Method for producing an electric component and electric component

Abstract

A method for producing an electric component (19) is specified, wherein in a step A) a body (1) having at least one cavity (7, 8) is provided. In a step B), the cavity (7, 8) is at least partly filled with a liquid insulation material (13) by means of capillary forces. Furthermore, an electric component (19) is specified wherein a cavity (7, 8) is at least partly filled with an insulation material (13). The insulation material (13) is introduced into the cavity (7, 8) by means of capillary forces. Furthermore, an electric component (19) is specified wherein a cavity (7, 8) is at least partly filled with an organic insulation material (13) and wherein the cavity is at least partly covered by a fired external contacting (17, 18).

Claims

1. A method for producing an electric component comprising the following steps: A) providing a body having at least one cavity; and B) at least partly filling the cavity with an insulation material by means of capillary forces, wherein the body is introduced into the insulation material only by one of the side surfaces of the body and the insulation material then migrates into the cavity on account of capillary forces.

2. The method according to claim 1, wherein the cavity is etched into the body.

3. The method according to claim 1, wherein before step B) external contacting is applied to the body.

4. The method according to claim 3, wherein the external contact-connection at least partly covers the cavity.

5. The method according to claim 1, wherein after step B) external contacting is applied to the body.

6. The method according to claim 3, wherein the external contacting is fired.

7. The method according to claim 1, wherein the insulation material comprises lacquer or glass.

8. The method according to claim 1, wherein the body has at least one electrode layer and wherein the cavity adjoins the electrode layer.

9. The method according to claim 1, wherein the body has at least one electrode layer and wherein after step B) the insulation material covers at least one end of the electrode layer.

10. The method according to claim 1, wherein the cavity does not adjoin an electrode layer.

11. The method according to claim 1, wherein parts of the body are covered before step B).

12. The method according to claim 1, wherein the body is separated into a plurality of main bodies for electric components after step B).

13. The method according to claim 1, wherein the body has cavities on different side surfaces and wherein the insulation material is introduced into the cavities on the different side surfaces in a single-stage method.

14. The method according to claim 1, wherein the body is introduced at least partly into the liquid insulation material in step B).

Description

(1) The subjects described here are explained in greater detail below on the basis of schematic exemplary embodiments which are not true to scale.

(2) In the figures:

(3) FIG. 1 shows a body for a multilayer component in a schematic perspective view,

(4) FIG. 2 shows in schematic illustration the step of introducing insulation material into cavities of the body from FIG. 1,

(5) FIG. 3 shows a lateral plan view of the body from FIG. 1 before the introduction of insulation material in accordance with a first method sequence,

(6) FIG. 4 shows a lateral plan view of the body from FIG. 3 after the introduction of insulation material in accordance with the first method sequence,

(7) FIG. 5 shows a lateral plan view of the body from FIG. 4 after the application of external electrodes in accordance with the first method sequence,

(8) FIG. 6 shows a lateral plan view of the body from FIG. 1 before the introduction of insulation material in accordance with the second method sequence,

(9) FIG. 7 shows a lateral plan view of the body from FIG. 6 after the application of external contactings in accordance with the second method sequence,

(10) FIG. 8 shows a lateral plan view of the body from FIG. 7 after the introduction of insulation material in accordance with the second method sequence.

(11) Preferably, in the following figures, identical reference signs refer to functionally or structurally corresponding parts of the different embodiments.

(12) FIG. 1 shows a schematic perspective view of a body 1 for an electric component.

(13) The body 1 has a stack composed of dielectric layers 2 and electrode layers 3, 4 arranged there between. The layers 2, 3, 4 are stacked one above another along a stacking direction S. The stacking direction S corresponds to the longitudinal axis of the body 1.

(14) The body 1 depicted here is a main body for a component, for example for a piezoactuator. In a different embodiment, the body is separated into a plurality of main bodies in a later method step.

(15) The dielectric layers 2 contain a ceramic material, for example. Preferably, the dielectric layers 2 are embodied as piezoelectric layers, in particular as piezoceramic layers.

(16) The body 1 depicted is preferably a sintered body. Particularly preferably, the body 1 is a monolithic sintering body, such that the electrode layers 3, 4 are sintered jointly with the dielectric layers 2.

(17) The electrode layers 3, 4 preferably contain a metal. Particularly preferably, the electrode layers 3, contain copper or consist of copper. In further embodiments, the electrode layers 3, 4 can contain silver or silver-palladium, for example.

(18) The electrode layers 3, 4 comprise first electrode layers 3 and second electrode layers 4, which are arranged alternately one above another. The first electrode layers 3 extend as far as a first side surface 5 of the body 1 and are spaced apart from a second, opposite side surface 6. The second electrode layers 4 are spaced apart from the first side surface 5 of the body 1 and extend as far as the second, opposite side surface 6.

(19) First and second cavities 7, 8 are formed in the body 1 in a manner adjoining the electrode layers 3, 4, by means of which cavities the electrode layers 3, 4 are set back alternately from the side surfaces 5, 6. The cavities 7, 8 extend for example 100 m into the interior of the body 1.

(20) The first and second cavities 7, 8 form first and second insulation zones 9, 10, which electrically insulate the electrode layers 3, 4 in each case from a side surface 5, 6. In this way, the first electrode layers 3 can be jointly contacted by an external electrode 17 applied to the first side surface 5, while the second electrode layers 4 are insulated from said external electrode 17. Accordingly, the second electrode layers 4 can be electrically contacted by an external electrode 18 applied to the second side surface 6 (see FIG. 5). The first external electrode 17 is depicted by dashed lines in order to illustrate one possible positioning and configuration of the external electrode 17. The external electrodes 17, 18 can be applied before or after the filling of the cavities 7, 8 with insulation material.

(21) The cavities 7, 8 can additionally form predetermined breaking regions in which cracks arise and are guided in a targeted manner in the body 1. As a result, it is possible to prevent a crack from propagating in the body 1 in an uncontrolled manner and from leading to a short circuit in the event of bridging electrode layers 3, 4. Furthermore, the cavities 7, 8 can also lead to a mechanical load relief in the insulating zones 9, 10, such that fewer cracks arise in the body 1.

(22) In a different embodiment, the cavities 7, 8 can be positioned in such a way that they do not adjoin electrode layers 3,4. In this case, the cavities 7, 8 can serve only for mechanical load relief or as predetermined breaking regions.

(23) By way of example, the cavities 7, 8 are etched into the body 1. Such cavities 7, 8 have for example a slot width in the stacking direction of approximately 2 m.

(24) When a voltage is applied to the electrode layers 3, 4 via external contact-connections 17, 18 applied to the side surfaces 5, 6, an undesired electric breakdown can occur between an exposed electrode end 11, 12 and an external contact-connection 18, 17 which is not connected to the associated electrode layer 3, 4.

(25) The introduction of insulation material into the cavities 7, 8 is intended to increase the electric breakdown voltage and thus to prevent a breakdown. By way of example, the insulation material is applied at least to the electrode ends 11, 12. The work function of electrons from the electrode ends 11, 12 can thus be increased. Alternatively or additionally, the insulation material can also be arranged at a different location between the external contacting 18, 17 and an electrode end 11, 12. By way of example, the insulation material can be introduced into the cavities 7, 8 in such a way that it covers the inner side of an external contacting 18, 17. An avalanche breakdown can be prevented in this way, too.

(26) FIG. 2 shows in schematic illustration a method for introducing insulation material into the cavities of the body 1 from FIG. 1.

(27) In this case, a liquid insulation material 13 in a container 14 is provided. The insulation material 13 preferably exhibits a good wetting on the dielectric material. In particular, the wetting angle of contact is embodied as shallow. In this case, the cavities can readily be filled by means of capillary forces. The insulation material 13 can additionally also be used for the external passivation of the body 1.

(28) In one embodiment, the insulation material 13 comprises a lacquer. In particular, an organic insulation material 13 can be involved. By way of example a silicone lacquer comprising xylene and ethyl benzene as diluents is suitable.

(29) In a further embodiment, the insulation material 13 comprises glass. In the course of being introduced into the cavities 7, 8, the glass is present above the melting point. By way of example, the glass comprises a lead or silicon basis.

(30) The body 1 is partly introduced into the insulation material 13. In particular, it is introduced into the insulation material 13 by a third side surface 15. The cavities 7, 8 are exposed on the third side surface 15. Consequently, the insulation material 13 can simultaneously penetrate into the first and second cavities 7, 8. The insulation material 13 rises upward in the cavities 7, 8 by means of capillary forces. In this case, air can escape from the cavities 7, 8 upward. Preferably, the insulation material 13 rises up to an opposite fourth side surface 16. Consequently, the cavities 7, 8 are filled by the insulation material 13 over their entire length.

(31) In this case, the insulation material 13 can completely fill the cavities 7, 8. Alternatively, the cavities 7, 8 can also be only partly filled with insulation material 13. In this case, for example, at least the electrode ends 11, 12 are covered by the insulation material 13 over their entire length. The breakdown voltage can be increased by such sealing of the electrode ends 11, 12, in particular of the cathode tips. Alternatively or additionally, the insulation material 13 can be present at a different location between the electrode ends 11, 12 and the location of the external electrodes 17, 18.

(32) The insulation material 13 can also fill the cavities 7, 8 only over part of the length of the electrode ends 11, 12. In this case, the insulation material 13 is preferably present at least in a region between the electrode ends 11, 12 and the location of the external electrodes 17, 18.

(33) The method carried out comprises a single stage, such that the body 1 is introduced into the insulation material 13 only once. Alternatively, the body 1 can also be introduced into the insulation material 13 a number of times. By way of example, after the introduction of the third side surface 15, said body is subsequently introduced into the insulation material 13 by its fourth side surface 16. This can be advantageous if the insulation material 13 does not rise completely upward in the course of the first introduction of the body 1 into the insulation material 13.

(34) Filling the cavities 7, 8 using the capillary effect is advantageous particularly in the case of cavities having a small width, since the insulation material 13 can be introduced into the narrow cavity in a controlled manner by means of the capillary effect.

(35) Before the body 1 is introduced into the insulation material 13, parts of the body 1 which are not intended to be covered with insulation material 13 can be covered or clamped.

(36) After the introduction of the insulation material 13, the insulation material 13 is cured. In the case of a glass-based insulation material 13, the insulation material 13 can be fired.

(37) During the process of introducing the insulation material 13, the body 1 can already be provided with external contact-connections 17, 18 or can be free of external contact-connections. Possible variants of the method sequence are shown in FIGS. 3 to 8.

(38) FIGS. 3 to 5 show lateral plan views of the body from FIG. 1 in accordance with a first method sequence.

(39) In this case, FIG. 3 shows the body 1 before the introduction of insulation material. No external contacting are applied on the side surfaces 5, 6, and so the cavities 7, 8 are exposed on both side surfaces 5, 6. The body 1 without external contactings is introduced for example into the liquid insulation material 13 as shown in FIG. 2.

(40) Alternatively, the insulation material 13 can be applied to the side surface 5, 6, for example by screen printing. This method is particularly well suited to glass as insulation material 13. The insulation material 13 can be applied as paste to the side surfaces 5,6 and be liquefied by means of a firing process. The insulation material 13 is drawn into the cavities 7, 8 by the capillary forces. By way of example, the insulation material 13 fills only the region of the cavities 7, 8 near the side surfaces 5, 6 and does not advance as far as the electrode ends 11, 12.

(41) FIG. 4 shows the body 1 from FIG. 3 after the introduction of the insulation material 13. The insulation zones 9, 10 here are completely filled with the insulation material 13. The insulation material 13 is cured or fired after or during introduction into the cavities 7, 8. The side surfaces 5, 6, 15, 16 can subsequently be polished in order to remove excess insulation material 13. By way of example, a polishing of the first side surface 5 removes insulation material 13 from the first electrode layers 3.

(42) Afterward, external contactings are applied to the first and second side surfaces 5, 6.

(43) FIG. 5 shows the body 1 after the application of external contactings 17, 18. The external contactings 17, 18 are applied for example as metal pastes to the side surfaces 5, 6 and are subsequently fired. In an alternative embodiment, the external contactings 17, 18 are applied in a sputtering method. In a further alternative embodiment, the external contactings 17, 18 can be embodied as conductive adhesive.

(44) By way of example, a finished component 19 is now present. In an alternative embodiment, the body 1 is separated into a plurality of main bodies for components. This step can be carried out before or after the curing of the lacquer, before or after the polishing of the side surfaces 5, 6, 15, 16 or before or after the fitting of the external contact-connections 17, 18.

(45) FIGS. 6 to 8 show lateral plan views of the body 1 from FIG. 1 in accordance with a second method sequence.

(46) In accordance with this method sequence, external contactings 17, 18 are applied to the body 1 before the insulation material 13 is introduced. This makes it possible, in particular, to use an organic insulation material 13 in conjunction with fired external contactings 17, 18.

(47) FIG. 6 shows the body 1 before the introduction of insulation material and before the application of external contactings.

(48) FIG. 7 shows the body 1 after the application of external contactings 17, 18 to the opposite side surfaces 5, 6. By way of example, the external contactings 17, 18 are produced by metallization pastes which are applied to the side surfaces 17, 18 and fired.

(49) The cavities 7, 8 are still free of insulation material, such that hollow spaces are situated below the external contactings 17, 18.

(50) Insulation material 13 is subsequently introduced into the cavities 7, 8, as illustrated in FIG. 2. Since here the external contactings 17, 18 are already connected to the electrode layers 3, 4, it is possible to omit the step of polishing the surface after the introduction of the insulation material 13.

(51) FIG. 8 shows the body 1 after the introduction of the insulation material 13. The insulation material 13 is cured. By way of example, a finished component 19 is now present. Alternatively, the body 1 can be separated into a plurality of main bodies for components. This step can alternatively be carried out before or after the application of the external contactings 17, 18 or before or after the introduction of the insulation material 13. The component 19 can comprise, in particular, an organic insulation material 13 and fired external contactings 17, 18.

LIST OF REFERENCE SIGNS

(52) 1 Body 2 Dielectric layer 3 First electrode layer 4 Second electrode layer 5 First side surface 6 Second side surface 7 First cavity 8 Second cavity 9 First insulation zone 10 Second insulation zone 11 First electrode end 12 Second electrode end 13 Insulation material 14 Container 15 Third side surface 16 Fourth side surface 17 First external contacting 18 Second external contacting 19 Component S Stacking direction