JPWO2013137044A1 - Inductor-embedded substrate manufacturing method, inductor-embedded substrate, and power supply module using the same - Google Patents

Abstract

Provided is a method for manufacturing a substrate with a built-in inductor, which can efficiently manufacture a substrate with a built-in inductor by forming an inductor built into the substrate together with a manufacturing process of manufacturing the substrate. A step of forming a pattern of a plurality of strip-shaped first coil wirings 7 on the surface of the core substrate 4, and mounting the magnetic body 5 in a region other than at least the end portion 11 in the pattern of the formed strip-shaped first coil wirings 7. A step, a step of embedding the magnetic body 5 with a resin, a step of forming a via 6 for connecting the end 11 of the strip-shaped first coil wiring 7 and the second coil wiring 8 of the upper layer, and the formed via A plurality of strip-shaped second coil wirings 8 are formed so as to be connected in a coil shape via the first coil wiring 7 and via 6 to the upper metal thin film formed in the plating process. Including the step of. Figure 1

Description

  The present invention relates to a substrate in which an inductor is built, a manufacturing method thereof, and a power supply module using the same.

  In recent years, with the rapid miniaturization of electronic devices, the elements used in the electronic devices are also required to be miniaturized. An example of an element used in an electronic device is an inductor. The inductor constitutes a resonance circuit and a filter circuit, and particularly when used in a power supply module or the like, an inductor having a large allowable current is required, so that there is a problem that the element itself becomes large.

  In relation to such problems, for example, techniques disclosed in Patent Documents 1 to 3 are disclosed for inductors. The techniques shown in Patent Documents 1 to 3 are multi-layer boards with built-in inductors, and a plurality of wiring board layers including a signal wiring layer, a ground layer, a power supply layer, and the like arranged between the front and back surfaces or the core layer. And a single layer or a plurality of core layers with a built-in inductor. The inductor is a multi-layer substrate with a built-in inductor, which is a helical inductor having a structure in which a conductor is wound around a thin magnetic material. It is disclosed that an inductor element is manufactured by forming a coil so that a laminated magnetic body is wound with a wiring pattern of a metal thin film and a through hole.

  In addition, the following three types of methods are disclosed as specific manufacturing methods for incorporating an inductor inside a multilayer substrate. The first is a method of using a through-hole in a position where an electronic component is placed in advance, and the second is a method in which a semi-through hole is opened in a position where a component is placed in advance, the component is placed, and crimped. The third method is to connect the component to the lower substrate, place the substrate on the lower substrate, and press the substrate as it is. In both techniques, an inductor built-in board is manufactured by embedding an inductor manufactured as a component by embedding it in the board manufacturing process.

Japanese Patent Application Laid-Open No. 2004-319885 JP 2004-363162 A JP-A-2005-101175

  However, in the techniques described in the above patent documents, the manufacturing process is deteriorated because the process of manufacturing the inductor and the process of manufacturing the substrate are separate and independent processes. In addition, since the process of manufacturing the inductor and the process of manufacturing the substrate are independent, there is a possibility that the characteristics of the wiring such as the resistance and capacitance of the board will differ from the characteristics of the wiring such as the resistance of the inductor and the capacity. However, a defect occurs in the connection part of the inductor and the accuracy of the substrate is deteriorated.

  The present invention makes it possible to manufacture an inductor-embedded substrate very efficiently by making an inductor incorporated in the substrate in the manufacturing process of manufacturing the substrate, and also provides high precision with common wiring characteristics. A substrate with a built-in inductor and a method for manufacturing the same are provided.

  A method for manufacturing a substrate with a built-in inductor according to the present invention includes a first wiring step for forming a plurality of strip-shaped wiring patterns on a surface of a core substrate, and excluding at least an end portion of the strip-shaped wiring pattern formed in the first wiring step. A via hole for connecting a magnetic body mounting step for mounting a magnetic body in a region, an embedding step of embedding the magnetic body with an insulating material, and an end portion of the strip-shaped wiring pattern and a wiring pattern formed in an upper layer A via hole forming step, a filling step for filling the via hole formed in the via hole forming step with a conductive material, and a via formed in the filling step, and connected to the via in the stacking direction of the substrate. A second wiring step of forming a plurality of strip-like wiring patterns on the upper metal thin film formed in the filling step so that the wiring is formed as a coil magnetized in a vertical direction.

  As described above, in the inductor-embedded substrate manufacturing method according to the present invention, an inductor having a magnetic material as a core is formed in a normal substrate manufacturing process, so that a substrate having an inductor embedded therein is manufactured very efficiently. There is an effect that can be done.

  Also, the wiring as the inductor coil is created in the board manufacturing process, so that the electrical characteristics (resistance, capacitance, etc.) of the wiring of the current flowing in the inductor coil and the wiring of the board are made common. Therefore, it is possible to manufacture a highly accurate substrate with a built-in inductor.

  In the method for manufacturing a substrate with a built-in inductor according to the present invention, the band-shaped wiring pattern and the via are formed by the same plating process.

  As described above, in the method for manufacturing an inductor-embedded substrate according to the present invention, wiring as a coil of the inductor is formed by a similar plating process in the substrate manufacturing process. The electrical characteristics (such as resistance and capacitance) can be shared with the other wiring, and it is possible to produce a highly accurate substrate with a built-in inductor.

  The substrate with a built-in inductor according to the present invention includes a plurality of strip-shaped first wiring patterns formed on the surface of a core substrate, a magnetic body attached to a region excluding at least an end of the first wiring pattern, and the first An insulating material for molding the wiring pattern and the magnetic body, and a plurality of strip-shaped second wiring patterns formed on the upper surface of the insulating material, wherein the first wiring pattern and the second wiring pattern are The wirings are connected by vias so that the wiring is formed as a coil magnetized in a direction perpendicular to the stacking direction of the substrates.

  As described above, in the substrate with a built-in inductor according to the present invention, a plurality of strip-shaped first wiring patterns formed on the surface of the core substrate and a magnetic body attached to a region excluding at least an end of the first wiring pattern. And an insulating material for molding the first wiring pattern and the magnetic material, and a plurality of strip-shaped second wiring patterns formed on the upper surface of the insulating material, wherein the first wiring pattern and the second wiring Since the patterns are connected by vias so that the wiring is formed as a coil that is magnetized in a direction perpendicular to the stacking direction of the substrate, the electric current between the wiring of the current flowing in the inductor coil and the wiring of the substrate Characteristic (resistor, capacitance, etc.) can be made common, and an extremely high precision substrate with a built-in inductor can be realized.

  In the inductor-embedded substrate according to the present invention, a plurality of the inductors are arranged in parallel, and the coil wirings of the inductors are continuously connected in series, and the magnetization directions of the adjacent inductors are opposite to each other. It is the direction.

  As described above, the inductor-embedded substrate according to the present invention includes a plurality of the inductors arranged in parallel, and the coil wirings in the inductors are continuously connected in series, and the magnetization directions of the adjacent inductors However, since the directions are opposite to each other, the inductance is increased, and the influence of the magnetic field to the outside is greatly reduced by the interlinkage magnetic flux between adjacent inductors, thereby realizing a highly accurate substrate with a built-in inductor. There is an effect that can be done.

  In the inductor-embedded substrate according to the present invention, the two magnetic bodies are arranged in parallel, a plurality of first vias formed along the outer side surface of each magnetic body, and the inner side surface of the magnetic body A second via common to each magnetic body formed along the first wiring pattern, the second wiring pattern, the first via, and the second via. The first wiring pattern, the second wiring pattern, the first via, and the second via are formed so as to be alternately wound around the body every one or a plurality of turns.

  Thus, in the inductor-embedded substrate according to the present invention, the two magnetic bodies are arranged in parallel, a plurality of first vias formed along the outer side surface of each magnetic body, and the magnetic body A second via common to each of the magnetic bodies formed along the inner side surface, and the coil formed by the first wiring pattern, the second wiring pattern, the first via, and the second via. The first wiring pattern, the second wiring pattern, the first via, and the second via are formed so as to be alternately wound around each magnetic body every one or a plurality of turns. The second via formed along the side surface, that is, between the two magnetic bodies can be used in common, and the element can be miniaturized by reducing the area occupied by the inductor. .

  In the inductor-embedded substrate according to the present invention, the magnetic body has a closed loop shape, and the first wiring pattern, the second wiring pattern, and the via are formed as a coil around which the magnetic body is wound.

  As described above, in the substrate with a built-in inductor according to the present invention, since the magnetic body is in a closed loop shape, there is an effect that the magnetic flux is stably linked.

  A power supply module according to the present invention is a power supply module using the substrate with a built-in inductor, wherein a DC / DC converter connected in series with the inductor is mounted on the inductor, and a subsequent stage portion of the inductor. The output unit and the capacitor are connected in parallel, and the DC / DC converter and the capacitor are arranged to face each other with the magnetic body of the inductor interposed therebetween.

  As described above, the power supply module according to the present invention has an effect that a highly accurate power supply module can be realized by absorbing unnecessary electromagnetic waves from the DC / DC converter by the magnetic material constituting the inductor. In other words, the DC / DC converter and the capacitor are arranged opposite to each other with the magnetic body of the inductor interposed therebetween, so that electromagnetic waves from the DC / DC converter to the capacitor are absorbed by the magnetic body, and the power supply module is made highly accurate. It becomes possible to function.

  In addition, since the DC / DC converter and the capacitor are disposed to face each other with the magnetic body of the inductor interposed therebetween, the area when viewed in plan can be reduced, and the power supply module can be miniaturized. There is an effect.

  The method for manufacturing a substrate with a built-in inductor according to the present invention includes a magnetic material embedding step of embedding a magnetic material in a core substrate, and a wiring layer forming step of forming a wiring layer on the front and back surfaces of the core base material embedded with the magnetic material. A via hole forming step for connecting the wiring layers on the front surface and the back surface, a filling step for filling the via hole formed in the via hole forming step with a conductive material, and the filling step The via formed in the above, and the wiring layer formed on the surface of the core base material and the wiring layer formed on the back surface thereof become a coil magnetized in a direction perpendicular to the stacking direction of the substrate. And a wiring process for forming a wiring pattern of the wiring layers on the front surface and the back surface.

  The inductor-embedded substrate manufacturing method according to the present invention includes a second wiring layer forming step in which a wiring layer is formed again on the front surface and the back surface of the wiring pattern formed by the wiring step, the second wiring layer forming step, In addition, the via hole forming step, the filling step, and the wiring step are repeated one or more times to form the coil with a plurality of turns.

  The method for manufacturing a substrate with a built-in inductor according to the present invention includes a first wiring step of forming a plurality of strip-shaped wiring patterns on the front surface and the back surface of the core substrate, and a front surface and a back surface of the core substrate formed in the first wiring step. A magnetic body mounting step of mounting a magnetic body in a region excluding at least an end portion of the strip-shaped wiring pattern, a burying step of embedding the magnetic body with an insulating material, an end portion of the strip-shaped wiring pattern, and each wiring pattern In the via hole forming step for forming a via hole for connecting the wiring pattern formed in the upper layer, the filling step for filling the via hole formed in the via hole forming step with a conductive material, and the filling step The wiring is formed so that a wiring is formed as a coil that is connected to the formed via and is magnetized in a direction perpendicular to the stacking direction of the substrate on each of the front surface and the back surface across the core substrate. The upper layer of the metal thin film formed in step is intended to include a second wiring step of forming a strip of a plurality of wiring patterns.

  As described above, in the inductor-embedded substrate manufacturing method according to the present invention, an inductor having a magnetic material as a core is formed in a normal substrate manufacturing process, so that a substrate having an inductor embedded therein is manufactured very efficiently. There is an effect that can be done. Also, the wiring as the inductor coil is created in the board manufacturing process, so that the electrical characteristics (resistance, capacitance, etc.) of the wiring of the current flowing in the inductor coil and the wiring of the board are made common. Therefore, it is possible to manufacture a highly accurate substrate with a built-in inductor.

It is the perspective view and sectional drawing of the board | substrate with a built-in inductor created with the board | substrate manufacturing method with a built-in inductor which concerns on 1st Embodiment. It is a flowchart which shows the procedure of the board | substrate manufacturing method with a built-in inductor which concerns on 1st Embodiment. It is sectional drawing in each procedure of the board | substrate manufacturing method with a built-in inductor which concerns on 1st Embodiment. It is a top view in a part of procedure of an inductor built-in substrate manufacturing method concerning a 1st embodiment. It is a 1st top view of an inductor in a power supply module concerning a 2nd embodiment. It is a 2nd top view of an inductor in a power supply module concerning a 2nd embodiment. It is a figure explaining the power supply module which concerns on 3rd Embodiment. It is the perspective view and sectional drawing of the board | substrate with a built-in inductor which concern on 4th Embodiment. It is a 1st figure which shows the cross section in each procedure of the manufacturing method of the board | substrate with a built-in inductor which concerns on 4th Embodiment. It is a 2nd figure which shows the cross section in each procedure of the manufacturing method of the board | substrate with a built-in inductor which concerns on 4th Embodiment. It is the perspective view and sectional drawing of the board | substrate with a built-in inductor which concern on 5th Embodiment. It is sectional drawing in each procedure of the manufacturing method of the board | substrate with a built-in inductor which concerns on 5th Embodiment. It is a 1st figure which shows the structure of the board | substrate with a built-in inductor which concerns on other embodiment. It is a 2nd figure which shows the structure of the board | substrate with a built-in inductor which concerns on other embodiment.

  Embodiments of the present invention will be described below. The present invention can be implemented in many different forms. Also, the same reference numerals are given to the same elements throughout the present embodiment.

(First embodiment of the present invention)
The inductor built-in substrate and the inductor built-in substrate manufacturing method according to the present embodiment will be described with reference to FIGS. 1 is a perspective view and a cross-sectional view of an inductor-embedded substrate produced by the inductor-embedded substrate manufacturing method according to the present embodiment. FIG. 2 is a flowchart showing a procedure of the inductor-embedded substrate manufacturing method according to the present embodiment. FIG. 4 is a cross-sectional view in each procedure of the inductor-embedded substrate manufacturing method according to the present embodiment, and FIG. 4 is a top view of a part of the procedure of the inductor-embedded substrate manufacturing method according to the present embodiment.

  The structure of the inductor-embedded substrate 1 according to this embodiment will be described with reference to FIG. FIG. 1A is a perspective view of a substrate 1 with a built-in inductor according to the present embodiment, and FIG. 1B is a cross-sectional view when viewed from the direction of arrow a in FIG. As shown in FIGS. 1A and 1B, an inductor-embedded substrate 1 according to this embodiment includes a core substrate 4 composed of at least a core material 3 and copper thin films 2a and 2b covering the front and back surfaces of the core material 3. The inductor 10 is formed thereon.

  The inductor 10 is a coil that winds the magnetic body 5 so as to be magnetized in a direction perpendicular to the stacking direction of the substrate (the surface direction of the core substrate 4) with the magnetic body 5 mounted on the core substrate 4. Wiring (first coil wiring 7, via 6 and second coil wiring 8). When the copper thin film 2a on the upper surface side of the core substrate 4 is a first layer, the first coil wiring 7 is formed in the first layer, and the second coil wiring 8 is a second layer that is an upper layer of the first layer. It is formed in the layer. The first coil wiring 7 and the second coil wiring 8 are electrically connected continuously via the via 6, and a current flows through the first coil wiring 7, the via 6, and the second coil wiring 8. The inductor 10 is configured by flowing a coil (spiral) around the magnetic body 5. Between the first layer and the second layer, a resin 12 (not shown in FIG. 1A) as an insulating material is filled in the same manner as a normal component-embedded substrate.

  The inductor built-in substrate 1 shown in FIG. 1 can be manufactured by the inductor built-in substrate manufacturing method according to the present embodiment. In the inductor-embedded substrate manufacturing method according to the present embodiment, the inductor 10 is formed in the substrate manufacturing process. That is, the manufacturing process of the inductor 10 and the board manufacturing process are made independent and only the inductor 10 is created in the inductor manufacturing process, and then the separately created inductor 10 is embedded in the board as a component in the board manufacturing process. Instead, by manufacturing the inductor 10 while manufacturing the substrate, the manufacturing process of the inductor-embedded substrate 1 can be simplified, and the manufacturing efficiency can be significantly improved.

  A processing procedure of the inductor-embedded substrate manufacturing method according to the present embodiment will be specifically described with reference to FIGS. First, in step S1 of FIG. 2, a core substrate 4 whose surface is coated with a copper foil as shown in FIG. 3A is prepared, and the magnetic material 5 is wound around the copper thin film 2a on the upper surface of the core substrate 4. A first coil wiring 7 corresponding to a wiring pattern under the rotating coil is formed by etching (see FIGS. 3B and 4A). Here, as shown in FIG. 4A, in order to form the wiring in the coil shape of the inductor, a plurality of strip-shaped first coil wirings 7 are formed in an oblique direction.

  Note that the wiring area of the first coil wiring 7 shown in FIG. 4 describes only the minimum wiring area, and the area other than the wiring area of the first coil wiring 7 described here is a copper thin film. 2a may be removed, the copper thin film 2a may remain, or other necessary wiring patterns may be formed. When the copper thin film 2a remains, it is necessary not to be electrically connected to the first coil wiring 7.

  When the first coil wiring 7 is formed in step S1 of FIG. 2, the magnetic body 5 is attached to the region excluding at least the end portion 11 of the first coil wiring 7 in step S2 (FIGS. 3C and 4). (See (B)). Here, as shown in FIG. 4B, the magnetic body 5 needs to be mounted in a region excluding the end portion 11 for connection with the via 6 formed in the subsequent manufacturing process.

  When the magnetic body 5 is mounted in step S2 of FIG. 2, the mounted magnetic body 5 is sealed with a resin 12 as an insulating material in step S3 (see FIG. 3D). When the magnetic body 5 is embedded in the resin 12, a via hole 6a is formed in step S4 (see FIGS. 3E and 4C). Here, as shown in FIG. 4C, via holes 6a are formed at the positions of the end portions 11 of the first coil wiring 7 and the positions connected to the wiring for inputting and outputting signals. The via hole 6a can be drilled using, for example, a laser.

  When the via hole 6a is formed in step S4 of FIG. 2, the formed via hole 6a and the second layer are filled with plating in step S5 (see FIG. 3F). In step S6, the second coil wiring 8 corresponding to the wiring pattern above the inductor 10 is formed by etching the second layer copper thin film formed in the plating process (FIGS. 3G and 4). (See (D)). Here, as shown in FIG. 4D, the second coil wiring 8 is etched between the vias 6 so that the magnetic body 5 is wound in a coil shape in a direction perpendicular to the stacking direction of the substrates. Form. As described above, in the substrate manufacturing process, the wiring (first coil wiring 7, via 6, and second wiring) for causing the magnetic body 5 to function as a coil spirally wound in a direction perpendicular to the stacking direction of the substrate. Coil wiring 8) is formed.

  In addition, when forming the 1st coil wiring 7, the via | veer 6, and the 2nd coil wiring 8, you may make it carry out by the same or a series of plating processes. By doing so, the electrical characteristics (resistance, capacity, etc.) of the first coil wiring 7, the via 6 and the second coil wiring 8 and other wiring on the substrate can be surely shared.

  Thus, in the inductor built-in substrate manufacturing method according to the present embodiment, the inductor 10 having the magnetic body 5 as a core is formed in the normal substrate manufacturing process, so that the inductor built-in substrate 1 is very efficient. Can be manufactured well.

  In addition, since the inductor 10 is formed in the manufacturing process of the substrate, the wiring of the inductor 10 (first coil wiring 7, via 6 and second coil wiring 8) formed in a coil shape and other wiring Since electrical characteristics (resistance, capacitance, etc.) can be shared, it is possible to manufacture a highly accurate substrate with a built-in inductor. In other words, when only the inductor is manufactured in a separate process and the separately manufactured inductor is embedded as a component in the board manufacturing process, the wiring between the inductor and the board needs to be connected. If there is, there will be a substrate with poor accuracy. Such a problem can be avoided by using the inductor built-in substrate manufacturing method of the present embodiment.

(Second embodiment of the present invention)
The substrate with a built-in inductor according to this embodiment will be described with reference to FIGS. FIG. 5 is a first top view of the inductor in the power supply module according to the present embodiment, and FIG. 6 is a second top view of the inductor in the power supply module according to the present embodiment. In addition, in this embodiment, the description which overlaps with each said embodiment is abbreviate | omitted.

  In the inductor-embedded substrate according to the present embodiment, a plurality of inductors 10 are connected in series, and the inductors 10 are arranged in parallel at a predetermined interval. The wires are formed so that the currents flowing in the coiled wires of the adjacent inductors 10 are in opposite directions. 5 and 6 show a case where two inductors 10 are arranged in parallel.

  As shown in FIG. 5, the coiled wires of the adjacent inductors are connected in series in series, and the wires are formed so that the magnetization directions are opposite to each other. Can be increased, and the influence of the magnetic field to the outside can be reduced by the interlinkage magnetic flux between the adjacently arranged inductors, thereby realizing a highly accurate power supply module.

  Note that the wiring pattern in FIG. 5 is merely an example, and the power supply module according to the present embodiment can be used as long as the wiring pattern in which the respective magnetization directions of the adjacent inductors 10 are reversed. Can be realized. Another example is shown in FIG.

  In the wiring pattern of FIG. 6, two magnetic bodies 5 are arranged in parallel, a plurality of first vias 6 a formed along the outer side surface of each magnetic body 5, and the inner side surface of the magnetic body 5. A second via 6b common to each magnetic body 5 formed in this manner, and a coil formed by the second coil wiring 8, the first via 6a, the first coil wiring 7, and the second via 6b The second coil wiring 8, the first via 6a, the first coil wiring 7, and the second via 6b are formed so as to be alternately wound around the magnetic body 5 every one or a plurality of turns. That is, like FIG. 5, the coil-shaped wiring is continuously connected in series, and the magnetization direction of each inductor is opposite, but the second via 6b is a common via for each inductor, The wiring of the coil wound around the magnetic body 5 is wound alternately every turn.

  With the configuration shown in FIG. 6, the inductance value can be increased similarly to the case of FIG. 5, and the influence of the external magnetic field can be reduced by the interlinkage magnetic flux between the adjacently arranged inductors. A highly accurate power supply module can be realized by reducing the number. Also, by using the second via 6b as a common via for each inductor, the area occupied by the inductor can be reduced and the element can be miniaturized.

  The inductors shown in FIGS. 5 and 6 do not necessarily have to be built in the board manufacturing process, but may be separately created as a single component and then embedded in the board. That is, an inductor can be manufactured by forming a via hole in the magnetic material itself and forming a coil-shaped wiring pattern by plating on the upper and lower surfaces. In particular, in the case of the configuration shown in FIG. 6, a plurality of first vias 6a and second vias 6b are alternately formed in the magnetic body 5, and the respective vias, the first coil wiring 7 and the second coil wiring 8 are plated. Then, the magnetic body 5 is cut so that only the row of the first vias 6a is divided (separated into a semi-cylindrical shape) by the vertical cut surface. Parts can be made.

(Third embodiment of the present invention)
A power supply module using the inductor-embedded substrate according to the present embodiment will be described with reference to FIG. FIG. 7 is a diagram for explaining an example of the power supply module according to this embodiment. FIG. 7A shows a circuit diagram of a general step-down DC / DC converter, and FIG. Sectional drawing of a power supply module is shown. In the present embodiment, descriptions overlapping with those in the first embodiment are omitted. The inductor 10 according to the present embodiment functions as a DC / DC converter choke coil that is an external component of the DC / DC converter IC.

  The power supply module 20 according to the present embodiment uses the inductor-embedded substrate 1 according to the first embodiment, and has a circuit configuration shown in FIG. That is, the switching element 17 and the inductor 10 are connected in series between the input terminal and the output terminal, the capacitor 16 is connected between the output terminal and the ground, and the connection point between the switching element 17 and the inductor 10 and the ground. The diode 18 is connected to the switching element 17, and the DC / DC converter is connected to the control terminal of the switching element 17.

  As shown in FIG. 7B, the specific structure is that a DC / DC converter 15 is mounted at a position corresponding to the upper position of the inductor 10, and the DC / DC converter 15 and the inductor 10 are connected in series. The wiring is formed as described above. In addition, a capacitor 16 connected to the inductor 10 through a via is formed in a lower layer of the inductor 10 across the core. With such a structure, the circuit in FIG. 7A is realized.

  At this time, the DC / DC converter 15 and the capacitor 16 are preferably disposed so as to face each other with the magnetic body of the inductor 10 interposed therebetween.

  Further, the capacitor 16 can be incorporated as a component, but in the case of this embodiment, a power supply module can be formed in the board manufacturing process by making it in the board manufacturing process. , Manufacturing efficiency can be improved.

  As described above, the power supply module 20 according to the present embodiment includes the DC / DC converter 15 mounted on the inductor 10, and the capacitor connected to the inductor 10 is formed by forming in the substrate manufacturing process. The module 20 manufacturing efficiency can be improved. In addition, since the DC / DC converter 15 and the capacitor 16 are disposed to face each other with the magnetic body 5 of the inductor 10 interposed therebetween, the magnetic body 5 constituting the inductor 10 eliminates unnecessary power from the DC / DC converter 15. A highly accurate power supply module can be realized by absorbing electromagnetic waves.

(Fourth embodiment of the present invention)
The substrate with a built-in inductor according to this embodiment will be described with reference to FIGS. FIG. 8 is a perspective view and a cross-sectional view of the inductor-embedded substrate according to the present embodiment, FIG. 9 is a first view illustrating a cross-section in each procedure of the method for manufacturing the inductor-embedded substrate according to the present embodiment, and FIG. It is a 2nd figure which shows the cross section in each procedure of the manufacturing method of the board | substrate with a built-in inductor which concerns on this embodiment. In addition, in this embodiment, the description which overlaps with each said embodiment is abbreviate | omitted.

  The structure of the inductor-embedded substrate 1 according to this embodiment will be described with reference to FIG. FIG. 8A is a perspective view of the inductor-embedded substrate 1 according to this embodiment, and FIG. 8B is a cross-sectional view when viewed from the direction of arrow a in FIG. 8A. In the inductor-embedded substrate 1 according to the present embodiment, the number of turns of the wiring as the coil around which the magnetic body 5 is wound is one in the inductor-embedded substrate 1 shown in FIG. 1 in the first embodiment. Thus, the wiring and the via are formed so as to be wound a plurality of times (twice in FIG. 8). That is, by increasing the number of turns of the coil, an inductance having a larger value can be obtained as compared with the inductor-embedded substrate 1 according to the first embodiment.

  Next, an example of the method for manufacturing the inductor-embedded substrate 1 according to the present embodiment will be described with reference to FIGS. First, a core material with copper foil on both sides is prepared (FIG. 9A), and the entire surface of the copper foil is removed by etching (FIG. 9B). A cavity for housing the magnetic body 5 and a hole for positioning are made in the core material (FIG. 9C). An interlayer insulating material with a copper foil is attached to the back side (FIG. 9D), and the magnetic body 5 is put into the cavity (FIG. 9E). The surface side is embedded with an interlayer insulating material with a copper foil (FIG. 9F). Wiring as a coil is formed by patterning on the back side, and patterning is performed leaving only a pattern for drilling X-rays on the front side (FIG. 9G). In order to form an interlayer insulating material with copper foil on both sides (FIG. 9H), and to form through holes between the second layer and the third layer, and between the second layer and the fourth layer. Is drilled (FIG. 9I). At this time, positioning uses a hole in the outer frame.

  Subsequently, through-hole plating is performed after desmearing (FIG. 10A). A positioning hole is made by X-rays using the wiring pattern on the front surface side (FIG. 10B). Wiring as a coil is formed by patterning on the front surface side (second layer) and the back surface side (fourth layer), and a pattern for drilling X-rays is formed (FIG. 10C). At this time, the positioning uses the X-ray hole drilled in FIG. In order to form an interlayer insulating material with copper foil on both sides (FIG. 10D), and to form through holes between the first layer and the fourth layer and between the first layer and the fifth layer. Is drilled (FIG. 10E). At this time, positioning uses a hole in the outer frame. Through-hole plating is performed after desmearing (FIG. 10F). A positioning hole is made by X-ray using the wiring pattern of FIG. 10C (FIG. 10G). Wirings as coils are formed by patterning on the front surface side (first layer) and the back surface side (fifth layer) (FIG. 10H). At this time, the positioning uses the X-ray hole drilled in FIG. Patterning is performed with a solder resist (FIG. 10I). At this time, the positioning uses the X-ray hole drilled in FIG. Finally, electroless Ni / Au plating is performed, and individual router processing is performed to manufacture the inductor-embedded substrate 1.

  As described above, in the inductor-embedded substrate and the manufacturing method thereof according to the present embodiment, a large value inductor can be obtained by increasing the number of turns of the coil, and the substrate in which the inductor is incorporated is used for normal substrate manufacturing. Can be built in the process.

(Fifth embodiment of the present invention)
The substrate with a built-in inductor according to this embodiment will be described with reference to FIGS. FIG. 11 is a perspective view and a cross-sectional view of the inductor built-in substrate according to the present embodiment, and FIG. 12 is a cross-sectional view in each procedure of the method for manufacturing the inductor built-in substrate according to the present embodiment. In addition, in this embodiment, the description which overlaps with each said embodiment is abbreviate | omitted.

  The structure of the inductor-embedded substrate 1 according to this embodiment will be described with reference to FIG. 11A is a perspective view of the inductor-embedded substrate 1 according to the present embodiment, and FIG. 11B is a cross-sectional view when viewed from the direction of arrow a in FIG. 11A. The inductor-embedded substrate 1 according to the present embodiment has a two-core structure in which two inductors are arranged in parallel as in the inductor-embedded substrate 1 shown in FIG. 5 in the second embodiment. Are arranged in parallel. That is, inductors are respectively formed on the front side and the back side across the core material.

  Next, an example of the method for manufacturing the inductor-embedded substrate 1 according to the present embodiment will be described with reference to FIG. First, a core material with copper foil is prepared on both surfaces (FIG. 12A), and a positioning hole is drilled (FIG. 12B). A wiring as a coil is formed by patterning on the front surface side (second layer) and the back surface side (third layer) (FIG. 12C). At this time, positioning uses a hole in the outer frame. Magnetic bodies 5 are mounted on the front side and the back side, respectively (FIG. 12D). At this time, the magnetic body 5 is fixed with a pelletizing agent. Both surfaces are embedded with resin, and each surface is laminated with an interlayer insulating material (FIG. 12E). A hole for a through hole penetrating from the front surface side to the back surface side is drilled (FIG. 12F). At this time, positioning uses a hole in the outer frame. After desmearing, the entire surface is plated (electroless plating and electrolytic plating) (FIG. 12G). A wiring as a coil is formed by patterning on the front surface side (first layer) and the back surface side (fourth layer) (FIG. 12H). At this time, positioning uses a hole in the outer frame. Thereafter, as in the case of the fourth embodiment, patterning using a solder resist, electroless Ni / Au plating, and individualized router processing are performed to manufacture the substrate 1 with a built-in inductor.

  The inductor-embedded substrate 1 manufactured by the above-described manufacturing method has a front-side inductor and a back-side inductor connected in series continuously by wiring patterns and through-holes, similarly to the structure shown in FIG. It is what.

  As described above, in the inductor-embedded substrate and the manufacturing method thereof according to the present embodiment, a large-value inductor can be obtained by using a two-core structure, and the substrate in which the inductor is incorporated is a normal substrate. Can be built in the manufacturing process.

(Other embodiments)
The structure of the substrate with a built-in inductor other than the above embodiments will be described. FIG. 13 shows a modification of the substrate with a built-in inductor shown in FIG. In FIG. 6, the vias 6 formed between the two magnetic bodies 5 are formed in a straight line in the vertical direction, whereas in FIG. 13, the vias 6 are formed between the two magnetic bodies 5. The vias 6 are formed in a zigzag shape. For example, in the case of FIG. 6, since the current is different between the magnetic bodies 5 (inner side) and the outer side, the magnetic flux is saturated only on the inner side, and there is a possibility that a stable inductance cannot be obtained. On the other hand, in the case of FIG. 13, although the inductor itself is somewhat larger, the magnetic flux in each magnetic body 5 is equal on the outer side and the inner side, and a stable inductor can be obtained. In addition, since the via 6 is formed apart, the formation of the via hole is facilitated.

  FIG. 14 is a modification of the inductor-embedded substrate shown in FIG. In FIG. 5, two magnetic bodies 5 are configured as separate bodies, but in FIG. 14, one magnetic body 5 is formed in a closed loop shape. The wiring pattern and via as a coil are formed so as to wind the closed loop magnetic body 5. By doing so, it is possible to obtain an inductor in which magnetic fluxes are stably linked. The loop shape may be a circle, an ellipse, a rectangle, a polygon, or the like, but is preferably a smooth loop shape like a circle or an ellipse in order to efficiently link magnetic flux.

DESCRIPTION OF SYMBOLS 1 Inductor built-in board | substrate 2a, 2b Copper thin film 3 Core material 4 Core board | substrate 5 Magnetic body 6 Via 7 1st coil wiring 8 2nd coil wiring 10 Inductor 11 End part 15 DC / DC converter 16 Capacitor 17 Switching element 18 Diode 20 Power supply module

[0002]
This is a method of pressure bonding. In both techniques, an inductor built-in board is manufactured by embedding an inductor manufactured as a component by embedding it in the board manufacturing process.
Prior Art Literature Patent Literature [0005]
Patent Document 1: Japanese Patent Application Laid-Open No. 2004-31875 Patent Document 2: Japanese Patent Application Laid-Open No. 2004-363162 Patent Document 3: Japanese Patent Application Laid-Open No. 2005-101175 SUMMARY OF THE INVENTION Problems to be Solved by the Invention [0006]
However, in the techniques described in the above patent documents, the manufacturing process is deteriorated because the process of manufacturing the inductor and the process of manufacturing the substrate are separate and independent processes. In addition, since the process of manufacturing the inductor and the process of manufacturing the substrate are independent, there is a possibility that the characteristics of the wiring such as the resistance and capacitance of the board will differ from the characteristics of the wiring such as the resistance of the inductor and the capacity. However, a defect occurs in the connection part of the inductor and the accuracy of the substrate is deteriorated.
[0007]
The present invention makes it possible to manufacture an inductor-embedded substrate very efficiently by making an inductor incorporated in the substrate in the manufacturing process of manufacturing the substrate, and also provides high precision with common wiring characteristics. A substrate with a built-in inductor and a method for manufacturing the same are provided.
Means for Solving the Problems [0008]
A method for manufacturing a substrate with a built-in inductor according to the present invention includes a first wiring step for forming a plurality of strip-shaped wiring patterns on a surface of a core substrate, and excluding at least an end portion of the strip-shaped wiring pattern formed in the first wiring step. A magnetic body mounting step of mounting a solid magnetic body constituting a magnetic circuit formed in advance with dimensions corresponding to the region; an embedding step of filling the magnetic body with a resin made of an insulating material; For connecting an end portion of the wiring pattern and a wiring pattern formed in an upper layer

[0003]
A via hole forming step for forming a via hole, a filling step for filling the via hole formed in the via hole forming step with a conductive material, and the via formed in the filling step is connected to the substrate in the stacking direction. And a second wiring step of forming a plurality of strip-like wiring patterns on the upper metal thin film formed in the filling step so that the wiring is formed as a coil magnetized in a direction perpendicular to the coil.
[0009]
As described above, in the inductor-embedded substrate manufacturing method according to the present invention, an inductor having a magnetic material as a core is formed in a normal substrate manufacturing process, so that a substrate having an inductor embedded therein is manufactured very efficiently. There is an effect that can be done.
[0010]
Also, the wiring as the inductor coil is created in the board manufacturing process, so that the electrical characteristics (resistance, capacitance, etc.) of the wiring of the current flowing in the inductor coil and the wiring of the board are made common. Therefore, it is possible to manufacture a highly accurate substrate with a built-in inductor.
[0011]
In the method for manufacturing a substrate with a built-in inductor according to the present invention, the band-shaped wiring pattern and the via are formed by the same plating process.
[0012]
As described above, in the method for manufacturing an inductor-embedded substrate according to the present invention, wiring as a coil of the inductor is formed by a similar plating process in the substrate manufacturing process. The electrical characteristics (such as resistance and capacitance) can be shared with the other wiring, and it is possible to produce a highly accurate substrate with a built-in inductor.
[0013]
An inductor-embedded substrate according to the present invention includes a plurality of strip-shaped first wiring patterns formed on the surface of a core substrate, and a magnetic circuit formed in advance with dimensions corresponding to a region excluding at least an end portion of the first wiring pattern. A magnetic body that is mounted by placing a solid constituting the structure, an insulating material that fills and molds the first wiring pattern and the magnetic body with a fluid resin material, and a belt-like shape formed on the upper surface of the insulating material A plurality of second wiring patterns, wherein the first wiring pattern and the second wiring pattern are stacked on the core substrate as a coil that is magnetized in a direction perpendicular to the stacking direction of the substrate. They are connected by vias so as to be formed.
[0014]
Thus, in the inductor built-in substrate according to the present invention, the surface of the core substrate is displayed.

[0006]
[0024]
In the inductor built-in substrate manufacturing method according to the present invention, a solid magnetic material constituting a magnetic circuit formed in advance with a dimension equal to or smaller than the size of the cavity is placed in the cavity formed in the core substrate, and the magnetic A magnetic material embedding step for filling the body with a resin made of an insulating material, a wiring layer forming step for forming a wiring layer on the front surface and the back surface of the core base material in which the magnetic material is embedded, and a front surface and a back surface A via hole forming step for forming a via hole for connecting the wiring layer; a filling step for filling the via hole formed in the via hole forming step with a conductive material; and the via formed in the filling step; In addition, the wiring layers formed on the front surface and the back surface of the core base material are formed such that the wiring layers formed on the front surface and the back surface of the core base material are magnetized in a direction perpendicular to the stacking direction of the substrates. Wiring putter It is intended to include a wiring step of forming a.
[0025]
The inductor-embedded substrate manufacturing method according to the present invention includes a second wiring layer forming step in which a wiring layer is formed again on the front surface and the back surface of the wiring pattern formed by the wiring step, the second wiring layer forming step, In addition, the via hole forming step, the filling step, and the wiring step are repeated one or more times to form the coil with a plurality of turns.
[0026]
The method for manufacturing a substrate with a built-in inductor according to the present invention includes a first wiring step of forming a plurality of strip-shaped wiring patterns on the front surface and the back surface of the core substrate, and a front surface and a back surface of the core substrate formed in the first wiring step. A magnetic body mounting step for mounting a solid magnetic body constituting a magnetic circuit formed in advance with a dimension corresponding to a region excluding at least an end of the belt-like wiring pattern, and filling the magnetic body with a resin made of an insulating material Embedding step, forming via holes for connecting end portions of the strip-like wiring patterns and wiring patterns formed in the upper layers of the respective wiring patterns, and forming the via holes A filling step of filling the via hole formed in the step with a conductive material, and a via stack formed in the filling step, and the lamination of the substrate on each of the front surface and the back surface across the core substrate As wire as a coil for the magnetization in a direction perpendicular to the direction are formed, it is intended to include a second wiring step of forming a strip of a plurality of wiring patterns on the upper layer of the metal thin film formed by the filling process.
[0027]
As described above, in the method for manufacturing a substrate with a built-in inductor according to the present invention, an inductor having a magnetic material as a core is formed in a normal substrate manufacturing process.

A method for manufacturing a substrate with a built-in inductor according to the present invention includes a first wiring step for forming a plurality of strip-shaped wiring patterns on a surface of a core substrate, and excluding at least an end portion of the strip-shaped wiring pattern formed in the first wiring step. via for connecting the magnetic mounting step of mounting a magnetic material elements in the region, and the buried step of embedding the magnetic substance with an insulating material and a wiring pattern formed on an end portion and an upper strip of the wiring pattern A via hole forming step for forming a hole, a filling step for filling the via hole formed in the via hole forming step with a conductive material, the via formed in the filling step, and connected to the via in the stacking direction of the substrate. And a second wiring step of forming a plurality of strip-like wiring patterns on the upper metal thin film formed in the filling step so that the wiring is formed as a coil magnetized in a perpendicular direction.

Inductor embedded substrate according to the present invention includes a plurality of first wiring patterns of the strip which is formed on the surface of the core substrate, and the magnetic material to be instrumentation wear region excluding at least the end of the first wiring pattern, the second 1 and the wiring pattern and the magnetic motor Rudo insulating material, and a strip of a plurality of second wiring patterns formed on the upper surface of the insulating material, and said first wiring pattern and the second wiring pattern , those which are connected by vias as is done form the wiring as a coil for the magnetization in a direction perpendicular to the stacking direction of the substrate.

Inductor embedded substrate manufacturing method according to the present invention forms a fit writing magnetic embedding step embedding a magnetic material elements in the core substrate, the wiring layer on the front and back surfaces of the core substrate, wherein the magnetic body is embedded wirings A layer forming step, a via hole forming step for forming a via hole for connecting the wiring layers on the front surface and the back surface, a filling step for filling the via hole formed in the via hole forming step with a conductive material, The via formed in the filling process, and the wiring layer formed on the front surface and the wiring layer formed on the back surface of the core base material become coils that are magnetized in a direction perpendicular to the stacking direction of the substrate. And a wiring step of forming a wiring pattern of the wiring layer on the front surface and the back surface.

The method for manufacturing a substrate with a built-in inductor according to the present invention includes a first wiring step of forming a plurality of strip-shaped wiring patterns on the front surface and the back surface of the core substrate, and a front surface and a back surface of the core substrate formed in the first wiring step. and the magnetic mounting step of mounting a magnetic material elements in the region excluding at least the ends of the strip-shaped wiring pattern, and the buried step of embedding the magnetic substance with an insulating material, and the end portion of the strip of the wiring pattern, the wiring pattern A via hole forming step for forming a via hole for connecting a wiring pattern formed on the upper layer; a filling step for filling the via hole formed in the via hole forming step with a conductive material; and the filling step The wiring is formed so that a wiring is formed as a coil magnetized in a direction perpendicular to the stacking direction of the substrate on each of the front surface and the back surface across the core substrate. The upper layer of the metal thin film formed in step is intended to include a second wiring step of forming a strip of a plurality of wiring patterns.

Claims (11)

A first wiring step of forming a plurality of strip-shaped wiring patterns on the surface of the core substrate;
A magnetic body mounting step of mounting a magnetic body in a region excluding at least an end of the belt-shaped wiring pattern formed in the first wiring step;
An embedding step of embedding the magnetic body with an insulating material;
A via hole forming step for forming a via hole for connecting an end portion of the belt-like wiring pattern and a wiring pattern formed in an upper layer;
A filling step of filling the via hole formed in the via hole forming step with a conductive material;
A plurality of strips are formed on the upper metal thin film formed in the filling step so that the wiring is formed as a coil connected to the via formed in the filling step and magnetized in a direction perpendicular to the stacking direction of the substrate. And a second wiring step of forming the wiring pattern of the above. In the inductor built-in substrate manufacturing method according to claim 1,
The method of manufacturing a substrate with a built-in inductor, wherein the band-shaped wiring pattern and the via are formed by a similar plating process.   A plurality of strip-shaped first wiring patterns formed on the surface of the core substrate, a magnetic body attached to a region excluding at least an end of the first wiring pattern, and the first wiring pattern and the magnetic body are molded. And a plurality of strip-shaped second wiring patterns formed on the upper surface of the insulating material, wherein the first wiring pattern and the second wiring pattern are perpendicular to the stacking direction of the substrate. A substrate with a built-in inductor, wherein wiring is formed so that wiring is formed as a coil magnetized in a direction. The inductor-embedded substrate according to claim 3,
An inductor built-in substrate manufactured by the inductor built-in substrate manufacturing method according to claim 1. The substrate with a built-in inductor according to claim 3 or 4,
A plurality of the inductors are arranged in parallel, coil wirings in the inductors are continuously connected in series, and the magnetization directions of the adjacent inductors are opposite to each other. Inductor built-in board. In the inductor-embedded substrate according to claim 5,
The two magnetic bodies are arranged in parallel, and a plurality of first vias formed along the outer side surfaces of the magnetic bodies, and the magnetic bodies formed along the inner side surfaces of the magnetic bodies. And a second via common to
The first wiring is formed such that the coil formed of the first wiring pattern, the second wiring pattern, the first via, and the second via is alternately wound around each magnetic body every one or a plurality of turns. A substrate with a built-in inductor, wherein a pattern, a second wiring pattern, a first via, and a second via are formed. The substrate with a built-in inductor according to claim 3 or 4,
The inductor-embedded substrate, wherein the magnetic body has a closed loop shape, and the first wiring pattern, the second wiring pattern, and the via are formed as a coil around which the magnetic body is wound. A power supply module using the substrate with a built-in inductor according to any one of claims 3 to 7,
A DC / DC converter connected in series with the inductor is mounted on the top of the inductor, and an output unit and a capacitor are connected in parallel to a subsequent stage portion of the inductor, and the DC / DC converter and the A power supply module, wherein a capacitor is disposed so as to face each other with a magnetic body of the inductor interposed therebetween. A magnetic material embedding step of embedding a magnetic material in the core substrate;
A wiring layer forming step of forming a wiring layer on the front surface and the back surface of the core substrate in which the magnetic body is embedded;
A via hole forming step for forming a via hole for connecting the wiring layers on the front surface and the back surface;
A filling step of filling the via hole formed in the via hole forming step with a conductive material;
The via formed in the filling process, and the wiring layer formed on the front surface and the wiring layer formed on the back surface of the core base material become coils that are magnetized in a direction perpendicular to the stacking direction of the substrate. And a wiring step of forming a wiring pattern of the wiring layer on the front surface and the back surface. The method for manufacturing a substrate with a built-in inductor according to claim 9,
Including a second wiring layer forming step of forming a wiring layer again on the front and back surfaces of the wiring pattern formed by the wiring step;
The second wiring layer forming step, the via hole forming step, the filling step, and the wiring step are repeated one or more times to form the coil with a plurality of turns. Substrate manufacturing method. A first wiring step of forming a plurality of strip-shaped wiring patterns on the front surface and the back surface of the core substrate;
A magnetic body mounting step of mounting a magnetic body in a region excluding at least an end portion of a belt-like wiring pattern on the front surface and the back surface of the core substrate formed in the first wiring step;
An embedding step of embedding the magnetic body with an insulating material;
A via hole forming step for forming a via hole for connecting the end of the belt-like wiring pattern and a wiring pattern formed in an upper layer of each wiring pattern;
A filling step of filling the via hole formed in the via hole forming step with a conductive material;
The filling is performed such that wiring is formed as a coil that is connected to the via formed in the filling step and is magnetized in a direction perpendicular to the stacking direction of the substrate on each of the front and back surfaces across the core substrate. And a second wiring step of forming a plurality of strip-like wiring patterns on the upper metal thin film formed in the step.

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