Transmission line type noise filter with reduced heat generation even when large dc current flows th

专利摘要:
PURPOSE: A transmission line type noise filter is provided to reduce heat generation even when a large DC current flows therein and to obtain excellent noise removing characteristic over a wide band, high frequency band, a small size and a simple structure. CONSTITUTION: A transmission line type noise filter is connectable between a direct current power supply(70) and an electrical load component(80) to pass a coming DC current while attenuating a coming AC current. The noise filter comprises a first conductor, a dielectric layer, a second conductor(20) as a cathode, a first anode(12), and a second anode(13). The first and the second conductors(20) and the dielectric layer serve as a capacitance forming portion. The thickness of the first conductor is selected to substantially restrict temperature elevation of the first conductor, which is caused by DC direct current flowing in the first conductor.
公开号:KR20040012549A
申请号:KR1020030052694
申请日:2003-07-30
公开日:2004-02-11
发明作者:사토시 아라이；다카유키 이노이；요시히코 사이키；사다무 도이타
申请人:엔이씨 도낀 가부시끼가이샤；
IPC主号:

专利说明:

TRANSMISSION LINE TYPE NOISE FILTER WITH REDUCED HEAT GENERATION EVEN WHEN LARGE DC CURRENT FLOWS THEREIN
[13] The present invention relates to a noise filter for removing noise mounted on an electronic device or electronic equipment.
[14] Digital technology is an important technology supporting the IT industry. Recently, LSI (large-scale integration) digital circuit technology is used not only for computer and communication-related devices but also for home appliances and vehicle equipment.
[15] However, the high frequency noise current generated in the LSI chip or the like spreads from the LSI chip to a wide range within the circuit board on which the chip is mounted by electrical transmission including inductive coupling with signal wiring on the circuit board or ground wiring. Radiated as electromagnetic waves around a circuit board from a cable or the like.
[16] In circuits comprising analog circuitry and digital circuitry, electromagnetic interference from digital circuitry to analog circuitry has been a serious problem.
[17] As a countermeasure, the power decoupling technique is effective, in which the LSI chip, which is the source of high frequency current, is separated from the DC power at high frequency. As the decoupling component, a noise filter such as a bypass capacitor has been used. The principle of power decoupling is simple.
[18] The capacitor used as a noise filter in a conventional AC circuit forms a two-terminal lumped constant noise filter. Therefore, solid electrolytic capacitors, electric double layer capacitors, ceramic capacitors and the like are often used.
[19] When removing electrical noise in an AC circuit over a wide frequency band, the frequency band that can be covered by one capacitor is narrow, so that several types of capacitors, for example ceramic capacitors with various magnetic resonance frequencies, tantalum capacitors and aluminum An electrolytic capacitor is provided in the AC circuit.
[20] However, conventionally, selecting and designing a large number of noise filters used to remove electrical noise in a wide frequency band has been a cumbersome task. In addition, the use of various types of noise filters increases the cost of the circuit, increases the size, and increases the weight.
[21] In addition, in order to process high speed and high frequency digital circuits, a noise filter having a decoupling reliably over a high frequency band and having a low impedance even at a high frequency band is required.
[22] However, the two-terminal lumped integer noise filter is difficult to maintain low impedance even in the high frequency region due to the magnetic resonance phenomenon of the capacitor, and thus has low performance in removing high frequency band noise.
[23] Therefore, the noise filter should have excellent noise rejection characteristics, small size, and simple structure in a wide band including a high frequency band.
[24] In order to respond to the above characteristics, a transmission line type noise filter that can be connected between a power supply and an electrical component such as an LSI chip and allows DC current to pass while attenuating incoming AC current is noted.
[25] However, since the direct current to be supplied to the electrical components passes through the transmission line noise filter, heat is generated in the transmission line noise filter. Therefore, the transmission line type noise filter generates a serious heat for use in an electric circuit with a large direct current, so the life is shortened.
[26] Accordingly, an object of the present invention is to provide a transmission line type noise filter with low heat generation even when a large direct current flows.
[27] Another object of the present invention is to provide a transmission line type noise filter having excellent noise removal characteristics, a small size, and a simple structure even in a wide frequency band including a high frequency band.
[1] 1A, 1B and 1C are diagrams illustrating an exemplary structure of a transmission line noise filter according to a preferred embodiment of the present invention, in which FIG. 1A is a plan view, and FIG. 1B is a sectional view taken along 1B-1B of FIG. 1C is a cross-sectional view taken along 1C-1C in FIG. 1A.
[2] 2 is a perspective view schematically showing a first conductor in a transmission line noise filter according to the present invention.
[3] 3 is a graph showing the results of a test for examining the relationship between the thickness of the first conductor and the temperature rise for each of the various materials used in the transmission line noise filter according to the present invention.
[4] 4 is a graph showing the results of another test for examining the relationship between the temperature and the thickness and length of the first conductor used in the transmission line noise filter according to the present invention.
[5] Fig. 5 is a graph showing the results of another test for examining the relationship between the width and length of the first conductor and the temperature rise used in the transmission line noise filter according to the present invention.
[6] 6 is a graph showing the results of another test for examining the relationship between the thickness of the first conductor and the temperature rise used in the transmission line noise filter according to the present invention.
[7] Explanation of symbols on the main parts of the drawings
[8] 10 .... Etched aluminum foil 11 .... First conductor (11)
[9] 12 .... first anode 13 .... second anode
[10] 20 .... Secondary conductor 30 .... Dielectric layer
[11] 50 .... Capacitance forming part 70 .... Power
[12] 80 .... Electrical components 90 .... Circuit board
[28] The transmission line noise filter according to the present invention may be connected between the direct current (DC) power source 70 and the electrical component 80, and the DC current may pass while the incoming AC current is attenuated. The transmission line noise filter is formed of a plate, and has a length L along a first direction X parallel to the transmission line and a second direction Y perpendicular to the first direction X. A dielectric layer formed on the first conductor 11 and the first conductor 11 having a width W and a third direction Z perpendicular to the first and second directions X and Y 30, the second conductor 20 formed on the dielectric layer 30, and one end of the first conductor 11 are connected in a first direction X to connect the first conductor 11 to a direct current power source. A first positive electrode 12 connected to 70 and the other end of the first conductor 11 are connected in a first direction X to connect the first conductor 11 to the electrical component 80. And a second anode 13. The second conductor 20 acts as a cathode connectable to the standard electrode. The first conductor 11, the second conductor 20, and the dielectric layer 30 serve as a capacitance forming portion 50. The thickness t of the first conductor 11 is selected so as to significantly suppress the temperature rise formed by the direct current flowing through the inside.
[29] The first conductor 11 is made with the valve acting metal as an essential component, and the oxidized film of the valve acting metal can make the dielectric layer 30.
[30] In one embodiment the valve acting metal is aluminum and the thickness t of the first conductor 11 is selected not to exceed 2.0 nm.
[31] In another embodiment the valve acting metal is tantalum and the thickness t of the first conductor 11 is chosen not to exceed 1.5 nm.
[32] In another embodiment the valve acting metal is niobium and the thickness t of the first conductor 11 is selected so as not to exceed 1.0 nm.
[33] In a preferred embodiment, the first conductor 11, the first electrode 12, and the second electrode 13 are formed in an integral metal plate shape.
[34] Other objects, features and advantages of the invention will be apparent from the detailed description herein.
[35] Hereinafter, exemplary embodiments of a transmission line noise filter according to the present invention will be described with reference to the accompanying drawings.
[36] 1A to 1C, a transmission line noise filter according to an exemplary embodiment of the present invention may be connected between a DC power supply 70 and an LSI chip 80, which is an electrical component, and attenuates incoming AC. Direct current can pass.
[37] The transmission line noise filter includes a first conductor 11, a dielectric layer 30, a second conductor 20, a first positive electrode 12, and a second positive electrode 13.
[38] The first conductor 11 has a plate shape and has a length L along a first direction X parallel to the transmission line and a width along a second direction Y perpendicular to the first direction X. W) and a third direction Z perpendicular to the first direction X and the second direction Y. FIG. The dielectric layer 30 is formed as a film on and around the first conductor 11 in such a manner that both ends in the first direction X of the first conductor 11 face each other. The second conductor 20 is also formed on the dielectric layer 30 as a film layer. The first anode 12 is connected to one end of the first conductor 11 in the first direction X. The second anode 13 connects the first conductor 11 to the DC power supply 70. The second anode 13 is connected to the other end of the first conductor 11 in the first direction X. The second anode 13 connects the first anode 11 to the LSI chip 80. Furthermore, the second conductor 20 acts as a cathode connectable to the ground line, which is a standard potential.
[39] For example, the first conductor 11 used for the transmission line noise filter as a product has a length L of 7.3 or 15.0 mm and a width W of 4.3 or 11.0 mm.
[40] The first conductor 11, the second conductor 20, and the dielectric layer 30 serve as the capacitance forming unit 50.
[41] The first conductor 11, the first anode 12, and the second anode 13 may be integrally formed by a plate-etched aluminum foil 10.
[42] The first positive electrode 12, the second positive electrode 13, and the second conductive electrode 20, which is the negative electrode, include the first lands 41, the second lands 42, and the first lands formed on the circuit board 90 by welding. It is mounted on the three lands 43 and is electrically connected. The first land 41 and the second land 42 are connected to the output terminal of the DC power supply 70 and the input terminal of the LSI chip, respectively. The third land 43 is connected to a ground line (not shown), which is a standard potential common to the DC power supply 70 and the LSI chip 80.
[43] The transmission line type noise filter covers (filters) the resin with the resin except for the connection portions of the first anode 12, the second anode 13, and the second conductor 20, that is, the terminals (not shown). It can be configured as an electric chip.
[44] Aluminum (Al), which is the material of the etched aluminum foil 10, is a valve acting metal. Thus, dielectric layer 30 may be formed by an oxidized aluminum film of etched aluminum foil 10, which is first conductor 11. The thickness of dielectric layer 30 is, for example, 1 μm, but is shown thicker than the actual thickness in FIGS. 1B and 1C to facilitate understanding of the relationship between the components of the filter of the present invention. In contrast, the second conductor 20 has a silver coating layer formed on the solid electrolytic capacitor, the graphite layer, and the dielectric layer 30 in this order. The thickness of the second conductor 20 is, for example, 50 [mu] m, but this too is shown thicker than the actual thickness in FIGS. 1B and 1C.
[45] The reason why the aluminum foil is etched is to obtain high capacitance by making the surface rough and widening the surface area of the dielectric oxide film formed thereon.
[46] In the present invention, the valve acting metal is not limited to aluminum, and tantalum (Ta) or niobium (Nb) may also be used. When Ta or Nb is used, the first conductor 11 is formed of a raw sheet of tantalum or niobium or a sintered powder in vacuum. Tantalum and niobium sintered bodies have a rough surface, and thus the surface area thereof is relatively large. Therefore, the area of the oxidized film, which is the dielectric layer 30 formed on the surface of the sintered body, is also relatively large. Therefore, a transmission line type noise filter having a large capacitance can be obtained.
[47] The thickness t of the first conductor 11 should be selected so as to substantially limit the temperature rise due to heat generation when a direct current flows therein. This will be described in detail below.
[48] The transmission line type noise filter connected between the DC power supply 70 and the LSI chip 80 through the circuit board 90 passes the DC current while attenuating the incoming AC current. That is, the DC current supplied to the LSI chip 80 flows into the etched aluminum foil in the form of a metal sheet.
[49] DC is input into the first land 41, flows through the first anode 12, the first conductor 11, and the second anode 13, and is then output from the second land 42. In this case, Joule heat is generated in the etched aluminum foil 10, in particular in the first conductor 11. Therefore, the temperature of the transmission line noise filter increases. The temperature rise of the transmission line type noise filter causes a problem of shortening the lifetime.
[50] Hereinafter, the temperature rise of the first conductor 11 by the DC current and the solution according to the present invention will be described.
[51] 2 is a schematic perspective view of the first conductor 11. The first conductor 11 has a length L, a width W, and a thickness t. The direct current flows in the first direction X as can be clearly seen in FIG. 2.
[52] The amount of heat generated in the first conductor 11 is proportional to the resistance of the first conductor 11. When the shape and size of the first conductor 11 in the plan view are constant, its electrical resistance is inversely proportional to the thickness t. Therefore, when the thickness t of the first conductor 11 is increased, the amount of heat generated is reduced. On the other hand, when the thickness t of the first conductor 11 is increased, the amount of heat radiation is reduced. The inventors have found an appropriate range of thicknesses t that can balance the amount of heat generated in the first conductor 11 with the amount of heat emitted from the first conductor 11. The appropriate thickness range of the first conductor 11 was found by the following investigation.
[53] 3 shows test results for several temperature rises of the first conductor 11. In the test, various samples of the first conductor 11 were made with etched aluminum foil of 99.96% purity. These various samples all varied from 1 cm in length, 1 cm in width, and 0.01-5.0 mm in thickness. To examine the relationship between the thickness t and the temperature rise, a direct current of 30 A was applied continuously through each sample for 60 seconds, which is sufficient for the temperature of each sample to stabilize. The test results are shown in FIG. In FIG. 3, the thickness t of the first conductor 11 manufactured by using aluminum as an essential component should be 2.0 mm or less, which should considerably limit the temperature rise.
[54] Similar investigations were also made for other samples of the first conductor 11 manufactured using tantalum and niobium as essential components, respectively. The test results are shown in FIG.
[55] As a result, in FIG. 3, the thickness t of the first conductor 11 manufactured using tantalum as an essential component in order to limit the temperature increase considerably is preferably 1.5 mm or more. In addition, the thickness t of the first conductor 11 manufactured using niobium as an essential component is preferably 1.0 mm or more.
[56] 4 is the result of another test investigating the effect of the length L on the relationship between the temperature rise of the first conductor 11 and the thickness t. In the test, various samples were made with aluminum foil of 99.96% etched purity. The different samples had lengths (L) of 0.5 cm, 1.0 cm, 2.0 cm and 4.0 cm, the same width of 1 cm, and a thickness of 0.01 to 5.0 mm. A direct current of 30 A was applied to each sample continuously for 60 seconds, which is enough time for the temperature of each sample to be established. The test results are shown in FIG. In FIG. 4, the length of the first conductor 11 hardly affects the relationship between the temperature rise and the thickness t. In order to suppress the temperature rise considerably, the first conductor made of aluminum is an essential component ( It can be seen that the thickness of 11) should be selected from 2.0mm or less.
[57] 5 shows the results of another test for investigating any effect of the width W of the first conductor 11 on the relationship between the temperature rise and the thickness t of the first conductor 11. . In this test, various samples were made from etched aluminum foil of 99.96% purity. The various samples were equal in length 1 cm, width 0.2 cm, 0.5 cm, 1.0 cm and 1.5 cm and thickness varied from 0.01 to 5.0 cm. A direct current of 30 A was applied to each sample continuously for 60 seconds, which is enough time for the temperature of each sample to be established. The test results are shown in FIG. In FIG. 5, the difference in width W of the first conductor 11 affects the temperature rise in the thickness region exceeding 2.0 mm, but the thickness of the first conductor 11 is limited in order to limit the temperature rise considerably. It can be seen that should be selected to 2.0mm or less.
[58] 6 shows further test results of examining the influence of the direct current applied to the first conductor 11. In this test, various samples were made from etched aluminum foil of 99.96% purity. The various samples were the same in length, 1 cm, the width in 1.0 cm, and the thickness varied from 0.01 to 5.0 cm. Direct currents of 5 A, 10 A and 30 A were applied to each sample continuously for 60 seconds. The test results are shown in FIG. In FIG. 6, the difference in the width W of the first conductor 11 affects the temperature rise in the thickness region exceeding 2.0 mm, but is manufactured using aluminum as an essential component in order to limit the temperature increase considerably. It can be seen that the thickness of the first conductor 11 should be selected to 2.0 mm or less.
[59] In order to stabilize the mechanical strength of the first conductor 11, the thickness of the first conductor 11 made of a material such as aluminum, tantalum or niobium is preferably not thinner than several micrometers.
[60] While the invention has been described with reference to various embodiments, those skilled in the art will be able to practice the invention in various ways.
[61] For example, the noise filter according to the present invention may be connected to the LSI and packaged together with the LSI in a general package made of resin, so that an LSI chip having a noise filter may be constructed.
[62] According to the transmission line noise filter of the present invention described above, a transmission line noise filter with less heat generation even when a large direct current flows is provided.
[63] In addition, a transmission line type noise filter having excellent noise removal characteristics, a small size, and a simple structure is provided even in a wide frequency band including a high frequency band.

权利要求:
Claims (6)
[1" claim-type="Currently amended] As a transmission line type noise filter that can be connected between the DC power supply 70 and the electric component 80, the DC current passes while the incoming AC current is attenuated.
It has a plate shape, the length (L) along the first direction (X) parallel to the transmission line, the width (W) along the second direction (Y) perpendicular to the first direction (X), and the first A first conductor 11 having a third direction Z perpendicular to the first direction X and the second direction Y;
A dielectric layer 30 formed on the first conductor 11;
A second conductor 20 formed on the dielectric layer 30;
A first anode 12 connected to one end of the first conductor 11 in a first direction X to connect the first conductor 11 to a DC power supply 70;
A second anode (13) connected to the other end of the first conductor (11) in a first direction (X) to connect the first conductor (11) to the electrical component (80);
The second conductor 20 acts as a cathode connectable to a standard electrode;
The first conductor 11, the second conductor 20, and the dielectric layer 30 form a capacitance forming unit 50.
The transmission line type noise filter, wherein a thickness t of the first conductor 11 is selected to substantially suppress the temperature rise caused by the direct current flowing inside the first conductor 11.
[2" claim-type="Currently amended] The transmission line noise filter according to claim 1, wherein the first conductor (11) is made of a valve acting metal as an essential component, and the dielectric layer (30) is made of an oxidized film of the valve acting metal.
[3" claim-type="Currently amended] The transmission line type noise filter according to claim 2, wherein the valve action metal is aluminum, and the thickness t of the first conductor 11 is 2.0 mm or less.
[4" claim-type="Currently amended] The transmission line type noise filter according to claim 2, wherein the valve action metal is tantalum, and the thickness t of the first conductor 11 is 1.5 mm or less.
[5" claim-type="Currently amended] The transmission line type noise filter according to claim 2, wherein the valve action metal is niobium, and the thickness t of the first conductor 11 is 1.0 mm or less.
[6" claim-type="Currently amended] The transmission line noise filter according to claim 1, wherein the first conductive member (11), the first positive electrode (12) and the second positive electrode (13) are integrally formed in the form of a metal sheet.

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同族专利:

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CN100471056C|2009-03-18|

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US7005944B2|2006-02-28|

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GB0318004D0|2003-09-03|

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TW200405659A|2004-04-01|

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CN1476165A|2004-02-18|

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KR100635699B1|2006-10-17|

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GB2392314B|2006-03-15|

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TWI248257B|2006-01-21|

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GB2392314A|2004-02-25|

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US20040021528A1|2004-02-05|

引用文献:

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公开号 | 申请日 | 公开日 | 申请人 | 专利标题

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法律状态:
2002-07-31|Priority to JP2002222925

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2002-07-31|Priority to JPJP-P-2002-00222925

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2003-07-30|Application filed by 엔이씨 도낀 가부시끼가이샤

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2004-02-11|Publication of KR20040012549A

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2006-10-17|Application granted

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2006-10-17|Publication of KR100635699B1

优先权:

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申请号 | 申请日 | 专利标题

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JP2002222925|2002-07-31|

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JPJP-P-2002-00222925|2002-07-31|