KR20050080797A - Multilayered lc filter array - Google Patents

Abstract

The present invention relates to a stacked LC filter array in which a plurality of filters are embedded in one package. The present invention is directed to a stacked LC filter array in which a plurality of input / output terminals are formed on one side, and the same number of input / output terminals are symmetrically formed on opposite sides thereof, and a ground terminal is formed on the side where no input / output terminals are formed. A first inductor unit formed by stacking one or more sheets having a predetermined conductive pattern forming at least one inductor electrically connected at both ends to the pair of input / output terminals facing each other; A second inductor unit formed by stacking one or more sheets having a predetermined conductive pattern forming at least one inductor electrically connected at both ends thereof to a pair of input / output terminals opposed to each other without an inductor formed in the first inductor unit; ; And at least one ground layer having a pattern electrically connected to the ground terminal, and an input / output terminal electrically connected to both ends of the inductor formed at the first inductor, respectively, the capacitance between the connected input / output terminal and the ground layer. A first capacitor layer having a capacitance pattern formed thereon and an input / output terminal electrically connected to both ends of the inductor formed in the second inductor portion, respectively, and having a capacitance pattern forming capacitance between the connected input / output terminal and the ground layer. And a capacitor portion having a second capacitor layer, wherein the capacitor portion is formed under the first inductor portion, and the second inductor portion is formed under the capacitor portion.

Description

Stacked LC Filter Array {MULTILAYERED LC FILTER ARRAY}

The present invention relates to a stacked LC filter array in which a plurality of filters are embedded in one package. More particularly, the present invention relates to a stacked LC filter array, and more particularly, to form a capacitive pattern in a symmetrical manner, and does not require distinction between an input terminal and an output terminal. The present invention relates to a stacked LC filter array, which can be easily adjusted and has excellent attenuation characteristics in a wide high frequency band.

Recent advances in digital, semiconductor, electronic, and computer technologies have made it possible to reduce the weight, size, speed, and bandwidth of electric and electronic devices, and to operate them even with small driving energy. It reacts sensitively to minute electromagnetic wave noise, which causes malfunction, and as many electric and electronic devices are spread in various fields of society, electromagnetic density increases and makes the electromagnetic environment worse. There are many problems such as confusion in society because it does not work as well as the possibility of human handicap. Accordingly, there is a demand for a high performance noise filter having an electromagnetic noise attenuation effect over a wide band of high frequency areas in accordance with the recent trend of signal high frequency.

In order to remove such high frequency noise, a stacked LC filter array in which a plurality of LC filters are packaged into one chip may be used. Conventionally, a stacked LC filter array in which a plurality of LC filters are arranged by using a stacked capacitor and a stacked inductor as shown in FIG. 1 is used. As shown in FIG. 1A, a conventional LC filter array has a plurality of inputs i1 to i4 on one side, a plurality of outputs o1 to o4 on the other side opposite thereto, and a plurality of grounds on the other two sides. It has a package form with stages (g1 to g2). The conventional LC filter array shown in FIG. 1 is an example in which four LC filters are arranged. In the conventional LC filter array, the input stages i1 to i4 and the output stages o1 to o4 should be distinguished, and thus a mark M for distinguishing the positions of the input stage and the output stage is provided on one side of the upper surface of the filter.

FIG. 1B is an equivalent circuit diagram of the conventional LC filter array shown in FIG. 1. In the conventional LC filter array, a plurality of inductors L1 to L4 connected at both sides to the input terminals i1 to i4 and one side to the input terminal are respectively connected. The other side is composed of a plurality of capacitors (C1 to C4) connected to the ground (g1, g2), respectively. The conventional LC filter array shown in FIG. 2 is an example in which four LC filters are arranged. As shown in FIG. 2, the conventional LC filter array has a circuit structure in which the input terminal and the output terminal are distinguished from each other because the connection structure of the inductor and the capacitor is not symmetrical.

FIG. 1C illustrates an internal pattern of the conventional LC filter array. A mark layer 10 is formed on the uppermost layer to indicate positions of an input terminal and an output terminal, and a coil shape is formed below the mark layer 10. A first inductor part 11a formed by stacking a plurality of sheets having a pattern formed thereon is formed, and a first ground layer 12a and a lower portion of the first ground layer 12a are disposed below the first inductor part 11a. The capacitor layer 13 having a plurality of rectangular patterns and the second ground layer 12b are sequentially formed under the capacitor layer 13, and form a coil shape under the second ground layer 12b. The second inductor part 11b formed by stacking a plurality of sheets on which a pattern is formed is formed again. Between the first inductor portion 11a of the mark layer 10, between the first inductor portion 11a and the first ground layer 12a, and the second inductor portion 11b and the second ground layer 12b. ), And a dummy layer 14 may be formed under the second inductor part 11b.

The first inductor part 11a and the second inductor part 11b each form two coils, one end of each coil being connected to an input terminal of the LC filter array together with one capacitor pattern formed in the capacitor layer 13. They are each connected, and the other end of each coil is connected to the output end of the LC filter array, respectively, to form a circuit as shown in FIG. 1B.

A plurality of capacitor patterns are formed in the capacitor layer 13 of the conventional stacked LC filter array as shown in FIG. 1C. The capacitor pattern is formed asymmetrically so as to be connected to the side where the input terminal is formed, as shown enlarged in FIG. 1D.

The conventional LC filter array as described above has the following problems.

First, since the pattern is formed in an asymmetric type that requires the input and output terminals to be distinguished, the LC filter array product must be distinguished and aligned when mounting the LC filter array product on a PCB. It must be provided separately. Therefore, there is a problem in that the cost is increased in the production of the equipment and the work process is added.

Second, since a plurality of capacitor patterns are all present in one sheet, there is a problem that there is a limit in adjusting the area and length of the capacitor pattern to realize a higher capacity product, if necessary.

Third, since the signal input of the capacitor pattern is formed only on one side, the attenuation characteristic of the product may vary depending on the direction in which the product is placed, and the position of the capacitor terminals within the magnetic path diameter of the coil formed by the inductor pattern. There is a problem that the difference in capacitance value between terminals due to the difference in the degree of influence of the parasitic capacitance is different.

Fourth, there is a problem in that the attenuation characteristics deteriorate due to parasitic inductor components parasitic to the capacitor in the high frequency region. 2 is a graph showing attenuation characteristics of a conventional LC filter array. As shown in FIG. 2, the conventional LC filter array has a second-order resonance (A) at about 1.4 GHz to 2.0 GHz, resulting in deterioration of attenuation characteristics. Such secondary resonance is caused by a parasitic inductor component, which causes the conventional LC filter array to be unsuitable for use as a filter in the high frequency region of 1,4 GHz or more.

The present invention has been made to solve the above problems, its purpose is to form a pattern in a symmetrical form does not need to distinguish between the input terminal and the output terminal, it is possible to easily adjust the area and length of the capacitor pattern, The present invention provides a stacked LC filter array having excellent attenuation characteristics in a wide frequency range without reducing attenuation characteristic due to changes in input and output impedances.

In order to achieve the above technical problem, the present invention, a plurality of input and output terminals are formed on one side, the same number of input and output terminals are formed symmetrically on the other side of the opposite side, the ground terminal on the side where the input and output terminals are not formed In the stacked LC filter array,

A first inductor unit formed by stacking one or more sheets having a predetermined conductive pattern forming at least one inductor electrically connected at both ends to the pair of input / output terminals facing each other;

A second inductor unit formed by stacking one or more sheets having a predetermined conductive pattern forming at least one inductor electrically connected at both ends thereof to a pair of input / output terminals opposed to each other without an inductor formed in the first inductor unit; ; And

At least one ground layer having a pattern electrically connected to the ground terminal, and an input / output terminal electrically connected to both ends of the inductor formed at the first inductor, respectively, and forming a capacitance between the connected input / output terminal and the ground layer. A first capacitor layer having a capacitance pattern formed thereon and an input / output terminal electrically connected to both ends of the inductor formed in the second inductor unit, the first capacitor layer having a capacitance pattern forming capacitance between the connected input / output terminal and the ground layer. A capacitor portion having two capacitor layers,

The capacitor part is formed under the first inductor part, and the second inductor part is formed under the capacitor part.

In the stacked LC filter array according to the present invention, the capacitance pattern is connected to a pair of input / output terminals facing each other, and preferably has a symmetrical shape, and the capacitance pattern is an input / output terminal connected to the corresponding capacitance pattern. It is preferably formed so as to be located within the magnetic path formed by the inductor electrically connected to the.

The ground layer may include a first ground layer formed on the first capacitor layer, a second ground layer formed between the first capacitor layer and the second capacitor layer, and a lower portion of the second capacitor layer. It is preferred to include a third ground layer to be.

The inductor of the first inductor and the inductor of the second inductor may be connected to adjacent terminals. The inductor may be formed such that magnetic flux generated by the inductor is directed toward the at least one ground layer. desirable.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3A is an external perspective view of a stacked LC filter array incorporating four LC filters, and FIG. 3B is an equivalent circuit diagram of a stacked LC filter array according to the present invention. 3A and 3B, in the stacked LC filter array according to the exemplary embodiment of the present invention, a plurality of input / output terminals t1 to t4 are formed on one side thereof, and the same number of input and output terminals A stacked LC filter array in which t1 'to t4' are formed symmetrically, and ground terminals g1 and g2 are formed on side surfaces where the input / output terminals t1 to t4 and t1 'to t4' are not formed. A first inductor portion 31a formed by stacking one or more sheets having a predetermined conductive pattern forming at least one inductor electrically connected at both ends to a pair of input / output terminals, and formed in the first inductor portion 31a. At least one sheet having a predetermined conductive pattern for forming at least one inductor electrically connected at both ends thereof is laminated on a pair of input / output terminals facing each other without an inductor connected thereto. A plurality of ground layers 32a, 32b, and 32c having a pattern electrically connected to the grounded second inductor portion 31b and the ground terminal, and to each input / output terminal to which the inductor formed in the first inductor portion 31a is connected. A first capacitor layer 33a having a capacitance pattern formed therebetween to form a capacitance between the ground layers 32a, 32b, and 32c, and an inductor formed in the second inductor portion 31b. And a second capacitor layer 33b having a capacitance pattern forming a capacitance between the ground layers 32a, 32b, and 32c, and formed between the first inductor portion 31a and the second inductor portion 31b. Provided is a stacked LC filter array comprising a capacitor portion.

As shown in Fig. 2A, the appearance of the present embodiment is that four input / output terminals t1 to t4 are formed on one side of the stacked LC filter array and four input / output terminals t1 'are symmetrically on the other side facing the stacked LC filter array. To t4 ') are formed. Ground terminals g1 and g2 are formed on the side surfaces on which the input / output terminals are not formed.

As shown in Fig. 2B, the interior of the present embodiment includes a first inductor portion 31a, a second inductor portion 31b, and capacitor portions 32a, 32b, 32c, 33a, and 33b. The first inductor part 31a is formed by stacking one or more sheets having a predetermined conductive pattern forming two inductors electrically connected at both ends to a pair of opposing input / output terminals t1 and t1 'and t3 and t3'. It is done by That is, one of the two inductors formed in the first inductor unit 31a has both ends connected to the input / output terminals t1 and t1 ', and the other inductor has both ends connected to the input / output terminals t3 and t3'. Connected.

Similarly, one inductor of two inductors formed in the second inductor part 31b is connected at both ends thereof to the input / output terminals t2 and t2 ', and the other inductor is connected at both ends thereof to the input / output terminals t4 and t4'. )

As such, the input / output terminals t1 and t1 ', t3 and t3' to which the inductor of the first inductor unit 31a is connected, and the input / output terminals t2, t2 ', t4 and t4 to which the inductor of the second inductor unit 31b is connected. ') Is preferably formed to be adjacent to each other. In other words, an inductor connected to the first terminal pair t1 and t1 'is formed in the first inductor portion, and the second terminal pair t2 and t2' neighboring the first terminal pair t1 and t1 '. The inductor connected to is formed in the second inductor portion, the inductor connected to the third terminal pair (t3, t3 ') adjacent to the second terminal pair (t2, t2') is formed in the first inductor portion, The inductor connected to the fourth terminal pair t4 and t4 'adjacent to the third terminal pair t3 and t3' is preferably formed in the second inductor unit. This is to allow the inductor pattern structure to prevent crosstalk by spacing the distance between the inductors as much as possible.

In addition, the inductors formed in the inductor sections 31a and 31b preferably form winding directions so that the magnetic flux generated by each inductor faces the ground layer. This is to minimize the influence on adjacent components by allowing all magnetic lines generated in the inductor to flow toward the ground layer and exit through the ground layer.

The capacitor unit includes three ground layers 32a, 32b, and 32c having patterns electrically connected to the ground terminals, and each input / output terminal t1, t1 ', t3 to which the inductor formed in the first inductor unit 31a is connected. , t3 ') and each input / output terminal having a first capacitor layer 33a having a capacitance pattern formed therebetween to form a capacitance between the ground layers 32a and 32b, and an inductor formed in the second inductor portion 31b. and a second capacitor layer 33b connected to (t2, t2 ', t4, t4') and having a capacitance pattern forming a capacitance between the ground layers 32b and 32c. The ground layers 32a, 32b, and 32c may be formed of three layers of the first ground layer 32a, the second ground layer 32b, and the third ground layer 32c, and the first capacitor layer 31a. Is located between the first ground layer 32a and the second ground layer 32b, and the second capacitor layer 31b is preferably located between the second ground layer 32b and the third ground layer 32c. . The capacitor portion is formed between the first inductor portion 31a and the second inductor portion 31b.

As shown in an enlarged view in FIG. 3D, four capacitor patterns are formed in the first capacitor layer 33a and the second capacitor layer 33b, respectively. Capacitive patterns C1 and C1 'having symmetrical shapes are connected to input / output terminals t1 and t1' connected to one of the two inductors formed in the first inductor part 31a, respectively. Capacitive patterns C3 and C3 'having symmetrical shapes are connected to the input / output terminals t3 and t3' connected to the inductor, respectively. Similarly, capacitive patterns C2 and C2 'having symmetrical shapes are connected to input / output terminals t2 and t2' connected to one of the two inductors formed in the second inductor part 31b, respectively. Capacitive patterns C4 and C4 'having symmetrical shapes are connected to input / output terminals t4 and t4' connected to one inductor, respectively.

As described above, the capacitor patterns are connected to each input / output terminal one by one, and two capacitor layers are formed on one side of the two capacitor layers and are symmetrical with the capacitance patterns formed on the opposite side. Compared to the capacitor layer used in the conventional stacked LC filter array (see FIG. 1D), the capacitor layer used in the stacked LC filter array according to the embodiment of the present invention uses two capacitor layers and each capacitor layer is used. By symmetrically forming two capacitors on each side of the circuit, directionality is removed from the terminals connected to both ends of the inductor, and the area where the capacitor pattern can be formed can be secured more widely.

In addition, the capacitance pattern is preferably formed to be located within the magnetic path diameter of the inductor electrically connected to the input and output terminals connected to the capacitance pattern. In other words, of the plurality of filters constituting the stacked LC filter array according to the present invention, one filter is composed of one inductor and two capacitance patterns, and the region in which the capacitance pattern is formed is applied to the filter of the capacitance pattern. It is preferably formed to be located within the magnetic path diameter of the belonging inductor. This is because when the capacitance pattern is located in the magnetic path diameter of another inductor, parasitic components that are parasitic from the other inductor are additionally added, which may cause variation in frequency characteristics between terminals, and the capacitance of the other filter may be changed. Because there is.

An equivalent circuit diagram of a stacked LC filter array according to an embodiment of the present invention configured as described above is shown in FIG. 3C. As shown in FIG. 3C, a stacked LC filter array according to an exemplary embodiment of the present invention includes four filters, and each filter includes one inductor connected to a pair of input / output terminals facing each other, and a ground at both input / output terminals. It consists of two capacitors connected to each other. In such a configuration, the filter has a symmetric circuit structure, and thus it is not necessary to distinguish between the input terminal and the output terminal. Therefore, it is not necessary to form a mark for distinguishing directions as in the conventional LC filter array, and it is not necessary to separately provide a mark sorting sensor when the product is mounted on a PCB or the like. In addition, since the capacitor-inductor-capacitor has a double parallel structure and has a distributed constant type, the attenuation characteristic does not change significantly even when an impedance difference between the input and output terminals is present in the circuit.

4 is a graph of attenuation characteristics of a stacked LC filter array according to an embodiment of the present invention. Compared with the attenuation characteristics of the conventional LC filter array (see FIG. 2), the conventional LC filter array has a poor attenuation due to the second-order resonance in the region of about 1.4 GHz to 2.0 GHz, but the stacked LC according to the present invention. As shown in 'A' of FIG. 4, the filter array has almost no second-order resonance in the region of about 1.4 GHz to 2.0 GHz.

In the conventional LC filter array, since one capacitor is connected in parallel to one inductor, as the frequency increases, after the first resonance by the inductor occurs, the inductance parasitic to the capacitor in the region where the frequency is higher is 2 Differential resonances occur. On the other hand, the stacked LC filter array according to an embodiment of the present invention has a structure in which capacitors are connected in parallel at both ends of the inductor and only two capacitors connected in parallel to one end of the inductor are formed so that the internal pattern is parasitic. The effect of secondary resonances due to inductance is greatly reduced and attenuation over broadband can be achieved.

As described through the above embodiment, the stacked LC filter array according to the present invention can remove the directivity of the terminal, can easily adjust the area and the length of the capacitance pattern within the limited area, and one inductor When two capacitors are connected in parallel to each other and noise is introduced into the filter, high-frequency noise that passes through the inductor and the capacitor without being filtered first can be bypassed once more, and the secondary of the inductor Resonance can be suppressed to a large extent, resulting in good attenuation characteristics at broadband.

As such, the present invention is not limited by the above-described embodiments and the accompanying drawings, and is intended to be limited by the appended claims, and various forms of substitution may be made without departing from the technical spirit of the present invention described in the claims. It will be apparent to one of ordinary skill in the art that modifications, variations and variations are possible.

As described above, according to the present invention, since it is not necessary to distinguish the input / output of the stacked LC filter signal terminal, the directionality is removed, and thus it is not necessary to form a separate direction indication mark. Since there is no need to use, there is an effect that can simplify the manufacturing cost and subsequent application process of the product itself. In addition, by easily adjusting the area and length of the capacitor pattern in the stacked LC filter array, it is possible to implement the desired capacitance as needed, it is possible to reduce the variation in capacitance value between the plurality of capacitors. In addition, since the internal structure has a distributed constant type, the deterioration of the attenuation characteristic due to the difference in the input / output circuit impedance can be suppressed, and an excellent attenuation characteristic can be obtained in a wide high frequency band.

1A is an external perspective view of a conventional stacked LC filter array.

1B is an equivalent circuit diagram of a conventional stacked LC filter array.

1C is a pattern diagram of a conventional stacked LC filter array.

1D is an enlarged view of a capacitor pattern of a conventional stacked LC filter array.

2 is a graph of attenuation characteristics of a conventional stacked LC filter array.

3A is an external perspective view of a stacked LC filter array according to an embodiment of the present invention.

3B is a pattern diagram of a stacked LC filter array in accordance with one embodiment of the present invention.

3C is an equivalent circuit diagram of a stacked LC filter array in accordance with one embodiment of the present invention.

3D is an enlarged view of a capacitor pattern of a stacked LC filter array in accordance with one embodiment of the present invention.

4 is a graph of attenuation characteristics of a stacked LC filter array according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

31a, 31b: inductor section 32a, 32b, 32c: ground layer

33a, 33b: capacitor layer

Claims (7)

In a stacked LC filter array in which a plurality of input / output terminals are formed on one side, the same number of input / output terminals are symmetrically formed on the other side thereof opposite, and a ground terminal is formed on the side where the input / output terminal is not formed. A first inductor unit formed by stacking one or more sheets having a predetermined conductive pattern forming at least one inductor electrically connected at both ends to the pair of input / output terminals facing each other; A second inductor unit formed by stacking one or more sheets having a predetermined conductive pattern forming at least one inductor electrically connected at both ends thereof to a pair of input / output terminals opposed to each other without an inductor formed in the first inductor unit; ; And At least one ground layer having a pattern electrically connected to the ground terminal, and an input / output terminal electrically connected to both ends of the inductor formed at the first inductor, respectively, and forming a capacitance between the connected input / output terminal and the ground layer. A first capacitor layer having a capacitance pattern formed thereon and an input / output terminal electrically connected to both ends of the inductor formed in the second inductor unit, the first capacitor layer having a capacitance pattern forming capacitance between the connected input / output terminal and the ground layer. A capacitor portion having two capacitor layers, And the capacitor portion is formed under the first inductor portion, and the second inductor portion is formed under the capacitor portion. The method of claim 1, wherein the capacitance pattern, A stacked LC filter array, each connected to a pair of input / output terminals facing each other, and having a symmetrical shape. The method of claim 1, wherein the capacitance pattern, Stacked LC filter array, characterized in that formed in the magnetic path diameter formed by the inductor electrically connected to the input and output terminals connected to the capacitance pattern. The method of claim 1, wherein the ground layer, A first ground layer formed on the first capacitor layer; A second ground layer formed between the first capacitor layer and the second capacitor layer; And And a third ground layer formed under the second capacitor layer. The method of claim 1, The LC filter array of claim 1, wherein the inductor of the first inductor and the inductor of the second inductor are connected to adjacent terminals. The method of claim 1, wherein the inductor, And a magnetic flux generated by the inductor toward the at least one ground layer. In a stacked LC filter array in which first to fourth input / output terminal pairs consisting of two terminals facing each other on both sides are formed in order, and a ground terminal is formed on a side on which an input / output terminal is not formed, A first inductor unit formed by stacking one or more sheets having a predetermined conductive pattern forming two inductors electrically connected to both ends of the first and third input / output terminal pairs; A second inductor unit formed by stacking one or more sheets having a predetermined conductive pattern forming two inductors electrically connected at both ends of the second and fourth input / output terminal pairs; And A first ground layer having a pattern electrically connected to the ground terminal, and a fourth ground layer formed under the first ground layer and electrically connected to four input / output terminals included in the first and third input / output terminal pairs, respectively, A first capacitor layer having a capacitance pattern forming a capacitance between the four input / output terminals included in the first and third input / output terminal pairs and the first ground layer, and a second ground layer formed below the first capacitor layer And electrically connected to four input / output terminals included in the second and fourth input / output terminal pairs, respectively, and a capacitance between the four input / output terminals included in the second and fourth input / output terminal pairs and a third ground layer described below. A capacitor part having a second capacitor layer having a capacitance pattern forming a capacitor, and a third ground layer formed under the second capacitor layer, And the capacitor portion is formed under the first inductor portion, and the second inductor portion is formed under the capacitor portion.