JP2012033544A - Device including plural capacitor elements - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device including a plurality of capacitor elements, the device having a low ESL.SOLUTION: A device 1 comprises a plurality of stacked capacitor elements 21, 22, and 23, each including a plate-like conductive substrate 33 and electrode layers 36 formed by laminating a layer having a dielectric property on both surfaces of the substrate 33 so as to sandwich the substrate 33 therebetween, and connected with each other via a through-electrode 38 penetrating the substrate 33. In the device, the edge of one surface of the substrate 33 is exposed to be an anode 31 and the electrode layers 36 constitutes a cathode 32, and the second capacitor element 22 and third capacitor element 23 are stacked on the first capacitor element 21, and each capacitor element has the substrates 33 having an area different from each other.

Description

  The present invention relates to a capacitor employed in various electronic devices and a mounting device incorporating the capacitor.

  Patent Document 1 discloses a capacitor element substrate in which an anode portion is formed on one side of a flat valve action metal plate having a dielectric oxide film layer on the surface, and a cathode portion comprising a solid electrolyte layer and a cathode lead layer is formed on the other side. In a multilayer solid electrolytic capacitor in which a plurality of layers are stacked, it is described that the anode portions of the capacitor element substrate are alternately stacked so that the anode portions face each other centering on the cathode portion.

JP 2007-1116064 A

  A capacitor that is one of electronic components is required to be able to have a low impedance in a wide frequency band in order to obtain a performance excellent in noise removal and transient response as the frequency of electronic equipment increases.

  One embodiment of the present invention is a device having a plurality of stacked capacitor elements. Each capacitor element is an electrode layer formed by sandwiching at least a plate-like conductive base and layers having dielectric properties on both sides of the base, and is provided in a hole penetrating the base and / or a side surface of the base. An electrode layer electrically connected by the connection layer formed, and at least a part of an end of one surface (for example, the surface or the upper surface) of the substrate is exposed to become a first connection electrode portion, and at least the electrode layer A part is a second connection electrode portion. Further, the plurality of capacitor elements are a first capacitor element and a second capacitor element stacked on the first capacitor element, and the area of the base is smaller than the area of the base of the first capacitor element. 2 capacitor elements.

  This device is a low ESR (equivalent series resistance) capacitor element having the same basic configuration and having an electrode layer connected by a hole penetrating the substrate and / or a connection layer provided on a side surface of the substrate. The first and second capacitor elements having different capacitances and different capacitances are included, and each capacitor element includes a first connection electrode portion. Therefore, a device including a plurality of different capacitance components (capacitor components) can be provided, and the impedance can be lowered in a wide frequency band. Further, the electrode layers are electrically connected by stacking these first and second capacitor elements. For this reason, it is possible to provide a device or a capacitor device having a plurality of different capacitor components with a simple configuration.

  The second capacitor element is preferably stacked in a portion excluding the first connection electrode portion on one surface of the base of the first capacitor element. This is because when the device is used, the first connection electrode portion of the first capacitor element is easily connected to the connection terminal portion by a bonding wire or the like.

  It is desirable that the first connection electrode portion of the first capacitor element and the first connection electrode portion of the second capacitor element appear on the same side (same end side) of the device. Since a plurality of connection electrode portions appear on the same side, it is easy to connect a bonding wire or the like when making a device.

  Furthermore, it is preferable that an insulating layer is provided on a portion facing the first connection electrode portion on the other surface (for example, the back surface or the bottom surface) of the base. The first connection electrode portion appears only on one surface, and the opposite surface is insulated. Therefore, the bases can be insulated from each other by stacking the first and second capacitor elements so that the other surface of the second capacitor element is in contact with one surface of the first capacitor element. Can be electrically connected.

  The first connection electrode portion of the first capacitor element and the first connection electrode portion of the second capacitor element may appear on the opposite side (different end side) of the device. When a device is used, it is easy to change the direction of current flowing through different capacitor components, or to arrange a connection terminal portion so as to be a through type, and to further reduce ESL (equivalent series inductance).

  It is desirable that one surface of the base body of the first capacitor element is rectangular, and one end in the longitudinal direction of the one surface of the base body appears as the first connection electrode portion. Thereby, it is easy to ensure a compact and large capacitance.

  The typical first and second capacitor elements are solid electrolytic capacitor elements. In the solid electrolytic capacitor element, the base is a valve action base having a valve action, and the electrode layer is laminated via a layer having a dielectric property including a dielectric oxide film and a solid electrolyte layer.

  In the device, the thickness of the dielectric oxide film of the first capacitor element may be different from the thickness of the dielectric oxide film of the second capacitor element. Capacitance can be further controlled by changing the thickness of the dielectric oxide film, which is a dielectric layer.

  Another aspect of the present invention includes a plurality of the capacitor elements described above, a first connection terminal portion electrically connected to the first connection electrode portion of the first capacitor element, and a second A second connection terminal portion electrically connected to the first connection electrode portion of the capacitor element and a reference voltage electrically connected to the electrode layer of the first capacitor element, for example, a ground voltage A device having a connection terminal portion. A device for surface mounting having different capacitor components and low impedance in a wide frequency band can be provided.

  The device includes a first bonding wire that connects the first connection electrode portion and the first connection terminal portion of the first capacitor element, and the first connection electrode portion and the second connection of the second capacitor element. It is desirable to further have a second bonding wire that connects the terminal portion. Further, the first connection terminal portion and the second connection terminal portion may be electrically connected.

  The device has a rectangular (cubic or cuboid) package that accommodates a plurality of capacitor elements, and the first connection terminal portion, the second connection terminal portion, and the reference voltage connection terminal portion are opposite to each other of the package. It is desirable to appear on the two sides. In particular, one surface of the base of the first capacitor element is rectangular, the package is rectangular (cuboid), and one end in the longitudinal direction of one surface of the base of the first capacitor element is the first connection. It is desirable that the first connection terminal portion, the second connection terminal portion, and the reference voltage connection terminal portion appear as two electrode sides extending in the longitudinal direction of the package.

  By adopting an arrangement in which one end in the longitudinal direction of one surface of the base of the first capacitor element is the first connection electrode part, the area covered by the electrode layer of the base is expanded and the capacitance is increased. Can be bigger. At the same time, since the current flows in the short direction in the direction orthogonal to the longitudinal direction of the first capacitor element, the current path can be made thick and short. Therefore, it is possible to provide a device having a large capacity and low ESR and low ESL. The first connection terminal portion and the second connection terminal portion may be disposed on opposite sides, and the direction of the current flowing through the first capacitor element and the second capacitor element can be changed. Devices can be provided.

  In addition, the first connection terminal portion and the second connection terminal portion may appear in the first direction of the package, and the reference voltage connection terminal portion may appear in the second direction orthogonal to the first direction. . A low ESL feedthrough device that includes different capacitor components can be provided.

  Another aspect of the present invention is a printed wiring board on which the above device is mounted, and an electronic apparatus having the printed wiring board.

The perspective view which shows the outline | summary of a device. The perspective view which shows a device in the state which remove | excluded mold resin. Fig. 3 is a developed view of the device on a lead frame and capacitor element. The top view which shows a device in the state except mold resin. The bottom view which shows a device in the state which excluded mold resin. The rear view which shows a device in the state except mold resin. Sectional drawing which shows the structure of a capacitor | condenser element. Sectional drawing which shows a mode that the capacitor | condenser element was piled up. The top view which shows a part of printed wiring board carrying a device. The block diagram which shows the circuit containing a device. 11A shows an impedance curve of each capacitance of the device, FIG. 11B shows a synthesized impedance curve of the device, and FIG. 11C shows a comparison with the impedance curve according to the conventional method. 12A shows a conventional connection method, FIG. 12B shows an impedance curve of each capacitor, and FIG. 12C shows a synthesized impedance curve. FIG. 13A is a block diagram illustrating different application examples of the device, and FIG. 13B is a block diagram illustrating still another application example of the device. 14A and 14B are diagrams for explaining the arrangement of capacitor elements, in which FIG. 14A is an example of the prior art, FIG. 14B is an example of a different arrangement, and FIG. 14C is an example of a further different arrangement. The top view which shows a different device in the state except mold resin. The side view which shows the device of FIG. 15 in the state which excluded mold resin. Furthermore, the top view which shows a different device in the state except mold resin. The bottom view which shows the device of FIG. 17 in the state which remove | excluded mold resin. The side view which shows the device of FIG. 17 in the state which remove | excluded mold resin. Sectional drawing which shows the structure of a different capacitor | condenser element.

  FIG. 1 shows an example of a device including a capacitor according to the present invention. The device 1 includes a capacitor 20, a lead frame 10 connected to the capacitor 20, and a package 50 that contains the capacitor 20 and a part of the lead frame 10 is exposed on the surface. The package 50 is made of an exterior resin (mold resin) 59 that is molded so as to be square or rectangular (rectangular) as a whole in a state in which the capacitor 20 is accommodated, and forms the external appearance of the capacitor device 1 for surface mounting. is doing. Hereinafter, the longitudinal direction of the device 1 will be described as the direction X, and the lateral direction orthogonal to the longitudinal direction X will be described as the direction Y.

  FIG. 2 shows a state where the mold resin 59 of the device 1 is removed. FIG. 3 shows a state where the lead frame 10 and the capacitor 20 are separated. 4, 5, and 6 show a plan view, a side view, and a bottom view of the device 1 with the mold resin 59 removed. As the material of the lead frame 10 of the device 1, a material excellent in mechanical strength, electrical conductivity, thermal conductivity, corrosion resistance, etc., such as a copper-based material and an iron-based material is used. The lead frame 10 includes first to third anode terminal portions (anode leads) 11 to 13 and first to third cathode terminal portions (cathode leads, terminal portions for ground voltage) 15 to 17.

  Capacitor 20 includes a first capacitor element 21, and a second capacitor element 22 and a third capacitor element 23 arranged to be stacked on first capacitor element 21. These capacitor elements 21, 22 and 23 are solid electrolytic capacitors (solid electrolytic capacitor elements), and have a basic configuration in common, and the areas of the base bodies 33 (typically the area of the surface 33a) S1, S2 and S3 is different. In this capacitor 20, the area S1 of the base 33 of the first capacitor element 21 is the largest, and the area S2 of the base 33 of the second capacitor element 22 and the area S3 of the base 33 of the third capacitor element 23 decrease in this order. It has become.

  FIG. 7 shows the configuration of the first capacitor element 21 as a representative in section. The capacitor element 21 has a flat plate shape as a whole and has a plate-like or thin-film valve action base 33 cut into a rectangular shape. The valve action base 33 includes a first surface (one surface, front surface) 33a and a second surface (the other surface, back surface) 33b that have been made porous (enlarged) by etching or the like. In this example, the side facing the lead frame 10 is referred to as a second surface (back surface) 33b. These surfaces 33a and 33b may be turned upside down or may face left and right.

  On the surface (one surface) 33a of the substrate 33, a dielectric oxide film 34a, a solid electrolyte layer 35a, and an electrode layer 36a are laminated in this order. Similarly, a dielectric oxide film 34b, a solid electrolyte layer 35b, and an electrode layer 36b are sequentially laminated on the back surface (the other surface) 33b of the base 33. Examples of the valve action base 33 include an etched aluminum foil, a tantalum sintered body, a niobium sintered body, and a titanium sintered body. A capacitor element using an etched aluminum foil is suitable for the thin device 1 for surface mounting.

  The dielectric oxide films 34a and 34b are aluminum oxide formed on the surface of the base 33 if it is an etched aluminum foil. The solid electrolyte layers 35a and 35b can be formed by laminating conductive polymers such as polypyrrole, polythiophene, and polyaniline on the dielectric oxide films 34a and 34b, respectively, by electrolytic polymerization, chemical polymerization, or the like. An example of the electrode layers 36a and 36b is a conductive paste laminated on the solid electrolyte layers 35a and 35b, respectively. The electrode layers 36 a and 36 b constitute a cathode, and a part thereof becomes a connection electrode portion (second connection electrode portion, cathode) 32. Layers having dielectric properties formed between the substrate 33 and the electrode layers 36a and 36b or for exerting them satisfactorily are not limited to the dielectric oxide films 34a and 34b and the solid electrolyte layers 35a and 35b. In order to reduce resistance, it may include a solid electrolyte layer 35a, a highly conductive graphite layer laminated between the electrode layers 36a, and the like.

  Note that the electrode layers 36a and 36b described as functioning as cathodes in this specification are apparent cathodes, and the solid electrolyte layers 35a and 35b play a role of functioning as true cathodes. Therefore, the dielectric oxide films 34a and 34b are layers having dielectric characteristics. The same applies to the following. Hereinafter, the electrode layers 36 a and 36 b are referred to as the cathode 32.

  Further, a first insulating layer 39a is formed on the surface 33a of the base 33 to cover the entire periphery of the peripheral edge 36c of the electrode layer 36a. Further, a second insulating layer 39b is formed on the back surface 33b of the base body 33 so as to cover the entire periphery of the peripheral edge 36c of the electrode layer 36b. One end (edge) 31 in the longitudinal direction X of the surface 33a of the base body 33 appears (exposes) on the outer peripheral side of the first insulating layer 39a, and the connection electrode portion of the capacitor element 21 (first connection electrode portion, anode) ) 31. An example of the insulating layers 39a and 39b is a film made of an insulating resin such as a polyimide resin or an epoxy resin. The insulating layer 39 b on the back surface 33 b extends to the back side of the anode 31 and forms an insulating layer 39 c that covers the back side of the anode 31. The side surface of the base 33 is also covered with an insulating layer 39d.

  The capacitor element 21 further includes a through hole (through hole) 37 that penetrates the valve action base 33. A dielectric oxide film 34c and a solid electrolyte layer 35c are sequentially laminated on the inner peripheral surface 37a of these through holes 37 from the side in contact with the valve action base 33. Further, the through holes 37 are electrically conductive such as silver paste. The through electrode 38 is formed by filling the paste. Even on the inner peripheral surface 37a of the through-hole 37, the solid electrolyte layer 35c can be formed together with the surface of the substrate 33 by a method such as electrolytic polymerization, and can contribute to the capacitance of the capacitor. In addition, the through electrode 38 functions as a connection layer that electrically connects the electrode layers 36a and 36b.

  The through electrode 38 provided in the capacitor elements 21 to 23 is not limited to 1 or 2, but may be 3 or more. By providing the through electrode 38, the current path between the anode (first connection electrode portion) 31 and the cathode (second connection electrode portion) 32 can be shortened. For this reason, capacitor elements 21 to 23 having low ESR and low ESL can be provided.

  The thicknesses of the dielectric oxide films 34a and 34b included in the capacitor elements 21 to 23 are different in each of the capacitor elements 21 to 23. The thickness t1 of the dielectric oxide films 34a and 34b of the first capacitor element 21 having the largest area is, for example, 4 nm, and the thickness t2 of the dielectric oxide films 34a and 34b of the second capacitor element 22 is, for example, The thickness t3 of the dielectric oxide films 34a and 34b of the third capacitor element 23 is, for example, 70 nm. The thickness of the capacitor element is not limited to these. Such capacitor elements 21 to 23 having different thicknesses can be easily manufactured by changing the voltage (formation voltage of the substrate) when the dielectric oxide films 34a and 34b are formed.

  Capacitance of the capacitor elements 21 to 23 can be changed by changing the thicknesses of the dielectric oxide films 34a and 34b of the capacitor elements 21 to 23. The capacitance of the capacitor element is approximately proportional to the areas S1 to S3 and inversely proportional to the thicknesses t1 to t3 of the dielectric oxide films 34a and 34b. Therefore, a plurality of capacitor elements having a capacitance difference of about 1: several hundreds or more can be incorporated in one device 1. For example, a device 1 including a first capacitor element 21 having a capacity of 200 μF, a second capacitor element 22 having a capacity of 40 μF, and a third capacitor element 23 having a capacity of 1 μF can be provided.

  Furthermore, the withstand voltage (rated voltage) of the capacitor elements 21 to 23 can be changed by changing the dielectric oxide films 34a and 34b of the capacitor elements 21 to 23. The rated voltage of the capacitor element is approximately inversely proportional to the thicknesses t1 to t3 of the dielectric oxide films 34a and 34b. Therefore, a plurality of capacitor elements having a rated voltage difference of about 1: several tens or more can be incorporated into one device 1. For example, the device 1 including the first capacitor element 21 having the rated voltage of 2V, the second capacitor element 22 having the rated voltage of 6.3V, and the third capacitor element 23 having the rated voltage of 25V can be provided.

  FIG. 8 is a cross-sectional view illustrating a state where the capacitor elements 21 to 23 are stacked. As described above, in the basic configuration of these capacitor elements 21, 22 and 23, the cathode 32 appears on the front surface 33a and the back surface 33b, and the cathode 32 is connected by the through electrode 38 and is connected to one end in the longitudinal direction. The anode 31 appears, and the periphery of the cathode 32 on the front surface 33a and the back surface 33b and the back surface of the anode 31 are covered with insulating layers 39a to 39d. For this reason, by stacking the capacitor elements 21, 22 and 23, the cathodes 32 of the respective elements 21 to 23 can be electrically connected directly or via a conductive paste or the like. ~ 23 can be connected in parallel. In the example shown in FIG. 8, the conductive paste 49 is sandwiched between the cathodes 32 and the cathodes are electrically connected.

  Furthermore, the areas S1, S2 and S3 of the surface 33a of the base 33 of the capacitor elements 21, 22 and 23 are different. For this reason, the capacitor elements 21 to 23 can be stacked so that the anodes 31 of the respective capacitor elements 21, 22 and 23 are not hidden by the capacitor elements 22 and 23 which overlap the upper side (surface 33a side). In this device 1, the first capacitor element 21 having the largest area determines the main dimensions of the device 1, and the longitudinal direction X of the first capacitor element 21 coincides with the longitudinal direction X of the device 1. Yes. On the first capacitor element 21, the second capacitor element 22 having the next largest area is a portion excluding the anode 31 of the first capacitor element 21, that is, the cathode of the surface 33 a of the first capacitor element 21. The cathode 32 is mounted on the 32 so as to overlap each other. Further, the third capacitor element 23 having the smallest area is aligned with the second capacitor element 22 on the cathode 32 of the surface 33 a of the first capacitor element 21, however, the longitudinal direction of the third capacitor element 23. Are stacked so as to be orthogonal to the longitudinal direction X of the first capacitor element 21. That is, the third capacitor element 23 is arranged such that its longitudinal direction is along the short direction Y of the device 1.

  The anode 31 of the first capacitor element 21 appears at one end in the longitudinal direction X of the device 1, and the anode 31 of the second capacitor element 22 is aligned with the anode 31 of the first capacitor element 21. It appears on the same side (same end side) of the device 1 at a position slightly retracted from one end in the longitudinal direction X of the device 1. Further, the anode 31 of the third capacitor element 23 appears at the end in the short direction Y on the opposite side (reverse side) of the longitudinal direction X from the anode 31 of the second capacitor element 22. Therefore, in the device 1, the three capacitor elements 21 to 23 are stacked so that each anode 31 can be accessed from above the device 1. By stacking the three capacitor elements 21 to 23, the cathode 32 on the back surface 33 b of the second and third capacitor elements 22 and 23 is in electrical contact with the cathode 32 on the surface 33 a of the first capacitor element 21. . In order to further ensure electrical contact, a conductive paste may be sandwiched between the cathodes 32 of these capacitor elements 21 to 23.

  On the other hand, the back surface 33b side of the anode 31 of each capacitor element 21 to 23 is covered with an insulating layer 39c. For this reason, even if the capacitor elements 21 to 23 are stacked, the anodes 31 of the capacitor elements 21 to 23 are not electrically connected to each other or to the anode 31 and the cathode 32. Therefore, by stacking the three capacitor elements 21 to 23, the capacitor 20 in which the cathode 32 is connected and the anode 31 is open can be formed.

  As shown in FIG. 2, in the device 1 (capacitor 20), the anode 31 of the first capacitor element 21 is a conductive metal wire (first bonding wire) 41 such as a gold wire, a copper wire, or an aluminum wire. Thus, the lead frame 10 is electrically connected to the first anode terminal portion (first connection terminal portion, anode lead) 11. Further, the anode 31 of the second capacitor element 22 is electrically connected to the second anode terminal portion (second connection terminal portion, anode lead) 12 of the lead frame 10 by the second bonding wire 42. Further, the anode 31 of the third capacitor element 23 is electrically connected to the third anode terminal portion (third connection terminal portion, anode lead) 13 of the lead frame 10 by the third bonding wire 43.

  On the other hand, the first to third cathode terminal portions (reference voltage connection terminal portions, cathode leads) 15 to 17 of the lead frame 10 are electrically and mechanically connected to the cathode 32 of the back surface 33 b of the first capacitor element 21. It is connected to the. The first to third cathode leads 15 to 17 are usually connected to the ground side (ground circuit) of the circuit and applied with a reference voltage (ground voltage).

  In the device 1, the capacitor elements 21 to 23, the bonding wires 41 to 43 and the lead frame 10 are covered with an exterior resin (mold resin) 59 and packaged. However, the externally connected portion of the lead frame 10 is not covered with the mold resin 59. An example of the mold resin 59 is a sealing resin such as an epoxy resin. The anode leads 11 to 13 and the cathode leads 15 to 17 of the lead frame 10 appear outside the package 50 made of mold resin. The ends of the leads 11 to 13 and 15 to 17 appearing outside the package 50 are bent downward (back side) along the package 50, and the device 1 is used as a surface mounting device mounted on a circuit board or the like. Is done.

  In this device 1, as shown in FIG. 6, the package 50 has a rectangular shape (a rectangular parallelepiped), and the anode leads 11 to 13 are formed side by side along one side 51 extending in the longitudinal direction X of the package 50. The cathode leads 15 to 17 are formed side by side on the other side 52 extending in the longitudinal direction X of the package 50. Therefore, the anode leads 11 to 13 and the cathode leads 15 to 17 appear on the two opposite sides 51 and 52 extending in the longitudinal direction X of the package 50.

  FIG. 9 schematically shows a part of a printed wiring board on which the device 1 including the capacitor 20 is mounted. FIG. 10 is a block diagram of a power supply circuit including the device 1. The printed wiring board (printed circuit board) 9 is, for example, a mother board of an electronic device such as a personal computer. A CPU 3 and a power supply block (not shown in FIG. 9) 2 are mounted on the printed wiring board 9, and the device 1 is connected in parallel between the ground circuit 5 and the power supply circuit 4 that connects the power supply block 2 to the CPU 3. It is connected. This device 1 functions as a decoupling capacitor or a bypass capacitor.

  Further, the device 1 includes three capacitor elements 21 to 23 having different surface areas S1, S2 and S3 of the base body 33 and connected in parallel. Since these capacitor elements 21 to 23 have different surface areas S1, S2 and S3, their capacitances (capacitor capacities) C1, C2 and C3 are almost proportional to the surface areas S1, S2 and S3. Further, each of the capacitor elements 21 to 23 has the cathode 33 on the front surface 33a and the back surface 33b connected by the through electrode 38, the current path from the anode 31 to the cathode 32 is short, and the direction of current flow varies. . Accordingly, each capacitor element 21 to 23 has low ESR and low ESL. For this reason, the anode terminals (anode leads) 11, 12 and 13 of the device 1 are connected to the power supply circuit 4, and the cathode terminals 15, 16 and 17 are connected to the ground circuit 5. Different elements 21 to 23 are connected in parallel. Therefore, by adopting the device 1 in the power supply circuit, the impedance can be lowered in a wide frequency band, and noise in a wide range of frequencies can be removed.

  FIGS. 11A to 11C schematically show how low impedance is realized in a wide frequency band. The impedance curve 61 of the capacitance C1 of the first capacitor element 21 having a large capacity, the impedance curve 62 of the capacity C2 of the second capacitor element 22 having a middle capacity, and a third capacitor having a small capacity as shown in FIG. The impedance curve 63 of the capacitor C3 of the capacitor element 23 is synthesized, and an impedance curve 64 having a low (broad) impedance in a wide frequency band as shown in FIG. 11B can be reproduced.

  As shown in FIG. 12A, conventionally, in order to obtain such characteristics, it has been necessary to connect a plurality of capacitor devices 29a to 29c having different capacities in parallel. The plurality of capacitor devices 29a to 29c having different capacities have different sizes, and are a combination of capacitors of different types (for example, tantalum capacitors, ceramic capacitors, etc.). For this reason, not only the capacities differ, but also the ESR and ESL differ, and the ESLs do not match as shown in FIG. Accordingly, as shown in FIG. 12C, the synthesized impedance curve 69 has a plurality of inflection points. Electrically, LC resonance will occur.

  On the other hand, as shown in FIG. 11B, since the device 1 houses the capacitor elements 21 to 23 having different capacitance characteristics in one package, other characteristics excluding the capacitance characteristics, that is, ESL and ESR are the same. become. Therefore, as shown in comparison with FIG. 11C, an impedance curve 64 showing a low impedance characteristic with less characteristic change over a wider frequency range than the impedance curve 69 is obtained. Therefore, it is possible to provide the device 1 that exhibits flat impedance characteristics with less occurrence of LC resonance.

  Furthermore, since a single device 1 can provide a device having a plurality of capacitance characteristics, the space required for mounting the device to obtain a plurality of capacitance characteristics can be reduced, and a conventional application in which a large number of capacitors are mounted is one. It can be replaced by one or a few devices 1. Therefore, it is suitable for electronic devices such as information processing terminals such as notebook personal computers, which are becoming more compact, and portable information processing terminals such as mobile phones and PDAs.

  FIG. 13 shows several examples of different uses of the device 1. FIG. 13A shows that a function as a decoupling capacitor or a bypass capacitor can be added to the power supply system of the semiconductor 3 a having a plurality of voltage lines with one or a few devices 1. In an electronic device or a printed wiring board provided with a plurality of power supply blocks (switching power supplies) 2a, 2b and 2c, each capacitor element 21 of the device 1 is connected to each of a plurality of voltage lines (voltage circuits) 4a, 4b and 4c. 22 and 23 can be connected. As described above, the device 1 includes a plurality of capacitor elements 21 to 23 having different rated voltages. Therefore, the device 1 can cope with a plurality of voltages. Moreover, even if it is the same voltage line, when there exists a line which supplies several electric power, the device 1 can adapt to each electric power line.

  FIG. 13B shows an example applied to a π-type filter. The existing π-type filter including the capacitor element has a drawback that the circuit adaptability is poor because the coil component (inductor) is arranged in the device. On the other hand, in the case of the device 1, the coil components L1, L2, and L3 arranged in series can be made an open system that can be mounted on a printed wiring board or the like. Therefore, the coil components L1, L2, and L3 can be freely arranged by the wiring width, wiring length, or inductor device of the circuit pattern, and the π-type filter 6 suitable for the circuit to be mounted can be configured.

  Further, in the device 1, the anode (first connection electrode portion) 31 of the large-capacity capacitor element 21 is disposed at the end in the longitudinal direction X, and the first to third anode terminals (first to third connections) are arranged. Terminal portions) 11 to 13 and first to third cathode terminals (first to third connection terminals for reference voltage) 15 to 17 are extended to two sides 51 and 52 extending in the longitudinal direction X of the package 50. Is arranged. Therefore, in the device 1, the direction X of the cathode 32 with respect to the anode 31 of the large capacity capacitor element 21 (opposite direction, longitudinal direction) X, and the direction of the cathode terminals 15 to 17 with respect to the anode terminals 11 to 13 (opposite direction, (Short direction) Y is orthogonal. For this reason, in the device 1, since the short direction Y becomes a current path, ESL and ESR can be further reduced, and the extending direction of the cathode 32 can be set to the longitudinal direction X, so that the capacity of the capacitor element 21 can be increased.

  FIG. 14 schematically shows a comparison with a device including a conventional solid electrolytic capacitor element. FIG. 14A shows an example of a conventional solid electrolytic capacitor element 75. The element 75 is entirely rectangular (a rectangular parallelepiped), the anode 71 appears at one end in the longitudinal direction X, and the anode terminal 73 and the cathode 74 face each other in the longitudinal direction X. Therefore, the length (L dimension) in the longitudinal direction X of the element 75 can be used to arrange the cathode 72, and a large area of the cathode 72 can be secured. For this reason, a large-capacity capacitor element 75 can be obtained. The anode terminal 73 and the cathode terminal 74 are also arranged opposite to the longitudinal direction X. The anode 71 and the anode terminal 73 of the element 75 are electrically connected by a lead or a bonding wire 79, and the cathode 72 and the cathode terminal 74 are electrically connected directly or by a conductive paste. In the element 75, the longitudinal direction X of the element 75 is a current path.

  One method of reducing the ESL of the element 75 is to shorten a loop length in which a current loops when connected. Therefore, the current path is preferably changed from the longitudinal direction X to the lateral direction Y. In the solid electrolytic capacitor element 76 shown in FIG. 14B, the anode 71 and the cathode 72, and the anode terminal 73 and the cathode terminal 74 are both arranged in the short direction Y (so as to face each other). In the element 76, the current path is in the short direction Y, and the distance (loop length) through which the current flows is shortened from the L dimension of the element 76 to the W dimension. Therefore, a low ESL device can be provided. However, the distance that can be used to arrange the cathode 72 and the dielectric layer becomes the W dimension in the lateral direction Y, and the area of the cathode 72 and the dielectric layer is reduced. Therefore, the capacitor capacity tends to decrease, and it is difficult to reduce the ESR of the device.

  In the solid electrolytic capacitor element 77 shown in FIG. 14C, the anode terminal 73 and the cathode terminal 74 are arranged in the short direction Y (so as to face each other), and the anode 71 and the cathode 72 are arranged in the longitudinal direction X (as opposed to each other). To arrange). In this element 77, the current path is in the short direction Y, and the distance (loop length) through which the current flows is shortened from the L dimension of the element 77 to the W dimension. Therefore, ESL can be reduced. Further, the distance that can be used to arrange the cathode 72 and the dielectric layer becomes the L dimension in the longitudinal direction X, and the areas of the cathode 72 and the dielectric layer can be enlarged. Therefore, the capacitance of the capacitor can be increased, and a low ESR can be realized. As described above, only the connection direction of the solid electrolytic capacitor is changed from the longitudinal direction X to the short direction Y, and the connection direction is reversed from the L dimension direction X to the W dimension direction Y, thereby further reducing ESL and ESR. Can provide a device.

  15 and 16 show examples of different devices. FIG. 15 is a plan view showing the device 1a with the package 50 omitted, and FIG. 16 is a side view showing the device 1a with the package 50 omitted. The basic configuration of the device 1 a is the same as that of the device 1 described above, and includes a capacitor 20 and a lead frame 10. The capacitor 20 includes three capacitor elements 21 to 23. On the first capacitor element 21 having a large capacity, a second capacitor element 22 having a medium capacity and a capacitor element 23 having a small capacity are arranged in parallel (the direction of the anode 31). Is a multilayer type capacitor device arranged so as to overlap each other. Also in this device 1a, the second capacitor element 22 and the third capacitor element 23 are stacked in a portion excluding the anode 31 of the lower-capacity first capacitor element 21.

  On the other hand, in this device 1a, the anode 31 of the second capacitor element 22 having a medium capacity is different from the anode 31 of the first capacitor element 21 having a larger capacity in the longitudinal direction X (the opposite side, the opposite side). ). Further, the second anode terminal 12 is disposed on the opposite side 52 of the package 50 with respect to the other anode terminals 11 and 13, and the second cathode terminal 16 is disposed with respect to the other cathode terminals 15 and 17. It is arranged on the opposite side 51 of the package 50. Therefore, the current flowing through the device 1a is reversed between the first terminals (terminals 11 and 15), between the third terminals (terminals 13 and 17), and between the second terminals (terminals 12 and 16). To do. Therefore, the direction of the magnetic field generated by the current flowing through the device 1a is reversed, and a device with lower ESL can be provided.

  17 to 19 show further examples of different devices. 17 is a plan view showing the device 1b with the package 50 omitted, and FIG. 18 is a bottom view showing the device 1b with the package 50 omitted (viewed from the side opposite to the plan view). 19 is a side view showing the device 1b with the package 50 omitted. The device 1b also has a capacitor 20 and a lead frame 10. Capacitor 20 includes four capacitor elements 21 to 24 stacked one above the other. The configuration of each capacitor element 21 to 24 is the same as that of the capacitor element 21 described above. The area of the base 33 of each capacitor element 21 to 24 is different, and the capacitance (capacitor (capacitor) of each capacitor element 21 to 24 is different. Capacity) is different.

  In the device 1b, a medium-capacitance capacitor element 22 is stacked on the upper side (front side) 33a of the large-capacity capacitor element 21 so that the anode 31 appears on the opposite side in the longitudinal direction X. Further, capacitor elements 23 and 24 having a small capacity and different capacities are stacked in parallel on the lower side (back side) 33b of the large capacity capacitor element 21 with the lead frame 10 interposed therebetween. The anodes 31 of the capacitor elements 23 and 24 appear on the opposite side in the longitudinal direction X.

  The lead frame 10 of the device 1b includes first to fourth anode leads (anode terminals) 11 to 14 arranged so as to appear on two sides 51 and 52 along the longitudinal direction X of the package 50, and a short side. A cathode lead 15 arranged so as to appear on two sides 53 and 54 along the direction Y. The cathode lead 15 is disposed so as to penetrate the package 50 in the longitudinal direction X. The cathode 32 of the first capacitor element 21 disposed on the front and back of the cathode lead 15, the third and fourth capacitor elements 23, and It is connected to 24 cathodes 32 directly or through a conductive paste. The cathode 32 of the second capacitor element 22 is electrically connected to the cathode lead 15 via the cathode 32 of the stacked first capacitor element 21, and the first to fourth capacitor elements 21 to 24 are connected. The cathode 32 is electrically connected to the cathode lead 15 in parallel.

  On the other hand, the anodes 31 of the first to fourth capacitor elements 21 to 24 are first to fourth anode leads appearing on two sides 51 and 52 along the longitudinal direction X by bonding wires 41 to 44, respectively. 11 to 14 are connected. Therefore, this device 1b includes four capacitor elements 21 to 24 having different capacities and connected in parallel. Further, the four anode terminals 11 to 14 connected to the anodes 31 of these four capacitor elements 21 to 24 appear on the two sides 51 and 52 along the longitudinal direction X of the package 50, and the cathodes of the capacitor elements 21 to 24. Ends (cathode terminals) 15 a and 15 b of the cathode lead 15 connected to 32 appear on two sides 53 and 54 along the short direction Y of the package 50. Therefore, in the device 1b, the direction in which the anode terminals 11 to 14 appear (first direction) and the direction in which the cathode terminals 15a and 15b appear (second direction) are orthogonal to each other, so-called through-type. It is a capacitor device.

  In the feedthrough type capacitor device 1b, the directions of the currents flowing between the terminals are orthogonal and reverse. For this reason, a magnetic field is canceled and ESL can be further reduced. Further, the device 1b includes capacitor elements 21 to 24 having four different capacities, and can be used as a capacitor device having a low impedance in a wide frequency band by connecting the anode terminals 11 to 14 in parallel. It becomes.

  FIG. 20 shows different examples of capacitor elements that can constitute the capacitor devices 1, 1a, and 1b described above. The capacitor element 21a is also laminated on the base 33, and on the front surface (upper surface) 33a and back surface (lower surface) 33b with layers (dielectric oxide coatings) 34a and 34b having dielectric properties interposed therebetween, and functions as a true cathode. It has electrolyte layers 35a and 35b. The electrode layers 36a and 36b functioning as the electrically connectable cathode 32 are stacked on the solid electrolyte layers 35a and 35b. Further, one end of the base body 33 is exposed to constitute the anode 31. Further, in this capacitor element 21a, the dielectric oxide film 34d, the solid electrolyte layer 35d, and the electrode layer 36d are also laminated on the side surface 33d of the base 33, and the electrode layer 36a on the front surface 33a and the electrode layer 36b on the back surface 33b. Are electrically connected.

  In the capacitor element 21a, upper and lower electrodes (cathodes) 32 are electrically connected by an electrode layer 36d formed on the side surface 33d of the base 33. The capacitor element 21a may include a through electrode 38 in addition to the side electrode layer 36d. In the case of the capacitor element 21a having the cathode 32 electrically connected to the upper surface 33a and the lower surface 33b of the base body 33, the cathode 32 is electrically connected by stacking (stacking) a plurality of capacitor elements vertically. Is possible. Then, by stacking capacitor elements having different surface areas on the upper surface 33a and / or the lower surface 33b of the base body 33, the anodes 31 of the respective capacitor elements 21a can be exposed so that they can be accessed from the stacked direction. By the method, the anode of each capacitor element 21a can be electrically connected to a connecting member such as a lead frame or a substrate.

  Furthermore, by stacking the capacitor elements 21a having different surface areas on the upper surface 33a and / or the lower surface 33b of the base body 33, it becomes possible to provide a device including capacitor elements having different capacitor capacities and the like, and a low ESL capacitor over a wide frequency band. Can provide a device. Further, in the capacitor element 21a, the side surface of the back surface 33b of the anode 31 of the base body 33 is covered with an insulating layer 39c. For this reason, it is possible to prevent electrical contact between the base 33 or the anode 31 of the plurality of capacitor elements 21a by simply stacking the plurality of capacitor elements 21a up and down, and the cathodes 32 of the plurality of capacitor elements 21a are directly or It can be easily electrically connected by sandwiching the conductive paste.

  As described above, the capacitor devices 1, 1a and 1b described above are formed by sandwiching the dielectric layer between the base 33 whose one end is the anode 31 and the front surface (upper surface) 33a and the rear surface (lower surface) 33b. In addition, the capacitor element includes a plurality of capacitor elements that are stacked (stacked) with different areas of the front surface 33a and / or the back surface 33b of the base 33. Therefore, the capacitor devices 1, 1a and 1b include a plurality of capacitor elements having different capacities, and by connecting a plurality of capacitor elements having different capacities in parallel, the impedance can be lowered in a wide frequency band. A low ESL capacitor device can be provided.

  The capacitor devices 1, 1a, and 1b described above are some examples of the present invention, and the way of stacking a plurality of capacitor elements having different areas is not limited to the above-described embodiment. A device in which a plurality of capacitor elements are stacked in three or more layers may be used. Instead of a lead frame, a connection terminal portion (anode terminal and cathode) that can be electrically connected to a connection electrode portion (anode and cathode) of the capacitor element. It may be a device incorporating a substrate on which terminals are arranged. Further, instead of the bonding wire, a device incorporating a lead frame processed into a shape that can be directly connected to the anodes of a plurality of stacked capacitor elements may be used. Furthermore, a device incorporating a lead frame in which the anodes of a plurality of stacked capacitor elements are connected (short-circuited) may be used. Further, the device for surface mounting according to the present invention can be used not only in combination with a CPU but also in combination with other circuit elements.

DESCRIPTION OF SYMBOLS 1 Device for surface mounting 10 Lead frame 20 Capacitor, 21, 22, 23, 24 Capacitor element 31 Anode (1st connection electrode part), 32 Cathode (2nd connection electrode part)
33 Base

Claims (15)

A device having a plurality of capacitor elements stacked,
Each of the capacitor elements is a plate-like conductive base and an electrode layer formed by sandwiching at least a layer having dielectric properties on both sides of the base, and a hole penetrating the base and / or the base An electrode layer electrically connected by a connection layer provided on a side surface of the substrate, wherein at least a part of an end of one surface of the base body is exposed to become a first connection electrode portion, and at least the electrode layer Part is the second connection electrode part,
The plurality of capacitor elements are a first capacitor element and a second capacitor element stacked on the first capacitor element, wherein an area of the base is larger than an area of the base of the first capacitor element. A device comprising a small second capacitor element.   2. The device according to claim 1, wherein the second capacitor element is stacked on a portion of the one surface of the base of the first capacitor element excluding the first connection electrode portion.   3. The device according to claim 1, wherein an insulating layer is provided in a portion facing the first connection electrode portion on the other surface of the base body.   4. The device according to claim 3, wherein the first connection electrode portion of the first capacitor element and the first connection electrode portion of the second capacitor element appear on the same side of the device.   4. The device according to claim 3, wherein the first connection electrode portion of the first capacitor element and the first connection electrode portion of the second capacitor element appear on the opposite side of the device.   6. The first capacitor electrode according to claim 1, wherein the one surface of the base of the first capacitor element is rectangular, and one end in the longitudinal direction of the one surface of the base is the first connection electrode. Devices appearing as parts.   7. The method according to claim 1, wherein the base body is a valve action base body having a valve action, and the electrode layer includes a layer having a dielectric property including a dielectric oxide film and a solid electrolyte layer. Devices that are stacked.   8. The device according to claim 7, wherein the thickness of the dielectric oxide film of the first capacitor element is different from the thickness of the dielectric oxide film of the second capacitor element. In any of claims 1 to 8,
A first connection terminal portion electrically connected to the first connection electrode portion of the first capacitor element;
A second connection terminal portion electrically connected to the first connection electrode portion of the second capacitor element;
A device further comprising a reference voltage connection terminal portion electrically connected to the electrode layer of the first capacitor element.   10. The first connection of the second capacitor element according to claim 9, wherein the first bonding wire connecting the first connection electrode portion of the first capacitor element and the first connection terminal portion, and the first connection of the second capacitor element. A device further comprising: a second bonding wire that connects the electrode portion and the second connection terminal portion. In Claim 9 or 10, it has a square package that houses the plurality of capacitor elements,
The device in which the first connection terminal portion, the second connection terminal portion, and the reference voltage connection terminal portion appear on two opposite sides of the package.   12. The one surface of the base of the first capacitor element is a rectangle, the package is a rectangle, and one end in the longitudinal direction of the one surface of the base is the first connection. A device that appears as an electrode part, and wherein the first connection terminal part, the second connection terminal part, and the reference voltage connection terminal part appear on the two opposite sides extending in the longitudinal direction of the package . The package according to claim 9 or 10, wherein the package houses the plurality of capacitor elements.
The first connection terminal portion and the second connection terminal portion appear in a first direction of the package, and the reference voltage connection terminal portion appears in a second direction orthogonal to the first direction. Is the device.   A printed wiring board on which the device according to claim 9 is mounted.   An electronic device having the printed wiring board according to claim 14.

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