JP2016187052A - Printed Wiring Board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed wiring board that is hardly warped in spite of provision of a polyimide layer and a thermoplastic polyimide layer.SOLUTION: A printed wiring board includes a wiring board portion having an insulation layer and a conductor wire on the insulation layer, and an adhesion layer 4 which is disposed on the wiring board portion and covers the conductor wire. The insulation layer has a polyimide core layer and two thermoplastic polyimide cover layers which are respectively located on both the surfaces of the core layer. The adhesion layer 4 is made of thermoplastic polyimide, and the conductor wire is embedded in the adhesion layer 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a printed wiring board, and more particularly to a printed wiring board provided with an insulating layer made of polyimide.

  One of the materials for the insulating layer in the printed wiring board is polyimide. When an insulating layer is produced from polyimide, high flexibility and heat resistance can be imparted to the printed wiring board. However, if the insulating layer is formed of only polyimide, the adhesiveness between the polyimide and the metal is low, so the adhesiveness between the insulating layer and the conductor wiring may be lowered. For this reason, by providing a layer made of thermoplastic polyimide on the layer made of polyimide and providing conductor wiring on the layer made of thermoplastic polyimide, good adhesion between the insulating layer and the conductor wiring is obtained. Securing is also done.

  However, since thermoplastic polyimide has a larger thermal expansion coefficient than polyimide, if the insulating layer includes a polyimide layer and a thermoplastic polyimide layer, the printed wiring board may be warped. A technique for suppressing such warpage is disclosed in Patent Document 1. In Patent Document 1, a thermoplastic polyimide resin film for forming an insulating layer is biaxially stretched so that the thermoplastic polyimide resin is molecularly oriented isotropically in the plane direction of the film. Reducing the coefficient of thermal expansion of the film is described.

JP 2008-188792 A

  In order to adjust the thermal expansion coefficient accurately by biaxially stretching a thermoplastic polyimide resin film as described in Patent Document 1, it is necessary to optimize processing conditions such as stretching temperature, stretching ratio, stretching speed, etc. There is. However, it is not easy to simultaneously optimize such a large number of conditions. In addition, the thermal expansion coefficient of the processed thermoplastic polyimide resin film may vary due to fluctuations in material properties due to differences in production lots and the like, and fluctuations in the production environment. For this reason, the technique described in Patent Document 1 cannot effectively suppress the warpage of the printed wiring board.

  The present invention has been made in view of the above reasons, and an object of the present invention is to provide a printed wiring board which is less likely to warp despite having a polyimide layer and a thermoplastic polyimide layer.

  A printed wiring board according to the present invention includes a wiring board portion including an insulating layer and a conductor wiring on the insulating layer, and an adhesive layer on the wiring substrate portion and covering the conductor wiring, A polyimide core layer and two thermoplastic polyimide cover layers on both sides of the core layer, the adhesive layer is made of thermoplastic polyimide, and the conductor wiring is embedded in the adhesive layer It is characterized by being.

  1st aspect of the manufacturing method of the printed wiring board which concerns on this invention is equipped with the insulating layer and the conductor wiring on the said insulating layer, and the said insulating layer is on both sides of a polyimide core layer and the said core layer, respectively A resin film made of thermoplastic polyimide is placed on the base substrate provided with two thermoplastic polyimide cover layers, and a metal foil is placed on the resin film and heated. The pressing includes bonding the base substrate and the resin film, the resin film and the metal foil, and embedding the conductor wiring in the resin film.

  A second aspect of the method for manufacturing a printed wiring board according to the present invention includes an insulating layer and a conductor wiring on the insulating layer, and the insulating layer is formed on both sides of the polyimide core layer and the core layer. A resin film made of thermoplastic polyimide is arranged on a base substrate provided with two cover layers made of thermoplastic polyimide so as to cover the conductor wiring, and a resin made of thermoplastic polyimide is placed on the resin film. A multilayer resin film comprising a layer, a second core layer made of polyimide on the resin layer, and a second cover layer made of thermoplastic polyimide on the second core layer, the resin layer on the resin film The base substrate and the resin film, the resin film and the multilayer resin film, arranged by placing a metal foil on the second cover layer and heat pressing It may include embedding the conductor interconnect the multilayer resin film and the metal foil into the resin film with adhered respectively.

  A third aspect of the method for producing a printed wiring board according to the present invention includes an insulating layer and a conductor wiring on the insulating layer, and the insulating layer is formed on both sides of the polyimide core layer and the core layer. On a base substrate provided with two thermoplastic polyimide cover layers, a thermoplastic polyimide resin layer, a polyimide second core layer on the resin layer, and the second core layer A multilayer resin film comprising a second cover layer made of a certain thermoplastic polyimide is disposed so that the resin layer covers the conductor wiring, a metal foil is disposed on the second cover layer, and heated and pressed. The base substrate and the multilayer resin film, and the multilayer resin film and the metal foil are bonded to each other and the conductor wiring is embedded in the resin layer.

  A fourth aspect of the method for manufacturing a printed wiring board according to the present invention includes an insulating layer and a conductor wiring on the insulating layer, and the insulating layer is formed on both sides of the polyimide core layer and the core layer. A base substrate comprising two thermoplastic polyimide cover layers, a second insulating layer and a second conductor wiring on the second insulating layer, wherein the second insulating layer is a polyimide second core A resin film made of thermoplastic polyimide between the layer and a second base substrate comprising two thermoplastic polyimide second cover layers respectively on both sides of the second core layer, The conductor wiring and the second conductor wiring are arranged so as to cover, and the base substrate and the resin film, and the resin film and the second base substrate are bonded by heating and pressing, respectively, It includes embedding the conductor wiring and the second conductor wiring to fat film.

  According to the present invention, it is possible to obtain a printed wiring board which is less likely to warp despite having a polyimide layer and a thermoplastic polyimide layer.

1A is a cross-sectional view showing a printed wiring board according to the first embodiment of the present invention, and FIG. 1B is a cross-sectional view showing an example of a method for manufacturing the printed wiring board shown in FIG. 1A. 2A is a cross-sectional view showing a printed wiring board according to a second embodiment of the present invention, FIG. 2B is a cross-sectional view showing a first example of a method for manufacturing the printed wiring board shown in FIG. 2A, and FIG. 2C is a printed wiring board shown in FIG. It is sectional drawing which shows the 2nd example of the manufacturing method of a board. FIG. 3A is a cross-sectional view showing a printed wiring board according to the third embodiment of the present invention, and FIG. 3B is a cross-sectional view showing an example of a method for manufacturing the printed wiring board shown in FIG. 3A.

  FIG. 1A shows a printed wiring board according to the first embodiment of the present invention. This printed wiring board includes an insulating layer 11 (hereinafter referred to as a first insulating layer 11) and a wiring board part 31 (hereinafter referred to as a first conductive wiring 21) provided on the first insulating layer 11 (hereinafter referred to as a first conductor wiring 21). And the first wiring board portion 31) and the adhesive layer 4 that is on the first wiring board portion 31 and covers the first conductor wiring 21. The first insulating layer 11 includes a polyimide core layer 51 (hereinafter referred to as the first core layer 51) and two thermoplastic polyimide cover layers 611 and 612 (hereinafter referred to as the first core layer 51). And first cover layers 611 and 612). The adhesive layer 4 is made of thermoplastic polyimide. A first conductor wiring 21 is embedded in the adhesive layer 4. In the first embodiment, the printed wiring board further includes a metal layer 72 (hereinafter referred to as a second metal layer 72) on the adhesive layer 4. The 1st wiring board part 31, the contact bonding layer 4, and the 2nd metal layer 72 are laminated | stacked in this order.

  In the first embodiment, although the first insulating layer 11 in the printed wiring board includes the first cover layers 611 and 612 made of thermoplastic polyimide, the printed wiring board also includes the adhesive layer 4 made of thermoplastic polyimide. The imbalance of the thermal expansion coefficient between 4 and the first insulating layer 11 is suppressed. Thereby, the curvature of a printed wiring board is suppressed.

  The printed wiring board according to the first embodiment will be described in more detail. As described above, the first wiring board portion 31 includes the first insulating layer 11 and the first conductor wiring 21 on the first insulating layer 11. In the first embodiment, the first wiring board portion 31 also includes a metal layer (hereinafter referred to as a first metal layer 71) on the surface of the first insulating layer 11 opposite to the first conductor wiring 21.

  The first conductor wiring 21 in the first wiring board portion 31 is made of, for example, copper. The surface in contact with the adhesive layer 4 in the first conductor wiring 21 is preferably roughened. In this case, the adhesion between the first conductor wiring 21 and the adhesive layer 4 is particularly high. The first conductor wiring 21 is preferably subjected to at least one of a metal plating process and a chromate process. In this case, high adhesion is provided between the first conductor wiring 21 and the adhesive layer 4. For this reason, even when the first conductor wiring 21 and the adhesive layer 4 are heated at the time of manufacturing a printed wiring board, the first conductor wiring 21 and the adhesive layer 4 are bonded to each other due to the difference in coefficient of linear expansion between the first conductor wiring 21 and the adhesive layer 4. Separation from the layer 4 is suppressed. Thereby, high heat resistance is imparted to the first conductor wiring 21. The metal plating treatment preferably includes at least one of galvanization treatment, tin plating treatment, nickel plating treatment, molybdenum plating treatment, and cobalt plating treatment. In this case, particularly high adhesion is provided between the first conductor wiring 21 and the adhesive layer 4. The thickness of the first conductor wiring 21 is, for example, in the range of 2 to 35 μm.

  The first insulating layer 11 in the first wiring board portion 31 includes the first core layer 51 made of polyimide as described above, and therefore the first insulating layer 11 has high flexibility and heat resistance. The thickness of the first core layer 51 is, for example, in the range of 5 to 200 μm.

  As described above, the first insulating layer 11 includes the two first cover layers 611 and 612 made of thermoplastic polyimide on the both surfaces of the first core layer 51. Thereby, one first cover layer 611 of the two first cover layers 611 and 612 is interposed between the polyimide first core layer 51 and the first conductor wiring 21, and the first cover layer 611 is Contact the first conductor wiring 21. For this reason, high adhesiveness is obtained between the first insulating layer 11 and the first conductor wiring 21. Further, between the first core layer 51 made of polyimide and the first metal layer 71, a first cover layer 612 that is not in contact with the conductor wiring 21 among the two first cover layers 611 and 612 is interposed. The layer 612 is in contact with the first metal layer 71. For this reason, high adhesion is also obtained between the first insulating layer 11 and the first metal layer 71. It is preferable that the glass transition point of each 1st cover layer 611,612 exists in the range of 150-300 degreeC. In this case, while ensuring the high heat resistance of the 1st insulating layer 11, the high adhesiveness of the 1st insulating layer 11 and the 1st conductor wiring 21 is ensured, Furthermore, the 1st insulating layer 11 and the 1st metal layer 71, High adhesion can be secured. It is particularly preferable if the glass transition points of the first cover layers 611 and 612 are in the range of 220 to 320 ° C. The thickness of each first cover layer 611, 612 is, for example, in the range of 1-15 μm.

  The polyimide that is the material of the first core layer 51 refers to a polyimide that does not proceed with curing when heated, but does not have a property of being softened when heated. This polyimide is obtained, for example, by dehydrating and curing polyamic acid obtained from pyromellitic dianhydride and 4,4'-diaminodiphenyl ether. Specific examples of polyimide include trade name “Kapton” (manufactured by Toray DuPont, DuPont).

  The thermoplastic polyimide that is the material of the first cover layers 611 and 612 refers to a polyimide that produces plasticity when heated. Examples of the thermoplastic polyimide include a polyimide having a low intermolecular cohesion due to a low concentration of imide groups in the repeating unit.

  The first metal layer 71 is made of, for example, copper. The thickness of the first metal layer 71 is, for example, in the range of 2 to 70 μm.

  Since the adhesive layer 4 made of thermoplastic polyimide is on the first wiring board portion 31 and covers the first conductor wiring 21, warping of the printed wiring board is suppressed as described above. Further, since the adhesive layer 4 is made of thermoplastic polyimide, the adhesive layer 4 can easily follow the shape of the first conductor wiring 21. For this reason, the 1st conductor wiring 21 is easily embedded in the contact bonding layer 4, and flattening of a printed wiring board is easy. Further, since the adhesive layer 4 is made of thermoplastic polyimide, the adhesiveness between the adhesive layer 4 and the first conductor wiring 21 is high. Furthermore, since the adhesive layer 4 is in contact with the first cover layer 611 in the first insulating layer 11 and the adhesive layer 4 and the first cover layer 611 are both made of thermoplastic polyimide, the adhesive layer 4 and the first insulating layer 11 High adhesion.

  The glass transition point of the adhesive layer 4 is preferably in the range of 150 to 300 ° C. In this case, while ensuring high heat resistance in the whole printed wiring board, high adhesion between the adhesive layer 4 and the first conductor wiring 21 is ensured, and high adhesion between the adhesive layer 4 and the second metal layer 72 is also achieved. Can be secured. Furthermore, it is particularly easy to embed the first conductor wiring 21 in the adhesive layer 4 by causing the shape of the adhesive layer 4 to follow the shape of the first conductor wiring 21 during manufacture of the printed wiring board. Is particularly easy. It is particularly preferable if the glass transition point of the adhesive layer 4 is in the range of 200 to 280 ° C. The thickness of the adhesive layer 4 is in the range of 5 to 100 μm, for example.

  The second metal layer 72 is made of, for example, copper. The thickness of the second metal layer 72 is, for example, in the range of 2 to 70 μm.

  In 1st embodiment, you may form a conductor wiring in a printed wiring board by performing the etching process etc. to the 1st metal layer 71 in a printed wiring board. Moreover, you may form a conductor wiring in a printed wiring board by giving the etching process etc. to the 2nd metal layer 72 in a printed wiring board. One or both of the first metal layer 71 and the second metal layer 72 may be used as a ground layer as they are.

  In the first embodiment, a semiconductor chip may be mounted on the printed wiring board. In this case, the semiconductor chip and the printed wiring board may be electrically connected by a wire bonding method. Thus, when mounting a semiconductor chip on a printed wiring board, even if the printed wiring board is partially heated by wire bonding, the first insulating layer 11 and the adhesive layer 4 have high heat resistance. Is less likely to cause unevenness due to partial softening of the first insulating layer 11 and the adhesive layer 4. For this reason, it is easy to mount the semiconductor chip on the printed wiring board.

  An example of a method for manufacturing a printed wiring board in the first embodiment will be described with reference to FIG. 1B.

  First, a base substrate 310 (hereinafter referred to as a first base substrate 310) is prepared. The first base substrate 310 includes a first insulating layer 11 and a first conductor wiring 21 on the first insulating layer 11. The first base substrate 310 further includes a first metal layer 71 on the surface of the first insulating layer 11 opposite to the first conductor wiring 21. The first insulating layer 11 includes a first core layer 51 made of polyimide, and two cover layers 611 and 612 made of thermoplastic polyimide respectively on both surfaces of the first core layer 51. The first base substrate 310 is obtained, for example, by performing an etching process on one of two metal foils in a double-sided metal-clad laminate including the first insulating layer 11 and two metal foils respectively on both sides thereof.

  Next, a resin film 40 made of thermoplastic polyimide is disposed on the first base substrate 310 so as to cover the first conductor wiring 21. A metal foil 720 is disposed on the resin film 40. The metal foil 720 is a copper foil, for example.

  Next, the first base substrate 310 and the resin film 40 and the resin film 40 and the metal foil 720 are bonded to each other and the first conductor wiring 21 is embedded in the resin film 40 by heat pressing. Thereby, the adhesive layer 4 is formed from the resin film 40, and the second metal layer 72 is formed from the metal foil metal foil 720. Thereby, the printed wiring board in the first embodiment is obtained.

  In this manufacturing method, the first conductor wiring 21 is easily embedded in the resin film 40 because the resin film 40 is softened during the heating press. This makes it easy to flatten the printed wiring board. When the glass transition point of the resin film 40 is in the range of 150 to 300 ° C, the heating temperature in the heating press is preferably in the range of 250 to 400 ° C. In this case, the adhesive layer 4 having a glass transition point in the range of 150 to 300 ° C. is formed, and particularly high heat resistance is imparted to the printed wiring board. Furthermore, the first conductor wiring 21 is particularly easily embedded in the resin film 40 at the time of hot pressing, so that it is particularly easy to flatten the printed wiring board. It is more preferable if the heating temperature is higher than the glass transition point, and it is more preferable if the temperature difference between the glass transition point and the heating temperature is 80 ° C. or more.

  FIG. 2A shows a printed wiring board according to the second embodiment of the present invention. This printed wiring board includes a first wiring board portion 31 including a first insulating layer 11 and a first conductor wiring 21 on the first insulating layer 11, and a first conductor wiring 21 on the first wiring board portion 31. And an adhesive layer 4 covering. The first insulating layer 11 includes a first core layer 51 made of polyimide, and two cover layers 611 and 612 made of thermoplastic polyimide respectively on both surfaces of the first core layer 51. The adhesive layer 4 is made of thermoplastic polyimide. A first conductor wiring 21 is embedded in the adhesive layer 4. In the second embodiment, the printed wiring board further includes a polyimide second core layer 52 on the adhesive layer 4 and a thermoplastic polyimide second cover layer 62 on the second core layer 52. . The printed wiring board further includes a second metal layer 72 on the second cover layer 62. The 1st wiring board part 31, the contact bonding layer 4, the 2nd core layer 52, the 2nd cover layer 62, and the 2nd metal layer 72 are laminated | stacked in this order.

  The polyimide that is the material of the second core layer 52, like the polyimide that is the material of the first core layer 51, does not proceed with curing when heated, but has the property of softening when heated. This refers to polyimide that has not been used. The thermoplastic polyimide that is the material of the second cover layer 62 refers to a polyimide that generates plasticity when heated, similarly to the thermoplastic polyimide that is the material of the first cover layers 611 and 612.

  In the second embodiment, although the first insulating layer 11 in the printed wiring board includes the first cover layers 611 and 612 made of thermoplastic polyimide, the printed wiring board also includes the adhesive layer 4 made of thermoplastic polyimide. The imbalance of the thermal expansion coefficient between 4 and the first insulating layer 11 is suppressed. Furthermore, in the second embodiment, a first cover layer 611 made of thermoplastic polyimide, a first core layer 51 made of polyimide, and a first cover layer 612 made of thermoplastic polyimide are sequentially laminated on one surface of the first conductor wiring 21. At the same time, an adhesive layer 4 made of thermoplastic polyimide, a second core layer 52 made of polyimide, and a second cover layer 62 made of thermoplastic polyimide are sequentially laminated on the other surface of the first conductor wiring 21. That is, a layer made of thermoplastic polyimide, a layer made of polyimide, and a layer made of thermoplastic polyimide are sequentially laminated on one surface and the other surface of the first conductor wiring 21. For this reason, the imbalance of a thermal expansion coefficient is further suppressed in the whole printed wiring board. Thereby, the curvature of a printed wiring board is suppressed remarkably. Furthermore, by providing the second core layer 52 made of polyimide, extremely high heat resistance is imparted to the printed wiring board.

  The printed wiring board according to the second embodiment will be described in more detail. As described above, the first wiring board portion 31 includes the first insulating layer 11 and the first conductor wiring 21 on the first insulating layer 11. In the first embodiment, the first wiring board portion 31 also includes a first metal layer 71 on the surface of the first insulating layer 11 opposite to the first conductor wiring 21. The first wiring board part 31 may have the same configuration as the first wiring board part 31 in the first embodiment. The adhesive layer 4 in the second embodiment may have the same configuration as the adhesive layer 4 in the first embodiment.

  Similar to the first core layer 51, the second core layer 52 is made of polyimide. For this reason, as above-mentioned, the curvature of a printed wiring board is suppressed remarkably. The thickness of the second core layer 52 is, for example, in the range of 5 to 200 μm.

  As described above, the second cover layer 62 made of thermoplastic polyimide is provided on the second core layer 52. Thereby, the second cover layer 62 made of thermoplastic polyimide is interposed between the second core layer 52 made of polyimide and the second metal layer 72, and the second cover layer 62 is in contact with the second metal layer 72. For this reason, high adhesiveness is obtained between the second metal layer 72 and the second cover layer 62, and high adhesiveness is also obtained between the second cover layer 62 and the second core layer 52. Thereby, delamination in a printed wiring board is suppressed. The glass transition point of the second cover layer 62 is preferably in the range of 150 to 300 ° C. In this case, high adhesion between the second cover layer 62 and the second metal layer 72 can be ensured while ensuring high heat resistance of the printed wiring board. It is particularly preferable if the glass transition point of the second cover layer 62 is in the range of 220 to 320 ° C. The thickness of the second cover layer 62 is, for example, in the range of 1 to 15 μm.

  The second metal layer 72 is made of, for example, copper. The thickness of the second metal layer 72 is, for example, in the range of 2 to 70 μm.

  Also in the second embodiment, conductor wiring may be formed on the printed wiring board by performing an etching process or the like on the first metal layer 71 in the printed wiring board. Conductor wiring may be formed on the printed wiring board by subjecting the second metal layer 72 of the printed wiring board to an etching process or the like. One or both of the first metal layer 71 and the second metal layer 72 may be used as a ground layer as they are.

  Also in the second embodiment, a semiconductor chip may be mounted on the printed wiring board. In the second embodiment, even if the printed wiring board is partially heated by wire bonding, the printed wiring board has high heat resistance. Therefore, the printed wiring board has unevenness due to partial softening of the first insulating layer 11 and the like. Is unlikely to occur. For this reason, it is easy to mount the semiconductor chip on the printed wiring board.

  The 1st example of the manufacturing method of the printed wiring board in 2nd embodiment is demonstrated with reference to FIG. 2B.

  First, the first base substrate 310 is prepared. The first base substrate 310 includes a first insulating layer 11, a first conductor wiring 21, and a first metal layer 71, and the first insulating layer 11 is formed on both surfaces of the first core layer 51 and the first core layer 51. Are provided with first cover layers 611 and 612, respectively. The first base substrate 310 may have the same configuration as the first base substrate 310 in the first embodiment.

  Next, a resin film 40 made of thermoplastic polyimide is disposed on the first base substrate 310 so as to cover the first conductor wiring 21.

  A multilayer resin film 91 is disposed on the resin film 40. The multilayer resin film 91 includes a resin layer 81 made of thermoplastic polyimide, a second core layer 52 made of polyimide on the resin layer 81, and a second cover layer 62 made of thermoplastic polyimide on the second core layer 52. With. The multilayer resin film 91 is disposed on the resin film 40 so that the resin layer 81 in the multilayer resin film 91 is in contact with the resin film 40. The thickness of the resin layer 81 in the multilayer resin film 91 is, for example, in the range of 1 to 15 μm.

  A metal foil 720 is disposed on the second cover layer 62 in the multilayer resin film 91. The metal foil 720 is a copper foil, for example.

  Next, the first base substrate 310 and the resin film 40, the resin film 40 and the multilayer resin film 91, and the multilayer resin film 91 and the metal foil 720 are bonded to each other and the first conductor wiring is attached to the resin film 40 by heating and pressing. 21 is embedded. Thereby, the adhesive layer 4 is formed from the resin film 40 and the resin layer 81, and the second metal layer 72 is formed from the metal foil 720. Thereby, the printed wiring board in the second embodiment is obtained.

  In this manufacturing method, the first conductor wiring 21 is easily embedded in the resin layer 81 because the resin film 40 is softened during the heating press. For this reason, it is easy to flatten the printed wiring board. When the glass transition point of the resin film 40 is in the range of 150 to 300 ° C, the heating temperature in the heating press is preferably in the range of 250 to 400 ° C. In this case, the adhesive layer 4 having a glass transition point in the range of 150 to 300 ° C. is formed, and particularly high heat resistance is imparted to the printed wiring board. Furthermore, the first conductor wiring 21 is particularly easily embedded in the resin film 40 at the time of hot pressing, so that it is particularly easy to flatten the printed wiring board.

  A second example of the printed wiring board manufacturing method in the second embodiment will be described with reference to FIG. 2C.

  First, the first base substrate 310 is prepared as in the first example.

  Next, the multilayer resin film 92 is disposed on the first base substrate 310. The multilayer resin film 92 includes a resin layer 82 made of thermoplastic polyimide, a second core layer 52 made of polyimide on the resin layer 82, and a second cover layer 62 made of thermoplastic polyimide on the second core layer 52. With. The multilayer resin film 92 is disposed on the first base substrate 310 so that the resin layer 82 in the multilayer resin film 92 covers the first conductor wiring 21 in the first base substrate 310. In the second example, the thickness of the resin layer 82 in the multilayer resin film 92 is, for example, in the range of 5 to 100 μm.

  A metal foil 720 is disposed on the second cover layer 62 in the multilayer resin film 92. The metal foil 720 is a copper foil, for example.

  Next, the first base substrate 310 and the multilayer resin film 92, and the multilayer resin film 92 and the metal foil 720 are bonded to each other and the first conductor wiring 21 is embedded in the resin layer 82 by heating and pressing. Thereby, the adhesive layer 4 is formed from the resin layer 82, and the second metal layer 72 is formed from the metal foil 720. Thereby, the printed wiring board in the second embodiment is obtained.

  In this manufacturing method, the first conductor wiring 21 is easily embedded in the resin layer 82 because the resin layer 82 is softened during the heat pressing. For this reason, it is easy to flatten the printed wiring board. When the glass transition point of the resin layer 82 is in the range of 150 to 300 ° C, the heating temperature in the heating press is preferably in the range of 250 to 400 ° C. In this case, the adhesive layer 4 having a glass transition point in the range of 150 to 300 ° C. is formed, and particularly high heat resistance is imparted to the printed wiring board. Furthermore, the first conductor wiring 21 is particularly easily embedded in the resin layer 82 during hot pressing, and thus the printed wiring board is particularly easily flattened.

  FIG. 3A shows a printed wiring board according to the third embodiment of the present invention. This printed wiring board includes a first wiring board portion 31 including a first insulating layer 11 and a first conductor wiring 21 on the first insulating layer 11, and a first conductor wiring 21 on the first wiring board portion 31. And an adhesive layer 4 covering. The first insulating layer 11 includes a first core layer 51 made of polyimide, and two cover layers 611 and 612 made of thermoplastic polyimide respectively on both surfaces of the first core layer 51. The adhesive layer 4 is made of thermoplastic polyimide. A first conductor wiring 21 is embedded in the adhesive layer 4. In the third embodiment, the printed wiring board further includes a second wiring board portion 32 on the adhesive layer 4. The 1st wiring board part 31, the contact bonding layer 4, and the 2nd wiring board part 32 are laminated | stacked in this order. The second wiring board portion 32 includes a second insulating layer 12 and a second conductor wiring 22 on the second insulating layer 12. The second insulating layer 12 includes a second core layer 52 made of polyimide and two cover layers 621 and 622 made of thermoplastic polyimide respectively on both surfaces of the second core layer 52. The second conductor wiring 22 is embedded in the adhesive layer 4.

  In the third embodiment, although the first insulating layer 11 in the printed wiring board includes the first cover layers 611 and 612 made of thermoplastic polyimide, the printed wiring board also includes the adhesive layer 4 made of thermoplastic polyimide. The imbalance of the thermal expansion coefficient between 4 and the first insulating layer 11 is suppressed. In addition, although the second insulating layer 12 in the printed wiring board includes the second cover layers 621 and 622 made of thermoplastic polyimide, the printed wiring board also includes the adhesive layer 4 made of thermoplastic polyimide. An imbalance in the thermal expansion coefficient with the insulating layer 12 is also suppressed. Furthermore, in the third embodiment, the first conductor wiring 21, the first cover layer 611 made of thermoplastic polyimide, the first core layer 51 made of polyimide, and the first cover layer made of thermoplastic polyimide are formed on one surface of the adhesive layer 4. 612 are sequentially laminated, and the second conductor wiring 22, the second cover layer 621 made of thermoplastic polyimide, the second core layer 52 made of polyimide, and the second cover layer made of thermoplastic polyimide are formed on the other surface of the adhesive layer 4. 622 is sequentially stacked. That is, a thermoplastic polyimide layer, a polyimide layer, and a thermoplastic polyimide layer are sequentially laminated on one side and the other side of the adhesive layer 4. For this reason, the imbalance of a thermal expansion coefficient is further suppressed in the whole printed wiring board. Thereby, the curvature of a printed wiring board is suppressed remarkably.

  The printed wiring board according to the third embodiment will be described in more detail. As described above, the first wiring board portion 31 includes the first insulating layer 11 and the first conductor wiring 21 on the first insulating layer 11. In the third embodiment, the first wiring board portion 31 also includes a first metal layer 71 on the surface of the first insulating layer 11 opposite to the first conductor wiring 21. The first wiring board part 31 may have the same configuration as the first wiring board part 31 in the first embodiment.

  The adhesive layer 4 in the third embodiment may have the same configuration as the adhesive layer 4 in the first embodiment.

  As described above, the second wiring board portion 32 includes the second insulating layer 12 and the second conductor wiring 22 on the second insulating layer 12. In the third embodiment, the second wiring board portion 32 also includes a second metal layer 72 on the surface of the second insulating layer 12 opposite to the second conductor wiring 22.

  The second conductor wiring 22 in the second wiring board portion 32 is made of, for example, copper. The surface in contact with the adhesive layer 4 in the second conductor wiring 22 is preferably roughened. In this case, the adhesion between the second conductor wiring 22 and the adhesive layer 4 is particularly high. The second conductor wiring 22 is preferably subjected to a metal plating process. In this case, the heat resistance of the second conductor wiring 22 is increased. The metal plating treatment preferably includes at least one of a chromate plating treatment, a zinc plating treatment, a tin plating treatment, a nickel plating treatment, a molybdenum plating treatment, and a cobalt plating treatment. The thickness of the second conductor wiring 22 is in the range of 2 to 70 μm, for example.

  The second insulating layer 12 in the second wiring board portion 32 includes the second core layer 52 made of polyimide as described above, and therefore the second insulating layer 12 has high flexibility and heat resistance. The thickness of the second core layer 52 is, for example, in the range of 5 to 200 μm.

  As described above, the second insulating layer 12 includes the two cover layers 621 and 622 made of thermoplastic polyimide respectively on both surfaces of the second core layer 52. Accordingly, the second cover layer 621 is interposed between the polyimide second core layer 52 and the second conductor wiring 22, and the second cover layer 621 is in contact with the second conductor wiring 22. For this reason, high adhesion is obtained between the second insulating layer 12 and the second conductor wiring 22. Furthermore, a second cover layer 622 made of thermoplastic polyimide is interposed between the second core layer 52 made of polyimide and the second metal layer 72, and the second cover layer 622 is in contact with the second metal layer 72. For this reason, high adhesion is also obtained between the second insulating layer 12 and the second metal layer 72. It is preferable that the glass transition point of each 2nd cover layer 621,622 is in the range of 150-300 degreeC. In this case, while ensuring high heat resistance of the second insulating layer 12, high adhesion between the second insulating layer 12 and the second conductor wiring 22 is also ensured, and further, the second insulating layer 12 and the second metal layer 72 are High adhesion can be secured. It is particularly preferable if the glass transition points of the second cover layers 621 and 622 are in the range of 220 to 320 ° C. The thicknesses of the second cover layers 621 and 622 are, for example, in the range of 1 to 15 μm.

  The second metal layer 72 is made of, for example, copper. The thickness of the second metal layer 72 is, for example, in the range of 2 to 70 μm.

  In the third embodiment, the adhesive layer 4 made of thermoplastic polyimide is between the first wiring board portion 31 and the second wiring board portion 32 and covers the first conductor wiring 21 and the second conductor wiring 22. As described above, warping of the printed wiring board is suppressed. Further, since the adhesive layer 4 is made of thermoplastic polyimide, the adhesive layer 4 can easily follow the shapes of the first conductor wiring 21 and the second conductor wiring 22. For this reason, the first conductor wiring 21 and the second conductor wiring 22 are easily embedded in the adhesive layer 4. For this reason, it is easy to flatten the printed wiring board. Further, since the adhesive layer 4 is made of thermoplastic polyimide, the adhesiveness between the adhesive layer 4 and the first conductor wiring 21 and the adhesiveness between the adhesive layer 4 and the second conductor wiring 22 are high. Further, since the adhesive layer 4 is in contact with the first cover layer 611 in the first insulating layer 11 and the adhesive layer 4 and the first cover layer 611 are both made of thermoplastic polyimide, the adhesive layer 4 and the first insulating layer 11 High adhesion. Furthermore, since the adhesive layer 4 also contacts the second cover layer 621 in the second insulating layer 12 and both the adhesive layer 4 and the second cover layer 621 are made of thermoplastic polyimide, the adhesive layer 4 and the second insulating layer 12 Adhesion with is high.

  Also in the third embodiment, conductor wiring may be formed on the printed wiring board by performing an etching process or the like on the first metal layer 71 in the printed wiring board. Moreover, you may form a conductor wiring in a printed wiring board by giving the etching process etc. to the 2nd metal layer 72 in a printed wiring board. One or both of the first metal layer 71 and the second metal layer 72 may be used as a ground layer as they are.

  Also in the third embodiment, a semiconductor chip may be mounted on the printed wiring board. In the third embodiment, even if the printed wiring board is partially heated by wire bonding, the printed wiring board has high heat resistance. Therefore, the printed wiring board includes the first insulating layer 11, the second insulating layer 12, and the like. Unevenness due to partial softening hardly occurs. For this reason, it is easy to mount the semiconductor chip on the printed wiring board.

  The printed wiring board in the third embodiment may be further multilayered. For example, in the third embodiment, conductor wiring similar to the first and second conductor wirings 21 and 22, another adhesive layer similar to the adhesive layer 4, first and second on the second insulating layer 12. Conductor wiring similar to the conductor wirings 21 and 22 and insulating layers similar to the first and second insulating layers 11 and 12 may be sequentially laminated. On the second insulating layer 12, a plurality of laminated bodies composed of a conductor wiring, an adhesive layer, a conductor wiring, and an insulating layer may be stacked. Even in these cases, the printed wiring board is unlikely to warp despite the fact that the printed wiring board includes a polyimide layer and a thermoplastic polyimide layer.

  A printed wiring board manufacturing method according to the third embodiment will be described with reference to FIG. 3A.

  First, the first base substrate 310 and the second base substrate 320 are prepared. The first base substrate 310 includes a first insulating layer 11, a first conductor wiring 21, and a first metal layer 71, and the first insulating layer 11 is formed on both surfaces of the first core layer 51 and the first core layer 51. Are provided with first cover layers 611 and 612, respectively. The first base substrate 310 may have the same configuration as the first base substrate 310 in the first embodiment. The second base substrate 320 includes the second insulating layer 12 and the second conductor wiring 22 on the second insulating layer 12. The second base substrate 320 further includes a second metal layer 72 on the surface of the second insulating layer 12 opposite to the first conductor wiring 21. The second insulating layer 12 includes a second core layer 52 made of polyimide and two cover layers 621 and 622 made of thermoplastic polyimide respectively on both surfaces of the second core layer 52. The second base substrate 320 is obtained, for example, by performing an etching process on one of the two metal foils in the double-sided metal-clad laminate including the second insulating layer 12 and two metal foils respectively on both surfaces thereof. .

  Next, a resin film 40 made of thermoplastic polyimide is disposed between the first base substrate 310 and the second base substrate 320 so as to cover the first conductor wiring 21 and the second conductor wiring 22 with the resin film 40. To do.

  Next, the first base substrate 310 and the resin film 40 and the resin film 40 and the second base substrate 320 are bonded to each other by heating and pressing, and the first conductor wiring 21 and the second conductor wiring 22 are attached to the resin film 40. Embed. Thereby, the adhesive layer 4 is formed from the resin film 40. Thereby, the printed wiring board in the third embodiment is obtained.

  In this manufacturing method, the first conductor wiring 21 and the second conductor wiring 22 are easily embedded in the resin film 40 because the resin film 40 is softened at the time of hot pressing. For this reason, it is easy to flatten the printed wiring board. When the glass transition point of the resin film 40 is in the range of 150 to 300 ° C, the heating temperature in the heating press is preferably in the range of 250 to 400 ° C. In this case, the adhesive layer 4 having a glass transition point in the range of 150 to 300 ° C. is formed, and particularly high heat resistance is imparted to the printed wiring board. Furthermore, the first conductor wiring 21 and the second conductor wiring 22 are particularly easily embedded in the resin film 40 at the time of hot pressing, so that it is particularly easy to flatten the printed wiring board.

[Example 1]
On both sides of a multilayer film (Kaneka, product name Pixio) each comprising a polyimide layer and two thermoplastic polyimide layers on both sides of this layer, respectively, a copper foil made of Mitsui Metal (product number VLP) ) Was placed. Then, the copper foil was thermocompression bonded to the multilayer film by heat-pressing under conditions of a temperature of 360 ° C., a press pressure of 3.9 MPa (40 kg / cm ² ), and a treatment time of 5 minutes. This obtained the double-sided copper clad laminated board. Conductive wiring was formed by performing an etching process on one of the two copper foils in the double-sided copper-clad laminate. As a result, a base substrate was obtained.

A copper layer was formed by performing copper plating on the conductor wiring on the base substrate. Subsequently, a zinc-nickel alloy plating layer was formed on the copper layer by performing a zinc-nickel plating treatment. The zinc atomic weight in this galvanized layer was 10 mg / m ² . Subsequently, a zinc-tin alloy plating layer was formed on the zinc plating layer by performing a zinc-tin plating treatment. The zinc atomic weight in this zinc-tin alloy plating layer was 5 mg / m ² and the tin atomic weight was 5 mg / m ² . Subsequently, the base substrate was washed with water and then treated with chromic anhydride to form a chromate layer on the zinc-tin alloy plating layer. The chromium atomic weight in the chromate layer was 5 mg / m ² .

Subsequently, a thermoplastic polyimide film (product name: Kapton KJ, manufactured by Toray DuPont) having a glass transition point of 230 ° C. and a copper foil were sequentially laminated on the surface of the base substrate having the conductor wiring. Subsequently, the base substrate and the thermoplastic polyimide film, and the thermoplastic polyimide film and the copper foil were bonded to each other by a heat press under conditions of a temperature of 360 ° C., a press pressure of 3.9 MPa (40 kg / cm ² ), and a processing time of 5 minutes. did. Thereby, a printed wiring board having the structure shown in FIG. 1 was obtained.

[Example 2]
A base substrate was obtained in the same manner as in Example 1. The nickel-cobalt alloy plating layer was formed by performing nickel-cobalt treatment on the conductor wiring in the base substrate. The nickel atomic weight in the nickel-cobalt alloy plating layer was 20 mg / m ² , and the cobalt atomic weight was 14 mg / m ² . Subsequently, a molybdenum-cobalt plating process was performed to form a molybdenum-cobalt alloy plating layer on the nickel-cobalt alloy plating layer. The molybdenum atomic weight in the molybdenum-cobalt alloy plating layer was 70 mg / m ² , and the cobalt atomic weight was 5 mg / m ² .

Subsequently, a thermoplastic polyimide film (product name: Kapton KJ, manufactured by Toray DuPont) having a glass transition point of 230 ° C. and a copper foil were sequentially laminated on the surface of the base substrate having the conductor wiring. Subsequently, the base substrate and the thermoplastic polyimide film, and the thermoplastic polyimide film and the copper foil were bonded to each other by a heat press under conditions of a temperature of 360 ° C., a press pressure of 3.9 MPa (40 kg / cm ² ), and a processing time of 5 minutes. did. Thereby, a printed wiring board having the structure shown in FIG. 1 was obtained.

[Example 3]
A base substrate was obtained in the same manner as in Example 1. The conductor wiring on the base substrate was subjected to the same plurality of plating treatments and chromate treatments as in Example 1.

Subsequently, a thermoplastic polyimide film (made by Toray DuPont, trade name Kapton KJ) having a glass transition point of 230 ° C., a polyimide layer, and both sides of this layer on the surface of the base substrate having the conductor wiring A multilayer film (manufactured by Kaneka, trade name Pixio) having two thermoplastic polyimide layers each and a copper foil were sequentially laminated. Subsequently, the base substrate and the thermoplastic polyimide film, the thermoplastic polyimide film and the multilayer film, and the multilayer film were heated and pressed at a temperature of 360 ° C., a press pressure of 3.9 MPa (40 kg / cm ² ), and a treatment time of 5 minutes. Each copper foil was bonded. As a result, a printed wiring board having the structure shown in FIG. 2 was obtained.

[Example 4]
A base substrate was obtained in the same manner as in Example 1. The conductor wiring on the base substrate was subjected to the same plurality of plating treatments and chromate treatments as in Example 1.

Subsequently, a thermoplastic polyimide film (made by Toray DuPont, trade name Kapton KJ) having a glass transition point of 230 ° C., a polyimide layer, and both sides of this layer on the surface of the base substrate having the conductor wiring A multilayer film (made by Ube Industries, trade name Iupilex), each having two thermoplastic polyimide layers, and a copper foil were sequentially laminated. Subsequently, the base substrate and the thermoplastic polyimide film, the thermoplastic polyimide film and the multilayer film, and the multilayer film were heated and pressed at a temperature of 360 ° C., a press pressure of 3.9 MPa (40 kg / cm ² ), and a treatment time of 5 minutes. Each copper foil was bonded. As a result, a printed wiring board having the structure shown in FIG. 2 was obtained.

[Example 5]
A first base substrate and a second base substrate were obtained in the same manner as in Example 1. The same plurality of plating treatments and chromate treatments as in Example 1 were performed on the conductor wiring in each base substrate.

Between the first base substrate and the second base substrate, a thermoplastic polyimide film having a glass transition point of 230 ° C. (product name: Kapton KJ, manufactured by Toray DuPont) is used for the conductor wiring of each base substrate with this thermoplastic polyimide film. It was arranged so as to cover. Subsequently, the first base substrate and the thermoplastic polyimide film, as well as the thermoplastic polyimide film and the second base substrate were heated and pressed under conditions of a temperature of 360 ° C., a press pressure of 3.9 MPa (40 kg / cm ² ), and a processing time of 5 minutes. Were bonded to each other. As a result, a printed wiring board having the structure shown in FIG. 3 was obtained.

[Example 6]
A multilayer film (manufactured by Kaneka, trade name Pixio) comprising a polyimide layer and two thermoplastic polyimide layers respectively on both sides of this layer was prepared. Two copper foils (manufactured by Mitsui Metals, product number VLP) having a mat surface and subjected to zinc-nickel alloy plating treatment and chromate treatment on the mat surface were also prepared. Copper foils were arranged on both sides of the multilayer film so that the mat surface of each copper foil faced the opposite side of the multilayer film. Otherwise, the double-sided copper-clad laminate was obtained in the same manner as in Example 1. Conductive wiring was formed by performing an etching process on one of the two copper foils in the double-sided copper-clad laminate. As a result, a base substrate was obtained.

Subsequently, a thermoplastic polyimide film (product name: Kapton KJ, manufactured by Toray DuPont) having a glass transition point of 230 ° C. and a copper foil were sequentially laminated on the surface of the base substrate having the conductor wiring. Subsequently, the base substrate and the thermoplastic polyimide film, and the thermoplastic polyimide film and the copper foil were bonded to each other by a heat press under conditions of a temperature of 360 ° C., a press pressure of 3.9 MPa (40 kg / cm ² ), and a processing time of 5 minutes. did. Thereby, a printed wiring board having the structure shown in FIG. 1 was obtained.

[Example 7]
A base substrate was obtained in the same manner as in Example 1. The conductor wiring on the base substrate was subjected to the same plurality of plating treatments and chromate treatments as in Example 1.

Subsequently, on the surface of the base substrate where the conductor wiring is present, a thermoplastic polyimide film having a glass transition point of 300 ° C. (manufactured by Toray DuPont, product name Kapton JP), a polyimide layer, and both surfaces of this layer, respectively. A multilayer film (manufactured by Kaneka, trade name Pixio) including two layers made of thermoplastic polyimide and a copper foil were laminated in this order. Subsequently, the base substrate and the thermoplastic polyimide film, the thermoplastic polyimide film and the multilayer film, and the multilayer film were heated and pressed under conditions of a temperature of 400 ° C., a press pressure of 3.9 MPa (40 kg / cm ² ), and a treatment time of 5 minutes. Each copper foil was bonded. As a result, a printed wiring board having the structure shown in FIG. 2 was obtained.

[Example 8]
A base substrate was obtained in the same manner as in Example 1. The conductor wiring on the base substrate was subjected to the same plurality of plating treatments and chromate treatments as in Example 1.

Subsequently, a thermoplastic polyimide film having a glass transition point of 150 ° C. (manufactured by Toray Industries, Inc.), a polyimide layer, and two layers on each side of this layer on the surface of the base substrate where the conductor wiring is present. A multilayer film (manufactured by Kaneka, trade name Pixio) having a layer made of thermoplastic polyimide and a copper foil were laminated in this order. Subsequently, the base substrate and the thermoplastic polyimide film, the thermoplastic polyimide film and the multilayer film, and the multilayer film were heated and pressed under conditions of a temperature of 250 ° C., a press pressure of 3.9 MPa (40 kg / cm ² ), and a treatment time of 5 minutes. Each copper foil was bonded. As a result, a printed wiring board having the structure shown in FIG. 2 was obtained.

[Example 9]
A base substrate was obtained in the same manner as in Example 1. The conductor wiring on the base substrate was subjected to the same plurality of plating treatments and chromate treatments as in Example 1.

  On a surface of a polyimide film (product name: Kapton EN, manufactured by Toray DuPont), a layer having a thickness of 25 μm made of thermoplastic polyimide (a thermoplastic polyimide similar to the product name Kapton KJ, manufactured by Toray DuPont) having a glass transition point of 230 ° C. On the other surface, a layer having a thickness of 2 μm made of thermoplastic polyimide having a glass transition point of 230 ° C. (a thermoplastic polyimide similar to Kapton KJ, manufactured by Toray DuPont) was formed. This obtained the multilayer film.

Subsequently, a layer having a thickness of 25 μm in the multilayer film was overlaid on the surface of the base substrate having the conductor wiring, and a copper foil was overlaid on the multilayer film. Subsequently, the base substrate and the multilayer film, and the multilayer film and the copper foil were bonded to each other by a heating press under conditions of a temperature of 360 ° C., a press pressure of 3.9 MPa (40 kg / cm ² ), and a treatment time of 5 minutes. As a result, a printed wiring board having the structure shown in FIG. 2 was obtained.

[Comparative Example 1]
A double-sided copper clad laminate provided with an insulating layer made of polyimide was prepared. Conductive wiring was formed by performing an etching process on one of the two copper foils in the double-sided copper-clad laminate. As a result, a base substrate was obtained. The conductor wiring on the base substrate was subjected to the same plurality of plating treatments and chromate treatments as in Example 1.

Subsequently, a thermoplastic polyimide film (product name: Kapton KJ, manufactured by Toray DuPont) having a glass transition point of 230 ° C. and a copper foil were sequentially laminated on the surface of the base substrate having the conductor wiring. Subsequently, the base substrate and the thermoplastic polyimide film, and the thermoplastic polyimide film and the copper foil were bonded to each other by a heat press under conditions of a temperature of 360 ° C., a press pressure of 3.9 MPa (40 kg / cm ² ), and a processing time of 5 minutes. A printed wiring board was obtained.

[Curve evaluation]
Samples having a size of 70 mm × 240 mm were cut out from the printed wiring boards obtained in Examples 1 to 9 and Comparative Example 1. The copper foil on the surface of this sample was completely removed by etching, and then heated in an oven at 200 ° C. for 1 hour. Subsequently, each sample was placed on a flat surface with the layer derived from the thermoplastic polyimide film facing upward. In this state, when the sample is warped so as to protrude downward, if the maximum value of the gap between the flat surface and the sample is n, “−n” is regarded as the warp amount. When the sample warps so as to be convex upward, if the maximum value of the gap between the flat surface and the sample is n, “+ n” is regarded as the warp amount. The measurement was performed using a taper gauge.

  As a result, if the amount of warpage was within the range of −40 mm to +40 mm, it was evaluated as “A”, and when out of this range, it was evaluated as “B”.

[Evaluation of fillability between lines]
The copper foil on the surface of the printed wiring board obtained in each example and comparative example was all removed by etching. Subsequently, the layer derived from the thermoplastic polyimide film was visually observed to confirm the presence or absence of voids between the conductor wirings derived from the base substrate. As a result, a case where no void was recognized and the space between the lines was sufficiently filled with resin was evaluated as “A”, and a case where void was observed and the resin between the lines was insufficiently filled was evaluated as “B”. . The residual copper ratio of the conductor wiring (that is, the residual ratio of the copper foil that is the material of the conductor wiring) is 70%.

[Solder heat resistance evaluation]
The solder heat resistance test of the printed wiring board obtained in each Example and Comparative Example was performed under the conditions of a heating temperature of 260 ° C. and a heating time of 30 seconds by a method according to JIS C6481. As a result, the case where no blistering occurred on the printed wiring board was evaluated as “A”, and the case where blistering occurred was evaluated as “B”.

11 Insulating layer (first insulating layer)
12 Second insulating layer 21 Conductor wiring (first conductor wiring)
22 Second conductor wiring 31 Wiring board part (first wiring board part)
310 Base substrate (first base substrate)
32 Second Wiring Board 320 Second Base Substrate 4 Adhesive Layer 40 Resin Film 51 Core Layer (First Core Layer)
52 2nd core layer 611,612 Cover layer (1st cover layer)
62,621,622 Second cover layer 72 Metal layer (second metal layer)
720 Metal foil 81, 82 Resin layer 91, 92 Multilayer resin film

Claims (5)

A wiring board portion comprising an insulating layer and a conductor wiring on the insulating layer;
An adhesive layer on the wiring board portion and covering the conductor wiring;
The insulating layer includes a polyimide core layer and two thermoplastic polyimide cover layers respectively on both sides of the core layer,
The printed wiring board, wherein the adhesive layer is made of thermoplastic polyimide, and the conductor wiring is embedded in the adhesive layer. The printed wiring board according to claim 1, wherein a glass transition point of the adhesive layer is in a range of 150 to 300 ° C. The printed wiring board according to claim 1, wherein at least one of a metal plating process and a chromate process is performed on the conductor wiring. The metal plating treatment is performed on the conductor wiring, and the metal plating treatment includes at least one of a zinc plating treatment, a tin plating treatment, a nickel plating treatment, a molybdenum plating treatment, and a cobalt plating treatment. Printed wiring board. The printed wiring board according to any one of claims 1 to 4, wherein the adhesive layer is for bonding other members constituting the printed wiring board to the wiring board portion.