JP2009021274A - Manufacturing method of printed wiring board, and member used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve quality etc., by charging resin in a core hole of a metal core without leaving any air bubble when a metal core printed wiring board is manufactured. <P>SOLUTION: Before a resin-impregnated sheet 21 is put over the metal core 11 having the core hole 13, a conductive metal coating portion 22 made of copper foil 22a is provided on one side 21b of the resin-impregnated sheet 21 on the opposite side from a surface facing the metal core 11 and an end surface 21c connecting with the one side 21b and at an outer peripheral edge part 21d of a base material opposition surface connecting with the lower end surface, thereby preventing resin from projecting during heating and pressing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a printed wiring board, and more particularly to a method for manufacturing a printed wiring board capable of preventing air bubbles from being present inside.

  The metal core printed wiring board as an example of the printed wiring board has been manufactured as follows. First, as shown in FIG. 13A, prepregs (resin impregnated sheets) 102 are stacked on both surfaces of the metal core 101 that has been subjected to the hole 101 a drilling process, and metal foils 103 are stacked on the prepregs 102, respectively. Next, as shown in FIG. 13 (b), the metal core 101, the prepreg 102, and the metal foil 103 are laminated and integrated by sandwiching and pressing between them with a pressing plate 104 such as a thick stainless steel plate having a smooth surface. The obtained metal-clad laminate 105 is obtained. Subsequently, the metal-clad laminate 105 is subjected to predetermined processing such as peripheral trimming, drilling a hole (through hole) at a position corresponding to the hole 101a of the metal core 101, plating, pattern formation, resist processing, and the like. Go and manufacture.

  By the way, the above heat and pressure aims at forming an insulating layer made of resin on the metal core 101, but at the time of this processing, the resin of the prepreg 102 is sufficiently placed in the hole 101a formed in advance on the metal core 101. It is necessary to fill. If the air bubble 106 remains without being sufficiently filled (see FIGS. 13C and 13D), the insulation resistance with the metal core 101 deteriorates, the withstand voltage decreases, and the temperature changes. A problem such as delamination will occur.

  For this reason, as disclosed in the following Patent Document 1, heating and pressurization has been performed in a vacuum.

  However, depending on the size, arrangement, number, etc. of the holes in the metal core, the bubbles 105 may remain as shown in FIG.

For this reason, as disclosed in the following Patent Document 2, a prepreg having a minimum melt viscosity of 600 to 1000 Pa · s is obtained under the condition that the ratio of the height to the inner diameter of the core hole (hole), that is, the aspect ratio is 12 or less. It has been proposed that the molding pressure be increased to 10 kg / cm ² or more and heated simultaneously.

  However, even in this case, when the density of the holes in the metal core is high, the resin cannot be sufficiently filled, and bubbles 106 are formed in the insulating coating made of the resin.

  The heating and pressurization is performed by sandwiching between the pressing plates 104 as described above. However, when the heating and pressurization is performed, deformation occurs so that the resin protrudes from the end of the prepreg 102 as shown in FIG. In the center side t1 and the peripheral part t2, the thickness was uneven.

  In addition, the edge portion that has been deformed so as to be warped and increased in thickness becomes a hindrance in the drilling or plating process of the next process, and therefore it is necessary to trim the edge part before passing to the next process. When the pressing plate 104 is made larger than the metal foil 103, an increase in the surrounding thickness can be reduced. However, in that case, there is a problem that the protruding resin adheres to the pressing plate.

Furthermore, since the resin is semi-cured in the prepreg 102, the end face of the prepreg is fragile and the resin powder 107 (cut powder) as shown in FIG. Etc.) (powder falling, powder scattering) and not only harming the working environment, but also adhered as foreign matter in the subsequent process, causing defects such as dents and causing a decrease in yield.
Japanese Unexamined Patent Publication No. 64-89592 JP-A-10-322020

  Accordingly, the main object of the present invention is to minimize the influence of conditions such as the arrangement of holes in a base material such as a metal core, and to more reliably eliminate the remaining of bubbles.

  For that purpose, a method for producing a printed wiring board is obtained by stacking and integrating a resin-impregnated sheet on a perforated substrate and then heating and pressurizing them to fill the resin in the resin-impregnated sheet into the hole. In the previous stage of stacking the resin-impregnated sheet on the base material, the surface of the resin-impregnated sheet opposite to the surface facing the base material, the end surface continuous from this surface, and the base material facing from this end surface This is a method for manufacturing a printed wiring board in which a metal film portion is provided around the surface.

The metal coating portion is provided by means such as metal foil coating or plating. The metal coating portion provided on the resin-impregnated sheet before the heating and pressurization functions to confine the resin of the resin-impregnated sheet that is deformed by the pressure during the heating and pressurization. As a result, the internal pressure is increased and the filling of the resin into the holes of the base material is promoted.
The said base material is comprised, for example with a metal core, a double-sided printed wiring board, etc.

  Another means is a resin-impregnated sheet in which a metal coating portion is provided on one surface, an end surface continuous from this surface, and a peripheral portion of the opposite surface continuous from this end surface.

  The metal coating part is provided by means such as metal foil coating or metal plating. When receiving the forming process by heating and pressurization, the metal coating part acts to confine the resin of the resin-impregnated sheet that is deformed by receiving pressure, thereby increasing the internal pressure.

  Another means is a metal-clad laminate in which a perforated base material, a resin-impregnated sheet for forming an insulating layer, and a metal coating layer are laminated and integrated, and in the resin-impregnated sheet before lamination and integration A metal coating portion is formed on the surface opposite to the surface facing the substrate, and the metal coating portion integral with the metal coating portion is also formed on the end surface of the resin-impregnated sheet and the peripheral portion of the substrate facing surface. It is the formed metal-clad laminate.

The metal coating part is provided by means such as metal foil coating or metal plating. The metal coating portion provided on the resin-impregnated sheet acts to confine the resin of the resin-impregnated sheet that is deformed by the pressure during heating and pressurization for stacking and integration. For this reason, an internal pressure increases and the filling of the resin in the hole of a base material is accelerated | stimulated.
The said base material is comprised, for example with a metal core, a double-sided printed wiring board, etc.

  Another means is a metal core printed wiring board manufactured by the above-described printed wiring board manufacturing method, wherein the base material is a metal core, or a multilayer printed wiring board where the base material is a double-sided printed wiring board.

  As described above, according to the present invention, the metal coating portion provided on the resin-impregnated sheet confines the resin inside and heats the resin into the hole in the base material when heating and pressurizing for lamination integration. Since the inflow is promoted, the resin can be sufficiently filled. As a result, residual bubbles can be eliminated.

  Moreover, since the metal coating part presses the end surface of the resin-impregnated sheet at the time of heating and pressing, escape due to deformation of the compressed resin can be suppressed and the thickness can be made uniform.

  Furthermore, since the metal film part is formed in the end surface of the resin-impregnated sheet, the end part of the resin-impregnated sheet having a semi-cured resin can be protected. As a result, powder falling and powder scattering can be prevented, generation of defective products can be eliminated, and yield can be improved.

  In addition, since the end surface of the resin-impregnated sheet is covered with a metal coating portion and the deformation is suppressed, the end surface portion can be transferred to the next process as it is without cutting off, and work efficiency can be improved. .

An embodiment for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is an explanatory view showing a manufacturing process of a metal core printed wiring board as an example of a printed wiring board. First, an outline of the process will be described according to FIGS. 1A to 1J, and then the main part will be described.

  As a material of the metal core 11, a rectangular metal plate 12 made of copper or aluminum is used (a).

  A metal core 11 is obtained by mechanically opening a core hole (hole) 13 in the metal plate 12 and performing a degreasing process such as washing with water, followed by a roughening process to roughen the surface (b).

  Next, resin impregnated sheets 21 with metal coating portions are arranged on both surfaces of the metal core 11. The metal coating portion 22 is conductive and is provided on the surface of the resin impregnated sheet 21 opposite to the metal core 11 and the outer peripheral edge portion (c).

  In this state, heat and pressure are applied in a vacuum, and the resin in which the resin-impregnated sheet 21 is melted is filled in the core hole 13 of the metal core 11. When the resin is solidified, it becomes a single metal-clad laminate 31 in which insulating layers 21a are formed on both surfaces of the metal core 11 (d).

  Thereafter, a through hole 31a having a smaller diameter than the core hole 13 of the metal core 11 and penetrating in the thickness direction is opened in the resin-filled portion of the metal-clad laminate 31 (e).

  Subsequently, a copper plating layer 32 is formed on the inner surface of the through hole 31a. The plating consists of electroless plating and electrolytic plating. A circuit pattern layer 31b is formed by the layer composed of the copper plating layer 32 and the metal coating portion 22 (f).

  A predetermined portion on the circuit pattern layer 31b is covered with a mask 33 (g), and the portion of the circuit pattern layer 31b not covered with the mask 33 is removed (h).

  Thereafter, the mask 33 is removed (i), and a solder resist 34 for insulating a part of the circuit is formed at a predetermined portion of the surface (j).

  Finally, external processing is performed, and a coating such as a preflux or a solder leveler is applied as appropriate to complete a metal core printed wiring board.

  Next, the resin-impregnated sheet 21 (FIG. 2A) used in the step (c) and the metal-clad laminate 31 (FIG. 2B) obtained by laminating the resin-impregnated sheet 21 on the metal core 11 will be described.

  The resin-impregnated sheet 21 is prepared by impregnating a glass base fabric with a thermosetting resin and dried by heating. After the cutting, the resin-impregnated sheet 21 is used for constituting the metal coating portion 22. Cover with copper foil 22a (FIG. 3).

  That is, as shown in FIG. 3, the copper foil 22a formed in a rectangular shape that is slightly larger than the resin-impregnated sheet 21 is used (FIG. 3 (a)), as shown in FIGS. 3 (b) and 3 (c). As described above, the coating is provided so as to cover the one surface 21b of the resin-impregnated sheet 21, the four end surfaces 21c continuous from the one surface 21b, and the outer peripheral edge portion 21d of the opposite surface continuous from the four end surfaces 21c. Do. The covering range in the outer peripheral edge 21d on the opposite surface is kept within the range to be cut in the final outer shape processing. Since the end portion of the resin-impregnated sheet 21 is covered with the metal coating portion 22, powder does not fall from the end surface as in the conventional case, and it is possible to avoid the occurrence of defects and improve the yield.

  In this way, the resin-impregnated sheet 21 coated with the copper foil 22 a is overlapped with the surface on which the resin-impregnated sheet 21 is exposed facing the metal core 11 as shown in FIG.

  The size of the resin impregnated sheet 21 is set to be slightly larger than that of the metal core 11, and is set to a size such that a part of the inner peripheral side of the surface facing the metal core 11 in the metal coating portion 22 is superposed on the metal core.

  Subsequently, as shown in FIG. 4 (a), when heated and pressurized in a vacuum sandwiched between stainless plates 41 larger than the resin-impregnated sheet 21, as shown in FIG. 4 (b), the resin-impregnated sheet The resin 21 melts and enters the core hole 13 of the metal core 11. That is, the core hole 13 is filled with resin.

  At this time, the end surfaces 21c of the resin impregnated sheet 21 are covered with the metal coating portion 22 as shown in FIG. 4B, and the metal coating portions 22 are continuous on both sides with the end surface 21c interposed therebetween. Therefore, even when the resin-impregnated sheet 21 is compressed, the resin does not deform so as to protrude from the end face. For this reason, the filling of the resin into the core hole 13 of the metal core 11 can be performed at a stretch while the pressure of the internal resin is high, and bubbles can be prevented from remaining.

  Moreover, since there is no deformation | transformation which resin protrudes as mentioned above, the thickness of the metal-clad laminated board 31 becomes uniform.

  As described above, the stainless steel plate 41 when heating and pressurizing is larger than the resin-impregnated sheet 21 (see FIG. 4A), and this also suppresses a change in the thickness of the edge portion. In addition, since the outer peripheral portion around the end surface of the resin-impregnated sheet 21 is covered with the metal coating portion 22 so as not to be exposed, it is possible to prevent the resin from protruding. As a result, the resin does not adhere to the stainless steel plate 41, and it is possible to save troubles such as resin removal.

  Further, since the change in the thickness of the edge portion is suppressed, the state moves to the next step as shown in FIG. 5 without cutting out (trimming) the edge portion as in the prior art. After finishing the predetermined processing, external processing is performed. That is, the conventional step of trimming the edge portion and the step of polishing the end face can be omitted, and the number of steps can be reduced and the working efficiency can be increased. In FIG. 5B, 32 is a copper plating layer, and in particular, 32a is through-hole plating.

  FIG. 6A is a perspective view of a resin-impregnated sheet according to another example, and FIG. 6B is a cross-sectional view of the main part. As shown in FIG. It can also be formed by plating 22b.

  A 0.2 mm thick resin impregnated sheet 21 coated with 0.07 mm thick copper foil 22a on both sides of a 0.4 mm thick metal core 11 as shown in FIGS. Hereinafter, it is referred to as “product of this example”), and the presence or absence of bubbles and the thickness thereof were inspected.

  As a comparative example, a 0.2 mm thick resin-impregnated sheet and a 0.07 mm thick copper foil are sequentially stacked in parallel on both sides of a 0.4 mm thick metal core and heated and pressed under the same conditions. A tension laminate (hereinafter referred to as “comparative product”) was produced, and the presence and thickness of bubbles were similarly inspected.

  In order to verify the effect of the arrangement of the core holes 13 and the like, the concept of unit and average aperture ratio was adopted, and the test core 14 as shown in FIG.

Here, the aperture ratio is calculated as follows.
As shown in FIG. 8, when the core hole A and the core hole B are assumed, the aperture ratio = pitch P / diameter D is calculated. This is the opening ratio between the core hole A and the core hole B. The core holes A and B are assumed to have various shapes such as a circular shape, an elliptical shape, and an oval shape, and it is assumed that such core holes are arranged in various directions. As shown in Fig. 5, the larger diameter of the straight diameters Da and Db on the straight line connecting the centroids Oa and Ob (centers in the case of a circle) of the core hole A and the core hole B is adopted as the diameter D. The distance between the centroids Oa and Ob is generalized by adopting the distance P as the pitch P.

  The unit is a group in which the core holes are formed adjacent to each other, and more specifically, when the opening ratio of the adjacent core hole B with respect to a certain core hole A is within 2.5, the core hole B is also It is determined that the core is included in the same unit as the core hole A.

  In addition, with respect to such a unit, the average aperture ratio refers to any one of the core holes A close to the center of the unit, and the core holes for all the core holes (not limited to the adjacent core holes) existing around the core hole A. The aperture ratio is calculated individually, and only the core holes having an aperture ratio of 2.5 or less are selected, and the average value is referred to as the average aperture ratio of the unit.

  If the opening ratios of all the surrounding core holes are calculated based on a certain core hole and all become larger than 2.5, the core hole is independent and falls under the above unit. Not to be calculated and excluded from the calculation of the average aperture ratio.

  In addition, when a core hole that is not actually used is generated, the core hole is also removed from the core hole that is the target of the unit.

  The test core 14 shown in FIG. 7 has a size of 340 mm × 510 mm, and in this test core 14, the round hole has four types of inner diameters of 2.6 mm, 3.6 mm, 4.6 mm, and 6.8 mm. Each round hole is arranged as a single unit by arranging 5 × 5 round holes of the same size, and the long hole has a width of 2.5 mm and a length of 6. There are 6 sizes of 9mm, 9.1mm, 11.3mm, 13.5mm, 15.7mm, 17.9mm, and each slot has 1 slot with the same size. Arranged as one unit.

  For the first slot 13a having an inner diameter of 2.6 mm, the first unit has a pitch of 3.8 mm in the “row” direction (x direction) and a pitch of 5.8 mm in the “column” direction (y direction). 51, a second unit 52 having a pitch of 3.8 mm in the “row” direction and a pitch of 4.8 mm in the “column” direction, a pitch of 3.8 mm in the “row” direction, and 3 in the “column” direction. A third unit 53 having a pitch of .8 mm is arranged adjacent to each other in the column direction. In this case, the average aperture ratios in the column direction of the first, second and third units 51, 52 and 53 for the first round hole 13a are 2.45, 2.10 and 1.76, respectively.

  Regarding the second round hole 13b having an inner diameter of 3.6 mm, the first unit 54 having a pitch of 4.8 mm in the “row” direction and a pitch of 6.8 mm in the “column” direction, A second unit 55 having a pitch of 4.8 mm and a pitch of 5.8 mm in the “column” direction, and a third unit 55 having a pitch of 4.8 mm in the “row” direction and a pitch of 4.8 mm in the “column” direction. Are arranged adjacent to each other in the column direction. In this case, the average aperture ratios in the column direction of the first, second and third units 54, 55 and 56 for the second round hole 13b are 2.10, 1.85 and 1.61, respectively.

  For the third round hole 13c having an inner diameter of 4.6 mm, a first unit 57 having a pitch of 5.8 mm in the “row” direction and a pitch of 7.8 mm in the “column” direction; A second unit 58 having a pitch of 5.8 mm and a pitch of 6.8 mm in the “column” direction, and a third unit 58 having a pitch of 5.8 mm in the “row” direction and a pitch of 5.8 mm in the “column” direction. Are arranged adjacent to each other in the column direction. In this case, the average aperture ratios in the column direction of the first, second, and third units 17, 18, and 19 for the third round hole 13c are 1.90, 1.71, and 1.52, respectively.

  For the fourth round hole 13d having an inner diameter of 6.8 mm, the first unit 60 having a pitch of 7.8 mm in the “row” direction and a pitch of 9.8 mm in the “column” direction; A second unit 61 having a pitch of 7.8 mm and a pitch of 8.8 mm in the “column” direction, and a third unit 61 having a pitch of 7.8 mm in the “row” direction and a pitch of 7.8 mm in the “column” direction. Are arranged adjacent to each other in the column direction. In this case, the average aperture ratios in the column direction of the first, second, and third units 60, 61, and 62 for the fourth round hole 13c are 1.64, 1.51, and 1.38, respectively.

  The first to sixth elongated holes 4e to 4j are respectively a first unit 63 having a pitch of 3.5 mm in the “row” direction and a second unit 64 having a pitch of 5.28 mm. , A third unit 65 having a pitch of 6.2 mm and a fourth unit 66 having a pitch of 7.2 mm are disposed adjacent to each other. The average aperture ratio of the first unit 63 of each of the long holes 13e to 13j is 1.4, the average aperture ratio of the second unit 64 is 2.08, the average aperture ratio of the third unit 65 is 2.48, The average aperture ratio of the four units 66 is 2.88.

  MCL-BE-67G (HHFQ) manufactured by Hitachi Chemical Co., Ltd. having a resin content of 47%, 49%, 51% and 53% was used for the prepreg as a resin-impregnated sheet laminated on the test core 14.

  In the experiment, 10 sets of resin-impregnated sheets with copper foil stacked on both sides of the test core were stacked and placed in the first stage of a 5-stage vacuum hot press in an environment with a degree of vacuum of 10 to 20 torr or less. Heating and pressurization were performed while adjusting the temperature and pressure as shown in FIG. An apparatus manufactured by Meiki Seisakusho Co., Ltd. was used as a 5-stage vacuum hot press.

As shown in FIG. 9, the resin is melted by changing the heating temperature from room temperature T ₀ to primary temperature T ₁ of 130 ° C. at a predetermined rate of temperature increase, and simultaneously pressurized as primary pressure P ₁ at 10 kgf / cm ² for a predetermined time. . Subsequently, the heating temperature is maintained at 120 to 130 ° C., which is the primary temperature T ₁ , for 20 to 30 minutes, and the pressure is increased to a secondary pressure P _{2 of} , for example, 30 kgf / cm ² . As a result, the resin flows into the core hole. Further, while maintaining the secondary pressure P ₂ of 30 kgf / cm ₂ , the heating temperature is increased to a secondary temperature T ₂ , for example, 170 ° C. or higher at a temperature rising rate of 2.0 to 3.5 ° C./min, and then the heating is performed. The resin is cured by maintaining the temperature at 170 ° C. and the applied pressure of 30 kgf / cm ² for 40 minutes or more, and then cooled until the temperature reaches room temperature T ₀ .

And experiment was conducted about two cases, when the rate of temperature increase to the primary temperature T ₁ was 2.0 ° C./min and when it was 3.5 ° C./min.

  As a result, the results as shown in FIG. 10 were obtained for the presence or absence of bubbles.

  That is, as a whole, there is a tendency that bubbles are formed at a portion where the value of the opening ratio is low, and bubbles increase as the resin content increases. However, in the comparative example product, bubbles are inevitably generated at 1.32 where the value of the opening ratio is the lowest. It will remain.

  On the other hand, in the case of the product of the present invention, it is understood that bubbles do not remain even when the aperture ratio value is 1.32 which is the lowest, and the generation level of bubbles can be suppressed as a whole.

  The thickness was measured at nine points as shown in FIG. 11 after cutting out unnecessary portions of the metal-clad laminate. Nine points are the intersection (four corners) of four lines 71 parallel to each side drawn at a position of 10 mm inward from the periphery of the metal-clad laminate, and in the long side direction and short side direction through the center. The two lines 72, 72 extending along the line are a point where the above line intersects (near the middle part of each side) and a center 73.

  The results are as shown in FIG. The thickness value is made to correspond to nine positions.

  As shown in this table, in the case of the product of the present invention, the minimum value was 0.93 mm and the maximum value was 0.97 mm. The average was 0.95 mm, which was close to the nominal value of 0.94.

  On the other hand, in the case of the comparative product, the minimum value was 0.92 mm, the maximum value was 0.99, and the average value was 0.96.

  Looking at the standard deviation (STD), the product of the present invention was reduced by half compared to the comparative product, and there was little variation in thickness, and a flatter metal-clad laminate could be manufactured. I understand.

  In the above description, the case where the base material is the metal core 11 has been described. However, the base material may be a double-sided printed wiring board, and in this case, a multilayer printed wiring board having a total of four layers of conductors is obtained.

In correspondence between the configuration of the present invention and the configuration of the above-described one form,
The hole of the present invention corresponds to the core hole 13 described above,
Similarly,
The surface opposite to the surface facing the metal core and one surface correspond to the one surface 21b,
The end surface continuous from the opposite surface corresponds to the end surface 21c,
The peripheral portion of the substrate facing surface corresponds to the outer peripheral edge portion 21d of the opposite surface,
The present invention is not limited to the above configuration, and other forms can be adopted.

Explanatory drawing which shows the outline of the manufacturing process of a metal core board | substrate. The perspective view of a resin impregnation sheet | seat and a metal-clad laminated board. The perspective view which shows the structure of a resin impregnation sheet | seat and a metal-clad laminated board. Sectional drawing of an action state. Sectional drawing of an action state. Explanatory drawing of the resin impregnation sheet | seat which concerns on another example. The top view of a test core. Explanatory drawing for demonstrating aperture ratio. Explanatory drawing which shows heating-pressing conditions. A table showing the presence or absence of bubbles. Explanatory drawing which shows the measurement point of thickness. Table showing thickness data. Sectional drawing which shows the problem of a prior art. Sectional drawing which shows the problem of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Metal core 13 ... Core hole 21 ... Resin impregnation sheet | seat 21b ... One side 21c ... End surface 21d ... Outer peripheral edge part 22 ... Metal coating part 22a ... Copper foil 22b ... Copper plating 31 ... Metal-clad laminate

Claims (11)

A method for producing a printed wiring board in which a resin-impregnated sheet is stacked on a perforated base material, and these are heated and pressed to be laminated and integrated in a state where the resin of the resin-impregnated sheet is filled in the hole,
Before the resin-impregnated sheet is overlaid on the substrate, the surface of the resin-impregnated sheet opposite to the surface facing the substrate, the end surface continuous from this surface, and the peripheral portion of the substrate facing surface continuous from this end surface And a method of manufacturing a printed wiring board in which a metal coating is provided. The method for producing a printed wiring board according to claim 1, wherein the metal coating portion is provided by coating with a metal foil. The method for manufacturing a printed wiring board according to claim 1, wherein the metal coating portion is provided by plating. The said base material is a metal core, The said printed wiring board is a metal core printed wiring board, The manufacturing method of the printed wiring board as described in any one of Claims 1-3. The method for producing a printed wiring board according to any one of claims 1 to 3, wherein the substrate is a double-sided printed wiring board, and the printed wiring board is a multilayer printed wiring board. A resin-impregnated sheet in which a metal coating portion is provided on one surface, an end surface continuous from this surface, and a peripheral portion of the opposite surface continuous from this end surface. A metal-clad laminate in which a perforated base material, a resin-impregnated sheet for forming an insulating layer, and a metal coating layer are laminated and integrated,
On the surface opposite to the surface facing the base material in the resin-impregnated sheet before being laminated and integrated, a metal film portion is formed,
A metal-clad laminate in which a metal coating part integral with the metal coating part is also formed on the end face of the resin-impregnated sheet and the peripheral part of the substrate facing surface. The metal-clad laminate according to claim 7, wherein the base material is a metal core, and the metal-clad laminate is a metal-core laminate. The metal-clad laminate according to claim 7, wherein the substrate is a double-sided printed circuit board and the metal-clad laminate is a multilayer laminate. A metal core printed wiring board manufactured by the method for manufacturing a printed wiring board according to claim 1, 2, or 3, wherein the substrate is a metal core. A multilayer printed wiring board produced by the method for producing a printed wiring board according to claim 1, 2, or 3, wherein the substrate is a double-sided printed wiring board.

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