WO2021250099A1

WO2021250099A1 - Surge protection element

Info

Publication number: WO2021250099A1
Application number: PCT/EP2021/065466
Authority: WO
Inventors: Thomas Feichtinger; Pavol Dudesek
Original assignee: Tdk Electronics Ag
Priority date: 2020-06-10
Filing date: 2021-06-09
Publication date: 2021-12-16
Also published as: DE112021003204A5

Abstract

The invention relates to a surge protection element which is based on a ceramic body (2) and serves to protect a plurality of high-frequency data lines, the surge protection element comprising a plurality of external contacts (3, 4, 5, 6) and two superposed discharge vias (7, 12).

Description

Overvoltage protection element

The invention relates to an overvoltage protection element.

Very fast high-frequency data lines or interfaces of such high-frequency data lines are part of many common electronic applications, such as USB, HDMI, Ethernet, Gigabit Ethernet or, in particular, automotive multi-gig.

Corresponding high-frequency data lines are usually operated at operating voltages of less than 100 V. For example, the operating voltages can be 24 V, 48 V, or 70 V.

The data transfer rates can be up to 10 gigabit / s.

Corresponding high-frequency data lines are sensitive to overvoltages. The overvoltages can have various causes, for example electrostatic charging or the like.

Accordingly, surge protection solutions or ESD protection solutions (ESD: Electrostatic Discharge) are required.

In modern electronic applications it is important that as many data lines as possible can be routed compactly, i.e. in the smallest possible space. Accordingly, ESD protection solutions are required which take up little space. In addition, the ESD protection solutions should not interfere with the signal line, neither during normal operation nor during an overvoltage event. This is particularly important for strip conductors and especially in the automotive multi-gig area.

On the one hand, corresponding ESD protection solutions should have the lowest possible parasitic capacitances, and on the other hand, couplings between the data lines must be prevented.

Examples of different ESD protection solutions can be found in US 2010/0157496 A1 or EP 3644340 A2.

An example of the ESD protection of several signal lines can be found in US Pat. No. 7099131 B2.

The patent specification discloses both a single surge arrester for protecting a single data line and an integrated surge arrester for protecting multiple data lines.

All surge arresters described in US 7099131 B2 are constructed in the feedthrough design. This means that one or more signal lines are routed from the outside to a ceramic component, there are connected to an electrode on the ceramic component and then passed through a conductor or an internal electrode in the ceramic component through the component and then through an output electrode to be led back onto a conductor track.

A corresponding data line according to US Pat. No. 7099131 B2 is protected by a gas-filled cavity in contact with a data line is available, which is routed as an internal electrode through the ceramic body of the surge arrester. The contact surface between the data line inner electrode and the cavity represents a discharge surface. There is another discharge surface on the side of the cavity opposite the data line inner electrode. This is part of an internal ground electrode, which is routed perpendicular to the data line or the data lines through the ceramic component. The cavity thus forms a type of discharge via.

Basically, here and in the following, “discharge via” is understood to mean a device which has a non-linear current-voltage behavior applied voltage (usually an overvoltage) is significantly reduced, which is why a current flow can take place through the discharge via. Preferably, "discharge via" can be understood to mean a device which has a non-linear current-voltage behavior and offers a discharge device in a laminated multi-layer body, in which the discharge current flows mainly perpendicular to the lamination direction. A proportion of more than 50% can be mainly vertical.

Thus, an integrated surge arrester for protecting several data lines according to US Pat. No. 7099131 B2 has a parallel arrangement of data line inner electrodes (feedthroughs) through the ceramic. Each of these signal lines is connected by a corresponding discharge via to the common ground line through the ceramic component. A corresponding design has the advantage that lines can be protected comparatively close to one another in a common component. The corresponding feedthrough design also has advantages for mounting on a corresponding circuit board or on corresponding strip conductors.

However, the corresponding design also has some disadvantages. The conductor tracks in the strip conductor have a defined distance. The coupling between the conductor tracks is defined by the distance and the dielectric constant of the medium between the conductor tracks.

The "free" conductor tracks, i.e. outside of the components, have a low coupling and a defined impedance, since the dielectric constant e of the surrounding medium, air, is small (approx. 1).

Since the mutual distance between the conductors in the ceramic component is roughly the same as the distance between the "free" conductor tracks, but the dielectric constant of the ceramic is usually greater than that of air, the coupling between the conductor tracks in the surge arrester is increased and, if necessary, the impedance in the area of the surge arrester changed.

In addition, it can be disadvantageous that the signal lines are all protected against the same ground line. Any flashovers (ESD event) can therefore more easily disrupt neighboring lines.

It is an object of the present invention to provide an overvoltage protection element which has a plurality of Protects high-frequency data lines while keeping the coupling of the data lines as low as possible.

In accordance with this requirement, an overvoltage protection element is provided which has a ceramic body, at least one first discharge via and a second discharge via, the first discharge via being formed between a first discharge zone on the top of the first discharge via and a second discharge zone on the underside of the first discharge via is, the second discharge via is formed between a third discharge zone on the top of the second discharge via and a fourth discharge zone on the underside of the second discharge via, the first discharge zone is connected to a first internal electrode with a first external contact, the second discharge zone is connected to a second internal electrode a second external contact, the third discharge zone is connected to a third external contact via a third internal electrode, the fourth discharge zone is connected to a fourth external contact via a fourth internal electrode.

The discharge zones can be designed, for example, as part of the respective internal electrode to which they are connected.

The ceramic body can comprise a ceramic material. In order to minimize coupling, the dielectric constant ε of the ceramic material should be as small as possible. It is considered advantageous if the ceramic material has a dielectric constant ε <20. It is considered more advantageous if the ceramic material has a dielectric constant of ε <10. For example, the ceramic material can be an HTCC or LTCC ceramic. The ceramic material can contain aluminum oxide. In addition, the ceramic material can contain glass.

The ceramic body is preferably a laminated multi-layer body. Here, the top and bottom can be understood as two opposite sides or two opposite directions parallel to the lamination direction. Thus, the terms top and bottom can be understood not only in relation to an absolute orientation in space, but alternatively also in relation to one another, the terms denoting two opposite sides of an overvoltage protection element or a ceramic body. The lamination direction can be understood as the vertical direction. The direction perpendicular to the lamination direction can be understood as the horizontal direction. The horizontal direction is thus preferably a direction parallel to the laminated layers.

Thus, the top and bottom can each designate two opposite sides of an object in the lamination direction. In this case, the surface normals of the upper and lower side are preferably oriented parallel to the lamination direction.

The internal electrodes are preferably designed to be flat. It is preferred here that the surface of the internal electrodes each run in horizontal planes. It is further preferred that the discharge zones also have a main extent in the planar direction of the internal electrodes. In this way, the internal electrodes can each define a horizontal surface. In one embodiment of the overvoltage protection element, the first discharge via can be arranged vertically above the second discharge via.

This means that, according to this preferred aspect, the first and the second unloading via are not formed exclusively next to one another, as is the case according to the prior art described above, but that the first unloading via is arranged above the two unloading via. That is, the first and the second unloading via can be offset in the horizontal direction, but the first unloading via is at all times above the second.

For example, all internal electrodes can also be formed on different horizontal planes.

According to one embodiment of the overvoltage protection element, the first external contact can be a first signal line contact, the second external contact can be a first ground contact and the first internal electrode can connect the discharge zone exclusively to the first signal line contact.

This means that in this embodiment the signal which can be applied to the first signal line contact is not passed through the overvoltage protection element. For example, the signal can be routed past the overvoltage protection element in a signal line.

Signal line contacts can preferably be routed in the opposite direction from the respective ESD protective device, that is to say from the discharge vias, outwards to different sides of the overvoltage protection element. Such an arrangement can be advantageous since the second discharge zone or the second internal electrode can be connected to ground. It can act as a shield between the discharge zone connected to the first signal line contact and the further discharge zones located on the second discharge via. Coupling between the internal electrodes in the overvoltage protection element can thus be reduced.

In addition, such an arrangement can also advantageously be designed in such a way that the inner electrode connected to the first signal line contact has the greatest possible distance in the vertical direction from the second discharge via in the area of the discharge vias.

According to a further aspect of the invention, the overvoltage protection element can be designed such that the third external contact is a second ground contact, the fourth external contact is a second signal line contact and the fourth internal electrode connects the fourth discharge zone exclusively to the second signal line contact.

In combination with the previous embodiment, this can result in further advantages. According to such a structure, the distance between the internal electrodes or the discharge zones, which are in contact with signal lines, can be kept as large as possible. This can reduce the coupling of the signal-carrying internal electrodes.

In addition, both internal electrodes or both discharge zones, which are grounded, can be vertical be arranged between the internal electrodes, which are connected to signal line contacts. In this way, the discharge zones or internal electrodes connected to the signal line contacts can be shielded from one another and coupling between the signal lines can be prevented.

Furthermore, appropriately constructed overvoltage protection elements can be used particularly advantageously in arrangements in which the signal lines are routed past the component.

For example, a first signal line can be in contact with the first signal line contact and a second signal line can be in contact with the second signal line contact. In addition, both signal lines can be routed past the overvoltage protection element.

Because the signal lines can be routed past the overvoltage protection element, the influence of the overvoltage protection element on the signals can be minimized. For example, coupling can be minimized.

According to a further aspect of the invention, the second internal electrode can connect the second discharge zone exclusively to the first ground contact and the third internal electrode can connect the third discharge zone only to the second ground contact.

Such an arrangement can have the advantage that the grounded internal electrodes or grounded discharge zones are galvanically more easily decoupled can by connecting the ground contacts on the ceramic component with various galvanically decoupled ground lines.

This can bring about an advantage in comparison to a structure according to the prior art described above, since in the prior art all signal lines are protected from a common ground line.

According to another aspect of the invention, the second internal electrode can connect the second discharge zone to both the first and the second ground contact and the third internal electrode can connect the third discharge zone to both the first and the second ground contact.

This arrangement, in which the ground contacts are fed through the overvoltage protection element in a feedthrough design, can be more space-saving when installed in a circuit than the aforementioned arrangement, since only one ground line has to be brought to the overvoltage protection element in a circuit.

In addition, a less expensive process can be used for such a structure. For example, in a manufacturing process based on stacking green sheets or lamination of green sheets, identical green sheets which are provided with an internal electrode can be used to form the second and third internal electrodes.

According to a further aspect of the invention, the overvoltage protection element can be designed such that - an upper side of the ceramic body is that outer surface of the ceramic body which is arranged above the first discharge zone and is closer to this first discharge zone than to all other discharge zones,

- an underside of the ceramic body is an outer surface of the ceramic body opposite the upper side,

- a first, a second, a third and a fourth side surface are the further outer surfaces of the ceramic body,

- the first signal line contact is formed on the first side surface,

- The second signal line contact is formed on the third side surface, which is opposite the first side surface,

- The first ground contact is formed on the second side surface, and

the second ground contact is formed on the fourth side face, which is opposite the second side face.

The overvoltage protection element is preferably cuboid.

A corresponding cuboid structure can facilitate the installation of the overvoltage protection element directly on conductor tracks.

In addition, by arranging the signal line contacts on opposite surfaces, the distance between them can be kept as large as possible, which means that coupling of the signals can be further reduced. According to a further aspect of the invention, the overvoltage protection element can be designed such that

- all internal electrodes are strip-shaped and each run in a plane parallel to the top of the ceramic body,

- the first inner electrode is aligned orthogonally to the first side surface,

- the second inner electrode is aligned orthogonally to the second side surface,

- the third internal electrode is aligned orthogonally to the third side surface, and

- The fourth internal electrode is aligned orthogonally to the fourth side surface.

That is, according to this embodiment, the first inner electrode can be aligned perpendicular to the second inner electrode. The third inner electrode can also be aligned perpendicular to the fourth inner electrode.

As a result, the overlap between the inner electrodes, which are connected to ground, and the inner electrodes, which are connected to signal lines, can be limited to the area of the respective discharge vias. This can reduce parasitic capacitances.

With a corresponding arrangement of the internal electrodes, the internal electrodes, which are connected to the signal line contacts, can also be led away from one another in opposite directions. This allows coupling of the signals to be further reduced.

According to a further aspect of the invention, the overvoltage protection element can be designed so that the the first unloading via and the second unloading via do not have a horizontal offset.

This means that in this embodiment, viewed from above, that is to say in a direction from top to bottom in the lamination direction, the first unloading via is arranged directly above the second unloading via.

Such an embodiment can at the same time enable the external contacts to be arranged on the ceramic body in as small a space as possible while maintaining good shielding of the signals, reduced parasitic capacitance and reduced coupling of the signals. For example, the width of the opposite ground contacts can be adapted to the width of the discharge vias.

According to another embodiment of the overvoltage protection element, the first discharge via can be arranged horizontally next to the second discharge via.

That is, according to this aspect, the first unloading via can only be offset horizontally to the second unloading via, or it can be offset both horizontally and vertically to the second unloading via.

An exclusively horizontal offset can have the advantage that the overvoltage protection element can be made flatter.

According to a further aspect, the overvoltage protection element can have a cavity which is formed between the first discharge zone and the fourth discharge zone.

The second discharge zone can pass through the cavity free-standing areas of the second internal electrode are formed. The third discharge zone can be formed by a region of the third internal electrode that is free in the cavity. The cavity can be filled with a filling gas.

In a corresponding structure, a common cavity can comprise two gas-filled discharge spaces, which each form the first and second discharge via.

In the event of a harmful overvoltage, for example on the signal line which is connected to the first signal line contact, the ignition voltage of the filling gas, which is located between the first discharge zone and the grounded second discharge zone, can be exceeded. An electrical discharge is triggered through the filling gas and the overvoltage is diverted to ground.

The functional principle can generally correspond to the principle of the gas discharge vias described below

As a result of the continuous cavity, in addition to the first and second discharge vias, a further gas-filled area can be formed between the discharge vias. This area can be delimited at the top by the second internal electrode and at the bottom by the third internal electrode. Since the second and third discharge zones can be grounded, there is no electrostatic discharge between them. However, the filling gas can have a significantly lower dielectric constant than the ceramic material of the ceramic body.

For example, it is difficult to achieve dielectric constants of ε <5 for ceramic materials. On the other hand, the Dielectric constant of gases at room pressure can be described as a good approximation by ε = 1.

By arranging a further gas volume between the first and the fourth discharge zone in the embodiment described above, coupling of the signals can be reduced.

As explained below, the discharge vias designed as gas-filled cavities can also develop a similar effect.

In principle, one or more of the internal electrodes protruding into the cavity and free-standing in the cavity can subdivide the latter into isolated sections over the full cross-sectional area. This means that the corresponding internal electrodes can be led from the ground contacts to the cavity and then penetrate the cavity over its full cross-sectional area, so that the cavity is divided into closed sections. Depending on the embodiment, these internal electrodes can then be passed through to the opposite ground contact, or preferably end just behind the cavity in the ceramic body.

The corresponding internal electrodes can, however, also be guided through the cavity in such a way that they do not subdivide it into isolated sections, in that the internal electrodes are structured accordingly in the area of the discharge zones. For example, they can be perforated.

However, the corresponding internal electrodes can also protrude just a little way into the cavity. For example can the corresponding internal electrodes are led from the ground contacts into the cavity and end in this.

The corresponding internal electrodes can also cut the cross-sectional area of the cavity like a secant. That is to say, the discharge zones formed in this way correspond to only part of the cross-sectional area of the cavity.

Furthermore, discharge zones which are grounded or connected to a signal line can be planar. However, the corresponding discharge zones can also have a structuring in the direction of the discharge vias.

For example, they can be roughened. For example, they can also have spikes, that is to say they can have one or more pointed elevations, which preferably point in the direction of the opposite discharge zone.

According to a further aspect, the overvoltage protection element can be designed such that

- at least one fifth inner electrode is connected to at least one ground contact,

- the fifth inner electrode is aligned orthogonally to the second side surface of the ceramic body,

- The fifth inner electrode is arranged between the second and third inner electrode and

- The fifth inner electrode has a free-standing area in the cavity.

In other words, a further grounded internal electrode can thus be arranged between the two grounded internal electrodes or between the two grounded discharge zones. In the event that the discharge zones, which are grounded, are not completely planar but rather strongly roughened or have spikes and the discharge zone or the fifth inner electrode does not close off the volume of the respective discharge vias, the surface to which discharges can be directed can be achieved through the further electrode can take place, can be greatly increased.

In the event that the electrodes, which are connected to ground, are flat and have approximately the width of the cavity, the additional ground contact can effect even better shielding between the above and below discharge zones connected to the signal lines.

According to a further aspect, the overvoltage protection element can be designed in such a way that the first signal line contact encloses the first side surface in the form of a cap and the second signal line contact encloses the third side surface in the form of a cap.

For example, in the case of the cap-shaped enclosure, not only the respective above-mentioned side surface can be covered by the electrode, but the electrode also overlaps the adjacent side surfaces to a certain extent and also the top and / or bottom of the ceramic body. As a result, the component can be placed on lines to be protected and, for example, soldered on. This can represent a space-saving surge protection solution.

Thus, by enclosing the respective opposing side surfaces in the form of a cap, a particularly advantageous Installation of the overvoltage protection element in high-frequency conductor tracks are made possible.

- an upper side of the ceramic body is that outer surface of the ceramic body which is arranged above the first discharge zone and is closer to this first discharge zone than to all other discharge zones,

- the first signal line contact is formed on the first side surface,

- the first ground contact and the second ground contact are formed on the second side surface,

- A third ground contact is formed on the fourth side surface directly opposite the first ground contact,

- A fourth ground contact is formed on the fourth side surface directly opposite the second ground contact,

- the second inner electrode connects the second discharge zone to both the first and the third ground contact, - The third inner electrode connects the third discharge zone to both the second and the fourth ground contact.

The ceramic body is preferably designed in the shape of a cuboid.

According to the embodiment described above, the corresponding overvoltage protection element can have four ground contacts, of which two ground contacts each lie opposite one another and can be connected by internal electrodes. This means that both pairs of ground contacts can be connected to an electrically isolated ground. Thus, in each case a signal line contact, which is located on an end face of the ceramic body, can be protected by a galvanically independent ground contact via the respective discharge via. Thus, one of these ground contact pairs can preferably correspond to a single ground contact from the examples mentioned above, which is galvanically isolated from the other ground contact. The ground contact pairs formed here can be treated equivalent to a single ground contact from the previous examples with only two ground external contacts.

A corresponding structure may have the disadvantage that the two ground lines arranged next to one another in the ceramic body require more space, but an even greater distance between the first and the second signal line contact can be ensured in this way.

That is, the first and the second unloading via can not only be arranged vertically offset from one another, but can also be arranged horizontally offset from one another being. This ensures an even better decoupling.

- the second external contact is a first ground contact which is arranged on the first side surface of the ceramic body,

- the third external contact is a second ground contact, which is arranged on the third side surface of the ceramic body, which is opposite the first side surface,

- the first external contact is a first signal line contact which is arranged on the second side surface of the ceramic body,

- the fourth external contact is a second signal line contact which is arranged on the second side surface of the ceramic body,

- A third signal line contact is formed on the fourth side surface directly opposite the first signal line contact, - A fourth signal line contact is formed on the fourth side surface directly opposite the second signal line contact,

- the first inner electrode connects the first discharge zone to both the first and the third signal line contact,

- The fourth inner electrode connects the fourth discharge zone to both the second and the fourth signal line contact.

The ceramic body is preferably designed in the shape of a cuboid.

A corresponding arrangement can represent an example of an overvoltage protection element in a feedthrough design. It can thus represent a feedthrough variant of the present invention.

For example, the appropriately constructed overvoltage protection element can be used to protect a first and a second signal line. The first signal line can be routed through the overvoltage protection element in that a first signal line to be protected is routed to the first signal line contact, the signal is routed via the first internal electrode through the ceramic body to the third signal line contact, and then from the third

Signal line contact is routed back to a first signal derivative. Correspondingly, a second signal line can be passed through the overvoltage protection element via the second and fourth signal line contact and the fourth internal electrode. The above-described arrangement or the above-described application principle can be used advantageously in particular for the ESD protection of strip conductors with a defined impedance.

As already described above, an overvoltage protection element in the feedthrough design can be installed in a particularly space-saving manner.

However, in contrast to the prior art described in the introduction, a better decoupling of the signals to be protected can be achieved.

For example, a horizontal offset of the discharge vias can be achieved in addition to the vertical one.

It is thus possible in this embodiment, with the same horizontal spacing of the external contacts, similar to a design according to the prior art described above, to achieve a greater spacing between signal-carrying internal electrodes. Correspondingly, more efficient decoupling can be achieved.

According to a further aspect of the last-mentioned embodiment, the second internal electrode can connect the second discharge zone exclusively to the first ground contact. The third internal electrode can connect the third discharge zone exclusively to the second ground contact. In addition, a decoupling cavity filled with filling gas can be formed between the first discharge via and the second discharge via. Since the grounded discharge zone of the respective discharge vias is only connected to one ground contact, the two grounded discharge zones can be connected to galvanically separated grounds. This further improves the decoupling.

In addition, a decoupling cavity can be formed in the interior of the ceramic body. The decoupling cavity is preferably located between the first and the second discharge via. That is to say, it can be arranged, for example, in the middle between the first and the second unloading via.

The shape of the decoupling cavity can be chosen as desired. The decoupling cavity can be cuboid, for example. In this case, a first side face of the cuboid cavity is preferably oriented parallel to the first side face of the cuboid ceramic body.

The decoupling cavity can, for example, also have a cylindrical shape. In this case, a circular top surface of the cylindrical cavity is preferably oriented parallel to the first side surface of the ceramic body.

The dimensions of the decoupling cavity can be chosen as desired.

It can be advantageous to design the height of the decoupling cavity, that is to say the extent in a direction parallel to the normal to the surface of the ceramic body, such that it corresponds at least to that of the vertical distance between the first and fourth internal electrodes. Will If the decoupling cavity is formed accordingly, the decoupling of the signal-carrying internal electrodes is improved.

It can be advantageous to make the depth of the decoupling cavity, that is to say the extension in a direction parallel to the normal to the second side surface, as large as possible.

It can be advantageous to make the length of the decoupling cavity, that is to say the extension in a direction parallel to the normal to the first side surface, as large as possible. The greater that section of the distance between the first and fourth internal electrodes that runs through the filling gas of the decoupling cavity, the lower the coupling between the first and fourth internal electrodes can be.

The coupling between signal-carrying internal electrodes in the space-saving feed-through design can be further improved by a corresponding decoupling cavity.

a third discharge via is formed between a fifth discharge zone on the upper side of the third discharge via and a sixth discharge zone on the lower side of the third discharge via,

a fourth discharge via is formed between a seventh discharge zone on the upper side of the fourth discharge via and an eighth discharge zone on the lower side of the fourth discharge via, - the fifth discharge zone is connected exclusively to the second ground contact via a sixth internal electrode,

- the sixth discharge zone is connected via a seventh internal electrode to both a fifth signal line contact and a seventh signal line contact,

- the seventh discharge zone is connected to both a sixth signal line contact and an eighth signal line contact via an eighth internal electrode,

- the eighth discharge zone is connected exclusively to the first earth contact via a ninth internal electrode,

- The fifth signal line contact directly next to the first signal line contact and together with the sixth signal line contact between the first signal line contact and the second

Signal line contact are arranged on the second side surface of the ceramic body, and

the seventh signal line contact is arranged on the fourth side surface of the ceramic body opposite the fifth signal line contact, and

- The eighth signal line contact is arranged on the fourth side surface of the ceramic body opposite the sixth signal line contact.

It is thus possible to protect more than two signal lines against overvoltages using the same principle as with two signal lines.

According to a further aspect, the overvoltage protection element can be designed in such a way that the two discharge zones of two directly adjacent discharge vias, which are electrically conductive with one of the others Signal line contacts are connected electrically independent signal line contact, are arranged on opposite sides of the respective discharge vias.

That is, if two opposite signal line contacts, which are arranged on the ceramic body in feedthrough design, are connected to one another via an inner electrode, and two further opposite signal line contacts, which are connected to one another via a further inner electrode, feedthrough design, are arranged directly adjacent the discharge zones, which are electrically connected to the internal electrodes described, are arranged on opposite sides of the respective discharge vias via which the signal line contacts described are protected against overvoltages.

In addition, this can mean that the discharge zones of directly adjacent discharge vias connected to ground contacts are arranged on mutually facing sides of the discharge vias.

The discharge zone of a discharge vias connected to signal line contacts is preferably arranged on the side of the discharge vias which faces away from all of the discharge zones of all adjacent discharge vias connected to signal line contacts.

Such arrangements are advantageous since the distance between the signal-carrying internal electrodes can be maximized, which means that coupling can be reduced.

According to a further aspect of the invention, the overvoltage protection element can be designed so that the The first discharge via is designed as a cavity filled with filling gas between the first and the second discharge zone. In addition, the second discharge via can be designed as a cavity filled with filling gas between the third and fourth discharge zones.

The shape of the cavities or cavities filled with filling gas

Discharge vias, so-called gas discharge vias, can be selected as desired.

For example, a gas discharge via can be cylindrical. The top and bottom of a corresponding cylindrical gas discharge via can include the discharge zones arranged on the gas discharge via. For example, the top or the bottom of a cylindrical gas discharge via can be formed over the entire surface by the discharge zones arranged on the gas discharge via. The jacket of a cylindrical gas discharge vias can preferably be defined by the surrounding ceramic material.

The use of gas discharge vias can have several advantages.

For example, gas discharge vias are ideal for protecting high-frequency data lines against overvoltages.

As stated above, high frequency data lines can typically have operating voltages below 100 volts. The ignition voltage of the gas discharge vias should then be greater than the operating voltage of the respective high-frequency data line. For example, an ignition voltage of 100 V can be set in an overvoltage protection element with an operating voltage of 24 V. The ignition voltage of the gas discharge vias can be adjusted using several factors. According to Paschen's law, the breakdown voltage, i.e. the ignition voltage of a certain gas, is a function of the gas pressure and the distance between the discharge zones.

The ignition voltage can be adjusted accordingly by choosing the filling gas. For example, the fill gas can be a gas selected from the group consisting of nitrogen, hydrogen, argon or another noble gas. A mixture of the gases described above can also be used.

The gas can be introduced, for example, during the production process of the surge protection element. For example, the gas can be introduced into the corresponding cavities during the sintering of the ceramic body in that the sintering is carried out at a certain pressure in a corresponding gas atmosphere.

The ignition voltage can also be set by pressing the filling gas. The pressure of the filling gas can be adjusted, for example, by the pressure of the surrounding gas atmosphere during the sintering of the ceramic body.

It can be advantageous if the pressure of the filling gas corresponds approximately to atmospheric pressure, since this means that the ceramic does not have to compensate for a pressure difference between the gas discharge vias and the atmosphere during operation.

In principle, it can be advantageous if the ceramic material, which surrounds cavities filled with filling gas, have a has high relative density and low porosity in order to avoid an exchange of the filling gas with the atmosphere. For example, the ceramic material can have a relative density of 98% or greater after sintering. The ceramic material can preferably have a relative density of 99% or greater after sintering.

With regard to the embodiment in which a decoupling cavity is contained in the overvoltage protection element, its filling with filling gas can be carried out in the same way as that of the gas discharge vias.

The gas discharge vias and a decoupling cavity can thus be filled with filler gas in a common process step, for example by sintering in a filler gas atmosphere. This can enable simple process management.

In particular for a case in which the first discharge vias and the second discharge vias do not have a horizontal offset, gas discharge vias have the advantage that, in addition to the ESD protective function, they also have a decoupling effect. Since gases can have significantly lower dielectric constants than ceramic materials, and since the gas discharge vias can be arranged between the first and fourth internal electrodes, coupling between these internal electrodes can be reduced. The gas discharge vias can develop an effect similar to that of a decoupling cavity.

According to a further aspect, the overvoltage protection element can be designed in such a way that the ceramic material of the ceramic body, which is connected to the first discharge via and / or the second discharge via adjoins, is doped with an ignition aid.

The introduction of an ignition aid can make it easier to set the ignition voltage of a gas discharge vias. For example, a lowering of the ignition voltage can be achieved compared to a version without ignition aid.

The ignition aid can be introduced as doping into the ceramic material which surrounds a gas discharge via.

In contrast to previously used ignition aids such as graphite, which cover the outer walls of a gas-filled discharge vias, the process control can be simplified by doping the ceramic material.

For example, the ignition aid can be contained as a dopant directly in the ceramic material of one or more green sheets which contain a recess for forming a gas discharge vias. The corresponding green foils can easily be stacked together with further green foils to form a green foil stack.

Intermediate coating steps for the gas discharge via side surfaces can thus be avoided.

The ignition aid can comprise at least one element selected from the following group consisting of B, Sr, W or K.

The invention is explained in more detail below on the basis of exemplary embodiments and the associated figures. The figures are only used to illustrate the invention and are therefore only shown schematically and not true to scale. Individual parts can be enlarged or shown distorted with regard to the dimensions. Therefore, neither absolute nor relative dimensions can be derived from the figures. Identical or identically acting parts are provided with the same reference symbols.

FIG. 1 shows, in schematic views, a first exemplary embodiment of the present invention in a top view (FIG. 1A), in a view of a fourth side surface (FIG. 1B) and in a view of a first side surface (FIG. 1C).

FIG. 2 shows schematic cross sections of the first exemplary embodiment of the present invention.

FIG. 3 shows a second exemplary embodiment of the present invention in a schematic cross section.

FIG. 4 shows a third exemplary embodiment of the present invention in a schematic cross section.

FIG. 5 shows schematic views of a fourth exemplary embodiment of the present invention in a top view (FIG. 5A), a side view of the fourth side surface (FIG. 5B), and in a side view of the first side surface (FIG. 5C).

FIG. 6 shows a fifth exemplary embodiment of the present invention in a schematic cross section.

FIG. 7 shows a sixth exemplary embodiment of the present invention in a schematic cross section. FIG. 8 shows, in schematic views, a seventh exemplary embodiment of the present invention in plan view (FIG. 8A) and in side view of the fourth side surface (FIG. 8B).

FIG. 9 shows schematic cross sections of the seventh exemplary embodiment of the present invention.

FIG. 10 shows in schematic views an eighth exemplary embodiment of the present invention in plan view (FIG. 10A), in side view of the fourth side surface (FIG. 10B) and in side view of the first side surface (FIG. 10C).

FIG. 11 shows schematic cross sections of the eighth exemplary embodiment of the present invention.

FIG. 12 shows schematic views of a ninth exemplary embodiment of the present invention in plan view (FIG. 12A), in side view of the fourth side surface (FIG. 12B) and in side view of the first side surface (FIG. 12C).

FIG. 13 shows schematic cross sections of the ninth exemplary embodiment of the present invention.

FIG. 14 shows schematic cross sections of a tenth exemplary embodiment of the present invention.

FIG. 15 shows a schematic cross section of an eleventh exemplary embodiment of the present invention. FIG. 16 shows a twelfth exemplary embodiment of the present invention in a schematic top view (FIG. 16A), in a schematic side view of the fourth side surface (FIG. 16B) and in a schematic cross section (FIG. 16C).

FIG. 1 shows a first exemplary embodiment of the present invention in schematic views. An overvoltage protection element 1 is shown, which has a cuboid ceramic body 2. Figure 1A shows a plan view of the top of the

Overvoltage protection element 1 or on top of the cuboid ceramic body 2.

Figure 1B is a schematic view of the fourth side surface of the ceramic body.

FIG. 1C shows a schematic view of the first side face of the ceramic body.

In the present first exemplary embodiment, a first signal line contact 3 is formed as a first external contact on the first side surface of the ceramic body 2.

As can be seen in FIG. 1B, the first signal line contact 3 is designed in such a way that it extends in a clamp-like manner from the first side surface to part of the upper side or the lower side of the ceramic body 2.

In the first exemplary embodiment, the first signal line contact 3 is arranged centrally on the first side surface of the ceramic body 2. On the third side face, which is opposite the first side face of the ceramic body 2, a second signal line contact 5 is formed as a third external contact. Corresponding to the first signal line contact 3, the second signal line contact 5 also has a clamp-shaped overlap on the top or the bottom of the ceramic body 2.

The degree of overlap on the top or on the bottom of the ceramic body 2 of the first signal line contact 3 and the second

Signal line contact 5 can be different. Preferably, however, the degree of overlap can be the same as shown in FIGS. 1 a and b. A first ground contact 4 is designed as a second external contact on the second side surface of the ceramic body 2. This first ground contact 4 also has a clamp-like extension from the second side surface to the top or bottom of the ceramic body 2.

A second ground contact 6 is formed as a fourth external contact on the fourth side surface of the ceramic body 2. This also has a clamp-like extension from the fourth side surface to the top or bottom of the ceramic body 2.

The degree of expansion of the first ground contact 4 and the second ground contact 6 on the top or bottom of the ceramic body 2 can be different. Preferably, however, the clamp-like extension can also be the same. The clamp-like expansion of the ground contacts 4 and 6 and the signal line contacts 3 and 5 can be the same or different.

The dimensions of the first exemplary embodiment of the overvoltage protection element 1 can be selected as desired.

The dimensions of the overvoltage protection element 1 according to the first exemplary embodiment can be specified by the height h, length 1 and depth t of the overvoltage protection element 1. The height is the extension of the overvoltage protection element 1 parallel to the normal to the upper side of the ceramic body 2. The length corresponds to the extension parallel to the normal to the first side surface of the ceramic body 2. The depth corresponds to the extension parallel to the normal to the fourth side surface of the ceramic body 2.

For example, length times depth times height (1 × d × h) can be 1.6 mm × 0.8 mm × 0.6 mm. The dimensions can also be 2 mm × 1.25 mm × 0.8 mm or have other dimensions.

A ceramic material of the ceramic body 2 can be any desired ceramic material with a dielectric constant ε <20.

The ceramic material can be an LTCC ceramic, for example. For example, the LTCC ceramic can include alumina and glass.

All external contacts 3, 4, 5, 6 can each consist of any conductive material. Is preferred instead, a material that enables the overvoltage protection element 1 to be introduced into electronic applications, for example via soldering.

The electrodes can consist of a conductive metal or a metal alloy, for example. The external contacts can comprise, for example, one or more metals selected from a group consisting of gold, silver, copper, nickel, tungsten, tantalum or molybdenum.

FIG. 2 shows schematic cross sections of the first exemplary embodiment of the overvoltage protection element 1 as shown in FIGS. 1A to 1C.

FIG. 2A shows a schematic cross section of the first exemplary embodiment along the line A - B marked in FIG. 1A.

FIG. 2B shows a schematic cross section along the line EF of the first exemplary embodiment of the overvoltage protection element 1 drawn in FIG. 1B. The cross section runs parallel to the top of the overvoltage protection element 1. The cross section runs through a first internal electrode 9, as described below.

FIG. 2C shows a schematic cross section of the first exemplary embodiment of the overvoltage protection element 1 along the line C - D shown in FIG. 1A. The cross section runs parallel to the first side surface of the Overvoltage protection element 1 and has a central course through this.

As can be seen in FIG. 2A, a first unloading via 7 and a second unloading via 12 are arranged in the first exemplary embodiment.

Both discharge vias 7 and 12 are gas discharge vias. That is, they are designed as cylindrical cavities in the ceramic body 2 and filled with a filling gas.

The respective cylinder tops and bottoms are designed parallel to one another and are designed parallel to the top and bottom of the ceramic body 2, respectively.

The first discharge via 7 is arranged in the ceramic body 2 directly above the second discharge via 12. This means that the two discharge vias 7 and 12 have no horizontal and only a vertical offset to one another.

The dimensions of the first discharge vias 7 and the second discharge vias 12 can be selected as desired.

For example, the first unloading via 7 and the second unloading via 12 can have the same dimensions, that is, they can be embodied in the same way. Assuming that both discharge vias are filled with the same filling gas under the same pressure, two signal lines can be protected against the same overvoltage conditions. This design is particularly practical if two signal lines have the same operating voltages and the same overvoltage protection requirements. The first discharge via 7 and the second discharge via 12 can also have different dimensions and / or different filling gas conditions (type of filling gas,

Pressure). In this way, two signal lines with different operating voltages and / or different overvoltage protection requirements can be protected in one component.

A first discharge zone 8 is arranged on the upper side of the first discharge vias 7. The first discharge zone 8 can, for example, completely form or cover the upper side of the first discharge vias 7, as is shown in FIGS. 2A and 2B.

In principle, the first discharge zone 8 can also be formed only on a part of the upper side of the cylindrical gas discharge vias 7.

The first discharge zone 8 is connected exclusively to the first signal line contact 3 via the first internal electrode 9.

The first discharge zone 8 can be designed as part of the first internal electrode 9. The first internal electrode 9 runs in the form of a strip from the first signal line contact 3 on the first side surface of the ceramic body 2 to at least the first discharge zone 8, which is arranged in the first discharge via 7.

The first internal electrode 9 has a strip shape. This means that the expansion of the first internal electrode 9 in the direction of the height of the ceramic body 2 is significantly less is as the extension in the direction of the length and the depth of the ceramic body 2.

The first internal electrode 9 runs at the level of the first discharge zone 8, perpendicular to the first side surface of the ceramic body 2 and parallel to the surface of the ceramic body 2.

In principle, the shape of the first internal electrode 9 can be selected as desired in accordance with the parameters specified above. For example, it can have a rectangular shape in plan view, as shown in Figure 2B. In principle, it is also possible for the termination of the first internal electrode 9 to be semicircular in the area of the first discharge vias 7. This means that the termination of the first internal electrode 9 is defined by the cylinder jacket of the first discharge vias 7.

The width of the first internal electrode 9, that is to say the extension in the direction of the depth of the ceramic body 2, can in principle be selected as desired. It can be smaller than the diameter of the cylindrical first discharge vias 7, just as large as the diameter of the cylindrical first discharge vias 7 or, as shown in FIG first signal line contact 3.

As described above, the first discharge zone 8 is formed on the upper side of the first discharge vias 7. The first discharge zone 8 can, for example, have a flat design in the direction of the first discharge vias 7. The first unloading zone 8 can also be structured in this direction. That is, it can be roughened or have spikes.

A second discharge zone 10 is arranged below the first discharge zone 8 on the underside of the first discharge vias 7. The second discharge zone 10 is designed similarly to the first discharge zone.

This means that the second discharge zone 10 can be formed on the entire underside of the first discharge vias 7. As shown in FIG. 2A and FIG. 2C, respectively. The second discharge zone can, however, also be formed only on a partial area of the underside of the first discharge vias 7.

In the present exemplary embodiment, the second discharge zone 10 is connected to both the first ground contact 4 and the second ground contact 6 via the second internal electrode 11.

The second internal electrode 11 has a strip-like structure, corresponding to the definition of the first internal electrode 9, the width of the second internal electrode 11 being the extension in the direction of the length of the ceramic body 2 and the length of the second internal electrode 11 being the extension in the direction of the depth of the ceramic body 2 is.

The second discharge zone 10 can be designed as part of the second internal electrode 11.

The second inner electrode 11 runs at the level of the second discharge zone 10, perpendicular to the second side surface of the ceramic body, from the first ground contact 4 to the second ground contact 6. It is preferred to arrange the second inner electrode 11 centrally between the first and third side surfaces of the ceramic body.

In principle, the width of the second internal electrode 11 can be selected as desired.

It is preferred that the width of the second internal electrode 11 is selected at least so that it is greater than or equal to twice the distance between the center of the circle on the top of the cylindrical first discharge vias 8 and the end of the first internal electrode 9 lying in the ceramic.

That is, in a projection of the first internal electrode 9 and the second internal electrode 11 onto the underside of the ceramic body 2, the projection area of the end of the first internal electrode 9, which is not connected to the first signal line contact 3, lies completely within the projection area of the second internal electrode 11.

With such a structure, the second internal electrode 11 connected to ground contacts can serve as an efficient shield for the first internal electrode 9 connected to the first signal line contact 3 in the direction of the second discharge via 12.

The basic structure of the second discharge vias 12 corresponds to that of the first discharge vias 7.

The third discharge zone 13 is arranged on the upper side of the second discharge vias 12. The third inner electrode 14 runs at the level of the third discharge zone 13. Otherwise, the third inner electrode 14 can be designed in exactly the same way as the second inner electrode 11.

The fourth internal electrode 16 connects the fourth discharge zone 15 on the underside of the second discharge vias 12 exclusively to the second signal line contact 5.

The fourth discharge zone 15 can be designed to be equivalent to the first discharge zone 8.

The fourth inner electrode runs at the level of the fourth discharge zone 15 and runs perpendicular to the third side surface of the ceramic body 2. Equivalent to the properties set out above for the first inner electrode 9, the fourth inner electrode 16 can extend at least to the fourth discharge zone 15. However, viewed from the third side surface, it can also end behind the fourth discharge zone 15 in the ceramic body 2.

In principle, the inner electrodes 9, 11, 14 and 16 and the discharge zones 8, 10, 13 and 15 can be formed from a suitable conductive material. They can be formed from a metal, for example, or a metallic alloy. For example, a corresponding metal or a metallic alloy can contain elements from the group comprising copper, nickel, tungsten, tantalum, molybdenum or the like. The overvoltage protection element 1 according to the first embodiment of the present invention can be manufactured by any process.

For example, it can be made by a multilayer ceramic process. Correspondingly, the ceramic body 2 can be a multilayer ceramic.

A corresponding process can include, for example, the following steps:

In a first step, a large number of ceramic green sheets are provided which contain a ceramic base material. The ceramic base material can be converted into the ceramic material of the ceramic body 2 by sintering. Some of the green foils are completely continuous. Other green foils contain a hole from which one of the discharge vias is formed during the manufacturing process. Corresponding holes can be made in green sheets, for example, by laser ablation.

To form a green sheet stack, the holes in the green sheets with holes can be filled with an organic material. This organic material can improve the stability of the green sheets during the process.

One or more continuous green sheets are stacked as the bottom layer. A fourth internal electrode 16 is applied to the top green sheet of this stack. It runs from the edge of the stack, which after completion forms the third side surface of the ceramic base body, into the center of the stack and ends there. The fourth Inner electrode 16 can be applied, for example, by screen printing a metal-containing paste. One or more green sheets which contain a hole in the center are stacked on the existing stack with the fourth internal electrode 16. The height of the respective green sheets with holes and the number of these in the stack is selected according to the height of the second discharge vias 12 to be achieved.

Another continuous green sheet is stacked on the stack formed in this way. This has the third internal electrode 14 on its underside.

In the case of using an organic filling of the holes in the green foils with holes, the third internal electrode 14 can also be applied to the top of these green foils.

The third internal electrode 14 can be applied again, for example, by screen printing. It runs from the end of the green pile, which will form the second side surface of the ceramic body 2, to the end of the green pile, which will form the fourth side surface of the ceramic body 2. The surfaces of the fourth internal electrode 16 and the third internal electrode 14, which face the cavity formed in this way, each form the fourth discharge zone 15 and third discharge zone 13 in the completed overvoltage protection element.

If necessary, further continuous green foils can be stacked on the stack formed up to now. The second internal electrode 11 is applied to the top of the stack that has now been formed. For example, according to the previous one, by screen printing. The second inner electrode 11 has the same profile as the third internal electrode 14.

One or more green sheets, which have a hole in the middle, are stacked on the stack formed in this way. The hole or the holes arranged next to one another will form the cavity of the first discharge vias 7 in the finished overvoltage protection element. A continuous green sheet is applied to the resulting stack. The first internal electrode 9 is applied to its underside, for example by screen printing.

Here, too, in the case of green foils filled with organic material and having a hole, the first internal electrode 9 can also be applied to the top of this green foil.

It runs from the side of the green sheet stack, which forms the first side surface in the finished ceramic body 2, to approximately the middle of the green sheet to which it is applied.

The cavity, which is delimited by the last-mentioned green sheets with a hole, by the green sheets with the second or first internal electrode (11 and 9) arranged below and above, is formed in the completed

The overvoltage protection element 1 is the first discharge via 7. The areas of the second inner electrode 11 and the first inner electrode 9 facing the cavity each form the second discharge zone 10 and the first discharge zone 8 in the completed overvoltage protection element 1.

If necessary, further continuous green foils can be applied above the stack formed in this way. The thickness of the respective green foils and the number of green foils stacked on top of one another can be selected to be adapted to the total height of the discharge vias and the overvoltage protection element to be achieved.

The green sheet stack thus formed is pressed to obtain a pressed green sheet stack. After the pressed green foil stack has been decarburized, for example at 600 ° C., the green foil stack is sintered.

During decarburization, among other things, the organic filler material of the green sheets with a hole can be expelled from the green sheet stack. The cavities of the discharge vias are formed in the process.

The sintering temperature can be selected as a function of the ceramic materials selected and the internal electrode materials that are matched to them. For example, for an LTCC material and copper electrodes, a sintering temperature in the range from 800 to 1200 ° C, more preferably from 800 to 1000 ° C can be used.

In other cases, for example with HTCC materials, a sintering temperature above 1200 ° C, for example up to 1800 ° C, can be used. In such a case, a material for the internal electrodes could include, for example, tungsten, tantalum or molybdenum.

The sintering takes place in an atmosphere which corresponds to the desired filling gas. Correspondingly, these gases can be sintered in a nitrogen, hydrogen, argon, neon or a corresponding mixed atmosphere. The pressure during sintering is preferably Normal pressure, but can be adjusted with regard to the breakdown voltage to be achieved. That is, the pressure can be above or below normal pressure.

The external contacts are applied to the ceramic body 2 sintered in this way. The external contacts can be applied by any method, such as burning in a metal-containing paste. The external contacts are applied in such a way that they are connected to the respective internal electrodes to be contacted.

FIG. 3 shows a second exemplary embodiment of an overvoltage protection element 1 in a schematic cross section.

The second exemplary embodiment can correspond to the structure of the first exemplary embodiment except for the shape of the second and third internal electrodes 11 and 14.

The schematic cross section shown in FIG. 3 thus corresponds to a cross-sectional direction C - D, as indicated in FIG. 1A.

In contrast to the first exemplary embodiment, in the second exemplary embodiment the internal electrodes (second internal electrode 11 and third internal electrode 14) connected to the ground contacts are not passed through the overvoltage protection element 1 or the ceramic body 2 in a feedthrough design.

In accordance with the second exemplary embodiment, the second internal electrode 11 connects the second discharge zone 10, which is arranged on the underside of the first discharge vias 7, exclusively to the first ground contact 4. Correspondingly, the third internal electrode 14 connects the third discharge zone 13, which is arranged on the upper side of the second discharge vias 12, exclusively to the second ground contact 6.

In an equivalent manner to the first internal electrode 9 and the fourth internal electrode 16, which are each connected to only one external contact, the second internal electrode 11 and third internal electrode 14 end inside the ceramic body.

Apart from this, the second internal electrode 11 and the third internal electrode 14 can have the same properties as the corresponding internal electrodes 11 and 14 in the first exemplary embodiment.

The manufacturing method also essentially corresponds to the manufacturing method which was explained in connection with the first exemplary embodiment. In a process based on the stacking of green foils, the green foils on which the second internal electrode 11 or the third internal electrode 14 is formed are provided with the second internal electrode 11 or the third internal electrode 14 only to such an extent that they do not come from one side of a green foil stack reach to the other side of the stack of green sheets. Both ends within the area of the respective green sheet, so that the second discharge zone 10 and the third discharge zone 13 are formed as described above.

FIG. 4 shows a third exemplary embodiment of the overvoltage protection element 1 in a schematic cross section. The third exemplary embodiment can basically correspond to the first or the second exemplary embodiment mentioned above, except for the following difference. Thus, in this third exemplary embodiment, the ceramic material 17 of the ceramic body 2, which delimits the first discharge via 7 (gas discharge via) and the second discharge via 12 (gas discharge via) horizontally, is doped with an ignition aid. For example, boron, strontium, tungsten or potassium can be used as an ignition aid dopant.

Doping with an ignition aid facilitates the ionization of the gas during an ESD event, that is, when an overvoltage is applied to a signal line contact 3 or 5. This makes it easier to derive the overvoltage from a signal line contact 3 or 5 via the corresponding gas-filled discharge via 7 or 12 to a ground contact 4 or 6.

In principle, the ignition aid can be contained exclusively as doping in the ceramic material 17 which forms the side walls of one of the cylindrical gas discharge vias 7 or 12.

The igniter can, however, also be introduced as doping in the entire ceramic material 17, which is located at the horizontal level of the respective discharge vias 7 or 12, as shown in FIG.

This simplifies the processing of a corresponding third exemplary embodiment when a green stack method is used. In principle, the green stack method can correspond to the method mentioned for the first or second exemplary embodiment, with the difference that the green foils, which contain a central hole for forming one of the discharge vias 7 or 12, are doped with the ignition aid. That is, the ceramic material 17 of the corresponding green sheets is doped with the ignition aid.

FIG. 5 shows schematic views of the top (FIG. 5A), the fourth side surface (FIG. 5B) and the first side surface (FIG. 5C) of a fourth exemplary embodiment of the overvoltage protection element 1.

In principle, the fourth exemplary embodiment can be identical to the first, second or third exemplary embodiment, with the exception of the following features.

In contrast to the previous exemplary embodiments, the first signal line contact 3 and the second signal line contact 5 are designed in the shape of a cap around the first side face and the third side face of the ceramic body 2, respectively.

That is, the first signal line contact 3 and the second signal line contact 5 each completely cover the first side surface and the third side surface. In addition, they expand to a certain extent onto the respective adjoining surfaces of the ceramic body 2.

Such a cap-shaped enclosure can facilitate the introduction by soldering into a circuit with conductor tracks to be protected. FIG. 6 shows a fifth exemplary embodiment of the overvoltage protection element 1 in a schematic cross section.

The fifth exemplary embodiment can be identical to one of the previously described exemplary embodiments of the overvoltage protection element, apart from the following differences.

In the fifth exemplary embodiment, a cavity 18 is formed in the ceramic body 2 between the first discharge zone 8 and the fourth discharge zone 15.

The cavity 18 is cylindrical, the first discharge zone 8 being formed on the upper side of the cavity 18 and the fourth discharge zone 15 being formed on the lower side of the cavity 18.

The cavity 18 is filled with a filling gas.

The first discharge zone 8 can be designed equivalent to the first discharge zone 8 in accordance with one of the exemplary embodiments described above.

The first discharge via 7 is formed between the first discharge zone 8 and the second discharge zone 10 in the cavity 18. This takes place in that free-standing areas of the second inner electrode 11 in the cavity 18 form the second discharge zone 10.

For example, the second internal electrode 11 can penetrate the cylindrical cavity 18 over its full cross-sectional area. However, the second inner electrode 11 can also only go a little way into the cylindrical cavity 18 protrude. The second internal electrode 11 can also be structured in the region which forms the second discharge zone 10. That is, the second discharge zone 10 can be porous, for example.

In an equivalent manner, the second discharge via 12 is formed between the third discharge zone 13, which is free in the cavity 18, and the fourth discharge zone 15. In particular, the fourth discharge zone 15 can correspond to the discharge zone 15 described above in the previous exemplary embodiments.

A gas-filled intermediate space 19 is formed between the second discharge zone 10 and the third discharge zone 13.

That is, the effective gas-filled volume corresponding to the fifth embodiment, which is located between the first internal electrode 9 and fourth internal electrode 16, is greater than, for example, in the first embodiment.

Correspondingly, the coupling of signals between first internal electrode 9 and fourth internal electrode 16 can be reduced to a greater extent, since the effective dielectric constant of the medium arranged between first internal electrode 9 and fourth internal electrode 16 is reduced.

The method for producing the fifth exemplary embodiment also corresponds to the method for one of the exemplary embodiments mentioned above.

For example, a method based on stacking green sheets can be used. However, for the formation of the cavity 18 only green sheets, which are a have a corresponding hole in the middle, stacked between the green sheets with the fourth internal electrode 16 and first internal electrode 9.

In this embodiment in particular, preference is given to using green sheets whose hole is filled with an organic filler material.

In this way, all internal electrodes or all discharge zones can be formed by screen printing processes, equivalent to the process described for exemplary embodiment 1.

Figure 7 shows a sixth embodiment of an overvoltage protection element.

The sixth exemplary embodiment corresponds to the fifth exemplary embodiment except for the following differences.

A further strip-shaped inner electrode 20 is arranged between the second inner electrode 11 and the third inner electrode 14. This fifth inner electrode 20 runs horizontally between the second inner electrode 11 and the third inner electrode 14 and preferably parallel and / or congruent with them. It therefore protrudes into the space 19 of the cylindrical cavity 18.

The fifth inner electrode 20 is connected to both the first ground contact 4 and the second ground contact 6. That is to say, it leads through the ceramic body 2 in a manner similar to that of the second internal electrode 11 or the third internal electrode 14 of the first exemplary embodiment. The dimensions of the fifth inner electrode 20 can be selected as desired. For example, the fifth internal electrode 19 can have the same width, that is to say extension in the direction of the length of the ceramic body 2, as the second internal electrode 11 and / or the third internal electrode 14.

The fifth inner electrode 20 can, however, also have a greater width.

The fifth inner electrode 20 can penetrate the cylindrical cavity 18 over its full cross-sectional area.

In combination with the features described above in relation to the width of the fifth inner electrode 20, the shielding between the first discharge zone 8 and the second discharge zone 15 can be improved by the fifth inner electrode 20.

The area of the fifth internal electrode 20 that is free in the cavity 18 can be planar.

The free-standing area in the cavity 18 can, however, also be structured, i.e. it can be porous or have structures which protrude into the cavity 18 in the direction of the first discharge vias 7 and / or the second discharge vias 12.

A correspondingly structured fifth inner electrode 20 can be particularly advantageous if the second inner electrode 11 and / or the third inner electrode 14 do not completely penetrate the cavity 18, that is to say only protrude into it a little. In this case, the fifth internal electrode 20 can supplement the second discharge zone 10 and / or the third discharge zone 13. That is, the effective area of the second discharge zone 10 and / or the third discharge zone 13 can thus be increased.

Such a fifth internal electrode 20 can be formed in the manufacturing process in accordance with the formation of the second internal electrode 11 and / or third internal electrode 14.

FIG. 8 shows a seventh exemplary embodiment of an overvoltage protection element 1. FIG. 8A shows a plan view of the top of the overvoltage protection element 1 or of the ceramic body 2.

FIG. 8B shows a side view of the fourth side face of the ceramic body 2.

The outer electrodes 3, 4, 5, 6 correspond to the

External electrodes 3, 4, 5, 6 of the first exemplary embodiment, it being possible for the dimensions of the external electrodes 3, 4, 5, 6 to differ.

FIG. 9 shows schematic cross sections of the seventh exemplary embodiment.

FIG. 9A shows a schematic cross section along the sectional plane identified by C - D in FIG. 8B, which runs parallel to the top of the ceramic body (2).

FIG. 9B shows a schematic cross section along the sectional plane identified by E - F in FIG. 8B, which runs parallel to the upper side of the ceramic body (2). FIG. 9C shows a schematic cross section along the sectional plane identified by A - B in FIG. 8A, which runs parallel to the first side face of the ceramic body (2).

As can be seen in FIG. 9C, the first unloading via 7 and the second unloading via 12 in the seventh exemplary embodiment are at the same horizontal height, that is to say they have no vertical offset.

As shown in FIG. 9A, the first internal electrode 9 connects the first discharge zone 8 exclusively to the first signal line contact 3.

The third internal electrode 14, which connects the third discharge zone 13 exclusively to the second ground contact 6, runs at the same height and perpendicular thereto.

As shown in FIG. 9B, the second internal electrode 11 connects the second discharge zone 10 exclusively to the first ground contact 4.

The fourth internal electrode 16, which connects the third discharge zone 15 exclusively to the second signal line contact 5, runs at the same height and perpendicular thereto.

Apart from these features, the seventh is

Embodiment is constructed equivalent to the first embodiment and can be produced equivalently. In this seventh exemplary embodiment, too, the discharge zones 8 and 15 connected to different signal line contacts are arranged on the sides of the two discharge vias 7 and 12 facing away from one another.

This increases the distance between the internal electrodes 9 and 16 connected to signal lines, although the discharge vias 7 and 12 are arranged at the same height.

For example, an overvoltage protection element 1 that is flatter in comparison to the other exemplary embodiments can be manufactured, the coupling being kept as low as possible at the same time.

Figure 10 shows an eighth embodiment of an overvoltage protection element 1. Figure 10A shows a top view of the top of the overvoltage protection element 1 or the ceramic body 2. Figure 10B shows a side view of the fourth side surface of the ceramic body 2 and Figure 10C shows a side view of the first Side surface of the ceramic body 2.

In the eighth exemplary embodiment, similar to the first exemplary embodiment, the first signal line contact 3 is formed on the first side surface of the ceramic body 2. The second signal line contact 5 is also correspondingly formed on the third side surface of the ceramic body. The respective signal line contacts 3 and 5 have a corresponding bracket-shaped design as the corresponding signal line contacts 3 and 5 in the first embodiment. The first ground contact 4 is arranged on the second side surface of the ceramic body 2. It has a similar clip-shaped structure as the ground contact 4 in the first exemplary embodiment. Opposite the first ground contact 4, a third ground contact 4 ′ is formed on the fourth side surface of the ceramic body 2. Both ground contacts 4 and 4 'preferably have the same dimensions and are correspondingly designed in a similar manner.

Furthermore, a second ground contact 6 is also formed on the second side surface of the ceramic body 2. This also has a clamp-like structure similar to the first ground contact 4. A fourth earth contact 6 ′ is arranged on the fourth side surface of the ceramic body 2 opposite the second earth contact 6. The fourth ground contact 6 'is again constructed in the form of a clamp.

Together, the first ground contact 4 and the third ground contact 4 'form a first pair of ground contacts. Correspondingly, the second ground contact 6 and the fourth ground contact 6 'form a second pair of ground contacts.

The first pair of ground contacts and the second pair of ground contacts are preferably arranged on the ceramic body 2 in such a way that a symmetrical arrangement with respect to the center of the ceramic body 2 is created.

FIG. 11 shows schematic cross sections through the eighth exemplary embodiment.

The schematic cross section according to FIG. 11A runs along the line AB, as indicated in FIG. 10A. The schematic cross section according to FIG. 11B runs along the line C - D, as indicated in FIG. 10B.

As shown in FIG. 10A, the first unloading via 7 and the second unloading via 12 have not only a vertical but also a horizontal offset.

In an equivalent manner to the first exemplary embodiment, the first discharge via 7 between the first discharge zone 8 and the second discharge zone 10 is designed as a gas discharge via.

The first discharge zone 8 is connected exclusively to the first signal line contact 3 via the first internal electrode 9. The properties of the first discharge zone 8 and the first internal electrode 9 correspond to those as described for the first discharge zone 8 and the first internal electrode 9 in accordance with the first exemplary embodiment.

FIG. 11B shows the course of the second internal electrode 11 through the ceramic body 2 in a schematic cross section.

The second internal electrode 11 is formed between the first ground contact 4 and the third ground contact 4 '. That is, the first ground contact 4 and the second ground contact 4 'are electrically coupled by the second internal electrode 11, whereby they form the first pair of ground contacts described above. In the exemplary embodiment 7, the second internal electrode 11 does not form any further electrical contacts to further external contacts. The second discharge zone 10 of the first discharge vias 7 is formed as part of the second internal electrode 11.

The second discharge via 12 is formed between the third discharge zone 13 and the fourth discharge zone 15. This is also a cylindrical gas discharge via.

The fourth discharge zone 15 is connected in an electrically conductive manner via the fourth internal electrode 16 exclusively to the second signal line contact 5. The shape or the properties of the fourth discharge zone 15 and the fourth internal electrode 16 can correspond to those of the fourth discharge zone 15 and the fourth internal electrode 16 of the first exemplary embodiment.

The third internal electrode 14 is designed similarly to the second internal electrode 11. It connects the third discharge zone 13 with the second ground contact 6 to the fourth ground contact 6 'and thus forms the second pair of ground contacts.

The third internal electrode 14 forms the third discharge zone 13 on the upper side of the second discharge vias 12.

As described above, such a design can have the advantage that the ground lines can be routed through the overvoltage protection element 1 in a feedthrough design. In the arrangement according to the eighth exemplary embodiment, however, the signal line contacts 3 and 5 can be protected from galvanically independent ground contact pairs by the corresponding discharge vias 7 and 12, respectively. The first and the second pair of ground contacts can each be connected to galvanically independent ground lines. A process for manufacturing the overvoltage protection element 1 in accordance with the eighth exemplary embodiment can in principle be equivalent to the manufacturing process in the first exemplary embodiment.

For example, a process based on stacking green sheets can be used. This can differ from the manufacturing process of the first exemplary embodiment by the following features:

Green films which have a hole for forming the second discharge vias 12 do not have to have the hole in the center of the green film, but rather offset in the direction of the side which will form the third side surface of the ceramic body 2.

Correspondingly, green foils which have a hole for forming the first discharge vias 7 do not have to have the hole in the center of the green foil, but rather offset in the direction of the side which will form the first side surface of the ceramic body 2.

If necessary, the same green sheets with holes can be used for the first discharge via 7 as for the second discharge via 12, the green sheets for the first discharge via 7 being rotated by 180 ° with respect to those for the second discharge via 12.

The first internal electrode 9 or the fourth internal electrode 16 can also be designed in such a way that it does not extend as far as the center of the ceramic body 2, corresponding to the illustration in FIG. 11A. The first internal electrode 9 is formed at least up to the first discharge zone 8, but can protrude beyond this into the ceramic body 2 as long as it ends within the ceramic body 2. The fourth internal electrode 16 is correspondingly formed at least up to the fourth discharge zone 15, but can protrude beyond this into the ceramic body 2 as long as it ends within the ceramic body 2.

The additional ground contacts compared to the first exemplary embodiment can also be attached to the ceramic body 2 in a manner corresponding to the other external contacts.

FIG. 12 shows, in schematic views, a ninth exemplary embodiment of the overvoltage protection element.

FIG. 12A shows a plan view of the corresponding overvoltage protection element 1.

FIG. 12B shows a side view of the fourth side face of the overvoltage protection element 1.

FIG. 12C shows a view of the first side face of the overvoltage protection element 1.

In the ninth exemplary embodiment, a first ground contact 4 is arranged on the first side surface of the ceramic body 2. Similar to the first signal line contact 3 in the eighth exemplary embodiment, it is designed in the form of a clamp.

Opposite the first ground contact 4, the second ground contact 6 is on the third side surface of the ceramic Body 2 arranged. The second ground contact 6 is also designed in the form of a clamp, similar to the first ground contact 4. The dimensions of the first ground contact 4 and the second ground contact 6 do not have to be identical, but they are preferably.

A first signal line contact 3 is arranged on the second side surface of the ceramic body 2.

A third signal line contact 3 ′ is arranged on the fourth side surface of the ceramic body 2 opposite the first signal line contact 3. Together, the first signal line contact 3 and the second signal line contact 3 'form the first signal line contact pair.

The second signal line contact 5 is arranged on the second side surface of the ceramic body 2 next to the first signal line contact 3.

Opposite the second signal line contact 5, the fourth signal line contact 5 'is arranged on the fourth side surface of the ceramic body 2. Together, the second signal line contact 5 and the fourth signal line contact 5 'form the second signal line contact pair.

The respective ground contacts 4 and 6 are preferably formed centrally on the respective side surfaces.

The first and the second signal line contact pair are preferably arranged on the ceramic body 2 in such a way that a symmetrical arrangement with respect to the center of the ceramic body 2 is created. The first signal line contact 3, the second signal line contact 5, the third signal line contact 3 'and the fourth signal line contact 5' are also designed in the shape of a clamp.

Since the ceramic body 2 is cuboid according to the ninth exemplary embodiment, the indication of the direction in terms of length, height and depth can be made in accordance with the definition of the first exemplary embodiment.

Consequently, it is preferred that the first signal line contact 3 and the second signal line contact 5 each have the same distance from the center of the second side surface of the ceramic body 2. This applies accordingly to the opposite signal line contacts 3 'and 5' in relation to the fourth side surface of the ceramic body.

FIG. 13 shows schematic cross sections of the ninth exemplary embodiment of the overvoltage protection element.

FIG. 13A shows a schematic cross section along the sectional plane E - F indicated in FIG. 12B. The cross section is thus parallel to the upper side of the ceramic body 2.

FIG. 13B shows a schematic cross section along the sectional plane AB indicated in FIG. 12A. The cross section is thus parallel to the fourth side face of the ceramic body 2. FIG. 13A shows the course of the first internal electrode 9 through the ceramic body 2. The first internal electrode 9 connects the first discharge zone 8 to the first signal line contact 3 and to the third signal line contact 3 '. This forms the first pair of signal line contacts.

That is, a feedthrough arrangement is formed.

For example, a first high-frequency data line can be routed to the first signal line contact 3, passed through the ceramic body via the first internal electrode 9, and routed from the overvoltage protection element back to an external line via the third signal line contact 3 '.

The first internal electrode 9 thus connects the two contacts of the first signal line contact pair with the first discharge zone 8 of the first discharge vias 7, whereby, for example, a first high-frequency data line can be protected.

The first discharge zone 8 can be designed to be equivalent to the first discharge zone 8 in accordance with the first exemplary embodiment of an overvoltage protection element.

As shown in FIG. 13B, the second internal electrode 11 connects the second discharge zone 10 of the first discharge vias 7 exclusively to the first ground contact 4. Of the signal line contacts 3 and 5, the clip-shaped areas protruding over the top and bottom of the ceramic body are also shown.

According to the preceding explanations, all internal electrodes of the ninth exemplary embodiment are constructed in the form of strips and each run parallel to the The plane that is defined by the top of the ceramic body 2.

The first internal electrode 9 and the second internal electrode 11, which are arranged on the first discharge via 7, are oriented perpendicular to one another.

The second unloading via 12 is constructed similarly to the first unloading via 7. Correspondingly, the discharge zones arranged on the second discharge via 12 and the internal electrodes connected to them are constructed similarly to those arranged on the first discharge via 7.

The third inner electrode 14 connects the third discharge zone 13, which is arranged on the upper side of the second discharge vias, exclusively to the second ground contact 6.

The fourth discharge zone 15, which is arranged on the underside of the second discharge vias 12, is connected via the fourth internal electrode 16 to both the second signal line contact 5 and the fourth signal line contact 5 ′. That is to say, the fourth internal electrode 16 connects the second signal line contact 5 to the fourth signal line contact 5 'in a feedthrough design. It forms the second pair of signal line contacts.

For example, a second high-frequency data line can be routed through the ceramic body 2 via the second pair of signal line contacts and the fourth internal electrode 16. Corresponding to the exemplary embodiments described above, the discharge vias in the eighth exemplary embodiment are also cylinder-shaped gas discharge vias.

As already described in the introduction, an overvoltage protection element 1 according to the invention can also be designed in a feedthrough design, for example in accordance with the ninth exemplary embodiment.

The feedthrough design can save space when installing it in an electronic circuit.

Due to the horizontal as well as vertical offset of the first inner electrode 9 and the fourth inner electrode 16, the decoupling of the signals can be improved compared to the prior art described in the introduction.

A manufacturing method for the ninth exemplary embodiment can essentially correspond to the manufacturing method as described for the first or the further exemplary embodiments.

For example, green sheets which have a hole for forming the second discharge vias 12 do not have to have the hole in the center of the green sheet, but rather offset in the direction of the side which will form the third side surface of the ceramic body 2. Accordingly, green sheets which have a hole for forming the first discharge vias 7 do not have to have the hole in the center of the green sheet, but rather offset in the direction of the side which will form the first side surface of the ceramic body 2.

If necessary, the same green sheets with holes can be used for the formation of the first Entaldevia 7 and the second Entaldevia 12, the green sheets for the first Entaldevia 7 being used rotated by 180 ° to those for the second Entaldevia 12.

The second internal electrode 11 or the third internal electrode 14 cannot be formed up to the center of the ceramic body 2, in accordance with the illustration in FIG. 13B.

The second internal electrode 11 is formed at least up to the second discharge zone 10, but can protrude beyond this into the ceramic body 2 as long as it ends within the ceramic body 2. Correspondingly, the third internal electrode 14 is formed at least up to the third discharge zone 13, but can protrude beyond this into the ceramic body 2 as long as it ends within the ceramic body 2.

Furthermore, the first internal electrode 9 and the fourth internal electrode 16 must be formed on the respective green sheets so that they extend from the side of the green sheet stack, which will form the second side surface of the ceramic body, to the side of the green sheet stack, which is the fourth side surface of the ceramic body form will extend. The signal line contacts which are further compared to the first exemplary embodiment can also be attached to the ceramic body 2 in a manner corresponding to the other external contacts.

FIG. 14 shows a tenth exemplary embodiment of an overvoltage protection element 1 in schematic cross sections.

The tenth exemplary embodiment of the overvoltage protection element 1 largely corresponds to the ninth exemplary embodiment of an overvoltage protection element 1. In addition to the components of the ninth exemplary embodiment shown in FIG. 13 and described in connection with FIG. 13, the tenth exemplary embodiment has a decoupling cavity 21.

FIG. 14A shows a schematic cross section corresponding to the schematic cross section which was shown in FIG. 13B.

The decoupling cavity 21 is preferably formed symmetrically in the center of the cuboid ceramic body.

In the tenth embodiment, the decoupling cavity 21 itself is cuboid. It is located on the horizontal plane in the middle between the first unloading via 7 and the second unloading via 12.

The expansion of the decoupling cavity 21 in the direction of the length of the ceramic body 2 preferably corresponds at most to the horizontal distance between the internal electrodes arranged on the first discharge via 7 and the internal electrodes arranged on the second discharge via 12. As indicated in FIG. 14A, however, the extent of the decoupling cavity 21 in the longitudinal direction of the ceramic body 2 can also be significantly smaller than the distance described above.

In order to improve the efficiency of the decoupling effect of the decoupling cavity 21, the height of the decoupling cavity 21 should at least correspond to the vertical distance between the first discharge zone 8 and the fourth discharge zone 15. As indicated in FIGS. 14A and B, the height of the decoupling cavity 21 can, however, also be greater than this distance.

The dimensions of the decoupling cavity 21 are preferably chosen so that in projections of the first inner electrode 9, the first discharge vias 7, the fourth inner electrode 16 and the second discharge vias 12 on the first side surface and the projection of the decoupling cavity 21 on the first side surface, the projection surfaces of the discharge vias formed and said internal electrodes are as far as possible within the projection surface of the decoupling cavity 21.

In principle, it is possible for the decoupling cavity 21 to completely penetrate the ceramic body in the direction of the depth of the ceramic body 2. This means that the decoupling cavity 21 can be designed to be open to the atmosphere on the second side surface and on the fourth side surface (not shown).

However, as shown in FIG. 14B, for reasons of the stability of the overvoltage protection element 1, the The decoupling cavity 21 is formed entirely within the ceramic body 2, which means that the decoupling cavity 21 is delimited on all sides by the ceramic material of the ceramic body 2.

Basically, the decoupling cavity 21 is filled with a filling gas. In the case of a decoupling cavity 21 open to one or more sides, the filling gas is air. In the case of a closed decoupling cavity 21, the filling gas preferably corresponds to the filling gas of the gas discharge vias.

A manufacturing process of the tenth exemplary embodiment can be essentially identical to the manufacturing process of the ninth exemplary embodiment.

However, some green sheets which form the green sheet stack must have a further cutout in the middle to form the decoupling cavity 21. The recess can be made in a similar way to the holes for the discharge vias.

For example, one or more green sheets can be stacked on top of one another without a gap. One or more green sheets, which contain a cutout for forming the decoupling cavity 21, can be stacked on this. For the second unloading via 12, one or more green sheets, which contain both a cutout for the decoupling cavity 21 and also contain holes for the second unloading via 12, can be stacked on the stack formed in this way. Further green sheets (one or more), which contain further cutouts for the decoupling cavity 21, can be stacked on the correspondingly formed stack. More green sheets, which both have a recess for the decoupling cavity 21 as well as holes for the first unloading via 7 can be stacked on the stack thus formed. Finally, one or more continuous green sheets are stacked on the stack formed in this way. The electrodes can be introduced in accordance with the method described above in relation to the ninth exemplary embodiment or the first exemplary embodiment.

The hole in green sheets for forming the decoupling cavity 21 can also be filled with an organic filler material in order to improve the stability during the process.

FIG. 15 shows an eleventh exemplary embodiment of an overvoltage protection element 1 in a schematic cross section.

The cross section shown in Figure 15 is equivalent to the cross section shown in Figure 14B.

The eleventh exemplary embodiment corresponds essentially to the tenth exemplary embodiment. The only difference is the shape of the decoupling cavity 21.

In contrast to what is shown in FIG. 14B for the tenth exemplary embodiment, the decoupling cavity 21 in the eleventh exemplary embodiment can have a non-cuboid shape. For example, the shape deviating from the cuboid shape can have rounded corners or beveled corners.

Such an embodiment can increase the stability of the ceramic body 2 or of the overvoltage protection element 1, since the thickness of the ceramic material or of the ceramic body 2 in the area of the corners at the level of the decoupling cavity 21 is larger.

A method for producing the eleventh exemplary embodiment can be carried out in accordance with the method as described with reference to the tenth exemplary embodiment.

The sizes of the recesses in the green sheets to be stacked, which form the ceramic body with the decoupling cavity 21, must be adapted in accordance with the desired shape.

Figure 16 shows a twelfth embodiment of the present invention.

FIG. 16A shows a schematic plan view of the upper side of the ceramic body 2 and FIG. 16B shows a schematic side view of the fourth side surface of the ceramic body 2.

The twelfth exemplary embodiment can be understood as an extension of the principle corresponding to the ninth exemplary embodiment to a multiplicity of signal line contacts or signal line contact pairs.

The twelfth exemplary embodiment thus has a first ground contact 4 and a second ground contact 6 equivalent to the ninth exemplary embodiment.

Similar to the ninth exemplary embodiment, the twelfth exemplary embodiment also has a first signal line contact pair, formed from the first signal line contact 3 and the third signal line contact 3 ′ and a second Signal line contact pair, formed from the second signal line contact 5 and the fourth signal line contact 5 '.

In addition, a third signal line contact pair and a fourth signal line contact pair are arranged between the first signal line contact pair and the second signal line contact pair.

The third pair of signal line contacts is arranged adjacent to the first pair of signal line contacts and is formed from a fifth signal line contact 22 and the seventh signal line contact 22 ′.

The fourth pair of signal line contacts is arranged adjacent to the second pair of signal line contacts and is formed from a sixth signal line contact 23 and an eighth signal line contact 23 ′.

All signal line contacts are similar, for example designed in accordance with the signal line contacts of the ninth embodiment.

Equivalent to the description of the ninth exemplary embodiment, a signal can be applied to each of the four signal line contact pairs or a signal line can be connected.

The four signal line contact pairs preferably have a uniform arrangement in the direction of the length of the ceramic body 2. FIG. 16C shows a schematic cross section of the twelfth exemplary embodiment along the line AB indicated in FIG. 16A

Equivalent to the ninth exemplary embodiment, a first signal line, which is routed via the first pair of signal line contacts, can be protected against overvoltages with respect to the first ground contact 4 via the first discharge via 7.

Correspondingly, a second signal line, which is routed via the second signal line contact pair, can also be protected against overvoltages with respect to the second ground contact 6 via the second discharge via 12, in equivalence to the ninth exemplary embodiment.

A third signal line, which on the third

Signal line contact pair is connected, is protected against overvoltages via the third discharge via 12 'with respect to the second ground contact 6.

The third unload via 12 'is designed to be equivalent to the second unload via 12 and is similarly contacted. The third unloading via 12 ′ is horizontally offset and arranged below the first unloading via 7.

The fifth discharge zone 13 ′ is arranged on the upper side of the third discharge vias 12 ′ and is connected exclusively to the second ground contact 6 via the sixth internal electrode 14 ′.

The sixth discharge zone 15 'is arranged on the underside of the third discharge vias 12' and over the seventh internal electrode 16 'connected to both the fifth signal line contact 22 and the seventh signal line contact 22'.

Thus, the first internal electrode 9 of the first pair of signal line contacts and the seventh internal electrode 16 'of the third pair of signal line contacts, which is adjacent in the longitudinal direction of the ceramic body, have the maximum possible relative distance from one another. This reduces the coupling between adjacent signal lines that are routed through the component.

In addition, the second internal electrode 11 and the seventh internal electrode 14 'face one another, which helps to decouple the signals on the first internal electrode 9 and seventh internal electrode 16'.

In addition, the second inner electrode 11 and the seventh inner electrode 14 'can be contacted via galvanically independent ground lines.

The local structure, the local arrangement or the local contacting of the adjacent discharge vias 7 and 12 'of the present exemplary embodiment is thus similar to the structure, the arrangement or the contacting of the discharge vias 7 and 12 in the ninth exemplary embodiment.

The same applies to the overvoltage protection of the second signal line contact pair and the fourth signal line contact pair adjacent thereto.

A fourth signal line, which on the fourth

Signal line contact pair is connected via the fourth Entladevia 7 'with respect to the first ground contact 4 protected against overvoltages.

The fourth unloading via 7 'is designed to be equivalent to the first unloading via 7 and is similarly contacted. The fourth discharge via 7 ′ is offset and arranged above the second discharge via 12.

The seventh discharge zone 8 'is arranged on the upper side of the fourth discharge vias 7' and is connected to both the sixth signal line contact 23 and the eighth signal line contact 23 'via the eighth internal electrode 9'.

The eighth discharge zone 10 'is arranged on the underside of the fourth discharge vias 7' and is connected exclusively to the first ground contact 4 via the ninth internal electrode 11 '.

The eighth internal electrode 9 ′ of the fourth signal line contact pair and the fourth internal electrode 16 of the second signal line contact pair, which is adjacent in the longitudinal direction of the ceramic body, thus have the maximum possible relative distance from one another. This reduces the coupling between adjacent signal lines that are routed through the component.

In addition, the ninth internal electrode 11 ′ and the third internal electrode 14 ′ face one another, which helps to decouple the signals on the eighth internal electrode 9 ′ and the fourth internal electrode 16.

In addition, the second inner electrode 11 and the seventh inner electrode 14 'can be contacted via galvanically independent ground lines. As shown in FIG. 16C, the vertical arrangement (direction from the top to the bottom of the ceramic body 2) of the discharge vias is as follows: the fourth discharge via 7 'is above the

- First discharge vias 7, which is above the second discharge vias 12, which is above the

- third unloading vias 12 '. This arrangement also makes the distance between the eighth

Inner electrode 9 'of the fourth signal line contact pair and the seventh inner electrode 16' of the third signal line contact pair as large as possible, since the discharge zones formed by these electrodes are on opposite sides of the respective discharge vias.

In principle, the structure according to the twelfth exemplary embodiment can be implemented with any number of signal line contact pairs, which are always connected to a discharge via such that the discharge zones of adjacent signal line contact pairs are always facing away from one another.

List of reference symbols:

1 overvoltage protection element

2 ceramic body

3 first signal line contact

3 'third signal line contact

4 first ground contact

4 'third ground contact

5 second signal line contact

5 'fourth signal line contact

6 second ground contact

6 'fourth ground contact

7 first unloading via

7 'fourth unloading via

8 first unloading zone

8 'seventh unloading zone

9 first inner electrode

9 'eighth inner electrode

10 second unloading zone

10 'eighth unloading zone

11 second inner electrode 11 'ninth inner electrode

12 second unloading via

12 'third unloading via

13 third unloading zone 13 'fifth unloading zone

14 third inner electrode

14 'sixth inner electrode

15 fourth unloading zone

15 'sixth unloading zone

16 fourth inner electrode 16 'seventh inner electrode

17 ceramic material doped with ignition aid 18 cavity

19 space

20 fifth inner electrode

21 decoupling cavity

Claims

1. Overvoltage protection element (1) comprising a ceramic body (2), at least one first discharge via (7) and a second discharge via (12), wherein

- the first discharge via (7) is formed between a first discharge zone (8) on the upper side of the first discharge via (7) and a second discharge zone (10) on the underside of the first discharge via (7),

- The second discharge via (12) is formed between a third discharge zone (13) on the upper side of the second discharge via (12) and a fourth discharge zone (15) on the underside of the second discharge via (12),

- the first discharge zone (8) is connected to a first external contact via a first internal electrode (9),

- the second discharge zone (10) is connected to a second external contact via a second internal electrode (11),

- The third discharge zone (13) is connected to a third external contact via a third internal electrode (14), and

- The fourth discharge zone (15) is connected to a fourth external contact via a fourth internal electrode (16).

2. Surge protection element (1) according to claim 1, wherein the first Entladevia (7) vertically above the second

Entladevia (12) is arranged.

3. Overvoltage protection element (1) according to one of the claims

1 and 2, where - the first external contact is a first signal line contact (3),

- The second external contact is a first ground contact (4) and

- The first inner electrode (9) connects the first discharge zone (8) exclusively to the first signal line contact.

4. Surge protection element (1) according to claim 3, wherein

- the third external contact is a second ground contact (6),

- The fourth external contact is a second signal line contact (5) and

- The fourth inner electrode (16) connects the fourth discharge zone (15) exclusively to the second signal line contact (5).

5. Surge protection element (1) according to claim 4, wherein

- The second inner electrode (11) connects the second discharge zone (10) exclusively to the first ground contact (4) and

- The third inner electrode (14) connects the third discharge zone (13) exclusively to the second ground contact (6).

6. Surge protection element (1) according to claim 4, wherein

- the second inner electrode (11) connects the second discharge zone (10) to both the first ground contact (4) and the second ground contact (6),

- The third inner electrode (14) connects the third discharge zone (10) to both the first ground contact (4) and the second ground contact (6).

7. Overvoltage protection element (1) according to one of the claims

4 to 6, where

- an upper side of the ceramic body (2) is that outer surface of the ceramic body (2) which is arranged above the first discharge zone (8) and is closer to this first discharge zone (8) than all other discharge zones,

- an underside of the ceramic body (2) is an outer surface of the ceramic body (2) opposite the top,

- A first, a second, a third and a fourth side surface are the further outer surfaces of the ceramic body (2),

- the first signal line contact (3) is formed on the first side surface,

- The second signal line contact (5) is formed on the third side surface which is opposite the first side surface,

- The first ground contact (4) is formed on the second side surface, and

- The second ground contact (6) is formed on the fourth side face, which is opposite the second side face.

8. Overvoltage protection element (1) according to claim 7, wherein

- all internal electrodes (9, 11, 14, 16) are constructed in the form of strips and each run in a plane parallel to the top of the ceramic body (2),

- the first inner electrode (9) is aligned orthogonally to the first side surface,

- the second inner electrode (11) is aligned orthogonally to the second side surface, - The third inner electrode (14) is aligned orthogonally to the third side surface and

- The fourth inner electrode (16) is aligned orthogonally to the fourth side surface.

9. Surge protection element (1) according to one of claims 1-8, wherein the first Entladevia (7) and the second Entladevia (12) have no horizontal offset.

10. Overvoltage protection element (1) after) after one of the

Claims 1-8, wherein the first unloading via (7) is arranged horizontally next to the second unloading via (12).

11. Surge protection element (1) according to claim 9, wherein

- A cavity (18) is formed between the first discharge zone (8) and the fourth discharge zone (15),

- The second discharge zone (10) are formed by areas of the second inner electrode (11) that are free in the cavity (18),

- The third discharge zone (13) are formed by areas of the third internal electrode (14) that are free in the cavity (18) and

- The cavity (18) is filled with a filling gas.

12. Surge protection element according to claim 11, wherein

- At least one fifth inner electrode (20) is connected to at least one ground contact,

- the fifth inner electrode (20) is aligned orthogonally to the second side surface of the ceramic body (2),

- The fifth inner electrode (20) is arranged between the second inner electrode (11) and the third inner electrode (13) and - The fifth inner electrode (20) has a free-standing area in the cavity (18).

13. Overvoltage protection element (1) according to one of the

Claims 7-12, wherein

- The first signal line contact (3) encloses the first side surface in the shape of a cap and

- The second signal line contact (5) encloses the third side surface in the shape of a cap.

14. Surge protection element (1) according to claim 4, wherein

- an underside of the ceramic body is an outer surface of the ceramic body (2) opposite the upper side,

- the first signal line contact (3) is formed on the first side surface,

- the first ground contact (4) and the second ground contact (6) are formed on the second side surface,

- A third ground contact (4 ') is formed on the fourth side surface, directly opposite the first ground contact (4), - A fourth ground contact (6 ') is formed on the fourth side surface, directly opposite the second ground contact (6),

- the second inner electrode (11) connects the second discharge zone (10) to both the first ground contact (4) and the third ground contact (4 '),

- The third inner electrode (14) connects the third discharge zone (13) to both the second ground contact (6) and the fourth ground contact (6 ').

15. Overvoltage protection element (1) according to one of the

Claims 1 and 2, wherein

- The second external contact is a first ground contact (4) which is arranged on the first side surface of the ceramic body (2),

- The third external contact is a second ground contact (6) which is arranged on the third side surface of the ceramic body (2) which is opposite the first side surface,

- the first external contact is a first signal line contact (3) which is arranged on the second side surface of the ceramic body (2), - the fourth external contact (5) is a second signal line contact which is arranged on the second side surface of the ceramic body (2),

- A third signal line contact (3 ') is formed on the fourth side surface directly opposite the first signal line contact (3),

- A fourth signal line contact (5 ') is formed on the fourth side surface directly opposite the second signal line contact (5),

- the first inner electrode (9) connects the first discharge zone (8) to both the first signal line contact (3) and the third signal line contact (3 '),

- The fourth inner electrode (16) connects the fourth discharge zone (15) to both the second signal line contact (5) and the fourth signal line contact (5 ').

16. Overvoltage protection element (1) according to claim 15, wherein

- the second inner electrode (11) connects the second discharge zone (10) exclusively to the first ground contact (4),

- the third inner electrode (14) connects the third discharge zone (13) exclusively to the second ground contact (6),

- A decoupling cavity (21) filled with filling gas is formed between the first unloading via (7) and the second unloading via (12).

17. Overvoltage protection element (1) according to claim 15, wherein

- a third unloading via (12 ') between a fifth unloading zone (13') on the top of the third unloading via (12 ') and a sixth unloading zone (15') is formed on the underside of the third discharge vias (12 '),

- A fourth discharge via (7 ') is formed between a seventh discharge zone (8') on the top of the fourth discharge via (7 ') and an eighth discharge zone (10') on the underside of the fourth discharge via (7 '),

- the fifth discharge zone (13 ') is connected exclusively to the second ground contact (6) via a sixth internal electrode (14'),

- the sixth discharge zone (15 ') is connected via a seventh internal electrode (16') to both a fifth signal line contact (22) and a seventh signal line contact (22 '),

- the seventh discharge zone (8 ') is connected to both a sixth signal line contact (22) and an eighth signal line contact (22') via an eighth internal electrode (9 '),

- the eighth discharge zone (10 ') is connected exclusively to the first ground contact (4) via a ninth internal electrode (11'),

- The fifth signal line contact (22) are arranged directly next to the first signal line contact (3) and together with the sixth signal line contact (23) between the first signal line contact (3) and the second signal line contact (5) on the second side surface of the ceramic body (2) , and

- The seventh signal line contact (22 ') is arranged on the fourth side surface of the ceramic body (2) opposite the fifth signal line contact (22), and

- The eighth signal line contact (23 ') is arranged on the fourth side surface of the ceramic body (2) opposite the sixth signal line contact (23).

18. Overvoltage protection element (1) according to claim 17, wherein the two discharge zones of two directly adjacent discharge vias, which are electrically connected to one signal line contact that is electrically independent of the other signal line contacts, are arranged on opposite sides of the respective discharge vias.

19. Overvoltage protection element (1) according to one of claims 1-18, wherein

- The first discharge via (7) is designed as a cavity filled with filling gas between the first discharge zone (8) and the second discharge zone (10)

- The second discharge via (12) is designed as a cavity filled with filling gas between the third discharge zone (13) and the fourth discharge zone (15).

20. Overvoltage protection element (1) according to claim 19, wherein a ceramic material (17) of the ceramic body (2) which is adjacent to the first Entladevia (7) and / or the second Entladevia (12) is doped with an ignition aid.

21. Overvoltage protection element (1) according to claim 20, wherein the ignition aid comprises at least one element selected from the following group consisting of B, Sr, W, K.

22. Overvoltage protection element (1) according to one of claims 1-21, wherein the ceramic body (2) is cuboid.

23. Overvoltage protection element (1) according to one of claims 1-22, wherein the ceramic body (2) is a is a laminated multi-layer body and the top and bottom each designate two opposite sides of an object in the lamination direction. 24. Overvoltage protection element (1) according to one of the

Claims 1-22, wherein the first internal electrode is flat and defines a horizontal plane.