WO2015097728A1

WO2015097728A1 - Coil part

Info

Publication number: WO2015097728A1
Application number: PCT/JP2013/007676
Authority: WO
Inventors: 佐野　孝史; 常徳寺田
Original assignee: 株式会社Ｌｅａｐ
Priority date: 2013-12-27
Filing date: 2013-12-27
Publication date: 2015-07-02
Also published as: JP5584844B1; JPWO2015097728A1; TW201546842A

Abstract

First resin substrates and second resin substrates are adhered while being layered alternating in such a way that a front surface and a back surface are facing each other to form a layered form in which a first coil element and a second coil element are overlapped while alternating. A second end of a first coil element present in a lower layer and a first end of a second coil element present in an upper layer are electrically connected via a through-hole provided at a first end of the second resin substrate present in the upper layer. The first end of a first coil element present in an upper layer and the second end of a second coil element present in a lower layer are electrically connected via a through-hole provided at a first end of the first resin substrate present in the upper layer. In this way, a power inductor is constituted, wherein alternating first coil elements and second coil elements are connected in series within the layered form. From the first end of the first coil element formed in the first resin substrate present in the lowest layer, and from the second end of the second coil element formed in the second resin substrate present in the topmost layer, electrodes are drawn outside of the layered form to serve as electrodes for the power inductor.

Description

Coil parts

The present invention relates to a coil component produced in a resin substrate, and more particularly to a coil component configured by laminating a plurality of resin substrates.

With the recent increase in functionality of mobile devices such as smartphones and tablet terminals, the need for small, high-inductance, high-current coil components (power inductors) is increasing.

As a method for producing a power inductor, a plurality of resin substrates each having a patterned coil element are prepared, and these coil elements formed on each resin substrate are stacked and connected in series. It is common to make them.

In Patent Document 1, a resin intaglio having irregularities corresponding to a conductor pattern of a coil element is filled with a conductive paste, the pattern of the filled conductive paste is transferred to a ceramic substrate, and N (N is It is described that a coil component is produced by laminating two layers.
Further, Patent Document 2 describes that a chip coil is manufactured by laminating a plurality of sheet-like laminates having coil conductors formed on both surfaces.

JP 2003-68555 A JP 2006-332147 A

The coil parts described in

Patent Documents

1 and 2 described above have a complicated via connection structure between the coil elements formed in each layer and have a large bonding area between the coil elements in each layer. There is a problem that the occupied area of becomes large.
Moreover, since the thickness per layer is large, when the laminated coil components are produced, there is also a problem that the entire thickness is further increased.

The present invention has been made to solve the above-described problem, and by simply laminating a resin substrate having a coil element formed by stamping, each coil element is alternately connected in series to constitute a power inductor. An object is to provide a small coil component having a small chip area and a thin laminated thickness.

The above-described problems can be achieved by the following present invention.

In the coil component of the present invention, a first coil element pattern wound in a spiral shape in the clockwise (or counterclockwise) direction from one end to the other end is imprinted on the surface at a predetermined depth, A first resin substrate on which the first coil element pattern engraved is filled with a conductive layer by electroplating to form the first coil element, and outward in the clockwise (or counterclockwise) direction from one end to the other end. The second coil element pattern wound in a spiral shape is engraved on the surface at a predetermined depth, and the engraved second coil element pattern is filled with a conductive layer by electroplating to form a second coil element. The first resin element and the second resin element are alternately laminated and bonded so that the front surface and the rear surface face each other. Superimposed laminated molded body And electrically connecting the other end of the first coil element in the lower layer and one end of the second coil element in the upper layer through a through hole provided in one end of the second resin substrate in the upper layer. One end of a certain first coil element and the other end of the second coil element in the lower layer are electrically connected through a through hole provided in one end of the first resin substrate in the upper layer, and the first coil element is formed in the laminated molded body. A power inductor in which coil elements and second coil elements are alternately connected in series is formed, and is formed on one end of the first coil element formed on the first resin substrate in the lowermost layer and on the second resin substrate in the uppermost layer. An electrode is drawn out of the laminated molded body from the other end of the second coil element thus formed, and used as a power inductor electrode.

Further, in the coil component of the present invention, the first position and the second position of the first resin substrate in the lowermost layer are imprinted through the substrate and filled with the conductive layer by electroplating. And a second electrode, and a second electrode of the first resin substrate and the second resin substrate in the upper layer is imprinted through the substrate and filled with a conductive layer by electroplating Are arranged, and the through electrodes of each layer are connected to each other and electrically connected to the second electrode in the lowermost layer, and one end of the first coil element formed on the first resin substrate in the lowermost layer is connected to the first electrode The other end of the second coil element formed on the second resin substrate on the uppermost layer is connected to the through electrode, and the first electrode and the second electrode are used as power inductor electrodes. It is characterized by that.

The coil component according to the present invention is characterized in that the first and second resin substrates are made of a thermosetting resin.

According to the present invention, a power inductor having a sufficiently small thickness and a small chip area can be obtained.

FIG. 3 is a structural diagram of a lowermost resin substrate according to the present invention. FIG. 3 is a structural diagram of an even-numbered resin substrate according to the present invention. FIG. 3 is a structural diagram of an odd-numbered resin substrate according to the present invention. FIG. 3 is a structural diagram of the uppermost resin substrate according to the present invention. FIG. 3 is an exploded perspective view of laminated coil elements according to the present invention. The process flow figure which shows the preparation procedure of a 1st metal mold | die. The figure which shows the structure of a 2nd metal mold | die. The manufacturing process flow figure of a resin substrate.

Hereinafter, embodiments of the coil component of the present invention will be described in detail with reference to the accompanying drawings.

The coil component according to the present invention has a structure of a laminated molded body in which a plurality of resin substrates on which coil elements are formed are laminated and bonded. Coil elements formed in each resin substrate are connected in series between the layers via a through hole to form a power inductor, formed on one end of the coil element formed on the resin substrate in the lowermost layer and the resin substrate in the uppermost layer The other end of the coil element thus formed is drawn out of the laminated molded body and used as an electrode of a power inductor. The number of resin substrates stacked 2N (N is an integer) is not limited, but in the following embodiments, the case of N = 4, that is, the case of eight layers will be described.

1 to 4 are a plan view (a) and sectional views (b) and (c) showing the structure of a resin substrate on which a coil element is formed. FIG. 1 shows the first layer (lowermost layer), and FIG. , 4 and 6, FIG. 3 shows the third, fifth and seventh layers, and FIG. 4 shows the eighth (uppermost) resin substrate.

FIG. 1 shows the structure of the first (lowermost) resin substrate 100. (A) is a plan view, (b) is a sectional view taken along line AA in (a), and (c) is a sectional view taken along line BB in (a).
A first coil element pattern wound spirally inward in the clockwise direction from one end 102 to the other end 104 is engraved on the surface of the resin substrate 100 at a predetermined depth (d1). The first coil element pattern is filled with a conductive layer by electroplating to form the first coil element 106. In addition, the first position I and the second position II of the resin substrate 100 are stamped (d2) through the substrate and filled with a conductive layer by electroplating, and the second electrode 110 are arranged. Note that one end 102 of the first coil element 106 is connected to the first electrode 108.

A rectangular opening 120 penetrating the substrate is formed at the center of the resin substrate 100.
A laminated molded body is formed in the opening 120, and when it is attached to the printed wiring board, other electronic components can be arranged.
Note that the winding direction of the first coil element 106 may be counterclockwise. The line width and film thickness of the first coil element 106 can be 40 μm, the thickness of the resin substrate can be 50 μm, and the size can be about 3.0 mm × 4.0 mm. The line width of the other end 104 of the first coil element 106 is preferably increased to about 80 to 100 μm so as to be connected to one end of the second coil element formed on the upper resin substrate.

FIG. 2 shows the structure of an even-numbered (2, 4, 6) -thick resin substrate 200 excluding the eighth (uppermost) layer. (A) is a plan view, (b) is a sectional view taken along line CC of (a), and (c) is a sectional view taken along line DD of (a).
A second coil element pattern wound spirally from the one end 202 to the other end 204 in the clockwise direction is engraved on the surface of the resin substrate 200 at a predetermined depth (d1). The second coil element pattern is filled with a conductive layer by electroplating to form a second coil element 206. In addition, a penetrating electrode 208 that is imprinted (d2) through the substrate and filled with a conductive layer by electroplating is disposed at the second position II of the resin substrate 200. One end 202 is provided with a through hole 210 penetrating the substrate, and the through hole 210 is filled with a conductive layer by electroplating.
Note that the winding direction of the second coil element 206 is the same as the winding direction of the first coil 106.

In the following description, odd-numbered resin substrates and coil elements are referred to as first resin substrates and first coil elements, respectively, and even-numbered resin substrates and coil elements are referred to as second resin substrates and second coil elements, respectively. I will call it.
Here, the first resin substrate 100 shown in FIG. 1 and the second resin substrate shown in FIG. 2 are laminated and bonded so that the front surface 100F of the first resin substrate 100 and the back surface 200R of the second resin substrate 200 face each other. Let Then, the other end 104 of the first coil element 106 in the lower layer and one end 202 of the second coil element in the upper layer are electrically connected via the through hole 210 provided in the one end 202 of the second resin substrate 200, The second electrode 110 at the second position II of the first resin substrate 100 and the through electrode 208 at the second position II of the first resin substrate 200 are also electrically connected. In order to make the electrical connection more reliable, solder bumps may be formed on the respective connection portions and then welded.

FIG. 3 shows the structure of the first resin substrate 100a of odd-numbered layers (3, 5, and 7 layers) excluding the first layer. (A) is a plan view, (b) is a sectional view taken along line EE of (a), and (c) is a sectional view taken along line FF of (a). Although the element arrangement is almost the same as that of the first resin substrate 100 of the first layer shown in FIG. 1, the position of one end 102a of the first coil element 106a is different, and the through hole 112a is connected to the one end 102a. And the configuration is slightly different in that no electrode is provided at the first position I.
Here, the front surface 200F of the second resin substrate 200 shown in FIG. 2 and the back surface 100aR of the first resin substrate 100a shown in FIG. Then, the other end 204 of the second coil element 206 in the lower layer and the one end 102a of the first coil element 106a in the upper layer are electrically connected via the through hole 112a, and the first resin substrate 100a in the upper layer is first connected. The through electrode 110a at the second position II and the through electrode 208 at the second position II of the lower second resin substrate 200 are also electrically connected.

FIG. 4 shows the structure of the second resin substrate 200a in the eighth layer (uppermost layer). (A) is a plan view, (b) is a sectional view taken along line GG in (a), and (c) is a sectional view taken along line HH in (a).
Although the element arrangement is almost the same as that of the second resin substrate 200 in the second, fourth, and sixth layers shown in FIG. 2, the position of the other end 204a of the second coil element 206a is different from the other end 204a. The configuration is slightly different in that it is connected and a through hole 208a is provided.
Here, the front surface 100aF of the first resin substrate 100a shown in FIG. 3 and the back surface 200aR of the second resin substrate 200a shown in FIG. 4 are laminated and bonded together. Then, the other end 104a of the first coil element 106a in the lower layer and one end 202a of the second coil element 206a in the uppermost layer are electrically connected via the through hole 210a, and the second resin substrate 200a in the uppermost layer is connected. The through hole 208a at the second position II is also electrically connected to the through electrode 110a at the second position II of the first resin substrate 100a in the lower layer.

In this way, a laminated molded body composed of eight layers is configured, and the first electrode 108 at the first position I and the second electrode 110 at the second position II of the first resin substrate 100 in the lowermost layer. Are drawn out of the laminated molded body as both electrodes of a power inductor configured by alternately connecting four first coil elements and four second coil elements in series.

FIG. 5 is an exploded perspective view showing the arrangement by taking out the coil elements and the electrodes of the coil component produced as described above.
Both

electrodes

108 and 110 of the power inductor are taken out from the back surface 100R of the lowermost first resin substrate 100 and connected to electrodes (not shown) provided on the printed wiring board 300.
In the above description, it has been described that a single coil component is manufactured. However, actually, the first and second resin substrates are formed with a plurality of coil elements arranged in a matrix. After lamination, they are separated by dicing to form a single coil component.
Moreover, in the coil component according to the present invention, the resin substrate is used as it is after the coil element and the power inductor are formed. As the resin material, a thermosetting resin such as epoxy, phenol, polyimide, or polyurethane can be used. The electroplating for forming the conductive layer is preferably copper plating.

Next, an example of a production method in the case of producing a coil component using a resin mold made of a thermosetting material will be described.
In this manufacturing method, the first mold having the reverse coil element pattern 35 and the reverse through hole pattern 45 formed by reversing the coil element pattern 30 and the through hole pattern 40 on the surface, and the side wall portion are formed. A desired resin mold and a resin substrate are produced by using a combination of a mold that defines and a second mold that includes a mold that defines a bottom surface portion.

FIG. 6 is a process flow diagram showing the procedure for producing the first mold.
First, as shown in FIG. 6a, a metal mold 1 made of Ni, SUS, Ni alloy or the like having a coil element pattern 30 having a depth d1 and a through-hole pattern 40 having a depth d2 imprinted on the surface thereof is prepared. Next, as shown in FIG. 6 b, a release layer such as NiO is formed on the surface of the mold 1, and then Ni is laminated and transferred by electroplating to produce the Ni mold 2. Thereafter, the Ni mold 2 is peeled off from the metal mold 1 to form a first mold 2 as shown in FIG.
As a result, a reverse coil element pattern 35 having a height d1 and a reverse through-hole pattern 45 having a height d2 are formed on the surface of the first mold 2.

FIG. 7 is a diagram showing the configuration of the second mold. The second mold is called a casting mold, and is formed by bonding a mold 4 that defines a side wall portion and a mold 3 that defines a bottom surface portion. The material of the mold 4 is not particularly limited, and may be a resin or a metal. As a material of the mold 3, it is necessary to have low cost, a seed layer for a plating process in a later step can be formed on the surface, and a thin layer for peeling or dissolving. It is preferable to use a resin such as acrylic.

FIG. 8 is a diagram showing a process flow for producing the resin substrate 5 using the first mold 2 shown in FIG. 6 and the second mold shown in FIG.
First, as shown in FIG. 8 a, the first mold 2 is placed in the second mold into which the casting resin film F has been poured so that the reverse through-hole pattern 45 is in close contact with the bottom surface of the casting mold 3. And pressurize.
At this time, the reverse through-hole pattern 45 is sufficiently adhered to the bottom surface portion of the casting mold 3 so that the resin film F does not enter the adhesion portion. The resin film F is uniformly filled in the recesses of the first mold 2 and then cured.
Thereafter, when the first mold 2 is removed, the resin mold 5 having the coil element pattern 30 and the through-hole pattern 40 is produced on the casting mold 3 as shown in FIG. Thereafter, as shown in FIG. 8c, the casting mold 4 defining the side wall portion of the second mold is removed.
Next, when the seed layer is formed in the region of the coil element pattern 30 and the region of the through-hole pattern 40 and the pattern portion is filled with a conductive layer by electroplating, the coil element 30a and the through-hole 40a are made of resin as shown in FIG. It is formed in the mold 5.
Finally, when the casting mold 3 is peeled from the resin mold 5, a resin substrate is completed as shown in FIG. 8e.

In the resin substrate described above, the resin mold is produced by the first mold and the second mold. However, the coil element pattern and the through hole pattern are formed directly on the resin substrate by imprinting or hot pressing. It is also possible to engrave a resin mold.

102a One end of the first coil element 106a 104 Other end of the first coil element 106a 104a Other end of the first coil element 106a 106, 106a First coil element 108 First electrode 110 Second electrode 110a Through electrode 202 Second coil One end of element 202a One end of second coil element 206a in the uppermost layer 204 Other end of second coil element 206 in the lower layer 206 Second coil element in the lower layer 206a Second coil element in the uppermost layer 208 Through electrode 208a Through hole 300 Printed circuit board

Claims

A first coil element pattern wound spirally inward in the clockwise (or counterclockwise) direction from one end to the other is stamped on the surface at a predetermined depth, and the first stamped A first resin substrate in which a coil element pattern is filled with a conductive layer by electroplating to form a first coil element;
A second coil element pattern wound in a spiral shape from one end to the other end in a clockwise (or counterclockwise) direction is engraved on the surface at a predetermined depth, and the engraved second pattern A second resin substrate in which a coil element pattern is filled with a conductive layer by electroplating to form a second coil element, and
A laminated molded body in which the first coil element and the second coil element are alternately stacked and bonded so that the front surface and the back surface are opposed to each other, and the first coil element and the second coil element are alternately superimposed. The other end of the first coil element in the lower layer and the one end of the second coil element in the upper layer are electrically connected through a through hole provided in the one end of the second resin substrate in the upper layer. The one end of the first coil element in the upper layer and the other end of the second coil element in the lower layer through a through hole provided in the one end of the first resin substrate in the upper layer. Electrically connected to form a power inductor in which the first coil elements and the second coil elements are alternately connected in series in the laminated molded body, and formed on the first resin substrate in the lowermost layer On the one end and the uppermost layer of the first coil element The other end of the pull out the electrode in the stacking molding external coil component, characterized in that the electrodes of the power inductor of said formed in the second resin substrate and the second coil element.
The first position and the second position of the first resin substrate in the lowermost layer are engraved through the substrate and filled with a conductive layer by electroplating, and the second electrode And a through electrode embedded in the conductive layer by electroplating is disposed at the second position of the first resin substrate and the second resin substrate in the upper layer, and is laminated. Sometimes the through electrodes of each layer are connected to each other and electrically connected to the second electrode in the lowermost layer, and the one end of the first coil element formed on the first resin substrate in the lowermost layer is connected to the first electrode. The other end of the second coil element formed on the second resin substrate in the uppermost layer is connected to the through electrode, and the first electrode and the second electrode are connected to the first electrode. The coil according to claim 1, wherein the coil is an electrode of the power inductor. Goods.
The coil component according to claim 1, wherein the first and second resin substrates are made of a thermosetting resin.