The present application is based upon and claims the benefit of priority to Japanese Patent Application No. 2018-097836, filed May 22, 2018, the entire contents of which are incorporated herein by reference.
The present invention relates to a printed wiring board having a wiring covered by a magnetic resin, and relates to a method for manufacturing the printed wiring board.
Japanese Patent Laid-Open Publication No. 2014-32978 describes an inductor component in which a magnetic layer and a resin layer are provided on each of multiple layers of inductor patterns. The entire contents of this publication are incorporated herein by reference.
According to one aspect of the present invention, a printed wiring board includes a first conductor layer, a first resin insulating layer formed on the first conductor layer, a second conductor layer formed on the first resin insulating layer, a second resin insulating layer formed on the second conductor layer, a third conductor layer formed-on the second resin insulating layer, a first via conductor formed in the first resin insulating layer such that the first via conductor is penetrating through the first resin insulating layer and connecting the first conductor layer and the second conductor layer, a second via conductor formed in the second resin insulating layer such that the second via conductor is penetrating through the second resin insulating layer and connecting the second conductor layer and the third conductor layer, and a magnetic resin portion formed in an opening of the first resin insulating layer such that the magnetic resin portion is covering part of the first conductor layer and that the second conductor layer is not formed in a region of the first resin insulating layer where the magnetic resin portion is formed.
According to another aspect of the present invention, a method for manufacturing a printed wiring board includes forming a first conductor layer on a support plate, forming a first resin insulating layer on the first conductor layer, forming a first via conductor in the first resin insulating layer and a via land of the first via conductor on the first resin insulating layer, forming a through hole in the first resin insulating layer such that the through hole exposes part of the first conductor layer, and filling a magnetic resin into the through hole formed in the first resin insulating layer such that the magnetic resin portion covering the part of the first conductor layer is formed in the first resin insulating layer.
According to yet another aspect of the present invention, a method for manufacturing a printed wiring board includes forming a first conductor layer on a support plate, forming a magnetic resin portion on the first conductor layer, forming a first resin insulating layer on the support plate such that the first resin insulating layer covers the magnetic resin portion, forming a first via conductor in the first resin insulating layer and a via land of the first via conductor on the first resin insulating layer, forming a second resin insulating layer on the first resin insulating layer such that the second resin insulating layer covers the via land of the first via conductor, and forming a second via conductor in the second resin insulating layer and a via land of the second via conductor on the second resin insulating layer such that the second via conductor connects to the via land of the first via conductor.
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
Embodiments will now be described with reference to the accompanying drawings, wherein like reference numerals designate corresponding or identical elements throughout the various drawings.
The printed wiring board 10 has a first surface (F) and a second surface (S) on an opposite side with respect to the first surface (F), and has a lowermost first resin insulating layer (50A), a first conductor layer (40A) formed on the second surface (S) side of the first resin insulating layer, a second conductor layer (40B) formed on the first surface (F) side of the first resin insulating layer, and first via conductors (60A) that penetrate the first resin insulating layer (50A) and connect the first conductor layer (40A) and the second conductor layer (40B) to each other. A through hole 52 is provided in the first resin insulating layer (50A), and a magnetic resin 38 is filled in the through hole 52. A part of the magnetic resin 38 overflows from the through hole 52 to form a flange part (38a). An inductor pattern (40L) included in the first conductor layer (40A) is covered by the magnetic resin 38 filled in the through hole 52. That is, a side surface (40s) and an upper surface (40u) of the inductor pattern (40L) are embedded in the magnetic resin 38, and a lower surface (40b) of the inductor pattern (40L) is exposed from the magnetic resin 38. Similarly, side surfaces (40s) and upper surfaces (40u) of other parts of the first conductor layer (40A) are embedded in the first resin insulating layer (50A), and lower surfaces (40b) of the other parts of the first conductor layer (40A) are exposed from the first resin insulating layer (50A). The second conductor layer (40B) includes via lands (40BV) of the first via conductors (60A). The second conductor layer is not formed in a region directly above the magnetic resin 38.
A second resin insulating layer (50B) is provided on the first resin insulating layer (50A) and the second conductor layer (40B), and a third conductor layer (40C) is provided on the second resin insulating layer (50B). The second conductor layer (40B) and the third conductor layer (40C) are connected to each other by second via conductors (60B) that penetrate the second resin insulating layer (50B). The third conductor layer (40C) includes via lands (40CV) of the second via conductors (60B), and a conductor circuit (40CL). The conductor circuit (40CL) is also formed in a region directly above the magnetic resin 38.
A third resin insulating layer (50C) is provided on the second resin insulating layer (50B) and the third conductor layer (40C), and a fourth conductor layer (40D) is provided on the third resin insulating layer (50C). The third conductor layer (40C) and the fourth conductor layer (40D) are connected to each other by third via conductors (60C) that penetrate the third resin insulating layer (50C).
A fourth resin insulating layer (50D) is provided on the third resin insulating layer (50C) and the fourth conductor layer (40D), and a fifth conductor layer (40E) is provided on the fourth resin insulating layer (50D). The fourth conductor layer (40D) and the fifth conductor layer (40E) are connected to each other by fourth via conductors (60D) that penetrate the fourth resin insulating layer (50D).
A fifth resin insulating layer (50E) is provided on the fourth resin insulating layer (50D) and the fifth conductor layer (40E), and a sixth conductor layer (40F) is provided on the fifth resin insulating layer (50E). The fifth conductor layer (40E) and the sixth conductor layer (40F) are connected to each other by fifth via conductors (60E) that penetrate the fifth resin insulating layer (50E).
A sixth resin insulating layer (50F) is provided on the fifth resin insulating layer (50E) and the sixth conductor layer (40F), and a seventh conductor layer (40G) is provided on the sixth resin insulating layer (50F). The sixth conductor layer (40F) and the seventh conductor layer (40G) are connected to each other by sixth via conductors (60F) that penetrate the sixth resin insulating layer (50F).
A seventh resin insulating layer (50G) is provided on the sixth resin insulating layer (50F) and the seventh conductor layer (40G), and an eighth conductor layer (40H) is provided on the seventh resin insulating layer (50G). The seventh conductor layer (40G) and the eighth conductor layer (40H) are connected to each other by seventh via conductors (60G) that penetrate the seventh resin insulating layer (50G).
A first solder resist layer (70F) having openings (72F) is formed on the seventh resin insulating layer (50G) and the eighth conductor layer (40H). A corrosion resistant layer (74F) formed of, for example, a Ni/Pd/Au film is formed in the openings (72F) of the first solder resist layer (70F). Solder bumps (76F) are formed on the corrosion resistant layer (74F).
A second solder resist layer (70S) having openings (72S) is formed on the second surface (S) of the first resin insulating layer (50A) and the lower surface (40b) of the first conductor layer (40A). The lower surface (40b) of the first conductor layer (40A) exposed from the openings (72S) forms pads (73S) for connecting to an external substrate. A corrosion resistant layer (74S) formed of, for example, a Ni/Pd/Au film is formed on the pads (73S). As illustrated in
According to the printed wiring board 10 of the first embodiment, the second conductor layer (40B) is not formed in a region directly above the magnetic resin 38. Therefore, an insulation distance between the magnetic resin 38 and the second conductor layer (40B) is not a problem. Therefore, a thickness (h) of the magnetic resin 38 can be increased, and a high inductance can be obtained. Further, the first conductor layer (40A) and the third conductor layer (40C) as a conductor layer above the first conductor layer are connected to each other by the first via conductors (60A) and the second via conductors (60B). Therefore, as compared to forming a single via conductor that penetrates the first resin insulating layer (50A) and the second resin insulating layer (50B), heights of the first via conductors (60A) and the second via conductors (60B) can be reduced and connection reliability can be improved.
A method for manufacturing the printed wiring board of the first embodiment is illustrated in
A copper-clad laminated plate (support plate) 20 formed by laminating a copper foil 22 on a resin substrate 18, and a copper foil 24 are prepared. The copper foil 24 is bonded to the copper-clad laminated plate 20, and the first conductor layer (40A) formed of copper plating is formed on the copper foil 24. The first conductor layer (40A) includes the inductor pattern (40L). The first resin insulating layer (50A) is formed on the copper foil 24 and the first conductor layer (40A) (
The through hole 52 exposing the inductor pattern (40L) is formed in the first resin insulating layer (50A) using laser so as to penetrate the first resin insulating layer (50A) (
The second resin insulating layer (50B) is formed on the first resin insulating layer (50A) and on the second conductor layer (40B) and the magnetic resin 38 (
The processes of
The copper-clad laminated plate 20 in which the copper foil 22 is laminated is separated from the intermediate 110, and the copper foil 24 is removed by etching (
According to the method for manufacturing the printed wiring board of the first embodiment, the through hole 52 exposing a part of the first conductor layer (40A) covered by a magnetic resin is formed in the first resin insulating layer (50A), and the magnetic resin 38 is filled in the through hole 52. That is, the magnetic resin 38 of the thickness of the first resin insulating layer (50A) can be coated on the first conductor layer (40A). Further, the first conductor layer (40A) and the third conductor layer (40C) as a conductor layer above the first conductor layer are connected to each other by the first via conductors (60A) and the second via conductors (60B). Therefore, heights of the first via conductors (60A) and the second via conductors (60B) can be reduced, and connection reliability can be improved while a plating time is shortened. The magnetic resin 38 is mounted in advance on the highly rigid copper-clad laminated plate 20 by printing or the like, and the second resin insulating layer (50B) is coated on the magnetic resin 38. Therefore, adhesion between the magnetic resin 38 and the second resin insulating layer (50B) can be improved. Further, in the first resin insulating layer, the through hole 52 is formed using laser. Therefore, positional accuracy of the magnetic resin 38 can be improved.
A method for manufacturing a printed wiring board according to a first modified embodiment of the first embodiment is illustrated in
A copper-clad laminated plate (support plate) 20 formed by laminating a copper foil 22 on a resin substrate 18, and a copper foil 24 are prepared. The copper foil 24 is bonded to the copper-clad laminated plate 20, and the first conductor layer (40A) formed of copper plating is formed on the copper foil 24. The first conductor layer (40A) includes the inductor pattern (40L). The first resin insulating layer (50A) is formed on the copper foil 24 and the first conductor layer (40A) (
The via openings 54 reaching the first conductor layer (40A) for forming via conductors are formed in the first resin insulating layer (50A) using laser (
The through hole 52 exposing the inductor pattern (40L) is formed in the first resin insulating layer (50A) using laser so as to penetrate the first resin insulating layer (50A) (
In the printed wiring board of the second modified embodiment of the first embodiment, an eighth resin insulating layer (third resin insulating layer) (50Z) is formed on the first resin insulating layer (50A), and the magnetic resin 38 is filled in a through hole 52 penetrating the first resin insulating layer (50A) and the eighth resin insulating layer (50Z). Then, second via conductors (60B) penetrating the eighth resin insulating layer (50Z) and the second resin insulating layer (50B) are formed.
A method for manufacturing a printed wiring board according to the second modified embodiment of the first embodiment is illustrated in
A copper-clad laminated plate (support plate) 20 formed by laminating a copper foil 22 on a resin substrate 18, and a copper foil 24 are prepared. The copper foil 24 is bonded to the copper-clad laminated plate 20, and the first conductor layer (40A) formed of copper plating is formed on the copper foil 24. The first conductor layer (40A) includes the inductor pattern (40L). The first resin insulating layer (50A) is formed on the copper foil 24 and the first conductor layer (40A) (
The via openings 54 reaching the first conductor layer (40A) for forming via conductors are formed in the first resin insulating layer (50A) using laser (
The eighth resin insulating layer (third resin insulating layer) (50Z) is formed on the first resin insulating layer (50A) and the second conductor layer (40B) (
The second resin insulating layer (50B) is formed on the eighth resin insulating layer (50Z) and on the second conductor layer (40B) and the magnetic resin 38 (
Subsequent processes are the same as those of the manufacturing method of the first embodiment after
In the second embodiment, the magnetic resin 38 is filled in a recess 48 that has a trapezoidal cross-sectional shape and does not penetrate the first resin insulating layer (50A). The second resin insulating layer (50B) is formed on the magnetic resin 38 via the first resin insulating layer (50A).
A method for manufacturing the printed wiring board of the second embodiment is illustrated in
A copper-clad laminated plate (support plate) 20 formed by laminating a copper foil 22 on a resin substrate 18, and a copper foil 24 are prepared. The copper foil 24 is bonded to the copper-clad laminated plate 20, and the first conductor layer (40A) formed of copper plating is formed on the copper foil 24. The first conductor layer (40A) includes the inductor pattern (40L). The magnetic resin 38 is formed on the inductor pattern (40L) (
Via openings 54 reaching the first conductor layer (40A) for forming via conductors are formed in the first resin insulating layer (50A) using laser (
The second resin insulating layer (50B) is formed on the first resin insulating layer (50A) and on the second conductor layer (40B) (
According to the method for manufacturing the printed wiring board of the second embodiment, the magnetic resin 38 is mounted in advance on the highly rigid copper-clad laminated plate 20 by printing or the like, and the first resin insulating layer (50A) is coated on the magnetic resin 38. Therefore, adhesion between the magnetic resin 38 and the first resin insulating layer (50A) can be improved. Further, the first conductor layer (40A) and the third conductor layer (40C) as a conductor layer above the first conductor layer are connected to each other by the first via conductors (60A) and the second via conductors (60B). Therefore, heights of the first via conductors (60A) and the second via conductors (60B) can be reduced, and connection reliability can be improved while a plating time is shortened. Further, the thickness of the magnetic resin 38 can be set independent of the thickness of the first resin insulating layer (50A).
In Japanese Patent Laid-Open Publication No. 2014-32978, since an upper-layer inductor pattern is superimposed on an inductor pattern, a thickness of a magnetic layer provided on an inductor pattern is limited.
A printed wiring board according to an embodiment of the present invention includes: a first conductor layer as a lowermost layer; a second conductor layer above the first conductor layer; a third conductor layer above the second conductor layer; a first resin insulating layer between the first conductor layer and the second conductor layer; a second resin insulating layer between the second conductor layer and the third conductor layer; a first via conductor that penetrates the first resin insulating layer and connects the first conductor layer and the second conductor layer to each other; a second via conductor that penetrates the second resin insulating layer and connects the second conductor layer and the third conductor layer; and a magnetic resin that is provided in a lower side opening of the first resin insulating layer and covers a part of the first conductor layer. The second conductor layer is not formed in a region where the magnetic resin is provided.
A method for manufacturing a printed wiring board according to an embodiment of the present invention includes: forming a first conductor layer on a support plate; forming a first resin insulating layer on the support plate and the first conductor layer; forming, in the first resin insulating layer, a through hole that exposes a part of the first conductor layer, the part being to be covered by a magnetic resin; forming, in the first resin insulating layer, an opening for forming a via conductor; forming a first via conductor in the opening and forming a via land of the first via conductor on the first resin insulating layer; filling the through hole with a magnetic resin; forming a second resin insulating layer on the first resin insulating layer and the magnetic resin; and forming a second via conductor that penetrates the second resin insulating layer and reaches the via land, and forming a third conductor layer on the second resin insulating layer.
A method for manufacturing a printed wiring board according to another embodiment of the preset invention includes: forming a first conductor layer on a support plate; forming a magnetic resin on the first conductor layer; forming a first resin insulating layer on the magnetic resin and the support plate; forming, in the first resin insulating layer, an opening for forming a via conductor; forming a first via conductor in the opening and forming a via land of the first via conductor on the first resin insulating layer; forming a second resin insulating layer on the first resin insulating layer; and forming a second via conductor that penetrates the second resin insulating layer and reaches the via land, and forming a third conductor layer on the second resin insulating layer.
In a printed wiring board according to an embodiment of the present invention, the second conductor layer is not formed in a region where the magnetic resin is provided. Therefore, an insulation distance between the magnetic resin and the second conductor layer is not a problem. Therefore, a thickness of the magnetic resin can be increased, and a high inductance can be obtained. Further, the first conductor layer and the third conductor layer as a conductor layer above the first conductor layer are connected to each other by the first via conductor and the second via conductor. Therefore, heights of the first via conductor and the second via conductor can be reduced, and connection reliability can be improved.
In a method for manufacturing a printed wiring board according to an embodiment of the present invention, the through hole exposing a part of the first conductor layer covered by the magnetic resin is formed in the first resin insulating layer, and the magnetic resin is filled in the through hole. That is, the magnetic resin of a thickness of the first resin insulating layer can be coated on the first conductor layer. Therefore, a high inductance can be obtained. Further, the first conductor layer and the third conductor layer as a conductor layer above the first conductor layer are connected to each other by the first via conductor and the second via conductor. Therefore, the heights of the first via conductor and the second via conductor can be reduced, and, connection reliability can be improved while a plating time is shortened. The magnetic resin is mounted in advance on the highly rigid support plate by printing or the like, and the second resin insulating layer is coated on the magnetic resin. Therefore, adhesion between the magnetic resin and the second resin insulating layer can be improved.
In a method for manufacturing a printed wiring board according to another embodiment of the present invention, the first resin insulating layer is provided on the magnetic resin, and the second resin insulating layer is further provided. Different from providing the second resin insulating layer on the magnetic resin, the second resin insulating layer is provided on the first resin insulating layer, and adhesion is high. Therefore, reliability of the first resin insulating layer and the second resin insulating layer is high. The magnetic resin is mounted in advance on the highly rigid support plate by printing or the like, and the first resin insulating layer is coated on the magnetic resin. Therefore, adhesion between the magnetic resin and the first resin insulating layer can be improved. Further, the first conductor layer and the third conductor layer as a conductor layer above the first conductor layer are connected to each other by the first via conductor and the second via conductor. Therefore, the heights of the first via conductor and the second via conductor can be reduced, and connection reliability can be improved while a plating time is shortened.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
Number | Date | Country | Kind |
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2018-097836 | May 2018 | JP | national |