JP2009026872A - Multilayer capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer capacitor wherein a lower ESL is realized. <P>SOLUTION: By having the end edges of drawn parts 15a and 16a of first and second inner conductor layers 15 and 16 constituting independent capacitor parts are exposed partially from both side surfaces of a body 11 between first and second outer electrodes 12 and 13, to which the drawn parts 15a and 16a of the first and second inner conductor layers 15 and 16 connected, the length of a current path from the drawn part 15a of one polarity to the drawn part 16a of the other polarity is shortened so that the inductance generated in the current path is lowered, while the drawn part 15a of one polarity and the drawn part 16a of the other polarity are made close to each other, for effective magnetic field cancelation action that is provided by the current that flows through the drawn parts 15a and 16a in the reverse directions. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a multilayer capacitor suitable for decoupling applications.

  A multilayer capacitor used for decoupling requires high capacitance and low ESL (equivalent series inductance). Patent Documents 1 and 2 disclose this type of multilayer capacitor.

  The multilayer capacitor disclosed in Patent Document 1 includes a rectangular parallelepiped main body and a total of eight external electrodes that are provided in a non-contact manner on each of both sides in the width direction of the main body and have four different polarities. The main body has a first inner conductor layer having a total of four lead portions provided on each side edge in the width direction and a total of four lead portions provided on each side edge in the width direction. It has a structure in which the second inner conductor layers having positions different from the lead portions of the one inner conductor layer are alternately laminated and integrated through the dielectric layers. The four lead portions of each first inner conductor layer are connected to four external electrodes of one polarity, and the four lead portions of each second inner conductor layer are connected to the remaining four external electrodes of the other polarity. ing.

On the other hand, the multilayer capacitor disclosed in Patent Document 2 has a structure in which each first inner conductor layer of the multilayer capacitor disclosed in Patent Document 1 is divided into two in the width direction and each second inner conductor layer is divided in two in the width direction. Yes.
Special table 2002-508114 gazette JP 2002-151349 A

  Since the capacitance of the multilayer capacitor can be basically adjusted by the number of laminated inner conductor layers, both of the multilayer capacitors disclosed in Patent Document 1 and Patent Document 2 can obtain sufficient capacitance suitable for decoupling applications. Can do.

  On the other hand, the ESL of the multilayer capacitor is determined by the overall structure of the multilayer capacitor. However, in the multilayer capacitors of Patent Document 1 and Patent Document 2, the direction of the current flowing through the different-polarity lead-out portions through the dielectric layer is determined. By making it reverse, the magnetic field generated by the current flowing through each lead-out portion is canceled out to reduce ESL.

  The ESL reduction method employed in the multilayer capacitors disclosed in Patent Document 1 and Patent Document 2 is to reduce the inductance generated in the current path from the one polarity lead portion to the other polarity lead portion by the magnetic field canceling action. If the length of the current path from the one-polarity lead part to the other-polarity lead part is shortened to reduce the inductance that can occur in the current path, the ESL can be further reduced. If the lead portion and the other polarity lead portion are brought close to each other so that the magnetic field canceling action can be effectively performed, the ESL can be further reduced.

  The present invention was created in view of the above circumstances, and an object of the present invention is to provide a multilayer capacitor in which ESL is further reduced.

  To achieve the above object, the present invention provides a multilayer capacitor in which a first external electrode having one polarity and a second external electrode having the other polarity are alternately provided in a non-contact manner on a side surface of a rectangular parallelepiped body. A plurality of first inner conductor layers arranged in a non-contact manner on the same plane and the same number of second inner conductor layers as the first inner conductor layers arranged in a non-contact manner on the same plane are alternately stacked via dielectric layers. A plurality of independent capacitor portions are constituted by the first and second internal electrode layers arranged in the stacking direction via the dielectric layers, and the first and second inner capacitor portions are respectively The second inner conductor layer has one lead portion at a different position on the same side edge, the lead portion of the first inner conductor layer of each independent capacitor portion is connected to the first outer electrode, and the second The lead portion of the inner conductor layer is connected to the second outer electrode adjacent to the first outer electrode. The first and second external conductors connected to the lead portions of the first and second inner conductor layers are connected to each other, and the edge portions of the lead portions of the first and second inner conductor layers of each independent capacitor portion are connected to each other. It is partially exposed on the side surface of the main body between the electrodes, and the exposed edge portion is covered with an insulating coating provided between the first and second external electrodes on the side surface of the main body. Is the feature.

  According to this multilayer capacitor, the first and second external electrodes to which the lead portions of the first and second internal conductor layers are connected to the end edges of the lead portions of the first and second internal conductor layers of each independent capacitor portion By partially exposing the side surface of the main body, the length of the current path from the one polarity lead portion to the other polarity lead portion can be shortened, and the inductance that can be generated in the current path can be reduced. In addition, it is possible to effectively cancel the magnetic field obtained by the current flowing in the opposite direction by bringing the one-polarity lead portion and the other-polarity lead portion close to each other, thereby further increasing the ESL of the multilayer capacitor. Can be reduced.

  According to the present invention, it is possible to provide a multilayer capacitor in which ESL is further reduced.

  The above object and other objects, structural features, and operational effects of the present invention will become apparent from the following description and the accompanying drawings.

[First Embodiment]
1 to 4 show a first embodiment of the present invention (multilayer capacitor). FIG. 1 is a perspective view of the multilayer capacitor, FIG. 2 is a left side view of the multilayer capacitor shown in FIG. 1, and FIG. 1 is a cross-sectional view of the multilayer capacitor shown in FIG. 1, and FIG. 4 is a perspective view showing the layer structure of the main body shown in FIG.

  The multilayer capacitor 10 includes a rectangular parallelepiped main body 11 having a predetermined length, width, and height, and a total of four first polarities provided in a non-contact manner on both side surfaces of the main body 11 in the width direction. A total of four insulation coating portions 14 provided between the external electrode 12 and the total of four second external electrodes 13 of the other polarity and the first and second external electrodes 12 and 13 on both side surfaces of the main body 11 in the width direction. And.

  Two first external electrodes 12 and two second external electrodes 13 are provided on each side surface in the width direction of the main body 11, and a total of four first, first and second external electrodes 12 are provided on one side surface (the right side surface in FIG. 1). The second external electrodes 12, 13 are arranged in the order of the first external electrode 12, the second external electrode 13, the first external electrode 12, and the second external electrode 13 from the left, and the other side surface of the main body 11 (the left side surface in FIG. 1). ), A total of four first and second external electrodes 12 and 13 are arranged from the left so as to face the first and second external electrodes 12 and 13 on one side surface. The two external electrodes 13 and the first external electrode 12 are arranged in this order.

  As shown in FIG. 4, the main body 11 includes two first inner conductor layers 15 arranged in a non-contact manner on the same plane, and the same number of second inner conductor layers 16 as the first inner conductor layers arranged in a non-contact manner on the same plane. Are alternately stacked through a dielectric layer DL and integrated. Each of the first inner conductor layers 15 and each of the second inner conductor layers 16 has a rectangular shape having substantially the same size, and is arranged in a non-contact manner in the same plane as the two first inner conductor layers 15 arranged in a non-contact manner in the same plane. The two second inner conductor layers 16 face each other in the stacking direction via the dielectric layer DL. In other words, in the main body 11, two independent capacitor portions (not shown) are spaced in the length direction by the first and second internal electrode layers 15 and 16 arranged in the stacking direction via the dielectric layer DL. It is configured.

  Each first inner conductor layer 15 has one lead portion 15a on one side edge in the width direction (right side edge in FIG. 4) and the other side edge in the width direction (left side edge in FIG. 4). The conductor layer 16 has one lead portion 15a on one side edge in the width direction (right side edge in FIG. 4) and the other side edge in the width direction (left side edge in FIG. 4). The lead portion 15a of each first inner conductor layer 15 and the lead portion 16a of each second inner conductor layer 16 form a rectangular shape having substantially the same size, and are arranged in a non-contact manner on the same plane. The positions of the lead portions 16a of the two second inner conductor layers 16 arranged in a non-contact manner in the same plane as the positions of the lead portions 15a differ in the length direction.

  As shown in FIG. 3, the lead-out portion 15a on one side edge (upper edge in FIG. 3) of each first internal electrode layer 15 constituting one independent capacitor portion (capacitor portion configured on the left side in FIG. 3) Connected to the first external electrode 12 located on the leftmost side of one side of the main body 11 (upper side of FIG. 3), the lead-out portion 15a on the other side edge (lower side edge of FIG. 3) 3 is connected to the first external electrode 12 located second from the left. Further, the lead-out portion 16a at one side edge (upper edge in FIG. 3) of each second internal electrode layer 16 constituting one independent capacitor portion (capacitor portion configured on the left side in FIG. 3) is one side surface of the main body 11. Connected to the second external electrode 13 located second from the left (upper side surface in FIG. 3), the lead-out portion 16a at the other side edge (lower side edge in FIG. 3) is connected to the other side surface of the main body 11 (lower side in FIG. 3). The second external electrode 13 located on the leftmost side of the side surface is connected.

  The lead-out portion 15a at one side edge (upper edge in FIG. 3) of each first internal electrode layer 15 constituting the other independent capacitor portion (capacitor portion configured on the right side of FIG. 3) is one side surface of the main body 11 (FIG. 3 is connected to the first external electrode 12 located at the third position from the left, and the lead portion 15a at the other side edge (lower side edge in FIG. 3) is the other side surface of the main body 11 (lower side face in FIG. 3). Is connected to the first external electrode 12 located fourth from the left. Further, the lead-out portion 16a at one side edge (upper edge in FIG. 3) of each second internal electrode layer 16 constituting one independent capacitor portion (capacitor portion configured on the right side in FIG. 3) is one side surface of the main body 11. Connected to the second external electrode 13 located fourth from the left (upper side surface in FIG. 3), the lead-out portion 16a at the other side edge (lower side edge in FIG. 3) is connected to the other side surface of the main body 11 (lower side in FIG. 3). The second external electrode 13 located third from the left side surface is connected.

  As shown in FIG. 3, a total of four first and second external electrodes 12 and 13 (two first external electrodes 12 and two first external electrodes 12 and two pieces provided on one side surface (upper side surface in FIG. 3) of the main body 11. The widths Wa of the second external electrodes 13) are all equal, and the inner edge intervals a1 to a3 of the adjacent first and second external electrodes 12 and 13 are also equal. Also, the widths Wb and Wc of the lead portions 15a and 16a of the first and second inner conductor layers 15 and 16 constituting each independent capacitor portion are all equal, and the widths Wb and Wc are larger than the width Wa. In addition, the inner edge intervals b1 and b2 of the lead portions 15a and 16a of the first and second inner conductor layers 15 and 16 constituting the independent capacitor portions are all equal and larger than zero, and both the lead portions 15a and 15a, 16a does not face in the stacking direction, and the inner edge intervals b1 and b2 are smaller than the inner edge intervals a1 to a3.

  That is, the leading edges 15a and 16a of the first and second inner conductor layers 15 and 16 constituting the independent capacitor sections are connected to the leading edges 15a and 16a of the first and second inner conductor layers 15 and 16, respectively. The first and second external electrodes 12 and 13 are partially exposed at the side surface of the main body 11.

  Although illustration of dimension lines and the like is omitted, the widths of the first and second external electrodes 12 and 13 on the other side of the main body 11 (the lower side of FIG. 3) and the adjacent first and second external electrodes 12 are omitted. , 13, the widths of the lead portions 15a and 16a of the first and second inner conductor layers 15 and 16 constituting the independent capacitor portions, and the first and second inner conductors constituting the independent capacitor portions, respectively. The inner edge intervals of the lead portions 15a and 16a of the layers 15 and 16 are the same as described above.

  Each insulation coating portion 14 is made of an insulating material, and as shown in FIGS. 2 and 3, the edges of the lead portions 15a and 16a of the first and second inner conductor layers 15 and 16 constituting the independent capacitor portions are formed. Between the first and second external electrodes 12 and 13 on both side surfaces of the body 11 that are partially exposed, the edge exposed portions are respectively covered with an insulating coating portion 14. Further, the thickness of each insulation coating portion 14 is smaller than the thickness of the first and second external electrodes 12 and 13.

  Each insulating coating portion 14 is preferably made of the same material as that of the dielectric layer DL constituting the main body 11. For example, when the dielectric layer DL is made of a barium titanate-based dielectric material, each insulating coating portion 14 is also formed of the same. It is preferable to use a barium titanate-based dielectric material having the same composition. If the material of each insulation coating portion 14 is the same as that of the dielectric layer DL constituting the main body 11, the same ceramic slurry as that of the dielectric layer DL is used on both sides of the unfired main body 11 after lamination and pressure bonding. The body 11 in which the insulating coating portion 14 is integrated can be obtained by simultaneously firing the insulating coating portion 14 formed.

  When the firing of the main body 11 and the firing of the external electrodes 12 and 13 need to be performed in separate processes due to the composition of the dielectric layer DL, the internal electrode layers 15 and 16 and the external electrodes 12 and 13, the unfired main body After forming the unsintered insulation coating portion 14 on 11 and simultaneously firing the unsintered main body 11 and the unsintered insulation coating portion 14, unfired external electrodes 12, 13 are formed on the body 11 using an electrode paste. What is necessary is just to bake. Further, in the case where the main body 11 and the external electrodes 12 and 13 can be simultaneously fired, the unfired insulation coating portion 14 and the unfired external electrodes 12 and 13 are formed on the unfired body 11 in the same or reverse order. The unfired main body 11, the unfired insulation coating portion 14, and the unfired external electrodes 12 and 13 may be fired simultaneously.

  In this multilayer capacitor 10, the edges of the lead portions 15a and 16a of the first and second inner conductor layers 15 and 16 constituting the independent capacitor portions are connected to the edges of the first and second inner conductor layers 15 and 16, respectively. By partially exposing both sides of the main body 11 between the first and second external electrodes 12 and 13 to which the lead portions 15a and 16a are connected, the lead portion 15a having one polarity and the lead portion 16a having the other polarity are exposed. The length of the current path can be shortened to reduce the inductance that can be generated in the current path, and the one-polarity lead portion 15a and the other-polarity lead portion 16a are brought close to each other and the lead portions 15a and 16a are reversed. The magnetic field canceling action obtained by the current flowing in the direction can be effectively performed, whereby the ESL of the multilayer capacitor 10 can be further reduced.

  Incidentally, according to an experiment, the end edges of the lead portions 15a and 16a of the first and second inner conductor layers 15 and 16 constituting the independent capacitor portions are connected to the main body 11 between the first and second outer electrodes 12 and 13, respectively. When the inner edge intervals b1 and b2 are set to 340 μm compared to the case where the inner edge intervals of the lead portions 15a and 16a are set to 400 μm without being exposed on the side surfaces of the It is added that the ESL reduction of about 30 pH could be achieved when the edge intervals b1 and b2 were 250 μm.

  Further, the exposed edge portions of the lead portions 15a and 16a of the first and second internal conductor layers 15 and 16 constituting each independent capacitor portion are between the first and second external electrodes 12 and 13 on both side surfaces of the main body 11. Since the end surface exposed portion is prevented from being touched by external air and denatured, moisture or the like enters the main body 11 through the end surface exposed portion, and thus has capacitor characteristics. Deterioration can also be prevented.

  Furthermore, since the thickness of each insulation coating portion 14 is smaller than the thickness of the first and second external electrodes 12 and 13, the first and second external electrodes 12 and 13 of the multilayer capacitor 10 are used as a circuit board. When connecting using solder, it is possible to prevent as much as possible that the adhesion area of the solder to each of the first and second external electrodes 12 and 13 is reduced due to the presence of each insulating coating portion 14.

[Second Embodiment]
5 and 6 show a second embodiment of the present invention (multilayer capacitor). FIG. 5 is a left side view of the multilayer capacitor corresponding to FIG. 2, and FIG. 6 is a diagram of the multilayer capacitor shown in FIG. FIG.

  The multilayer capacitor 10-1 differs from the multilayer capacitor 10 described above in that the widths Wb1 and Wc1 of the lead portions 15a1 and 16a1 of the first and second internal conductor layers 15 and 16 constituting the independent capacitor portions are the same as those of the multilayer capacitor 10-1. It is larger than the widths Wb and Wc of the lead portions 15a and 16a of the capacitor 10 and all have the same value, and the lead portions 15a1 and 16a1 of the first and second inner conductor layers 15 and 16 constituting each independent capacitor portion. The inner edge intervals b1 and b2 are both zero. Since other configurations are the same as those of the multilayer capacitor 10 described above, description thereof is omitted.

  In the multilayer capacitor 10-1, the inner edge intervals b1 and b2 of the lead portions 15a1 and 16a1 of the first and second inner conductor layers 15 and 16 constituting the independent capacitor portions are set to zero. The length of the current path from the polar lead part 15a1 to the other polar lead part 16a1 can be further shortened to further reduce the inductance that can be generated in the current path. The magnetic pole canceling action obtained by the current flowing in the reverse direction to the lead portions 15a1 and 16a1 can be more effectively performed by bringing the lead portion 16a1 of the polarity closer to each other, thereby further increasing the ESL of the multilayer capacitor 10-1. Can be reduced. Since other functions and effects are the same as those of the multilayer capacitor 10 described above, description thereof is omitted.

[Third Embodiment]
7 and 8 show a third embodiment of the present invention (multilayer capacitor). FIG. 7 is a left side view of the multilayer capacitor corresponding to FIG. 2, and FIG. 8 is a diagram of the multilayer capacitor shown in FIG. FIG.

  The multilayer capacitor 10-2 differs from the multilayer capacitor 10 described above in that the widths Wb2 and Wc2 of the lead portions 15a2 and 16a2 of the first and second inner conductor layers 15 and 16 constituting the independent capacitor portions are the same as those of the multilayer capacitor 10-2. It is larger than the widths Wb and Wc of the lead portions 15a and 16a of the capacitor 10 and all have the same value, and the lead portions 15a1 and 16a1 of the first and second inner conductor layers 15 and 16 constituting each independent capacitor portion. The inner edge intervals b1 and b2 are all equal and larger than zero, and the two lead portions 15a1 and 16a1 are partially opposed in the stacking direction. Since other configurations are the same as those of the multilayer capacitor 10 described above, description thereof is omitted.

  In this multilayer capacitor 10-2, the inner edge intervals b1, b2 of the lead portions 15a2, 16a2 of the first and second inner conductor layers 15, 16 constituting each independent capacitor portion are made larger than zero, and By making the two lead portions 15a1 and 16a1 partially face each other in the stacking direction, the length of the current path from the one polarity lead portion 15a2 to the other polarity lead portion 16a2 is further shortened. The magnetic field canceling action obtained by the current flowing in the reverse direction to the lead portions 15a2 and 16a2 with the one polarity lead portion 15a2 and the other polarity lead portion 16a2 being brought closer to each other can be further reduced. Thus, the ESL of the multilayer capacitor 10-2 can be further reduced. Since other functions and effects are the same as those of the multilayer capacitor 10 described above, description thereof is omitted.

1 is a perspective view of a multilayer capacitor showing a first embodiment of the present invention. FIG. 2 is a left side view of the multilayer capacitor illustrated in FIG. 1. FIG. 2 is a transverse cross-sectional view of the multilayer capacitor shown in FIG. 1. It is a perspective view which shows the layer structure of the main body shown in FIG. FIG. 4 is a left side view of the multilayer capacitor corresponding to FIG. 2, showing a second embodiment of the present invention. FIG. 6 is a cross-sectional view corresponding to FIG. 3 of the multilayer capacitor shown in FIG. 5. FIG. 6 is a left side view of the multilayer capacitor corresponding to FIG. 2, showing a third embodiment of the present invention. FIG. 8 is a transverse sectional view corresponding to FIG. 3 of the multilayer capacitor shown in FIG. 7.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 10-1, 10-2 ... Multilayer capacitor, 11 ... Main body, 12 ... 1st external electrode, 13 ... 2nd external electrode, 14 ... Insulation coating | cover part, 15 ... 1st internal conductor layer, 15a, 15a1, 15a2 ... Leader, 16... Second internal conductor layer, 16a, 16a1, 16a2... Leader, DL... Dielectric layer, b1, b2.

Claims (8)

A multilayer capacitor in which a first external electrode having one polarity and a second external electrode having the other polarity are alternately provided in a non-contact manner on a side surface of a rectangular parallelepiped body,
The main body alternately includes a plurality of first inner conductor layers arranged in a non-contact manner on the same plane, and the same number of first inner conductor layers arranged in a non-contact manner on the same plane as the second inner conductor layers via a dielectric layer. A plurality of independent capacitor portions are configured by the first and second internal electrode layers arranged in the stacking direction via the dielectric layer, and having a structure integrated by stacking,
The first and second inner conductor layers of each independent capacitor portion have one lead portion at different positions on the same side edge, and the lead portion of the first inner conductor layer of each independent capacitor portion serves as the first outer electrode. Each connected, and the lead portion of the second inner conductor layer is connected to the second outer electrode adjacent to the first outer electrode,
The edge of the lead portion of the first and second inner conductor layers of each independent capacitor portion is the side surface of the main body between the first and second outer electrodes to which the lead portions of the first and second inner conductor layers are connected. It is partially exposed, and the edge exposed portion is covered with an insulating coating provided between the first and second external electrodes on the side surface of the main body.
A multilayer capacitor characterized by that. Two first external electrodes and two second external electrodes are provided on each side surface in the width direction of the main body,
The number of first internal conductor layers arranged in a non-contact manner on the same plane is 2, the number of second internal conductor layers arranged in a non-contact manner on the same plane is 2, and the number of independent capacitor portions is 2.
One lead-out portion is provided on each side edge in the width direction of the first and second inner conductor layers of each independent capacitor portion, and the lead-out portion on one side edge of the first inner conductor layer of each independent capacitor portion is the main body. The lead portion on the other side is connected to the first external electrode on the other side of the main body, and the lead on the one side edge of the second internal conductor layer of each independent capacitor portion is connected to the first outer electrode on the other side. The part is connected to the second external electrode on one side of the main body, and the lead-out part on the other side edge is connected to the second external electrode on the other side of the main body.
The multilayer capacitor according to claim 1. The lead portions of the first and second inner conductor layers of each independent capacitor portion have a rectangular shape, the interval between the inner edges of the lead portions of the first and second inner conductor layers is greater than zero, and both lead portions Are not facing each other in the stacking direction,
The multilayer capacitor according to claim 1 or 2, wherein The lead portions of the first and second inner conductor layers of each independent capacitor portion have a rectangular shape, and the inner edge interval of the lead portions of the first and second inner conductor layers is zero.
The multilayer capacitor according to claim 1 or 2, wherein The lead portions of the first and second inner conductor layers of each independent capacitor portion have a rectangular shape, the interval between the inner edges of the lead portions of the first and second inner conductor layers is greater than zero, and both lead portions Are partially facing in the stacking direction,
The multilayer capacitor according to claim 1 or 2, wherein The width of the lead portions of the first and second inner conductor layers of each independent capacitor portion is larger than the width of the first and second outer electrodes to which the lead portions of the first and second inner conductor layers are connected.
The multilayer capacitor according to any one of claims 3 to 5, wherein: The insulating coating is made of the same material as the dielectric layer that makes up the body.
The multilayer capacitor according to any one of claims 1 to 6, wherein the multilayer capacitor is characterized by that. The thickness of the insulating coating is smaller than the thickness of the first and second external electrodes;
The multilayer capacitor according to any one of claims 1 to 7, wherein the multilayer capacitor is characterized by the above.

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