The present disclosure relates to a circuit component and a semiconductor device.
Conventionally, circuit components are incorporated in various electronic devices such as industrial equipment, home appliances, information terminals, and automotive equipment. Examples of such circuit components include magnetic components such as inductors and transformers. An example of a conventional inductor component is disclosed in Patent Document 1, for example. The inductor component disclosed in Patent Document 1 has insulating layers and conductor patterns. The insulating layers and the conductor patterns are alternately stacked. The conductor patterns have a spiral shape, for example, and a magnetic field is generated when a current flows through the conductor patterns.
For improved performance of electronic devices incorporating circuit components, the circuit components are required to have improved characteristics. For example, when the circuit component is a magnetic component, the inductance value needs to be improved. Some magnetic components use a rod-shaped or annular magnetic core (iron core) to improve the inductance value. However, using a magnetic core generates core loss (iron loss) due to the magnetic properties of the magnetic core.
In light of the above circumstances, an object of the present disclosure is to provide a circuit component capable of reducing iron loss while improving the inductance value. Another object of the present disclosure is to provide a semiconductor device incorporating such a circuit component.
A circuit component provided according to a first aspect of the present disclosure includes: a resin composite body including a resin material containing a plurality of magnetic particles; and a conductor formed on a surface of the resin composite body, and is characterized in that the plurality of magnetic particles are dispersed in the resin material.
A semiconductor device, which is provided according to a second aspect of the present disclosure, includes a circuit component provided according to the first aspect and a transistor electrically connected to the circuit component.
The circuit component according to the present disclosure achieves both improvement of the inductance value and reduction of iron loss. The semiconductor device according to the present disclosure can improve the performance, because it incorporates a circuit component that achieves both improvement of the inductance value and reduction of iron loss.
Preferred embodiments of a circuit component and a semiconductor device according to the present disclosure are described below with reference to the drawings. In the following description, the same or similar elements are denoted by the same reference signs, and descriptions thereof are omitted.
A circuit component A1 according to a first embodiment is described below with reference to
For convenience of description, reference will be made to three mutually orthogonal directions, i.e., the x direction, the y direction and the z direction. The z direction is the thickness direction of the circuit component A1. The x direction is the horizontal direction in a plan view (see
The circuit component A1 is a magnetic component that produces inductance from the current flowing in the conductor 3. The present embodiment describes an example in which the circuit component A1 is an inductor. The size of the circuit component A1 may vary. In one example, each of the dimension in the x direction and the dimension in the y direction is about 1 to 10 mm.
The support substrate 1 supports the resin composite body 2 and the conductor 3. The support substrate 1 is rectangular in plan view, for example. The support substrate 1 is an insulating substrate, such as a silicon substrate, a glass epoxy substrate, a resin substrate, or a ceramic substrate.
The resin composite body 2 is made of a resin material 20 containing a plurality of magnetic particles 21. The volume content of the magnetic particles 21 in the resin composite body 2 is not less than 60% and not more than 90%, for example. The relative magnetic permeability of the resin composite body 2, i.e., the magnetic permeability of the composite of the resin material 20 and the magnetic particles 21 is 10 or greater, for example. The relative magnetic permeability of the resin composite body 2 is not limited to 10 or greater. However, the relative magnetic permeability of 10 or greater is preferable for making the circuit component A1 have an inductance suitable for practical use. The resin composite body 2 is rectangular in plan view. The resin material 20 is, for example, a thermosetting resin, such as epoxy resin or phenolic resin. The resin composite body 2 is formed on the support substrate 1. The plurality of magnetic particles 21 include a plurality of first particles 22 and a plurality of second particles 23.
As shown in
The first cores 221 are made of metallic magnetic powder. As the metallic magnetic powder, materials containing a metallic element that exhibits ferromagnetism by itself are preferably used, examples of which include materials containing one or more elements selected from Fe, Co and Ni (i.e., containing Fe or Co or Ni, or their alloys or compounds). The insulating coating films 222 cover the entire surfaces of the first cores 221, respectively. The material of the insulating coating films 222 is the oxide of the first cores 221, for example. The material of the insulating coating films 222 may not be the oxide of the first cores 221 but may be silicon oxide, silicon nitride, or an insulating resin, for example. With the insulating coating films 222 covering the entire surfaces of the first cores 221, each first particle 22 is insulating. The particle size of the first cores 221 is, for example, about several hundred nanometers to several tens of micrometers, and the film thickness of the insulating coating films 222 is, for example, about several nanometers to several tens of nanometers. Each first particle 22 may be made insulating by the entire particle being made of an oxide-based magnetic material such as ferrite, rather than by the entire surface of the first core 221 being covered with the insulating coating film 222.
Each of the second particles 23 is in contact with the conductor 3 within the resin material 20. The plurality of second particles 23 each include a second core 231.
The second cores 231 are made of metallic magnetic powder. This metallic magnetic powder is the same as the metallic magnetic powder of the first cores 221. That is, as the metallic magnetic powder of the second cores 231, materials containing a metallic element that exhibits ferromagnetism by itself are preferably used, examples of which include materials containing one or more elements selected from Fe, Co, and Ni. The particle size of the second cores 231 is the same as that of the first cores 221.
As shown in
The conductor 3 serves as the functional center of the circuit component A1. In the circuit component A1, the conductor 3 forms the inductor portion. In the present embodiment, the conductor 3 is wound into a toroidal shape. As shown in
The first conductor layer 31 and the second conductor layer 32 face each other, with the resin composite body 2 interposed therebetween. In the example shown in
The first conductor layer 31 is separated into a plurality of first conductor portions 311. The second conductor layer 32 is separated into a plurality of second conductor portions 321. The first conductor portions 311 and the second conductor portions 321 are arranged such that a part of each first conductor portion overlaps with a part of a second conductor portion in plan view. In the example shown in
The conducting portion 33 connects the first conductor layer 31 and the second conductor layer 32 to each other. The conducting portion 33 penetrates the resin composite body 2 in the z direction. The conducting portion 33 includes a plurality of vias 331.
Each of the vias 331 penetrates the resin composite body 2 in the z direction and electrically connects one of the first conductor portions 311 and one of the second conductor portions 321. Each via 331 is formed in an area in which one of the first conductor portions 311 and one of the second conductor portions 321 overlap with each other in plan view. Each via 331 is connected to one of the first conductor portions 311 at one end in the z direction and connected to one of the second conductor portions 321 at the other end in the z direction.
The plurality of vias 331 include a plurality of inner vias 331a and a plurality of outer vias 331b. Each of the inner vias 331a connects one of the first conductor portions 311 and one of the second conductor portions 321, on the radially inner side of the conductor 3. The outer vias 331b connect each of the first conductor portions 311 and a relevant one of the second conductor portions 321, on the radially outer side of the conductor 3.
In plan view, each first conductor portion 311 overlaps with two conductor portions 321 adjacent to each other in the circumferential direction (toroidal direction) of the conductor 3, and an inner via 331a is disposed in an area in which the first conductor portion 311 overlaps with one of the second conductor portions 321, whereas an outer via(s) 331b is disposed in an area in which the first conductor portion 311 overlaps with the other one of the second conductor portions 321. Thus, the inner via 331a and the outer via 331b connecting to a given first conductor portion 311 are connected to two different second conductor portions 321 adjacent to each other in the toroidal direction of the conductor 3. With such a configuration, a current flows from a first conductor portion 311 to another first conductor portion 311 next to it in the toroidal direction through an inner via 331a, a second conductor portion 321 and an outer via 331b in that order. In the example shown in
The conductor 3 is designed such that a predetermined self-inductance is provided by the first conductor layer 31, the second conductor layer 32 and the conducting portion 33. Preferably, the self-inductance is 10 nH or greater, for example.
The connecting portions 34 connect the first conductor layer 31 and the second conductor layer 32 to the paired terminals 35, respectively. The connecting portions 34 include one connecting the first conductor layer 31 and one of the paired terminals 35, and another one connecting the second conductor layer 32 and the other one of the paired terminals 35.
The pair of terminals 35 are the input and output terminals for current in the circuit component A1. One of the terminals 35 connects to one of the first conductor portions 311 through a connecting portion 34. The other one of the terminals 35 connects to one of the second conductor portions 321 through a connecting portion 34. The current input to one of the terminals 35 is output from the other terminal 35. In the example shown in
Next, a method for manufacturing the circuit component A1 is described below with reference to
First, a support substrate 1 is prepared. For preparation of the support substrate 1, an insulating substrate, such as a silicon substrate, a glass epoxy substrate, or a ceramic substrate is used, for example. The support substrate 1 is rectangular in plan view, for example.
Next, a second conductor layer 32 is formed on the support substrate 1. To form the second conductor layer 32, a plating layer is formed on the entire upper surface of the support substrate 1, and the plating layer is patterned by photolithography, as shown in
Next, a resin composite body 2 is formed on the support substrate 1 to cover the second conductor layer 32. The resin composite body 2 is made of a resin material 20 containing a plurality of magnetic particles 21. In the resin composite body 2 formed on the support substrate 1, all of the magnetic particles 21 are the first particles 22 and include first cores 221 made of metallic magnetic powder and insulating coating films 222 that are the oxide of the metallic magnetic powder. That is, in this state, the surfaces of all magnetic particles 21 are covered with insulating coating films.
Next, as shown in
Next, a first conductor layer 31 is formed on the upper surface of the resin composite body 2. To form the first conductor layer 31, the upper surface of the resin composite body 2 is irradiated with a laser light at an area in which the first conductor layer 31 is to be formed. In the resin composite body 2 irradiated with a laser light, the resin material 20 melts. Some of the molten resin material 20 may disappear. The portion recessed from the upper surface of the resin composite body 2 in
The circuit component A1 shown in
Next, a semiconductor device B1 that uses the circuit component A1 is described below with reference to
As shown in
The circuit board 91 is a printed board, for example. The circuit board 91 supports the circuit component A1, the transistor Tr, the capacitor C and the sealing member 92. The circuit board 91 is formed with a conductor pattern (not shown), through which elements such as the circuit component A1, the transistor Tr, and the capacitor C are electrically connected as appropriate. In the state in which the circuit component A1 is mounted on the circuit board 91, the surface formed with the terminals 35 faces the circuit board 91, with the terminals 35 bonded to the conductor pattern. In the example in which the semiconductor device B1 has the BGA package structure, the circuit board 91 is formed with a plurality of small ball-shaped electrodes 911 on the surface (lower surface) opposite, in the z direction, to the surface (upper surface) on which the elements such as the circuit component A1, the transistor Tr, the capacitor C, and the sealing member 92 are disposed.
The sealing member 92 is formed on the circuit board 91 to cover the elements such as the circuit component A1, the transistor Tr, and the capacitor C. The material of the sealing member 92 is an insulating resin, which may be epoxy resin in one example.
The transistor Tr is a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), or a HEMT (High Electron Mobility Transistor), for example. The material of the transistor Tr is a semiconductor material such as Si, Sic, or GaN.
Advantages of the circuit component A1 and the semiconductor device B1 are described below.
The circuit component A1 includes the resin composite body 2 and the conductor 3. The resin composite body 2 contains a plurality of magnetic particles 21 in the resin material 20. The plurality of magnetic particles 21 are dispersed in the resin material 20. With such a configuration, part of the magnetic flux generated due to the current flowing in the conductor 3 concentrates on the plurality of magnetic particles 21, so that leakage of the magnetic flux reduces. Thus, the inductance value of the circuit component A1 is improved. Further, each of the magnetic particles 21 is smaller than bar-shaped or annular magnetic cores, so that the loop area of the eddy current can be made smaller. That is, the use of a plurality of magnetic particles 21 reduces eddy current loss and iron loss. In particular, since the eddy current loss is proportional to the square of the frequency of the current flowing the conductor 3, the higher the frequency of the current flowing in the conductor 3, the more effective the reduction of eddy current loss is. Thus, the circuit component A1 achieves both improvement of the inductance value and reduction of iron loss. Moreover, since the magnetic flux leakage is reduced, adverse effect of the magnetic flux leakage on other equipment can be reduced.
In the circuit component A1, the plurality of magnetic particles 21 include a plurality of first particles 22. The first particles 22 are insulating and dispersed in the resin material 20 in the resin composite body 2. When at least a portion of the conductor 3 (the first conductor layer 31 in the present embodiment) is to be formed by electroless plating, if all magnetic particles 21 are conductive (i.e., with no first particles 22 included), plating may grow on seeds or magnetic particles 21 appearing on the surface of the resin composite body 2. In such a case, selective formation of the conductor is not possible. In the circuit component A1, on the other hand, the first particles 22 dispersed in the resin material 20 in the resin composite body 2 are insulating. Thus, when the first particles 22 have appeared on the surface of the resin composite body 2, plating will not grow on such first particles 22. Thus, selective formation of the conductor 3 is possible in the circuit component A1.
In the circuit component A1, the plurality of magnetic particles 21 include a plurality of second particles 23. The second particles 23 are in contact with the conductor 3 (e.g., the first conductor layer 31). Each second particle 23 includes a second core 231, and the second core 231 forms at least a portion of the surface of the second particle 23. The second cores 231 are made of metallic magnetic powder having the same composition as the metallic magnetic powder of the first cores 221. Each second particle 23 is a magnetic particle 21 that has subjected to laser light irradiation and formed by partially or entirely destroying the insulating coating film 232 covering the surface of the second core 231 by laser light irradiation. Examples of a method for forming a conductor on the surface of a resin material include LDS (Laser Direct Structuring). In LDS, metal cores are formed on the surface of a resin material containing an LDS additive by using a laser, and a conductor is selectively formed only at the laser irradiated areas by e.g., electroless plating using the metal cores as seeds. In this way, an LDS additive is needed in LDS. In the circuit component A1, on the other hand, metal cores are formed from some of magnetic particles (second particles 23), instead of an LDS additive. That is, in the circuit component A1, a portion of the conductor 3 (the first conductor layer 31 in the present embodiment) can be formed by a process similar to LDS without adding an LDS additive. Moreover, since a portion of the conductor 3 can be formed by a process similar to LDS, a fine conductor pattern (each first conductor portion 311) can be formed. Thus, the circuit component A1 can be miniaturized.
In the circuit component A1, the insulating coating film 222 of each of the first particles 22 is formed of the oxide of the first core 221. According to such a configuration, the insulating coating film 222 can be formed on the surface of the first core 221 by thermally oxidizing the first core 221. That is, the insulating coating film 222 is formed by thermally oxidizing metallic magnetic powder forming the first core 221. Thus, in the circuit component A1, the insulating magnetic particles 21, i.e., the first particles 22 are easily formed.
In the circuit component A1, the conductor 3 is wound into a toroidal shape. With such a configuration, the magnetic flux generated by the current flowing in each of the first conductor portion 311 of the first conductor layer 31 and the magnetic flux generated by the current flowing in each of the second conductor portion 321 of the second conductor layer 32 point in the same direction in the area sandwiched between the first conductor layer 31 and the second conductor layer 32 in the z direction and point in opposite directions in the areas outside the first conductor layer 31 and the second conductor layer 32 (i.e., above the first conductor layer 31 and below the second conductor layer 32) in the z direction. Thus, the circuit component A1 can reduce magnetic flux leakage while improving the inductance value.
The semiconductor device B1 includes the circuit component A1 and the transistor Tr. As described above, the circuit component A1 reduces magnetic flux leakage. Thus, the semiconductor device B1 can reduce the adverse effect of magnetic flux leakage from circuit component A1 on the operation of transistor Tr.
In the semiconductor device B1, the transistor Tr and the circuit component A1 are covered with the sealing member 92. With such a configuration, the transistor Tr and the circuit component A1 are packaged together as one unit. Thus, the semiconductor device B1 can be miniaturized by miniaturizing the circuit component A1.
In the first embodiment, the shapes of the first conductor portions 311 (the first conductor layer 31) and the second conductor portions 321 (the second conductor layer 32) are not limited to the above-described examples. For example, the configuration shown in
In the first embodiment, a resin member may be formed on top of the resin composite body 2 (i.e., on the side opposite, in the z direction, from the side on which support substrate 1 is disposed).
In the first embodiment, the support substrate 1 may be made of the same material as the resin composite body 2. That is, the support substrate 1 may not be an insulating substrate but may be made of a resin material 20 in which a plurality of magnetic particles 21 are dispersed.
In the first embodiment, the circuit component A1 may not include the support substrate 1.
In the first embodiment, to improve the formation accuracy in forming a portion (e.g., the first conductor layer 31) of the conductor 3 by laser light irradiation and electroless plating, the above-described LDS additive may be added to the resin material 20 of the resin composite body 2, in addition to the magnetic particles 21.
A circuit component A2 according to a second embodiment is described below with reference to
As shown in
In the circuit component A2, the current inputted to one of the terminals 35 is inputted to the first conductor layer 31 through the connecting portion 34 connecting to that terminal 35. The current inputted to the first conductor layer 31 flows through the first conductor layer 31 to be inputted to the second conductor layer 32 through the conducting portion 33. The current inputted to the second conductor layer 32 flows through the second conductor layer 32 and outputted from the other terminal 35 through the connecting portion 34 connecting to the second conductor layer 32.
As with the circuit component A1, the circuit component A2 also includes a resin composite body 2 and a conductor 3. Thus, as with the circuit component A1, the circuit component A2 can improve the inductance value, because part of the magnetic flux generated due to the current flowing in the conductor 3 concentrates on the plurality of magnetic particles 21. Further, the use of a plurality of magnetic particles 21 reduces eddy current loss and iron loss. Thus, as with the circuit component A1, the circuit component A2 achieves both improvement of the inductance value and reduction of iron loss.
The circuit component A2 have the same advantages as the circuit component A1 due to its common configuration with the circuit component A1. The circuit component A2 may be used in place of the circuit component A1 in the semiconductor device B1.
The circuit component A2 can be configured in the same manner as each of the above-described variations of the circuit component A1. For example, in the circuit component A2 again, a resin member 5 may be formed on the upper surface of the resin composite body 2, the support substrate 1 may be made of the same material as the resin composite body 2, or the support substrate 1 may be dispensed with.
The first embodiment and the second embodiment show examples in which the conductor 3 forms an inductor. However, the present disclosure is not limited to this, and the conductor 3 may form a transformer or an LC filter. For a transformer, the conductor 3 forms two windings. The two windings are arranged to be magnetically coupled to each other. For an LC filter, the conductor 3 forms an inductor portion and a capacitor portion.
The circuit component and the semiconductor device according to the present disclosure are not limited to the foregoing embodiments. The specific configuration of each part of the circuit component and the semiconductor device according to the present disclosure may be varied in design in many ways. For example, the circuit component and the semiconductor device according to the present disclosure include embodiments described in the following clauses.
Clause 1.
A circuit component comprising:
Clause 2.
The circuit component according to clause 1, wherein the plurality of magnetic particles include a first particle that is insulating.
Clause 3.
The circuit component according to clause 2, wherein the first particle includes a first core made of metallic magnetic powder and an insulating coating film covering an entire surface of the first core.
Clause 4.
The circuit component according to clause 3, wherein the insulating coating film is made of an oxide of the first core.
Clause 5.
The circuit component according to clause 3 or 4, wherein the plurality of magnetic particles further include a second particle that is in contact with the conductor,
Clause 6.
The circuit component according to any one of clauses 1 to 5, wherein a material of the conductor includes Cu.
Clause 7.
The circuit component according to any one of clauses 1 to 6, wherein the plurality of magnetic particles contain one of Fe, Ni and Co.
Clause 8.
The circuit component according to any one of clauses 1 to 7, wherein the resin composite body has a relative magnetic permeability of 10 or greater.
Clause 9.
The circuit component according to any one of clauses 1 to 8, wherein the conductor forms an inductor.
Clause 10.
The circuit component according to clause 9, wherein the inductor has a self-inductance of 10 nH or greater.
Clause 11.
The circuit component according to any one of clauses 1 to 10, wherein the conductor includes a first conductor layer, a second conductor layer, and a conducting portion,
Clause 12.
The circuit component according to clause 11, wherein the first conductor layer is divided into a plurality of first conductor areas,
Clause 13.
A semiconductor device comprising:
Clause 14.
The semiconductor device according to clause 13, further comprising a sealing member made of a resin,
Clause 15.
The semiconductor device according to clause 13 or 14, wherein the transistor is one of a MOSFET, an IGBT, or a HEMT.
Clause 16.
The semiconductor device according to any one of clauses 13 to 15, wherein a material of the transistor includes one of SiC, Si, or GaN.
Number | Date | Country | Kind |
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2020-168339 | Oct 2020 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2021/032596 | 9/6/2021 | WO |