Inductor element and method for manufacturing inductor element

Abstract

To provide an inductor element having such a structure as to reduce warpage.SOLUTION: An inductor element 11 includes a supporting body 13 having a main surface having a first area 13b and a second area 13c surrounding the first area 13b, a first resin body 15 arranged in the first area 13b of the main surface, and an inductor 17 positioned on the main surface of the supporting body 13. The first resin body 15 includes a first soft magnetic material layer 21 and a second soft magnetic material layer 23 which are arranged in the first area 13b of the main surface. The inductor 17 is positioned between the first soft magnetic material layer 21 and the second soft magnetic material layer 23. The first soft magnetic material layer 21 includes a first insulating resin body 21a and a plurality of first magnetic material bodies 21b and 21c surrounded by the first insulating resin body 21a. The second soft magnetic material layer 23 includes a second insulating resin body 23a, and a plurality of second magnetic bodies 23b and 23c surrounded by the second insulating resin body 23a. A second resin body 29A exists between the first soft magnetic material layer 21 and the second soft magnetic material layer 23.SELECTED DRAWING: Figure 17

Description

[Technical field]

[0001] The present invention relates to an inductor element and a method for making an inductor element. [Background technology]

[0002] Patent Document 1 discloses a wafer level package (WLP). Specifically, Patent Document 1 discloses a resin multilayer device having a capacitor and an inductor and / or a balun, and the resin multilayer device is used in, for example, a high-frequency circuit of a wireless communication device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-268304 A Summary of the Invention [Problem to be solved by the invention]

[0004] Forming a multi-layer or thick resin layer on a support such as a semiconductor substrate can cause warping of the wafer in the manufacturing process, and can also cause warping of the semiconductor chip as the semiconductor chip is thinned.

[0005] An object of the present invention is to provide an inductance element having a structure capable of reducing warping, and a method for manufacturing an inductance element capable of reducing warping. [Means for solving the problem]

[0006] The inductor element according to a first aspect of the present invention comprises a support having a main surface including a first area and a second area surrounding the first area, a first resin body arranged in the first area of ​​the main surface, and an inductor located on the main surface of the support, the first resin body including a first soft magnetic layer and a second soft magnetic layer arranged in the first area of ​​the main surface, the inductor being located between the first soft magnetic layer and the second soft magnetic layer, the first soft magnetic layer including a first insulating resin body and a plurality of first magnetic bodies surrounded by the first insulating resin body, the second soft magnetic layer including a second insulating resin body and a plurality of second magnetic bodies surrounded by the second insulating resin body. The inductor includes a conductive layer having a pattern configured to generate inductance and extending along the main surface, the conductive layer having a first portion located in the first area and a second portion located in the second area, and the inductor element further includes an outer electrode located on the second portion. The inductor element further comprises an inner end electrode located on the first portion, the first portion of the conductive layer located on the first soft magnetic layer, the conductive layer further comprises a third portion located between the first area and the second area of ​​the main surface, the third portion of the conductive layer crossing the boundary between the first area and the second area to connect the first and second portions. The inductor element further comprises a second resin body provided on the first and second areas and covering a side surface of the outer end electrode, the inner end electrode having a lower portion covered within the first resin body and an upper portion located outside the first resin body. The second resin body covers the upper portion of the outer end electrode, and the second resin body is arranged so as to be sandwiched between the first soft magnetic layer and the second soft magnetic layer in the first area.

[0007] A method for fabricating an inductor element according to a second aspect of the present invention includes: preparing a substrate including a main surface having a first area and a second area surrounding the first area; forming a first soft magnetic layer on the first area of ​​the substrate; forming a conductive layer having a first portion located on the first area and a second portion located on the second area and extending across the first area and the second area of ​​the substrate after forming the first soft magnetic layer; forming an outer electrode on the second portion of the conductive layer; and forming a second soft magnetic layer on the first area of ​​the substrate after forming the conductive layer, wherein the first soft magnetic layer includes a first insulating resin body and a plurality of first soft magnetic bodies surrounded by the first insulating resin body, and the second soft magnetic layer includes a second insulating resin body and a plurality of second soft magnetic bodies surrounded by the second insulating resin body. The method further includes forming a second resin body covering side surfaces of the outer electrode in the first area and the second area. Effect of the Invention

[0008] According to the above aspects, there are provided an inductance element having a structure capable of reducing warping, and a method for manufacturing an inductance element capable of reducing warping. [Brief description of the drawings]

[0009] [Figure 1] Fig. 1(a) is a schematic diagram of an inductor element according to a first embodiment. Fig. 1(b) is a schematic diagram of the inductor element according to the first embodiment in a cross section taken along line Ib-Ib in Fig. 1(a). [Diagram 2] FIG. 2 is a diagram showing a cross section of the conductive layer and the first soft magnetic layer of the inductor element according to the first embodiment taken along line Ib-Ib in FIG. 1(a). [Diagram 3] FIG. 3 is a diagram showing a cross section of the conductive layers and soft magnetic layers of the inductor element according to the first embodiment taken along line Ib-Ib in FIG. [Figure 4]Fig. 4(a) is a plan view showing one element segment in the manufacturing process of the element according to Fig. 1(a), and Fig. 4(b) is a drawing showing a cross section corresponding to line Ib-Ib in Fig. 1(a) in the manufacturing process. [Diagram 5] Fig. 5(a) is a plan view showing one element segment in the manufacturing process of the element according to Fig. 1(a), and Fig. 5(b) is a drawing showing a cross section corresponding to line Ib-Ib in Fig. 1(a) in the manufacturing process. [Figure 6] Fig. 6(a) is a plan view showing one element segment in the manufacturing process of the element according to Fig. 1(a), and Fig. 6(b) is a drawing showing a cross section corresponding to line Ib-Ib in Fig. 1(a) in the manufacturing process. [Figure 7] Fig. 7(a) is a plan view showing one element segment in the manufacturing process of the element according to Fig. 1(a), and Fig. 7(b) is a drawing showing a cross section corresponding to line Ib-Ib in Fig. 1(a) in the manufacturing process. [Figure 8] Fig. 8(a) is a plan view showing one element segment in the manufacturing process of the element according to Fig. 1(a), and Fig. 8(b) is a drawing showing a cross section corresponding to line Ib-Ib in Fig. 1(a) in the manufacturing process. [Figure 9] Fig. 9(a) is a plan view showing one element segment in the manufacturing process of the element according to Fig. 1(a), and Fig. 9(b) is a drawing showing a cross section corresponding to line Ib-Ib in Fig. 1(a) in the manufacturing process. [Figure 10] Fig. 10(a) is a plan view showing one element segment in the manufacturing process of the element according to Fig. 1(a), and Fig. 10(b) is a drawing showing a cross section corresponding to line Ib-Ib in Fig. 1(a) in the manufacturing process. [Figure 11] Fig. 11(a) is a plan view showing one element segment in the manufacturing process of the element according to Fig. 1(a), and Fig. 11(b) is a drawing showing a cross section corresponding to line Ib-Ib in Fig. 1(a) in the manufacturing process. [Figure 12]Fig. 12(a) is a plan view showing one element segment in the manufacturing process of the element according to Fig. 1(a), and Fig. 12(b) is a drawing showing a cross section corresponding to line Ib-Ib in Fig. 1(a) in the manufacturing process. [Figure 13] Fig. 13(a) is a plan view showing one element segment in the manufacturing process of the element according to Fig. 1(a), and Fig. 13(b) is a drawing showing a cross section corresponding to line Ib-Ib in Fig. 1(a) in the manufacturing process. [Figure 14] Fig. 14(a) is a schematic diagram of an inductor element according to a second embodiment. Fig. 14(b) is a schematic diagram of an inductor element according to a second embodiment, in a cross section taken along line Ib-Ib in Fig. 14(a). [Figure 15] 5A to 5C are cross-sectional views illustrating a manufacturing process for the inductor element according to the second embodiment. [Figure 16] 5A to 5C are cross-sectional views illustrating a manufacturing process for the inductor element according to the second embodiment. [Figure 17] Fig. 17(a) is a schematic diagram of an inductor element according to a third embodiment. Fig. 17(b) is a schematic diagram of an inductor element according to a third embodiment, in a cross section taken along line Ib-Ib in Fig. 17(a). [Figure 18] 10A to 10C are cross-sectional views illustrating a manufacturing process for the inductor element according to the third embodiment. [Figure 19] 10A to 10C are cross-sectional views illustrating a manufacturing process for the inductor element according to the third embodiment. [Figure 20] 10A to 10C are cross-sectional views illustrating a manufacturing process for the inductor element according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, each embodiment for carrying out the present invention will be described with reference to the drawings. The same or similar parts are denoted by the same or similar reference numerals, and duplicated explanations will be omitted. Note that, in order to facilitate understanding, various plan views and cross-sectional views may be drawn with a different dimensional ratio from that of the actual product in the horizontal plane and cross section. In addition, in the plan views and cross-sectional views, in order to facilitate understanding and illustration, the dimensional ratios may be different from each other.

[0011] [First embodiment] Fig. 1(a) is a schematic diagram of an inductor element according to a first embodiment. Fig. 1(b) is a schematic diagram of the inductor element according to the first embodiment in a cross section taken along line Ib-Ib in Fig. 1(a) (a cross section bent 90° at a turning point Ax).

[0012] The inductor element 11 includes a support 13 , a first resin body 15 , and an inductor 17 .

[0013] The support 13 has a main surface 13a and a back surface 13d, and the main surface 13a is located on the opposite side to the main surface 13a. The main surface 13a has a first area 13b and a second area 13c, and the second area 13c surrounds the first area. The first resin body 15 is located within the first area 13b of the main surface 13a. The inductor 17 is made of a conductor and is located on the main surface 13a of the support 13. The first resin body 15 can include at least a first soft magnetic layer 21 and a second soft magnetic layer 23, and the first soft magnetic layer 21 and the second soft magnetic layer 23 are arranged to overlap at least partially within the first area 13b of the main surface 13a.

[0014] The inductor 17 is provided between the first soft magnetic layer 21 and the second soft magnetic layer 23. The first soft magnetic layer 21 includes a first insulating resin body 21a and a plurality of first magnetic bodies 21b, 21c surrounded by the first insulating resin body 21a, and the first magnetic bodies 21b, 21c are distributed by the first insulating resin body 21a. The second soft magnetic layer 23 includes a second insulating resin body 23a and a plurality of second magnetic bodies 23b, 23c surrounded by the second insulating resin body 23a, and the second magnetic bodies 23b, 23c are distributed by the second insulating resin body 23a.

[0015] According to the inductor element 11, the first soft magnetic layer 21 and the second soft magnetic layer 23 sandwich the inductor 17 from both sides and provide the periphery of the inductor 17 with a magnetic permeability greater than that of the air. The insulating resin bodies (21a, 23a) in each of the first soft magnetic layer 21 and the second soft magnetic layer 23 enable a magnetic body (e.g., magnetic pieces, magnetic grains, magnetic powder, or magnetic filler) to be dispersed and arranged within the resin body, thereby reducing non-uniformity in the magnetic permeability in each of the first soft magnetic layer 21 and the second soft magnetic layer 23. In addition, each of the first soft magnetic layer 21 and the second soft magnetic layer 23 forms an insulating region (21a, 23b) around the inductor 17. Furthermore, the density of the magnetic bodies (21b, 23b) in each of the first soft magnetic layer 21 and the second soft magnetic layer 23 can be a value that does not cause a short circuit of the inductor 17 due to the stringing of magnetic bodies in the soft magnetic layer. The upper limit of the size of the magnetic bodies (21b, 23b) can be a value that does not cause a short circuit of the inductor 17 via the magnetic bodies in the soft magnetic layer, and can be, for example, 100 micrometers or less. Increasing the thickness of the first soft magnetic layer 21 makes it possible to relax the upper limit of the size of the magnetic bodies (21b, 23b).

[0016] The insulating resin body (21a, 23a) may be made of a cured resin that can be supplied onto the substrate by, for example, a dispenser, and such a resin may contain a heat curing agent and, if necessary, may contain an ultraviolet curing agent instead of or in addition to the heat curing agent.

[0017] The first magnetic bodies 21b, 21c and the second magnetic bodies 23b, 23c may include a magnetic material. Specifically, the first magnetic bodies 21b, 21c and the second magnetic bodies 23b, 23c may include a magnetic metal element or a magnetic oxide such as ferrite.

[0018] The support 13 may include, for example, a semiconductor region 14a and an insulating inorganic or organic insulator region 14b located on the semiconductor region 14a. The semiconductor region 14a may be, for example, silicon, silicon carbide, germanium, and silicon germanium. In the first embodiment, the main surface 13a of the support 13 may be provided by the insulator region 14b. The semiconductor region 14a may include, for example, one or more semiconductor devices 14c.

[0019] The inductor 17 includes a conductive layer 18 extending along the major surface 13a, the conductive layer 18 having a pattern configured to generate an inductance. The conductive layer 18 may include, for example, copper. According to the inductor element 11, the inductance is generated by the pattern of the conductive layer 18 to provide, for example, a two-dimensional inductor 17. The inductance of the inductor 17 is provided by an inductor main portion 18a of the conductive layer 18. As shown in FIG. As shown in FIG. 1A, the inductor main portion 18a has, for example, a two-dimensional spiral shape. The conductive layer 18 has a first portion 18b located on the first area 13b and a second portion 18c located on the second area 13c.

[0020] The inductor element 11 may further include an outer electrode 25, which is located in the second area 13c (on the second portion 18c) in the first embodiment. The outer electrode 25 is also separated from the first resin body 15. When the outer electrode 25 is located on the second portion 18c of the conductive layer 18, the first soft magnetic layer 21 and the first soft magnetic layer 23 are not processed to form the outer electrode 25.

[0021] The inductor element 11 may further include an inner end electrode 27, which in the first embodiment is located on the first portion 18b of the conductive layer 18. The first portion 18b of the conductive layer 18 is located on the first soft magnetic layer 21 and below the second soft magnetic layer 23.

[0022] FIG. 2 is a diagram showing a cross section of the conductive layer 18 and the first soft magnetic layer 21 of the inductor element 11 according to the present embodiment taken along the line Ib-Ib.

[0023] In FIG. 2, for ease of understanding, the conductive layer 18 and the first soft magnetic layer 21 provided on the support 13 are depicted. The first soft magnetic layer 21 includes a skirt 22a and a central portion 22b surrounded by the skirt 22a in the first area 13b of the main surface 13a. The skirt 22a is inclined relative to the upper surface 22c of the central portion 22b, which allows the thickness of the first soft magnetic layer 21 to be gradually thinner at the skirt 22a. The side surface 22s of the skirt 22a is smoothly inclined relative to the upper surface 22c of the central portion 22b, and a change in the thickness of the first soft magnetic layer 21 is caused at the skirt 22a in order to place the first soft magnetic layer 21 in the first area 13b. The upper surface 22c of the central portion 22b is substantially flat relative to the side surface 22s of the skirt 22a. 2, the size of upper surface 22c of central portion 22b can be 5 or more times or 10 or more times the size of skirt portion 22a extending from central portion 22b along main surface 13a. With such a size ratio, central portion 22b is provided with a size appropriate for disposing conductive layer 18 of inductor element 11.

[0024] 1(a), 1(b) and 2, in the first embodiment, the inductor main part 18a of the conductive layer 18 can be disposed within the upper surface 22c of the central part 22b. The side surface 22s of the bottom part 22a does not include an abrupt step, such as a steep cliff shape, that exceeds the thickness of the conductive layer 18, and the first magnetic bodies 21b and 21c in the first soft magnetic body layer 21 are preferably covered by the first insulating resin body 21a without substantially appearing on the upper surface of the first soft magnetic body layer 21.

[0025] The conductive layer 18 further includes a third portion 18d located on the first area 13b and the second area 13c, and the third portion 18d connects the first portion 18b and the second portion 18c across the boundary between the first area 13b and the second area 13c. The outer end electrode 25 and the inner end electrode 27 are connected to the outer end 20b and the inner end 20a, respectively.

[0026] According to the inductor element 11, the combination of the spirally wound conductive layer 18 and the first soft magnetic layer 21 and the second soft magnetic layer 23 sandwiching the inductor main portion 18a of the conductive layer 18 can provide a large inductance.

[0027] Specifically, the conductive layer 18 has a first portion 18b (see FIG. 2) located within the first area 13b and a second portion 18c (see FIG. 2) located within the second area 13c. The pattern of the conductive layer 18 also has an inner end 20a (see FIG. 1) located on the first area 13b and an outer end 20b (see FIG. 1) located on the second area 13c.

[0028] In the first embodiment, the inductor main part 18a has a spiral shape, and the conductive layer 18 extends from the inner end 20a of the spiral shape in either a clockwise or counterclockwise direction so as to surround the inner end 20a. The inductor main part 18a has a plurality of winding parts that wind around the inner end 20a. The plurality of winding parts in the conductive layer 18 have an innermost inner part and an outermost outer part in the spiral shape. At least one of the first soft magnetic layer 21 and the second soft magnetic layer 23 is located between the winding parts and contributes to the confinement of magnetic flux. The conductive layer 18 has one or more intermediate winding parts between the inner part and the outer part.

[0029] FIG. 3 is a drawing showing the conductive layer 18 and the soft magnetic layers 21 and 23 of the inductor element according to the present embodiment in a cross section taken along the line Ib-Ib. In FIG. 2, for ease of understanding, the conductive layer 18, the first soft magnetic layer 21, the second soft magnetic layer 23, and the inner end electrode 27 provided on the support 13 are depicted. The second soft magnetic layer 23 includes a skirt 24a and a central portion 24b surrounded by the skirt 24a in the first area 13b of the main surface 13a. The skirt 24a is inclined relative to the upper surface 24c of the central portion 24b, which allows the thickness of the second soft magnetic layer 23 to be gradually thinner at the skirt 24a. The side surface 24s of the skirt 24a is smoothly inclined relative to the upper surface 24c of the central portion 24b, and a change in thickness of the second soft magnetic layer 23 is caused at the skirt 24a in order to place the second soft magnetic layer 23 in the first area 13b. 3, the size of the top surface 22c of the central portion 24b can be 5 or more times or 10 or more times the size of the skirt portion 24a extending from the central portion 24b along the surface of the first soft magnetic layer 21. With such a size ratio, the central portion 24b is provided with a size appropriate for covering the conductive layer 18 of the inductor element 11.

[0030] The second soft magnetic layer 23 has an opening 23h, and the opening 23h is located on the first portion 18b of the conductive layer 18. The opening 23h reaches the first portion 18b of the conductive layer 18. The inner electrode 27 extends through the opening 23h of the second soft magnetic layer 23 and reaches the conductive layer 18 so that the second soft magnetic layer 23 covers a part of the side surface 27s of the inner electrode 27. Specifically, since the second soft magnetic layer 23 is formed after the formation of the inner electrode 27, the opening 23h of the second soft magnetic layer 23 is shaped to match the shape of the inner electrode 27. Therefore, the size of the opening 23h is matched to the cross-sectional shape of the conductive layer 18, and the lower part of the side surface 27s of the inner electrode 27 is in close contact with the side surface 23s of the opening 23h. The upper part of the side surface 27s of the inner electrode 27 is not covered by the second soft magnetic layer 23. According to the inductor element 11, the inner end electrode 27 is electrically connected to the conductive layer 18 through the opening 23h of the second soft magnetic layer 23.

[0031] On the other hand, since the outer electrode 25 is separated from the first resin body 15 , the outer electrode 25 can be formed without processing the first resin body 15 .

[0032] 1, the inductor element 11 may further include a second resin body 29, which is provided on the first area 13b and the second area 13c, and more specifically, may be provided on the entire surface of the support 13. The second resin body 29 covers the first resin body 15. The second resin body 29 covers the side surface 25s of the outer end electrode 25 and also covers an upper portion of the side surface 27s of the inner end electrode 27. The second resin body 29 may be a coating body including a coating resin such as epoxy or polyimide. The upper surfaces of the outer end electrode 25 and the inner end electrode 27 are not covered by the second resin body 29 and are exposed.

[0033] According to the inductor element 11, the second resin body 29 can be provided on the first area 13b and the second area 13c of the main surface 13a while avoiding the first resin body 15 including the soft magnetic material layer being provided on the second area 13c. It is possible to cover the entire body 15 and protect the first resin body 15.

[0034] In the first embodiment, the inductor element 11 may include connection electrodes 30 such as solder balls (eg, AuSn) located on the upper ends of the outer and inner electrodes 25 and 27, respectively.

[0035] Figures 4(a) to 13(b) are drawings showing the main steps in a method for fabricating an inductor element according to this embodiment. In the following description, a wafer-sized substrate is used for fabricating inductor element 11 instead of support 13, but the description will be given with reference to support 13 for simplicity. Therefore, each of Figures 4(a) to 13(b) shows one element section. Each of Figures 4(a) to 13(a) shows a plan view in the fabrication process of the element according to Figure 1(a), and each of Figures 4(b) to 13(b) shows a cross-sectional view in the fabrication process of the element according to Figure 1(b).

[0036] 4(a) and 4(b), a support 13 (substrate) including a main surface 13a is prepared. The main surface 13a has a first area 13b and a second area. After the preparation, a first soft magnetic layer 21 is formed on the first area 13b of the support 13. The first soft magnetic layer 21 is formed according to the following procedure.

[0037] First, an uncured first soft magnetic resin liquid 31 for the first soft magnetic layer 21 is prepared, and the first soft magnetic resin liquid 31 is placed within a limited area 13b of the support 13. This placement can be achieved by various methods, such as dropping, printing, or applying the first soft magnetic resin liquid 31 within the first area 13b. In the first embodiment, the first soft magnetic resin liquid 31 is placed within the first area 13b using a dispenser 33a.

[0038] 5(a) and 5(b), after the first soft magnetic resin liquid 31 is placed in the first area 13b, the first soft magnetic resin liquid 31 is then cured to obtain the first soft magnetic layer 21. In the first embodiment, a heat treatment is used for the curing. Specifically, the support 13 including the first soft magnetic resin liquid 31 is placed in a heat treatment device 33b (e.g., a baking device), and the first soft magnetic layer 21 is generated from the first soft magnetic resin liquid 31 by heat treatment.

[0039] 6(a) and 6(b), after forming the first soft magnetic layer 21, a conductive layer 18 having a pattern for the inductor 17 is formed. The conductive layer 18 has a first portion 18b located on the first area 13b of the support 13 and a second portion 18c located on the second area 13c of the support 13. The conductive layer 18 also extends across the boundary between the first area 13b and the second area 13c. The patterning of the conductive layer 18 is performed, for example, by deposition and patterning of a conductive film. The deposition of the conductive film is performed, for example, by depositing a metal, for example, titanium, by a sputtering method. The patterning can be performed, for example, by photolithography and etching, or a lift-off method can be used.

[0040] Referring to FIG. 7(a) and FIG. 7(b), in the first embodiment, the outer end electrode 25 and the inner end electrode 27 are formed on the conductive layer 18. Although the outer end electrode 25 and the inner end electrode 27 can be formed separately in each process, here, the outer end electrode 25 and the inner end electrode 27 are formed together in a single process. The outer end electrode 25 and the inner end electrode 27 are formed on the first portion 18b and the second portion 18b of the conductive layer 18, respectively. The outer end electrode 25 and the inner end electrode 27 are formed, for example, by electrolytic plating. Specifically, after forming a seed layer SD on the entire surface of the support 13, a resist film having a pattern for the outer end electrode 25 and the inner end electrode 27 is formed. The support 13 and the resist film are immersed in an electrolytic plating solution, and metal deposition is caused while a current is passed through them. In the first embodiment, the copper post PT is formed by electrolytic plating.

[0041] 8(a) and 8(b), after forming the outer electrode 25 and the inner electrode 27, the second soft magnetic layer 23 is formed in the first area 13b of the support 13. The second soft magnetic layer 23 is formed in the following procedure.

[0042] First, an uncured first soft magnetic resin liquid 35 for the second soft magnetic layer 23 is prepared, and the second soft magnetic resin liquid 35 is placed only in the first area 13b of the support 13. This placement can be achieved by various methods, such as dropping, printing, or applying the second soft magnetic resin liquid 35 in the first area 13b. In the first embodiment, the second soft magnetic resin liquid 35 is placed in the first area 13b using a dispenser 33c.

[0043] 9(a) and 9(b), after the second soft magnetic resin liquid 35 is placed in the first area 13b, the second soft magnetic resin liquid 35 is then cured to obtain the second soft magnetic layer 23. In the first embodiment, a heat treatment is used for the curing. Specifically, the support 13 including the second soft magnetic resin liquid 35 is placed in a heat treatment device 33d (e.g., a baking device), and the second soft magnetic layer 23 is generated from the second soft magnetic resin liquid 35 by heat treatment.

[0044] 10(a) and 10(b), after the first resin body 15 is formed, a thick sealing film 37 is formed on the entire surface of the support 13. The sealing film 37 may be, for example, an epoxy resin. The sealing film 37 may be formed by, for example, spin coating. The sealing film 37 is hardened by heat treatment. In the following description, the hardened sealing film is denoted by the reference symbol "37". The thick sealing film 37 has a thickness that allows the outer end electrode 25 and the inner end electrode 27 to be embedded therein.

[0045] 11(a) and 11(b), the thick sealing film 37 is polished to expose the upper ends of the outer electrode 25 and the inner electrode 27. By polishing, the thick sealing film 37 becomes the sealing body 39. The sealing body 39 can have a thickness of, for example, about 300 micrometers or less. The first soft magnetic layer 21 can have a thickness of, for example, about 100 micrometers or less. The second soft magnetic layer 23 can have a thickness of, for example, about 100 micrometers or less. The first soft magnetic layer 21 can have a thickness of, for example, about 40 micrometers or more. The second soft magnetic layer 23 can have a thickness of, for example, about 40 micrometers or more. The second soft magnetic layer 23 makes it possible to space the inductor from the sealing body 39.

[0046] 12(a) and 12(b), after forming the encapsulant 39, electrodes 41 are formed on the exposed upper ends of the outer end electrodes 25 and the inner end electrodes 27. The electrodes 41 may include, for example, solder balls.

[0047] 13(a) and 13(b), after forming the encapsulant 39, the back surface of the support 13 (substrate) is polished to provide the support 13 with a desired thickness. The side surfaces of the outer end electrode 25 and the inner end electrode 27 are covered with the encapsulant 39. The wafer used in the manufacturing process may have a thickness of, for example, about 700 micrometers. The support 13 may have a thickness of, for example, about 200 micrometers or less.

[0048] According to this manufacturing method, the first soft magnetic layer 21 is formed in the first area 13b, and then the conductive layer 18 of the inductor 17 is formed, and the second soft magnetic layer 23 is formed in the first area 13b, after the conductive layer 18 of the inductor 17 is formed. At least the inductor main part 18a of the conductive layer 18 is provided between the first soft magnetic layer 21 and the second soft magnetic layer 23. The outer electrode 25 is separated from the first soft magnetic layer 21 and the second soft magnetic layer 23. The area where the first soft magnetic layer 21 and the second soft magnetic layer 23 are formed is smaller than the entire surface of the main surface 13a. Therefore, warping of the support 13 (substrate, wafer) is reduced.

[0049] The outer electrode 25 is formed without processing the first soft magnetic layer 21 and the second soft magnetic layer 23. According to this manufacturing method, the inner electrode 27 is formed without processing the first soft magnetic layer 21 and the second soft magnetic layer 23.

[0050] As described above, according to the present embodiment, an inductance element having a structure capable of reducing warping, and a method for manufacturing an inductance element capable of reducing warping are provided.

[0051] [Second embodiment] Next, an inductor element according to a second embodiment will be described with reference to FIG. Fig. 14(a) is a diagram showing an inductor element according to a second embodiment. Fig. 14(b) is a diagram showing an inductor element according to a second embodiment in a cross section taken along line Ib-Ib in Fig. 14(a). In Fig. 14, the same components as those in Fig. 1 are given the same reference numerals as those in Fig. 1, and therefore repeated explanations will be omitted.

[0052] In the inductor element of the second embodiment, the conductive layer 18 constituting the inductor 17 is provided between the first soft magnetic layer 21 and the second soft magnetic layer 23, as in the first embodiment. However, in the second embodiment, the first soft magnetic layer 21 and the second soft magnetic layer 23 are not provided over substantially the entire first area 13b as in the first embodiment, but the first soft magnetic layer 21 and the second soft magnetic layer 23 are selectively (concentratedly) provided only in the region where the conductive layer 18 constituting the inductor 17 is provided. In other words, even in the first area 13b, the first soft magnetic layer 21 and the second soft magnetic layer 23 are not formed in the region where the inner end electrode 27 is provided, and the second resin body 29 is formed directly on the conductive layer 18. Other points may be the same as those of the first embodiment.

[0053] According to the structure of the inductor element of the second embodiment, the proportion of the soft magnetic layer in the first area 13b can be further reduced compared to the first embodiment, thereby further reducing the possibility of warping of the support 13.

[0054] The inner end electrode 27 is formed so that the height of its upper end is higher (for example, about 50 μm) than the height of the second soft magnetic layer 23. Thereby, as described later, when the second resin body 29 is polished based on the top of the inner end electrode 27, the second soft magnetic layer 23 is not excavated by polishing, and the top of the inner end electrode 27 can be exposed to form a terminal of the inductor element.

[0055] Next, the main steps in the method for fabricating the inductor element of the second embodiment will be described with reference to Fig. 15 and Fig. 16. Fig. 15 and Fig. 16 are cross-sectional views showing the method for fabricating the inductor element. The transitions in the plan view are substantially the same as those in the first embodiment, and therefore are not shown.

[0056] 15(a), a first soft magnetic layer 21 is formed on a first area 13b of a main surface 13a of a support 13 by a method similar to that of the first embodiment. At this time, the first soft magnetic layer 21 is selectively formed in a region where a conductive layer 18 is to be formed thereafter, and is not formed in a region where an inner electrode 27 is to be formed.

[0057] After the first soft magnetic layer 21 is hardened, the conductive layers 18 (18b, 18c) are formed on the main surface 13a (on the surfaces of the insulating regions 14b) and on the first soft magnetic layer 21, as shown in FIG. 15(b).

[0058] 15(c), the outer electrode 25 and the inner electrode 27 are formed on the conductive layer 18. Although not shown in FIG. 15(c), a seed layer SD is formed in the area where the outer electrode 25 and the inner electrode 27 are to be formed, and then copper posts are deposited by electrolytic plating to form the outer electrode 25 and the inner electrode 27. The height h1 of the outer electrode 25 and the inner electrode 27 from the first soft magnetic layer 21 is set to, for example, 200 μm or more so that the height is higher than the surface of the second resin body 29 to be formed later.

[0059] 15(d), a second soft magnetic layer 23 is selectively formed in the region of the first area 13b where the first soft magnetic layer 21 is formed. The formation method may be the same as that of the first embodiment (see FIGS. 9 and 10).

[0060] 16(a), a sealing film made of epoxy resin or the like is deposited on the entire surface of the support 13 to such an extent that the second soft magnetic layer 23 is buried therein. Then, a heat treatment is performed to harden the sealing film, thereby forming a second resin body 29.

[0061] Thereafter, the second resin body 29 is polished to perform a flattening process on the surface of the second resin body 29. The height h2 of the second resin body 29 from the surface of the second soft magnetic layer 23 is preferably at least twice the diameter of the filler contained in the second resin body 29, for example, about 50 μm.

[0062] After the second resin body 29 has been polished and planarized, electrodes 30 (solder balls or the like) are formed on the upper ends of the outer end electrodes 25 and the inner end electrodes 27 exposed on the surface of the second resin body 29 .

[0063] According to this manufacturing method, the area where the first soft magnetic layer 21 and the second soft magnetic layer 23 are formed is smaller than the entire main surface 13a, so that warping of the support 13 (substrate, wafer) is reduced. In the second embodiment, the area where the first soft magnetic layer 21 and the second soft magnetic layer 23 are formed is limited to the area where the inductor 17 is formed (the area where the conductive layer 18 is formed), and is not formed in the area where the inner end electrode 27 is formed, so that warping of the support 13 can be further reduced.

[0064] [Third embodiment] Next, with reference to FIG. 17, an inductor element according to a third embodiment will be described. Fig. 17(a) is a diagram showing an inductor element according to a third embodiment. Fig. 17(b) is a diagram showing an inductor element according to a third embodiment in a cross section taken along line Ib-Ib in Fig. 17(a). In Fig. 17, the same components as those in Fig. 1 are given the same reference numerals as those in Fig. 1, and therefore repeated explanations will be omitted.

[0065] In the inductor element of the third embodiment, the inductor 17 (conductive layer 18) is provided between the first soft magnetic layer 21 and the second soft magnetic layer 23, as in the first embodiment. However, the inductor element of the third embodiment has an internal resin body 29A, which is a part of the second resin body 29, between the first soft magnetic layer 21 and the second soft magnetic layer 23 in the first area 13b, and in this respect, is different from the inductor element of the first embodiment in which the first soft magnetic layer 21 and the second soft magnetic layer 23 are directly in contact with each other above and below. In order to deposit the internal resin body 29A between the first soft magnetic layer 21 and the second soft magnetic layer 23, in the example shown in FIG. 17, the first soft magnetic layer 21 may include an underlying soft magnetic layer 21A arranged on the upper surface of the support 13 and an additional soft magnetic layer 21B additionally arranged along the outer peripheral upper surface of the underlying soft magnetic layer 21A. Other points may be the same as those of the first embodiment. The second resin body 29 is also formed in the second area 13c as an outer resin body 29B, similarly to the first embodiment. The outer resin body 29B may be formed directly above the conductive layer 18 in the second area 13c. In the third embodiment, the second resin body 29 is composed of the inner resin body 29A and the outer resin body 29.

[0066] Next, main steps in a method for producing the inductor element of the third embodiment will be described with reference to Figures 18 to 20. Figures 18 to 20 are cross-sectional views showing a method for producing the inductor element.

[0067] First, as shown in FIG. 18(a), an underlying soft magnetic layer 21A as a part of the first soft magnetic layer 21 is formed on the first area 13b of the main surface 13a of the support 13 by the same method as in the first embodiment.

[0068] After the underlying soft magnetic layer 21A is hardened, the conductive layers 18 (18b, 18c) are formed on the main surface 13a and on the underlying soft magnetic layer 21A, as shown in FIG. 18(b).

[0069] Next, as shown in Fig. 18(c), the outer end electrode 25 and the inner end electrode 27 are formed on the conductive layer 18. Although not shown in Fig. 18(c), a seed layer SD is formed in the region where the outer end electrode 25 and the inner end electrode 27 are to be formed, and then copper posts are deposited by using an electrolytic plating method to form the outer end electrode 25 and the inner end electrode 27. The height h3 of the outer end electrode 25 and the inner end electrode 27 from the underlying soft magnetic material layer 21A is set to, for example, 200 µm or more so that the height is higher than the surface of the second resin body 29 to be formed later.

[0070] 18(d), the additional soft magnetic layer 21B is deposited along the outer periphery of the underlying soft magnetic layer 21A and cured by thermal curing. The thickness h4 of the additional soft magnetic layer 21B is preferably set to be at least twice the diameter of the filler contained in the resin deposited in the subsequent process, and for example, h4 is preferably set to about 50 μm.

[0071] 19(a), an internal resin body 29A made of epoxy resin or the like is deposited on the entire main surface 13a of the support 13, for example, to a height equal to that of the upper surface of the additional soft magnetic layer 21B, and then thermally cured. The internal resin body 29A is deposited not only in the second area 13c, but also on the upper surface of the first soft magnetic layer 21 in the first area 13b. That is, in this third embodiment, the internal resin body 29A is formed after the first soft magnetic layer 21 is formed and before the second soft magnetic layer 23 is formed. In this respect, the first embodiment differs from the first embodiment in that the resin body 29 is formed after the second soft magnetic layer 23 is formed.

[0072] 19(b), the second soft magnetic layer 23 is selectively deposited and cured above the resin body 29A and the additional soft magnetic layer 21B in the first area 13b. As a result, in the inductor element of the third embodiment, a structure is obtained in which an internal resin body 29A made of epoxy resin or the like is interposed between the first soft magnetic layer 21 and the second soft magnetic layer 23. With this structure, the ratio of the first soft magnetic layer 21 and the second soft magnetic layer 23 in the first area 13b can be made smaller than that of the structure of the first embodiment, and the possibility of warping of the support 13 can be reduced.

[0073] 20(a), a sealing film made of epoxy resin or the like is deposited on the entire surface of the support 13 to such an extent that the second soft magnetic layer 23 is buried therein. Then, the sealing film is hardened by performing a heat treatment to form the outer resin body 29B. In the second area 13c, the already deposited inner resin body 29A and a newly deposited resin body are combined to form the outer resin body 29B.

[0074] 20(b), the outer resin body 29B is polished to flatten the surface of the outer resin body 29B. The height h5 of the outer resin body 29B from the surface of the second soft magnetic layer 23 is preferably at least twice the diameter of the filler contained in the second resin body 29, for example, about 50 μm.

[0075] After the outer resin body 29B has been polished and planarized, electrodes 25X and 27X (solder balls, etc.) are formed on the upper ends of the outer end electrode 25 and the inner end electrode 27 exposed on the surface of the outer resin body 29B, as shown in FIG. 20(c).

[0076] As described above, according to the structure and manufacturing method of the third embodiment, the proportion of the first soft magnetic layer 21 and the second soft magnetic layer 23 in the first area 13b is reduced by the amount of the resin body 29A interposed between them, so that warping of the support 13 (substrate, wafer) is further reduced compared to the first embodiment.

[0077] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and scope of the present invention, all of which are included in the technical concept of the present invention. [Explanation of symbols]

[0078] REFERENCE SIGNS LIST 11 inductor element, 13 support, 13a main surface, 13b area, 13b first area, 13c second area, 13d back surface, 14a semiconductor region, 14b insulator region, 14c semiconductor device, 15 resin body, 17 inductor, 18 conductive layer, 18a main inductor portion, 18b first portion, 18c second portion, 18d third portion, 20a inner end, 20b outer end, 21 first soft magnetic layer, 21a first insulating resin body, 21b, 21c first magnetic body, 22a bottom portion, 22b central portion, 22c upper surface, 2 2s...side surface, 23...second soft magnetic layer, 23a...second insulating resin body, 23b, 23c...second magnetic body, 23h...opening, 24a...bottom portion, 24b...center portion, 24c...upper surface, 24s...side surface, 25...outer end electrode, 25X...electrode, 25s...side surface, 27...inner end electrode, 27X Electrode, 27s, side surface, 29, second resin body, 29A, inner resin body, 29B, outer resin body, 31, second soft magnetic body, 33a, 33c, dispenser, 33b, 33d, heat treatment device, 35, second soft magnetic body resin liquid, 37, sealing film, 39, sealing body, 30, 41, electrode

Claims

1. A support having a main surface including a first area and a second area surrounding the first area; a first resin body disposed within the first area of ​​the main surface; an inductor located on the major surface of the support; Equipped with the first resin body includes a first soft magnetic layer and a second soft magnetic layer disposed in the first area of ​​the main surface, the inductor is located between the first soft magnetic layer and the second soft magnetic layer, the first soft magnetic layer includes a first insulating resin body and a plurality of first magnetic bodies surrounded by the first insulating resin body, the second soft magnetic layer includes a second insulating resin body and a plurality of second magnetic bodies surrounded by the second insulating resin body, the inductor includes a conductive layer having a pattern configured to generate an inductance and extending along the major surface; the conductive layer has a first portion located within the first area and a second portion located within the second area; further comprising an outer end electrode located on the second portion; further comprising an inner end electrode located on the first portion; the first portion of the conductive layer overlies the first soft magnetic layer; the conductive layer further includes a third portion located between the first area and the second area of ​​the main surface; the third portion of the conductive layer connects the first portion and the second portion across the boundary between the first area and the second area, a second resin body provided on the first area and the second area and covering a side surface of the outer electrode; the inner end electrode has a lower portion covered within the first resin body and an upper portion located outside the first resin body, the second resin body covers the upper portion of the outer electrode, An inductor element, wherein the second resin body is arranged so as to be sandwiched between the first soft magnetic layer and the second soft magnetic layer in the first area.

2. The inductor element according to claim 1 , wherein the first soft magnetic layer further comprises an underlying soft magnetic layer disposed on the upper surface of the support, and an additional soft magnetic layer disposed along an outer peripheral upper surface of the underlying soft magnetic layer.

3. 1. A method of forming an inductor element, comprising the steps of: providing a substrate including a major surface having a first area and a second area surrounding the first area; forming a first soft magnetic layer on the first area of ​​the substrate; forming a conductive layer having a first portion located above the first area and a second portion located above the second area and extending across the first area and the second area of ​​the substrate after forming the first soft magnetic layer; forming an outer electrode on the second portion of the conductive layer; forming a second soft magnetic layer on the first area of ​​the substrate after forming the conductive layer; Equipped with the first soft magnetic layer includes a first insulating resin body and a plurality of first soft magnetic bodies surrounded by the first insulating resin body; the second soft magnetic layer includes a second insulating resin body and a plurality of second soft magnetic bodies surrounded by the second insulating resin body, The method for producing an inductor element further includes forming a second resin body in the first area and the second area to cover side surfaces of the outer electrode.

4. The method for producing an inductor element according to claim 3 , wherein the second resin body is formed after the second soft magnetic layer is formed.

5. The method for producing an inductor element according to claim 3 , wherein the second resin body is formed after the first soft magnetic layer is formed and before the second soft magnetic layer is formed.

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