JP2014236035A - Manufacturing method of circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a circuit board with high interlayer and pattern coincidence and superior in via connection reliability.SOLUTION: A laminated prepreg 3 is processed by using a laser beam 21 which passes through adjacent to the center of an fθ lens 23 to form a through hole 4a with little distortion in hole diameter. By using the hole with little distortion as a mark for positioning, a circuit board with high lamination coincidence and pattern coincidence can be obtained.

Description

  The present invention relates to a method of manufacturing a circuit board formed by connecting a plurality of layers of circuit patterns.

  In recent years, with the downsizing and increasing the density of electronic devices, there has been a strong demand for highly functional circuit boards not only for industrial use but also for consumer use. In particular, miniaturization of connected parts and higher functionality make it more important to form finer circuit patterns, and the improvement of the via position accuracy and shape, which are the key points of connection, are important to ensure their connection reliability. Yes.

  A conventional circuit board manufacturing method will be described below.

  FIG. 7 is a process sectional view of a conventional method for manufacturing a double-sided circuit board.

  First, reference numeral 51 shown in FIG. 7A denotes a prepreg which is a substrate material in which a glass cloth is impregnated with a thermosetting epoxy resin, and the size in length, width and thickness is 500 mm × 500 mm × 0.1 mm. .

  Reference numeral 52 denotes a plastic film having a thickness of about 19 μm which becomes a mask film when filled with a conductive paste, and has a thermosetting resin layer on one side and a release layer coated with silicon or the like on the opposite side. For example, polyethylene terephthalate (hereinafter referred to as PET sheet) is used.

  The process shown in FIG. 7B is a laminating process in which the prepreg 51 is sandwiched between the PET sheets 52 and the PET sheets 52 are attached to both surfaces of the prepreg 51.

  On the release layer side of the PET sheet 52, the prepreg 51 is heated and pressurized from any one side by a laminating roll (not shown) having at least two upper and lower sets as one set, and sequentially directed toward the opposite side of the prepreg. A sheet 52 is pasted on both sides of the prepreg 51 to form a laminated prepreg 53.

  Next, as shown in FIG.7 (c), the through-hole 54 is formed in the predetermined location of the laminated prepreg 53 with a laser processing apparatus. At this time, positioning through-holes for alignment and multilayering of the conductive through-holes and the exposure film, which are products, are also opened at the same time.

  In addition, the entire area of the prepreg is processed by a combination of a processing table (not shown), an fθ lens 73, and a galvanometer mirror 72.

  Next, as shown in FIG. 7 (d), a laminated prepreg 53 having a through hole 54 is installed using a printing machine (not shown), and a squeegee 55 serves as a print mask for the PET sheet 52. A conductive hole 57 is formed by filling the through hole 54 with the conductive paste 56 from the front side.

  Next, as shown in FIG. 7E, the prepreg 58 filled with the conductive paste is formed by peeling the PET sheet 52 from both sides of the laminated prepreg 53.

  By the process of peeling off the PET sheet 52, the conductive paste filled in the holes formed in the PET sheet 52 remains in the form of convex ridges corresponding to the thickness of the PET sheet 52. In the heating and pressurizing step described later, a compression effect is brought about, which contributes to the stability of electrical connection of the conduction holes.

  Next, as shown in FIG. 7 (f), a metal foil 59 such as copper foil is stacked on both sides of the prepreg 58 filled with the conductive paste, and the metal foil 59 is filled with the conductive paste by heating and pressing with a hot press. Bonding with the finished prepreg 58 forms a double-sided copper-clad laminate 60 shown in FIG.

  The metal foils 59 on both sides are electrically connected by a conductive paste in a conduction hole 57 provided at a predetermined position.

  Then, as shown in FIG. 7H, the double-sided metal foil 59 is selectively etched to form a circuit pattern 61, whereby a double-sided circuit board 62 is obtained.

  Next, a conventional method for manufacturing a multilayer circuit board will be described with reference to FIG.

  FIG. 8 is a process cross-sectional view showing a conventional method for manufacturing a multilayer circuit board, and shows a four-layer board as an example.

  First, as shown in FIG. 8 (a), the two-sided circuit board 62 manufactured according to FIGS. 7 (a) to 7 (h) and the through hole 54 manufactured in FIGS. 7 (a) to 7 (e) are electrically connected. An electrically conductive paste filled prepreg 58a for filling an upper layer and a conductive paste filled prepreg 58b for a lower layer are prepared.

  Next, in the step shown in FIG. 8B, a metal foil 59 is placed on a lamination stage (not shown), and a conductive paste filled prepreg 58b for lower lamination is placed on the reference hole position by image recognition or the like. Are stacked after recognition positioning is performed, and the circuit boards 62 on both sides are similarly recognized and positioned, and then laminated, and the conductive paste filled prepreg 58a for upper stacking is similarly recognized and positioned on the stack. This is an alignment laminating step in which the metal foil 59 is further laminated thereon.

  Next, as shown in FIG. 8 (c), the prepregs 58a and 58b filled with the conductive paste sandwiched between the metal foils 59 and the circuit boards 62 on both sides are heated and pressed by hot press to form a four-layer copper-clad laminate 63. Get.

  Through the above-described steps, the outermost metal foil 59 is electrically connected by the circular circuit pattern 61 for connecting the inner-side circuit boards 62 via the conductive paste in the conduction hole.

  Next, as shown in FIG. 8D, a four-layer circuit board 65 is obtained by selectively etching the metal foils 59 on both sides to form a circuit pattern 64.

  Here, a four-layer multilayer substrate has been described. However, for a multilayer substrate having four or more layers, for example, a six-layer substrate, the four-layer circuit substrate obtained by the manufacturing method is used in place of the double-sided circuit substrate. The method {FIGS. 8A to 8D} may be repeated.

  As prior art document materials related to the invention of this application, for example, Patent Documents 1 and 2 are known.

Japanese Patent Laid-Open No. 9-246718 JP 2001-256568 A

  In the case of the above circuit board manufacturing method, when the through-hole 54 is processed with a laser at an arbitrary position of the laminated prepreg 53 in the step of FIG. 7C, the vertical and horizontal lengths of 500 mm are provided on a processing table equipped with XY moving means. A laminated prepreg 53 with a size of × 500 mm is fixed, and laser light irradiated from a laser oscillator is carried to a desired processing point via a plurality of mirrors, galvanometer mirrors, and fθ lenses to perform hole processing.

  In the process of FIG. 7C, the processing table can be processed by scanning the laser beam within a certain range (for example, 50 mm × 50 mm) with the processing table fixed by using a galvanometer mirror and an fθ lens. The entire surface of the laminated prepreg 53 having a size of 500 mm × 500 mm can be processed by moving to XY at a constant pitch.

  Therefore, the processing position accuracy of the through hole 54 is determined by a combination of the scanning accuracy of the galvano mirror, the distortion due to the aberration of the fθ lens, and the position accuracy of the processing table.

  Next, FIG. 9 is a conceptual diagram when drilling holes in the circuit board of the present invention.

  As shown in FIG. 9A, a perfect circular through hole is easily opened especially when the laser beam 21 passes near the center of the fθ lens 23. However, as shown in FIG. The through-holes processed by passing near the outer periphery of the steel have a tendency to be distorted.

  For example, when the positioning through hole is opened with the laser beam 71 that has passed through a position close to the outer periphery of the fθ lens 73 near the limit of the scanning range, there is a high possibility that the position is shifted or the hole shape is distorted. There is a fear.

  As a conventional measure, a method for reducing the scanning range has been proposed. In the above laser processing apparatus, there is a tendency that the laser beam can be drilled with higher accuracy near the center of the fθ lens, that is, near the center of the scanning range. For this reason, only the vicinity of the center of the scanning range is used for drilling, thereby improving the accuracy of the through hole. However, since only a small number of holes can be processed, problems remain in productivity.

  In addition, if the scanning range is widened, the scanning range by the galvanometer mirror will be widened. As a result, the operating distance of the galvanometer mirror 72 will increase, and the galvanometer mirror stop position will vary easily due to inertia. There is a high possibility that the positional accuracy will be lowered.

  Further, if it is attempted to cope with the problem by increasing the number of fθ lenses, etc., this leads to a large cost increase, which is not efficient.

  Therefore, when positioning the pattern film in the pattern process and the upper and lower layers, the optical system looks at the center of gravity of the through hole and positions it with the pattern film and the upper and lower prepregs. If there is, there is a high possibility that the positioning accuracy is deteriorated, the mating deviation occurs, and an electrical failure such as a short circuit occurs.

  Conventional circuit board manufacturing methods have been manufactured on the premise that there is such a positional shift, and thus there has been a problem that the yield is lowered due to a decrease in conformity.

  In order to achieve the above object, in the method of manufacturing a circuit board according to the present invention, when forming a through hole, a hole for positioning is formed by forming a through hole for positioning at a coordinate passing near the center of the fθ lens. By forming a small hole with high hole position accuracy, the position accuracy of the positioning through-hole is increased, and the position accuracy of the pattern film and the position of the upper and lower prepregs are improved.

  The present invention includes a step of attaching a plastic sheet having releasability to the front and back of a prepreg, and irradiating a laser beam to an arbitrary position of the prepreg attached with the plastic sheet, thereby forming through holes for conduction and positioning. Forming and filling the through-hole with conductive paste, peeling the plastic sheet from the prepreg, sandwiching the plastic sheet-filled conductive paste filled prepreg with metal foil, And forming a pattern by etching the metal foil, and processing data for forming the positioning through hole is processed by using data that the laser beam passes near the center of the fθ lens. The circuit board manufacturing method is characterized by the fact that it is easy to change the design data and reduce distortion. Obtained through hole for deciding, and has a function of obtaining a high positioning accuracy circuit board.

  Further, as a means for forming the positioning through-hole, the circuit board manufacturing method is characterized in that the processing table is moved to a location that passes near the central portion of the fθ lens and processed. By moving the processing stage, positioning through-holes with less distortion can be obtained, and a circuit board having a high alignment accuracy can be obtained.

  Further, the circuit board is formed by combining a plurality of positioning through holes, and is processed by moving a processing table within a scanning range including all of the positioning through holes. This is a manufacturing method, and by collecting a group of positioning through-holes within the same scanning range, high-precision positioning through-holes with no NC position accuracy variation of the machining table can be obtained, and a circuit board with high positional accuracy It has the effect | action which obtains.

  Next, a step of preparing a plurality of conductive paste-filled prepregs from which the plastic sheet has been peeled off, a metal foil and the conductive paste-filled prepreg, or a metal foil, the conductive paste-filled prepreg, and an inner layer substrate, Or a method of manufacturing a circuit board, comprising a step of laminating double-sided or multilayer circuit boards through the prepreg filled with the conductive paste and heating and pressurizing, and a through hole for positioning with high accuracy with less distortion By performing positioning between layers, the circuit board having a high interlayer matching property can be obtained.

  In addition, the metal foil and the conductive paste filled prepreg, or the metal foil, the conductive paste filled prepreg and the inner layer substrate, or the double-sided or multilayer circuit board are laminated and heated through the conductive paste filled prepreg. A method of manufacturing a circuit board comprising a step of forming a circuit pattern on the metal foil after the pressurizing step, and a prepreg and pattern filled with a conductive paste having a through-hole for positioning with little distortion The film has an action that can be adjusted with high accuracy.

  Further, the inner layer substrate obtained by using the circuit board manufacturing method of the present invention and the circuit board on both sides are formed by sandwiching a prepreg filled with a conductive paste with a metal foil, and heat-pressing the metal foil with a hot press. Is a circuit board manufacturing method characterized in that a pattern is formed by etching, and circuit patterns or layers between the front and back surfaces are electrically connected by the conductive paste. It has the effect | action which improves the conduction | electrical_connection reliability of a board | substrate body, and insulation reliability.

  According to the present invention, an electrically conductive paste-filled prepreg having positioning through-holes with low distortion and high positional accuracy can be obtained by the method for manufacturing a circuit board having the above-described configuration. Interlayer positioning in the lamination with the substrate and the alignment with the copper clad laminate with high positional accuracy and the pattern film can be performed with high accuracy by forming with the prepreg filled with conductive paste. Therefore, a circuit board with stable electrical connection and high connection reliability between layers can be provided with high productivity.

Sectional drawing which shows the manufacturing method of the circuit board in Embodiment 1 of this invention Process sectional drawing which shows the manufacturing method of the multilayer circuit board in Embodiment 1 of this invention Schematic in which a prepreg is installed on a processing table having XY moving means in Embodiment 1 of the present invention. Schematic of installing a prepreg on a processing table having XY moving means in Embodiment 2 of the present invention. Schematic showing an example of a processing pattern of a positioning hole used in a conventional method of manufacturing a circuit board used in the present invention Schematic which shows the manufacturing method of the circuit board in Embodiment 3 of this invention. Process sectional view showing a conventional method of manufacturing a circuit board Cross-sectional process diagram showing a conventional multilayer circuit board manufacturing method Schematic which shows the manufacturing method of the circuit board in embodiment of this invention

(Embodiment 1)
The circuit board manufacturing method of the present invention will be described below.

  In the present embodiment, a double-sided circuit board will be described.

  FIG. 1 is a process sectional view showing a circuit board manufacturing method according to an embodiment of the present invention.

  First, the prepreg 1 in FIG. 1A is a substrate material in which a glass cloth is impregnated with a thermosetting epoxy resin, and the size of the length, width, and thickness is 500 mm × 500 mm × 0.1 mm.

  A plastic sheet (hereinafter referred to as a PET sheet) 2 is a plastic film having a thickness of about 19 μm serving as a mask film.

  The PET sheet 2 has a hole diameter control layer (not shown) having a thickness of about 1.2 μm made of a thermosetting resin having no melting point on the surface layer of the plastic film, and a surface in contact with the prepreg 1 on the opposite side. For example, it has a structure having a release layer coated with silicon or the like.

  In addition, as a base material of PET sheet 2, for example, polyethylene terephthalate is used, but there is no problem even if PEN or PPS is used.

  Next, as shown in FIG. 1 (b), the prepreg 1 is sandwiched between the prepregs 1 by sandwiching the prepreg 1 with the PET sheet 2 and applying heat and pressure by a method such as laminating. Form.

  Next, as shown in FIG.1 (c), the through-hole 4 is formed in the predetermined location of the laminated prepreg 3 using the laser processing method. 21 is a laser beam, 22 is a galvanometer mirror for scanning the laser beam 21 on the fθ lens, and 23 is an fθ lens for condensing the laser beam scanned on the substrate onto the laminated prepreg 3.

  In the laser processing step in FIG. 1 (c), FIG. 3 shows a case where a through hole used for positioning of a pattern film or positioning at the time of lamination is processed. Hereinafter, it is shown as a positioning through hole 4a.

  FIG. 3 shows a case where a laminated prepreg 3 is installed on a processing table 24 having XY moving means. For convenience of explanation, the processing areas of the galvano mirror 22 and the fθ lens 23 are divided by lines.

  The processing table 24 is stepped at a pitch separated by a line, and the entire laminated prepreg 3 is processed. Since the laser light 21 naturally hits a position near the outer periphery of the fθ lens 23 in the vicinity of the processing area, the distortion of the through hole tends to increase. Therefore, by designing the positioning through-hole 4a to be near the center of the processing area, the laser beam 21 is passed through the vicinity of the center of the fθ lens 23 and irradiated to the laminated prepreg 3, thereby causing distortion. Design considerations will be made so that drilling with a low roundness and high positional accuracy can be obtained.

  As a result of confirmation by the present inventor, when the scanning range of the galvano mirror 22 is 50 mm × 50 mm, if the laser beam 21 is allowed to pass within 20 mm from the center of the fθ lens 23, the roundness is 0.9 or more. A through hole having a high roundness is obtained, and the through hole 4a for positioning is drilled within the range.

  Of course, since there is a difference between facilities, it is desirable to investigate the distortion of the hole before setting and to set a range including the range. In general, the positioning through-hole 4a is recognized as one pattern by combining a plurality of positioning through-holes 4a as shown in FIG. 5, but the positioning through-hole 4a is arranged as follows. Since the PCD is within a range of 2 mm × 2 mm such as 1.8 mm, there is no problem even in a narrower range.

  Further, it is generally known that by drilling the laser beam 21 through the vicinity of the center of the fθ lens 23, the swing angle of the galvano mirror 22 is reduced, the rotational inertia is suppressed, and the positional accuracy is improved. It will also be advantageous from the aspect of.

  Next, as shown in FIG. 1 (d), using a printing machine (not shown), the conductive paste 6 is filled into the through hole 4 from the top of the PET sheet 2 with the squeegee 5 to form the conduction hole 7.

  In this process, the front side PET sheet 2 plays the role of a printing mask, and the hole diameter of the through hole 4 drilled in the PET sheet 2 contributes to the connection reliability between the layers of the circuit board and the conformity in the multilayer stacking process. To do.

  Next, as shown in FIG. 1 (e), when the PET sheet 2 is peeled from both surfaces of the laminated prepreg 3 in which the through holes 4 are filled with the conductive paste 6, the conductive paste-filled prepreg 8 is formed.

  Next, as shown in FIG. 1 (f), both sides of the prepreg 8 filled with the conductive paste are overlapped with a metal foil 9 such as copper foil, and heated and pressed by hot press, whereby both sides shown in FIG. 1 (g). The copper clad laminate 10 is formed. The metal foils 9 on both sides are electrically connected via a conductive paste in a conduction hole 7 provided at a predetermined position.

  And as shown in FIG.1 (h), the metal foil 9 of both surfaces is selectively etched, the circuit pattern 11 is formed, and the circuit board 12 of both surfaces is obtained, but the through-hole 4a for positioning is as follows. Since a hole with extremely small distortion processed by passing near the center of the fθ lens is used, alignment with the film can be performed with high accuracy.

  In addition, if the positioning through hole is not a single hole but multiple points such as five holes as shown in FIG.

  Next, the manufacturing method of the multilayer circuit board of this invention is demonstrated using FIG.

  FIG. 2 is a process cross-sectional view illustrating a method of manufacturing a multilayer circuit board according to the present invention, and illustrates a four-layer board as an example.

  First, as shown in FIG. 2 (a), the double-sided circuit board 12 manufactured according to FIGS. 1 (a) to 1 (h) and the through holes 4, 4a manufactured in FIGS. 1 (a) to (e). The conductive paste 6 is filled and the conductive layer 6 is filled with the conductive layer 6 filled with the conductive paste 6 and the conductive layer 6 filled with the conductive layer 6 is prepared.

  Next, in the step shown in FIG. 2B, the metal foil 9 is placed on a lamination stage (not shown), and the conductive paste-filled prepreg 8b is recognized and positioned by image recognition or the like. Lamination is performed later, and the circuit boards 12 on both sides are similarly recognized and positioned thereon, and then laminated, and the prepreg 8a filled with the conductive paste is recognized and positioned in the same manner, and further laminated on the metal foil. 9 is an alignment laminating process for laminating 9.

  At this time, since the hole used for positioning uses the through hole 4a in which the laser beam 21 is passed through the vicinity of the center of the fθ lens 23, alignment is performed using a hole processed with high accuracy with less influence of aberration and less distortion. Do.

  Next, as shown in FIG. 2 (c), the prepregs 8a and 8b filled with the conductive paste sandwiched between the metal foils 9 and the circuit boards 12 on both sides are heated and pressed by hot press to form a four-layer copper-clad laminate 13 Get.

  Through the above-described steps, the outermost metal foil 9 is electrically connected by the circular circuit pattern 11 for connecting the circuit boards 12 on both sides for the inner layer through the conductive paste in the conduction hole.

  Next, as shown in FIG. 2D, a four-layer circuit board 15 is obtained by selectively etching the metal foils 9 on both sides to form a circuit pattern 14. At this time, the hole used for positioning is a hole with extremely small distortion that is processed by passing the laser beam 21 through the vicinity of the center of the fθ lens 23, so that the alignment with the film can be performed with high accuracy. If the positioning through hole 4a is not a single hole but multiple points such as five holes as shown in FIG.

  Here, a four-layer multilayer substrate has been described. However, for a multilayer substrate having four or more layers, for example, a six-layer substrate, a four-layer circuit board obtained by the manufacturing method is used instead of a double-sided circuit board, and a multilayer substrate manufacturing method is used. What is necessary is just to repeat {FIG.2 (a)-(d)}.

  As a result, in addition to providing a circuit board with high connection reliability between layers by realizing the manufacturing method of a circuit board with high matching accuracy in the first embodiment, productivity in the manufacturing process of the circuit board is improved. Improvements can be made.

(Embodiment 2)
In the second embodiment, although the manufacturing process is the same as that of the first embodiment, in the laser processing step shown in FIG. 1C, a normal laminated prepreg 3 is placed on the processing table 24 and the through hole 4 is formed. As in the past, the area divided by the scanning range of the galvanometer mirror 22 is processed by step feed. However, if the design through hole 4a cannot be formed at the center of the fθ lens 23, any area as shown in FIG. The processing table 24 is operated at the position so that the positioning through hole 4 a is formed at the center of the fθ lens 23.

  Thereby, the design freedom of the formation position of the through hole for positioning increases. Further, by operating the processing table 24, the swing angle of the galvano mirror 22 is reduced, and the rotational inertia is suppressed and the positional accuracy is increased.

  In addition, the circuit board of the present invention can be obtained through the same processes as those of the first embodiment in the manufacturing process of the double-sided circuit board and the manufacturing process of the multilayer board.

  Further, when obtaining a multilayer circuit board, a plurality of prepregs filled with conductive paste are produced by the method of Embodiment 2, positioned between the plurality of circuit boards, sandwiched between metal foils, and heated and pressed. Can be obtained.

(Embodiment 3)
In the third embodiment, a case where a positioning through hole is machined in the through hole laser machining process shown in FIG. 1C will be described with reference to FIGS.

  FIG. 5 shows the processing data of the pattern of the positioning through-hole 4a used at the time of general positioning. In general, a pattern is formed by a combination of 5 or 9 holes, and the pattern at a plurality of through-holes is recognized by image recognition or the like. Recognize with high accuracy.

  When the processing pattern of the positioning through-hole 4a formed by a plurality of holes of two or more holes shown in FIG. 6 (a) extends over two or more galvano scan areas (shown by a dotted line for convenience) As shown in FIG. 6B, the processing pattern of two or more positioning through-holes 4a extends over two or more scanning areas, and the outermost part of the processing pattern from the vertical (Y) horizontal (X) distance of the scanning area. When the distance (Y1) is shorter, the machining table 24 is moved and machined in the same manner as in the second embodiment so as to be within the same scanning range, as shown by the alternate long and short dash lines.

  Alternatively, since the NC position accuracy of the machining table 24 does not vary by machining with machining data designed so that the plurality of through holes 4a for positioning are within the same galvano scan area range, the machining accuracy is high. Efficient drilling can be performed.

  Subsequent manufacturing steps are similar to those of the first embodiment, whereby the circuit board of the present invention can be obtained.

  As described above, a highly accurate positioning hole can be processed by using the circuit board manufacturing method of the present invention.

  For this reason, it becomes easy to align the prepreg having a conduction hole formed with high positional accuracy and the circuit pattern of the inner layer substrate, and even in a multilayer circuit board having a delicate pattern, the conduction hole and the inner layer substrate It is possible to improve the matching accuracy with the circuit pattern and provide a circuit board with high connection reliability between the layers with high productivity.

  Moreover, it is easy to adopt the technique of the present invention and to spread the technique, and it can be said that the industrial applicability of the present invention is great.

1, 51 Prepreg 2, 52 PET sheet 3, 53 Laminated prepreg 4, 4a, 54 Through hole 5, 55 Squeegee 6, 56 Conductive paste 7, 57 Conductive hole 8, 58 Prepreg filled with conductive paste 9, 59 Metal Foil 10, 60 Copper-clad laminate 11, 14, 61, 64 Circuit pattern 12, 62 Circuit board 13, 63 4-layer copper-clad laminate 15, 65 4-layer circuit board 21 71 Laser light 22, 72 Galvano mirror 23, 73 fθ lens 24 processing table

Claims (5)

Attaching a plastic sheet having releasability to the front and back of the prepreg;
By irradiating a laser beam to any position of the prepreg with a plastic sheet attached,
Form through holes for conduction and positioning,
Filling the through hole with a conductive paste;
A step of peeling the plastic sheet from the prepreg, a step of sandwiching the conductive paste-filled prepreg from which the plastic sheet has been peeled between metal foils, heating and pressing with a hot press, and a step of forming a pattern by etching the metal foil ,
A method of manufacturing a circuit board, wherein the processing data for forming the positioning through-hole is processed using data in which a laser beam passes near the center of the fθ lens. 2. The method of manufacturing a circuit board according to claim 1, wherein as the means for forming the positioning through-hole, the processing table is moved to a location that passes near the center of the f [theta] lens. 3. The method according to claim 2, wherein a plurality of the positioning through holes are combined to form a group, and the processing table is moved to a scanning range including all of the positioning through holes. The manufacturing method of the circuit board of description. Attaching a plastic sheet having releasability to the front and back of the prepreg;
By irradiating a laser beam to any position of the prepreg with a plastic sheet attached,
Form through holes for conduction and positioning,
Filling the through hole with a conductive paste;
Peeling the plastic sheet from the prepreg;
Preparing a plurality of prepregs filled with conductive paste from which the plastic sheet has been peeled, and
A step of laminating a metal foil and the conductive paste filled prepreg or a metal foil, the conductive paste filled prepreg and the inner layer substrate or the conductive paste filled prepreg, and heating and pressing both sides or a multilayer circuit board. A method for manufacturing a circuit board, comprising: A step of laminating a metal foil and the conductive paste-filled prepreg or a metal foil, the conductive paste-filled prepreg and the inner layer substrate or the conductive paste-filled prepreg and heating and pressing the double-sided or multilayer circuit board. rear,
The method for manufacturing a circuit board according to claim 4, further comprising a step of forming a circuit pattern on the metal foil.