JP7101645B2 - Coil parts - Google Patents

Description

The present invention relates to coil components.

Conventionally, as a coil component, there is one described in US6,362,986B1 (Patent Document 1). This coil component has a plurality of (N) coils, and these coils are negatively magnetically coupled (hereinafter, may be simply referred to as "negative coupling") through a common core and are excited. The inductance is greater than about 3 times the leakage inductance. This indicates that the leakage inductance is small, that is, the coils are strongly negatively coupled to each other. Further, in the coil component, even when N is larger than 3, all the coils are strongly negatively coupled by winding the coil around a common core. In particular, the coil component discloses a configuration in which at least two or more coils that are most strongly negatively coupled to each coil are present. The coil component is used in an output voltage smoothing circuit of a multi-phase switching regulator (hereinafter referred to as "multi-phase SW regulator"). In the multi-phase SW regulator, in order to reduce the ripple voltage input to the smoothing capacitor, if the period of the pulse signal input to each coil (interval between turn-on transitions) is expressed in phase as 360 °, these pulse signals will be expressed in phase. It is input to each coil with a phase difference of 360 ° / N. In the steady state where there is no load fluctuation, the duty ratio of the pulse signal is constant, and the duty ratio is the same value between the pulse signals.

US6,362,986B1

In the conventional coil component, for example, when N = 2, a pulse signal having a phase difference of 180 ° is input to the two coils. Here, assuming that the duty ratio of the pulse signal is 50%, the period in which the input pulse signal is on in one coil (on period) is the period in which the input pulse signal is in the off state in the other coil. It will be a certain period (off period). At this time, the current increases in one coil and decreases in the other coil, but since these coils are negatively coupled through the core, the change in magnetic flux in the core due to the current change is in the same direction and becomes mutual. Strengthen each other. Therefore, the rate of change of the magnetic flux in the core is larger than the rate of change of the magnetic flux in the core when the two coils are not magnetically coupled (hereinafter, may be simply referred to as "uncoupled"). The effective inductance of each coil is larger than in the case of no coupling. As a result, the rate of increase in current in one coil decreases, the rate of decrease in current in the other coil decreases, and the ripple current in each coil becomes smaller than in the case of no coupling. In particular, when the coupling coefficient of the two coils is -1, the ripple current becomes 0 and a direct current flows through each coil. In the present application, the "ripple current" refers to the difference (Ipp) between the maximum value and the minimum value of the current (coil current) flowing through each coil. Further, when the capacity of the smoothing capacitor has a margin for the reduced ripple, the transient response speed can be improved by reducing the inductance of each coil.

However, the inventor of the present application has found that the conventional coil component has the following problems. For example, depending on the number of coils (N) and the duty ratio of the pulse signal, there may be a period (simultaneous on period) in which two or more coils in which the input pulse signal is in the ON state exist at the same time. During the simultaneous on period, the current increases in the two or more coils, but in the conventional coil component, the two or more coils are negatively coupled, and the magnetic flux in the core due to the current change of the two coils The changes are in opposite directions and cancel each other out. Further, in the conventional coil component, since the negative coupling of the two or more coils is strong and the amount of magnetic fluxes canceling each other is large, the rate of change of the magnetic flux in the core during the simultaneous on period is higher than that in the case of no coupling. It may be smaller. At this time, since the effective inductance of each coil is smaller than that in the case of no coupling, the rate of change of the current in each coil is increased, and the ripple current may be increased. This also applies to the simultaneous off period, that is, the period in which two or more coils in which the input pulse signal is in the off state exist at the same time. Therefore, if all the coils are strongly negatively coupled (at least two or more coils are most strongly negatively coupled to each coil) as in the conventional coil component, the ripple current may increase.

Therefore, an object of the present invention is to provide a coil component capable of reducing the ripple current of the coil when used in a polyphase SW regulator, and a switching regulator including the coil component.

The coil component according to one aspect of the present invention is
It has 2N coils (N is an integer of 2 or more) and has
The 2N coils are configured to form N pairs.
When a coil other than the first coil and the second coil forming one of the N pairs is used as the other coil, the magnetic coupling between the first coil and the second coil is the first coil and the other coil. Stronger than the magnetic coupling with the coil.

Here, the coils connected in series in the coil component are regarded as one coil. "The magnetic coupling between the first coil and the second coil is stronger than the magnetic coupling between the first coil and the other coils" means that "the absolute value of the coupling coefficient between the first coil and the second coil is the first. It is larger than the absolute value of the coupling coefficient between one coil and the other coils. "

According to the coil component of the above aspect, the magnetic coupling between the paired first coil and the second coil is stronger than the magnetic coupling between the first coil and the other coils. Thereby, when the coil component of the above aspect is used for the polyphase SW regulator, the ripple current of the first coil can be reduced by appropriately selecting the pulse signal input to each coil.

Further, in one embodiment of the coil component, the magnetic coupling between the first coil and the second coil is stronger than the magnetic coupling between the second coil and the other coils.

According to the above embodiment, when used in a polyphase SW regulator, the ripple current of the second coil can be reduced by appropriately selecting the pulse signal input to each coil.

Further, in one embodiment of the coil component, the magnetic coupling between the paired coils is stronger than any of the magnetic couplings between the unpaired coils.

According to the above embodiment, when used in a polyphase SW regulator, the ripple current of each coil can be reduced by appropriately selecting the pulse signal input to each coil.

Further, in one embodiment of the coil component, a current is passed through the first coil and the second coil in a direction of negative coupling so that the magnetic fluxes cancel each other out.

According to the above embodiment, since a current flows through the first coil and the second coil in the direction of negative coupling, when a signal having a phase difference of 180 ° is input to the first coil and the second coil, the first coil is used. , The ripple current of the second coil can be reduced. In addition, "the magnetic fluxes cancel each other out" means that the magnetic fluxes cancel each other out in a place where the density of the magnetic flux is mainly high, such as the inner diameter portion of the coil, and the density of the magnetic flux is relatively high such as the peripheral part of the coil. At low points, the magnetic fluxes may be strengthened.

Further, in one embodiment of the coil component,
Further provided with a prime field in which a plurality of insulating layers are laminated in the first direction,
Each of the 2N coils is arranged inside the prime field and is composed of spiral wiring wound on the insulating layer.
For each of the 2N coils, it is assumed that the inner side of the innermost circumference of the spiral wiring is the inner diameter portion of the coil.
When viewed from the first direction, at least a part of the inner diameter portion of the first coil and at least a part of the inner diameter portion of the second coil overlap each other.

According to the above embodiment, at least a part of the inner diameter portion of the first coil and at least a part of the inner diameter portion of the second coil overlap each other. As a result, when the magnetic flux of the first coil is generated in the inner diameter portion of the first coil along the axis of the first coil, the magnetic flux passes through the inner diameter portion of the second coil. Further, when the magnetic flux of the second coil is generated in the inner diameter portion of the second coil along the axis of the second coil, the magnetic flux passes through the inner diameter portion of the first coil. Therefore, the magnetic coupling between the paired first coil and the second coil can be strengthened. In the present application, the spiral wiring refers to a curved wiring wound on a plane such as an insulating layer, and as shown in an embodiment to be described later, the spiral wiring has a number of turns (number of turns). ) Is less than one round, and curved wiring is also included.

Further, in one embodiment of the coil component, the inner diameter portion of the first coil and the inner diameter portion of the other coil do not overlap each other.

According to the above embodiment, the magnetic coupling between the unpaired first coil and the other coil can be weakened.

Further, in one embodiment of the coil component, the first coil and the second coil are wound in different directions.

According to the above embodiment, the first coil and the second coil can be easily negatively coupled. In the present application, the fact that the two coils are wound in different directions means that, for example, when both ends of each of the two coils are pulled out to one and the other when viewed from the first direction, one side is used. It means that the winding direction from to the other side is different. Specifically, for example, when one coil is wound clockwise from one side to the other when viewed from the first direction, the other coil is counterclockwise from one side to the other. It means that it is wound clockwise.

Further, in one embodiment of the coil component,
A plurality of the coils are laminated on the same insulating layer, and the coils are laminated.
The plurality of the coils are wound in the same direction.

According to the above embodiment, since the plurality of coils laminated on the same insulating layer are wound in the same direction, the same insulating layer having a relatively large magnetic coupling among the pair of unpaired coils. A set of adjacent coils can be easily negatively coupled above, and the ripple current of each coil can be further suppressed.

Further, in one embodiment of the coil component, the 2N coils are all wound in the same direction.

According to the above embodiment, since the 2N coils are all wound in the same direction, the deviation of the electrical characteristics can be reduced and the manufacturing can be facilitated. In addition, the paired coils can be easily positively coupled.

Further, in one embodiment of the coil component, the insulating layer on both sides of the spiral wiring of the 2N coils includes a magnetic resin layer made of a composite material of magnetic powder and resin.

According to the above embodiment, since the insulating layers on both sides in the first direction with respect to the spiral wiring include a magnetic resin layer, a coil component capable of ensuring an appropriate inductance and coupling coefficient while being small and thin can be inexpensively used. Can be provided.

Further, in one embodiment of the coil component,
The average particle size of the magnetic powder is 0.5 μm or more and 100 μm or less.
The magnetic powder is contained in an amount of 50 vol% or more and 85 vol% or less with respect to the resin.

According to the above embodiment, since the average particle size of the magnetic powder is 0.5 μm or more and 100 μm or less, the magnetic resin can be used as a small core. Further, since the magnetic powder is contained in an amount of 50 vol% or more and 85 vol% or less with respect to the resin, a sufficient magnetic permeability can be obtained and the magnetic bond between the paired coils can be strengthened.

Further, in one embodiment of the coil component,
For each of the 2N coils, a magnetic resin body made of a magnetic material powder and a resin composite material provided outside the inner diameter portion of the coil and the outermost circumference of the spiral wiring of the coil is further provided. Prepare,
The magnetic resin layer and the magnetic resin body form a closed magnetic path.

According to the above embodiment, the magnetic resin layer and the magnetic resin body form a closed magnetic path. As a result, the leakage flux can be reduced, noise can be suppressed, and the magnetic coupling between the paired coils can be strengthened while the magnetic coupling between the unpaired coils can be weakened.

Further, in one embodiment of the coil component,
The first coil and the second coil are each composed of a plurality of the spiral wirings wound on the plurality of the insulating layers.
The most extreme distance between the first coil and the second coil is longer than the shortest distance between the spiral wirings in each of the first coil and the second coil.

According to the above embodiment, the shortest distance between the first coil and the second coil is longer than the shortest distance between the respective spiral wirings, so that the period during which the different voltage is applied is relatively long. The insulation between the 1st coil and the 2nd coil can be relatively improved, and the reliability can be improved.

Further, in one embodiment of the coil component,
The spiral wiring of a plurality of the coils is wound around the same insulating layer.
The shortest distance between the spiral wirings is longer than the wiring spacing in the spiral wirings.

According to the above embodiment, the shortest distance between adjacent spiral wires wound on the same insulating layer is longer than the wiring interval in the spiral wiring, so that different voltages are applied to the adjacent spiral wires. The insulation between the spiral wirings wound on the same insulating layer of the coil can be relatively improved, and the reliability can be improved.

Further, in one embodiment of the coil component, the insulating layer in contact with the spiral wiring is made of a composite material of insulator powder and resin.

According to the above embodiment, the insulation in the spiral wiring and between the spiral wiring can be further improved.

Further, in one embodiment of the coil component,
One end of the first coil and one end of the second coil are drawn out to the same one side with respect to the first coil and the second coil, and the other end of the first coil and the second coil. The other end of the coil is drawn out to the same other side of the first coil and the second coil.
The first coil and the second coil are wound so that magnetic fluxes cancel each other when a current flows from one end to the other end.

According to the above embodiment, when the pulse signal is input so that the paired first coil and the second coil are negatively coupled, the input end and the output end of the first and second coils are aligned on the same side. can. Therefore, it is possible to facilitate wiring routing on the board on which the coil components are mounted.

Further, in one embodiment of the coil component, the number of turns, the coil wiring length, and the coil cross-sectional area of each of the first coil and the second coil are the same.

According to the above embodiment, since the number of turns, the coil wiring length, and the coil cross-sectional area of each of the first coil and the second coil are the same, the deviation of the electrical characteristics of each coil can be reduced.

Further, in one embodiment of the coil component, the first external terminal connected to the one end of the first coil and the second external terminal connected to the one end of the second coil are adjacent to each other.

According to the above embodiment, since the first external terminal and the second external terminal are adjacent to each other, the coil component can be miniaturized.

Further, in one embodiment of the switching regulator,
With the coil parts
2N switch parts connected to each end side of each coil of the coil component,
A smoothing circuit connected to one end or the other end of each coil of the coil component is provided.
The switch unit inputs a signal having a phase difference of 180 ° to the pair of coils of the coil component.

According to the embodiment, since the coil component is provided, the performance can be improved and the size can be reduced by reducing the ripple current of the coil.

According to the coil component of the present invention, the magnetic coupling between the paired first coil and the second coil is stronger than the magnetic coupling between the first coil and the other coils, so that when used in a polyphase SW regulator, By appropriately selecting the pulse signal input to each coil, the ripple current of the first coil can be reduced.

It is a simplified block diagram which shows the coil component 1 which concerns on 1st Embodiment. It is a perspective view which shows the coil component 1A which concerns on 2nd Embodiment. It is an exploded perspective view of the coil component 1A. FIG. 2 is a cross-sectional view taken along the line XX of FIG. It is explanatory drawing explaining the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is explanatory drawing explaining the 2nd Embodiment of the manufacturing method of the coil component 1A. It is a perspective view which shows the coil component of the comparative example 2. FIG. It is a graph which shows the relationship between the input voltage and the current of each coil in this Example. It is a graph which shows the relationship between the input voltage and the current of each coil in the comparative example 1. FIG. It is a graph which shows the relationship between the input voltage and the current of each coil in the comparative example 2. FIG. It is an exploded perspective view which shows the coil component 1B which concerns on 3rd Embodiment. It is sectional drawing which shows the coil component 1B which concerns on 3rd Embodiment. It is an exploded perspective view which shows the coil component 1C which concerns on 4th Embodiment. It is sectional drawing which shows the coil component 1C which concerns on 4th Embodiment. It is a perspective view which shows the coil component 1D which concerns on 5th Embodiment. 12A is a cross-sectional view taken along the line XX of FIG. 12A. It is a perspective top view which shows the coil component 1D. It is a perspective view which shows the coil component 1E which concerns on 6th Embodiment. 13A is a cross-sectional view taken along the line XX of FIG. 13A. It is a perspective top view which shows the coil component 1E. It is a perspective view which shows the coil component 1F which concerns on 7th Embodiment. 14A is a cross-sectional view taken along the line XX of FIG. 14A. It is a perspective top view which shows the coil component 1F. It is a perspective perspective view which shows the coil component 1G which concerns on the modification of 7th Embodiment. It is a perspective view which shows the coil component 1H which concerns on the modification of 7th Embodiment. It is a schematic diagram which shows the coil component 1J which concerns on 8th Embodiment. It is a simplified block diagram which shows the switching regulator 5 which concerns on one Embodiment.

Hereinafter, one aspect of the present invention will be described in detail with reference to the illustrated embodiments.

(First Embodiment)
FIG. 1 is a simplified configuration diagram showing a coil component 1 according to the first embodiment. As shown in FIG. 1, the coil component 1 has 2N coils (N is an integer of 2 or more) L1, L2, ... L (2N). The 2N coils L1 to L (2N) are configured to form an N pair. Specifically, the first coil L1 and the second coil L2 form a pair, the third coil L3 and the fourth coil L4 form a pair, and similarly, the second (2N-1) coil L (2N-). 1) and the second (2N) coil L (2N) form a pair. That is, when generalized, M is an integer of 1 or more and N or less, and the (2M-1) coil L (2M-1) and the (2M) coil L (2M) form a pair.

Here, the 2N coils L1, L2, ... L (2N) of the coil component 1 are magnetically coupled to each other. However, the magnetic coupling between the paired first coil L1 and the second coil L2 is stronger than the magnetic coupling between the unpaired first coil L1 and the other coils L3 to L (2N). That is, the absolute value of the coupling coefficient between the first coil L1 and the second coil L2 is larger than the absolute value of the coupling coefficient between the first coil L1 and the other coils L3 to L (2N).

Specifically, the magnetic coupling K12 of the first and second coils is stronger than the magnetic coupling K13 of the first and third coils and the magnetic coupling K1 (2N) of the first and first (2N) coils. In the figure, the solid arrow indicates a strong magnetic bond, and the dotted arrow indicates a weak magnetic bond. Further, the first coil L1 and the second coil L2 are negatively coupled to each other so that the magnetic fluxes cancel each other out, specifically, from the input side (for example, the left side of FIG. 1) to the output side (for example, the right side of FIG. 1). A current is passed through.

Not only when the first coil L1 is used as a reference, but also when the coils L2 to L (2N) are used as a reference, the magnetic coupling between the reference coil and the paired coil is similarly performed. It is stronger than the magnetic coupling between the reference coil and other unpaired coils. For example, based on the second coil L2, the magnetic coupling between the first coil L1 and the second coil L2 is stronger than the magnetic coupling between the second coil L2 and the other coils L3 to L (2N). Further, in each of the paired coils, a current is passed in the direction of negative coupling so that the magnetic fluxes of each other cancel each other out. Further, in the coil component 1, the magnetic coupling between the paired coils is stronger than any of the magnetic couplings between the unpaired coils. Specifically, for example, the magnetic coupling between the first coil L1 and the second coil L2 that form a pair is the magnetic coupling between the third coil L3 and the (2N-1) coil L (2N-1) that do not form a pair. Stronger than.

According to the coil component 1, the magnetic coupling between the paired first coil L1 and the second coil L2 is larger than the magnetic coupling between the unpaired first coil L1 and the other coils L3 to L (2N). strong. As a result, when the coil component 1 is used in the polyphase SW regulator, the ripple current of the first coil L1 can be reduced by appropriately selecting the pulse signal input to each coil L1 to L (2N). can.

Specifically, first, the coil component 1 has 2N coils L1 to L (2N), and when used in a polyphase SW regulator, the total number of pulse signals input to the coil component 1 is 2N. Therefore, these are used as signals P1 to P (2N). At this time, the cycles of the signals P1 to P (2N) are the same, and when the period is represented by a phase as 360 °, the signals P1 to P (2N) are a set of signals having a phase difference of 360 ° / 2N. Become. Further, in the steady state where there is no load fluctuation, each signal P1 to P (2N) has a constant and same duty ratio. Here, since 2N is an even number, there are two pulse signals having a phase difference of 180 ° in the 2N signals P1 to P (2N).

Therefore, the signal P1 input to the first coil L1 is one of the above two pulse signals, and the signal P2 input to the second coil L2 paired with the first coil L1 is the above two pulse signals. Consider the case of the other. The signal P2 has a phase difference of 180 ° from the signal P1, and is a signal having the largest phase difference with respect to the signal P1 among the signals P2 to P (2N). That is, considering the interval between the turn-on transitions (or turn-off transitions) of the signals P2 to P (2N) with respect to the turn-on transition (or turn-off transition) of the signal P1, the signal P2 is the signal having the largest interval. This is a period during which the signal P2 can reduce the ripple current due to the negative coupling of the coil with respect to the signal P1 among the signals P2 to P (2N) (one is on and the other is off). ) Is the longest, which means that the signal has the shortest period (simultaneous on period and simultaneous off period) in which an increase in ripple current due to negative coil coupling is a concern. That is, the signal P2 is a signal in which the ripple current reduction effect due to the negative coupling of the coil is most exhibited with respect to the signal P1. In the coil component 1, by inputting such a signal P2 to the second coil L2 which is relatively strongly negatively coupled to the first coil L1 to which the signal P1 is input, the ripple current of the first coil L1 is effective. Can be made smaller.

Further, in the above case, the signals P3 to P (2N) input to the other coils L3 to L (2N) that are not paired with the first coil L1 have a phase difference from the signal P1 between the signal P1 and the signal P2. The signal is smaller than the phase difference between. That is, in the signals P3 to P (2N), the interval between the turn-on transitions or the interval between the turn-off transitions is relatively small with respect to the signal P1. This is because the signals P3 to P (2N) have a relatively short period in which the ripple current can be reduced due to the negative coupling of the coil with respect to the signal P1, and there is a concern that the ripple current will increase due to the negative coupling of the coil. Means that is a relatively long signal. That is, the signals P3 to P (2N) are signals in which the effect of reducing the ripple current due to the negative coupling of the coil is relatively difficult to exert with respect to the first pulse signal, and there is a concern that the ripple current may increase. In the coil component 1, such signals P3 to P (2N) are input to the other coils L3 to L (2N) magnetically coupled to the first coil L1 to which the signal P1 is input. Therefore, it is possible to suppress an increase in the ripple current of the first coil L1.

As described above, when the coil component 1 is used in the polyphase SW regulator, the ripple current of the first coil L1 can be reduced by appropriately selecting the pulse signal input to each coil.

In particular, since a current flows through the first coil L1 and the second coil L2 in a direction in which the magnetic fluxes of each other are negatively coupled so as to cancel each other, a signal having a phase difference of 180 ° is sent to the first coil L1 and the second coil L2. When P1 and P2 are input, the inductor ripple current of the first and second coils L1 and L2 can be reduced.

Further, the relative strength relationship of the above coupling is the same not only when the first coil L1 is used as a reference but also when the coils L2 to L (2N) are used as a reference. Therefore, similarly to the first coil L1, when each coil L2 to L (2N) is used as a reference, a pulse signal having a phase difference of 180 ° is input to the reference coil and the paired coil. Therefore, the ripple current of each coil L2 to L (2N) can be reduced. In order to appropriately select the pulse signal in this way, for example, an arbitrary signal is first selected as the signal P1, and the signal P (2M-1) is (360 ° / (2N)) with respect to the signal P1. ) × (M-1), and the signal P (2M) is a signal having a phase difference of (360 ° / (2N)) × (M-1) + 180 ° with respect to the signal P1. It may be selected (M is an integer of 1 or more and N or less). Specifically, for example, when N = 2, an arbitrary signal is first selected as the signal P1 as the signals P1 to P4, and a signal having a phase difference of 180 ° with respect to the signal P1 is used as the signal P2. As P3, a signal having a phase difference of 90 ° with respect to signal P1 may be selected, and as signal P4, a signal having a phase difference of 270 ° with respect to signal P1 may be selected.

Therefore, in the coil component 1, when used for the multi-phase SW regulator, all the coils L1 are appropriately selected by appropriately selecting the signals P1 to P (2N) input to each coil L1 to L (2N) as described above. The ripple current of ~ L (2N) can be reduced. However, as inferred from the above, in the coil component 1, the magnetic coupling between the coil and the coil paired with the coil is paired with the coil with respect to at least one coil of the coils L1 to L (2N). It should be stronger than the magnetic coupling with other coils that do not form. At this time, the ripple current of the coil can be reduced by inputting a signal having a phase difference of 180 ° from the signal input to the coil to the coil paired with the coil. At this time, the strength of the magnetic coupling may be any with respect to a coil other than the coil. As described above, when any magnetic coupling between the paired coils is stronger than any magnetic coupling between the unpaired coils, the ripple current of each coil L1 to L (2N) is surely reduced. Can be and is preferred. Further, as described above, in the coil component 1, the coil "paired" with the coil with respect to a certain coil is a coil other than the coil that is most strongly magnetically coupled to the coil. Point to.

(Second Embodiment)
FIG. 2 is a perspective view showing the coil component 1A according to the second embodiment. FIG. 3 is an exploded perspective view of the coil component 1A. FIG. 4 is a cross-sectional view taken along the line XX of FIG. As shown in FIGS. 2, 3 and 4, the coil component 1A includes a prime field 10 and 4 (2 × 2) first to fourth coils L1 to L4 provided in the prime field 10. It has first to fourth external terminals provided outside the prime field 10 and electrically connected to the first to fourth coils L1 to L4. Further, the first to fourth external terminals include external terminals 11a to 14a provided on the first side surface 10a side of the prime field 10 and external terminals 11b to 14b provided on the second side surface 10b side of the prime field 10. Consists of. The first side surface 10a and the second side surface 10b face each other, and the external terminals 11a to 14a and the external terminals 11b to 14b are arranged so as to face each other in this order. The first to fourth external terminals 11a to 14a and 11b to 14b are, for example, a metal film such as Cu, Ni, Sn plated and formed on the surface of the element body 10, or a screen-printed low metal film such as Cu, Ag, Au. A resin film containing an electrically resistant metal.

The coil component 1A has a mounting surface on which both the external terminals 11a to 14a and the external terminals 11b to 14b shown in FIG. 2 are arranged. Further, in the following, the direction orthogonal to the mounting surface is the vertical direction (corresponding to the vertical direction of the paper surface in FIG. 4), the mounting surface side of the coil component 1A is downward, and the opposite surface side thereof is upward.

The prime field 10 has an insulating resin 35 that covers each of the first to fourth coils L1 to L4, and a magnetic resin 40 that covers the insulating resin 35. The insulating resin 35 is composed of a base insulating resin layer (insulating layer) 30 and first to fourth insulating resin layers (insulating layers) 31 to 34. The magnetic resin 40 includes a first magnetic resin body 41a provided in the first hole portion 35a of the insulating resin 35, a second magnetic resin body 41b provided in the second hole portion 35b of the insulating resin 35, and an insulating resin 35. It is composed of a third magnetic resin body 41c provided on a part of the outer peripheral surface of the above, and a magnetic resin layer (insulating layer) 42 provided on the upper and lower end surfaces of the insulating resin 35. As a result, the prime field 10 has a structure in which a plurality of insulating layers 30 to 34, 42 are laminated in the vertical direction. That is, the vertical direction of this embodiment corresponds to the first direction. In this specification, covering an object means covering at least a part of the object, and not only when the object is placed above the object, but also to the side or the lower side of the object. It is also called "covering" when it is placed in. In FIG. 3, the insulating resin 35 is omitted.

The first to fourth coils L1 to L4 are arranged inside the prime field 10, respectively, and are composed of a first spiral wiring 21 and a second spiral wiring 22 wound on the insulating layers 30 to 33. Here, for each of the first to fourth coils L1 to L4, the inner diameter portion is set inside the innermost circumference of the first and second spiral wirings 21 and 22. The inner diameter portion includes a winding center axis of each coil L1 to L4 along the vertical direction (hereinafter, may be simply referred to as "coil axis"). The second coil L2 is laminated above the first coil L1. The fourth coil L4 is laminated on the side of the first coil L1, that is, on the same insulating layer (base insulating resin layer 30). The third coil L3 is laminated above the fourth coil L4. The third coil L3 is laminated on the side of the second coil L2, that is, on the same insulating layer (second insulating resin layer 32).

Here, in the coil component 1A, it is assumed that the coils arranged in the vertical direction form a pair. At this time, the four coils L1 to L4 are configured to form two pairs of a pair of the first coil L1 and the second coil L2 and a pair of the third coil L3 and the fourth coil L4. There is. Next, the relationship between the magnetic coupling between the paired coils and the magnetic coupling between the unpaired coils will be described below.

In the coil component 1A, the inner diameter portion of the first coil L1 and the inner diameter portion of the second coil L2 overlap each other when viewed from the vertical direction. As a result, when the magnetic flux of the first coil L1 is generated in the inner diameter portion of the first coil L1 along the axis of the first coil L1, the magnetic flux passes through the inner diameter portion of the second coil L2. Further, when the magnetic flux of the second coil L2 is generated in the inner diameter portion of the second coil L2 along the axis of the second coil L2, the magnetic flux passes through the inner diameter portion of the first coil L1. Therefore, the paired first coil L1 and the second coil L2 are strongly magnetically coupled. In order to obtain a strong magnetic coupling, at least a part of the inner diameter portion of the first coil L1 and at least a part of the inner diameter portion of the second coil L2 may overlap each other, but the shaft of the first coil L1 When the axis of the second coil L2 is coaxial (the axes match), a stronger magnetic coupling can be obtained.

Similarly, in the coil component 1A, the inner diameter portion of the third coil L3 and the inner diameter portion of the fourth coil L4 overlap each other when viewed from the vertical direction. As a result, the paired third coil L3 and the fourth coil L4 are strongly magnetically coupled.

On the other hand, the axes of the first coil L1 and the second coil L2 and the axes of the third coil L3 and the fourth coil L4 are arranged in parallel with a gap. That is, when viewed from the vertical direction, the inner diameter portion of the first coil L1 and the inner diameter portion of the fourth coil L4 do not overlap each other, and the inner diameter portion of the second coil L2 and the inner diameter portion of the third coil L3 are It does not overlap with each other. As a result, the first coil L1 and the fourth coil L4 are compared with the magnetic coupling between the first coil L1 and the second coil L2 sharing the inner diameter portion and the magnetic coupling between the third coil L3 and the fourth coil L4. And the magnetic coupling between the second coil L2 and the third coil L3 is relatively weak. Further, the first coil L1 and the third coil L3, and the second coil L2 and the fourth coil L4 are also magnetically coupled, but the inner diameter portions do not overlap each other, and the distance between the coils is the largest. big. Therefore, the magnetic coupling between the first coil L1 and the third coil L3 and the second coil are compared with the magnetic coupling between the first coil L1 and the fourth coil L4 and the magnetic coupling between the second coil L2 and the third coil L3. The magnetic coupling between the coil L2 and the fourth coil L4 is relatively weak, and may be negligible in coil characteristics, for example.

From the above, in the coil component 1A, when the coils L3 and L4 other than the first coil L1 and the second coil L2, which are one of the two pairs, are the other coils L3 and L4, the first coil L1 and the second coil L1 and the second coil L4. The magnetic coupling with the coil L2 is stronger than the magnetic coupling between the first coil L1 and the other coils L3 and L4. Similarly, the magnetic coupling between the second coil L2 and the first coil L1 is stronger than the magnetic coupling between the second coil L2 and the other coils L3 and L4. Further, when the coils L1 and L2 other than the third coil L3 and the fourth coil L4, which are one of the two pairs, are used as the other coils L1 and L2, the magnetic coupling between the third coil L3 and the fourth coil L4 Is stronger than the magnetic coupling between the third coil L3 and the other coils L1 and L2. Similarly, the magnetic coupling between the fourth coil L4 and the third coil L3 is stronger than the magnetic coupling between the fourth coil L4 and the other coils L1 and L2.

That is, in the coil component 1A, even if any of the first to fourth coils L1 to L4 is used as a reference, the magnetic coupling between the coil and the coil that is paired is the magnetic coupling between the coil and the coil that is not paired. Stronger than.

Further, due to the symmetry of the structure of the coil component 1A, the magnetic coupling between the first coil L1 and the second coil L2 is as strong as the magnetic coupling between the third coil L3 and the fourth coil L4. Further, the magnetic coupling between the first coil L1 and the fourth coil L4 is as strong as the magnetic coupling between the second coil L2 and the third coil L3, and the magnetic coupling between the first coil L1 and the third coil L3. The magnetic coupling is as strong as the magnetic coupling between the second coil L2 and the fourth coil L4. Therefore, in the coil component 1A, the magnetic coupling between the paired coils is stronger than any of the magnetic couplings between the unpaired coils.

In the coil component 1A, the number of turns, the coil wiring length, and the coil cross-sectional area of the first to fourth coils L1 to L4 are the same. As a result, the deviation of the electrical characteristics (impedance, L value, etc.) of each coil can be reduced. Further, in this case, since one end and the other end of the coils L1 to L4 are arranged so as to be close to each other, the routing of the coils L1 to L4 connected to the external terminals 11a to 14a and 11b to 14b can be minimized. This makes it possible to reduce the size of the coil component 1A. It is not always necessary to satisfy this relationship for all the coils L1 to L4, and the above effect can be exhibited if at least the number of turns of one pair of coils, the coil wiring length, and the coil cross-sectional area are the same. Further, in the above, "same" means manufacturing variation or error with respect to each value of the number of turns, the coil wiring length and the coil cross-sectional area (for example, several% for the number of turns and the coil wiring length, and about 10% for the coil cross-sectional area). ) Degrees of difference are acceptable and include cases where they are substantially the same.

The first coil L1 has two layers, a first spiral wiring 21 wound on the base insulating resin layer 30, a second spiral wiring 22 wound on the first insulating resin layer 31, and a first insulating resin layer. It is composed of via wiring 25 that penetrates 31 in the vertical direction and connects the two layers. The first spiral wiring 21 and the second spiral wiring 22 are arranged in order from the lower layer to the upper layer. The first and second spiral wirings 21 and 22, respectively, are formed by being wound in a plane spiral (spiral) shape. In the first coil L1, the first spiral wiring 21 is wound counterclockwise from the outer circumference toward the inner circumference, and the second spiral wiring 22 is wound counterclockwise from the inner circumference toward the outer circumference. There is. The first and second spiral wirings 21 and 22 and the via wiring 25 are made of, for example, a metal having low electric resistance such as Cu, Ag, and Au. Preferably, Cu plating formed by a semi-additive method can be used to form spiral wiring having low electrical resistance and a narrow pitch.

In the first coil L1, the second spiral wiring 22 is connected to the first spiral wiring 21 via the via wiring 25. Specifically, the via wiring 25 connects the inner peripheral end 21a of the first spiral wiring 21 and the inner peripheral end 22a of the second spiral wiring 22. The outer peripheral end 21b of the first spiral wiring 21 is drawn out to the first side surface 10a side of the prime field 10 and connected to the external terminal 11a. The outer peripheral end 22b of the second spiral wiring 22 is drawn out to the second side surface 10b side of the prime field 10 and connected to the external terminal 11b. From the above, the first coil L1 is counterclockwise from one end to the other end, with the outer peripheral end 21b pulled out to the first side surface 10a side as one end and the outer peripheral end 22b pulled out to the second side surface 10b side as the other end. It is wound around.

Similarly, the second to fourth coils L2 to L4 also have the first spiral wiring 21 wound on the lower insulating layer (base insulating resin layer 30 or the second insulating resin layer 32) and the upper insulating layer (the insulating layer on the upper layer side). Via wiring 25 that penetrates the two layers of the second spiral wiring 22 wound on the first insulating resin layer 31 or the third insulating resin layer 33) in the vertical direction and connects the two layers. Consists of. However, in the second coil L2, the first spiral wiring 21 is wound clockwise from the outer circumference toward the inner circumference, and the second spiral wiring 22 is wound clockwise from the inner circumference toward the outer circumference. There is. Further, in the second coil L2, the via wiring 25 connects the inner peripheral end 21a of the first spiral wiring 21 and the inner peripheral end 22a of the second spiral wiring 22. Further, in the second coil L2, the outer peripheral end 21b (one end) of the first spiral wiring 21 is drawn out to the first side surface 10a side of the prime field 10 and connected to the external terminal 12a. The outer peripheral end 22b (the other end) of the second spiral wiring 22 is drawn out to the second side surface 10b side of the prime field 10 and connected to the external terminal 12b. From the above, the second coil L2 is wound clockwise from one end to the other end. The third coil L3 has the same configuration as the first coil L1, and the outer peripheral end (one end) of the first spiral wiring 21 drawn out to the first side surface 10a side is connected to the external terminal 13a and the second side surface. The outer peripheral end (the other end) of the second spiral wiring 22 drawn out to the 10b side is connected to the external terminal 13b. From the above, the third coil L3 is wound counterclockwise from one end to the other end. The fourth coil L4 has the same configuration as the second coil L2, and the outer peripheral end (one end) of the first spiral wiring 21 drawn out to the first side surface 10a side is connected to the external terminal 14a and the second side surface. The outer peripheral end (the other end) of the second spiral wiring 22 drawn out to the 10b side is connected to the external terminal 14b. From the above, the fourth coil L4 is wound clockwise from one end to the other end.

As described above, in the coil component 1A, one end (outer peripheral end 21b) of the paired first coil L1 and one end (outer peripheral end 21b) of the second coil L2 are relative to the first coil L1 and the second coil L2. It is pulled out to the same first side surface 10a (one side) side. Further, the other end (outer peripheral end 22b) of the first coil L1 and the other end (outer peripheral end 22b) of the second coil L2 have the same second side surface 10b (the other) with respect to the first coil L1 and the second coil L2. ) Is pulled out to the side. Further, the first coil L1 is wound counterclockwise from one end to the other end, and the second coil L2 is wound clockwise from one end to the other end, so that the first coil L1 and the second coil L2 are wound. And are wound in different directions. That is, the first coil L1 and the second coil L2 are wound so that the magnetic fluxes cancel each other when a current flows from one end to the other end. This is because the first coil L1 and the second coil L2 are negative when both ends of the first coil L1 and the second coil L2 are on the input side of the pulse signal and the other ends of each are on the output side of the pulse signal. It means that they are combined.

Therefore, in the coil component 1A, when used in a multi-phase SW regulator, a signal having a phase difference of 180 ° is input to each end of the first coil L1 and the second coil L2 on the same side, so that the first coil component 1A is used. The ripple current of the coil L1 and the second coil L2 can be reduced. In other words, in the first coil L1 and the second coil L2, when a pulse signal is input so as to be negatively coupled, the input side (one end) and the output side (the other end) of the first coil L1 and the second coil L2. Can be aligned on the same side. This makes it possible to easily route the wiring on the board on which the coil component 1A is mounted.
Further, in the coil component 1A, the paired third coil L3 and fourth coil L4 have the same configuration as the first coil L1 and the second coil L2. Therefore, in the coil component 1A, when a pulse signal is input so that the third coil L3 and the fourth coil L4 are negatively coupled, the input side and the output side of the third coil L3 and the fourth coil L4 are on the same side, respectively. Can be aligned with. This makes it possible to easily route the wiring on the board on which the coil component 1A is mounted.

Further, in the coil component 1A, one end and the other end of all of the first to fourth coils L1 to L4 are drawn out to the same side. As a result, in the coil component 1A, when the pulse signal is input so that all the paired coils are negatively coupled, the input side and the output side of the coils L1 to L4 can be aligned on the same side. This makes it easier to route the wiring on the board on which the coil component 1A is mounted.
In the above description, the outer peripheral end 21b is described as one end (pulse signal input side) and the outer peripheral end 22b is described as the other end (pulse signal output side). However, due to the symmetry of the coil component 1A, the outer peripheral end 22b is one end. The outer peripheral end 21b may be the other end.

The base insulating resin layer 30 and the first to fourth insulating resin layers 31 to 34 are arranged in order from the lower layer to the upper layer. The materials of the insulating resin layers 30 to 34 are, for example, a single organic insulating material made of an epoxy resin, bismaleimide, liquid crystal polymer, polyimide, etc., an inorganic filler material such as a silica filler, or an organic material made of a rubber material. It is an insulating material composed of a combination with a filler or the like. Preferably, all the insulating resin layers 30 to 34 are made of the same material. In this embodiment, all the insulating resin layers 30 to 34 are made of a composite material of a silica filler (insulator powder) and an epoxy resin. In this way, when the insulating layer (insulating resin layers 30 to 34) in contact with the spiral wirings 21 and 22 is made of a composite material of insulator powder and resin, the insulation inside the spiral wirings 21 and 22 and between the spiral wirings 21 and 22 The sex can be further improved.

The first insulating resin layer 31 is laminated on the base insulating resin layer 30 so as to cover the first spiral wiring 21 of the first and fourth coils L1 and L4. The second insulating resin layer 32 is laminated on the first insulating resin layer 31 so as to cover the second spiral wiring 22 of the first and fourth coils L1 and L4.

The third insulating resin layer 33 is laminated on the second insulating resin layer 32 so as to cover the first spiral wiring 21 of the second and third coils L2 and L3. The fourth insulating resin layer 34 is laminated on the third insulating resin layer 33 so as to cover the second spiral wiring 22 of the second and third coils L2 and L3.

Here, the via wirings 25 of the coils L1 to L4 are arranged so as not to overlap when viewed from the vertical direction. The location where the via wiring 25 is arranged is also a location where the thickness of the prime field 10 tends to vary in the vertical direction due to the variation in the filling amount of the via wiring 25 in the insulating resin layer. By arranging in, it is possible to reduce the variation in the thickness of the prime field 10. Further, the via wiring 25 of the first coil L1 and the second coil L2 passes through the winding centers of the first and second coils L1 and L2 when viewed from the vertical direction, and reaches the first and second side surfaces 10a and 10b. It is preferable that the coils are arranged so as to be line-symmetrical with respect to the orthogonal straight lines. As a result, the shapes of the first and second coils L1 and L2 that form a pair can be made symmetrical, and the coil component 1A can be manufactured so that these electrical characteristics become uniform. By making the positional relationship between the via wiring 25 of the third coil L3 and the fourth coil L4 the same, the above effect can be obtained for the third and fourth coils L3 and L4.

The outer peripheral ends 21b of the first spiral wiring 21 of the first to fourth coils L1 to L4 are arranged in order along the long side direction (direction perpendicular to the vertical direction) of the first side surface 10a. That is, the external terminals 11a to 14a on the first side surface 10a side are arranged in order along the long side direction of the first side surface 10a.

The outer peripheral ends 22b of the second spiral wirings 22 of the first to fourth coils L1 to L4 are arranged in order along the long side direction (direction perpendicular to the vertical direction) of the second side surface 10b. That is, the external terminals 11b to 14b on the second side surface 10b side are arranged in order along the long side direction of the second side surface 10b.

In this way, the first external terminal 11 connected to the first coil L1 and the second external terminal 12 connected to the second coil L2 are arranged adjacent to each other and connected to the third coil L3. The external terminal 13 and the fourth external terminal 14 connected to the fourth coil L3 are arranged next to each other. In the coil component 1A, the paired first coil L1 and the second coil L2 are arranged in the vertical direction, and their outer peripheral ends 21b and 22b are relatively close to each other. Therefore, since the first external terminal 11 and the second external terminal 12 to which the outer peripheral ends 21b and 22b are connected are also located close to each other, the wiring connected to the external terminals 11 and 12 of the first coil L1 and the second coil L2 is routed. Can be shortened. Since the paired third coil L3 and the fourth coil L4 have the same configuration, the wiring connected to the respective external terminals 13 and 14 can be shortened. As a result, the outer shape of the coil component 1A can be reduced in size. Further, in the coil component 1A, the arrangement order of the external terminals 11a to 14a on the first side surface 10a and the arrangement order of the external terminals 11b to 14b on the second side surface 10b match. As a result, in the board on which the coil component 1A is mounted, the arrangement order of the wiring on the input side and the arrangement order of the wiring on the output side can be matched, and the mounting becomes easy. Therefore, it is possible to provide the coil component 1A which is small and easy to mount.

A plurality of spiral wirings 21, in which the first coil L1 and the second coil L2 are respectively wound on a plurality of insulating layers (insulating resin layers 30, 31 or insulating resin layers 32, 33) as in the coil component 1A. When composed of 22, preferably, the shortest distance between the first coil L1 and the second coil L2 is the shortest distance between the spiral wirings 21 and 22 in the first coil L1 and the second coil L2, respectively. Longer than. As a result, in the combination of pulse signals that can reduce the ripple current of the coils L1 and L2, the insulation between the first coil L1 and the second coil L2, in which the period in which the different voltage is applied is relatively long, is relatively improved. This makes it possible to improve the reliability of the coil component 1A. The same applies to the third coil L3 and the fourth coil L4.

Further, as in the coil component 1A, the spiral wiring (for example, the first spiral wiring 21) of a plurality of coils (for example, the first coil L1 and the fourth coil L4) is provided on the same insulating layer (for example, the base insulating resin layer 30). When wound, preferably, the wiring interval between the spiral wirings (for example, the interval between the spiral wirings 21 of the first coil L1 and the fourth coil L4) is longer than the wiring interval in the spiral wiring. As a result, the insulation between the spiral wirings wound on the same insulating layer of the adjacent coils having a period in which the different voltage is applied can be relatively improved, and the reliability can be improved.

The insulating resin 35 has a first hole portion 35a centered on the shafts of the first coil L1 and the second coil L2, and a second hole portion 35b centered on the shafts of the third coil L3 and the fourth coil L4. ..

The magnetic resin 40 is made of a composite material of magnetic powder and resin. The magnetic powder is, for example, a metallic magnetic material made of a FeSi, FeCo, FeAl-based alloy or an amorphous material, and the resin is, for example, a resin material such as epoxy. That is, in the coil component 1A, the insulating layers on both sides in the vertical direction with respect to the spiral wirings 21 and 22 of the first to fourth coils L1 to L4 include a magnetic resin layer 42 made of a composite material of magnetic powder and resin. .. As a result, the density of the magnetic flux generated by the first coils L1 to L4 is improved by the magnetic resin layer 42, and the coil component 1A capable of ensuring an appropriate inductance and coupling coefficient while being compact and thin can be provided at low cost. can.

Further, in the coil component 1A, the magnetic resin bodies 41a and 41b provided in the inner diameter portions (first and second hole portions 35a and 35b) of the coils L1 to L4 with respect to the first to fourth coils L1 to L4, respectively. , And a magnetic resin body 41c provided outside the outermost periphery of the spiral wirings 21 and 22 of the coils L1 to L4. As described above, the magnetic resin bodies 41a, 41b, and 41c are made of a composite material of magnetic powder and resin. Here, in the coil component 1A, the magnetic resin layer 42 and the magnetic resin bodies 41a and 41c are connected to the first and second coils L1 and L2, so that the third and fourth coils L3 and L4 are connected. The magnetic resin layer 42 and the magnetic resin bodies 41b and 41c are connected to each other to form a closed magnetic path. As a result, the leakage flux from the coils L1 to L4 can be reduced, noise can be suppressed, and the magnetic coupling between the paired coils L1 and L2 and the magnetic coupling between the coils L3 and L4 are strengthened. , It is possible to weaken the magnetic coupling between the other coils that do not form a pair.

The average particle size of the magnetic powder is preferably 0.5 μm or more and 100 μm or less, whereby the magnetic resin can be made into a small core. Further, the magnetic powder is preferably contained in an amount of 50 vol% or more and 85 vol% or less with respect to the resin, whereby a sufficient magnetic permeability can be obtained and the magnetic bond between the paired coils is strengthened. Can be done.

In order to improve the characteristics (inductance value and superimposition characteristics) of the coil component 1A, it is desirable that the magnetic powder is contained in an amount of 70 vol% or more, and in order to improve the filling property of the magnetic resin 40, the particle size distribution is different. It is even better to mix two or three types of magnetic powder. Further, in order to ensure that the magnetic powder is filled in the first and second pores 35a and 35b of the insulating resin 35, the average particle size of the magnetic powder is higher than that of the first and second pores 35a and 35b. Smaller is preferable, and 40 μm or less is preferable. Further, in the application of the coil component 1A, when the operating frequency is high, for example, 40 MHz or more, the magnetic material powder may be a single magnetic filler having a particle size distribution having an average particle size of 1 μm or less.

In the coil component 1A, as shown in FIG. 3, it is preferable that the portion having the minimum distance between the first coil L1 and the fourth coil L4 is not filled with the third magnetic resin body 41c. As a result, the coupling between the first coil L1 and the fourth coil L4 can be relatively weakened. Further, since the magnetic resin 40 is made of a resin containing a metal and has inferior pressure resistance as compared with the insulating resin 35, it is reliable to fill the minimum distance between the first coil L1 and the fourth coil L4 with the magnetic resin 40. From the viewpoint of property, it is necessary to sufficiently separate the first coil L1 and the fourth coil L4, which increases the external size of the coil component 1A. Therefore, the reliability of the coil component 1A can be improved in the same outer shape by not filling the portion having the minimum distance between the first coil L1 and the fourth coil L4 with the third magnetic resin body 41c. The same applies between the second coil L2 and the third coil L3.

As an example of the coil component 1A, the thickness of the spiral wiring 21 and 22 is 45 μm, the width of the spiral wiring 21 and 22 is 60 μm, the wiring interval in the spiral wiring 21 and 22 is 10 μm, and the spiral wiring 21 and The thickness of the insulating resin between the spiral wiring 22 and the spiral wiring 22 is 10 μm. The external size of the coil component 1A is width 2.0 mm × depth 1.2 mm × height 0.85 mm, the inductance value of each coil L1 to L4 of the coil component 1A is 74 nH, and the coupling coefficient between the paired coils is 0. It is 8.8.

Next, a method of manufacturing the coil component 1A will be described with reference to FIGS. 5A to 5R.

As shown in FIG. 5A, the base 50 is prepared. The base 50 has an insulating substrate 51 and a base metal layer 52 provided on both sides of the insulating substrate 51. In this embodiment, the insulating substrate 51 is a glass epoxy substrate, the base metal layer 52 is a Cu foil, and its main surface is a smooth surface.

Then, as shown in FIG. 5B, the dummy metal layer 60 is adhered on one surface of the base 50. In this embodiment, the dummy metal layer 60 is a Cu foil. Since the dummy metal layer 60 is adhered to the base metal layer 52 of the base 50, the dummy metal layer 60 is adhered to the smooth surface of the base metal layer 52. Therefore, the adhesive force between the dummy metal layer 60 and the base metal layer 52 can be weakened, and the base 50 can be easily peeled off from the dummy metal layer 60 in a later step. Preferably, the adhesive for adhering the base 50 and the dummy metal layer 60 is a low adhesive adhesive. Further, in order to weaken the adhesive force between the base 50 and the dummy metal layer 60, it is desirable that the adhesive surface between the base 50 and the dummy metal layer 60 be a glossy surface.

After that, the base insulating resin layer 30 is laminated on the dummy metal layer 60 temporarily fixed to the base 50. At this time, the base insulating resin layer 30 is laminated by a vacuum laminator and then heat-cured.

Then, as shown in FIG. 5C, through holes 30a, 30d, 30e, 30f are formed in a part of the base insulating resin layer 30 to expose the dummy metal layer 60. The through holes 30a, 30d, 30e, and 30f are formed by laser processing, and the through holes 30a form a magnetic resin body 41a, the through holes 30d form a magnetic resin body 41b, and the through holes 30e and 30f form a magnetic resin body 41c, respectively. Formed at the filling site.

Then, as shown in FIG. 5D, the first spiral wiring layer 3a and the first spiral wiring layer 3b are formed in the base insulating resin layer 30 surrounding the through holes 30a and 30d. At this time, the first spiral wiring layers 3a and 3b are simultaneously formed by the semi-additive method. The first spiral wiring layer 3a constitutes the first spiral wiring 21 of the first coil L1, and the first spiral wiring layer 3b constitutes the first spiral wiring 21 of the fourth coil L4. At this time, a wiring layer is also formed on the base insulating resin layer 30 in and around the through holes 30a, 30d, 30e, and 30f.

Then, as shown in FIG. 5E, the first spiral wiring layers 3a and 3b are covered with the first insulating resin layer 31. At this time, the first insulating resin layer 31 is laminated on the base insulating resin layer 30 with a vacuum laminator and then thermally cured.

Then, as shown in FIG. 5F, through holes 31a, 31d, 31e, 31f and via holes 31b, 31c are formed in the first insulating resin layer 31 by laser processing. The through holes 31a, 31d, 31e, and 31f are formed in the first insulating resin layer 31 above the through holes 30a, 30d, 30e, and 30f, respectively.

The via holes 31b and 31c are positions where the first spiral wiring layers 3a and 3b and the second wiring layer formed next are electrically connected in series, specifically, the inner circumference of the first spiral wiring 21. It is formed on the first insulating resin layer 31 on the portion to be the end 21a. Here, the through holes 31a, 31d, 31e, 31f and the via holes 31b, 31c can be simultaneously machined to simplify the process.

Then, as shown in FIG. 5G, the second spiral wiring layers 5a and 5b are formed on the first insulating resin layer 31 surrounding the through holes 31a and 31d by the same semi-additive method as the first spiral wiring layers 3a and 3b. .. At this time, a part of the second spiral wiring layer 5a is filled in the via hole 31b to form a portion to be the via wiring 25, and the first spiral wiring layer 3a and the second spiral wiring layer 5a are electrically connected. Let me. Similarly, for the second spiral wiring layer 5b, a portion to be the via wiring 25 is formed in the via hole 31c and electrically connected to the first spiral wiring layer 3b. The second spiral wiring layers 5a and 5b constitute the second spiral wiring 22 of the first coil L1 and the fourth coil L4, respectively. As a result, the first coil L1 and the fourth coil L4 can be formed. At this time, a wiring layer is also formed on the first insulating resin layer 31 in and around the through holes 31a, 31d, 31e, and 31f.

Then, as shown in FIG. 5H, the second spiral wiring layers 5a and 5b are covered with the second insulating resin layer 32. At this time, the second insulating resin layer 32 is laminated on the first insulating resin layer 31 with a vacuum laminator and then thermally cured.

Then, as shown in FIG. 5I, through holes 32a, 32d, 32e, 32f are formed in the second insulating resin layer 32 by laser processing. The through holes 32a, 32d, 32e, and 32f are formed in the second insulating resin layer 32 above the through holes 31a, 31d, 31e, and 31f, respectively.

Then, as shown in FIG. 5J, the first spiral wiring layer 7a and the first spiral wiring layer are placed on the second insulating resin layer 32 surrounding the through holes 32a and 32d by the same semi-additive method as the first spiral wiring layer 3a. Form 7b. The first spiral wiring layers 7a and 7b constitute the first spiral wiring 21 of the second coil L2 and the third coil L3, respectively. At this time, a wiring layer is also formed on the second insulating resin layer 32 in and around the through holes 32a, 32d, 32e, 32f.

Then, as shown in FIG. 5K, the first spiral wiring layers 7a and 7b are covered with the third insulating resin layer 33. At this time, the third insulating resin layer 33 is laminated on the second insulating resin layer 32 with a vacuum laminator and then thermally cured.

Then, as shown in FIG. 5L, through holes 33a, 33d, 33e, 33f and via holes 33b, 33c are formed in the third insulating resin layer 33 by laser processing. The through holes 33a, 33d, 33e, 33f are formed in the third insulating resin layer 33 above the through holes 32a, 32d, 32e, 32f, respectively. The via holes 33b and 33c are positions where the first spiral wiring layers 7a and 7b and the wiring layer to be formed next are electrically connected in series, specifically, the inner peripheral end 21a of the first spiral wiring 21. It is formed on the third insulating resin layer 33 on the portion.

Then, as shown in FIG. 5M, the second spiral wiring layers 9a and 9b are formed on the third insulating resin layer 33 surrounding the through holes 33a and 33d by the same semi-additive method as the first spiral wiring layers 7a and 7b. .. At this time, a part of the second spiral wiring layer 9a is filled in the via hole 33b to form a portion to be the via wiring 25, and the first spiral wiring layer 7a and the second spiral wiring layer 9a are electrically connected. Let me. Similarly, for the second spiral wiring layer 9b, a portion to be the via wiring 25 is formed in the via hole 33c and electrically connected to the first spiral wiring layer 7b. The second spiral wiring layers 9a and 9b form the second spiral wiring 22 of the second coil L2 and the third coil L3, respectively. As a result, the second coil L2 and the third coil L3 can be formed. At this time, a wiring layer is also formed on the third insulating resin layer 33 in and around the through holes 33a, 33d, 33e, 33f.

Then, as shown in FIG. 5N, the second spiral wiring layers 9a and 9b are covered with the fourth insulating resin layer 34. At this time, the fourth insulating resin layer 34 is laminated on the third insulating resin layer 33 with a vacuum laminator and then thermally cured.

Then, as shown in FIG. 5O, through holes 34a, 34d, 34e, 34f are formed in the fourth insulating resin layer 34 by laser processing. The through holes 34a, 34d, 34e, and 34f are formed in the fourth insulating resin layer 34 above the through holes 33a, 33d, 33e, and 33f, respectively.

Then, as shown in FIG. 5P, the base 50 is peeled off from the dummy metal layer 60 at the adhesive surface between one surface of the base 50 (base metal layer 52) and the dummy metal layer 60.

Then, as shown in FIG. 5Q, the dummy metal layer 60 is removed by etching. At this time, the wiring layers provided in the through holes 30a to 34a, 30d to 34d, 30e to 34e, and 30f to 31f of the insulating resin layers 30 to 34 are simultaneously etched, and the inner magnetic path and the outer magnetic path of the coil are etched. The space that forms the is formed. In this way, the coil substrate 2 having the coils L1 to L4 is formed.

Then, as shown in FIG. 5R, a plurality of sheets of magnetic powder and resin composite materials molded into a sheet shape are arranged on the upper and lower sides of the coil substrate 2, heat-pressed by a vacuum laminator or a vacuum press, and then cured. Do the processing. At this time, the space forming the inner magnetic path and the outer magnetic path is filled with the composite material, and the magnetic resin 40 including the magnetic resin bodies 41a and 41b corresponding to the inner magnetic path and the magnetic resin layer 42 corresponding to the outer magnetic path is provided. Form. After that, it is cut with a dicer or the like and separated into individual pieces. At this time, the cut surfaces of the first and second spiral wiring layers 3a, 3b, 5a, 5b, 7a, 7b, 9a, 9b corresponding to the outer peripheral ends 21b, 22b of the first and second spiral wirings 21 and 22 are cut. Expose from. Further, by forming the external terminals 11a to 14a and 11b to 14b so as to be connected to the wiring layer exposed on the cut surface, the coil component 1A shown in FIG. 2 can be obtained.

In the above, the coil substrate 2 is formed on one of both sides of the base 50, but the coil substrate 2 may be formed on each of the both sides of the base 50. Further, in the above, one coil substrate 2 is formed on one surface of the base 50, but after forming a plurality of coil substrates 2 in a matrix on one surface of the base 50, a plurality of coil substrates 2 are formed into individual sides. The coil component 1A may be formed at the same time. High productivity can be obtained by these methods. Further, the above manufacturing method is merely an example of the manufacturing method of the coil component 1A, and other known construction methods and techniques may be applied as long as the same configuration can be obtained.

According to the coil component 1A, the magnetic coupling between the paired first coil L1 and the second coil L2 is stronger than the magnetic coupling between the unpaired first coil L1 and the third and fourth coils L3 and L4. .. Thereby, similarly to the coil component 1 according to the first embodiment, when the coil component 1A is used for the multi-phase SW regulator, the pulse signal input to each coil L1 to L4 is appropriately selected to obtain the first pulse signal. The ripple current of the coil L1 can be reduced.

Further, in the coil component 1A, even if any of the first to fourth coils L1 to L4 is used as a reference, the magnetic coupling between the coil and the coil that is paired with the coil is the magnetic coupling between the coil and the coil that is not paired with the coil. Stronger than. Thereby, similarly to the coil component 1 according to the first embodiment, when the coil component 1A is used for the multi-phase SW regulator, the pulse signal input to each coil L1 to L4 is appropriately selected to obtain the first pulse signal. The ripple current of the fourth coils L1 to L4 can be reduced.

Here, in order to appropriately select a pulse signal so as to reduce the ripple current of the first to fourth coils L1 to L4, for example, it is 180 ° as compared with the signal input to the first coil L1. A signal having a phase difference is input to the second coil L2, a signal having a phase difference of 90 ° compared to the signal input to the first coil L1 is input to the third coil L3, and is input to the first coil L1. A signal having a phase difference of 270 ° as compared with the signal may be input to the fourth coil L4.

Further, in the coil component 1A, the first external terminal 11 connected to the first coil L1 and the second external terminal 12 connected to the second coil L2 are adjacent to each other and are connected to the third coil L3. The 3 external terminals 13 and the 4th external terminal 14 connected to the 4th coil L4 are adjacent to each other. In the coil component 1A, the distance between the first coil L1 and the second coil L2 is shorter than the distance between the first coil L1 and the other coils L3 and L4 due to the strength of the magnetic coupling, and the distance between the first coil L1 and the second coil L1 The two coils L2 are arranged close to each other. Therefore, the first and second external terminals 11 and 12 connected to the pair of coils L1 and L2 arranged close to each other are adjacent to each other, so that the coils L1 and L2 and the external terminals 11 and 12 in the coil component 1A are adjacent to each other. The routing between can be reduced. As a result, the coil component 1A can be miniaturized. In the coil component 1A, the third and fourth external terminals 13 and 14 connected to the other pair of the third and fourth coils L3 and L4 have the same configuration, so that the coil component 1A is further miniaturized. can.

Hereinafter, it will be described that the ripple current of each coil L1 to L4 can be actually reduced by the evaluation performed by the inventor of the present application using the example of the coil component 1A.

Table 1 shows the configurations, evaluation conditions, and evaluation results of the present example and comparative examples 1 and 2. Both the present embodiment and Comparative Examples 1 and 2 have four coils L1 to L4 as coil parts. The inductance values of the coils L1 to L4 are 1 μH, respectively. This embodiment has the configuration of the coil component 1A shown in FIGS. 2 to 4, and is configured such that the coil L1 and the coil L2 and the coil L3 and the coil L4 are paired with each other. Comparative Example 1 is a coil component in which the four coils L1 to L4 are not magnetically coupled to each other. Comparative Example 2 has the configuration of the coil component shown in Patent Document 1, and specifically, as shown in FIG. 6, each of the four spokes 101 of the wheel type core 100 has four coils. It has a configuration in which L1 to L4 are wound.

[Table 1]

As shown in Table 1, in Comparative Example 1, the coupling coefficients of the four coils L1 to L4 are 0. In Comparative Example 2, the four coils L to L4 are strongly magnetically coupled to each other, and in particular, the magnetic coupling between the coils that are not aligned on the same straight line in FIG. 6 (for example, the magnetic coupling between the coil L1 and the coil L2 and the coil L1). The magnetic coupling with the coil L4) is equal and the coupling coefficient is −0.399. Even among the coils arranged on the same straight line in FIG. 6 (for example, coil L1 and coil L3 and coil L2 and coil L4), the coupling coefficient is −0.193. The coupling coefficient of Comparative Example 2 is calculated from the result of 3D magnetic field analysis by the magnetic field analysis software Femtet (manufactured by Murata Software Co., Ltd.).

On the other hand, in this embodiment, the coupling coefficient between the paired coil L1 and the coil L2 and the coupling coefficient between the paired coil L3 and the coil L4 are −0.9, and no other pair is formed. The coupling coefficient of the coil combination is −0.1. That is, the magnetic coupling between the paired coil L1 and the coil L2 and the magnetic coupling between the coil L3 and the coil L4 are stronger than the magnetic coupling between the unpaired coils. Comparative Examples 1 and 2 do not satisfy the strength relationship of this magnetic bond.

Then, in the present embodiment and Comparative Examples 1 and 2, with respect to the pulse signal input to the coil L1, the coil L2 has a pulse signal having a phase difference of 180 °, and the coil L3 has a phase difference of 90 °. A pulse signal having a phase difference of 270 ° was input to the coil L4, and a pulse signal having a phase difference of 270 ° was input to the coil L4. At this time, the relationship between the input voltage [V] and the coil current [A], which are pulse signals input to the coils L1 to L4, is shown in FIGS. 7 to 9. 7 shows the present embodiment, FIG. 8 shows Comparative Example 1, and FIG. 9 shows Comparative Example 2. In the figure, (a) shows the first coil L1, (b) shows the second coil L2, (c) shows the third coil L3, and (d) shows the fourth coil L4. In the figure, the square wave indicates the input voltage, and the polygonal line indicates the coil current. The coil current was calculated by LTSPICE. In addition, the waveform data shown in FIGS. 7 to 9 are organized in Table 1.

As shown in Table 1, in this embodiment, the ripple currents of the coils L1 to L4 are reduced by about 30% and the ripple effective value is reduced by about 69% as compared with Comparative Example 1 which is uncoupled. The ripple effective value is a value obtained by subtracting the average value of the coil current from the effective value of the coil current. Further, in this embodiment, the ripple currents of the coils L1 to L4 are reduced by about 58% and the effective ripple value is reduced by about 76% as compared with Comparative Example 2. Therefore, in this embodiment, it can be seen that the ripple currents of the coils L1 to L4 can be made smaller than those of Comparative Examples 1 and 2. In Comparative Example 2, the ripple current is increased by about 66% and the ripple effective value is increased by about 31% as compared with Comparative Example 1 which is uncoupled. That is, it is shown by this evaluation that the coil component described in Patent Document 1 may have a larger ripple current than the uncoupled coil component.

(Third Embodiment)
FIG. 10A is an exploded perspective view showing the coil component 1B according to the third embodiment. FIG. 10B is a cross-sectional view showing the coil component 1B. The third embodiment differs from the second embodiment in the number of layers of the spiral wiring constituting each coil. This different configuration will be described below. In the third embodiment, the same reference numerals as those in the second embodiment have the same configuration as those in the second embodiment, and thus the description thereof will be omitted.

As shown in FIGS. 10A and 10B, in the coil component 1B, the first to fourth coils L1 to L4 are each composed of a one-layer spiral wiring 21, a via wiring 25, and a lead wiring 75. The leader wiring 75 is linear and is not a spiral wiring.

The insulating resin 35 is composed of a base insulating resin layer 30 and first, second, and third insulating resin layers 31, 32, 33. The spiral wirings 21 of the first and fourth coils L1 and L4 are arranged on the base insulating resin layer 30, and the extraction wirings 75 of the first to fourth coils L1 to L4 are arranged on the first insulating resin layer 31. The spiral wiring 21 of the third coils L2 and L3 is covered on the second insulating resin layer 32 by the first insulating resin layer 31, the second insulating resin layer 32, and the third insulating resin layer 33, respectively.

The positional relationship between the first to fourth coils L1 to L4 in the coil component 1B is the same as that of the coil component 1A. Therefore, the magnetic coupling between the first coil L1 and the second coil L2 that form a pair is the magnetic coupling between the first coil L1 and the third coil L3 and the fourth coil L3 and L4 that do not form a pair, and the second coil L2 and the third coil. It is stronger than the magnetic coupling with the fourth coils L3 and L4. Further, the magnetic coupling between the third coil L3 and the fourth coil L4 that form a pair is the magnetic coupling between the third coil L3 and the first coil L1 and the second coil L1 and L2 that do not form a pair, and the fourth coil L4 and the first coil. It is stronger than the magnetic coupling with the second coils L1 and L2.

In the coil component 1B, the inner peripheral end 21a of the spiral wiring 21 of the first to fourth coils L1 to L4 is the first via the via wiring 25 provided in the first insulating resin layer 31 or the second insulating resin layer 32. 1 It is connected to the lead wiring 75 of each coil L1 to L4 provided on the insulating resin layer 31. The lead wiring 75 extends linearly from the connection portion with the via wiring 25 in the side surface direction of the prime field 10 and is connected to the corresponding first to fourth external terminals 11a to 14a and 11b to 14b. The outer peripheral end 21b of the spiral wiring 21 of the first coils L1 to L4 is drawn out to the side surface of the prime field 10 and corresponds to the corresponding first to fourth external terminals 11a, similarly to the coil component 1A according to the second embodiment. It is connected to ~ 14a, 11b ~ 14b.

In the above, the lead wiring 75 is on the first insulating resin layer 31, that is, between the layer provided with the spiral wiring 21 of the coils L1 and L4 and the layer provided with the spiral wiring 21 of the coils L2 and L3. Although it is provided, the leader wiring 75 is not limited to this configuration. The lead wiring 75 may be provided, for example, below the layer provided with the spiral wiring 21 of the coils L1 and L4, or above the layer provided with the spiral wiring 21 of the coils L2 and L3.

In the coil component 1B, when one of the coils L1 to L4 is the first coil, the coil paired with the first coil is the second coil, and the coils other than the first coil and the second coil are the other coils, the first coil is used. The magnetic coupling between the 1st coil and the 2nd coil is stronger than the magnetic coupling between the 1st coil and the other coils. Therefore, even in the coil component 1B, when used in the polyphase SW regulator, the ripple current of each coil L1 to L4 can be reduced by appropriately selecting the pulse signal input to each coil L1 to L4. Further, in the coil component 1B, since each coil L1 to L4 is composed of one layer of spiral wiring 21, the coil component 1B can be made low in height.

(Fourth Embodiment)
FIG. 11A is an exploded perspective view showing the coil component 1C according to the third embodiment. FIG. 11B is a cross-sectional view showing the coil component 1C. The fourth embodiment is different from the third embodiment in the configuration of the extraction portion of the coils L1 to L4 to the external terminals. This different configuration will be described below. In the fourth embodiment, the same reference numerals as those in the third embodiment have the same configuration as those in the third embodiment, and thus the description thereof will be omitted.

As shown in FIGS. 11A and 11B, in the coil component 1C, the inner peripheral ends 21a of the spiral wirings 21 of the first to fourth coils L1 to L4 are primed by the first to fourth columnar electrodes 71 to 74. It is pulled out to the upper surface of 10. Although not shown, in the coil component 1C, a part of the external terminal is provided on the upper surface side of the prime field 10, and the columnar electrodes 71 to 74 of the coils L1 to L4 correspond to the outer surface on the upper surface side. Connected to the terminal. The first to fourth columnar electrodes 71 to 74 are made of, for example, a metal having low electric resistance such as Cu, Ag, and Au, and are formed by, for example, a semi-additive method. The outer peripheral ends 21b of the spiral wirings 21 of the first to fourth coils L1 to L4 are drawn out to the side surface of the prime field 10 and connected to the corresponding external terminals as in the third embodiment. Hereinafter, the internal structure of the coil component 1C will be described in more detail.

The inner peripheral end 21a of the spiral wiring 21 of the first and fourth coils L1 and L4 is a lead wiring provided on the first insulating resin layer 31 via the via wiring 25 provided on the first insulating resin layer 31. Connected to 75. The lead wiring 75 of the first and fourth coils L1 and L4 is provided on the second insulating resin layer 32 and in the magnetic resin 40 via the via wiring 25 provided in the second insulating resin layer 32. , 4th columnar electrodes 71 and 74, respectively.

The inner peripheral end 21a of the spiral wiring 21 of the second and third coils L2 and L3 is provided on the second insulating resin layer 32 and on the magnetic resin 40 via the via wiring 25 provided on the second insulating resin layer 32. It is connected to the second and third columnar electrodes 72 and 73.

The positional relationship between the first to fourth coils L1 to L4 in the coil component 1C is the same as that of the coil component 1A. Therefore, the magnetic coupling between the first coil L1 and the second coil L2 that form a pair is the magnetic coupling between the first coil L1 and the third coil L3 and the fourth coil L3 and L4 that do not form a pair, and the second coil L2 and the third coil. It is stronger than the magnetic coupling with the fourth coils L3 and L4. Further, the magnetic coupling between the third coil L3 and the fourth coil L4 that form a pair is the magnetic coupling between the third coil L3 and the first coil L1 and the second coil L1 and L2 that do not form a pair, and the fourth coil L4 and the first coil. It is stronger than the magnetic coupling with the second coils L1 and L2.

That is, in the coil component 1C, when one of the coils L1 to L4 is the first coil, the coil paired with the first coil is the second coil, and the coils other than the first coil and the second coil are the other coils. , The magnetic coupling between the first coil and the second coil is stronger than the magnetic coupling between the first coil and the other coils. Therefore, even in the coil component 1C, when used in a polyphase SW regulator, the ripple current of each coil L1 to L4 can be reduced by appropriately selecting the pulse signal input to each coil L1 to L4.

Further, in the coil component 1C, one end of each of the first to fourth coils L1 to L4 is pulled out to the upper surface of the prime field 10 by the first to fourth columnar electrodes 71 to 74, so that the coil component 1B As described above, it is not necessary to form a wiring layer other than the spiral wiring 21, and the height can be further reduced. Further, in the coil component 1C, a part of the external terminal is provided on the upper surface side of the prime field 10. For example, the external terminal can be extended from the upper surface side to the side surface side or the bottom surface side, and in this case, surface mounting is possible. It becomes. Further, for example, even when the external terminal is provided only on the upper surface of the prime field 10, the coil component 1C is embedded in the mounting board for three-dimensional mounting, so that the mounting board can be mounted from the upper surface of the prime field 10. It is also possible to connect directly to the wiring pattern of. Further, at this time, the wiring pattern of the mounting board and the first to fourth columnar electrodes 71 to 74 may be directly connected without providing the external terminal.

(Fifth Embodiment)
12A is a perspective perspective view showing the coil component 1D according to the fifth embodiment, FIG. 12B is a sectional view taken along the line XX of FIG. 12A, and FIG. 12C is a perspective top view showing the coil component 1D. .. The coil component 1D is different from the coil component 1C of the fourth embodiment in the shape of the spiral wiring constituting each coil L1 to L4. This different configuration will be mainly described below. In the fifth embodiment, the same reference numerals as those of the first to fourth embodiments have the same configuration as those of the embodiment, and thus the description thereof will be omitted.

As shown in FIG. 12A, in the coil component 1D, the first to fourth coils L1 to L4 are each composed of one layer of spiral wiring 23D. Further, as shown in FIG. 12B, the spiral wirings 23D of the first and fourth coils L1 and L4 are provided on the base insulating resin layer 30 and covered with the first insulating resin layer 31. The second and third coils L2 and L3 are provided on the first insulating resin layer 31 and are covered with the second insulating resin layer 32. That is, the spiral wiring 23D is arranged inside the prime field 10. Further, as shown in FIG. 12C, the spiral wiring 23D has a semi-elliptical arc shape when viewed from above and below. That is, the spiral wiring 23D is a curved wiring wound about half a circumference on the base insulating resin layer 30 or the first insulating resin layer 31 (on the insulating layer). The number of turns of the spiral wiring 23D is not limited to about half a turn, and may be any number less than one turn. As described above, when the number of turns is less than one turn, both ends of the spiral wiring 23D are the outermost circumferences (the inner peripheral portion surrounded by itself is not formed), so that the three-dimensional wiring by the via wiring can be unnecessary.

The spiral wiring 23D of the first coil L1 has both ends 23a and 23b connected to the first external terminals 11a and 11b, and has a curved shape that draws an arc from the external terminals 11a and 11b toward the center side of the coil component 1D. .. The spiral wiring 23D of the third coil L3 has the same shape as the spiral wiring 23D of the first coil L1, and both ends 23a and 23b thereof are connected to the third external terminals 13a and 13b.

The spiral wiring 23D of the second coil L2 has both ends 23a and 23b connected to the second external terminals 12a and 12b, and has a curved shape that draws an arc from the external terminals 12a and 12b toward the edge side of the coil component 1D. The spiral wiring 23D of the fourth coil L4 has the same shape as the spiral wiring 23D of the second coil L2, and both ends 23a and 23b thereof are connected to the fourth external terminals 14a and 14b.

Here, in the coil component 1D, each of the coils L1 to L4 is surrounded by the inside of the innermost circumference of the spiral wiring 23D (the curve of the spiral wiring 23D and the straight line connecting both ends 23a and 23b of the spiral wiring 23D). Range) is the inner diameter part. At this time, in the coil component 1D, the inner diameter portion of the first coil L1 and the inner diameter portion of the second coil L2 overlap each other when viewed from the vertical direction, and the inner diameter portion of the first coil L3 and the inner diameter portion of the fourth coil L4 Overlap each other. Further, the inner diameter portion of the first coil L1 and the inner diameter portions of the third and fourth coils L3 and L4 do not overlap each other, and the inner diameter portion of the second coil L1 and the inner diameter portions of the third and fourth coils L3 and L4 do not overlap with each other. Do not overlap each other.

That is, in the coil component 1D, the first coil L1 and the second coil L2 form a pair, and the third coil L3 and the fourth coil L4 form a pair, as in the coil component 1 of the first embodiment. The coils L1 to L4 are configured to form two pairs. Further, the magnetic coupling between the paired first coil L1 and the second coil L2 is such that the magnetic coupling between the unpaired first coil L1 and the third and fourth coils L3 and L4 and the second coil L2 and the third coil. It is stronger than the magnetic coupling with the fourth coils L3 and L4. Further, the magnetic coupling between the third coil L3 and the fourth coil L4 that form a pair is the magnetic coupling between the third coil L3 and the first coil L1 and the second coil L1 and L2 that do not form a pair, and the fourth coil L4 and the first coil. It is stronger than the magnetic coupling with the second coils L1 and L2. Actually, in the configuration of the coil component 1D, the wiring width of the spiral wiring 23D is 50 μm, the wiring thickness is 45 μm, the minimum wiring interval is 10 μm, and the minimum spacing between layers is 10 μm, and the calculation of the 3D magnetic field analysis result using the magnetic field analysis software Femtet is used. Was done. As a result, the absolute value of the coupling coefficient between the paired first coil L1 and the second coil L2 is the absolute value of the coupling coefficient between the first coil L1 and the fourth coil L4 adjacent to each other on the base insulating resin layer 30. It was more than 1.5 times that of. Further, the absolute value of the coupling coefficient between the first coil L1 and the third coil L3, in which the layers provided are different and the distance between the inner diameter portions is large, is smaller than the absolute value of the coupling coefficient.

Therefore, in the coil component 1D, when one of the coils L1 to L4 is the first coil, the coil paired with the first coil is the second coil, and the coils other than the first coil and the second coil are the other coils. , The magnetic coupling between the first coil and the second coil is stronger than the magnetic coupling between the first coil and the other coils. Therefore, even in the coil component 1D, when used in a polyphase SW regulator, the ripple current of each coil L1 to L4 can be reduced by appropriately selecting the pulse signal input to each coil L1 to L4. Further, in the coil component 1D, since each coil L1 to L4 is composed of one layer of spiral wiring 23D, the height of the coil component 1D can be reduced. Further, unlike the coil component 1B of the third embodiment, it is not necessary to form a wiring layer other than the spiral wiring 23D, and the height can be further reduced.

(Sixth Embodiment)
13A is a perspective perspective view showing the coil component 1E according to the sixth embodiment, FIG. 13B is a sectional view showing the coil component 1E, and FIG. 13C is a perspective top view showing the coil component 1E. The coil component 1E is different from the coil component 1D of the fifth embodiment in that the shapes of the coils L1 to L4 and the layers provided are different, and the coil components 1E are provided with the first to fourth columnar electrodes 71a to 74a and 71b to 74b. It's different. This different configuration will be mainly described below. In the sixth embodiment, the same reference numerals as those of the first to fifth embodiments have the same configuration as those of the embodiment, and thus the description thereof will be omitted.

As shown in FIG. 13A, in the coil component 1E, the first to fourth coils L1 to L4 are composed of a single layer spiral wiring 23E and a leader wiring 75E, respectively. Further, as shown in FIG. 13B, the first to fourth coils L1 to L4 are all provided on the base insulating resin layer 30 and covered with the first insulating resin layer 31. Further, as shown in FIG. 13C, both ends of the spiral wiring 23E are connected to the lead wiring 75E and are drawn out to the side surfaces 10a and 10b of the coil component 1E. The spiral wiring 23E has a semi-elliptical arc shape when viewed from above and below. That is, the spiral wiring 23E is a curved wiring wound about half a circumference on the base insulating resin layer 30 (on the insulating layer). The number of turns of the spiral wiring 23E is not limited to about half a turn, and may be any number less than one turn.

The lead wire 75E of the first coil L1 has a shape in which one end is connected to the first columnar electrodes 71a and 71b located on the outside and extends from the first columnar electrodes 71a and 71b toward the center of the coil component 1E. The lead wiring 75E of the fourth coil L4 has a shape in which one end is connected to the fourth columnar electrodes 74a and 74b located on the outside and extends from the fourth columnar electrodes 74a and 74b toward the center of the coil component 1E. The spiral wirings 23E of the first and fourth coils L1 and L4 have both ends connected to the other ends of the lead wiring 75E, and have a curved shape that draws an arc from the other ends toward the edge side of the coil component 1E.

The lead wire 75E of the second coil L2 has a shape in which one end is connected to the second columnar electrodes 72a and 72b located inside and extends from the second columnar electrodes 72a and 72b to the edge side of the coil component 1E. The lead wire 75E of the third coil L3 has a shape in which one end is connected to the third columnar electrodes 73a and 73b located inside and extends from the third columnar electrodes 73a and 73b to the edge side of the coil component 1E. The spiral wirings 23E of the second and third coils L2 and L3 have both ends connected to the other ends of the lead wiring 75E, and have a curved shape that draws an arc from the other ends toward the center side of the coil component 1E.

Here, in the coil component 1E, inside the innermost circumference of the spiral wiring 23E for each of the coils L1 to L4 (the range surrounded by the curve of the spiral wiring 23E and the straight line connecting both ends of the spiral wiring 23E). Is the inner diameter part. At this time, in the coil component 1E, the inner diameter portions of any of the coils L1 to L4 do not overlap each other when viewed from the vertical direction.

On the other hand, in the coil component 1E, the lead wirings 75E of the first and second coils L1 and L2 are close to each other at the other ends, whereby the spiral wirings 23E of the first and second coils L1 and L2 are both ends thereof. Since they are close to each other and have a curved shape that draws an arc on the opposite side, they form one elliptical arc. The lead wires 75E of the third and fourth coils L3 and L4 are close to each other at the other ends, whereby the spiral wires 23E of the third and fourth coils L3 and L4 are close to each other at both ends and each other. Since it is a curved line that draws an arc on the opposite side, it forms one elliptical arc. That is, the spiral wiring 23E of the first and second coils L1 and L2 and the spiral wiring 23E of the third and fourth coils L3 and L4 each form an ellipse, thereby sharing the inner diameter portion of the ellipse. .. In the elliptical inner diameter portion, the magnetic flux generated by the first and second coils L1 and L2 and the magnetic flux generated by the third and fourth coils L3 and L4 are concentrated, so that the first coil L1 and the second coil L1 The magnetic coupling between the third coil L3 and the fourth coil L4 becomes stronger.

That is, in the coil component 1E, the first coil L1 and the second coil L2 form a pair, and the third coil L3 and the fourth coil L4 form a pair, as in the coil component 1 of the first embodiment. The coils L1 to L4 are configured to form two pairs. Further, the magnetic coupling between the paired first coil L1 and the second coil L2 is such that the magnetic coupling between the unpaired first coil L1 and the third and fourth coils L3 and L4 and the second coil L2 and the third coil. It is stronger than the magnetic coupling with the fourth coils L3 and L4. Further, the magnetic coupling between the third coil L3 and the fourth coil L4 that form a pair is the magnetic coupling between the third coil L3 and the first coil L1 and the second coil L1 and L2 that do not form a pair, and the fourth coil L4 and the first coil. It is stronger than the magnetic coupling with the second coils L1 and L2. Actually, regarding the configuration of the coil component 1E, when the calculation of the 3D magnetic field analysis result using the magnetic field analysis software Femtet was performed under the same conditions as the coil component 1D, the first coil L1 and the second coil L2 paired with each other were calculated. The absolute value of the coupling coefficient of the above was 1.5 times or more the absolute value of the coupling coefficient of the second coil L2 and the third coil L3 adjacent to each other on the base insulating resin layer 30. Further, the absolute value of the coupling coefficient between the second coil L2 and the fourth coil L4 having a large distance between the inner diameter portions was smaller than the absolute value of the coupling coefficient.

Therefore, in the coil component 1E, when one of the coils L1 to L4 is the first coil, the coil paired with the first coil is the second coil, and the coils other than the first coil and the second coil are the other coils. , The magnetic coupling between the first coil and the second coil is stronger than the magnetic coupling between the first coil and the other coils. Therefore, even in the coil component 1E, when used in the polyphase SW regulator, the ripple current of each coil L1 to L4 can be reduced by appropriately selecting the pulse signal input to each coil L1 to L4. Further, in the coil component 1E, since each coil L1 to L4 is composed of one layer of spiral wiring 23E, the height of the coil component 1E can be reduced. Further, unlike the coil component 1B of the third embodiment, it is not necessary to form a wiring layer other than the spiral wiring 23E, and the height can be further reduced. In the coil component 1E, all the spiral wirings 23E are laminated on the base insulating layer 30, and the insulating resin 35 can have a two-layer structure, so that the height can be further reduced. The outer surfaces of the first to fourth columnar electrodes 71a to 74a and 71b to 74b may be provided with external terminals containing metals such as Cu, Ag, Ni, Sn, and Au. In this case, the mounting quality is improved. Can be made to. Further, the outer surfaces of the first to fourth columnar electrodes 71a to 74a and 71b to 74b may be external terminals, and in this case, the configuration suitable for embedding the coil component 1E in the mounting substrate can be used.

(7th Embodiment)
14A is a perspective perspective view showing the coil component 1F according to the seventh embodiment, FIG. 14B is a sectional view showing the coil component 1F, and FIG. 14C is a perspective top view showing the coil component 1F. The coil component 1F has a different shape of each coil L1 to L4 from the coil component 1E of the sixth embodiment. This different configuration will be mainly described below. In the seventh embodiment, the same reference numerals as those of the first to sixth embodiments have the same configuration as those of the embodiment, and thus the description thereof will be omitted.

As shown in FIG. 14A, in the coil component 1F, the first to fourth coils L1 to L4 are each composed of one layer of spiral wiring 23F. Further, as shown in FIG. 14B, the first to fourth coils L1 to L4 are all provided on the base insulating resin layer 30 and covered with the first insulating resin layer 31. Further, as shown in FIG. 14C, the spiral wiring 23F has a semi-elliptical arc shape when viewed from above and below. That is, the spiral wiring 23F is a curved wiring wound about half a circumference on the base insulating resin layer 30 (on the insulating layer).

The spiral wiring 23F of the first coil L1 is connected to the first columnar electrodes 71a and 71b whose both ends are located on the outside, and has a curved shape that draws an arc from the first columnar electrodes 71a and 71b toward the center side of the coil component 1F. Is. The spiral wiring 23F of the fourth coil L4 is connected to the fourth columnar electrodes 74a and 74b whose both ends are located on the outside, and has a curved shape that draws an arc from the fourth columnar electrodes 74a and 74b toward the center side of the coil component 1F. Is.

The spiral wiring 23F of the second coil L2 is connected to the second columnar electrodes 72a and 72b whose both ends are located inside, and has a curved shape that draws an arc from the second columnar electrodes 72a and 72b toward the edge side of the coil component 1F. be. The spiral wiring 23F of the third coil L3 is connected to the third columnar electrodes 73a and 73b whose both ends are located inside, and has a curved shape that draws an arc from the third columnar electrodes 73a and 73b toward the edge side of the coil component 1F. be.

Here, in the coil component 1F, inside the innermost circumference of the spiral wiring 23F for each of the coils L1 to L4 (the range surrounded by the curve of the spiral wiring 23F and the straight line connecting both ends of the spiral wiring 23F). Is the inner diameter part. At this time, in the coil component 1F, the inner diameter portions of any of the coils L1 to L4 do not overlap each other when viewed from the vertical direction.

On the other hand, in the coil component 1F, the spiral wirings 23F of the first and second coils L1 and L2 are close to each other. That is, the magnetic flux generated in the spiral wiring 23F of the first coil L1 wraps around the spiral wiring 23F of the adjacent second coil L2, and the magnetic flux generated in the spiral wiring 23F of the second coil L2 is close to the first coil. It wraps around the spiral wiring 23F of L1. This also applies to the third and fourth coils L3 and L4 in which the spiral wirings 23F are close to each other. Therefore, the magnetic coupling between the first coil L1 and the second coil L1 and the magnetic coupling between the third coil L3 and the fourth coil L4 become stronger.

That is, in the coil component 1F, the first coil L1 and the second coil L2 form a pair, and the third coil L3 and the fourth coil L4 form a pair, as in the coil component 1 of the first embodiment. The coils L1 to L4 are configured to form two pairs. Further, the magnetic coupling between the paired first coil L1 and the second coil L2 is such that the magnetic coupling between the unpaired first coil L1 and the third and fourth coils L3 and L4 and the second coil L2 and the third coil. It is stronger than the magnetic coupling with the fourth coils L3 and L4. Further, the magnetic coupling between the third coil L3 and the fourth coil L4 that form a pair is the magnetic coupling between the third coil L3 and the first coil L1 and the second coil L1 and L2 that do not form a pair, and the fourth coil L4 and the first coil. It is stronger than the magnetic coupling with the second coils L1 and L2. Actually, regarding the configuration of the coil component 1F, when the calculation of the 3D magnetic field analysis result using the magnetic field analysis software Femtet was performed under the same conditions as the coil component 1D, the first coil L1 and the second coil L2 paired with each other were calculated. The absolute value of the coupling coefficient of the above was four times or more the absolute value of the coupling coefficient of the second coil L2 and the third coil L3 adjacent to each other on the base insulating resin layer 30. Further, the absolute value of the coupling coefficient between the second coil L2 and the fourth coil L4 having a large distance between the inner diameter portions was smaller than the absolute value of the coupling coefficient.

Therefore, in the coil component 1F, when one of the coils L1 to L4 is the first coil, the coil paired with the first coil is the second coil, and the coils other than the first coil and the second coil are the other coils. , The magnetic coupling between the first coil and the second coil is stronger than the magnetic coupling between the first coil and the other coils. Therefore, even in the coil component 1F, when used in a polyphase SW regulator, the ripple current of each coil L1 to L4 can be reduced by appropriately selecting the pulse signal input to each coil L1 to L4. Further, in the coil component 1F, since each coil L1 to L4 is composed of one layer of spiral wiring 23F, the height of the coil component 1F can be reduced. Further, unlike the coil component 1B, it is not necessary to form a wiring layer other than the spiral wiring 23F, and the height can be further reduced. In the coil component 1F, all the spiral wirings 23F are laminated on the base insulating layer 30, and the insulating resin 35 can have a two-layer structure, so that the height can be further reduced.

In the coil component 1F, when currents flow simultaneously from one end on the same side to the other end on the opposite side in the first and second coils L1 and L2, the magnetic fluxes of the first and second coils strengthen each other. This is the case where both ends on the same side of the first coil L1 and the second coil L2 are on the input side of the pulse signal, and the other ends on the opposite side are both on the output side of the pulse signal. It means that L1 and the second coil L2 are positively coupled. However, for example, if one coil of the first coil L1 and the second coil L2 has one end side as an input and the other end side as an output, and the other coil has one end side as an output and the other end side as an input, a pair can be obtained. The first coil L1 and the second coil L2 can be in a negatively coupled state. This also applies to the third and fourth coils L3 and L4.

Further, in the coil component 1F, the adjacent portions of the first and second coils L1 and L2 are interposed through an insulating resin layer having a magnetic permeability of 1, for example, and the distance between the spiral wirings 23F is, for example, 10 μm while ensuring the withstand voltage. It is possible to make it narrower. In this case, the magnetic resin does not exist between the adjacent portions, but if they are sufficiently close to each other, it is possible to secure the magnetic bond as in the above calculation result.

FIG. 14D is a perspective perspective view showing the coil component 1G according to the modified example of the seventh embodiment. The coil component 1G has a different arrangement of columnar electrodes from the coil component 1F. First, the end of each coil L1 to L4 on the first side surface 10a side of the prime field 10 is one end, and the end of each coil L1 to L4 on the second side surface 10b side is the other end. In the coil component 1G, the first and third columnar electrodes 71a and 73a connected to one end side of the first and third coils L1 and L3, and the other end side of the second and fourth coils L2 and L4 are connected. The second and fourth columnar electrodes 72b and 74b are exposed on the upper side of the prime field 10, respectively. Further, the first and third columnar electrodes 71b and 73b connected to the other end side of the first and third coils L1 and L3, and the second connected to the other end side of the second and fourth coils L2 and L4. 2. The fourth columnar electrodes 72a and 74a are exposed on the lower side of the prime field 10, respectively.

According to this configuration, for example, the coil component 1G is embedded in the mounting substrate, the pulse signal input line is arranged on the upper surface side of the prime field 10, and the pulse signal output line is arranged on the lower surface side of the prime field 10. Therefore, the pair of the first and second coils L1 and L2 and the third and fourth coils L3 and L4 can be more easily negatively coupled.

FIG. 14E is a perspective perspective view showing the coil component 1H according to the modified example of the seventh embodiment. The coil component 1H has a different arrangement of columnar electrodes from the coil component 1F. Specifically, in the coil component 1H, the first and third columnar electrodes 71a, 71b, 73a, 73b connected to the first and third coils L1 and L3 are exposed from the prime field 10 on the lower side, respectively. do. The second and fourth columnar electrodes 72a, 72b, 74a, 74b connected to the second and fourth coils L2 and L4 are exposed from the prime field 10 on the upper side, respectively.

According to this configuration, the adjacent 1st to 4th external terminals (1st to 4th columnar electrodes) of the coil component 1H are exposed on different surfaces, so that the coil component 1H has the same external size. The space between the terminals can be increased with respect to the coil component 1F, and a short circuit between the terminals can be less likely to occur when the wiring is connected to the mounting board.

(8th Embodiment)
In the second to seventh embodiments, the prime field in which the insulating layer is laminated and the wiring wound on the insulating layer, that is, the so-called laminated coil, are configured, but as in the first embodiment. , The configuration in which the strength of the magnetic coupling is adjusted between the paired coil and the unpaired coil is not limited to this.

FIG. 15 is a schematic view showing the coil component 1J according to the eighth embodiment. The coil component 1J is different from the coil component 1A of the second embodiment in the configuration of the prime field 10 and the configurations of the coils L1 to L4. This different configuration will be mainly described below. In the eighth embodiment, the same reference numerals as those of the first to seventh embodiments have the same configuration as that of the embodiment, and thus the description thereof will be omitted.

As shown in FIG. 15, in the coil component 1J, the prime field 10 is composed of the first core 40A, the second core 40B, and the sealing resin 35A, and the first to fourth coils L1 to L4 are the first, respectively. , It is composed of windings wound around the second cores 40A and 40B.

The first and second cores 40A and 40B each have a substantially quadrangular frame shape, and are made of a magnetic material such as ferrite or iron. External terminals 11a to 14a and 11b to 14b are formed on a set of opposite sides of the first and second cores 40A and 40B. The sealing resin 35A is a member for sealing both the first and second cores 40A and 40B in one prime field 10, and is made of an insulating material such as an epoxy resin. Here, the first core 40A and the second core 40B are arranged at intervals.

The first to fourth coils L1 to L4 are, for example, an insulatingly coated copper wire, which is wound around one side of the first and second cores 40A and 40B, and both ends thereof are first to fourth external terminals. It is connected to 11a to 14a and 11b to 14b. Here, the first and second coils L1 and L2 are one of a set of opposite sides of the first core 40A in which the first and second external terminals 11a, 11b, 12a and 12b are not formed. On the other hand, they are wound in the same direction. Further, the third and fourth coils L3 and L4 are one of the sets of opposite sides of the second core 40B in which the third and fourth external terminals 13a, 13b, 14a and 14b are not formed, and the other. They are wound in the same direction. That is, in the coil component 1J, the first coil L1 and the second coil L2 are wound around the same first core 40A, and the third coil L3 and the fourth coil L4 are wound around the same second core 40B. ..

With the above configuration, in the coil component 1J, the magnetic coupling between the first coil L1 and the second coil L2 and the magnetic coupling between the third coil L3 and the fourth coil L4 become stronger. On the other hand, since the first core 40A and the second core 40B are arranged at intervals, the magnetic coupling between the first coil L1 and the third and fourth coils L3 and L4 is weak, and the second coil L2 and the second coil L2 3. The magnetic coupling with the fourth coils L3 and L4 becomes weak.

Therefore, in the coil component 1J, the first coil L1 and the second coil L2 form a pair, and the third coil L3 and the fourth coil L4 form a pair, as in the coil component 1 of the first embodiment. The four coils L1 to L4 are configured to form two pairs. Further, the magnetic coupling between the paired first coil L1 and the second coil L2 is such that the magnetic coupling between the unpaired first coil L1 and the third and fourth coils L3 and L4 and the second coil L2 and the third coil. It is stronger than the magnetic coupling with the fourth coils L3 and L4. Further, the magnetic coupling between the third coil L3 and the fourth coil L4 that form a pair is the magnetic coupling between the third coil L3 and the first coil L1 and the second coil L1 and L2 that do not form a pair, and the fourth coil L4 and the first coil. It is stronger than the magnetic coupling with the second coils L1 and L2.

Therefore, in the coil component 1J, when one of the coils L1 to L4 is the first coil, the coil paired with the first coil is the second coil, and the coils other than the first coil and the second coil are the other coils. , The magnetic coupling between the first coil and the second coil is stronger than the magnetic coupling between the first coil and the other coils. Therefore, even in the coil component 1J, when used in the polyphase SW regulator, the ripple current of each coil L1 to L4 can be reduced by appropriately selecting the pulse signal input to each coil L1 to L4.

Further, in the coil component 1J, one end of the first coil L1 and one end of the second coil L2 are drawn out to the same one side with respect to the first coil L1 and the second coil L2, and the first coil L1. The other end and the other end of the second coil L2 are drawn out to the same other side with respect to the first coil L1 and the second coil L2. Further, since the first coil L1 and the second coil L2 are wound in the same direction, they are negatively coupled when one end is from the input side of the pulse signal to the other end to the output side of the pulse signal. That is, the first coil L1 and the second coil L2 are wound so that the magnetic fluxes cancel each other out in the core 40A when a current flows from one end to the other end. This is the same for the third coil L3 and the fourth coil L4.

Therefore, in the coil component 1J, when the pulse signal is input so that all the paired coils are negatively coupled, the input side and the output side of the coils L1 to L4 can be aligned on the same side. This makes it easier to route the wiring on the board on which the coil component 1J is mounted.

(9th Embodiment)
FIG. 12 is a simplified configuration diagram showing an embodiment of the switching regulator of the present invention. As shown in FIG. 12, the switching regulator 5 (hereinafter referred to as “regulator 5”) is a step-down type switching regulator, and the input voltage Vin is stepped down to a predetermined output voltage and supplied to the load 7. The regulator 5 includes the coil component 1, the switch portions S1 to S (2N) connected to each of the ends of the coils L1 to L (2N) of the coil component 1, and the coils L1 to L1 to the coil component 1. It has a capacitor 6 (as an example of a smoothing circuit) connected to the other end side of L (2N). The regulator 5 is a multi-phase SW regulator, and a pair of switch portions S1 to S (2N) and coils L1 to L (2N) is connected in parallel between the input voltage Vin and the capacitor 6.

The coil component 1 has the same configuration as the coil component 1 of the first embodiment (FIG. 1). Since the same reference numerals as those of the first embodiment have the same configurations as those of the first embodiment, the description thereof will be omitted.

Each switch unit S1 to S (2N) connects either the input voltage Vin or the ground voltage to the coils L1 to L (2N) connected to itself (corresponding to itself) (synchronous rectification method). .. That is, a pulse signal which is a rectangular wave having two values of an input voltage Vin and a ground voltage is input to each coil L1 to L (2N). Here, each switch unit S1 to S (2N) state when the input voltage Vin is connected to the coils L1 to L (2N) corresponding to itself is turned on, and the corresponding coils L1 to L (2N) are grounded. The S1 to S (2N) states of each switch unit when the voltage is connected are set to the off state. Switching between the on state and the off state is performed by driving signals P1 to P (not shown) input to each switch unit S1 to S (2N) from a PWM (Pulse Width Modulation) generator (not shown) provided in the regulator 5. It is controlled by 2N).

Specifically, a certain oscillation frequency is set in the regulator 5, and the PWM generator shifts each switch unit S1 to S (2N) to the on state by the drive signals P1 to P (2N) at the oscillation frequency (turn-on). ). That is, the interval between turn-ons is the reciprocal of the oscillation frequency. This means that a square wave pulse signal having a constant and same period (reciprocal of the oscillation frequency) is input to each of the coils L1 to L (2N).

Further, the regulator 5 includes a detection circuit (not shown) that detects the output voltage of the coils L1 to L (2N) and the current flowing through the coils L1 to L (2N), and the detection circuit detects a voltage or current above a certain level. When detected, the PWM generator shifts each switch unit S1 to S (2N) to the off state by the drive signals P1 to P (2N) (turn-off). Here, in a state where the power consumption of the load 7 does not fluctuate (steady state), the interval from turn-on to turn-off is constant. That is, in the steady state, the 2N pulse signals input to each coil L1 to L (2N) have a constant and same duty ratio (interval between turn-on and turn-off / oscillation frequency) within a constant and same cycle. It has the reciprocal).

Further, the regulator 5 is a multi-phase SW regulator, and when the reciprocal of the oscillation frequency is represented by a phase of 360 °, the drive signals P1 to P (2N) are signals whose turn-on intervals are shifted by 360 ° / (2N). That is, it is a set of signals having a phase difference of 360 ° / (2N). At this time, the pulse signals input from each coil L1 to L (2N) are also a set of signals having a phase difference of 360 ° / (2N). As a result, the peaks of the voltages output from each coil L1 to L (2N) are evenly deviated, so that the difference between the minimum and maximum values of the combined voltage of the output voltage, that is, the ripple input to the capacitor 6. The voltage can be reduced.

When a pulse signal having a phase difference of 360 ° / (2N) is input from one end of each coil L1 to L (2N), the inductance of each coil L1 to L (2N) causes the pulse signal. The pulse signal of the square wave is converted into the pulse signal of the triangular wave, and the triangular wave is output from the other end of each coil L1 to L (2N).

The output triangular wave is smoothed by the capacitor 6 connected to the other end side of the coils L1 to L (2N), and is supplied to the load 7 in the subsequent stage. At this time, the voltage (output voltage) supplied to the load 7 is the product of the input voltage Vin and the duty ratio. As described above, in the regulator 5, the input voltage Vin is stepped down to a predetermined output voltage and supplied to the load 7 by appropriately setting the constant duty ratio.

Here, the regulator 5 has a coil component 1. Therefore, the ripple current of each coil L1 to L (2N) can be reduced by appropriately selecting the pulse signal to be input to each coil L1 to L (2N). Specifically, in the regulator 5, M is an integer of 1 or more and N or less, and the signal P (2M-1) is (360 ° / (2N)) × (M-1) phase difference with respect to the signal P1. As the signal P (2M), a signal having a phase difference of (360 ° / (2N)) × (M-1) + 180 ° with respect to the signal P1 is selected. At this time, a pulse signal having a phase difference of 180 ° is input to the coils L (2M-1) and the coils L (2M) forming all the pairs of the coil component 1, and the coils L1 to L (2N) have a phase difference of 180 °. The ripple current can be reduced.

Therefore, in the regulator 5, by reducing the ripple current, the loss due to heat generation in each coil L1 to L (2N) is reduced, and the efficiency is improved. Further, in the regulator 5, by reducing the ripple current, the inductance value required for each coil L1 to L (2N) and the capacitance value required for the capacitor 6 can be reduced, the transient response speed is improved, and the circuit size is reduced. Can be achieved. That is, the regulator 5 can be improved in performance and miniaturized.

In the above, the regulator 5 is a PWM method, but a PFM (Pulse Frequency Modulation) method may be used. Even in the PFM method, in the steady state, the 2N pulse signals input to each coil L1 to L (2N) have a constant and the same duty ratio in a constant and the same period, and are 360 ° / (2N). ) Is a set of signals with a phase difference. Therefore, even in this case, the regulator 5 can be improved in performance and miniaturized by appropriately selecting 2N pulse signals.

Further, in the above, the switch units S1 to S (2N) are of the synchronous rectification method, but the present invention is not limited to this, and for example, each switch unit S1 to S (2N) has one switching element and a diode (diode). It may be a rectification method).

Further, in the above, the regulator 5 is a step-down type, but even if it is a step-up type or a step-up / down type multi-phase SW regulator, by having the coil component 1, the ripple current of each coil L1 to L (2N) can be reduced. By reducing the amount, it is possible to improve the performance and reduce the size.

The present invention is not limited to the above-described embodiment, and the design can be changed without departing from the gist of the present invention. For example, the feature points of the first to ninth embodiments may be combined in various ways.

In the second to eighth embodiments, the coil component has four coils, but it may have (2N) coils (N is an integer of 2 or more), and even if N> 2. good. Further, in the second embodiment, each coil has two layers of spiral wiring, but may have three or more layers of spiral wiring.

In the second embodiment, the coil has a structure in which a plurality of spiral wirings having one or more turns are laminated, but a three-dimensional spiral structure in which a plurality of spiral wirings having less than one turn are laminated may be used. ..

Further, in the above embodiment, the effect when the paired coils are negatively coupled has been mainly described, but when the coupling coefficient of the paired coils is positive, that is, when a current flows through the paired coils at the same time. In addition, the paired coils may be magnetically coupled so that the magnetic fluxes of each other are strengthened. This makes it possible to reduce the input ripple current to the paired coils. In order to make the coupling coefficient of the paired coils positive, for example, in the coil component 1, the winding direction of one of the paired coil sets, for example, the coils L1 and L2 may be reversed. Then, the input / output of the pulse signal may be reversed for one of the coils L1 and L2. Further, for example, in the coil component 1A, the paired coils L1 and L2 may be wound in the same direction.

Further, in the coil component 1A, all the coils (spiral wiring) may be wound in the same direction. At this time, the shape, arrangement, manufacturing conditions, etc. of each coil can be easily aligned, the deviation of the electrical characteristics can be reduced, and the manufacturing can be facilitated. In addition, the paired coils can be easily positively coupled.

Further, in the coil component 1A, a plurality of coils (for example, coils L1 and L4) are laminated on the same insulating layer (for example, the base insulating layer 30), and the plurality of coils are wound in different directions. Not limited to this, the plurality of coils may be wound in the same direction. In this case, since the plurality of coils laminated on the same insulating layer are wound in the same direction, they are adjacent to each other on the same insulating layer having a relatively large magnetic coupling among the pair of unpaired coils. The set of coils can be easily negatively coupled, and the ripple current of each coil can be further suppressed.

1, 1A to 1H, 1J Coil parts 5 Switching regulator 6 Capacitor (smoothing circuit)
7 Load 10 Element 10a 1st side surface 10b 2nd side surface 11a to 14a, 11b to 14b 1st to 4th external terminals 21, 22 1st and 2nd spiral wiring 21a, 22a Inner peripheral end 21b, 22b Outer peripheral end 23D ~ 23F Spiral wiring 23a One end 23b Other end 25 Via wiring 30 Base insulating resin layer 31-34 1st to 4th insulating resin layer 35 Insulating resin 35A Encapsulating resin 40 Magnetic resin 40A, 40B 1st, 2nd core 41a-41c 1st 1st to 3rd magnetic resin body 42 Magnetic resin layer 71 to 74 1st to 4th columnar electrodes 75,75E Drawer wiring L1 to L (2N) 1st to 1st (2N) coils S1 to S (2N) 1st to 1st (2N) Switch section

Claims (14)

It is a coil component used for multi-phase SW regulators.
It has 2N coils (N is an integer of 2 or more) and has
The 2N coils are configured to form N pairs.
When a coil other than the first coil and the second coil forming one of the N pairs is used as the other coil, the magnetic coupling between the first coil and the second coil is the first coil and the other coil. Stronger than the magnetic coupling with the coil of
In each of the N pairs of coils
One end of the pair of coils and one end of the other coil of the pair are drawn out to the same one side with respect to the one coil and the other coil, and the other end of the one coil and the other end. The other end of the coil is drawn out to the same other side with respect to the one coil and the other coil.
A coil component in which one coil and the other coil are wound so that magnetic fluxes cancel each other when a current flows from one end to the other end . The coil component according to claim 1, wherein the magnetic coupling between the first coil and the second coil is stronger than the magnetic coupling between the second coil and the other coil. The coil component according to claim 2, wherein the magnetic coupling between the paired coils is stronger than any of the magnetic couplings between the unpaired coils. Further provided with a prime field in which a plurality of insulating layers are laminated in the first direction,
Each of the 2N coils is arranged inside the prime field and is composed of spiral wiring wound on the insulating layer.
For each of the 2N coils, it is assumed that the inner side of the innermost circumference of the spiral wiring is the inner diameter portion of the coil.
The coil according to any one of claims 1 to 3 , wherein at least a part of the inner diameter portion of the first coil and at least a part of the inner diameter portion of the second coil overlap each other when viewed from the first direction. parts. The coil component according to claim 4 , wherein the inner diameter portion of the first coil and the inner diameter portion of the other coil do not overlap each other when viewed from the first direction. The coil component according to claim 4 or 5 , wherein the first coil and the second coil are wound in different directions. A plurality of the coils are laminated on the same insulating layer, and the coils are laminated.
The coil component according to any one of claims 4 to 6 , wherein the plurality of the coils are wound in the same direction. The coil component according to any one of claims 4 to 7 , wherein the 2N coils are all wound in the same direction. The first coil and the second coil are each composed of a plurality of the spiral wirings wound on the plurality of the insulating layers.
4 . The coil parts described in one. The spiral wiring of a plurality of the coils is wound around the same insulating layer.
The coil component according to any one of claims 4 to 9 , wherein the shortest distance between the spiral wirings is longer than the wiring interval in the spiral wirings. One end of the first coil and one end of the second coil are drawn out to the same one side with respect to the first coil and the second coil, and the other end of the first coil and the second coil. The other end of the coil is drawn out to the same other side of the first coil and the second coil.
One of claims 1 to 10 , wherein the first coil and the second coil are wound so that magnetic fluxes cancel each other when a current flows from one end to the other end. Coil parts listed in 1. The coil component according to claim 11 , wherein the number of turns, the coil wiring length, and the coil cross-sectional area of each of the first coil and the second coil are the same. The coil component according to claim 11 or 12 , wherein the first external terminal connected to the one end of the first coil and the second external terminal connected to the one end of the second coil are adjacent to each other. It has 2N coils (N is an integer of 2 or more) and has
The 2N coils are configured to form N pairs.
When a coil other than the first coil and the second coil forming one of the N pairs is used as the other coil, the magnetic coupling between the first coil and the second coil is the first coil and the other coil. Stronger than the magnetic coupling with the coil of
Further provided with a prime field in which a plurality of insulating layers are laminated in the first direction,
The 2N coils are arranged inside the prime field.
Each of the 2N coils is composed of curved spiral wiring wound less than one turn.
The 2N coils are provided on the same insulating layer.
Assuming that the inner diameter portion of each of the 2N coils is the inner diameter portion of the spiral wiring inside the innermost circumference, the inner diameter portions of any of the coils do not overlap each other when viewed from the first direction. , Coil parts.

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