JP7081697B2 - Multilayer inductor component - Google Patents

Description

The present invention relates to a laminated inductor component formed by laminating an insulator layer and a coil conductor layer.

In recent years, as the carrier frequency of communication devices such as mobile phones has increased, a large number of coiled inductors corresponding to high frequencies in the GHz band have been used in the signal transmitting section and signal receiving section of these devices. It has become.

As one type of such an inductor, it has an element body which is an insulator and a plurality of coil conductor layers extending along a plane in the element body, and each coil conductor layer is passed through a via formed in the element body. A laminated inductor component in which a coil is formed in a prime field by electrically connecting has been put into practical use. The coil conductor layer is formed, for example, by firing a conductive paste containing a metal in a resin, sputtering, plating, or the like.

In the multilayer inductor component as described above, it is necessary to secure a high Q value (quality factor) in order to improve the performance of the communication device operating at a high frequency. In order to improve the Q value, it is required to reduce the resistance of the coil and increase the efficiency of the inductance that can be acquired with respect to the outer shape of the prime field (inductance acquisition efficiency).

Here, since the high-frequency current flowing through the coil conductor layer flows near the surface of the coil conductor layer due to the skin effect, it is necessary to increase the surface surface of the coil conductor layer in order to reduce the resistance of the coil to the high-frequency current. It is valid.

In Patent Document 1, the surface area of the coil conductor layer is increased by the pores formed by sintering the metal around the resin before the resin is gasified and scattered in the conductive paste during firing. Disclosed are laminated inductor components designed to reduce the resistance of the coil.

Japanese Unexamined Patent Publication No. 2014-45081

FIG. 11 shows a laminated inductor component disclosed in Patent Document 1. In the inductor component 1, the surface area of the coil conductor layer 2 is increased by the holes 3 formed in the coil conductor layer 2 (coil conductor) to reduce the resistance of the coil.

On the other hand, since the gasification temperature of the resin in the conductive paste is usually lower than the sintering completion temperature of the metal powder which is the main component of the conductive paste, the pores 3 are included in the metal portion of the coil conductor layer 2 after firing. It is difficult to form a shape.

Further, since the material of the element body 4 covering the coil conductor layer 2, for example, glass powder, is sintered faster than the metal powder, the gas generated in the conductive paste is less likely to scatter to the outside of the element body 4. It tends to stay near the outer peripheral edge of the coil conductor layer 2, and pores 3 tend to be formed in the region.

In the laminated inductor component 1 thus formed, the outer peripheral edge is actually formed in FIGS. 11 (a) and 11 (b) due to the holes 3 formed in the vicinity of the outer peripheral edge of the coil conductor layer 2. The shape is not as smooth as shown in the above, and severe unevenness occurs. In the coil conductor layer 2 having such a shape, the smooth flow of the current is hindered, the loss due to the partial concentration of the current, the generation of the eddy current due to the disturbance in the magnetic flux direction, etc. increases, and the inductance acquisition efficiency decreases. .. Further, the holes 3 formed in the vicinity of the outer peripheral edge of the coil conductor layer 2 may reduce the strength of the coil conductor layer 2 and may cause disconnection of the coil or high resistance. That is, as in Patent Document 1, when trying to reduce the resistance of the coil by the pores 3 of the coil conductor layer 2, various problems may occur.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a laminated inductor component capable of reducing the resistance of a coil regardless of holes.

The laminated inductor component that solves the above problems includes an element body that is an insulator and a coil in which a plurality of coil conductor layers extending along a plane in the element body are electrically connected, and the coil conductor is provided. The layer includes a metal portion and a glass portion, and the element body includes glass, and the glass of the element body within 10 μm around the coil conductor layer is the peripheral glass, and the element body further outside the peripheral glass. When the glass is an outer glass, the peripheral glass is a filler element which is one of Bi, Li, Na, K, Mg, Ca, Sr, Ba, Co, Zn, B, Pb, Al, Zr, P, and V. The peripheral glass has a higher concentration of the filler element than the outer glass.

According to the laminated inductor component of the present invention, the resistance of the coil can be reduced regardless of the holes.

The perspective view which shows the laminated inductor component. An exploded perspective view showing an outline of each part of a laminated inductor component. (A) to (d) are explanatory views showing a firing process of a coil conductor. (A) to (d) are explanatory views showing a firing process of a coil conductor. (A) to (d) are schematic views showing a firing process of a coil conductor. The schematic diagram which shows the coil conductor in a firing process. Explanatory drawing which shows the calculation method of the diameter of the crystallite of a coil conductor. The schematic diagram which shows the coil conductor in a firing process. Schematic cross-sectional view showing the laminated body after firing. The schematic plan view which shows the laminated body after firing. (A) and (b) are sectional views showing a conventional laminated coil component.

Hereinafter, embodiments, which are one aspect of the present invention, will be described with reference to the drawings.
The laminated inductor component 10 shown in FIG. 1 is arranged along the outer surface of the prime field 11 which is an insulator, the coil 12 formed in the prime field 11, and the prime field 11, and each of them is the first end of the coil 12. , A first external electrode 13x and a second external electrode 13y electrically connected to the second end.

The prime field 11 is formed by laminating a plurality of insulator layers, and the coil 12 has a plurality of coil conductor layers extending along a plane corresponding to the main surface of the insulator layer in the prime field 11 with vias 14. It is formed by being electrically connected.

Further, the outer surface of the prime field 11 is a mounting surface 11a on which both the first external electrode 13x and the second external electrode 13y are arranged, a first end surface 11b on which only the first external electrode 13x is arranged, and a second external electrode. The mounting surface 11a, the first end surface 11b, and the second end surface 11c include the second end surface 11c on which only 13y is arranged, and are orthogonal to the main surface of the insulator layer. That is, as shown in FIG. 1, in the laminated inductor component 10, the mounting surface 11a, the laminating direction of the insulator layer, and the winding axis of the coil 12 are parallel to each other.

FIG. 2 shows an outline of each part of the laminated inductor component 10. The insulator layers 15a, 15b, 16a to 16c, 18 constituting the prime field 11, the coil conductor layers 12a to 12c constituting the coil 12, the first external electrode 13x, and the external electrode layers 13a to 13e constituting the second external electrode 13y. Are laminated, for example, from the lower side of the paper surface in FIG. 2 toward the upper side of the paper surface. In FIG. 1, for example, the prime fields 11 are sequentially laminated from the front side to the back side. The stacking direction may be opposite in FIGS. 1 and 2.

The following is an example of a method for manufacturing the laminated inductor component 10 with reference to FIG. 2. First, an insulating paste containing glass powder is repeatedly applied on a substrate (not shown) by screen printing to form a marker insulating paste layer 18 and an outer layer insulating paste layer 15a in this order. Next, a photosensitive conductive paste containing metal powder and glass powder is applied onto the insulating paste layer 15a for the outer layer, and patterned by a photolithograph step to form a pair of external electrode patterns 13a.

One external electrode pattern 13a extends from a position corresponding to the mounting surface 11a of the outer layer insulating paste layer 15a to a position corresponding to the first end surface 11b, and the other external electrode pattern 13a is formed on the mounting surface 11a of the outer layer insulating paste layer 15a. From the corresponding position to the position corresponding to the second end surface 11c side, each is formed in an L shape.

Next, a photosensitive insulating paste containing glass powder is applied onto the outer layer insulating paste layer 15a on which the external electrode pattern 13a is formed, and patterned by a photolithograph step to form an opening 17 on the external electrode pattern 13a. The insulating paste layer 16a is formed.

Next, the above conductive paste is applied on the insulating paste layer 16a and on the opening 17, and the pattern is patterned by a photolithograph step so as to make about one round along the main surface of the pair of external electrode patterns 13b and the insulating paste layer 16a. A coil conductor pattern 12a is formed so as to extend to. The coil conductor pattern 12a is integrally formed so as to be electrically connected to one of the external electrode patterns 13b. The external electrode pattern 13b is laminated on the external electrode pattern 13a via the opening 17, and is electrically connected to each other.

Next, the above-mentioned photosensitive insulating paste is applied onto the insulating paste layer 16a on which the external electrode pattern 13b and the coil conductor pattern 12a are formed, and the above-mentioned photosensitive insulating paste is patterned by a photolithography step to form an opening 17 similar to the insulating paste layer 16a. And the insulating paste layer 16b on which the via 14 is formed is formed. The via 14 is formed on the end portion of the coil conductor pattern 12a on the side not connected to the external electrode pattern 13b.

Next, the above conductive paste is applied on the insulating paste layer 16b, in the opening 17 and in the via 14, and patterned by a photolithography step, and about along the main surface of the pair of external electrode patterns 13c and the insulating paste layer 16b. A coil conductor pattern 12b that extends so as to make one round is formed. One end of the coil conductor pattern 12b is electrically connected to the underlying coil conductor pattern 12a via a conductive paste applied in the via 14. Further, the external electrode pattern 13c is laminated on the external electrode pattern 13b via the opening 17, and is electrically connected to each other.

By repeating the above steps in an appropriate combination, the coil conductor patterns 12a to 12c connected via the insulating paste layers 16a to 16d and the opening 17 are laminated. Further, the coil conductor pattern 12c on the uppermost layer is integrally formed so as to be electrically connected to the other external electrode pattern 13d on the end side opposite to the via 14.

Then, the insulating paste is applied onto the insulating paste layer 16d on which the external electrode pattern 13e is formed, and the insulating paste layer 15b for the outer layer and the marker insulating paste layer 18 are formed in this order to generate a laminated body.

A plurality of laminated inductor components 10 shown in FIG. 2 may be formed at the same time. In this case, a mother laminate in which a plurality of external electrode patterns 13a to 13e and coil conductor patterns 12a to 12c are arranged in a matrix may be formed, and the mother laminate may be cut into individual laminates by dicing. At this time, as shown in FIG. 1, the external electrode patterns 13a to 13e are exposed from the surfaces corresponding to the mounting surface 11a, the first end surface 11b, and the second end surface 11c of the laminated body. Further, in this case, the external electrode patterns 13a to 13e and the opening 17 may be formed in a T-shape or a cross shape instead of an L-shape, and may be formed in an L-shape by the above dicing.

Next, the laminate is fired under predetermined conditions, the insulating paste layer, the coil conductor pattern, and the external electrode pattern are sintered to form the insulator layer, the coil conductor layer, and the external electrode layer, and then barrel processing is performed. The element body 11, the coil 12, and the external electrodes 13x and 13y shown in FIG. 1 are formed. After that, Ni plating and Sn plating having a thickness of 2 μm to 10 μm are applied to the external electrodes 13x and 13y in this order to complete the laminated inductor component 10.

In the above, the insulating paste used as the material of the insulating paste layers 15a and 15b for the outer layer, the insulating paste layers 16a to 16d, and the marker insulating paste layer 18 is, for example, a glass paste containing glass powder in a varnish. The insulating paste used as the material for the outer layer insulating paste layers 15a and 15b and the marker insulating paste layer 18 may be photosensitive or non-photosensitive. Further, the insulating paste used as the material of the marker insulating paste layer 18 may contain a pigment, whereby each surface of the laminated inductor component 10 can be identified.

The photosensitive conductive paste forming the coil conductor patterns 12a to 12c and the external electrode patterns 13a to 13e is, for example, a paste in which metal powder such as Ag, Cu, Au or the like and glass powder are contained in the varnish. Bi, Li, Na, K, Mg, Ca, Sr, Ba, Co, Zn, B, Pb, Al, Zr, P, V and the like are added to the glass powder contained in the insulating paste and the conductive paste. May be good.

Next, the configurations of the coil conductor layers 12a to 12c in which the conductive paste containing such metal powder and glass powder is sintered in the firing step will be described.
3 (a) to 3 (d) show a cross section of the coils of the coil conductor layers 12a to 12c sintered at each firing temperature t1 to t3 and firing times T1 and T2 orthogonal to the stretching direction of the coil conductor layers 12a to 12c. (Cross section).

The firing temperatures t1 to t3 are t1 <t2 <t3, and the firing times T1 and T2 are T1 <T2. That is, the degree of sintering progress of the coil conductor layers 12a to 12c when the firing step is completed is higher in FIG. 3 (b) than in FIG. 3 (a), and in FIG. 3 (c) from FIG. 3 (b). ) Is more advanced, and FIG. 3 (d) is more advanced than FIG. 3 (b).

As shown in FIGS. 3A to 3D, the coil conductor layers 12a to 12c include a metal portion M in which the metal powder contained in the conductive paste is sintered and a glass portion GLA in which the glass powder is sintered. Further, the glass portion GLA includes an encapsulated glass GLAi contained in the metal portion M and an exposed glass GLAo exposed from the metal portion M.

Further, the prime field 11 includes a peripheral glass GLB as the glass of the prime field 11 within 10 μm around the coil conductor layers 12a to 12c. In FIGS. 3 (a) and 3 (b) where sintering has not progressed relatively, the glass portion GLA contains not only the contained glass GLAi but also the exposed glass GLAo, while the sintering has progressed in FIG. 3 (c). ), (D), it can be seen that the glass portion GLA does not include the exposed glass GLAo but contains only the contained glass GLAi. Further, it can be seen that the outer peripheral edge of the metal portion M is smoothed in proportion to the progress of sintering.

The details of the sintering process of the coil conductor layers 12a to 12c will be described with reference to the schematic diagram shown in FIG. As shown in FIG. 5A, the coil conductor patterns 12a to 12c before firing are photocured photosensitive conductive pastes in a state where the metal powder M and the glass powder GLA are dispersed in the varnish 19 as a binder. be.

When the firing is started in this state, as shown in FIG. 5B, the varnish 19 is burned and scattered, the metal powder M is sintered to become the metal portion M, and local shrinkage (necking) occurs. However, the interface between the adjacent metal portions M increases. At this time, the glass powder GLA is also sintered to form the glass portion GLA, but the glass portion GLA having a relatively low softening point softens and begins to flow at the interface of the metal portion M.

Next, as shown in FIG. 5 (c), the softened glass portion GLA flowing at the interface of the metal portion M further promotes the sintering of the metal portion M, and the particle size of the metal portion M becomes larger. Further, at this time, as the glass portion GLA, the encapsulated glass GLAi encapsulated in the metal portion M and sintered because the softening point is relatively high and the amount of flow is small, the softening point is relatively low and the metal portion M flows. Exposed glass GLAo sintered on the outer peripheral edge of is formed. Among the glass portions GLA, the one that softens and flows more than the exposed glass GLAo and is extruded around the metal portion M and sintered becomes the peripheral glass GLB of the prime field 11. Therefore, at this stage, the coil conductor layers 12a to 12c including the metal portion M and the glass portion GLA shown in FIGS. 3 (a) and 3 (b), the glass portion GLA containing the contained glass GLAi and the exposed glass GLAo, are formed. It is formed. At this time, since the coil conductor layers 12a to 12c are formed in a state of being partially surrounded by the softened peripheral glass GLB, the outside of the coil conductor layers 12a to 12c is composed of the metal portion M of the coil conductor layers 12a to 12c and the exposed glass GLAo. Peripheral smoothing is promoted.

Then, as shown in FIG. 5D, as the firing further progresses, the particle size of the metal portion M becomes larger, and the exposed glass GLAo is extruded around the metal portion M to become the peripheral glass GLB. As a result, at this stage, the coil conductor layers 12a to 12c including the metal portion M and the glass portion GLA and the glass portion GLA containing only the contained glass GLAi are formed, as shown in FIGS. 3 (c) and 3 (d). .. At this time, since the coil conductor layers 12a to 12c are formed in a state where the exposed glass GLAo is also extruded around the metal portion M, the outer peripheral edge of the metal portion M of the coil conductor layers 12a to 12c is smoothed.

As described above, the ratio of the contained glass GLAi in the glass portion GLA can be controlled by the amount of extruded (peripheral glass GLB) of the exposed glass GLAo, that is, the degree of progress of sintering.

4 (a) to 4 (d) show the coils sintered at each firing temperature t1 to t3 and each firing time T1 and T2 when Bi is added to the glass powder of the conductive paste forming the coil conductor layers 12a to 12c. The configurations of the conductor layers 12a to 12c are shown. By adding Bi, the temperature at which the glass portion sintered with glass powder softens (softening point) becomes lower than the softening point of the glass portion sintered with glass powder without Bi added.

As a result, even when compared at the same firing temperature and firing time as in FIG. 3, sintering progressed more than in the coil conductor layers 12a to 12c in FIG. 3, and the proportion of the contained glass GLAi in the glass portion GLA was large, and the coil. It can be seen that the smoothing of the outer peripheral edges of the conductor layers 12a to 12c is promoted. As described above, the ratio of the contained glass in the glass portion GLA can be adjusted by the presence or absence of Bi added to the glass powder. Further, the degree of decrease in the softening point of the glass portion sintered with the glass powder to which Bi is added is substantially proportional to the amount of Bi added. Therefore, the ratio of the contained glass can also be adjusted by the amount of Bi added to the glass powder.

As can be seen from the above description, among the glass powders contained in the coil conductor patterns 12a to 12c, those that become exposed glass GLAo or peripheral glass GLB instead of the contained glass GLAi have a relatively low softening point. It has high liquidity. Therefore, in the coil conductor layers 12a to 12c, the softening point of the exposed glass GLAo and the softening point of the peripheral glass GLB are equal to or lower than the softening point of the contained glass GLAi. The softening point of the peripheral glass GLB is equal to or lower than the softening point of the exposed glass GLAo. That is, the softening point is peripheral glass GLB ≧ exposed glass GLAo ≧ inclusion glass GLAi. When the glass of the element 11 outside the peripheral glass such as the central portion and the outer edge of the element 11 is the outer glass, the softening point of the peripheral glass GLB is preferably lower than the softening point of the outer glass. In this case, since the coil conductor layers 12a to 12c are formed in a state of being surrounded by the peripheral glass GLB which is relatively easy to soften, smoothing of the outer periphery of the coil conductor layers 12a to 12c is promoted and relatively softened. By having the outer glass that is difficult to make, the strength and shape stability of the prime field 11 are improved.

Further, the filler element added to the glass powder in order to lower the softening point of the glass portion is not limited to Bi, but Bi, Li, Na, K, Mg, Ca, Sr, Ba, Co, Zn, B, Pb, Al. , Zr, P, V. That is, it is preferable that the peripheral glass GLB contains one or more kinds of the filler elements, and at this time, the peripheral glass GLB has a higher concentration of the filler elements (total concentration of the filler elements) than the outer glass. Is preferable. Further, from the viewpoint of the softening point in the sintering process, when the glass powder contained in the conductor paste forming the coil conductor patterns 12a to 12c contains one or more of the above filler elements, the concentration of the filler elements is the peripheral glass. GLB ≧ exposed glass GLAo ≧ inclusion glass GLAi.

As shown in FIG. 6, when the softening point is lowered in the region exceeding 10 μm around the coil conductor layers 12a to 12c, that is, the outer glass, the excessive flow of the metal portion M causes the adjacent coil conductor layers 12a to 12c. Since a short circuit may occur between the outer glasses, it is preferable that the outer glass does not contain the filler element or is lower than the concentration of the filler element in the peripheral glass GLB.

Further, the higher the concentration of the filler element in the glass, the lower the concentration of Si in the glass, so that the concentration of Si is GLB <outer glass in the peripheral glass.
Further, in the laminated inductor component 10, the metal portions M included in the coil conductor layers 12a to 12c form a plurality of crystallites, and the average particle size of the crystallites is 0.5 μm or more and 15.0 μm or less. preferable. When the average particle size of the crystallites is 0.5 μm or more, the crystal grain boundaries that suppress the flow of current are reduced, so that the resistance of the coil 12 can be reduced. Further, when the average particle size of the crystallite is 15.0 μm or less, excessive enlargement of the crystallite is suppressed and smoothing of the outer peripheral edge of the coil conductor layers 12a to 12c is promoted.

The average particle size of the crystallites is analyzed by OIM (Orientation Imaging Microscopy), which is an image analysis device. If the measurement cannot be performed by OIM, FIB (Focused ion beam) and SIM (Scanning ion Microscopy) may be adopted for analysis.

In the latter case, as shown in FIG. 7, specifically, in the cross-sectional image of the coil conductor layers 12a to 12c, the area of the crystallite 20 of the metal portion M is calculated, and the area is a perfect circle having the same area. After calculating the diameter d and using it as the particle size, the average particle size is calculated. In calculating the average particle size, for example, five cross-sectional images of the coil conductor layers 12a to 12c are obtained from the cross section passing through the central portion of the prime field 11, and the arithmetic average of the particle size of the crystallite 20 in the images is calculated. Just do it.

Further, as a method for measuring the softening point, a portion containing each glass may be cut out as a sample from the prime field 11 or the coil conductor layers 12a to 12c, and the molten state may be confirmed with a high temperature microscope. Specifically, the sample may be heated using near infrared rays or the like while observing the sample with a high-temperature microscope in a vacuum, the softened state of the sample may be confirmed, and the point at which the softening starts may be set as the softening point.

Note that FIG. 8 is a diagram showing a state in which the firing step is completed in the embodiment of the laminated inductor component 10. In FIG. 8, the concentration of the filler element contained in the glass is expressed by shading. Except for the coil conductor layer portion, the light portion is the region where the filler element concentration is high, and the dark region is the region where the filler element concentration is low. It is an area. In the above embodiment, the insulating paste containing glass powder and the conductive paste containing metal powder and glass powder are used, and a coil conductor pattern made of the conductive paste is arranged between a plurality of insulating paste layers made of the insulating paste. A laminate was formed. Further, in the above embodiment, the laminate was fired by the firing step, and the metal powder and the glass powder were sintered into the metal portion and the glass portion, respectively. Further, in the above embodiment, the glass powder contained in the conductive paste has a lower softening point than the glass powder contained in the insulating paste.

As shown in FIG. 8, in the step of firing the laminate, the encapsulated glass GLAi (part A in FIG. 8) in which the glass powder contained in the conductive paste is encapsulated in a metal portion and sintered, and the conductive paste. The peripheral glass GLB (part B in FIG. 8) in which the glass powder contained in the above is extruded around the metal portion and sintered, and the outer glass in which the glass powder contained in the insulating paste is sintered (in C in FIG. 8). It can be seen that the part) is formed. Further, it can be seen that the concentration of the filler element is GLB> outer glass.

Further, assuming that the outermost glass in the direction orthogonal to the plane on which the coil conductor layers 12a to 12c of the element body 11 extends (the vertical direction of the paper surface in FIG. 9) is the outer layer glass, the laminated inductor component 10 is insulated. The glass contained in the body layer 18 (marker layer) becomes the outer layer glass. Here, when the concentration of Si in the peripheral glass is lower than the concentration of Si in the outer layer glass, that is, when the concentration of the above-mentioned filler element in the outer layer glass is lower than the concentration of the filler element in the peripheral glass, the element 11 is the most concentrated. The clarity of the insulating layer 18 located on the outside is improved. At this time, as shown in FIG. 10, assuming that the alignment mark 21 used for individualizing the insulator layer 18 of the mother laminate is formed, the improvement in the clarity of the insulator layer 18 results in the improvement of the clarity of the insulator layer 18. The visibility of the alignment mark 21 is improved, and the individualization accuracy is improved.

On the other hand, when the concentration of Si in the peripheral glass is higher than the concentration of Si in the outer layer glass, it becomes possible to add a filler that improves the mechanical strength in the outer layer glass, and the strength of the prime field 11 is improved.

With the multilayer inductor component configured as described above, the following effects can be obtained.
(1) The coil conductor layers 12a to 12c include a metal portion M and a glass portion GLA, and the glass portion GLA includes an encapsulated glass GLAi contained in the metal portion M. In this configuration, the surface area of the coil conductor layers 12a to 12c is increased by the inclusion glass GLAi. That is, the resistance of the coil 12 can be reduced regardless of the holes, and the above-mentioned various problems do not occur.

Further, for example, in the laminated inductor component 10, in order to improve the efficiency of obtaining inductance, the inner diameter of the coil conductor layers 12a to 12c is expanded, and the outer peripheral edge of the coil conductor layers 12a to 12c becomes the outer peripheral edge of the prime field 11. Since there are no holes in the coil conductor layers 12a to 12c even when they are close to each other, it is possible to suppress a decrease in the strength of the prime field 11.

(2) It is preferable that the cross section of the coil conductor layers 12a to 12c orthogonal to the stretching direction includes a cross section in which the ratio of the contained glass in the glass portion GLA is less than 50% in terms of area ratio. In this configuration, even with the exposed glass GLAo, the surface area of the coil conductor layers 12a to 12c is increased, so that the resistance of the coil 12 can be further reduced.

(3) It is preferable that the cross section of the coil conductor layers 12a to 12c orthogonal to the stretching direction includes a cross section in which the ratio of the encapsulated glass in the glass portion GLA is 50% or more in terms of area ratio. In this configuration, the surface area of the coil conductor layers 12a to 12c is increased, and the smoothing of the outer peripheral edge of the metal portion M of the coil conductor layers 12a to 12c is promoted. Therefore, it is possible to suppress the generation of eddy current due to the non-uniformity of the magnetic flux generation direction in the central portion of the coil 12 and reduce the loss at high frequency. In addition, it is possible to prevent a decrease in the mechanical strength of the coil 12.

(4) It is preferable that the cross section of the coil conductor layers 12a to 12c orthogonal to the stretching direction includes a cross section in which the ratio of the contained glass GLAi in the glass portion GLA is 100% in terms of area ratio. In this configuration, smoothing of the outer peripheral edge of the metal portion M of the coil conductor layers 12a to 12c is further promoted.

(5) In the cross section orthogonal to the stretching direction of the coil conductor layers 12a to 12c, the ratio of the contained glass GLAi to the coil conductor layers 12a to 12c is 1.0% or more and 20.0% or less in terms of area ratio. It is preferable that a surface is included. In this configuration, when the ratio of the contained glass GLAi is 20.0% or less, the smooth flow of the current in the coil conductor layers 12a to 12c is promoted. Further, when the ratio of the contained glass GLAi is 1.0% or more, the surface area of the coil conductor layers 12a to 12c can be increased. The area ratio mentioned above is preferably achieved in the central cross section of the longest straight line portion of the coil conductor layers 12a to 12c, and the cross section of the coil conductor layer 12a or the coil conductor layer 12b located on the outermost side. It is preferable to achieve this. In these configurations, the effect of the area ratio is most remarkable.

(6) The softening point of the peripheral glass GLB is preferably lower than the softening point of the outer glass. In this configuration, since the coil conductor layers 12a to 12c are formed in a state of being surrounded by the peripheral glass GLB which is relatively easy to soften, the smoothing of the outer peripheral edge of the coil conductor layers 12a to 12c is promoted.

(7) The softening point of the peripheral glass GLB is preferably equal to or lower than the softening point of the contained glass GLAi. In this configuration, since the coil conductor layers 12a to 12c are formed in a state of being surrounded by the peripheral glass GLB which is relatively easy to soften, the smoothing of the outer peripheral edge of the coil conductor layers 12a to 12c is promoted.

(8) The peripheral glass GLB preferably contains one or more types of filler elements, and the concentration of the filler elements is preferably higher in the peripheral glass GLB than in the outer glass. In this configuration, since the coil conductor layers 12a to 12c are formed in a state of being surrounded by the peripheral glass GLB which is relatively easy to soften, the smoothing of the outer peripheral edge of the coil conductor layers 12a to 12c is promoted.

(9) It is preferable that the concentration of Si in the peripheral glass GLB is lower than the concentration of Si in the outer glass. In this configuration, since the coil conductor layers 12a to 12c are formed in a state of being surrounded by the peripheral glass GLB which is relatively easy to soften, the smoothing of the outer peripheral edge of the coil conductor layers 12a to 12c is promoted.

(10) It is preferable that the concentration of Si in the peripheral glass GLB is lower than the concentration of Si in the outer layer glass contained in the outermost insulator layer 18. In this configuration, the clarity of the outermost portion of the prime field 11 is improved, and the visibility of the alignment mark 21 is improved, so that the individualization accuracy is improved.

(11) The concentration of Si in the peripheral glass GLB may be higher than the concentration of Si in the outer layer glass, and in this configuration, the strength of the prime field 11 is improved.
(12) The average particle size of the crystallites of the metal portion M contained in the coil conductor layers 12a to 12c is preferably 0.5 μm or more and 15.0 μm or less. In this configuration, since the crystal grain boundaries that suppress the flow of electrons are reduced, it is possible to reduce the resistance of the coil conductor layers 12a to 12c, and the excessive enlargement of the crystallites is suppressed to suppress the coil conductor layers 12a to 12a. Smoothing of the outer periphery of 12c is promoted.

(13) It is preferable that the prime field 11 is a sintered body. In this configuration, the strength of the prime field 11 is improved.
(14) The outer surface of the prime field 11 is a mounting surface 11a on which both the first external electrode 13x and the second external electrode 13y are arranged, a first end surface 11b on which only the first external electrode 13x is arranged, and a second surface. It is preferable to include the second end surface 11c in which only the external electrode 13y is arranged. In this configuration, when the laminated inductor component 10 is mounted on the board, the mounting solder forms a fillet on the first end surface 11b and the second end surface 11c, and the adhesive force of the laminated inductor component 10 to the substrate can be improved. Further, in this case, it is preferable that the mounting surface 11a, the first end surface 11b and the second end surface 11c are orthogonal to the plane (main surface of the insulator layer) on which the coil conductor layers 12a to 12c extend. In this configuration, the magnetic flux generated in the coil 12 is less likely to be blocked by the first external electrode 13x and the second external electrode 13y, and it is possible to suppress a decrease in the Q value due to eddy current loss.

(15) The softening point of the peripheral glass GLB is preferably equal to or lower than the softening point of the glass portion GLA (encapsulating glass GLAi, exposed glass GLAo). With this configuration, since the coil conductor layers 12a to 12c are formed in a state of being surrounded by the peripheral glass GLB which is relatively easy to soften, the smoothing of the outer peripheral edge of the coil conductor layers 12a to 12c is promoted.

(16) The laminated inductor component 10 uses an insulating paste containing glass powder and a conductive paste containing metal powder and glass powder, and coil conductor patterns 12a to which are made of conductive paste between a plurality of insulating paste layers made of insulating paste. The glass contained in the conductive paste comprises a step of forming a laminate in which 12c is arranged and a step of firing the laminate to sintered the metal powder and the glass powder into the metal portion M and the glass portion GLA, respectively. As the powder, a powder having a softening point lower than that of the glass powder contained in the insulating paste is used, and in the step of firing the laminate, the glass powder contained in the conductive paste is encapsulated in the metal portion M and sintered. It is preferable to use a manufacturing method in which glass powder contained in the conductive paste is extruded around the metal portion M to form a sintered peripheral glass GLB. In this method, the surface area of the coil conductor layers 12a to 12c in which the coil conductor patterns 12a to 12c are sintered by the inclusion glass GLAi and the peripheral glass GLB formed in the step of firing the laminated body is increased, and the outer peripheral edge is smoothed. The conversion is promoted.

The above embodiment may be changed as follows.
The metal portion M of the coil conductor layers 12a to 12c may be formed of a good conductor other than Ag, for example, Cu or Au. Further, the insulator layers 15a, 15b, 16a to 16c, 18 may be configured to contain ferrite, resin, or the like instead of glass. That is, the prime field 11 may be a sintered body other than glass or a sintered body other than the sintered body. If the prime field 11 is a sintered body, the strength of the prime field 11 is improved. Further, the plating applied to the external electrode is not particularly limited, and a simple substance and alloy of Sn, Ni, Ag, Cu, Pd, and Au, or a multi-layer structure in which a plurality of these are combined may be used.

The insulator layer 16, the opening 17 of the insulator layer 16, and the via 14 are formed by a manufacturing method other than photolithography, for example, crimping of an insulating material sheet, spin coating, laser processing after application of an insulating paste, or drilling. You may.

The coil conductor layers 12a to 12c preferably have a high aspect ratio t / w, which is the ratio of the width w and the thickness t in the cross section. Since the high-frequency current mainly passes through the inner side surface of the winding shape of the coil conductor layers 12a to 12c due to the skin effect, the electric resistance to the high-frequency current can be reduced if the thickness t is large. Further, when the width w is small, the inner diameter portion of the wound shape of the coil conductor layers 12a to 12c can be relatively widened, and the inductance acquisition efficiency can be improved.

The shape of the external electrode is not particularly limited, and may be a shape formed on the first end surface and its adjacent four surfaces, the second end surface and its adjacent four surfaces, or formed only on the mounting surface. It may be in shape.

-The relationship between the stacking direction and the mounting surface is not particularly limited, and the stacking direction and the mounting surface may be orthogonal to each other.
The external size is not particularly limited, and may be a size such as 1005, 0804, 0603, 0402, or any other ratio based on the longitudinal dimension and the lateral dimension on the mounting surface, for example. Further, the height dimension is arbitrary and may be the same as the longitudinal dimension or the lateral dimension, or may be a dimension different from these.

The technical ideas that can be derived from the above embodiments and modifications are listed.
A coil having an element body which is an insulator and a coil in which a plurality of coil conductor layers extending along a plane in the element body are electrically connected, and the coil conductor layer has a metal portion and a glass portion. The glass portion includes, and the laminated inductor component including the encapsulated glass contained in the metal portion.

A base body that is an insulator and a coil in which a plurality of coil conductor layers extending along a plane in the base body are electrically connected are provided, and the coil conductor layer has a metal portion and a glass portion. The peripheral glass includes glass, and the glass of the element body within 10 μm around the coil conductor layer is defined as peripheral glass, and the glass of the element body further outside the peripheral glass is defined as outer glass. The softening point of the laminated glass is lower than the softening point of the outer glass.

-Using an insulating paste containing glass powder and a conductive paste containing metal powder and glass powder, a laminate in which a coil conductor pattern composed of the conductive paste is arranged between a plurality of insulating paste layers composed of the insulating paste is formed. A step of firing the laminate and sintering the metal powder and the glass powder into a metal portion and a glass portion, respectively, is provided, and the glass powder contained in the conductive paste includes the insulating paste. In the step of firing the laminate using a material having a softening point lower than that of the glass powder contained in the above, the encapsulating glass in which the glass powder contained in the conductive paste is encapsulated in the metal portion and sintered. A method for manufacturing a laminated inductor component in which the glass powder contained in the conductive paste is extruded around the metal portion to form a sintered peripheral glass.

11 ... prime field, 12 ... coil, 13 ... external electrode, 14 ... via, 15a, 15b ... insulator layer / insulation paste layer for outer layer, 16a-16d ... insulator layer / insulation paste layer, 20 ... crystallite, GLAi ... Inclusion glass, GLAo ... Exposed glass, GLB ... Peripheral glass.

Claims (6)

The prime field, which is an insulator,
A coil in which a plurality of coil conductor layers extending along a plane in the element body are electrically connected to each other.
The coil conductor layer includes a metal portion and a glass portion, and includes a metal portion and a glass portion.
The prime field contains glass and contains glass.
Assuming that the glass of the element body within 10 μm around the coil conductor layer is the peripheral glass and the glass of the element body further outside the peripheral glass is the outer glass, the peripheral glass is Bi, Li, Na, K, Mg. , Ca, Sr, Ba, Co, Zn, B, Pb, Al, Zr, P, V. Higher than glass,
Multilayer inductor component. In the laminated inductor component according to claim 1,
The concentration of Si in the peripheral glass is lower than the concentration of Si in the outer glass.
Multilayer inductor component. In the laminated inductor component according to claim 1,
Assuming that the outermost glass in the direction orthogonal to the plane on which the coil conductor layer of the prime field extends is the outer layer glass,
The concentration of Si in the peripheral glass is lower than the concentration of Si in the outer layer glass.
Multilayer inductor component. The laminated inductor component according to any one of claims 1 to 3.
The metal portion included in the plurality of coil conductor layers forms a plurality of crystallites, and the average particle size of the plurality of crystallites is 0.5 μm or more and 15.0 μm or less.
Multilayer inductor component. The laminated inductor component according to any one of claims 1 to 4.
The prime field is a sintered body.
Multilayer inductor component. The laminated inductor component according to any one of claims 1 to 5.
Further, it is provided with a first external electrode and a second external electrode arranged along the outer surface of the prime field and electrically connected to the first end and the second end of the coil, respectively.
As the outer surface, a mounting surface on which both the first external electrode and the second external electrode are arranged, a first end surface on which only the first external electrode is arranged, and only the second external electrode are arranged. The mounting surface, the first end surface, and the second end surface include the second end surface, and the first end surface and the second end surface are orthogonal to the plane on which the coil conductor layer extends.
Multilayer inductor component.

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