JP2000306729A - Stacked coil device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the stacked coil device which can be manufactured through a filming process for a metal film composed of two layers, has a large electromagnetic coupling coefficient, and is reducible in manufacturing cost. SOLUTION: A 1st and a 2nd coil are divided into a square-shaped spiral lower-layer coil (shown by broken lines) and an upper-layer coil (shown by solid lines) across an insulating layer. The path of the 1st coil extends in the order to a lower-layer lead-out terminal 1e, a lower-layer lead-out line 1b, a lower-layer coil 1a, an upper-layer coil 1c, an upper-layer lead-out line 1d, and an upper-layer lead-out terminal 1f. The path of the 2nd coil extends in the order of an upper-layer lead-out electrode 2f, an upper-layer lead-out line 2d, a lower-layer coil 2a, an upper-layer coil 2c, a lower-layer lead-out line 2b, and a lower-layer lead-out terminal 2e. Then a single-coil part, where the coil of the lower layer and the coil of the upper layer do not face each other vertically, is arranged on one of the diagonals of a square spiral coil surface as shown by the dot-set part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a laminated coil device such as a transformer and a common mode choke coil.

[0002]

2. Description of the Related Art As a conventional laminated coil device, there is a laminated transformer having a three-layer structure as shown in FIG. In this conventional laminated transformer, a pair of spiral rectangular coils 21 and 22 vertically facing each other via an insulating layer (not shown) are formed on a substrate 23. And the coils 21 and 22
Are connected to the extraction terminals 21a and 22a, respectively. Also, the inner terminals 21c of the coils 21 and 22,
Reference numeral 22c is connected to the lead terminals 21b and 22b via an insulating layer.

[0003] This conventional laminated type transformer has an extraction terminal 2
It is formed by processing a three-layer metal film composed of 1b, 22b, the lower coil 22, and the upper coil 21.

[0004]

However, in the conventional laminated transformer as the conventional laminated coil device, since the upper and lower coils 21 and 22 are formed facing each other, the electromagnetic coupling coefficient is large and the leakage magnetic flux is reduced. It is characterized by a small amount and high power transmission or conversion efficiency, but has the disadvantage that the metal film consisting of three layers must be formed, so that there are many film forming steps and the cost is high. Was.

Accordingly, an object of the present invention is to provide a laminated coil device which can be manufactured by a process of forming a two-layer metal film, has a large electromagnetic coupling coefficient, and can reduce the manufacturing cost. And

[0006]

According to a first aspect of the present invention, the first coil and the second coil are each formed of a spiral coil portion divided into an upper layer and a lower layer via an insulating layer. (A first upper / lower layer coil, a second upper / lower layer coil) and a lead portion (a first upper / lower layer lead, a second upper / lower layer lead), and the first coil is a first lower layer coil. A first lower layer lead is integrally connected to the outer end, a first upper layer lead is integrally connected to the outer end of the first upper coil,
The first lower layer coil and the inner end of the first upper layer coil are connected by a through-hole line, and the second coil has a second upper layer lead wire connected to the outer end of the second lower layer coil through the through-hole line. A second lower-layer lead wire is connected to the outer end of the second upper-layer coil through a through-hole wire;
The inner end of the upper coil is connected by a through-hole wire, and the first coil and the second coil are arranged so that their upper and lower coils and the lead wire overlap one another up and down. The terminals are connected.

According to the present invention, the first coil and the second coil are arranged so as to be parallel to each other at a constant interval in the same layer, and to be vertically overlapped in different layers via an insulating layer. The first coil and the second coil each include a spiral coil portion and a lead wire portion.

The first coil and the second coil are composed of two spiral coils, the upper coil and the lower coil.
Although they are divided and formed in layers, they have different shapes and arrangements of the lead lines. That is, the first upper-layer coil is connected to the first upper-layer lead wire on the same surface. Further, the first lower layer coil is connected to the first lower layer lead wire on the same surface.

On the other hand, in the second coil, the lead connected to the second upper layer coil is formed in the lower layer, and becomes the second lower layer lead. The lead connected to the second lower-layer coil is formed in the upper layer, and becomes the second upper-layer lead.

According to the present invention, the first coil and the second coil are formed so as to overlap in the upper and lower layers.
When this is used for a transformer, the first coil and the second coil
The coupling of the electromagnetic field between the coils is increased, and high-frequency noise in the normal mode can be reduced. In addition, by forming the first coil and the second coil to have equal lengths and forming the upper and lower layer coils in a spiral coil shape, common mode noise is suppressed.

According to a second aspect of the present invention, in the laminated coil device according to the first aspect, the first coil and the second coil are formed such that a single coil portion which does not overlap vertically has a rectangular spiral coil surface. It is characterized by being formed on one diagonal line.

According to the present invention, two paired coils of a first coil and a second coil running in parallel are spirally formed in two layers, upper and lower layers.
When the lead terminals are led out of the paired coils by being formed so as to be overlapped with each other, a portion where the paired coils cross each other or a portion where the paired coils do not overlap each other, that is, a single coil portion is necessarily generated.
According to the present invention, the single coil portion is geometrically arranged in a minimum necessary shape, and is arranged in one direction turning portion of each spiral coil, that is, on one diagonal line of the spiral coil surface. As a result, the length (area) of the vertically overlapping portion of the paired coils is maximized (increased), in other words, the length (area) of the non-overlapping portion is minimized (decreased).
Then, the electromagnetic coupling between the first coil and the second coil is increased to reduce the impedance of the normal mode high frequency noise and increase the impedance of the common mode high frequency noise.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A laminated transformer will be described below as an embodiment of the laminated coil device of the present invention with reference to the drawings. In FIG. 1, reference numeral 10 denotes a rectangular insulating substrate made of alumina porcelain, glass, or the like. A metal film of silver (Ag) having a thickness of 0.1 to 100 μm is formed on the upper surface of the insulating substrate 10 by a film forming means such as a sputtering method.

Next, the metal film is photo-etched using a photolithography technique and an etching technique so as to be kept in a rectangular spiral shape at a constant distance from each other, and to be wound clockwise from the center to the outside. A pair of a first lower layer coil 1a and a second lower layer coil 2a, a first lower layer lead wire 1b integrally connected to an outer end of the first lower layer coil 1a and extending in a direction opposite to the outer end, The first lower layer connected integrally to the first lower layer lead wire 1b
A lead terminal 1e, a second lower lead line 2b which is disposed on the opposite side of the first lead terminal 1e and is not connected independently, and a lower second lead line integrally connected to the second lower lead line 2b. The lead terminals 2e are formed.

Next, on the first lower coil 1a, the second lower coil 2a and the like, an insulating thin film 3 made of a photosensitive polyimide resin or the like having a thickness of about 5 μm is formed by spin coating. Then, two through holes 3 for through hole lines are formed in the center of the insulating thin film 3 by using a photolithography technique.
e, 3f and through-holes 3c, 3d for through-hole wires are formed at upper and lower corners on one diagonal of the spiral winding. Next, a film is formed on the upper surface of the insulating thin film 3 by sputtering. A metal film made of silver (Ag) having a thickness of 1 to 10 μm is formed.

Next, the metal film is photo-etched using a photolithography technique and an etching technique so as to be kept in a rectangular spiral shape at a constant distance from each other, and to be wound counterclockwise from the center toward the outside. And
A pair of a first upper layer coil 1c and a second upper layer coil 2c,
A first upper lead 1 integrally connected to an outer end of the first upper coil 1c and extending from the outer end similarly in the counterclockwise direction.
d, a first lead-out terminal 1f integrally connected to the first upper-layer lead-out line 1d, and a second upper-layer lead-out line 2d arranged on the opposite side of the first lead-out terminal 1f and independently unconnected. And an upper second lead-out terminal 2f integrally connected to the second upper-layer lead 2d.

In the second sputtering of the metal film for forming the first upper coil 1c, the second upper coil 2c, etc., the inner end 1g of the lower first lower coil 1a is formed.
Is connected to the inner end 1h of the upper first coil 1c via a through hole 3e of the insulating thin film 3 by a through hole wire. The inner end 2g of the lower second coil 2a
Is connected to the inner end 2h of the upper second coil 2c via a through hole 3f of the insulating thin film 3 by a through hole wire.

Further, the end 2i of the lower second lower layer lead wire 2b and the outer end 2j of the upper second coil 2c are
They are connected by through-hole wires via through-holes 3c of the insulating thin film 3. Also, the outer end 2k of the lower second coil 2a
And the end 2m of the upper second-layer lead wire 2d is an insulating thin film 3.
Are connected by through-hole lines through the through-holes 3d.

As shown in FIG. 2, the first lower coil 1a of the first coil, the first upper coil 1c, and the second upper coil 2c and the second lower coil 2a of the second coil are vertically overlapped with each other. Laminated. In addition, the first lower layer lead 1b and the first upper layer lead 1d of the first coil and the second upper layer lead 2d and the second lower layer lead 2b of the second coil are stacked so as to overlap each other.

The first coils 1, 1 '(first lower layer coil 1a + first lower layer lead 1b + first upper layer coil 1c + first upper layer lead 1d) and second coils 2, 2' (second lower layer coil 2a + 2nd lower layer lead wire 2b + second upper layer coil 2c +
The second upper layer lead wire 2d) is formed to have a uniform coil length.

The winding direction of the first coil 1 (1 ') and the second coil 2 (2') is clockwise or counterclockwise as long as the coils can be tightly coupled vertically to realize an equal length. It may be clockwise.

As the metal film material, silver (A
Other than g), metals such as Au (gold), copper (Cu), and aluminum (Al) may be used.

The metal film may be formed by a vapor deposition method, a plating method, a CVD method, a screen printing method or the like, in addition to the sputtering method.

Next, a protective film 4 made of a polyimide resin or the like having a thickness of about 100 μm is spin-coated on the exposed insulating thin film 3 on the first upper coil 1c, the second upper coil 2c, etc. It is formed by a screen printing method or the like. And, as described above, FIG. 2 shows a mode of lamination of the upper coil layer and the lower coil layer. In FIG. 2, the insulating thin film 3 and the like interposed between the upper and lower coil layers are removed, and then the first coil and the second coil which are divided and wound into an upper coil layer and a lower coil layer. The path between the lead terminals of the coil will be described with reference to FIGS.
At this time, the path of the coil is indicated by an arrow.

In FIG. 3, the first coil is a lower first layer.
Assuming that the terminal starts from the lead terminal 1e, the first terminal extending rightward
After passing through the lower layer lead wire 1b, the coil enters the first lower layer coil 1a and is wound in a counterclockwise direction.
e), through the inner end 1h of the first upper coil 1c,
After entering the upper coil 1c, it is similarly wound counterclockwise, and reaches the upper first lead terminal 1f via the first upper lead wire 1d connected to the first upper coil 1c.

Next, in FIG. 4, assuming that the second coil starts from the lower second lead-out terminal 2e, the second coil extends through the second lower-layer lead 2b extending to the left, its end 2i, the through-hole line (3c). , Through the end 2j of the upper second coil 2c, enters the second upper coil 2c and winds it clockwise, its inner end 2h, the through-hole wire (3f), the second lower coil 2a.
The coil enters the second lower coil 2a through the inner end 2g, and is similarly wound clockwise, passes through the outer end 2k, the through hole line (3d), and the end 2m of the second upper layer lead 2d. Second
The upper layer lead wire 2d enters and reaches the upper layer second lead terminal 2f.

Next, FIG. 5 shows that the lower coil shown by the broken line and the upper coil shown by the solid line are slightly deliberately shifted,
FIG. 3 shows the overlapping relationship between the upper and lower coils.
FIG. 5 is a schematic diagram when a current (normal mode current) in the direction indicated by the same arrow as the path of the coil shown in FIG. 4 flows through the first coil and the second coil. In the figure, a portion surrounded by coils on four sides that define a painted portion is a first portion.
The coil and the upper and lower layer coils of the second coil overlap each other to form a single coil instead of a double coil. This single coil portion is formed on one diagonal line of the spiral coil surface except for the upper right one. In FIG. 6, unlike FIG. 5, the solid portion indicates a double coil portion (area) where the upper and lower layer coils of the first coil and the second coil overlap.

Since the electromagnetic coupling coefficient is reduced by the single coil portion, the impedance of normal mode high frequency noise is increased. Further, since the single coil portion promotes the non-uniformity of the first coil and the second coil and cannot completely cancel the common mode noise, the loop coil length (area) of the single coil portion is short. (Small) is desirable. In the present embodiment, the length (area) of the single coil portion is reduced by providing the single coil portion on one diagonal line of the spiral coil surface so that the electromagnetic coupling between the first coil and the second coil is reduced. Loss can be reduced.

According to the first aspect of the present invention, the first coil, the second coil, and the lead-out terminal are composed of upper and lower layers while maintaining a high electromagnetic coupling coefficient between the first coil and the second coil. Therefore, the number of process steps can be reduced and the manufacturing time of the coil device can be reduced as compared with the conventional coil device having a three-layer structure, so that the manufacturing cost can be reduced.

According to a second aspect of the present invention, a single coil portion of a pair coil comprising a first coil and a second coil, which does not overlap vertically, is arranged on one diagonal line of a spiral coil surface, and a coil of a portion which vertically overlaps the pair coil is arranged. Length (area)
Is reduced, the electromagnetic coupling coefficient can be maximized, and the residual inductance can be minimized. As a result, high-frequency noise in normal mode can be reduced and common mode noise can be suppressed.

[Brief description of the drawings]

FIG. 1 is a developed perspective view showing a manufacturing process of a multilayer transformer according to an embodiment of the multilayer coil device of the present invention.

FIG. 2 is a perspective view showing an overlapping arrangement relationship between an upper coil and a lower coil manufactured by the manufacturing process shown in FIG. 1;

FIG. 3 is a diagram showing a path between an upper coil and a lower coil of a first coil;

FIG. 4 is a diagram showing a path between an upper coil and a lower coil of a second coil;

FIG. 5 is a diagram showing a single coil portion in which an upper coil and a lower coil are not vertically overlapped;

FIG. 6 is a diagram showing a double coil portion in which an upper coil and a lower coil are vertically overlapped;

FIG. 7 is a perspective view of a multilayer transformer as a conventional multilayer coil device.

[Explanation of symbols]

 1, 1 'First coil 1a First lower layer coil 1b First lower layer lead 1c First upper layer coil 1d First upper layer lead 1e First lead terminal 1f First lead terminal 1g, 1h Inner end 2, 2' 2 coil 2a 2nd lower layer coil 2b 2nd lower layer lead 2c 2nd upper layer coil 2d 2nd upper layer lead 2e 2nd lead terminal 2f 2nd lead terminal 2g ~ 2m End part 3 Insulating thin film 3c ~ 3f Through hole 10 Insulating substrate

Claims (2)

[Claims] 1. A spiral coil portion (first upper / lower layer coil, second upper / lower layer) formed by dividing a first coil and a second coil into two layers of an upper layer and a lower layer via an insulating layer. Coil) and a lead wire portion (first upper / lower lead wire, second upper / lower lead wire), and the first coil has the first lower lead wire integrally connected to the outer end of the first lower coil. A first upper-layer lead wire is integrally connected to an outer end of the first upper-layer coil, and an inner end of the first lower-layer coil and the first upper-layer coil are connected by a through-hole wire. A second upper-layer lead wire is connected to the outer end of the second lower-layer coil via a through-hole line, and a second lower-layer lead wire is connected to the outer end of the second lower-layer coil via a through-hole line;
Then, the inner ends of the second lower coil and the second upper coil are connected by through-hole wires, and the first coil and the second coil are arranged such that the upper / lower coil and the lead wire are vertically overlapped. And a laminated coil device in which an external lead terminal is connected to the lead wire. 2. The laminated coil device according to claim 1, wherein the first coil and the second coil are formed such that a single coil portion that does not vertically overlap is formed on one diagonal of a rectangular spiral coil surface. A laminated coil device.