JP3073028B2 - LC noise filter and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LC noise filter, and more particularly to a distributed constant type LC noise filter in which a LC distributed constant circuit including an inductor conductor and a capacitor conductor is formed in a laminated structure in which a plurality of insulating layers are laminated.

[0002]

2. Description of the Related Art With the development of electronic technology in recent years, electronic circuits have been widely used in various fields. Therefore, these electronic circuits can be operated stably and reliably without being affected by external noise. It is desired to make it.

In particular, in recent years, various types of high-performance electronic devices have been used in many cases, and accordingly, regulations on noise have become increasingly intense. Therefore, it is desired to develop a small and high-performance noise filter capable of reliably removing generated noise.

However, in a conventional LC noise filter, two sets of windings 12 and 14 are wound around a core 10 as shown in FIG.
18 were connected in parallel.

Therefore, the size of the core 10 and the windings 12 and 14 constituting the inductor becomes large, and the inductor and the capacitors 16 and 18 are formed as separate members. There is a problem that the required quality of weight reduction cannot be satisfied.

To solve such a problem, Japanese Unexamined Patent Publication No.
56-50507, JP-A-56-144524, JP-A-56-142622,
A proposal according to JP-A-63-76313 has been made.

In this prior art, for example, in a composite electronic component according to Japanese Patent Application Laid-Open No. 56-50507, as shown in FIG. 22, a laminate is formed by laminating a plurality of insulator layers 20a, 20b, 20c. Then, each of the insulator layers 20a, 2
0b ..., conductive patterns 22a, 22b, 22c continuously circulating from one layer to the next layer are provided.
Thus, a coil L having a predetermined number of turns is formed.

The insulator layers 20a, 20b, 20
The conductive layers 24a and 24b are arranged between the layers c and c at intervals from the circumferential conductive patterns 22a and 22c, and a capacitance C is formed between the conductive layers 24a and 24b and the conductive patterns 22a and 22c.

As a result, as shown in FIG.
And a lumped-constant noise filter composed of

Further, according to this prior art, since L and C are incorporated in the laminated body, it can be used as a small and lightweight LC noise filter.

[0011]

However, this LC
The filter is a part 22 of the conductive pattern forming the coil.
Only the conductive layers 24a and 24c that form the capacitance are provided adjacent to the straight line portions of a and 22c. For this reason, there is a problem that the capacitance C between the coil and the conductive layer 24 is small, and good attenuation characteristics cannot be obtained.

In particular, this LC filter is formed as a lumped constant type LC filter as shown in FIG.
For this reason, there has been a problem that various types of noise, particularly common mode noise such as switching surge, and normal mode noise such as ripple cannot be reliably removed.

Further, there is a problem that this LC filter can be used only as a three-terminal type normal mode filter and cannot be used as a four-terminal type common mode noise.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a small-sized LC noise filter capable of reliably removing intruding noise.

Another object of the present invention is to provide an LC noise filter which can be used not only as a normal mode noise filter but also as a common mode noise filter as required.

[0016]

In order to achieve the above object, an LC noise filter according to the present invention comprises a laminated body in which a plurality of insulating layers are laminated, a layer between the insulating layers, and one layer to another layer. A first conductive element that continuously circulates between the first conductor and the first conductor that forms a coil having a predetermined number of turns, and a first conductor that continuously circulates from one layer to another between the insulating layers. And a second conductor having two conductive elements, wherein the first and second conductive elements are each formed in a thin plate or film shape, provided between the layers, and provided with an insulating layer interposed therebetween. And forming a facing capacitance.

[0017]

Next, the operation of the present invention will be described.

In the LC element of the present invention, a plurality of insulating layers are laminated to form a laminate.

The first conductor is provided so that the first conductive element continuously circulates between the insulating layers from one layer to another. Thereby, the first conductor functions as a coil having a predetermined inductance.

The second conductor is provided such that the second conductive element continuously circulates from one layer to another between the insulator layers.

A feature of the present invention is that the first conductive element is provided so as to face the second conductive element via an insulating layer, and a capacitance is formed between the two. It is in.

At this time, it is presumed that the second conductor forms a capacitance between the first conductor and the first conductor in a distributed constant manner. Therefore, the LC noise filter of the present invention functions as a distributed constant type LC filter, can obtain better attenuation characteristics over a relatively wide band, and can ring various noises as compared with the conventional lumped constant type LC filter. It can be removed without accompanying. In particular, the LC noise filter of the present invention uses the L of the distributed constant circuit.
The component and the C component function effectively, and various noises can be effectively removed.

Furthermore, the LC noise filter of the present invention
By providing a ground terminal on the second conductor and providing input / output terminals at both ends of the first conductor, it can be used as a normal mode type LC noise filter.

Further, the LC noise filter according to the present invention comprises:
By providing input / output terminals at both ends of the first and second conductors, it can be used as a common mode type LC noise filter.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the present invention will be described in detail with reference to the drawings.

First Embodiment FIGS. 1 to 3 show a preferred example of the present invention.

The LC noise filter according to the embodiment includes a laminated body 30 formed by laminating a plurality of insulating plates 32-1, 32-2,..., 32-4, and interlayers 36-2, 36 of the insulating plate 32.
-3, 36-4, a first conductor 40 forming a coil of a predetermined number of turns, and an interlayer 36 of the insulating plate 32.
1, 36-2, 36-3, a second conductor 5 provided opposite to the first conductor 40 via an insulating plate 32.
0.

The insulating plates 32 may be formed using various insulating materials as needed. As the insulating material, for example, ceramics, plastics, various synthetic resins, and the like can be considered. In the embodiment, the insulating material is formed using ceramics.

In the laminated body 30 of the embodiment, in order to prevent the first conductor 40 and the second conductor 50 from being short-circuited, each of the insulating plates 30 is made of an interlayer insulating sheet 34-1, 34-2, 34-.
3 are laminated.

The first conductor 40 is provided on the surfaces of the uppermost insulating plate 32-1 and the lowermost insulating sheet 34-3.
Terminals 42a and 42b and a terminal 52 of the second conductor 50.
a and 52b are formed by coating.

The first conductor 40 and the second conductor 50 are formed between the interlayers 36-1, 36-2,... Of the insulating plate 32.
36-4, a plurality of first conductive elements 44-1 and 44- continuously circulating from one layer to another layer.
2, 44-3 and the second conductive element 54-1,
54-2 and 54-3.

Here, the characteristic feature is that the first and second conductive elements 44 and 54 are
, And a capacitance is formed almost continuously between the two.

As a result, the first and second conductors 40,
The reference numeral 50 functions as a coil having a predetermined number of turns, and a capacitance C is substantially continuously formed between the first and second conductors 40 and 50 via an insulating plate 32. 1st and 2nd
Is assumed to be formed between the conductors 40 and 50 in a distributed constant manner.

Here, the first and second conductive elements 44 and 54 of the embodiment are formed by coating on both surfaces of the insulating plate 32 so as to face each other by using a technique such as printing, vapor deposition or plating. I have. Conductive pattern 4 for connection
6 and 56 are also coated on the insulating plate 32.

The terminal 52a formed on the surface of the insulating plate 32-1 is connected to the insulating plate 32 through the through hole 33.
-2 is connected to the second conductive element 54-1 provided on the second conductive element 54-1. Similarly, the terminal 52b coated on the lowermost insulating sheet 34-3 is also connected to the second conductive element 54 through the through holes 35 and 33 provided in the insulating sheet 34-3 and the insulating plate 34-4. -3.

Similarly, one input terminal 42-b provided on the surface of the insulating plate 32-1 is connected to each of the insulating plates 32-1 and 32-2.
2 is connected to the end of the first conductive element 44-1 provided on the back surface side of the insulating plate 32-2 through the through hole 33 and the conductive pattern 46 provided on the insulating plate 32-2.
Similarly, the other input / output terminal 42 a provided on the lowermost interlayer insulating sheet 34-3 is
It is connected to a first conductive element 44-3 coated on the insulating plate 32-4.

Each of the insulating plates 32-2, 32-3, 32
-4, the first conductive element 44 and the second conductive element 54 formed on the insulating plate 3
2, through hole 33 formed on conductive pattern 4
6, 56 and a through hole 35 provided on the interlayer insulating sheet 34, from one interlayer 36 to another interlayer 3.
6 and electrically connected.

Thus, in the LC noise filter of the embodiment, both ends of the first conductor 40 are connected to the terminals 42.
a, 42b to function as a coil having a predetermined inductance L1. Similarly, the second conductor 50 has both ends connected to the terminals 52a and 52b, and functions as a coil having a predetermined inductance L2.

Further, as described above, it is presumed that the capacitance C is formed between the first and second conductors 40 and 50 almost continuously and as a distributed constant.

Therefore, the LC noise filter of the present invention is
Excellent characteristics that cannot be exhibited by the conventional lumped-constant LC element can be exhibited. By using this LC noise filter as an LC noise filter, excellent attenuation characteristics can be exhibited over a wide band.

In addition, according to the present invention, the first and second conductors 40 and 50 are opposed to each other via the insulating plate 32. Therefore, compared to the conventional LC noise filter,
It can be understood that a sufficiently large capacitance C can be obtained, and from this aspect, it can be used as an LC noise filter having better attenuation characteristics than the conventional LC noise filter.

Further, the conductive element 44,
Numerals 54 are three-dimensionally arranged, for example, as shown in FIG. At this time, for example, the first conductive element 44-1
As an example, the conductive element 44-1 not only forms a capacitance in opposition to the second conductive element 54-1 through the insulating plate 32-2, but also forms a capacitance below the second conductive element 54-1. The capacitance is formed between the second conductive element 54-3 and the second conductive element 54-3. As described above, since each conductive element 44 forms a capacitance with the second conductive element 54 located on the upper and lower sides thereof, a sufficiently large space is provided between the two in a limited space. It will be understood that a capacitance C can be obtained, resulting in an LC noise filter having better characteristics.

In order to further increase the capacitance C of the LC element, it is preferable to provide irregularities on the surface of the insulating plate 32 by edging or the like as shown in FIG. By covering the surface of the insulating plate 32 thus formed with the conductive elements 44 and 52, the conductive elements 44 and 54 are opposed to each other in a wide area. As a result, a larger capacitance C can be obtained even with LC elements having the same size.

As described above, according to the present invention, it is possible to obtain an LC device in which the capacitance C is formed with a distributed constant, and without increasing the size of the device itself.
The capacitance C can be set to a large value as required, and it is possible to exhibit excellent characteristics not available in the conventional LC noise filter.

In particular, when the present invention is applied to a noise filter, it exhibits excellent attenuation characteristics over a wide band,
An excellent noise removing effect can be obtained as compared with the conventional lumped constant type LC element.

Further, the LC noise filter of this embodiment is
It can be used as both a normal mode LC noise filter and a common mode LC noise filter.

That is, in the LC noise filter of this embodiment, as shown in FIG. 3A, by grounding either of the terminals 52a and 52b, a normal mode type LC in which L and C are formed as distributed constants is provided. It can be used as a noise filter.

As shown in FIG. 3B, the terminals 52a and 52b connected to both ends of the second conductor 50 are not grounded but are used as input / output terminals, so that the LC
The noise filter can also be used as a four-terminal common mode LC noise filter in which capacitance is formed between both conductors in a distributed constant manner.

FIG. 2 shows an example in which the LC noise filter of this embodiment is formed as a three-terminal normal mode noise filter.

In this case, a laminate 30 is formed by laminating and fixing the insulating plate 32 and the interlayer insulating sheet 34 shown in FIG. After that, the input terminals 42a, 42a formed on the front and back sides of the laminate 30 are connected, and a conductive material is formed so as to cover and function as one terminal. Similarly, the input / output terminals 42b, 42b are coated with a conductive material so as to function as one terminal. In the same manner, the terminals 52a,
52b is also covered with a conductive material (in this embodiment, the end of the second conductor 50 and one terminal 52b are insulated so that only one end of the second conductor 50 is grounded. Then, at least one of the through holes 33 and 35 of the insulating plate 32-4 and the insulating sheet 34-3 shown in FIG. 1 is removed).

Thus, a three-terminal noise filter having two input / output terminals 42a and 42b and one ground terminal 52 provided on the outer peripheral surface of the laminate 30 is formed. In addition, since this noise filter is formed as an SMD type (surface mount device) element, its handling is extremely easy.

In the first embodiment, the case where the through-holes 33 and 35 are used for connection of each part of the circuit has been described as an example. However, the present invention is not limited to this. For example, as shown in FIG. 6, conductive caps 33a, 35a may be used in place of through holes 33, 35, and conductive plating, printing or coating of a conductive pattern, etc. May be used. Also, through holes 33, 3
5. The conductive caps 33a and 35a, conductive patterns such as plating, and the like may be used in any combination.

When the conductive caps 33a and 35a are used, the insulating plate 32 and the interlayer insulating sheet 34 are used.
It is preferable that the conductive patterns 46 and 56 be formed so as to cover the places where the conductive caps 33a and 35a are fitted to reduce the contact resistance.

Further, in the above embodiment, as shown in FIG. 2, the terminals 42a, 42b,
Although the case where the coating 52 is formed is described as an example, this terminal pattern can be arbitrarily formed as needed. For example, as shown in FIG. 7, the terminals 42a, 42b, and 52 may be formed on one end surface of the laminate 30 by coating. Also, as shown in FIG. 8, the input / output terminals 42a,
42b may be coated and the other end side may be coated with a ground terminal 52.

In the above embodiment, the case where the LC noise filter of the present invention is formed as an SMD type element has been described as an example. However, the present invention is not limited to this, and for example, as shown in FIG. The elements 42a, 42b and 52 may be formed as discrete elements having a pin structure. 4A to 4D show an example of a procedure for attaching the pin structure terminals 42a, 42b, and 52.

In the embodiment shown in FIG. 1, the first and second conductive elements 44,
54, the interlayer 36 of each insulating plate 32 is formed.
It was necessary to interpose an interlayer insulating sheet 34 between 2, 36-3,. However, by providing the first and second conductive elements 44 and 54 only on one side of each insulating plate 32, the interlayer insulating sheet 34 can be used without using the interlayer insulating sheet 34.
The laminate 30 can also be formed.

For example, as shown in FIG.
First conductive element 4 on 2, 32-4, 32-6
4-1, 44-2, 44-3 are formed by coating, and the insulating plate 32
-3, 32-5 on the surface of the second conductive element 54-
1, 54-2 is coated.

In this way, since the conductive elements 44 and 54 are completely insulated from each other via the insulating plate 32, the stacked body 30 can be formed without an insulating sheet or the like between them. Can be formed.

Particularly, in this case, the pattern of the first conductive elements 44 can be made the same shape, and the second conductive elements 54-1 and 54-2 can be made the same shape. For this reason, conductive elements 4 of the same shape
A large number of insulating plates 32 having coatings 4 and 54 formed thereon are prepared, and the direction of each of the insulating plates 32 is changed to be stacked.
An element can be formed. This makes it possible to increase the use of common parts and reduce costs.

In the embodiment shown in FIG. 10, the case where one of the first conductive element 44 and the second conductive element 54 is formed on the surface of one insulating plate 32 has been described as an example. Are provided on the same insulating plate 32 as shown in FIG. 11, for example.
4, 54 may be formed by coating.

In this case, these insulating plates 32-1 and 32-3
2-2 ... 32-5 are laminated and fixed, and the laminate 3 shown in FIG.
0 may be formed. Thereby, for example, the second conductive element 54-1 is connected to the insulating plate 32-2, the insulating plate 32-
3, the first conductive elements 44-1 and 44-3 face each other, and a capacitance is formed therebetween.

By forming as described above, FIG.
0, the interlayer insulating sheet 34 is unnecessary. Moreover, the conductive elements 4 having the same pattern
Since the laminated body 32 formed by coating the layers 4 and 54 can be used, it is possible to increase the commonality of parts and reduce the cost.

The conductive pattern of the present invention is not limited to those shown in FIGS. 1, 10 and 11, and may be, for example, the first and second conductors 40 and 5 in the laminate 30.
In order to increase the inductance and the capacitance of 0, as shown in FIG.
A first conductive element 44 is formed on one side of 32-3 and 32-4 by coating.
4 is a through hole formed in the insulating plate 32 (not shown)
Are electrically connected so as to continuously go from one layer to another layer.

At the same time, each of the insulating plates 32-1 and 32-
A second conductive element (not shown) facing the first conductive element 44 is formed on the back side of the second conductive element 2, 32-3, 32-4. Is electrically connected so as to continuously go around from one layer to another via a through hole (not shown).

As a result, the number of turns of the first and second conductors 40 and 50 formed in the laminate 30 is increased.
An LC noise filter having a large inductance L and a large capacitance C can be obtained.

At this time, the first and second conductors 4
The patterns 0 and 50 can be set arbitrarily. For example, patterns shown in FIGS. 14 and 15 can be adopted instead of the patterns shown in FIG.

In FIGS. 13 to 15, the conductive elements are electrically connected in the order of the numbers attached to the ends.

When ceramics is used as the insulating plate 32 as in this embodiment, the insulating plate 32 can be formed by firing a green sheet. That is, an unfired highly flexible thin plate containing a dielectric material, a sintering aid, a binder and the like (this is called a green sheet) is prepared. This green sheet is applied to the insulating plate 32
And an insulating sheet 34 are prepared. Then, for example, each conductive pattern as shown in FIG. 1 is printed on this green sheet, and further, through holes and the like are formed at necessary places. Then, the sheets are sequentially stacked in accordance with the stacking order of FIG. 1, and a plurality of sheets on which no internal electrodes are printed are stacked on both outer sides for insulation and reinforcement. This laminated sheet is integrally formed under a constant temperature, humidity and pressure, and the monolithic one is cut into raw chips. Further, the green chip is fired at a predetermined temperature, and a conductive pattern is applied to the outer surface of the fired chip where the terminals are exposed, as shown in FIG. 2, and baked at a high temperature. In this way, the LC noise filter of the present embodiment can be formed by using the manufacturing method of the multilayer ceramic chip capacitor.

Second Embodiment Next, a preferred second embodiment of the LC noise filter of the present invention will be described.

Although the LC noise filter of the above embodiment uses an insulating plate as an insulating layer, the present embodiment is characterized in that an insulating thin film or an insulating thick film is used as an insulating layer.

Thus, it is possible to form an LC noise filter by using the film forming technique.

FIG. 16 shows a preferred example of a manufacturing process of this LC noise filter using a thin film forming technique.

In the LC element of this embodiment, as shown in FIG. 16A, the auxiliary terminal 42a 'is formed on the insulating substrate 100 from the back surface to the side surface.
Of the first terminal continuous from the auxiliary terminal portion 42a '.
Of the conductive element 44-1 is coated in a substantially L-shape.

Next, as shown in FIG. 16B, an insulating thin film 200-1 is formed on the surface of the insulating substrate 100 so that the end of the first conductive element 44 is exposed.

Next, as shown in FIG. 16C, the first conductive element 44-2 electrically connected to the first conductive element 44-1 is coated. At the same time, the auxiliary terminal portion 52a 'is formed so as to cover from the back side to the side surface of the insulating substrate 100, and the insulating thin film 20 is formed.
0-1 on the first conductive element 4 which is continuous from the auxiliary terminal portion 52a 'and further through the insulating thin film 200-1.
The second conductive element 54-1 facing 4-1 is coated and formed in a substantially U-shape.

Next, as shown in FIG. 16D, an insulating thin film 200-2 is formed so as to cover the end of each of the conductive elements 44-2 and 54-1. Next, as shown in FIG. 16 (e), a first conductive film is formed on the insulating thin film 200-2 so as to face the conductive elements 54-1 and 44-2 via the insulating thin film 200-2. Element 44-
3. A second conductive element 54-2 is formed by coating.

The thin film forming step and the element forming step are repeated as shown in FIGS. 16F to 16L to form the laminate 30.

At this time, in the step of FIG.
An auxiliary terminal portion 42b 'continuous from the first conductive element 44-5 is formed on the side and back surfaces of the substrate 100.

Then, in the final step shown in FIG. 16 (m), the auxiliary terminal 4
The terminals 42a, 42b, 52 electrically connected to the terminals 2a ', 42b', 52a 'are coated.

Thus, according to the present embodiment, according to FIG.
It is possible to obtain a three-terminal LC element having a distributed constant type equivalent circuit composed of L and C as shown in FIG. Therefore, by using the LC element of this embodiment as, for example, a noise filter, it is possible to exhibit good attenuation characteristics over a wide band.

In this embodiment, the terminal 52a is provided only at one end of the second conductor 50 and is used as a ground terminal. However, the present invention is not limited to this, and the present invention is not limited to this. Terminals are provided at both ends of the 50, and a 4-terminal L
It may be formed as a C element. In this case, the terminals of the first and second conductors 40 and 50 are used as input / output terminals, respectively, and used as a common mode type LC noise filter having a capacitance formed between the conductors in a distributed constant manner. be able to.

The first and second conductors 40, 5
The pattern of 0 and the pattern of the insulating thin film 200 are not limited thereto, and may be formed as, for example, a pattern as shown in FIG. FIGS. 7A to 7M sequentially show the manufacturing steps of the LC element in this case.

Note that the LC noise filter of this embodiment is
It can be easily formed using various thin film forming techniques, for example, a vapor deposition method, a sputtering method, an ion plating method, a vapor phase growth method and the like.

For example, when the LC noise filter of this embodiment is formed by sputtering, a plurality of vacuum chambers separated by gates are prepared, and argon gas is sealed in each vacuum chamber. Then, the insulating thin film 200, the conductive element 44,
A target formed using a base material corresponding to the 54 material is provided. Each target is located in each of the chambers so as to face the substrate 100.
A mask for specifying a pattern is provided between the target and the substrate 100.

A negative DC voltage is applied to the target via a negative electrode, and a ground electrode is connected to the substrate 100. Then, by applying a high-frequency voltage between the negative electrode and the ground electrode, the target receives the impact of positively ionized gas and emits its atoms or molecules, which are sputtered toward the substrate 100 to form a thin film. Adhere to the shape. The sputter pattern at this time is determined by the mask pattern.

Therefore, a vacuum chamber corresponding to the thin film forming step of forming the insulating thin film 200 on the substrate 100 and a chamber for the element forming step of forming the conductive elements 44 and 54 are provided. By repeating the process and the element forming process alternately, the LC noise filter of the embodiment can be easily formed.

The LC noise filter of the present invention formed by such a thin film forming technique can be smaller and lighter than that of the first embodiment.

Third Embodiment FIGS. 18 and 19 show a preferred third embodiment of the present invention.

The feature of this embodiment is that the first and second conductors 40 and 40 are provided between the layers of the insulating thin film 200 similarly to the above embodiments.
In addition to forming and covering the third conductor 60, the third conductor 60 facing the second conductor 50 with the insulating thin film 200 interposed therebetween is formed.

As a result, as shown in FIG.
The third conductors 40 and 50 function as coils having predetermined inductances L1 and L3. Furthermore, the first
A capacitance C1 is formed between the second and third conductors 40 and 50 in a distributed manner.
A capacitance C3 is formed between 0 and 60 in a distributed constant manner.

Accordingly, the terminal 52a of the second conductor 50 is grounded, and the terminals 42a and 42a of the first and third conductors 40 and 60 are grounded.
By using 42b, 62a, and 62b as input / output terminals, it can be used as a common mode type LC noise filter.

FIG. 18 shows such a common mode type L
An example of the manufacturing process of the C noise filter is shown in order.

First, as shown in FIG.
Of the auxiliary terminal portions 42a ', 62
a 'and a first conductive element 44-1 and a third conductive element 64-1 are formed on the surface of the substrate 100.

Next, as shown in FIG. 18B, the insulating thin film 20 is formed on the surface of the substrate 100 so that the ends of the first and second conductive elements 44-1 and 64-1 are exposed.
0-1 is coated.

Next, as shown in FIG.
The auxiliary terminal portion 52a 'is formed so as to cover from the back surface side to the side surface of the substrate 100, and the second conductive element 54- is formed on the surface of the substrate 100 so as to be continuous with the auxiliary terminal portion 52a'.
1 is coated. This second conductive element 54-
1 is opposed to the first conductive element 44-1 via the insulating thin film 200-1.

Next, as shown in FIG. 18D, the insulating thin film 200-2 is coated on the surface of the substrate 100 so as to expose the ends of the conductive elements 44-1, 54-1 and 64-1. Then, as shown in FIG.
Second and third conductive elements 44-2, 54-
2, 64-2. At this time, the second conductive element 54-2 includes the insulating thin films 200-2 and 200-.
2, the first conductive element 44-1 is formed so as to be opposed to the first conductive element 44-1.
The second conductive element 54 via the insulating thin film 200-2
A coating is formed so as to face -1.

Next, as shown in FIG. 18 (f), an insulating thin film 200-3 is formed so as to cover the end of each of the conductive elements 44-2, 54-2 and 64-2. From FIG. 18 (g), each conductive element 44-
3, 54-3 and 64-3 are formed by coating. At this time, the first conductive element 44-3 is an insulating thin film 200-3.
The second conductive element 54-3 is formed so as to face the third conductive element 64-2 via the insulating thin film 200-3.
The third conductive element 64-3 is formed so as to face the second conductive element 54-2 via the insulating thin film 200-3.

Then, as shown in FIG. 18F, an insulating thin film 200-4 is formed on the substrate 100 so as to expose the ends of the conductive elements 44-3, 54-3 and 64-3. .

Such a thin film forming step and an element forming step are repeated as shown in FIGS. 18 (i) to 18 (o), and finally, as shown in FIG.
An insulating thin film 200-8 is formed so as to cover the entire upper surface of No. 4.

In each of the steps (k) and (o) in FIG.
The conductive element 4 extends from the side to the back of the substrate 100.
4-7, terminal auxiliary part 42 connected to the end of 64-7
b 'and 62b' are formed by coating.

Then, in the step shown in FIG. 18 (p), the terminal auxiliary portions 42a ', 42b', 52
The conductive caps are fitted and fixed to the locations covered by a ', 52b', 62a ', and 62b'. As a result, FIG.
8 (q), the terminals 42a, 42 of the first conductor 40
2b, the terminal 52a of the second conductor 50, and the terminals 62a and 62b of the third conductor 60 are formed. In place of the conductive cap, a predetermined conductive pattern may be formed by, for example, plating, printing, baking, or the like, or may be used in combination with these conductive caps.

Therefore, as shown in FIG. 19, the terminal 52a of the second conductor 50 is grounded, and the first and third conductors 4
By using the 0, 60 terminals 42a, 42b, 62a, 62b as input / output terminals, it is possible to use as a common mode type LC filter in which the capacitance C is formed between the conductors 40, 50 and 60 in a distributed constant manner. it can.

The pattern of the insulating thin film 200 formed on the substrate 100 and the patterns of the conductive elements 44 and 54 can be arbitrarily set as required.

Further, in this embodiment, an example in which an LC filter of the type shown in FIG. 19 is formed by using a thin film forming technique has been described. However, the present invention is not limited to this. As shown, instead of the insulating thin film 200, an insulating plate 3 is used.
It is also possible to form using 0.

In this embodiment, the five-terminal type LC element shown in FIG. 19 has been described as an example. However, when it is desired to increase the current capacity, the first and third conductors 40 and
60 can be used in parallel connection. Also,
For example, by connecting the first and third conductors 40 and 60 in series, the first and third conductors 40 and 60 can also be used as an LC element having a larger inductance than the capacitance.

Fourth Embodiment In each of the above embodiments, the first, second and third conductors 4
0, 50, 60 conductive elements 44, 54, 64
However, the present invention is not limited to this, and it is possible to form the LC element by changing the coil diameter as necessary.

FIG. 20 shows an example of the LC element formed in this manner. The LC element of the embodiment has first and second LC elements.
Of the conductors 40, 50 of the insulating thin films 200-1, 200-
2,200-3... 200-6 interlayer insulating thin films 2
In this case, a three-terminal normal mode type LC filter is formed so as to face each other through the intermediary layer 00.

In the present embodiment, the first and second conductors 40 and 50 have their conductive elements 44 and 54
However, the coil continuously circulates from one insulating layer to the next while gradually decreasing the coil diameter.

As a result, the resonance characteristics of the LC element of the embodiment can be different from those of the above-described embodiments. In addition, the attenuation characteristics are slightly different from those of the above embodiments, but are excellent over a wide band.

Further, contrary to the embodiment, by forming the first and second conductors 40 and 50 so that the coil diameter gradually increases, the inductance L of each conductor gradually increases. Thereby, it can be used as a noise filter capable of removing noise while effectively suppressing ringing.

In this embodiment, the first and second conductors 4
Although the case where the 0, 50 and the insulating thin film 200 are formed by using the thin film forming technique has been described as an example, the present invention is not limited to this. It can be applied to the case where is used.

In this embodiment, the first and second conductors 4
Although the LC element is configured using 0, 50, it is needless to say that the present invention can be applied to an LC element configured using the first, second, and third conductors 40, 50, 60 as necessary. No.

In this embodiment, the first and second conductors 4
The case where the resonance point of the LC element is shifted by changing the coil diameter of 0, 50 has been described as an example. However, the present invention is not limited to this. For example, the first and second conductive elements 44, 54 may be used as necessary. The resonance point can also be shifted by changing the facing width (area).

Fifth Embodiment FIG. 24 shows a fifth preferred embodiment of the present invention. Members corresponding to those of the above-described embodiments are denoted by the same reference numerals, and description thereof is omitted.

The LC element of this embodiment is formed as a normal mode LC noise filter as shown in FIG.

The feature of this embodiment is that the second conductor 50 functioning as a capacitor conductor is divided into a plurality of parts, and each divided section is grounded to form divided ground conductors 50-1, 50-2, and 50-3. It is in. Each of these divided ground conductors 50-1, 5
One end of each of O-2 and 50-3 is connected to the ground terminal 52a.

The thus formed LC noise filter is provided with the divided ground conductors 50-1, 50-2, and 50.
Since the self-inductance L of −3 is small, the capacitance formed as a distributed constant with the first conductor 40 can be used as it is as the capacitance of the LC filter.

The present inventor further studied and found that
It has been found that the position of the ground conductors 50-1, 50-2, 50-3 facing the first conductor 50 functioning as an inductor has a great influence on the attenuation characteristics of the noise filter. Then, as in the embodiment, the divided ground conductors 50-1 and 50-3 located at both ends are connected to the first conductor 4
It has been confirmed that excellent attenuation characteristics can be obtained by arranging the input / output terminal close to the input / output terminal 0 in terms of electric circuit.

Each of the divided ground conductors 50-1 and 50-
A study was made on how to set the grounding position of 2,50-3. As a result, the divided ground conductor 50-1 located at a location closer to the one input / output terminal 42a in terms of an electric circuit is
It is preferable that the input / output terminal 42a is grounded at a position close to the electric circuit.
It has been confirmed that it is preferable that each of 0-3 is grounded at a position closer to the other input / output terminal 46b in terms of an electric circuit.

By doing so, L of this embodiment is
The C noise filter functions as a normal mode filter having good attenuation characteristics.

As shown in FIG. 24B, the first and third conductors 40 and 60 function as inductor conductors, and the second conductor 50 functions as a capacitor conductor.
In the case of the C element, the second conductor 50 is divided and grounded in the same manner, so that it functions as a filter having good attenuation characteristics.

Other Embodiments The present invention is not limited to the above-described embodiment.
Various modifications can be made within the scope of the present invention.

For example, in each of the above embodiments, the first, second,
Although the third conductors 40, 50, and 60 have been described as being formed on the insulating plate 30 and the substrate 100, for example, or formed on the insulating thin film 200, the present invention is not limited to this. For example, a conductive plate is punched and formed into the shape of the first, second, and third conductive elements 44, 54, and 64,
This may be mounted and fixed on the insulating plate 30 already sintered, the substrate 100, and the insulating thin film 200.

Next, the process of using barium titanate (BaTiO ₃ ) as the insulating plate 30 and attaching and laminating a copper plate formed by punching to form a conductive element on the insulating plate 30 will be briefly described. .

In this case, first, barium titanate in the form of a rectangular thin plate is placed in an air atmosphere at 1250 ° C. to 13 ° C.
The insulating plate 30 is formed by firing at a temperature of 50 ° C. for about 2 hours.

Next, the insulating plate 30 and a copper plate stamped and formed in a predetermined conductive pattern are laminated, for example, as shown in FIG. 10, and the laminated body is sandwiched from both sides by a predetermined pressure. . Then, the laminate is fired in a predetermined neutral atmosphere (reducing atmosphere) at a temperature equal to or lower than the melting point of copper and equal to or lower than 1100 ° C.

In this case, the neutral atmosphere is
It is preferable to set an atmosphere in which nitrogen is doped with 2 to 100 ppm of oxygen. The reason for setting the temperature to 1100 ° C. or lower is that if barium titanate is fired at a temperature of 1100 ° C. or higher, the barium titanate becomes a semiconductor due to a reaction. 9 in the embodiment
The laminate is fired at a temperature of 50 to 1000 ° C. for a predetermined time.

At this time, a low melting point compound such as pyrochlore is formed between the insulating plate 30 made of barium titanate and the copper plate, whereby the copper plate and the insulating plate 30 are bonded well. Will be.

The reaction at this time is improved as the amount of oxygen doped in the neutral atmosphere is increased. However, when the amount of oxygen is increased, the surface of the copper plate functioning as a terminal is also oxidized, so that the riding of the solder is deteriorated. . For this reason, it is preferable that the LC element fired in a neutral atmosphere having a large oxygen doping amount be fired once more in a predetermined reducing atmosphere.

Thus, even when barium titanate is used as the insulating plate 30 and copper plates are punched out as the conductive elements 44, 54, 64, an LC noise filter can be formed satisfactorily. be able to.

It is to be noted that a thermoplastic plastic can be used instead of barium titanate, but in this case, it is presumed that the secular change is large and the durability is inferior to barium titanate.

In each of the above embodiments, the insulating thin film 200 was used.
Has been described by taking as an example the case of forming by a thin film forming technique, but the present invention is not limited to this, and may be formed by other methods as needed, for example, using an insulating sheet or the like.

In each of the above embodiments, when increasing the inductance of the first, second and third conductors 40, 50 and 60, for example, the insulating layer (the insulating plate 30 or the insulating thin film 2) may be used.
00), the number of turns of each of the conductors 40, 50, and 60 is set to be large, and the patterns shown in FIGS. 14 and 15 are used as examples. However, the present invention is not limited to this,
Other than this, for example, each of the conductive elements 44, 54,
The conductive material 64 may be formed by using a conductive magnetic material such as Fe, for example, or a magnetic material may be bonded or powder-coated on each of the conductive elements 44, 54 and 64. Further, by using a technique such as mixing a magnetic substance in the insulating plate 32 and the insulating thin film 200, the inductance L thereof can be increased.

In addition, as shown in FIGS. 7 and 8, for example, a magnetic core insertion hole 70 is provided at the center of the laminate 30.
The surface of the laminate 30 may be powder-coated with a magnetic material or housed in a magnetic container to form an open magnetic path or a closed magnetic path passing around the laminate 30 through the insertion hole 70.

If necessary, the lengths of the first, second and third conductors 40, 50 and 60 are set to different values. For example, the first conductor 40 is formed longer than the second conductor 50. However, the inductance L can be set large.

In each of the above embodiments, the first and second
In order to increase the value of the capacitance formed as a distributed constant between the third conductors 40, 50, and 60, the width of each of the conductive elements 44, 54, and 64 is increased to increase the facing area thereof. Just do it.

In addition, the capacitance may be increased by using a high dielectric constant as the insulating plate 32 and the insulating thin film 200 used as the insulating layer, or by increasing the number of stacked insulating layers. Can be increased.

In addition, the capacitance can be increased by, for example, reducing the thickness of each of the above-mentioned insulating layers, or by adopting an electrolytic capacitor system and making the conductor porous.

In the LC device of the present invention, for example, the second
When the conductor 50 is grounded and used as a normal mode filter, the width of the second conductor 50 is smaller than the width of each of the conductive elements 44 and 64 of the first conductor 40 and the third conductor 60.
By forming the width of the conductive element 54 of the first embodiment to be large, the second conductive element 54
Function as a shield for the conductive elements 44 and 64, and can effectively prevent leakage of magnetic flux between the layers and occurrence of a short circuit phenomenon.

Further, in each of the above embodiments, the case where the insulating plate 32 and the insulating thin film 200 used as the insulating layer are formed using an insulating material such as ceramics or plastic has been described as an example. By using an electromagnetic wave absorbing and heating element as an insulating material, the performance in a high frequency band as a noise filter can be improved.

In each of the above embodiments, the case where the LC noise filter of the present invention is used as a filter, particularly as a noise filter, has been described as an example. However, the present invention is not limited to this, and other applications, such as various It can be used both as a filter and as a varistor.

In each of the above embodiments, the case where the conductors face each other via the insulating layer has been described as an example. However, even if these conductors do not completely face each other, the capacitance is distributed between them. If they are formed in a constant manner, there may be a deviation between the two opposing positions.

In each of the above embodiments, the case where the thin film forming technique is used has been described as an example. However, the LC element of the present invention may be formed by using the thick film forming technique as required.

[0144]

As described above, according to the present invention,
A laminated body is formed by laminating a plurality of insulating layers, and the first conductor is continuously circulated from one layer to another layer between the insulating layers to function as a coil having a predetermined number of turns. In addition, a new configuration is adopted in which the second conductor continuously circulates from one layer to another layer between layers of the insulating layer so that the second conductor faces the first conductor via the insulating layer. By doing so, it is possible to form a sufficiently large capacitance between the first and second conductors facing each other via the insulating layer, and to obtain a compact, good-performance, and inexpensive LC noise filter. it can.

In particular, according to the present invention, it is presumed that the capacitance is formed in a distributed constant manner between the first and second conductors via the insulating layer. In comparison with the above, it can be used as an LC noise filter having excellent attenuation characteristics capable of reliably attenuating and removing various intruding noises.

Further, according to the present invention, by using both the first and second conductors as current-carrying conductors, they can be used as a common mode noise filter.
Further, by grounding the second conductor, there is also an effect that the second conductor can be used as a normal mode noise filter.

Further, as described in claim 2, by using the third conductor, the second conductor is grounded, and the first and third conductors are used as current-carrying conductors. It can be used as a type common mode noise filter.

According to the sixteenth aspect of the present invention,
An insulating layer and a conductor can be formed on the substrate by a film forming technique. Therefore, for example, by combining the present invention with a semiconductor manufacturing technique, an LC noise filter can be formed at the same time when an IC is formed on a wafer,
As a result, there is also an effect that the LC noise filter of the present invention can be incorporated in various ICs, for example, as an LC filter or the like to form an IC with a built-in LC filter.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a preferred embodiment of an LC noise filter according to the present invention.

FIG. 2 is an explanatory perspective view showing a state where the LC noise filter shown in FIG. 1 is assembled.

FIGS. 3A and 3B are equivalent circuit diagrams of an LC element according to an example.

FIG. 4 is an explanatory diagram of a three-dimensional arrangement of each conductive element.

FIG. 5 is an explanatory diagram of a case where an effective covering area of a conductive element is increased by forming irregularities on a substrate surface and forming a conductive element coating thereon.

FIG. 6 is an exploded perspective view of a modification of the embodiment shown in FIG. 1;

FIG. 7 is an explanatory diagram showing a modified example of the position of a terminal provided in an SMD type LC noise filter.

FIG. 8 is an explanatory diagram showing a modified example of the position of a terminal provided in an SMD type LC noise filter.

FIGS. 9A to 9D are explanatory diagrams illustrating an example of an LC noise filter formed in a discrete type.

FIG. 10 is an exploded perspective view showing an example of an LC noise filter formed by forming one type of conductive element on one insulating plate.

FIG. 11 is an exploded perspective view showing an example of an LC noise filter formed by coating two types of conductive elements on the same surface of one insulating plate.

FIG. 12 is a perspective explanatory view showing an example of an assembled state of the LC noise filter shown in FIG. 11;

FIG. 13 is an explanatory diagram of an LC noise filter formed by laminating a plurality of insulating plates on which patterns of a plurality of conductive elements are formed.

FIG. 14 is an explanatory diagram of an LC noise filter formed by laminating a plurality of insulating plates on which patterns of a plurality of conductive elements are formed.

FIG. 15 is an explanatory diagram of an LC noise filter formed by laminating a plurality of insulating plates on which patterns of a plurality of conductive elements are formed.

FIGS. 16 (a) to (m) are explanatory views showing a manufacturing process of an LC noise filter formed by coating a conductive element and an insulating thin film on a substrate by using a thin film forming technique.

FIGS. 17 (a) to (m) are explanatory diagrams of modified examples of the LC noise filter shown in FIG. 16;

FIGS. 18A to 18Q are explanatory diagrams illustrating an example of a manufacturing process of an LC noise filter formed using first, second, and third conductors.

19 is an equivalent circuit diagram of the LC element shown in FIG.

FIG. 20 is an explanatory diagram illustrating an example of a manufacturing process of an LC noise filter formed so that the coil diameters of the first and second conductors change.

FIG. 21 is an explanatory diagram showing an example of a conventional general LC noise filter.

FIGS. 22A to 22F are explanatory views showing an example of a manufacturing process of a conventional LC noise filter.

23 is an equivalent circuit diagram of the LC element shown in FIG.

FIGS. 24A and 24B are equivalent circuit diagrams of a fourth preferred embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 30 laminated body 32 insulating plate 34 interlayer insulating sheet 36 interlayer 40 first conductor 42 input / output terminal 44 first conductive element 50 second conductor 52 ground terminal 54 second conductive element 60 third conductor 62 input Output terminal 64 Third conductive element 70 Magnetic core insertion hole 100 Substrate 200 Insulating thin film

Claims (16)

(57) [Claims] 1. A laminate in which a plurality of insulating layers are stacked, and a first conductive element that continuously circulates from one layer to another layer between layers of the insulating layer is provided. A first conductor that forms a coil; and a second conductor having a second conductive element that continuously circulates from one layer to another layer between the insulating layers. And an LC noise filter, wherein the second conductive element is formed in a thin plate or film shape and provided between the layers, and faces each other via an insulating layer to form a capacitance. 2. The first conductor according to claim 1, wherein the second conductor is formed as a capacitor conductor having a ground terminal, and the first conductor is formed as an inductor conductor having input / output terminals at both ends thereof. An LC noise filter characterized by being used as a normal mode type LC noise filter. 3. The method according to claim 1, wherein the first and second conductors are formed as inductor conductors having input / output terminals provided at both ends thereof, and are used as a common mode type LC noise filter. LC noise filter. 4. The third conductive layer according to claim 1, wherein the third conductive layer continuously circulates from one layer to another layer between the insulating layers, and faces the second conductive element via an insulating layer. Provide a conductive element of
A third element for forming a capacitance between the third conductor and the second conductor;
Wherein the second conductor is formed as a capacitor conductor provided with a ground terminal, and the first and third conductors are formed as inductor conductors provided with input / output terminals at both ends thereof. An LC noise filter characterized by the above-mentioned. 5. The LC noise filter according to claim 1, wherein the laminated body is formed by laminating a plurality of insulating plates as insulating layers. 6. The insulating plate according to claim 5, wherein a first conductive element and a second conductive element are provided on both surfaces of the insulating plate so as to face each other. LC noise filter characterized by being laminated. 7. The laminate according to claim 1, wherein the laminate has a first insulating plate having a first conductive element provided on a surface thereof, and a second conductive element provided on a surface thereof. And a second insulating plate, wherein the first and second insulators are alternately stacked such that the first and second conductive elements face each other. LC noise filter. 8. The conductive element according to claim 1, wherein the first and second conductive elements provided between the insulating layers include first and second conductive elements provided between the other layers. An LC noise filter, which is electrically connected to an element via a conductive cap, a conductive plating layer, or a through hole formed in an insulating layer. 9. The device according to claim 1, wherein the first, second, and third conductive elements provided between the layers of the insulating layer include first, second, and third conductive elements provided between the other layers.
And a third conductive element, a conductive cap,
An LC noise filter electrically connected through a conductive plated layer or a through hole formed in an insulating layer. 10. The laminate according to claim 1, wherein the laminated body is formed by laminating an insulating film provided with an interlayer element exposed portion as an insulating layer, wherein the first and second conductive elements are An LC noise filter connected to the first and second conductive elements between the next layers via an exposed portion. 11. The semiconductor device according to claim 1, wherein the insulating layer is continuous between other layers and between the insulating layers.
A third conductive element opposed to the second conductive element via an insulating layer, and a third conductor forming a capacitance between the third conductive element and the second conductor. An insulating film provided with a portion is laminated as an insulating layer, and the first, second, and third conductive elements are connected to the first, second, and third conductive layers between the next layers via the exposed portion. Connected to the element, the second conductor is formed as a capacitor conductor provided with a ground terminal, the first and third conductors are formed as inductor conductors provided with input / output terminals at both ends thereof, An LC noise filter used as a common mode type LC noise filter. 12. The method according to claim 1, wherein fine irregularities are formed on a surface of the insulating layer,
And an LC noise filter, wherein the second conductor is formed by coating the surface of an insulating layer provided with irregularities. 13. The light emitting device according to claim 1, wherein the second conductor is divided and grounded.
C noise filter. 14. The LC noise filter according to claim 1, wherein the first conductor is formed so as to go around while changing the coil diameter from one layer to another layer. . 15. An electronic apparatus using the LC noise filter according to claim 1. 16. A film laminating step of sequentially laminating a plurality of insulating film layers on a substrate, and a first interlayer connection is performed every time each of the insulating film layers is laminated.
At least one of the conductive element and the second conductive element is coated so as to continuously circulate from one layer to another layer, and the first conductor having a predetermined number of turns and the second conductor having a predetermined number of turns are covered. And an element forming step of forming the conductor is alternately repeated. In the element forming step, the first conductive element and the second conductive element are coated so as to face each other via an insulating film layer. A method for manufacturing an LC noise filter, comprising: