JP2014199944A - Inductor built-in component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inductor built-in component capable of being downsized and thinned and obtaining sufficient inductance.SOLUTION: An inductor built-in component 70 includes a plurality of columnar outside penetrating metal parts 78A composed of a magnetic material so as to surround an outside of a planar coil 75. A columnar inside penetrating metal parts 78B are also provided at an inner side of the planar coil 75. By providing a first metal layer 72 and a second metal layer 77 composed of a magnetic material at an upper part and a lower part of a layer at which the planar coil 75 is formed to surround the planar coil 75 with a magnetic material, leakage of a magnetic flux is prevented and inductance is heightened.

Description

  The present invention relates to an inductor built-in component, and more particularly to an inductor built-in component including a structure in which a planar coil layer is formed on a substrate.

  An inductor (choke coil) is used in a smoothing circuit, various filter circuits, and the like. Conventional inductors include a wound inductor in which an electric wire is wound around a core made of a magnetic material, and a planar inductor in which a spiral coil conductor is formed in a planar shape.

  Patent Document 1 describes an inductor having a structure in which planar coil layers formed on both surfaces of a circuit board are sandwiched between magnetic films.

  In Patent Document 2, a coil is mounted as a mounting component on a circuit board together with a semiconductor chip (LSI), a resistor, a capacitor, and a crystal, and the upper surface of the circuit board on which these components are mounted is a sealing body. And a module component sealed with a metal film (shield).

JP-A-5-198445 JP 2004-56155 A

  However, when mounting a winding type inductor component on a circuit board, it is necessary to secure a certain amount of height and mounting area.

  As a countermeasure, there is a method in which an inductor element composed of a planar coil layer is formed on a circuit board in order to reduce the size and thickness of an electronic device. However, since the magnetic flux leaks to the external space only with the planar coil layer, a high inductance cannot be obtained.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a component with a built-in inductor that incorporates an inductor element that can be reduced in size and thickness and can provide sufficient inductance.

  In order to solve the above problems, according to one aspect of the present invention, an intermediate substrate on which a planar coil is formed, a lower substrate that is disposed under the intermediate substrate and includes a first metal layer on a lower surface side, An upper substrate disposed on the intermediate substrate and provided with a second metal layer on the upper surface side, and formed through the upper substrate to the lower substrate and connected to the first and second metal layers A plurality of outer penetrating metal portions disposed so as to surround the outer surface of the planar coil, and penetrated from the upper substrate to the lower substrate, and connected to the first and second metal layers An inner penetrating metal portion disposed inside the planar coil, wherein the first metal layer, the second metal layer, the outer penetrating metal portion, and the inner penetrating metal portion are magnetic flux leakage Inductor built-in part, characterized in that it is made of a prevention metal There is provided.

  The inductor built-in component according to the above aspect has a structure in which the upper, lower and surroundings of the planar coil layer are surrounded by the first metal layer, the second metal layer, the outer penetrating metal portion and the inner penetrating metal portion made of a magnetic flux leakage preventing metal. Yes. Therefore, the leakage of the magnetic flux generated by the current flowing through the planar coil layer is prevented, the number of linkages between the planar coil layer and the magnetic flux can be increased, and a high inductance can be obtained.

  In this way, by configuring the inductor with a planar coil layer, it becomes possible to reduce the size and thickness, and to obtain a sufficient inductance.

  Also in the present invention, the inductor built-in components constituting the semiconductor chip and the power supply circuit can be easily mounted on the same substrate.

  As described above, according to the inductor built-in component of the present invention, it is possible to reduce the size and thickness, and to obtain a sufficient inductance.

FIG. 1 is a block diagram showing a configuration of a power source of a semiconductor chip mounting component according to related technology. FIG. 2 is a circuit diagram showing an equivalent circuit of the power supply wiring of the related art. FIG. 3A is a diagram showing a load variation (current change) of a semiconductor chip (LSI) in the related art, and FIG. 3B is a diagram similarly showing a change in power supply voltage of the semiconductor chip. 4A to 4B are perspective views showing a method of manufacturing the component with a built-in inductor according to the first embodiment of the present invention in the order of steps. FIG. 5 is a cross-sectional view taken along the line II of FIG. FIG. 6 is a cross-sectional view showing a component with a built-in inductor according to the first embodiment of the present invention. FIG. 7 is a schematic view (cross-sectional view) showing a state in use of the component with a built-in inductor according to the first embodiment of the present invention. FIG. 8 is a cross-sectional view showing a method of manufacturing a component with a built-in inductor according to a second embodiment of the present invention. 9 is a perspective view showing the structure shown in FIG. 8 in an exploded state. FIG. 10 is a perspective view showing a method of manufacturing a component with a built-in inductor according to the second embodiment of the present invention. 11A to 11C are perspective views showing a method of manufacturing a component with a built-in inductor according to a third embodiment of the present invention in the order of steps. FIG. 12 is a cross-sectional view showing a component with a built-in inductor according to a third embodiment of the present invention. FIGS. 13A to 13C are perspective views showing the method of manufacturing a component with a built-in inductor according to the fourth embodiment of the present invention in the order of steps (No. 1). 14 (a) to 14 (b) are perspective views showing the method of manufacturing a component with a built-in inductor according to the fourth embodiment of the present invention in the order of steps (No. 2). FIG. 15 is a cross-sectional view showing a component with a built-in inductor according to a fourth embodiment of the present invention. FIG. 16: is a perspective view which shows the manufacturing method of the components with a built-in inductor of 5th Embodiment of this invention (the 1). FIG. 17: is a perspective view which shows the manufacturing method of the components with a built-in inductor of 5th Embodiment of this invention (the 2). FIG. 18 is a cross-sectional view showing a method of manufacturing a component with a built-in inductor according to a fifth embodiment of the present invention. FIG. 19 is a cross-sectional view showing a part with a built-in inductor according to a fifth embodiment of the present invention.

(Related technology)
With the miniaturization of LSI (Large Scale Integration; hereinafter referred to as semiconductor chip) such as FPGA (Field Programmable Gate Array) and microprocessor and the improvement of processing speed, the semiconductor chip is supplied with low voltage and large current. It has been demanded.

  FIG. 1 is a block diagram showing a configuration of a power source of a semiconductor chip mounting component according to related technology. As shown in FIG. 1, a power supply circuit 1 for reducing the external power supply voltage and supplying power to the semiconductor chip 5 is provided in the vicinity of the semiconductor chip 5. The power supply circuit 1 is also called a POL (Point of Load) power supply.

  The power supply circuit 1 includes a DC / DC converter (switching power supply) 2 for generating a DC voltage different from the input DC voltage, a choke coil 3 and a smoothing capacitor 4. The choke coil 3 and the smoothing capacitor 4 constitute an output low-pass filter, removes switching noise (ripple noise) generated in the DC / DC converter 2, and smoothes the output voltage. In the example shown in FIG. 1, the power supply circuit 1 has a DC / DC converter 2, a choke coil 3, and a smoothing capacitor 4 connected in parallel, and can output a large current.

  In recent years, the fluctuation range of current consumption has been expanded with the increase in current consumption of semiconductor chips. For example, when a semiconductor chip performs memory access or when performing arithmetic processing with a high-speed clock, a current that is more than twice that when the semiconductor chip is stationary flows. A case of reaching 20 A or more is also assumed. On the other hand, the allowable voltage range of the power supply voltage of the semiconductor chip is becoming narrower as the voltage of the semiconductor chip is lowered.

  FIG. 2 is a circuit diagram showing an equivalent circuit of the power supply wiring of the related art. FIG. 3A is a diagram showing a load fluctuation (current change) of a related-art semiconductor chip (LSI), and FIG. 3B is a diagram showing a voltage change in the vicinity of the power supply terminal of the semiconductor chip.

As shown in FIG. 2, a plurality of decoupling capacitors C _{1 to} C ₃ are connected to the power supply wiring so as to cope with fluctuations in current consumption of the semiconductor chip 5. The decoupling capacitors C _{1 to} C ₃ discharge and supply power to the semiconductor chip 5 as indicated by arrows 1 to 3 in FIG. 2 when the consumption current of the semiconductor chip 5 increases.

The power supply wiring between the power supply circuit 1 and the semiconductor chip 5 has a parasitic resistance r and a parasitic inductance L (also referred to as wiring impedance including r and L). Also the decoupling capacitor C ₁ -C _3, equivalent series resistance shown by reference numeral r _c1 ~r _c3 (ESR) and Equivalent Series Inductance indicated by reference numeral L _c1 ~L _c3 (ESL) is present.

As shown in FIG. 3A, when the consumption current of the semiconductor chip 5 increases rapidly, the power supply circuit 1 and the decoupling capacitors C _{1 to} C _{3 are} affected by the wiring impedance and the decoupling capacitor ESR and ESL. Current supply to the semiconductor chip 5 is delayed.

Due to this delay in current supply, a voltage dip is generated in which the voltage _{Vcc-INT at} the power supply terminal of the semiconductor chip 5 temporarily decreases by ΔV _D as shown in FIG. If the voltage V _cc-INT when the voltage dip occurs is lower than the minimum operating voltage V _{L at} which the LSI can operate, the semiconductor chip 5 may malfunction.

  In general, when the wiring resistance r and the inductance L of the power supply wiring are large, that is, when the power supply wiring is longer, the delay in current supply from the power supply circuit 1 becomes large, so that the voltage dip of the power supply terminal of the semiconductor chip 5 increases accordingly. .

  Therefore, in order to suppress the voltage dip, it is conceivable to shorten the length of the power supply wiring by mounting the power supply circuit 1 as close as possible to the semiconductor chip 5 on the same circuit board to form a module component. In order to realize such module parts, it is necessary to make the choke coil 3 of the power supply circuit 1 small and thin.

  However, for smoothing the power supply of the power supply circuit 1, a choke coil having an inductance of several hundred nH to several thousand nH is necessary. When a conventional surface mount type component is applied, the area occupied by the choke coil increases and the size is reduced. It is difficult to achieve this easily.

  On the other hand, when the inductor is constituted by a planar coil layer formed in a spiral shape on the circuit board, the mounting volume is reduced, but the inductance required for removing power supply noise cannot be obtained. The reason will be described below.

In general, when N · Φ ₁ is the number of times the magnetic flux generated when a current I ₁ is passed through a coil having N turns to the coil itself, the proportional relationship shown in (1) below is established. .

N ・ Φ ₁ ∝I ₁ (1)
Here, N is the number of turns of the coil, Φ ₁ is the number of magnetic fluxes linked to the coil, and I ₁ is the current flowing through the coil. That is, the number of times N · Φ _{1 at} which the magnetic flux generated when a current I ₁ is passed through a coil having N turns is linked to the coil itself is proportional to the current I ₁ .

When the proportionality constant of the above-described proportionality relationship (1) is L ₁ , the equation (1) is expressed as the following equation (2).

N · Φ ₁ = L ₁ · I ₁ (2)
Here, the proportionality constant L ₁ is defined as the self-inductance of the coil. That is, the proportionality constant L ₁ is proportional to the number of magnetic fluxes linked to the electric path when a unit current is passed through the coil, as shown in the following equation (3).

L ₁ = N · Φ ₁ / I ₁ (3)
Therefore, the self-inductance L ₁ increases as the number of magnetic fluxes linked to the coil increases.

  However, in an inductor composed of only a planar coil layer, the magnetic flux generated by the current flowing in the planar coil layer is radiated into the space and leaks, and the number of magnetic fluxes passing near the center of the planar coil is reduced. For this reason, the number of linkages between the planar coil layer and the magnetic flux decreases, and high self-inductance cannot be obtained.

  Accordingly, a component with a built-in inductor that incorporates an inductor element that can be reduced in size and thickness and that can provide a large inductance is desired.

  By the way, in the permanent magnet, a metal member called a yoke is used in order to increase the attractive force. This yoke is a frame (case) made of a material with high magnetic permeability such as soft iron, and is disposed so as to cover the portion from the upper surface to the side surface of the thin plate-like permanent magnet. The yoke collects the magnetic flux emitted from the magnetic pole on the upper surface side of the permanent magnet, and concentrates the magnetic flux on the end of the yoke disposed on the side surface of the permanent magnet.

  In this way, the yoke acts to move the magnetic pole on the upper surface side of the permanent magnet to the lower surface side of the permanent magnet (to bring the N pole and the S pole closer), thereby increasing the magnetic flux density on the lower surface side of the permanent magnet. Increase the attractive force of the permanent magnet. The action of the yoke described above can also be obtained when a permanent magnet is used as an electromagnet.

  In view of the above knowledge, this inventor created embodiment described below.

(First embodiment)
4A and 4B are perspective views showing a method of manufacturing the component with a built-in inductor according to the first embodiment of the present invention, FIG. 5 is a cross-sectional view taken along the line II of FIG. 4A, and FIG. It is sectional drawing which shows the component with a built-in inductor of 1st Embodiment of invention.

  Hereinafter, the inductor built-in component according to the first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIGS. 4A, 5, and 6, in the inductor built-in component 10 of the first embodiment, the planar coil layer 12 is formed on the upper surface of the substrate 11. As the substrate 11, a substrate made of FR4 (glass epoxy resin substrate), bakelite, various organic materials, silicon (Si), or the like can be used. The planar coil layer 12 is made of a conductive wiring material such as copper or aluminum. In the illustrated example, the planar coil layer 12 is wound in a square shape, but the present embodiment is not limited to this and may be wound in a polygonal shape or a circular shape. When the coil layer 12 is formed from copper, the coil layer 12 is formed by a semi-additive method or the like.

  As shown in FIGS. 4B and 6, the substrate 11 and the planar coil layer 12 are covered with an insulating layer 13 made of resin. The insulating layer 13 is formed by sticking a semi-cured resin sheet or applying a liquid resin. Further, external connection terminals 15 (FIG. 6) connected to both ends of the planar coil layer 12 are provided on the lower side of the substrate 11.

  Further, a magnetic flux leakage prevention metal cap 14 having a recess 14 a formed on the lower surface side is attached to the substrate 11. The magnetic flux leakage prevention metal cap 14 is made of iron (soft iron), cobalt, nickel, or an alloy thereof and a metal material (ferromagnetic flux leakage prevention metal) exhibiting ferromagnetism. The magnetic flux leakage prevention metal cap 14 is manufactured, for example, by processing a thin plate of magnetic flux leakage prevention metal into a concave shape by press working or the like. The magnetic flux leakage prevention metal cap 14 covers the portion from the upper side of the planar coil layer 12 to the side surface of the substrate 11 so that the substrate 11, the planar coil layer 12 and the insulating layer 13 are accommodated in the recess 14 a.

  FIG. 7 is a schematic view (cross-sectional view) showing a state in use of the component with a built-in inductor according to the first embodiment of the present invention.

  As shown in FIG. 7, in the inductor built-in component 10 according to the first embodiment, when a current is passed through the planar coil layer 12 via the connection terminal 15, a magnetic flux is generated around the planar coil layer 12. Since the magnetic flux leakage prevention metal cap 14 is made of a ferromagnetic metal capable of preventing magnetic flux leakage, the magnetic flux generated in the planar coil layer 12 is collected and the magnetic flux is guided to the lower end portion of the magnetic flux leakage prevention metal cap 14. Therefore, according to the inductor built-in component 10 of the first embodiment, the number of linkages between the planar coil layer 12 and the magnetic flux can be increased by preventing the leakage of the magnetic flux generated in the planar coil layer 12. High inductance can be obtained.

  Further, in the inductor built-in component 10 of the present invention, the planar coil layer 12 is formed on the substrate 11 with a thin film, so that the size and thickness can be reduced.

  As a result, the semiconductor chip and the inductor built-in component 10 constituting the power supply circuit can be easily mounted on the same substrate. As a result, since the power supply wiring can be set to the shortest, a voltage drop can be prevented and a stable operation of the semiconductor chip can be realized.

(Second Embodiment)
FIG. 8 is a cross-sectional view showing a method of manufacturing a component with a built-in inductor according to a second embodiment of the present invention. 9 is a perspective view showing the structure shown in FIG. 8 in an exploded state. FIG. 10 is a perspective view showing a method of manufacturing a component with a built-in inductor according to the second embodiment of the present invention. 8 corresponds to a cross section taken along line II-II in FIG. The component with a built-in inductor according to the second embodiment is characterized in that it has a laminated planar coil in which a plurality of planar coil layers are laminated.

  Hereinafter, the component with a built-in inductor according to the second embodiment will be described together with a manufacturing method thereof with reference to FIGS.

  First, as shown in FIGS. 8 and 9, a substrate 21 is prepared, and a first planar coil layer 31 made of copper or the like is formed on the upper surface of the substrate 21. The first planar coil layer 31 is formed by a semi-additive method or the like.

  Next, the first insulating layer 22 is formed on the substrate 21 and the first planar coil layer 31. The first insulating layer 22 is formed by sticking a semi-cured resin sheet or applying a liquid resin. Subsequently, the first insulating layer 22 is laser processed to form a via hole 22 a that reaches one end of the first planar coil layer 31.

  Thereafter, the second planar coil layer 32 is formed on the first insulating layer 22 and in the via hole 22a. Thereby, the 2nd plane coil layer 32 connected with the 1st plane coil layer 31 via via hole 22a is obtained.

  Next, the second insulating layer 23 is formed on the first insulating layer 22 and the second planar coil layer 32. Further, a via hole 23 a is formed in the second insulating layer 23. Thereafter, a third planar coil layer 33 connected to the second planar coil layer 32 through the via hole 23 a is formed on the second insulating layer 23.

  Thereafter, the same process is repeated to form the third insulating layer 24 and the via hole 24a, the fourth planar coil layer 34, the fourth insulating layer 25 and the via hole 25a, and the fifth planar coil layer 35 sequentially. Further, these steps correspond to a build-up method used when manufacturing a build-up substrate.

  Thereafter, the fifth insulating layer 26 is formed on the fourth insulating layer 25 and the fifth planar coil layer 35. Subsequently, a pair of connection terminals 36 are connected to the bottom surface of the substrate 21. One of the connection terminals 36 is electrically connected to one end of the first planar coil layer 31 by wiring (not shown), and the other of the connection terminals 36 is one end of the fifth planar coil layer 35 by wiring (not shown). And electrically connected.

  As described above, the laminated planar coil 38 in which the first to fifth planar coil layers 31 to 35 laminated on the substrate 21 are interconnected via the via holes 22a, 23a, 24a, and 25a is completed.

  Next, as shown in FIGS. 8 and 10, a magnetic flux leakage prevention metal cap 37 is attached to the substrate 11 on which the laminated planar coil 38 is formed. The magnetic flux leakage prevention metal cap 37 has a concave portion 37a on the lower surface side, and covers the portion from the upper side to the side surface of the laminated planar coil 38 so as to accommodate the entire laminated planar coil 38 in the recessed portion 37a. . The magnetic flux leakage prevention metal cap 37 is made of the same ferromagnetic metal as the magnetic flux leakage prevention metal cap 14 shown in FIG.

  Thus, the inductor built-in component 20 according to the second embodiment is completed.

  The inductor built-in component 20 of the second embodiment includes a laminated planar coil 38 and a magnetic flux leakage prevention metal cap 37 disposed on the side surface from above. In the laminated planar coil 38, the first to fifth planar coil layers 31, 32, 33, 34, and 35 are laminated on the substrate 21 via the first insulating layer 22 to the fourth insulating layer 25. The first to fifth planar coil layers 31, 32, 33, 34, and 35 are interconnected via via holes 22a, 23a, 24a, and 25a.

  The magnetic flux leakage prevention metal cap 37 has a concave portion 37 a on the lower surface side, and covers the portion from the upper side of the laminated planar coil 38 to the side surface of the substrate 21 so that the recessed portion 37 a accommodates the laminated planar coil 38. ing.

  Also in the inductor built-in component 20 of the second embodiment as described above, the magnetic flux leakage is prevented and sufficient inductance is obtained as in the above-described inductor built-in component 10 shown in FIG.

  Furthermore, in the inductor built-in component 20 of the second embodiment, a thin planar coil layer is laminated on the substrate 21 to constitute the inductor, so that it is smaller and thinner than the case where a conventional spiral inductor component is mounted. Can be achieved.

  As a result, the semiconductor chip and the inductor built-in component 20 constituting the power supply circuit can be easily mounted on the same substrate. As a result, since the power supply wiring can be set to the shortest, a voltage drop can be prevented and a stable operation of the semiconductor chip can be realized.

  In the above description, the case where five planar coil layers are laminated as the laminated planar coil 38 of the component 20 with a built-in inductor is exemplified, but the number of planar coil layers is not limited to five, and n layers ( n can be an integer of 2 or more.

(Third embodiment)
11A to 11C are perspective views showing a method of manufacturing a component with a built-in inductor according to a third embodiment of the present invention in the order of steps. FIG. 12 is a cross-sectional view showing a part with a built-in inductor according to the third embodiment. The cross section shown in FIG. 12 corresponds to the line III-III in FIG. The third embodiment is characterized in that a semiconductor chip and a power supply circuit are arranged on a substrate in addition to a planar coil layer.

  The inductor built-in component according to the third embodiment will be described below.

  As shown in FIG. 11A, a wiring board 41 is prepared, and a planar coil layer 42 is formed on the upper surface thereof. The planar coil layer 42 is formed along the peripheral edge of the wiring board 41. By forming the planar coil layer 42 along the peripheral edge of the wiring board 41, the space on the upper surface of the wiring board 41 can be used effectively.

  Next, the DC / DC converter 43, the semiconductor chip 44, and the capacitor 45 (passive component) are mounted inside the planar coil layer 42 on the wiring substrate 41. One end of the planar coil layer 42 is connected to the output terminal of the DC / DC converter 43 via the wiring (not shown) of the wiring board 41. The other end of the planar coil layer 42 is connected to a capacitor 45 and a power input terminal (not shown) of the semiconductor chip 44. The planar coil layer 42, the DC / DC converter 43 and the capacitor 45 described above constitute a power supply circuit for supplying power to the semiconductor chip 44. External connection terminals 46 are provided on the lower surface side of the wiring board 41.

  Next, as shown in FIG. 11B, an insulating layer 47 that covers the wiring substrate 41, the planar coil layer 42, the DC / DC converter 43, the semiconductor chip 44, and the capacitor 45 is formed. The insulating layer 47 is formed from a resin or the like. In this manner, the planar coil layer 42, the DC / DC converter 43, the semiconductor chip 44, the capacitor 45, and the insulating layer 47 are arranged on the wiring board 41, and the circuit board 41A is obtained.

  Next, as shown in FIG. 11C, a magnetic flux leakage prevention metal cap 48 having a recess 48a on the lower surface side is attached to the circuit board 41A. The magnetic flux leakage prevention metal cap 48 is made of a metal material (magnetic flux leakage prevention metal) that is ferromagnetic (ferrous iron), cobalt, nickel, or an alloy thereof and exhibits ferromagnetism.

  Between the magnetic flux leakage prevention metal cap 48 and the circuit board 41A, a heat conductive resin such as silicon grease having a high thermal conductivity is filled, or a thermosetting adhesive is applied to the magnetic flux leakage prevention metal. A cap 48 is attached. In particular, when the heat conductive resin is filled, the heat of the semiconductor chip 44 can be sufficiently radiated from the magnetic flux leakage prevention metal cap 48 to the outside through the heat conductive resin. That is, the magnetic flux leakage prevention metal cap 48 can also be used as a heat sink for the semiconductor chip 44. In this case, nickel having high thermal conductivity is preferably used for the magnetic flux leakage prevention metal cap 48.

  Thus, the inductor built-in component 40 of the third embodiment is completed.

  As shown in FIGS. 11C and 12, in the inductor built-in component 40 of the third embodiment, a planar coil layer 42 is formed on a wiring board 41, and a DC / DC converter 43 is disposed inside the planar coil layer 42. A semiconductor chip 44 and a capacitor 45 are mounted. The planar coil layer 42, the capacitor 45, and the DC / DC converter 43 constitute a power supply circuit for the semiconductor chip 44. Further, the wiring substrate 41, the DC / DC converter 43, the semiconductor chip 44 and the capacitor 45 are covered with an insulating layer 47.

  The magnetic flux leakage prevention metal cap 48 is mounted so as to cover the circuit board 41A from the upper side of the planar coil layer 42 to the side surface of the wiring board 41 so as to accommodate the circuit board 41A in the recess 48a.

  As described above, in the inductor built-in component 40 of the third embodiment, the portion from the upper side of the planar coil layer 42 to the side surface of the wiring board 41 is covered with the magnetic flux leakage prevention metal cap 48. Thereby, since leakage of the magnetic flux generated in the planar coil layer 42 can be prevented, high inductance can be obtained from the planar coil layer 42. Further, since the inductor element is formed from the thin planar coil layer 42, the thickness can be reduced.

  Therefore, the power supply circuit including the planar coil layer 42 can be arranged on the same wiring substrate 41 as the semiconductor chip 44. Further, since the planar coil layer 42 is formed along the peripheral edge of the wiring board 41 and the semiconductor chip 44 and the power supply circuit are mounted on the inner side thereof, the space on the wiring board 41 can be used effectively, and the circuit board 41A. Can be made smaller.

  In this manner, a thin planar coil layer 42 (inductor element) capable of obtaining sufficient inductance can be formed in the immediate vicinity of the semiconductor chip 44 together with the DC / DC converter 43 and the capacitor 45. As a result, the voltage drop of the power supply wiring can be prevented, and the stable operation of the semiconductor chip 44 can be realized.

(Fourth embodiment)
FIGS. 13A to 13C are perspective views showing the method of manufacturing a component with a built-in inductor according to the fourth embodiment of the present invention in the order of steps (No. 1). 14 (a) to 14 (b) are perspective views showing the method of manufacturing a component with a built-in inductor according to the fourth embodiment of the present invention in the order of steps (No. 2). The inductor-embedded component of the fourth embodiment is different from the inductor-embedded component 40 shown in FIG. 12 in that a planar coil layer is provided on the semiconductor chip and the power supply circuit via an insulating layer.

  Hereinafter, the inductor built-in component according to the fourth embodiment will be described together with its manufacturing method with reference to FIGS.

  As shown in FIG. 13A, first, a wiring board 51 having metal pillars 52a and 52b provided on the upper surface is prepared. The metal column 52a is formed at a portion corresponding to an inner peripheral side end portion of the planar coil layer described later, and the metal column 52b is formed at a portion corresponding to an outer peripheral side end portion of the planar coil layer.

  Next, a DC / DC converter 53, a semiconductor chip 54, a capacitor 55 (passive component), and the like are mounted on the upper surface of the wiring board 51. External connection terminals 56 are provided on the lower surface side of the wiring board 51.

  Next, as shown in FIG. 13B, a lower insulating layer 57 made of resin or the like is formed on the wiring substrate 51, the metal pillars 52a and 52b, the DC / DC converter 53, the semiconductor chip 54, and the capacitor 55. . Subsequently, by performing drilling and laser processing on the lower insulating layer 57, openings 57a and 57b reaching the upper surfaces of the metal columns 52a and 52b are formed, respectively.

  Thereafter, as shown in FIG. 13C, a spiral planar coil layer 58 is formed on the insulating layer 57 and the openings 57a and 57b. The planar coil layer 58 is formed by, for example, a semi-additive method. One end on the outer peripheral side of the planar coil layer 58 is connected to the DC / DC converter 53 via the metal pillar 52b, and one end on the inner peripheral side of the planar coil layer 58 is connected to the capacitor 55 and the semiconductor chip 54 via the metal pillar 52a. Is done. The planar coil layer 58, the capacitor 55, and the DC / DC converter 53 constitute a power supply circuit for supplying power to the semiconductor chip 54.

  Next, as shown in FIG. 14A, the upper insulating layer 59 is formed on the lower insulating layer 57 and the planar coil layer 58. The upper insulating layer 59 can be formed by applying a resin material such as a solder resist.

  In this way, the DC / DC converter 53, the semiconductor chip 54, and the capacitor 55 are mounted on the wiring substrate 51, and the planar coil layer 58 and the upper insulating layer 59 are disposed thereon via the lower insulating layer 57. As a result, the circuit board 51A is configured.

  Thereafter, as shown in FIGS. 14B and 15, a magnetic flux leakage prevention metal cap 60 having a recess 60a on the lower surface side is attached to the circuit board 51A. The magnetic flux leakage prevention metal cap 60 is attached so as to cover the portion from the upper side of the planar coil layer 58 to the side surface of the circuit board 51 so that the circuit board 51A is accommodated in the recess 60a. The magnetic flux leakage prevention metal cap 60 is made of a metal material (magnetic flux leakage prevention metal) which is one of iron (soft iron), cobalt and nickel, or an alloy thereof and exhibits ferromagnetism.

  Magnetic flux leakage prevention metal cap 60 and circuit board 51 are filled with a heat conductive resin such as silicon grease having a high thermal conductivity, or a thermosetting adhesive is applied to prevent magnetic flux leakage. A metal cap 60 is attached. In particular, when the thermally conductive resin is filled, the heat of the semiconductor chip 54 can be sufficiently radiated from the magnetic flux leakage preventing metal cap 60 to the outside through the thermally conductive resin. For this reason, also in this embodiment, the magnetic flux leakage prevention metal cap 60 can be used as a heat sink for the semiconductor chip 54.

  Thus, the inductor built-in component 50 of the fourth embodiment is completed.

  FIG. 15 is a schematic diagram illustrating a part with a built-in inductor according to the fourth embodiment. Note that the left side of FIG. 15 shows a cross section of the portion along the line IV-IV in FIG. 14B, and the right side shows a cross section of the connection portion between the metal column and the planar coil layer.

  As shown in FIG. 15, the inductor built-in component 50 of the fourth embodiment includes a circuit board 51 </ b> A and a magnetic flux leakage prevention metal cap 60 that covers the upper side and the side thereof.

  In the circuit board 51A, the DC / DC converter 53, the semiconductor chip 54, and the capacitor 55 are mounted on the wiring board 51 on which the metal pillars 52a and 52b are formed. A lower insulating layer 57 is formed on the wiring board 51 to cover them. Further, a planar coil layer 58 connected to the metal pillars 52 a and 52 b through openings 57 a and 57 b formed in the lower insulating layer 57 is formed on the lower insulating layer 57. Further, an upper insulating layer 59 that covers the lower insulating layer 57 and the planar coil layer 58 is formed.

  The magnetic flux leakage prevention metal cap 60 covers the portion from the upper side of the planar coil layer 58 to the side surface of the circuit board 51A so that the circuit board 51A is accommodated in the recess 60a.

  The inductor built-in component 50 according to the fourth embodiment can prevent magnetic flux leakage to the outside as in the above-described inductor built-in component 40 shown in FIG. 12, so that the inductance of the planar coil layer 58 can be further increased.

  Further, in the inductor built-in component 50, since the planar coil layer 58 is formed on the semiconductor chip 54 and the power supply circuit via the lower insulating layer 57, the planar coil is not affected by the layout of these components. Layer 58 can be formed into a desired shape.

  In addition, a power supply circuit including the planar coil layer 58 can be mounted on the same wiring substrate 51 as the semiconductor chip 54. In this manner, a thin planar coil layer 58 (inductor element) capable of obtaining sufficient inductance can be formed in the immediate vicinity of the semiconductor chip 54 together with the DC / DC converter 53 and the capacitor 55. As a result, the voltage drop of the power supply wiring can be prevented and the stable operation of the semiconductor chip 54 can be realized.

  Also in this embodiment, the planar coil layer 58 may be stacked by n layers (n is an integer of 2 or more).

(Fifth embodiment)
16 and 17 are perspective views showing a method for manufacturing the inductor built-in component according to the fifth embodiment. FIG. 18 is a cross-sectional view illustrating a method for manufacturing a component with a built-in inductor according to a fifth embodiment. FIG. 19 is a cross-sectional view showing a part 70 with a built-in inductor according to the fifth embodiment. FIG. 19 shows a cross section taken along line V-V in FIG.

  The component with a built-in inductor according to the fifth embodiment includes a metal layer made of magnetic flux leakage preventing metal disposed on the upper and lower sides of the planar coil layer, and a through metal portion made of magnetic flux leakage preventing metal disposed on the outer and inner sides of the planar coil layer. And having a structure surrounding the top and bottom and the periphery of the planar coil layer.

  Hereinafter, the inductor built-in component according to the fifth embodiment will be described together with its manufacturing method.

  First, as shown in FIG. 16, a lower substrate 71 having a first metal layer 72 on the lower surface side, an intermediate substrate 74 having a planar coil layer 75 formed on the upper surface, and a second metal layer 77 on the upper surface side. An upper substrate 76 is prepared. The lower substrate 71, the intermediate substrate 74, and the upper substrate 77 can be made of the same material as the substrate 11 of the first embodiment.

  The first metal layer 72 of the lower substrate 71 is made of a magnetic flux leakage preventing metal. The magnetic flux leakage preventing metal is made of a metal material that is ferromagnetic and is one of iron (soft iron), cobalt, nickel, or an alloy thereof. When the magnetic flux leakage prevention metal is nickel, a first metal layer is prepared by preparing a substrate on which a copper layer (copper foil) is adhered and forming a nickel layer on the copper layer by electrolytic plating. 72 is obtained.

  The intermediate substrate 74 is obtained by forming the planar coil layer 76 on the upper surface of the intermediate substrate 74 by a semi-additive method or the like.

  The second metal layer 77 formed on the upper substrate 76 is made of the same metal as the first metal layer 72.

  In the above description, the case where the first metal layer 72 and the second metal layer 77 are constituted by a copper layer and a magnetic flux leakage prevention metal layer formed on the copper layer is exemplified. However, the first metal layer 72 and the second metal layer 77 may be composed of only the magnetic flux leakage prevention metal layer. In this case, the lower substrate 71 provided with the first metal layer 72 is produced by forming a magnetic flux leakage preventing metal layer on the lower surface of the substrate by sputtering or the like. The same applies to the upper substrate 76 provided with the second metal layer 77.

  Next, as illustrated in FIG. 17, the lower substrate 71, the intermediate substrate 74, and the upper substrate 76 are bonded together using an adhesive to form a stacked body 80. Thereafter, an insulating layer (not shown) is formed so as to cover the surface of the first metal layer 72 and the surface of the second metal layer 77.

  Next, as shown in FIG. 17, a plurality of through holes penetrating from the upper surface of the lower substrate 71 to the lower surface of the upper substrate 77 in a portion surrounding the outside of the planar coil layer 75 by drilling the laminated body 80. Form TH. Further, a through hole TH penetrating from the upper surface of the lower substrate 71 to the lower surface of the upper substrate 77 is also formed inside the planar coil layer 75.

  Next, as shown in FIG. 18, the laminated body 80 in which the through hole TH is formed is disposed on the plating power supply material 90, and the inside of the through hole TH is obtained by electrolytic plating using the plating power supply material 90 as a power supply path. For example, a metal exhibiting ferromagnetism (magnetic flux leakage prevention metal) such as nickel (Ni) is formed. The through hole TH may be filled with iron (soft iron) or cobalt. As a result, a plurality of outer through metal portions 78A arranged so as to surround the planar coil layer 75 and an inner through metal portion 78B arranged inside the planar coil layer 75 are formed. The outer through metal portion 78A and the inner through metal portion 78B are formed so as to penetrate from the lower substrate 71 to the upper substrate 76 and are electrically connected to the first metal layer 72 and the second metal layer 77. The

  Thereafter, as shown in FIG. 19, external connection terminals 79 that are electrically connected to the planar coil layer 75 are formed on the lower surface of the laminate 80.

  Thus, the inductor built-in component 70 of the fifth embodiment is completed.

  As shown in FIG. 19, in the inductor built-in component 70 of the fifth embodiment, a lower substrate 71 having a first metal layer 72 on the lower surface side is provided below the intermediate substrate 74 on which the planar coil layer 75 is formed. Has been placed. Further, an upper substrate 76 having a second metal layer 77 on the upper surface side is disposed on the upper side of the intermediate substrate 74.

  Further, the outer surface of the planar coil layer 75 is formed so as to penetrate from the upper substrate 76 to the lower substrate 71, and is connected to the first and second metal layers 72 and 77, and the outer surface of the planar coil layer 75. A plurality of outer penetrating metal portions 78A arranged so as to surround are formed. Further, inside the planar coil layer 75, an inner through metal portion 78B is formed so as to penetrate from the upper substrate 76 to the lower substrate 71 and connected to the first and second metal layers 72 and 77. Has been.

  As described above, in the inductor built-in component 70 according to the fifth embodiment, the magnetic flux leakage preventing metal (first and second metal layers 72 and 77, outer and inner penetrating metal portions 78 </ b> A) is formed between the upper and lower sides, the outer side, and the inner side of the planar coil layer 75. 78B). When a current is passed through the planar coil layer 75 via the external connection terminal 79, the magnetic flux generated around the planar coil layer 75 is collected in the second metal layer 77. Since the copper layer portion of the second metal layer 77 is paramagnetic, magnetic flux is transmitted through the copper layer.

  The magnetic flux collected in the upper second metal layer 77 is guided to the outer through metal portion 78A outside the planar coil layer 75, and is guided into the first metal layer 72 through the outer through metal portion 78A. Further, the magnetic flux guided to the first metal layer 72 is guided to the inner through metal portion 78B, and returns to the second metal layer 77 again through the internal through metal portion 78B.

  Thus, according to the inductor built-in component 70 of the fifth embodiment, the magnetic flux generated by the current flowing through the planar coil layer 75 is generated by the first and second metal layers 72 and 77, the outer penetrating metal portion 78A and the inner penetrating metal. It is confined by the portion 77B, and leakage of the magnetic flux to the outside is prevented. Therefore, the number of linkages between the planar coil layer 75 and the magnetic flux can be increased, and the inductance of the planar coil layer 75 can be increased.

  In the inductor built-in component 70, the inductor element is configured by forming the thin planar coil layer 75 on the intermediate substrate 74, so that the inductor built-in component 70 can be thinned.

  As a result, the semiconductor chip and the inductor built-in component 70 constituting the power supply circuit can be easily mounted on the same substrate. As a result, since the power supply wiring can be set to the shortest, a voltage drop of the power supply wiring can be prevented, and a stable operation of the semiconductor chip can be realized.

  In the above description, the case where one planar coil layer 75 is formed is illustrated, but the present embodiment is not limited to this, and the planar coil layer 75 includes n layers (n is an integer of 2 or more). It is good also as a laminated flat coil. In this case, it is possible to form a laminated planar coil by laminating a plurality of intermediate substrates on which the planar coil layers 75 are formed and interconnecting the ends of each planar coil layer 75 with vias or the like. Alternatively, a laminated planar coil may be produced by alternately forming a plurality of insulating layers and planar coil layers on the intermediate substrate on which the planar coil layer 75 is formed by a build-up method or the like.

  10, 20, 40, 50, 70 ... Inductor built-in components, 11, 21 ... Substrate, 11a, 22a, 23a, 24a, 25a ... Via holes, 12, 31, 32, 33, 34, 35, 42, 58, 75 ... Planar coil layer, 13, 22, 23, 24, 25, 26, 47, 57, 59 ... Insulating layer, 14, 37, 48, 60 ... Magnetic flux leakage prevention metal cap, 15, 36, 46, 56, 79 ... External Connection terminals, 41, 51 ... wiring boards, 41A, 51A ... circuit boards, 52a, 52b ... metal pillars, 43, 53 ... DC / DC converters, 44, 54 ... semiconductor chips, 45, 55 ... passive components (capacitors), 57a, 57b ... opening, 71 ... lower substrate, 72 ... first metal layer, 74 ... intermediate substrate, 76 ... upper substrate, 77 ... second metal layer, 78A ... outer through metal portion, 78B ... inner through metal portion Plating power-supply material ... 90, TH ... through-hole.

Claims (2)

An intermediate substrate on which a planar coil layer is formed;
A lower substrate disposed under the intermediate substrate and including a first metal layer on a lower surface side;
An upper substrate disposed on the intermediate substrate and provided with a second metal layer on the upper surface side;
A plurality of outer penetrating metal portions formed so as to penetrate from the upper substrate to the lower substrate, connected to the first and second metal layers, and disposed so as to surround the outside of the planar coil;
An inner penetrating metal portion formed through the upper substrate to the lower substrate, connected to the first and second metal layers, and disposed inside the planar coil,
The inductor built-in component, wherein the first metal layer, the second metal layer, the outer penetrating metal portion, and the inner penetrating metal portion are formed of a magnetic flux leakage preventing metal.   The inductor built-in component according to claim 1, wherein the magnetic flux leakage preventing metal is made of iron, cobalt, nickel, or an alloy thereof.

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