattern 49 formed in the resin substrate 41, for example. A substrate 40 is obtained.

  According to the manufacturing method of the second embodiment of the present invention, since the height of the wiring pattern constituting various circuit components is not limited by the thickness of the resin substrate or the like, the flexible circuit substrate having a wide design range such as its characteristic value Can be realized.

  In addition, since any material can be selected as the dielectric layer of the circuit component including the capacitor in particular, a capacitor having a wide capacitance range can be easily manufactured, and a highly versatile flexible circuit board can be obtained.

  Hereinafter, another example of the flexible circuit board according to the second embodiment of the present invention will be described with reference to FIG.

  FIG. 7A is a cross-sectional view showing a configuration of another example 1 of the flexible circuit board according to the second embodiment of the present invention, and FIG. 7B shows the flexible circuit board according to the second embodiment of the present invention. It is sectional drawing which shows the structure of another Example 2 of a circuit board.

  A flexible circuit board 70 in FIG. 7A is different from the flexible circuit board 40 shown in FIG. 4 in that at least a capacitor, which is one of circuit components, is stacked.

  That is, as shown in FIG. 7A, the flexible circuit board 70 is the same as at least the comb-shaped electrode pair 463 of the capacitor 46 of the resin substrate 41 on which the capacitor 46, the inductor 47, and the resistor 48 are formed as circuit components. A capacitor 76 composed of a comb-shaped electrode pair 763 having a pattern shape is stacked. Then, a dielectric layer 764 made of a predetermined material is filled between the comb electrode pairs 763 as necessary. The dielectric layer 764 of the capacitor 76 may be the same dielectric material as the dielectric layer 464 of the capacitor 46, or may be different.

  According to another example 1 of the present embodiment, it is possible to realize a flexible circuit board in which the capacitance range is further expanded by increasing the facing area of the comb electrode pair.

  Further, the flexible circuit board 80 of FIG. 7B is different from the flexible circuit board 40 shown in FIG. 4 in that the circuit parts made of, for example, L, C, and R are laminated.

  That is, as shown in FIG. 7B, the flexible circuit board 80 is formed with, for example, a capacitor 46, an inductor 47, and a resistor 48 as circuit components, and the surface thereof is covered with a resin layer 42 with flatness. In addition, for example, a capacitor 76, an inductor 77, and a resistor 78 are formed to form a laminated structure. In this case, the capacitors 46 and 76 may be configured such that the comb electrode pairs 463 and 763 are connected to each other so as to function as one capacitor, or separated by the resin layer 42.

  According to another example 2 of the present embodiment, a thin and flexible circuit board having a plurality of circuit configurations can be realized.

  As described above, the flexible circuit board according to each embodiment of the present invention is thin and flexible that can be used for “wearable computer system”, articles having various shapes, and places where the curvature freely changes. A flexible circuit board with excellent versatility and high versatility can be realized.

  In particular, since the flexible circuit board according to each embodiment of the present invention can realize a circuit configuration having a filter function, it has a great effect on a wiring cable provided with a filter circuit resistant to electromagnetic noise.

  In each embodiment of the present invention, a circuit configuration including an inductor, a capacitor, and a resistor has been described. However, the present invention is not limited to this. For example, a flexible circuit board having a plurality of the same circuit components may be used. Thereby, since the same circuit component can be formed in an array, for example, a flexible circuit board that can be connected corresponding to each terminal such as a connector can be obtained.

  According to the flexible circuit board and the manufacturing method thereof of the present invention, it is useful as a circuit board of an electronic device in which functions such as a noise filter are required in addition to being thin and flexible.

(A) The top view which shows the flexible circuit board in the 1st Embodiment of this invention (b) The sectional view on the AA line of the figure (a) (c) The sectional view on the BB line of the figure (a) Process drawing explaining the manufacturing method of the flexible circuit board in the 1st Embodiment of this invention Process sectional drawing explaining another Example of the manufacturing method of the flexible circuit board in the 1st Embodiment of this invention (A) Top view which shows the flexible circuit board in the 2nd Embodiment of this invention (b) The sectional view on the AA line of the same figure (a) Process drawing explaining the manufacturing method of the flexible circuit board in the 2nd Embodiment of this invention (A) Perspective view showing an example of a mold for forming an inductor as a circuit component in the second embodiment of the present invention (b) Example of a mold for forming a capacitor as a circuit component in the same embodiment The perspective view which shows the example of the metal mold | die which forms the register | resistor which is a circuit component in the same embodiment (c) (A) Sectional drawing which shows the structure of another Example 1 of the flexible circuit board in the 2nd Embodiment of this invention (b) Another Example 2 of the flexible circuit board in the 2nd Embodiment of this invention Sectional view showing the configuration of

Explanation of symbols

10, 40, 70, 80, 440 Flexible circuit board 11 Base material 12, 49 Wiring pattern 13, 44 Connection terminal 15, 45 Circuit component 16, 46, 76 Capacitor (C)
17, 47, 77 Inductor (L)
18, 48, 78 Register (R)
19, 50 Conductive via 20, 30, 32, 51, 52, 53 Mold 21, 31, 211, 212, 311, 312 Protrusion 22 Resin material 23, 231, 232, 233, 541, 543, 545 Groove 33 Resin Film 41 Resin substrate 42 Resin layer 161, 162, 461, 462 Comb electrode 163, 463, 763 Comb electrode pair 241, 544 Electrode material paste 242, 542 Conductor material paste 243, 546 Resistor material paste 464, 764 Dielectric layer 471 Inductor pattern 481 Register pattern

Claims (25)

A flexible substrate;
A wiring pattern provided on at least one surface of the substrate;
A circuit component formed by embedding a predetermined material in a groove having a predetermined depth on one surface of the base material and having a predetermined pattern shape; and
A flexible circuit board, wherein the wiring pattern and the circuit component are connected. The flexible circuit board according to claim 1, wherein two or more different circuit components are provided. The flexible circuit board according to claim 1, wherein the base member has a conductive via, and the circuit component is connected to the wiring pattern via the conductive via. The circuit component includes a comb-shaped electrode pair formed by embedding an electrode material as the predetermined material in the groove having a comb-shaped pattern formed opposite to each other, and the base material between the comb-shaped electrode pair is a dielectric layer. The flexible circuit board according to claim 1, wherein the flexible circuit board is a capacitor. 4. The flexible circuit board according to claim 1, wherein the circuit component is an inductor formed by embedding a conductor material as the predetermined material in the groove. 5. 4. The flexible circuit board according to claim 1, wherein the circuit component is a resistor formed by embedding a resistor material as the predetermined material in the groove. 5. Forming a groove having a predetermined pattern shape at a predetermined depth on at least one surface of a base material made of a resin material;
A step of embedding a predetermined material in the groove and integrating the base material to form a circuit component;
Forming a wiring pattern on at least one surface of the substrate, and connecting the wiring pattern and the circuit component;
A method for manufacturing a flexible circuit board, comprising: Forming the groove in the substrate;
A step of pressing a mold having convex portions of the predetermined pattern shape on one surface of a resin material to form the groove, and curing the resin material to form the base material;
Peeling the base material from the mold;
The manufacturing method of the flexible circuit board of Claim 7 characterized by the above-mentioned. Forming the groove in the substrate;
Injecting a resin material into a mold having convex portions of the predetermined pattern shape, and curing the resin material to form the base material;
Peeling the base material from the mold;
The manufacturing method of the flexible circuit board of Claim 7 characterized by the above-mentioned. The method for manufacturing a flexible circuit board according to claim 7, further comprising a step of forming a conductive via in the base material. 11. The flexible circuit board according to claim 7, wherein the resin material includes any one of a thermoplastic resin, a thermosetting resin, and a photocurable resin. Manufacturing method. The circuit component is formed with a comb-shaped electrode pair formed by embedding an electrode material as the predetermined material in the groove having an opposing comb-shaped pattern shape, and the base material between the comb-shaped electrode pairs is formed as a dielectric layer. The method for manufacturing a flexible circuit board according to claim 7, wherein the method is a capacitor. 8. The method of manufacturing a flexible circuit board according to claim 7, wherein the circuit component is an inductor formed by embedding a conductor material as the predetermined material in the groove having the predetermined pattern shape. The method of manufacturing a flexible circuit board according to claim 7, wherein the circuit component is a resistor formed by embedding a resistor material as the predetermined material in the groove having the predetermined pattern shape. A flexible resin substrate provided with a wiring pattern on at least one surface;
A circuit component having a predetermined height and a predetermined pattern shape formed of a predetermined material on the resin substrate;
The circuit component includes at least a resin layer to be embedded,
A flexible circuit board, wherein the wiring pattern and the circuit component are connected. The flexible circuit board according to claim 15, wherein two or more different circuit components are provided. The flexible circuit board according to claim 15, wherein the resin substrate has a conductive via, and the circuit component is connected to the wiring pattern via the conductive via. The circuit component is a capacitor having a comb-shaped electrode pair formed of an electrode material as the predetermined material in a comb-shaped pattern and a dielectric layer formed by embedding a dielectric material between the comb-shaped electrode pair. The flexible circuit board according to claim 15, wherein the flexible circuit board is characterized in that: The flexible circuit board according to claim 18, wherein the dielectric layer is the resin layer. The flexible circuit board according to any one of claims 15 to 17, wherein the circuit component is an inductor having the predetermined pattern shape formed of a conductive material as the predetermined material. The flexible circuit board according to any one of claims 15 to 17, wherein the circuit component is a register having the predetermined pattern shape formed of a resistor material as the predetermined material. The flexible circuit board according to any one of claims 15 to 17, wherein the circuit boards are provided in a stacked manner. Forming a wiring pattern on at least one surface of a flexible resin substrate;
Forming a circuit component connected to the wiring pattern with a predetermined material having a predetermined height and a predetermined pattern on the resin substrate;
Forming a resin layer at least up to the height of the circuit component;
A method for manufacturing a flexible circuit board, comprising: Forming the circuit component on the resin substrate,
A step of forming a circuit component by disposing a mold in which a predetermined material is embedded in a groove having a predetermined depth in a predetermined pattern shape at a position of the wiring pattern formed on the resin substrate;
Peeling the circuit component from the mold;
The method for manufacturing a flexible circuit board according to claim 23, comprising: The method for manufacturing a flexible circuit board according to claim 23, further comprising a step of forming a conductive via in the resin substrate.

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