JP2006324542A - Printed wiring board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed wiring board excellent in heat-dissipation functional characteristics and high-current characteristics that can be manufactured with a small number of steps, and to provide its manufacturing method. <P>SOLUTION: The printed wiring board is composed of a plurality of individual piece bodies having heat-dissipation characteristics and current characteristics, and an insulating resin provided around the individual piece bodies. The printed wiring board is composed so that both sides of the printed wiring board respectively have a planar face, and all the individual piece bodies and the insulating resin are flush with each other at least on one face. The manufacturing method has a step for arranging an adhesive sheet on the lower face of foil composed of a material having the heat-dissipation characteristics and the current characteristics, a step for adhering the individual piece bodies to the adhesive sheet while obtaining the individual piece bodies by blanking the foil with a die, a step for molding the insulating resin part around the individual piece bodies, and a step for planarizing the surface composed of the individual piece bodies and the insulating resin part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printed wiring board suitable for mounting electronic components that generate heat or for large currents and a method for manufacturing the same.

  In recent years, electronic components represented by LEDs (light emitting diodes) and the like have been used more than their convenience. However, since electronic components represented by LEDs and the like generate heat, in order for the electronic components to function properly in an electronic device, it is necessary to perform heat dissipation treatment on the generated heat part with an appropriate medium. The

  2. Description of the Related Art Conventionally, an electronic device generally attempts to solve a heat dissipation problem by configuring a heat sink around a heat-generating component by using a heat-dissipating fin, a fan and a Peltier element or a combination thereof. However, on the other hand, technical development has been made on a so-called heat-dissipation type printed wiring board in which the heat generating component mounted on the printed wiring board can be radiated by the printed wiring board itself.

  In the case where the heat generated by the heat-generating component is radiated by the printed wiring board, a thick conductor with good thermal conductivity is required. Thus, conventionally, the thick conductor has been formed by an etching type circuit forming method, but the following problems have arisen in forming a thick conductor circuit.

  Hereinafter, the problem in the circuit formation of this thick conductor will be described with reference to FIG. In FIG. 5A, first, a thick copper foil 41 with good thermal conductivity adhered to the insulating material 42 is prepared. Next, as shown in FIG. 5B, an etching resist for circuit formation is pasted as a mask 43, and exposure, development, conductor etching, and mask peeling steps are sequentially performed, and the circuit shown in FIG. A structure after completion of formation is obtained, but the structure after formation of the circuit is a problem.

  That is, since the structure after the circuit formation shown in FIG. 5C has a thick conductor, it is difficult to sufficiently etch the thick conductor when etching the circuit. There is a problem in that the skirt portion 45 causes a skirting problem and contacts with an adjacent circuit.

  Therefore, in view of the etching trouble of the thick conductor, as a structure for forming a heat radiation type printed wiring board without using an etching method for forming a heat radiation portion, for example, a structure as shown in FIG. 6 has already been reported. (See Patent Document 1).

  The power module shown in FIG. 6 includes a circuit board 53 in which a reinforcing material is impregnated with a thermosetting resin in advance, and an insulating resin mixture 54 containing an inorganic filler and an insulating resin in an opening formed in the circuit board 53. A filled one is prepared, and the insulating resin mixture 54 is used as a heat dissipation medium.

  That is, as shown in FIG. 6A, the lead frame 51 and the metal foil 52 are arranged on the upper surface of the circuit board 53 and the insulating resin mixture 54, and the metal foil 52 is arranged on the lower surface thereof. And the structure shown by FIG.6 (b) is obtained by carrying out lamination press. And finally, the power module which has the circuit wiring 55 shown by FIG.6 (c) is obtained by carrying out the circuit formation of the metal foil 52 of front and back.

  The power module shown in FIG. 6C includes a lead frame 51 suitable for a large current circuit formed in an insulating resin mixture 54 having a high heat dissipation property, and a fine wiring pattern 55 made of a metal foil. A structure in which an insulating resin mixture 54 as a high heat conductive layer with high heat dissipation is provided in a desired portion of the substrate 53. As a power module, a lead frame is used independently of a place where heat dissipation is necessary, while being independent. An island-like wiring pattern can be formed, and a fine wiring pattern can be formed in a place where heat radiation is not so necessary.

  However, the power module shown in FIG. 6 has the following problems.

  First, the insulating resin mixture 54 is used as a heat radiating member. However, in order to reliably radiate the heat generated from the parts or to move heat to the back surface, the heat radiating member is weak. Is that copper or a metal species having an equivalent heat transfer characteristic is required.

  Secondly, in order to reliably dissipate the heat generated from the components and to transfer heat to the back surface reliably, a structure that can mount a component that generates heat directly above the heat dissipation member is good. It is difficult to mount a component that generates heat immediately above the insulating resin mixture 54 as a member.

  Third, the heat radiation type power module shown in FIG. 6 uses the insulating resin mixture 54 as a heat radiation member, and the lead frame 51 as a large current circuit, and appropriately uses both in combination or alone to dissipate heat. However, it is necessary to pay special attention to the arrangement position, which hinders the design freedom of circuit wiring.

  Fourth, it is necessary to embed the lead frame 51 in the insulating resin mixture 54 by lamination, but this is difficult. That is, when embedding, the insulating resin mixture 54 requires an organic resin component having a relatively large amount of heat fluidity, while the insulating resin mixture 54 contains a large amount of inorganic filler in order to dissipate heat. Since it is necessary to contain, the material design of the insulating resin mixture 54 is difficult.

  Fifthly, the entire process shown in FIG. 6 is roughly divided into (i) a circuit board 53 in which a reinforcing material is impregnated with a thermosetting resin in advance, and an opening formed in the circuit board 53 with an inorganic filler and insulation. (Ii) a lead frame 51 is prepared by punching in advance, (iii) alignment and arrangement of the lead frame 51 before stacking, (iv) a stacking press, v) A large number of steps are required to form the circuit forming steps.

Japanese Patent No. 3214696

  Based on such background, the problem to be solved by the present invention is particularly suitable as a printed wiring board for mounting a heat-generating electronic component, excellent in heat dissipation function characteristics, excellent in large current characteristics, and short in the number of processes. It is providing the printed wiring board which can be manufactured by, and its manufacturing method.

  The inventor has made various studies in order to solve the above problems. As a result, it was found that if a printed wiring board provided with an insulating resin portion around a single piece obtained using a material having heat dissipation characteristics and current characteristics, extremely good results were obtained and the present invention was obtained. It came to be completed.

  That is, the present invention is a printed wiring board composed of a plurality of individual pieces having heat dissipation characteristics and current characteristics and an insulating resin portion provided in the periphery thereof, and the front and back of the printed wiring board are flat surfaces. In addition, the above-mentioned problem is solved by a printed wiring board in which all the individual pieces and the insulating resin portion are flush with each other on at least one surface.

  Further, in the present invention, the individual piece is composed of a first piece and a second piece having a smaller thickness, and the first piece on both the front and back sides of the printed wiring board. And the insulating resin portion are flush with each other, and the first individual piece, the second individual piece, and the insulating resin are provided on either of the front and back surfaces of the printed wiring board. The above-mentioned problems are solved by a printed wiring board characterized by being flush with the portion.

  Further, the present invention provides the above problem by a printed wiring board, wherein a conductor made of copper plating is formed on the same layer in which the individual pieces and the insulating resin portion are flush with each other. It has been solved.

  Moreover, this invention solves the said subject with the printed wiring board characterized by the said piece body consisting of the composite material of copper, a copper alloy, aluminum, an aluminum alloy, carbon, or carbon and a metal.

  Moreover, this invention solves the said subject with the printed wiring board characterized by the thickness of the said individual piece being 35 micrometers or more.

  Moreover, this invention solves the said subject with the printed wiring board characterized by the said insulating resin part being shape | molded with the thermosetting resin.

  Moreover, this invention solves the said subject with the printed wiring board characterized by the said insulating resin part being shape | molded with the thermoplastic resin.

  The present invention also includes a step of arranging an adhesive sheet on the lower surface of a foil made of a material having heat dissipation characteristics and current characteristics, and punching the foil with a mold to obtain a single piece, and at the same time, the individual sheet on the adhesive sheet. A step of adhering the pieces, a step of forming an insulating resin portion around the individual pieces bonded to the adhesive sheet, and a step of flattening the surface comprising the individual pieces and the insulating resin portion. The above-described problems are solved by a method for manufacturing a printed wiring board, comprising:

  In addition, the present invention further includes a step of forming a conductor made of copper plating on the flattened surface after the step of flattening the surface made of the individual piece and the insulating resin portion. The above-described problems are solved by a method for manufacturing a wiring board.

  Moreover, this invention solves the said subject by the manufacturing method of the printed wiring board characterized by shape | molding the said insulating resin part with a thermosetting resin.

  Moreover, this invention solves the said subject from the manufacturing method of the printed wiring board characterized by shape | molding the said insulating resin part with a thermoplastic resin.

  In addition, the present invention solves the above problems by a method for producing a printed wiring board, wherein the insulating resin portion is molded by an injection molding method, a compression molding method or a transfer molding method.

  Further, the present invention solves the above problems by a method for producing a printed wiring board, wherein the surface is flattened by buffing.

  Since the printed wiring board of the present invention has excellent heat dissipation function characteristics and excellent large current characteristics, it is particularly suitable for mounting electronic components that generate heat or as having heat dissipation effects of heat-generating components and heat transfer to the back surface. It can be suitably used as a printed wiring board for the purpose of large current. Further, when a conductor made of copper plating is formed, fine circuit wiring can be formed because the thickness is small. Furthermore, according to the method for producing a printed wiring board of the present invention, the printed wiring board of the present invention can be produced with a short number of steps, which is particularly advantageous in the case of industrial mass production.

(First embodiment)
With regard to the best mode for carrying out the present invention, a first embodiment will be described with reference to FIG.

  First, at least one foil 1 is prepared as a material for the purpose of heat dissipation and large current use. The foil 1 mainly has a conductor part for the purpose of heat radiation of the heat-generating component, heat transfer to the back surface part, or large current application. Therefore, the foil 1 is made of copper or copper as a material having high thermal conductivity and low electric resistance. It is preferable to use an alloy of aluminum or aluminum or an alloy of aluminum. In addition, in consideration of sufficient heat dissipation, and in addition to a problem caused by the above-mentioned skirting defect, in consideration of a technical background in which circuit formation is difficult, the foil 1 having a thickness of 35 μm or more is used. Is preferred. Thus, the material form depending on the thickness of the foil 1 includes not only the foil but also a sheet-like or plate-like form.

  On the other hand, as the material constituting the foil 1, carbon or a composite material of carbon and metal is also preferably used in addition to the copper or aluminum. This is because the foil 1 is mainly used for heat dissipation or heat transfer to the back surface, and the carbon or the composite material of carbon and metal has higher thermal conductivity than copper or aluminum.

  Next, for the purpose of processing the foil 1, the mold processing of the foil 1 is performed. Here, as a die processing method, it is performed by a die processing equipment for a lead frame that has been conventionally used. At that time, as shown in FIG. 1A, the punching degree in the mold 3 and the stroke and block 3b are used to adjust the punching degree. For example, in order to punch out the individual piece 4 having a good shape and attach the individual piece 4 to the adhesive sheet 2 with good adhesiveness, the lowest point of the punch 3a when the foil 1 is punched is set. is important. In particular, in order to affix the individual piece 4 to the adhesive sheet 2 with good adhesiveness, 0.05 to 0 further below the lowest point of the punch 3a necessary for punching the foil 1 by adjusting the stroke and block 3b. It is desirable to set the lowest point of the punch 3a within a range of .15 mm, apply a slight amount of pressure to the individual piece 4 with the punch 3a, and affix the individual piece 4 to the adhesive sheet 2 so as to be pressed. If the range is shallow, a positional deviation is likely to occur when the piece 4 is bonded to the adhesive sheet 2. Further, in the present invention, since the individual piece 4 punched by the mold processing of the foil 1 is used in the present invention, the adhesive sheet 2 is disposed on the lower surface of the foil 1 as shown in FIG. It is important to.

  That is, as shown in FIG. 1 (a), an adhesive sheet 2 is disposed on the lower surface of the foil 1, and then the foil 1 is punched out by a mold 3, as shown in FIG. 1 (b). The individual pieces 4 are individually bonded to the adhesive sheet 2 in a floating island state.

  Here, in the present invention, in forming the intended printed wiring board, the floating island state piece 4 cut by the mold 3 is meaningful.

  The conventional lead frame uses a portion in a frame state that is left after being punched out by the mold, whereas in the present invention, it is different in that the portion of the individual piece 4 punched out by the die is used. . In other words, the lead frame has a frame-like continuity because it uses the remaining part that is punched out, but since the individual pieces 4 in the present invention are independent of each other, heat is dissipated in the individual independent parts. Or the function as a heat transfer or a large-current use can be provided.

  Next, a mold is used around the floating island-shaped piece 4 shown in FIG. 1 (b) obtained by the above-described processing by injection molding, compression molding, transfer molding, or the like. As shown in (c), the insulating resin portion 5 is molded. In the present invention, the injection molding method is particularly preferably used because of the advantage that the generation of burrs is small.

  As a material of the insulating resin portion 5, it is preferable to use a thermosetting resin or a thermoplastic resin. Here, as thermosetting resin, phenol resin, epoxy resin, polyimide, bismaleimide triazine resin, melamine resin, cyanate resin, benzocyclobutene resin, unsaturated polyester, polybenzoxazole, polyphenylene ether, polyphenylene oxide, diallyl phthalate resin Are preferably used. As the thermoplastic resin, polyimide, polyester, liquid crystal polymer, fluororesin, polyether ether ketone, polynorbornene, polyethylene terephthalate, cycloolefin resin, polyphenylene sulfide, polyether sulfone, and acrylic resin are preferably used.

  Moreover, in order to give rigidity, a low linear expansion characteristic, and a heat dissipation characteristic to the structure obtained in the resin, a filler such as alumina or silica is further mixed to improve the function in terms of physical properties. More preferred above.

  When the insulating resin portion 5 is molded by the injection molding method, the molding die is designed so that the piece 4 is fixed by a part of the molding die. This is only a state in which the individual piece 4 is temporarily fixed on the adhesive sheet 2, and therefore the individual piece 4 is displaced from a predetermined position when the resin is thermally fluidized by the injection molding method. Because.

  Incidentally, when designing the molding die, it is also possible to form a three-dimensional structure by providing irregularities in the molding die. In other words, a printed wiring board having a desired structure can be obtained by appropriately designing the mold.

  As shown in FIG. 1C, the insulating resin portion 5 is formed on the floating island-shaped piece 4 by the injection molding method, so that the piece 4 and the insulating resin portion 5 are substantially flush with each other. A structure is obtained. Next, the printed sheet P1 shown in FIG. 1 (d) is obtained by peeling the adhesive sheet 2 from the structure shown in FIG. 1 (c).

  In the above manufacturing process, as the adhesive sheet 2, (i) Adhesive strength sufficient to bond the punched piece 4, (ii) Heat resistance capable of withstanding heat during molding resin processing in injection molding (Iii) Those having good peeling properties when obtaining the printed wiring board P1 are preferred.

  Examples of the adhesive sheet 2 having such characteristics include a heat-foamed adhesive sheet. This heat-foaming type adhesive sheet has an adhesive force for adhering the punched piece 4 under normal temperature environment, while it is foamed by heat during molding resin processing in injection molding. It has good release characteristics when obtaining P1. Therefore, it is suitably used as the adhesive sheet 2 having the above (i) adhesive strength, (ii) heat resistance, and (iii) good release characteristics.

  In addition, the adhesive sheet 2 is not limited to a single sheet having the heating and foaming characteristics, and the dimensional stability when obtaining the printed wiring board P1 is improved. It is more desirable to use it as a laminate in which a small number of sheets are further laminated.

  The printed wiring board P1 thus obtained has a structure in which the individual pieces 4 and the insulating resin portion 5 are flush with each other on the front and back surfaces. However, when a step occurs at the interface between the individual piece 4 and the insulating resin portion 5, the surface is appropriately flattened by buffing or the like.

  Here, the buffing is performed under relatively gentle polishing conditions because the piece 4 and the insulating resin portion 5 are bonded only on the side surface of the piece 4 in the printed wiring board P1. For example, for the purpose of cutting the residue portion due to the step of the printed wiring P1, it is preferable to perform buffing with the polishing current value set to 0.5 (A) or less.

  A feature of the printed wiring board P1 shown in FIG. 1A is that an electronic component that generates heat such as an LED is mounted on the individual piece 4 so that the individual piece 4 has a sufficient thickness. It is possible to dissipate heat or transfer heat to the back surface. The individual piece 4 is also preferably used as a printed wiring board for the purpose of large current.

  Further, as a feature of the printed wiring board P1 shown in FIG. 1A, since both the front and back surfaces have a structure in which the piece 4 and the insulating resin portion 5 are substantially flush with each other, the insulating resin Since the part 5 serves as a solder resist, it is possible to mount an electronic component without providing a special solder resist.

(Second embodiment)
Regarding the best mode for carrying out the present invention, a second embodiment will be described with reference to FIG.

  First, at least one or more sheets are prepared using different thickness foils, that is, relatively thin foil and relatively thick foil as materials. As in the first embodiment, these foils mainly have a conductor part for the purpose of heat dissipation of heat-generating parts, heat transfer to the back surface part, or large current applications, and thus have high thermal conductivity and resistance. As a material having a low value, it is preferable to use copper or a copper alloy.

  The thicknesses of the foils having different thicknesses are preferably appropriately selected from those having a thickness of 35 μm or more. For example, a 100 μm product is used as a thin foil, and a 750 μm product is used as a thick foil. For example, use a heat dissipation type printed wiring board suitable for the purpose. Moreover, as a material form by the thickness of the said foil, the thing of not only foil but a sheet-like or plate-like aspect is included.

  Next, for the purpose of processing the foil, the foil is molded. Here, as a mold processing method, as in the first embodiment, the adhesive sheet 2 is arranged on the lower surface of the foil, and as shown in FIG. The body 4 and the individual piece 7 are bonded to the adhesive sheet 2, but a punching process using a relatively thin foil mold is first performed, and only the punched individual piece 7 is attached to the adhesive sheet 2. Adhere.

  Next, after adjusting so that the position where the foil is applied is not displaced, a relatively thick foil mold is punched to bond the punched piece 4 to the adhesive sheet 2, and FIG. As shown in a), both the individual piece 7 (relatively thinner) and the individual piece 4 (relatively thicker) are bonded to the adhesive sheet 2.

  Next, using a molding die, for example, by an injection molding method, around the floating island-shaped piece 7 and piece 4 shown in FIG. The resin part 5 is molded. As the material of the insulating resin portion 5, a thermosetting resin or a thermoplastic resin is preferably used as in the first embodiment.

  By molding the insulating resin portion 5 on the floating island-like piece 7 and the piece 4 by the injection molding method, the piece 4, the piece 7, and the insulating resin portion on the adhesive sheet 2 side. The structure shown in FIG. 2B is obtained, in which the single-piece body 4 and the insulating resin portion 5 are flush with each other on the opposite side. Subsequently, the adhesive sheet 2 is peeled off from the structure shown in FIG. 2B, and the printed circuit board P2 shown in FIG. 2C is obtained by reversing the front and back.

  The printed wiring board P2 thus obtained has a single-sided structure 4 and an insulating resin portion 5 on both the front and back surfaces (upper and lower sides in the drawing), and the surface (upper surface in the drawing). ), The piece 4, the piece 7, and the insulating resin portion 5 are substantially flush with each other. However, in the case where a step occurs at the interface between the individual pieces 4 and 7 and the insulating resin portion 5 or the like, it is appropriately flattened by buffing or the like as in the first embodiment.

  As a feature of the printed wiring board P2 shown in FIG. 2 (c), in addition to the single body 4 mainly used for heat radiation of the heat-generating component, heat transfer to the back surface portion or large current application, a wiring circuit is mainly used. The individual piece 7 used as a role is that it is formed in a flush state on the surface layer. Thereby, for example, in the printed wiring board P2 shown in FIG. 2C, the heat generating component is mounted on the individual piece 4, and the electrical connection portion is connected to the individual piece 7 by bonding or the like from the heat generating component. It becomes possible.

(Third embodiment)
With respect to the best mode for carrying out the present invention, a third embodiment will be described with reference to FIG.

  In the structure shown in FIG. 3, the printed wiring board P <b> 1 obtained in the first embodiment is subjected to copper plating using chemical copper and electrolytic copper sequentially, and further subjected to heat treatment, and then the copper plating. By forming a circuit, a land portion 8 connected to the individual piece 4 and a conductor 9 mainly used for circuit wiring or the like are provided.

  Here, the circuit is formed by a subtractive method using a dry film etching resist or an electrodeposition resist, which is a conventional method for forming a printed wiring board circuit. For example, as a circuit forming method, after roughening the surface of the copper plating, a dry film etching resist is laminated on the copper surface, and then exposed to ultraviolet light and developed with an aqueous sodium carbonate solution in an exposure machine. After etching using the ferric liquid, the dry film etching resist is peeled off to form the land 8 and the conductor 9 to obtain the printed wiring board shown in FIG.

  The printed wiring board shown in FIG. 3 has various features by providing the land portion 8 on the individual body 4 mainly used for heat dissipation of the heat-generating component, heat transfer to the back surface portion, or large current application. Since a mounting connection location suitable for the structure of various electronic components having a size can be provided, the use as a heat radiation type printed wiring board is expanded.

  In addition, the conductor 9 made only of copper plating can be used as fine circuit wiring because of its thin thickness, and when used in a pad structure, the electrical connection location can be formed by bonding or the like from a heat generating component. It becomes possible to connect to the conductor 9.

(Fourth embodiment)
Regarding the best mode for carrying out the present invention, a fourth embodiment will be described with reference to FIG.

  The structure shown in FIG. 4 is obtained by performing copper plating on the printed wiring board P2 obtained in the second embodiment by using chemical copper and electrolytic copper sequentially, and then forming the copper plating circuit. A land portion 8 connected to the individual piece 4 and a conductor 9 mainly used for circuit wiring or the like are provided.

  As a feature of the printed wiring board shown in FIG. 4, there is an individual piece 7 in the vicinity of the individual piece 4 mainly used for heat dissipation of heat-generating components, heat transfer to the back surface portion, or large current application. Therefore, it becomes possible to connect the electrical connection location to the individual piece 7 by bonding or the like.

  Further, since the conductor 9 made of only copper plating is thin as in the third embodiment, it can be used as fine circuit wiring, and when it is used in a pad structure, it generates heat. It becomes possible to connect the electrical connection portion to the conductor 9 by bonding or the like.

  As described above in detail, the method for producing a printed wiring board of the present invention comprises a short number of steps such as (i) stamping of foil, (ii) molding resin processing, and (iii) formation of circuit wiring on the surface layer portion. For this reason, the printed wiring board of the present invention can be manufactured particularly advantageously in the case of industrial mass production.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic cross-sectional process explanatory drawing which shows 1st embodiment of this invention. The schematic cross-sectional process explanatory drawing which shows 2nd embodiment of this invention. The schematic cross-section explanatory drawing which shows 3rd embodiment of this invention. FIG. 6 is a schematic cross-sectional explanatory view showing a fourth embodiment of the present invention. Schematic cross-sectional process explanatory drawing which shows the manufacturing method of the conventional printed wiring board. Schematic cross-sectional process explanatory drawing which shows the manufacturing method of the other conventional printed wiring board.

Explanation of symbols

1: Foil 2: Adhesive sheet 3: Mold 4: Individual piece 5: Insulating resin portion 7: Individual piece 8: Land portion 9: Conductor 41: Copper foil 42: Insulating material 43: Mask 44: Circuit 45: Hem 51: lead frame 52: metal foil 53: circuit board 54: insulating resin mixture 55: wiring pattern P1: printed wiring board P2: printed wiring board

Claims (13)

  A printed wiring board composed of a plurality of individual pieces having heat dissipation characteristics and current characteristics and an insulating resin portion provided around the plurality of individual pieces, and at least one of the front and back surfaces of the printed wiring board is a flat surface The printed wiring board according to claim 1, wherein all of the individual pieces and the insulating resin portion are flush with each other.   The individual piece is composed of a first individual piece and a second individual piece having a smaller thickness, and on both the front and back sides of the printed wiring board, the first individual piece and the insulating resin. The first piece, the second piece, and the insulating resin portion are flush with each other on either the front or back side of the printed wiring board. The printed wiring board according to claim 1, wherein the printed wiring board is formed.   The printed wiring board according to claim 1, wherein a conductor made of copper plating is formed in the same layer in which the individual pieces and the insulating resin portion are flush with each other.   The printed wiring board according to any one of claims 1 to 3, wherein the individual piece is made of copper, a copper alloy, aluminum, an aluminum alloy, carbon, or a composite material of carbon and metal.   The printed wiring board according to any one of claims 1 to 4, wherein the individual piece has a thickness of 35 µm or more.   The printed wiring board according to claim 1, wherein the insulating resin portion is formed of a thermosetting resin.   The printed wiring board according to claim 1, wherein the insulating resin portion is formed of a thermoplastic resin.   A step of arranging an adhesive sheet on the lower surface of a foil made of a material having heat dissipation characteristics and current characteristics, and a step of punching the foil with a mold to obtain an individual piece and simultaneously adhering the individual piece to the adhesive sheet And a step of forming an insulating resin portion around the individual piece bonded to the adhesive sheet, and a step of flattening a surface comprising the individual piece and the insulating resin portion. Manufacturing method of printed wiring board.   9. The printed wiring according to claim 8, further comprising a step of forming a conductor made of copper plating on the flattened surface after the step of flattening the surface made of the individual pieces and the insulating resin portion. A manufacturing method of a board.   The method for manufacturing a printed wiring board according to claim 8 or 9, wherein the insulating resin portion is formed of a thermosetting resin.   The method for manufacturing a printed wiring board according to claim 8 or 9, wherein the insulating resin portion is formed of a thermoplastic resin.   The method for manufacturing a printed wiring board according to any one of claims 8 to 11, wherein the insulating resin portion is molded by an injection molding method, a compression molding method, or a transfer molding method.   The method for producing a printed wiring board according to any one of claims 8 to 12, wherein the surface is flattened by buffing.

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