JP2014116457A - Method of manufacturing inductor, inductor, and composite circuit element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable mass production of a thin inductor having a high rated current value.SOLUTION: An inductor 1 includes a first layer 10, a second layer 20, and a third layer 30. The first layer 10 contains a ferrite sintered body 11. The second layer 20 is formed on the first layer 10 and includes a coil 22 and a protective layer 23 in which a composite material of a metal magnetic body and a thermoset resin is filled between windings of the coil 22 by screen printing. The third layer 30 contains a ferrite sintered body 31 and is bonded to the second layer 20.

Description

  The present invention relates to an inductor having a configuration in which a winding pattern (coil) made of a conductive material is formed on a magnetic substrate. The present invention also relates to a method for manufacturing the inductor, and a composite circuit element in which the inductor is integrated with a semiconductor element.

  As this type of inductor, a composite magnetic body made of a magnetic powder and a thermosetting resin is sandwiched between a pair of magnetic substrates, and a coil is embedded in the composite magnetic body is known ( For example, see Patent Document 1). In order to manufacture such an inductor, first, a coil sandwiched between uncured composite magnetic sheets is further sandwiched between a pair of magnetic substrates. By heating and pressing this laminate, the composite magnetic material is filled between the windings and cured.

JP 2001-176728 A

  With the downsizing of electronic devices using inductors, there is a demand for thin inductors that have a high rated current value and have a dimension in the stacking direction of 0.5 mm or less. The manufacturing method described above requires a step of sandwiching the coil with a pair of composite magnetic sheets, so that it is difficult to reduce the dimension in the stacking direction, that is, to reduce the thickness, and is not suitable for mass production.

  Accordingly, an object of the present invention is to provide a technique that enables mass production of a thin inductor having a high rated current value.

In order to achieve the above object, a first aspect of the present invention is a method for manufacturing an inductor,
Forming at least one coil on the first layer including the ferrite sintered body;
Filling a metal magnetic material and a thermosetting resin composite material between the windings of the at least one coil to form a second layer by screen printing;
Adhering a third layer containing a ferrite sintered body to the second layer.

  According to such a method, magnetic saturation is less likely to occur by filling a metal magnetic material and a thermosetting resin composite material between the windings of the coil, and the rated current value can be increased. Further, since the filling process is performed by screen printing, the second layer can be formed very thin. Furthermore, since a filling process can be performed on a large number of coils at a time, it is suitable for mass production.

  After the second layer is thermally cured, the third layer may be bonded to the second layer with an adhesive containing a metal magnetic material. Alternatively, the third layer may be adhered to the second layer by bringing the third layer into contact with the second layer and then thermosetting the second layer. .

  In the former case, high adhesive strength of the third layer to the second layer can be ensured. In the latter case, since the adhesion between the coil included in the second layer and the ferrite sintered body included in the third layer is increased, the inductance can be improved. Further, since the adhesive layer is unnecessary, the inductor can be further reduced in thickness.

  A method may be used in which the at least one coil is formed by forming a winding pattern on the ferrite sintered body of the first layer by electrolytic plating. Alternatively, the at least one coil is formed by bonding a metal foil to the ferrite sintered body of the first layer, printing a resist having a shape corresponding to a winding pattern on the metal foil, and etching the resist. It is good also as a method formed by removing the said metal foil which is not covered, and removing the said resist.

  In the former case, since the adhesion between the coil contained in the second layer and the ferrite sintered body contained in the first layer is increased, the inductance can be improved. Further, since the adhesive layer is unnecessary, the inductor can be further reduced in thickness. In the latter case, the coil can be formed by a relatively inexpensive process, which contributes to a reduction in manufacturing cost. Further, since the coil is formed of a metal foil, the inductor can be further reduced in thickness.

  After forming a plurality of coils on the first layer and bonding the third layer to the second layer, the plurality of coils are separated from each other by cutting, so that each of the at least one coil It is good also as a method of obtaining the several inductor containing. This method is suitable for mass production of inductors.

An inductor manufactured by such a method can be thinned to keep the dimension in the stacking direction to 0.5 mm or less while having a high rated current value. Therefore, in order to achieve the above object, a second aspect that the present invention can take is an inductor,
A first layer including a ferrite sintered body;
A second layer formed on the first layer, including a coil, and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between windings of the coil by screen printing;
And a third layer including a ferrite sintered body bonded to the second layer.

Along with the downsizing of electronic equipment, there is an increasing demand for downsizing of the composite circuit elements to be mounted. Since the above inductor has a high rated current value and can be thinned, the composite circuit element can be miniaturized to meet the demand. Therefore, in order to achieve the above object, a third aspect that the present invention can take is a composite circuit element,
A semiconductor element having a first electrode;
An inductor integrated with the semiconductor element;
The inductor is
A first layer including a ferrite sintered body;
A second layer formed on the first layer, including a coil, and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between windings of the coil by screen printing;
A third layer comprising a ferrite sintered body adhered to the second layer;
The second layer is provided on the opposite side of the first layer from the side on which the second layer is formed, and includes a second electrode electrically connected to the coil and the first electrode.

In order to achieve the above object, a fourth aspect of the present invention is a method for manufacturing an inductor,
Forming a first coil on the first layer including the ferrite sintered body;
A step of filling a metal magnetic material and a thermosetting resin composite material between the windings of the first coil by screen printing to form a second layer;
Forming a second coil on the third layer including the ferrite sintered body;
Filling a metal magnetic material and a thermosetting resin composite material between the windings of the second coil by screen printing to form a fourth layer;
Bonding the thermally cured second layer and the fourth layer and electrically connecting the first coil and the second coil.

  According to such a method, in addition to the same effects as those described for the first aspect, the number of turns of the coil per unit area in the second layer and the fourth layer can be reduced. For example, even if the number of turns of the first coil and the second coil is halved, the number of turns of the coil as a whole can be maintained by electrically connecting the two. Since the winding density of the coil can be lowered, a large area of the core portion can be secured and the inductance can be improved. Further, since the wire diameter (cross-sectional area) of the coil can be increased, the resistance to the current flowing through the coil is reduced, and heat generation can be suppressed.

In a manner similar to the second aspect, in order to achieve the above object, a fifth aspect that the present invention can take is an inductor,
A first layer including a ferrite sintered body;
A second coil formed on the first layer, including a first coil and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between the windings of the first coil by screen printing; Layers,
A third layer including a ferrite sintered body;
A fourth coil formed on the third layer, including a second coil, and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between the windings of the second coil by screen printing; With layers,
The second layer and the fourth layer are bonded together, and the second layer coil and the fourth layer coil are electrically connected.

Similarly to the third aspect, in order to achieve the above object, the sixth aspect that the present invention can take is a composite circuit element,
A semiconductor element having a first electrode;
An inductor integrated with the semiconductor element;
The inductor is
A first layer including a ferrite sintered body;
A second coil formed on the first layer, including a first coil and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between the windings of the first coil by screen printing; Layers,
A third layer including a ferrite sintered body;
A fourth coil formed on the third layer, including a second coil, and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between the windings of the second coil by screen printing; Layers,
A second electrode provided on the opposite side of the first layer from the side on which the second layer is formed, and electrically connected to the coil and the first electrode;
The second layer and the fourth layer are bonded together, and the second layer coil and the fourth layer coil are electrically connected.

  According to the present invention, it is possible to mass-produce a thin inductor having a high rated current value.

It is a perspective view which shows the structure of the inductor which concerns on the 1st Embodiment of this invention. It is a figure which shows the manufacturing method of the inductor of FIG. It is a figure which shows the manufacturing method of the inductor of FIG. It is a figure which shows the manufacturing method of the inductor of FIG. It is a figure which shows the method of manufacturing simultaneously several inductors shown in FIG. It is a graph which shows the direct current | flow superimposition characteristic of the inductor shown in FIG. It is a perspective view which shows the structure of a composite circuit element provided with the inductor shown in FIG. It is sectional drawing which shows the structure of the inductor which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the inductor which concerns on the 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In each drawing used in the following description, the scale is appropriately changed to make each member a recognizable size.

  FIG. 1A is a perspective view showing an external appearance of the inductor 1 according to the first embodiment of the present invention as viewed from above. The inductor 1 includes a lower substrate 10, a coil formation layer 20, and an upper substrate 30. A coil forming layer 20 is formed between the lower substrate 10 and the upper substrate 30 each having a rectangular plate shape. The lower substrate 10, the coil forming layer 20, and the upper substrate 30 correspond to the first layer, the second layer, and the third layer of the present invention, respectively.

  FIG. 1B is a perspective view showing an appearance of the inductor 1 as viewed from below. Electrode patterns 16 a and 16 b made of copper foil are formed on the lower surface 10 b of the lower substrate 10.

  FIG. 1C shows a state in which the upper substrate 30 is removed from the inductor 1 and the coil forming layer 20 is exposed. On the upper surface 10a of the lower substrate 10, a coil 22 made of a copper foil as a metal foil is formed. Both ends of the winding pattern are terminals 22a and 22b, which are electrically connected to the electrode patterns 16a and 16b, respectively.

  The coil 22 is covered with a protective layer 23. The protective layer 23 is obtained by thermosetting a composite material containing magnetic metal powder as a metal magnetic material and a thermosetting resin. The composite material is filled between the windings of the coil 22.

  Next, a method for manufacturing the inductor 1 will be described with reference to FIGS.

  First, as shown in FIGS. 2A to 2C, copper foils 12a and 12b are bonded to the upper surface 11a and the lower surface 11b of the ferrite sintered body 11 as a magnetic body, respectively. Adhesion is performed with an adhesive containing magnetic metal powder. FIG. 2B shows a cross section taken along line IIB-IIB in FIGS. 2A and 2C. Reference numerals 13a and 13b denote adhesive layers formed between the copper foils 12a and 12b and the ferrite sintered body 11, respectively.

  Next, as shown in FIGS. 2D to 2F, the insertion hole 14 is formed by a known method. FIG. 2E shows a cross section taken along line IIE-IIE in FIGS. 2D and 2F. The insertion hole 14 extends along the lamination direction of the ferrite sintered body 11, the copper foils 12a and 12b, and the adhesive layers 13a and 13b, and is formed so as to pass through them.

  Next, as shown in FIGS. 2G to 2I, the insertion hole 14 is filled with the copper paste 15 by a known method. (H) in FIG. 2 shows a cross section taken along line IIH-IIH in (g) and (i) of FIG. By this step, the copper foils 12a and 12b are electrically connected.

  Next, as shown in FIGS. 3A to 3C, a resist 21a having a shape corresponding to the coil winding pattern is formed on the copper foil 12a, and the electrode patterns 16a and 16b are formed on the copper foil 12b. A resist 21b having a corresponding shape is formed. FIG. 3B shows a cross section taken along line IIIB-IIIB in FIGS. 3A and 3C. The resists 21a and 21b are each formed by printing.

  Next, as shown in FIGS. 3D to 3F, the copper foils 12a and 12b are etched by a known method. FIG. 3E shows a cross section taken along line IIIE-IIIE in FIGS. 3D and 3F. The copper foils 12a and 12b are removed except for the portions where the resists 21a and 21b are formed, and the adhesive layers 13a and 13b are exposed at the portions.

  Next, as shown in FIGS. 3G to 3I, the resists 21a and 21b are removed. (H) of FIG. 3 shows a cross section taken along line IIIH-IIIH in (g) and (i) of FIG. By this step, the lower substrate 10 including the ferrite sintered body 11 is obtained.

  The upper surface of the adhesive layer 13 a becomes the upper surface 10 a of the lower substrate 10. A coil 22 having a predetermined winding pattern shape is formed on the upper surface 10a by removing the resist 21a. The lower surface of the adhesive layer 13 b becomes the lower surface 10 b of the lower substrate 10. On the lower surface 10b, electrode patterns 16a and 16b having a predetermined shape are formed by removing the resist 21b. The coil terminals 22a and 22b are electrically connected to the electrode patterns 16a and 16b through the copper paste 15, respectively.

  Next, as shown in FIGS. 4A to 4C, a protective layer 23 covering the coil 22 is formed. Specifically, the composite material described above is applied so as to cover the coil by screen printing, and is filled between the windings of the coil 22. Subsequently, the composite material is subjected to a thermosetting treatment, and the coil forming layer 20 including the coil 22 and the protective layer 23 is obtained. FIG. 4B shows a cross section taken along line IVB-IVB in FIGS. 4A and 4C.

  Next, as shown in FIGS. 4D to 4F, the upper substrate 30 is bonded to the coil forming layer 20. The upper substrate 30 is obtained by forming an adhesive layer 32 on a ferrite sintered body 31. The adhesive layer 32 is an adhesive containing magnetic metal powder. FIG. 4E shows a cross section taken along line IVE-IVE in FIGS. 4D and 4F.

  Through the above steps, the inductor 1 including the lower substrate 10 including the ferrite sintered body 11, the coil forming layer 20 including the coil 22 and the protective layer 23, and the upper substrate 30 including the ferrite sintered body 31 is obtained. The coil forming layer 20 is formed on the lower substrate 10, and the upper substrate 30 is bonded to the coil forming layer 20. The protective layer 23 is formed by filling a composite material of a magnetic metal and a thermosetting resin between the windings of the coil 22 by screen printing.

  Next, a method for obtaining a plurality of inductors 1 having the above configuration will be described with reference to FIG.

  First, the copper foils 12a and 12b are bonded to the ferrite sintered body 11 having an area where a necessary number of coils 22 can be formed by the steps described with reference to FIGS. Subsequently, through the steps described with reference to FIGS. 2D to 2F, the number of insertion holes 14 corresponding to the number of terminals 22a and 22b of the required number of coils 22 is formed. Subsequently, the insertion hole 14 is filled with the copper paste 15 by the process described with reference to FIGS.

  Next, the resist 21a having a shape corresponding to the winding pattern is formed on the copper foil 12a by the number of coils 22 required by the steps described with reference to FIGS. A resist 21b having a shape corresponding to the electrode patterns 16a and 16b is formed on the foil 12b. Subsequently, by the steps described with reference to FIGS. 3D to 3F, the copper foils 12a and 12b are removed by etching except the portions where the resists 21a and 21b are formed. Subsequently, the resists 21a and 21b are removed by the steps described with reference to FIGS.

  Next, the composite material described above is applied by screen printing so as to cover all of the necessary number of coils 22 formed on the lower substrate 10 by the process described with reference to FIGS. Applied. Subsequently, the composite material is subjected to a thermosetting treatment, and the coil forming layer 20 is formed.

  Next, the upper substrate 30 having an area capable of covering all of the formed coils 22 is bonded to the coil forming layer 20 by the steps described with reference to FIGS. . Subsequently, the coils 22 are separated from each other by being cut along a one-dot chain line shown in FIG. 5 by a known method. Thereby, a plurality of inductors 1 each having at least one coil 22 can be obtained at a time.

  FIG. 6 is a graph showing the measurement result of the DC superposition characteristics of the inductor 1 obtained by the above manufacturing method. As a comparative example, the characteristics of a conventional inductor using a composite material of ferrite powder and resin for the protective layer of the coil are also shown.

  As the current flowing through the coil increases, the inductance of the inductor decreases due to magnetic saturation. The broken line shown in the graph indicates a value in which the initial inductance is reduced by 30%, and the current value that reaches this value is the rated current. That is, a larger amount of current can flow through the inductor having the characteristic that the inductance is difficult to decrease.

  From the measurement results shown in FIG. 6, it can be seen that the inductor 1 according to the present embodiment has a characteristic that magnetic saturation is less likely to occur than the inductor according to the comparative example. The current value at which the initial inductance of the inductor 1 is reduced by 30% reaches 1.5 times that of the inductor according to the comparative example. It can be seen that by using a composite material of magnetic metal powder and thermoplastic resin for the protective layer of the coil 22, a significant improvement in the rated current was obtained.

  In this embodiment, since the protective layer 23 is formed by filling the composite material between the windings of the coil 22 by screen printing, the coil forming layer 20 can be formed very thin. Therefore, it is possible to obtain a thin inductor with a dimension in the stacking direction of 0.5 mm or less while having a high rated current value as described above. Furthermore, since the coil 22 itself is also formed of copper foil, it contributes to the thinning of the inductor.

  Further, since the screen printing is used for filling the composite material between the windings of the coil 22, as described with reference to FIG. It is suitable for mass production.

  The inductor 1 according to the present embodiment can be used in a part of a circuit that converts energy, such as a switching power supply or a DC / DC converter. Specifically, as shown in FIG. 7A, a semiconductor element 60 having a switching function and a voltage conversion function and the inductor 1 are integrated to constitute a composite circuit element 100. FIG. 7B is a perspective view showing a state where the semiconductor element 60 and the inductor 1 are separated.

  The semiconductor element 60 is provided with contact electrodes 60c and 60d as the first electrode of the present invention so as to extend from the upper surface 60a to the side surface 60b. These can be formed by applying and baking silver paste. On the other hand, as shown in FIG. 1B, the lower surface 10b of the lower substrate 10 of the inductor 1, that is, the side opposite to the side on which the coil forming layer 20 is formed is the second electrode of the present invention. Electrode patterns 16a and 16b are provided. Integration of the semiconductor element 60 and the inductor 1 is performed so that the contact electrodes 60b and 60c are electrically connected to the electrode patterns 16a and 16b, respectively.

  The composite circuit element 100 is formed on the circuit board by electrically connecting various terminals (not shown) provided on the lower surface of the semiconductor element 60 to contact terminals provided on the circuit board (not shown). Implemented. By soldering the contact electrodes 60c and 60d provided on the side surface of the semiconductor element 60 to the wiring pattern formed on the circuit board, the inductor 1 and the circuit formed on the circuit board are electrically connected. . The contact electrodes 60c and 60d may be extended to the lower surface of the semiconductor element and electrically connected to the circuit together with the various terminals.

  Along with the downsizing of electronic equipment, there is an increasing demand for downsizing of the composite circuit elements to be mounted. As described above, the inductor 1 according to the present embodiment can be reduced in thickness while having a high rated current value. Therefore, the composite circuit element 100 can be reduced in size to meet the demand.

  Next, an inductor 1A according to a second embodiment of the present invention will be described with reference to FIG. The inductor 1A is different from the inductor 1 according to the first embodiment in that the lower substrate 10A as the first layer and the upper substrate 30A as the third layer do not include the adhesive layers 13a, 13b, and 32. .

  In the present embodiment, first of all, the electrode patterns 16a and 16b and the coil 22 other than the formation positions of the surface of the ferrite sintered body 11 are covered with a mask, and electroplating is performed, whereby an electrode pattern 16a made of copper foil, 16 b and the coil 22 are formed on the ferrite sintered body 11. The formation of the insertion hole 14 and the filling of the copper paste 15 are performed in the same manner as the method for manufacturing the inductor 1.

  In this embodiment, the upper substrate 30 </ b> A made only of the ferrite sintered body 31 is brought into contact with the protective layer 23 before thermosetting the composite material filled between the windings of the coil 22. By performing the thermosetting process in this state, the upper substrate 30 </ b> A is bonded to the coil forming layer 20.

  According to such a structure, since the adhesive layers 13a and 31 are not interposed between the coil 22 and the ferrite sintered bodies 11 and 31, the value of inductance can be increased by increasing the adhesion between the two. . Further, since the adhesive layers 13a, 13b, and 31 do not exist, it is possible to further reduce the thickness.

  The method for forming the coil 22 of the inductor 1 according to the first embodiment, that is, the copper foils 12a and 12b are bonded to the ferrite sintered body 11, and the electrode patterns 16a and 16b and the coil 22 are formed by etching. The method has a cost advantage.

  The inductor 1A thus obtained can be integrated with the semiconductor element 60 shown in FIG. 7 to constitute a composite circuit element.

  Next, an inductor 1B according to a third embodiment of the present invention will be described with reference to FIG. The inductor 1B is different from the inductors 1 and 1A according to the above-described embodiment in that the inductor 1B includes two coil forming layers 20 and 40. That is, the inductor 1B includes the lower substrate 10, the lower coil forming layer 20A, the upper substrate 30, and the upper coil forming layer 40. The lower substrate 10, the lower coil forming layer 20A, the upper substrate 30, and the upper coil forming layer 40 correspond to the first layer, the second layer, the third layer, and the fourth layer in the present invention, respectively.

  Similarly to the inductor 1 according to the first embodiment, the lower coil 22A as the first coil of the present invention is formed on the lower substrate 10 including the ferrite sintered body 11. Similarly to the inductor 1 according to the first embodiment, the protective layer 23A is formed by filling the composite material of magnetic metal powder and thermosetting resin between the windings of the lower coil 22A and performing thermosetting treatment. Is done.

  On the other hand, the copper foil adhered on the ferrite sintered body 31 via the adhesive layer 32 is etched in the same manner as the inductor 1 according to the first embodiment, whereby the second coil of the present invention. The upper coil 42 is formed on the upper substrate 30. Similarly to the inductor 1 according to the first embodiment, the protective layer 43 is formed by filling the composite material of magnetic metal powder and thermosetting resin between the windings of the upper coil 42 and performing thermosetting treatment. Is done.

  Next, the adhesive layer 50 is formed on the lower coil forming layer 20A. The adhesive layer 50 is made of an adhesive containing magnetic metal powder. Subsequently, an insertion hole is formed in a part of the adhesive layer 50, and the copper paste 51 is filled in the part.

  Next, the lower coil forming layer 20 </ b> A and the upper coil forming layer 40 are bonded via the adhesive layer 50. At this time, the connection portion 22 c of the lower coil 22 and the connection portion 44 c of the upper coil 42, and the connection portion 22 d of the lower coil 22 and the connection portion 42 d of the upper coil are electrically connected via the copper paste 51. As a result, the electrode pattern 16a is wound from the outside to the inside via the terminal 22a of the coil 22, is connected from the connecting portion 22c to the connecting portion 42c, is wound outward from the connecting portion 42c, and reaches the connecting portion 42d. A coil having a series of paths connected from the portion 42d to the electrode pattern 16b via the connecting portion 22d is formed.

  According to such a configuration, the number of turns of the coil per unit area for each coil forming layer can be reduced. For example, the number of turns of the coil 22 of the inductor 1A shown in FIG. On the other hand, the number of turns of the lower coil 22A and the upper coil 42 of the inductor 1B is 2, but the coil of 4 turns as a whole is realized by electrically connecting the lower coil 22A and the upper coil 42. Yes. Since the winding density of the coil can be reduced, a large area can be secured in the area surrounded by the broken line in the center of FIG. 9, that is, the core part. Therefore, the inductance value can be increased with the same number of turns. Further, since the wire diameter of the coil, that is, the cross-sectional area of the copper foil pattern can be increased, the resistance to the current flowing through the coil is reduced, and heat generation can be suppressed.

  The inductor 1B thus obtained can be integrated with the semiconductor element 60 shown in FIG. 7 to constitute a composite circuit element.

  The above embodiment is for facilitating understanding of the present invention, and does not limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

  In the inductor 1 according to the first embodiment, the adhesive layers 13a and 13b may be omitted. That is, the electrode patterns 16a and 16b and the coil 22 may be directly formed on the ferrite sintered body 11 using electrolytic plating.

  In the inductor 1 according to the first embodiment, the adhesive layer 31 may be omitted. That is, the protective layer 23 and the ferrite sintered body 31 may be bonded by bringing the ferrite sintered body 31 into direct contact with the uncured composite material covering the coil 22 and then performing a thermosetting process.

  In the inductor 1A according to the second embodiment, the adhesive layers 13a and 13b in the inductor 1 may be provided. That is, the electrode patterns 16a and 16b and the coil 22 may be formed by bonding the copper foil to the ferrite sintered body 11 via the adhesive layers 13a and 13b and performing an etching process.

  In the inductor 1A according to the second embodiment, the adhesive layer 32 in the inductor 1 may be provided. That is, the upper substrate 30 having the adhesive layer 32 may be bonded to the coil forming layer 20 after the composite material covering the coil 22 is thermally cured.

  In the inductor 1B according to the third embodiment, the adhesive layers 13a, 13b, and 32 may be omitted. That is, the electrode patterns 16 a and 16 b and the lower coil 22 </ b> A may be directly formed on the ferrite sintered body 11 and the upper coil 42 may be directly formed on the ferrite sintered body 31 using electrolytic plating.

  In the inductor 1B according to the third embodiment, the adhesive layer 50 may be omitted. That is, the uncured composite material covering the lower coil 22A and the uncured composite material covering the upper coil 42 are brought into direct contact with each other, and then a thermosetting process is performed, whereby the lower coil forming layer 20A and the upper coil forming layer are formed. It is good also as a structure to which 40 is adhere | attached. In this case, the copper paste 51 is unnecessary.

  In the inductor 1B according to the third embodiment, a core made of a ferrite sintered body may be arranged in the core portion surrounded by a broken line in FIG.

  In all the embodiments, the shape and number of the electrode patterns 16a and 16b and the coil 22 (the lower coil 22A and the upper coil 42) can be appropriately determined according to the specifications of the inductor 1 (1A and 1B).

  The expressions “upper” and “lower” in the above description are merely used for convenience in the description with reference to the drawings, and are not intended to limit the direction in use of the product. “Upper” and “lower” can be paraphrased as the side far from the electrode patterns 16a and 16b and the side near, respectively.

  1, 1A, 1B: inductor, 10, 10A: lower substrate, 11: ferrite sintered body, 12a: copper foil, 13a: adhesive layer, 16a, 16b: electrode pattern, 20: coil forming layer, 20A: lower coil forming Layer, 21a: resist, 22: coil, 22A: lower coil, 23, 23A: protective layer, 30, 30A: upper substrate, 31: ferrite sintered body, 32: adhesive layer, 40: upper coil forming layer, 42: Upper coil, 43: protective layer, 50: adhesive layer, 60: semiconductor element, 60b, 60c: contact electrode, 100: composite circuit element

Claims (11)

Forming at least one coil on the first layer including the ferrite sintered body;
Filling a metal magnetic material and a thermosetting resin composite material between the windings of the at least one coil to form a second layer by screen printing;
Adhering a third layer containing a ferrite sintered body to the second layer.   The manufacturing method according to claim 1, wherein after the second layer is thermally cured, the third layer is bonded to the second layer with an adhesive containing a metal magnetic material.   The third layer is bonded to the second layer by bringing the third layer into contact with the second layer and then thermally curing the second layer. Manufacturing method.   The manufacturing method according to any one of claims 1 to 3, wherein the at least one coil is formed by forming a winding pattern on the ferrite sintered body of the first layer by electrolytic plating. . The at least one coil comprises:
Bonding a metal foil to the ferrite sintered body of the first layer,
Print a resist corresponding to the winding pattern on the metal foil,
Removing the metal foil not covered with the resist by etching;
The manufacturing method according to claim 1, wherein the manufacturing method is formed by removing the resist. Forming a plurality of coils on the first layer;
4. The inductor according to claim 1, wherein after the third layer is bonded to the second layer, the plurality of coils are separated by cutting to obtain a plurality of inductors each including at least one coil. 5. The manufacturing method according to claim 1. Forming a first coil on the first layer including the ferrite sintered body;
A step of filling a metal magnetic material and a thermosetting resin composite material between the windings of the first coil by screen printing to form a second layer;
Forming a second coil on the third layer including the ferrite sintered body;
Filling a metal magnetic material and a thermosetting resin composite material between the windings of the second coil by screen printing to form a fourth layer;
A method of manufacturing an inductor, comprising: bonding the second layer and the fourth layer which are thermally cured, and electrically connecting the first coil and the second coil. A first layer including a ferrite sintered body;
A second layer formed on the first layer, including a coil, and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between windings of the coil by screen printing;
An inductor comprising a ferrite sintered body bonded to the second layer. A first layer including a ferrite sintered body;
A second coil formed on the first layer, including a first coil and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between the windings of the first coil by screen printing; Layers,
A third layer including a ferrite sintered body;
A fourth coil formed on the third layer, including a second coil, and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between the windings of the second coil by screen printing; With layers,
The inductor, wherein the second layer and the fourth layer are bonded together, and the coil of the second layer and the coil of the fourth layer are electrically connected. A semiconductor element having a first electrode;
An inductor integrated with the semiconductor element;
The inductor is
A first layer including a ferrite sintered body;
A second layer formed on the first layer, including a coil, and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between windings of the coil by screen printing;
A third layer comprising a ferrite sintered body adhered to the second layer;
A composite circuit element, comprising: a second electrode that is provided on a side of the first layer opposite to the side on which the second layer is formed and is electrically connected to the coil and the first electrode. A semiconductor element having a first electrode;
An inductor integrated with the semiconductor element;
The inductor is
A first layer including a ferrite sintered body;
A second coil formed on the first layer, including a first coil and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between the windings of the first coil by screen printing; Layers,
A third layer including a ferrite sintered body;
A fourth coil formed on the third layer, including a second coil, and a protective layer in which a composite material of a metal magnetic body and a thermosetting resin is filled between the windings of the second coil by screen printing; Layers,
A second electrode provided on the opposite side of the first layer from the side on which the second layer is formed, and electrically connected to the coil and the first electrode;
The composite circuit element, wherein the second layer and the fourth layer are bonded together, and the coil of the second layer and the coil of the fourth layer are electrically connected.

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