JP2018157059A - Printed wiring board and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed wiring board in which even if a metal piece is placed, as heat release means, in a metal piece housing hole, the metal piece does not project from the opening end of the metal piece housing hole, and does not become a little too short, nor crack is generated.SOLUTION: A printed wiring board for transmitting heat generated from an electronic component to a radiator, placed on the side opposite to the electronic component mounting surface, by means of a metal piece placed directly under the electronic component consists at least of an insulation substrate, a metal piece housing hole penetrating the insulation substrate, and a header method formation metal piece placed fixedly in the metal piece housing hole via an adhesive. The electronic component connection side exposed surface of the metal piece is located below the position of the electronic component mounting surface side opening of the metal piece housing hole, and the radiator connection side exposed surface of the metal piece is located at a position recessed from the position of the radiator arrangement surface side opening end of the metal piece housing hole.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a printed wiring board for transferring heat generated from an electronic component to a heat dissipating member disposed on the opposite side of the electronic component mounting side by a metal piece disposed immediately below the electronic component, and It relates to a manufacturing method.

  As a means to efficiently dissipate heat generated from electronic components (for example, surface mounted components such as “FET” and “MOSFET”) that generate a large amount of heat, it penetrates directly under the electronic components mounted on the printed wiring board. A method of providing a plurality of thermal vias made of plated through holes and radiating heat to the outside via a heat radiating body (heat radiating pattern or heat sink) disposed on the back side of the printed wiring board has been generally used. It was.

However, due to advances in functionality and performance of equipment, the amount of heat generated from electronic components has increased to a level that is incomparable to conventional products. It is no longer possible (that is, it is impossible to dissipate heat enough to operate electronic components normally).
Therefore, in recent years, means for embedding a metal piece (for example, “copper piece”) having a large heat capacity in place of the thermal via has been reported (for example, see Patent Document 1).

An example of the printed wiring board configured to embed the “metal piece” will be described with reference to the schematic cross-sectional view of the printed circuit board Pc shown in FIG.
Note that the terms “printed wiring board” and “printed circuit board” appear in the text (including the text explaining the configuration of the present invention), but for convenience of explanation, before mounting and arranging the electronic components and the radiator. "Printed wiring board" is used, and the printed circuit board after mounting and arranging these is used separately.
In addition, in the description when the metal piece is accommodated in the metal piece accommodation hole, the terms “electronic component mounting surface side opening end” and “heat radiator arrangement surface side opening end” appear, but here the “opening end” Does not mean only the opening end portion of the “metal piece receiving hole” provided in the “insulating substrate”, but is provided so as to surround the “metal piece receiving hole opening end”, for example, FIG. When the “outer layer wiring patterns 3a and 3b” and the “solder resist 7” shown in FIG. 6 are present between the “electronic parts and radiator” and the opening end of the “metal piece receiving hole”, It means an opening end formed by “outer layer wiring patterns 3a, 3b” and “solder resist 7”. In FIG. 5, reference numeral 10 denotes an adhesive, 8A denotes the position of the electronic component mounting surface side opening end, and 8B denotes the position of the heat dissipating element arrangement surface side opening end.

  In FIG. 6, the printed circuit board Pc includes at least an insulating substrate 1, an electronic component 11 mounted on one surface of the insulating substrate 1, and a radiator (heat sink) disposed on the other surface of the insulating substrate 1. 14), the metal piece housing hole 8 penetrating the insulating substrate 1, the electronic piece 11 disposed in the metal piece housing hole 8 and the electronic component 11 via the solder 13 on the electronic component connection side exposed surface 99A side. The metal piece 99 connected to the radiator 14 via the thermally conductive adhesive (thermally conductive and insulating grease or sheet) 15 on the radiator connecting side exposed surface 99B side, The electronic component mounting side surface A of the insulating substrate 1 includes a solder resist 7 formed so as to surround the metal piece accommodation hole 8. Note that reference numeral 12 shown in the drawing is a terminal drawn out from the electronic component 11, and is connected to a mounting pad 3c provided on the printed wiring board Pw via solder.

  As the metal piece 99 disposed in the metal piece housing hole 8, a metal piece 99 provided with a recess 99a on the electronic component connection side exposed surface 99A side for suppressing the outflow of solder during the soldering process is used. In addition, the surface opposite to the concave portion 99a, that is, the surface on the convex portion 99b side, is disposed so as to be flush with the heat dissipating surface B of the insulating substrate 1 (the surface on which the heat dissipating body 14 is disposed). ing.

By the way, the most important point in manufacturing a printed wiring board used for this type of printed circuit board is the protrusion of the metal piece arranged in the metal piece accommodation hole in the Z-axis direction.
For example, in the printed wiring board Pw shown in FIG. 6, when the electronic component connection side exposed surface 99A protrudes beyond the solder resist 7 formed so as to surround the metal piece housing hole 8, the electronic component 11 may occur, and when the radiator connecting side exposed surface 99B protrudes from the lower surface of the edge substrate 1 (the radiator disposing side surface B), the metal piece 99 and the metallic This is because there is a concern that the insulation reliability between the metal piece 99 and the heat radiating body 14 cannot be secured because the distance from the heat radiating body 14 becomes narrow and the insulating heat conductive adhesive 15 becomes thin. is there.

  However, the printed wiring board Pw shown in FIG. 6 has the following problems in practice.

That is, as the metal piece 99 disposed in the metal piece receiving hole 8, a metal plate punched by a die press is used (the metal piece 99 has a concave portion 99a and a convex portion 99b. ) When the wear of the press die progresses, the metal piece 99 with high dimensional accuracy cannot be manufactured, and the opening end of the metal piece receiving hole 8 (the position 8A of the electronic component mounting surface side opening end or the heat dissipating surface side) There was a risk that the metal piece 99 would protrude from the open end position 8B) or that an incomplete piece would be placed.
Thus, when the metal piece 99 protrudes from the opening end of the metal piece accommodation hole 8, the problem as described above occurs, and on the other hand, when an incomplete thing is arranged, the electronic component 11 and Actually, the void 13 is generated in the solder 13 that thermally connects the metal piece 99 or the distance between the metal piece 99 and the heat radiating body 14 is increased, so that a desired heat dissipation effect cannot be obtained.

  In addition, when a metal plate is punched with a die press, each time the plate thickness of the insulating substrate 1 is changed, it is necessary to prepare a metal plate that matches the thickness. .

In addition, in the printed wiring board Pw disclosed in Patent Document 1, the “press-fit method” is adopted as a method for arranging the metal pieces 99.
That is, in the “press-fit method”, the metal piece 99 having a diameter smaller than the diameter of the metal piece receiving hole 8 and longer than the dimension of the metal piece containing hole 8 in the Z-axis direction is plastically deformed (deformed by pressure). Thus, since the metal piece 99 is fixed in the metal piece accommodation hole 8 (that is, fixed by a force that pushes the inner wall of the metal piece accommodation hole 8 in the XY direction), a crack is generated in the insulating substrate 1. Because there is concern.

Furthermore, in the printed wiring board shown in Patent Document 1, “the surface on the convex portion 99b side of the metal piece 99 and the lower surface of the insulating substrate 1 (the heat dissipating element side surface B) are arranged on the same plane”. Is also a concern.
The reason is that when a large warp has occurred in the insulating substrate 1 (printed wiring board Pw) (see “warp portion” shown in FIG. 7), the exposed surface 99B on the radiator side of the metal piece 99 is a metal piece. Since there is a possibility that the housing hole 8 protrudes from the position 8B of the opening side of the heat dissipating member arrangement surface side, there is a risk that the insulation reliability with the heat dissipating member 14 as described above cannot be secured. It is.

Japanese Patent No. 5858630

  The present invention has been made in view of the above-described conventional problems and actual circumstances, and even when a metal piece is disposed in the metal piece accommodation hole as a heat dissipation means, the metal piece is an open end of the metal piece accommodation hole. In addition, the printed wiring board that does not protrude or become smaller than the above, and has no cracks in the insulating substrate due to the insertion of the metal piece, and such a printed wiring having excellent insulation reliability and heat dissipation. It is an object to provide a manufacturing method for obtaining a plate.

  As a result of repeating various studies to solve the above problems, the present inventor used a metal piece manufactured by a header method with high dimensional accuracy, and if the metal piece was fixed with an adhesive, an extremely good result was obtained. The present invention was completed by finding out that it can be obtained.

  That is, the present invention provides a printed wiring board that transfers heat generated from an electronic component to a heat dissipating member disposed on a surface opposite to the electronic component mounting side surface by a metal piece disposed immediately below the electronic component. The metal piece includes at least an insulating substrate, a metal piece housing hole penetrating the insulating substrate, and a header method-forming metal piece fixedly disposed in the metal piece housing hole via an adhesive. The electronic component connection side exposed surface is at a position equal to or less than the position of the electronic component mounting surface side opening end of the metal piece housing hole, and the radiator connecting side exposed surface of the metal piece is a heat radiator of the metal piece housing hole. The above-mentioned problems are solved by a printed wiring board characterized by being in a position recessed from the position of the arrangement surface side opening end.

  Further, the present invention provides a printed wiring board for transferring heat generated from an electronic component to a heat dissipating member disposed on a surface opposite to the electronic component mounting side by a metal piece disposed immediately below the electronic component. In the manufacturing method, at least the step of forming the metal piece housing hole in the insulating substrate, and when the metal piece is placed in the metal piece housing hole, the exposed surface of the metal piece on the electronic component connection side is an electron in the metal piece housing hole. Length that is below the position of the component mounting surface side opening end, and that the exposed surface of the metal piece on the radiator connecting side is recessed relative to the position of the opening on the radiator side of the metal piece receiving hole When the metal piece is disposed in the metal piece receiving hole, the exposed surface of the metal piece on the heat sink connecting side is opened on the heat sink arranging surface side of the metal piece containing hole. Metal having a protrusion with a height that can be placed at a position recessed from the end A step of arranging the jig in a state in which the positions of the metal piece receiving holes and the protrusions are aligned on the heat dissipating member arrangement side surface of the insulating substrate, and the metal pieces via the protrusions of the jig. Inserting the metal piece into the metal piece receiving hole, and supplying the adhesive to the gap between the metal piece containing hole and the metal piece, and fixing the metal piece into the metal piece containing hole. The above-described problems are solved by a method for manufacturing a printed wiring board.

According to the present invention, since the metal piece processed by the header method with high processing accuracy (that is, high dimensional accuracy) is used as the metal piece arranged in the metal piece accommodation hole, the metal piece is accommodated in the metal piece accommodation hole. Even when the pieces are arranged, there is no problem that the metal piece protrudes from the metal piece receiving hole or is not short.
In addition, as a method of fixing the metal piece, a method of pouring adhesive into the gap formed between the inner wall of the metal piece receiving hole and the metal piece is adopted, so that cracks that have been a problem during the press-fitting method occur. I don't have to.

The schematic sectional drawing of the printed circuit board using this invention printed wiring board. (A)-(c) is a schematic sectional process drawing which shows the manufacture example of this invention printed wiring board. (D)-(f) is a schematic sectional process drawing following FIG. The schematic plan view which shows the fixed state of the metal piece in this invention printed wiring board. The schematic sectional drawing which shows the position of the opening end of the metal piece accommodation hole in this invention printed wiring board. 1 is a schematic cross-sectional view of a conventional printed circuit board. The principal part schematic sectional drawing which shows the example in which the curvature part generate | occur | produced in the insulated substrate in the conventional printed wiring board.

  Hereinafter, an embodiment of the printed wiring board of the present invention will be described with reference to FIG. For convenience of explanation, the description will be made assuming that the stage before the metal piece is accommodated in the metal piece accommodation hole is the “insulating substrate”, and the one after the accommodation is the “printed wiring board”.

  In FIG. 1, PW is a printed wiring board, and its insulating substrate 1 includes three core insulating layers 100, inner layer wiring patterns 2 formed on the boundary surface and front and back surfaces of the three core insulating layers 100, and A core substrate 1a composed of a buried hole 4 for connecting the inner layer wiring pattern 2 formed on each surface of the three-layer core insulating layer 100 in the vertical direction, and one layer is laminated on the front and back surfaces of the core substrate 1a. The interlayer insulating layer 101 and the build-up layer 1b composed of the outer layer wiring patterns 3a and 3b and the mounting pads 3c formed on the outer layer side of the interlayer insulating layer 101, and the core substrate 1a and the front and back of the core substrate 1a The inner layer wiring pattern 2 and the outer layer wiring patterns 3a and 3b formed on the core substrate 1a and the buildup layer 1b. Through-plated through-holes 5 connected in the direction, blind via hole 6 connecting the outer layer wiring pattern 3b and the inner layer wiring pattern 2 adjacent to the outer layer wiring pattern 3b, three core insulating layers 100 and the three layers A metal piece housing hole 8 that is formed at a position directly under the electronic insulating material 11 that passes through the interlayer insulating layer 101 laminated on the front and back surfaces of the core insulating layer 100, and the outer layer wiring pattern 3a. 3b, and a solder resist 7 for protecting 3b.

  In such an insulating substrate 1, 9 is a metal piece, which is formed by a header method, and its electronic component connection side exposed surface 9A is a position below the position 8A of the electronic component mounting surface side opening end, more specifically, The electronic component mounting side surface A is located on the same surface as or lower than the outer surface of the outer layer wiring pattern 3a, and the radiator connection side exposed surface 9B is recessed from the position 8B of the radiator arrangement surface side opening end. More specifically, the metal piece 9 and the metal piece receiving hole are in a state of being recessed toward the position 8A of the electronic component mounting surface side opening end with respect to the outer surface of the interlayer connection layer 101 on the heat dissipating side B. The printed wiring board PW is configured by being fixedly disposed in the metal piece housing hole 8 via the adhesive 10 supplied to the gap 16 between the inner wall 8 and the inner wall 8.

  The electronic component 11 is mounted on one surface of the printed wiring board PW via the solder 13, and the heat radiating body 14 is disposed on the other surface via the heat conductive adhesive 15, so that the printed circuit board PC is mounted. It is configured. In FIG. 1, reference numeral 12 denotes a terminal drawn from the electronic component 11, and is connected to the mounting pad 3c via solder.

  Then, the manufacturing method of the said printed wiring board PW is demonstrated using FIG.2 and FIG.3.

First, the inner layer wiring pattern 2 is formed on the boundary surface and the front and back surfaces of the three core insulating layers 100 by a well-known method, and the buried hole 4 that connects the inner layer wiring pattern 2 formed on each surface in the vertical direction. To obtain the core substrate 1a.
Next, the build-up layer 1b composed of the interlayer insulating layer 101 and the metal foil 102 is laminated on the front and back surfaces of the core substrate 1a, thereby obtaining the intermediate substrate having the six-layer structure shown in FIG.

  As the core insulating layers 100 and 100a, a material in which a reinforcing fiber such as a glass cloth generally used is impregnated with a thermosetting resin such as an epoxy resin can be used, and a double-sided plate disposed in the center is used. Since a certain amount of thickness is necessary for the first formation (strength that can be applied to the production line), the core insulating layer 100 disposed in the center is 500 to 700 μm, and the core insulating layer 100a disposed above and below the core insulating layer 100a. Of 200 to 300 μm is used.

  Also in the metal foil for forming the inner layer wiring pattern, a general copper foil can be used, and the thickness thereof is 50 to 100 μm in the core insulating layer 100 disposed in the center, and the core disposed above and below the core insulating layer 100. An insulating layer 100a having a thickness of 18 to 35 μm is used.

  As a method for forming the buried hole 4, a through hole having a cutting diameter of 0.25 to 0.35 mm is drilled by drilling such as a drill, and after desmear treatment, a plating thickness of 25 μm is set for the through hole. It can be formed by performing a plating process (for example, “copper plating process”).

  As the interlayer connection layer 101 and the metal foil 102, the same materials as those used for the core substrate 1a can be used, and the thickness thereof is, for example, 60 to 100 μm for the interlayer insulating layer 101 and 9 to 18 μm for the metal foil 102.

Next, as shown in FIG. 2 (b), a laser (for example, "carbon dioxide laser") is irradiated on the portion where the blind via hole 6 is to be formed, and the cut diameter on the top side is 0.15 to 0.25 mm. The non-through hole 6a is drilled, and the through hole 5a having a cutting diameter of φ0.25 to 0.35 mm is drilled by drilling a portion where the through plating through hole 5 is to be formed.
In addition, when drilling the through-hole 5a with a drill, for example, the metal piece accommodation hole 8 with a cutting diameter of φ3.5 to 4.5 mm is also drilled together.

  Next, after the insides of the through-hole 5a, the non-through-hole 6a, and the metal piece accommodating hole 8 are cleaned by desmear treatment, electrolytic plating treatment using a plating bath for via filling, and electrolytic plating treatment using a high-throw bath Are sequentially deposited on the entire intermediate substrate including the inside of each hole (for example, “copper plating” having a thickness of 25 μm) (see FIG. 2C), and then by a well-known photo-etching process. After forming the outer layer wiring patterns 3a, 3b and the mounting pads 3c, the solder resist 7 for protecting the outer layer wiring patterns 3a, 3b is appropriately formed to obtain the insulating substrate 1 shown in FIG.

Next, although the “metal piece 9” is arranged in the metal piece accommodation hole 8, the following conditions must be satisfied in the present invention.
That is, when the electronic component connection side exposed surface 9A of the metal piece 9 is disposed at the position 8A or less of the electronic component mounting surface side opening end when it is disposed in the metal piece accommodating hole 8, more specifically, the electronic component mounting side surface A Position where the exposed surface 9B on the radiator connecting side of the metal piece 9 is recessed from the position 8B of the opening end on the radiator disposing surface side. More specifically, the condition is that the electronic component mounting surface side opening end is in a position recessed toward the position 8A side from the outer surface of the interlayer connection layer 101 on the heat dissipating element arrangement side surface B.
The position of the electronic component connection side exposed surface 9A when the metal piece 9 is disposed in the metal piece accommodation hole 8 can be compensated by a fluid solder, so even if there is some dimensional error, there is not much problem. However, it is desirable to set the depth within a range that does not affect the solder connectivity with the electronic component 11, for example, a depth of 0 to 400 μm from the position 8A of the electronic component mounting surface side opening end. Further, regarding the position of the radiator connecting side exposed surface 9B, the depth within a range that can ensure insulation between the radiator and the electronic component mounting surface side, for example, at least from the position 8B of the opening end on the radiator disposing surface side It is desirable that the position is recessed by 100 μm on the position 8A side of the opening end. On the other hand, from the viewpoint of heat dissipation, the depth within a range that can ensure the desired heat dissipation, for example, the position of the opening end on the radiator disposition surface side It is desirable to suppress the depth from 8B to 200 μm or less. In other words, it is desirable that the depth is 100 to 200 μm from the position 8B of the opening side of the radiator disposition surface side.

In the present invention, it is necessary to use the metal piece 9 formed by the header method in order to stably supply the metal piece satisfying such severe conditions (dimensional accuracy).
By the way, the header method is a method that cuts a metal rod such as copper according to the required volume and pushes it into the mold to produce the desired shape and dimensions. Compared with the punching method in which the metal plate is punched out, the mold wear hardly occurs and the metal piece 9 with high dimensional accuracy can be supplied stably.

  In order to arrange such a metal piece 9 at the above position, a jig 17 having a projection 17a having a height that can be arranged at a position recessed from the position 8B at the opening end of the metal piece accommodation hole 8 on the side of the radiator. Is prepared, the jig 17 is placed on the heat dissipating side B of the insulating substrate 1 in a state where the positions of the metal piece receiving hole 8 and the protrusion 17a are aligned, and then the metal piece 9 (header method) The formed metal piece) is inserted into the metal piece accommodation hole 8 through the protrusion 17a of the jig 17 (see FIG. 3D). Incidentally, as a means for inserting the metal piece 9, a general chip mounter or the like can be used.

  Finally, the gap 16 formed between the inner wall of the metal piece receiving hole 8 and the metal piece 9 (for example, the dimension that can be assumed when the metal piece 9 is arranged in the center of the metal piece containing hole 8 is The adhesive 10 is supplied to the metal piece 9 and the metal piece 9 is fixedly arranged in the metal piece accommodation hole 8 (see FIG. 3 (e) and FIG. 4). By removing the jig 17 disposed in B, the printed wiring board PW of the present invention shown in FIG.

The most notable point in the present invention is that the metal piece 9 arranged in the metal piece accommodating hole 8 is arranged by a header method with high dimensional accuracy.
As a result, the metal piece 9 protrudes from the position 8A of the electronic component mounting surface side opening end or the position 8B of the heat radiator disposition surface side opening end, or an infinite amount of the metal piece 9 is arranged in the metal piece accommodation hole 8. Various problems (such as poor mounting of electronic parts, heat dissipation, and reduced insulation reliability) can be solved.

Further, as a method for fixing the metal piece 9, it is also one of the features of the present invention that means for supplying the adhesive 10 to the gap 16 formed between the inner wall of the metal piece housing hole 8 and the metal piece 9 is adopted. Raised as one.
Thereby, the problem that a crack enters in the inner wall of the metal piece accommodation hole seen by the press-fitting method can be solved.

  In explaining the present invention, an example (see FIG. 4) in which the adhesive 10 for fixing the metal piece 9 is supplied to two places of the gap 16 is shown. There is no particular problem even if the adhesive is supplied to more points (including the entire circumference) as long as the adhesive can be fixed without flowing out.

In addition, as an example of the metal piece housing hole 8, a description has been given using a configuration in which the plating 103 is not formed on the inner wall, but it is of course possible to form the plating 103.
However, if the thickness variation of the plating 103 is large, the metal piece 9 may be caught on the protruding portion of the plating 103 and an insertion error may occur. Therefore, it can be said that it is desirable that the plating 103 is not formed. .

1: Insulating substrate 1a: Core substrate 1b: Build-up layer 2: Inner layer wiring pattern 3a, 3b: Outer layer wiring pattern 3c: Mounting pad 4: Bleed hole 5: Through plating through hole 5a: Through hole 6: Blind via hole 6a : Non-through hole 7: Solder resist 8: Metal piece receiving hole 8A: Position of opening end on electronic component mounting surface side 8B: Position of opening end on heat dissipator arrangement surface side 9, 99: Metal piece 9A, 99A: Electronic component connecting side Exposed surfaces 9B, 99B: radiator connecting side exposed surface 99a: concave portion 99b: convex portion 10: adhesive 11: electronic component 12: terminal 13: solder 14: heat radiator 15: thermally conductive adhesive 16: gap 100: core Insulating layer 101: Interlayer connection layer 102: Metal foil 103: Plating A: Electronic component mounting side face B: Heat dissipating element side face PW, Pw: Printed wiring board PC, Pc: Printed circuit board

Claims (4)

  A printed wiring board for transferring heat generated from an electronic component to a heat dissipating member disposed on a surface opposite to the electronic component mounting side by a metal piece disposed immediately below the electronic component, and at least insulated A metal piece housing hole penetrating the insulating substrate, and a header method-forming metal piece fixedly disposed in the metal piece housing hole with an adhesive, and the metal piece on the electronic component connection side The exposed surface is at a position below the position of the electronic component mounting surface side opening end of the metal piece housing hole, and the exposed surface of the metal piece on the radiator connecting side A printed wiring board characterized by being in a position recessed from the position.   The position below the position of the electronic component mounting surface side opening end of the metal piece accommodation hole is a depth within a range that does not affect the solder connectivity with the electronic component, and the radiator disposition surface of the metal piece accommodation hole. 2. The printed wiring board according to claim 1, wherein the position recessed from the position of the side opening end is a depth within a range in which insulation between the radiator and a desired heat dissipation property can be secured.   A method of manufacturing a printed wiring board for transferring heat generated from an electronic component to a heat dissipating member disposed on a surface opposite to the electronic component mounting side by a metal piece disposed directly below the electronic component, At least the step of forming the metal piece housing hole in the insulating substrate, and the electronic component connection side exposed surface of the metal piece when the metal piece housing hole is disposed in the metal piece housing hole, the electronic component mounting surface side opening end of the metal piece housing hole Header piece of the metal piece with a length that becomes a position below the position of the heat sink and the exposed surface of the metal piece on the radiator connecting side is recessed from the position of the opening of the metal piece containing hole on the side of the radiator arranging surface. And when the metal piece is arranged in the metal piece receiving hole, the exposed surface of the metal piece on the radiator connecting side is recessed from the position of the opening on the heat sink arranging surface side of the metal piece containing hole. Prepare a jig with a protrusion that is high enough to be placed A step of arranging the jig in a state in which the positions of the metal piece receiving holes and the protrusions are aligned with the heat dissipating member arrangement side surface of the insulating substrate, and the metal pieces are connected to the metal pieces via the protrusions of the jig. A step of inserting the metal piece into the accommodation hole, and a step of supplying an adhesive to a gap between the metal piece accommodation hole and the metal piece and fixing the metal piece in the metal piece accommodation hole. Manufacturing method of printed wiring board.   The position below the position of the electronic component mounting surface side opening end of the metal piece accommodation hole is a depth within a range that does not affect the solder connectivity with the electronic component, and the radiator disposition surface of the metal piece accommodation hole. 4. The printed wiring board according to claim 3, wherein the position recessed from the position of the side opening end is a depth within a range in which insulation between the radiator and a desired heat dissipation property can be ensured. Production method.