DE102005007582A1 - Capacitor with a low equivalent series resistor and capacitor arrangement - Google Patents

Abstract

The invention relates to a capacitor, for. B. Tantalum capacitor, which is characterized by a low ESR value at a large capacitance voltage product. The capacitor has a plurality of capacitors arranged in a housing (10), each having a rod-shaped anode body (201, 202). With the invention it is possible to provide a particularly flat capacitor with a large CV value and at the same time a low ESR value.

Description

Described is electrical capacitor. From the pamphlets DE 10057488 A1 and DE 20203300 A1 are z. B. tantalum or niobium capacitors with a housing and a capacitor element arranged therein known.

A to be solved Task is to provide a capacitor which at a large capacity voltage value has a low ESR value.

It is a capacitor with several in a housing, preferably side by side, indicated capacitor elements indicated, each having a rod-shaped anode body. Thereby manages a particularly flat capacitor with a large CV value and at the same time provide a low ESR value.

By a rod is meant a body in which the ratio of its length to its cross-sectional size is at least the factor 2 is. The use of a plurality of rod-shaped anode body instead of only one anode body in a capacitor housing has the advantage that thereby externally contactable surface of the anode body or the corresponding capacitance element is increased.

The anode body can in the direction transverse to its main axis z. B. a rectangular, in particular have a square cross-section. But the anode body can also zy linderförmig or be formed differently.

Out the interior of an anode body protrudes out an anode conductor, which is preferably selected as a wire. The anode conductor can also have the shape of a strip.

The Capacitor element has a dielectric disposed on the anode body Layer and arranged on this layer cathode layer on, which preferably as a cathode conductor of the capacitor element serves.

The in a common housing enclosed, preferably identically formed capacitor elements or anode body are preferably arranged in a row. In a variant are the anode body in several, one above the other arranged in rows.

Various arranged in the common housing Capacitor elements are preferably electrically interconnected inside the housing connected, for example, in a preferred variant in parallel interconnected with each other. This succeeds in the replacement series resistance (ESR value) and at the same time a high capacitance voltage value to achieve.

The Anodenableiter, the various, z. B. arranged in a row capacities are assigned, preferably by a single, from the casing led out Anode connection contacted. This contacting is preferably carried out in the case, but also outside respectively.

In a variant, the cathode layers are different, z. In a series of ordered capacities contacted by a common, led out of the housing cathode terminal. This contacting is preferably carried out in the housing.

Everyone Terminal has a running in the housing Area and one outside extending area (outer flap) on. Part of the outside extending area forms a preferably for surface mounting suitable external connection of the Component.

The in various rows arranged capacitor elements are in an advantageous variant in each case anode and cathode side with each other and with the corresponding connection by preferably strip Connecting elements conductively connected.

In a variant with arranged in several (eg three) rows Capacitor elements, the anode terminal contacts the first, preferably lowest row of anode bodies. The second series of anode bodies is anode side to the anode terminal by a first connecting element mechanically strong and electrically connected. The second and the third Row of anode bodies is mechanical with each other through a second connecting element firmly and electrically connected.

In In a further advantageous variant, it is possible to extend the housing Fold or angle the section of the anode connection in such a way that several rows of the capacitor elements on the anode side by a single anode connection to be contacted.

Advantageous is an arrangement of several capacitors described above in a stack. The superposed capacitors are z. B. firmly connected to each other by means of an adhesive. Each capacitor has its own housing and own led out of the housing outlets (cathode connection, anode connection) on. In the housing of the respective capacitor, a plurality of capacitor elements are arranged side by side, each having a rod-shaped anode body.

Two Capacitors of the capacitor arrangement are interconnected by means the corresponding terminals z. B. by soldering or welding mechanically strong and electrically connected.

in the The following are capacitors based on embodiments and the associated figures explained in more detail. The Figures show schematic and not true to scale representations various embodiments. Same or equivalent parts are designated by the same reference numerals. It show schematically

1 a front perspective view of a capacitor having a plurality of rod-shaped anode bodies whose anode leads represent wires;

2 the capacitor according to 1 respectively. 3A in cross-section;

3A a detail of a front perspective view or the construction of a capacitor whose anode body strip-shaped Anodenableiter, from above;

3B a front perspective view of the capacitor according to 3A from underneath;

4A a partial front perspective view or the construction of a capacitor with a plurality of superimposed rows of capacitor elements;

4B the capacitor according to 4A in cross section (first variant for connecting rows of the capacitor elements with each other);

4C the capacitor according to 4A in cross section (second variant for connecting rows of the capacitor elements with each other);

5A a front perspective view and the construction of a capacitor arrangement with a plurality of capacitors, each according to 1 are trained;

5B a further front perspective view of the capacitor assembly according to 5A ;

6 . 7 in each case a variant of the capacitor arrangement according to 5A and 5B in schematic cross section.

In 1 an exemplary capacitor is shown. The capacitor has a housing 10 and a plurality of rows of capacitor elements arranged side by side in this housing. The housing 10 is preferably made of a plastic. Each capacitor element corresponds to a separate anode body 201 . 202 and 203 , The anode body 201 . 202 . 203 is, for example, a porous sintered body of tantalum powder. From the inside of the anode body is an anode conductor 21 led out. The anode conductor 21 is fixed with an anode connection 11 connected to the capacitor.

The capacitor elements arranged in a row are in preferred embodiments on the one hand with a common first terminal, preferably anode terminal 11 and on the other hand with a common second connection, preferably cathode connection 12 of the capacitor electrically and mechanically firmly connected. In the case of a plurality of rows of capacitor elements enclosed in a common housing, the capacitor elements of a row are connected to the anode or cathode connection led out of the housing via a connection element (eg connecting pieces) 41 . 42 in 4B ) firmly connected.

On the outer and inner surface of the anode body is an in 2 schematically shown dielectric layer 23 arranged. On the shift 23 is an electrically conductive cathode layer 22 arranged, whose outer part with a cathode connection 12 of the capacitor is firmly connected.

Every connection 11 . 12 of the capacitor is a corresponding to the course of the housing angled metal strip. The connection 11 respectively. 12 runs z. B. outside along a side surface of the housing 10 and is thereby used to form a surface-mountable external connection 11a respectively. 12a z. B. angled below the housing bottom in the direction of the body pointing direction. The external connections 11a respectively. 12a are located on the bottom of the case.

The anode body associated with the various capacitor elements 201 . 202 and 203 are arranged in a row in this example, so that the Anodenableiter 21 the capacitor elements arranged in a row are brought to a plane. This makes it possible, all anode arrester with a single anode contact 11 to contact, see 3B , The cathode layers 22 different capacitor elements are also by a single cathode contact 12 contacted.

In the 1 shown Anodenableiter represent wires. The Anodenableiter can in other, in 3A and 3B variants presented to be strip-shaped. The rod-shaped anode body 201 to 203 have in the 1 and 3A a rectangular or square cross-section. It is also possible to form the rod-shaped anode body cylindrical or with any other cross-section.

In 4A an advantageous variant of the capacitor is shown, in which a plurality of capacitor elements are arranged side by side in a row, wherein a plurality of rows R1, R2, R3 of capacitor elements are stacked one above the other. Each capacitor element comprises an anode body 201-j to 203-j , a dielectric layer not shown here and a cathode layer disposed thereon 22-j , The anode body 201-j . 202-j . 203-j or the cathode layers 22-j are assigned to the row Rj, where j = 1, 2, 3.

The electrical connections between the capacitor elements of a Row and between the rows of capacitor elements are solid Lines indicated.

In 4B is shown as multiple rows of capacitor elements through a single anode terminal 11 can be contacted. The anode connection 11 is folded inside the housing S-shaped.

The cathode connection 12 is fixed to the cathode layer 22-1 the capacity in the first row 201-1 . 202-1 . 203-1 connected (see also 3B and 4A ).

The first connector 41 is simply angled here. The connector 41 is at its first end to the cathode terminal 12 and at its second end with the cathode layer 22-2 the capacitor located in the second row R2 electrically and mechanically fixed. That with the first connector 41 partially overlapping second connector 42 is at its first end with the first connector 41 and at its second end with the cathode layer 22-3 connected in the third row R3 capacity electrically and mechanically fixed.

The various superimposed rows of capacitor elements can also be connected to each other in some other way. Alternatively to the in 4B In the variant shown, it is also possible to use partially overlapping connecting elements, which are preferably strip-shaped, also for the connection between the anode conductors arranged in different rows R1, R2, R3.

4C shows a variant of the capacitor with a plurality of rows of capacitor elements R1, R2, R3 in a housing, wherein the connection between the rows by means of double or Z-shaped angled connecting elements 41 to 44 he follows. The cathode connection 12 is solid with cathode layers 22-1 connected to the first capacity row R1. The first connection element 41 is solid at its first end with cathode layers 22-2 the second row R2 and at its second end fixed to the cathode terminal 12 connected. The second connection element 42 is solid at its first end with cathode layers 22-3 the third row R3 and at its second end fixed to the first connecting element 41 connected.

The anode connection 11 is fixed with Anodenableitern 21-1 connected to the first row R1. The third connection element 43 is solid at its first end with anode conductors 21-2 the second row R2 and at its second end fixed to the anode terminal 11 connected. The fourth connection element 44 is solid at its first end with anode conductors 21-3 the third row R3 and at its second end fixed to the third connecting element 43 connected. The connectors 41 to 44 in 4B . 4C are preferably metal strips.

On the bottom of the case 10 are to reduce the height of the capacitor suitable recesses for receiving SMD contacts 11a . 12a educated.

In the in 4A . 4B and 4C illustrated embodiment, all anode body in the same housing 10 arranged. In another, in 5A . 5B and 6 In the variant shown, it is possible to have several, respectively separate connections - anode connections 11-1 . 11-2 . 11-3 and cathode connections 12-1 . 12-2 . 12-3 - To arrange having capacitors C1, C2, C3 one above the other and firmly connected to each other.

Each capacitor Cj has outer tabs - the anode terminal 11-j and the cathode connection 12-j - on, where j = 1, 2, 3 5B the capacitor arrangement shown are the partially overlapping anode terminals with each other z. B. firmly connected by means of a spot weld. The anode connection 11-1 of the lowest capacitor C1 is folded on the underside (see 6 . 7 ) that it forms the anode-side surface mountable outer terminal of the overall assembly.

In 6 is shown that also the cathode connections 12-1 . 12-2 . 12-3 the one above the other ordered capacitors C1, C2, C3 z. B. are firmly connected by spot welding, soldering or bonding. The cathode connection 12-1 of the lowermost capacitor C1 forms a cathode-side surface mountable outer terminal of the overall assembly below.

In 6 Each capacitor C1 to C3 is a separate housing 10-1 . 10-2 and 10-3 assigned. The arranged in a row anode body of the same capacitor share a common housing. In 6 are the anode connections 11-1 . 11-2 and 11-3 different capacitors outside the capacitor housing 10-1 . 10-2 . 10-3 electrically and mechanically firmly connected. Also the cathode connections 12-1 . 12-2 and 12-3 different capacitors are firmly connected outside the capacitor housing. In contrast, in 4B the electrical connection of the arranged in different rows R1, R2, R3 capacitor elements within the common housing 10 , The connection of the cathode layers of the arranged in different rows of capacitances takes place in 4B within the common housing.

In 7 Another possibility for connecting stacked capacitors C1, C2 and C3 is presented. The anode connections 11-2 . 11-3 the upper capacitors are Z-shaped and the anode terminal 11-1 of the lowermost capacitor U-shaped angled.

capacitors were shown using only a few embodiments. However, they are not on these or specific applications limited. As material for the anode body can Any suitable alloys or valve metals are used. The capacitors can in particular chip capacitors, z. B. tantalum / niobium capacitors be.

C1, C2, C3

First, second or third capacitor

R1, R2, R3

first, second or third row of condensers

ELEMENTS

10

casing

10-1

Housing of first capacitor C1

10-2

Housing of second capacitor C2

10-3

Housing of third capacitor C3

11

anode of the capacitor

12

cathode of the capacitor

11a, 12a

External connections of the capacitor

11-j

Anode connections of the one above the other stacked

capacitors, j = 1, 2, 3

12-j

Cathode connections of the one above the other stacked

capacitors

201,202,203

 anode body

201-j, 202-j, 203-j in j.

 line arranged anode body

21

anode conductor

22

cathode layer

23

dielectric layer

41.42

in the casing arranged connecting straps

Claims (16)

Electric capacitor with several in one housing ( 10 ) arranged capacitor elements, each having a rod-shaped anode body ( 201 . 202 . 203 ) exhibit. Capacitor according to Claim 1, in which the anode bodies ( 201 . 202 . 203 ) are arranged side by side. Capacitor according to Claim 2, in which the anode bodies ( 201 . 202 . 203 ) are arranged in a row. Capacitor according to Claim 3, in which the anode bodies ( 201-1 . 202-1 . 203-1 . 201-2 . 202-2 . 203-2 . 201-3 . 202-3 . 203-3 ) are arranged in several superimposed rows. Capacitor according to one of Claims 1 to 4, in which the anode bodies ( 201 . 202 . 203 ) each have a rectangular cross-section. Capacitor according to one of Claims 1 to 4, in which the anode bodies ( 201 . 202 . 203 ) are each cylindrical. A capacitor according to any one of claims 1 to 6, wherein in each anode body from the interior of the anode body ( 201 . 202 ) an anode conductor ( 21 ) stands out. A capacitor according to claim 7, wherein each capacitor element has one on the inner and outer surfaces of the anode body ( 201 . 202 ) arranged dielectric layer ( 23 ) and one on the dielectric layer ( 23 ) arranged cathode layer ( 22 ). A capacitor according to claim 7 or 8, wherein the anode conductors ( 21 ) inside the case contacted by a common first terminal. A capacitor according to claim 9, wherein the common first terminal is an anode terminal ( 11 ), which is led out of the housing. Capacitor according to one of Claims 8 to 10, in which the cathode layers assigned to the various capacitor elements ( 22 ) are contacted in the housing interior by a common second terminal. A capacitor according to claim 11, wherein the common second terminal is a cathode terminal ( 12 ), which is out of the housing ( 10 ) is led out. A capacitor according to any one of claims 10 to 12, wherein the anode terminal ( 11 ) and the cathode connection ( 12 ) of the capacitor contacts a first row (R1) of capacitors, wherein at least one further row (R2, R3) of capacitances with the anode terminal ( 11 ) by a first connection element and with the cathode connection ( 12 ) is mechanically fixed and electrically connected by a second connecting element, and wherein, in the case of several further rows of capacitances, these rows (R2, R3) are mechanically fixed and electrically connected to one another on the anode or cathode side by a third connecting element. A capacitor according to any one of claims 1 to 13, wherein different ones Capacitor elements inside the housing are interconnected parallel to each other. Capacitor arrangement with a plurality of superimposed capacitors (C1, C2, C3) according to one of claims 1 to 14, wherein in the housing ( 10-1 . 10-2 . 10-3 ) of the respective capacitor (C1, C2, C3) a plurality of capacitor elements are arranged side by side, each having a rod-shaped anode body ( 201-1 . 202-1 . 203-1 ; 201-2 . 202-2 . 203-2 ; 201-3 . 202-3 . 203-3 ) exhibit. Capacitor arrangement according to Claim 15, in which two capacitors (C1, C2) are connected to one another by means of their anode connections ( 11-1 . 11-2 . 11-3 ) and cathode connections ( 12-1 . 12-2 . 12-3 ) are mechanically fixed and electrically connected.