Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/01—Manufacture or treatment
  • H10N30/05—Manufacture of multilayered piezoelectric or electrostrictive devices, or parts thereof, e.g. by stacking piezoelectric bodies and electrodes
  • H10N30/053—Manufacture of multilayered piezoelectric or electrostrictive devices, or parts thereof, e.g. by stacking piezoelectric bodies and electrodes by integrally sintering piezoelectric or electrostrictive bodies and electrodes
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/01—Manufacture or treatment
  • H10N30/06—Forming electrodes or interconnections, e.g. leads or terminals
  • H10N30/063—Forming interconnections, e.g. connection electrodes of multilayered piezoelectric or electrostrictive parts
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/42—Piezoelectric device making
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
  • Y10T29/49126—Assembling bases
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
  • Y10T29/49128—Assembling formed circuit to base
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
  • Y10T29/49155—Manufacturing circuit on or in base
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
  • Y10T29/49155—Manufacturing circuit on or in base
  • Y10T29/49163—Manufacturing circuit on or in base with sintering of base

Definitions

• the present invention relates to a piezoceramic multilayer actuator and various methods for its production.
• piezoelectric ceramics of suitable crystal structure can expand or contract when generating an electric field in their interior. This long change takes place with almost no delay relative to the controlling electrical signal and is also precisely controllable. Therefore, piezoelectric multilayer actuators are used as adjusting elements.
• the piezoceramic multilayer actuators are produced with layer thicknesses in the range of 100 ⁇ m. Typical manufacturing processes are slip casting or dry pressing.
• the individual ceramic layers are metallized and stacked on top of each other so that internal electrodes of opposite polarity can produce the piezoelectric effect between two ceramic layers. Via an outer metallization parallel to the stacking direction or longitudinal axis of the piezoceramic multilayer actuator, mutually all internal electrodes of the same electrical potential are electrically driven.
• the internal electrodes of the respectively opposite electrical potential are arranged offset in relation to the other electrodes in the area of the external metallization of the internal electrodes of the respective opposite potential.
• This layer structure within the piezoceramic multilayer actuator results in design-induced piezoelectrically inactive zones. Since the piezoceramic multi-layer If the inner diameter of the electrodes of different polarity is arranged directly above one another in the piezoelectric active regions, mechanical stress within the multilayer actuator occurs in the transition region to piezoelectrically inactive zones. These mechanical stresses led to crack formation in the layer structure of the multilayer actuator, which can impair the electrical contact of the outer metallization to the individual electrodes or even lead to total failure of the multilayer actuator.
• EP 1 206 804 Bl discloses a production method for piezoelectric multilayer actuators. Electrochemically electrically conductive materials are deposited on the side surfaces of the electrodes of the same polarity on the individual multilayer structures. These materials form webs, which are electrically connected to each other after isolating the side surfaces of the electrodes arranged between these webs.
• DE 42 24 284 A1 discloses the production of a multilayer bar and its subsequent sintering as a precursor for the production of piezoceramic multilayer actuators.
• a bar has, for example, the depth perpendicular and the length parallel to its stacking direction according to a later multilayer actuator. Its width perpendicular to the stacking direction is a multiple of a later width of a piezoceramic multilayer actuator.
• the electrode structure of the individual piezoceramic multilayer actuators is generated jointly on the multilayer bar and subsequently this is broken down into individual multilayer actuators. sets.
• electrochemically conductive material is deposited on the side surfaces of every second electrode.
• the intervening areas, ie ceramic and electrode, are reset by etching or mechanical removal into the sintered multi-layer bar. This process is expensive because the sintered multi-layer bar is resistant to mechanical and chemical attack. Subsequently, an insulation layer is applied in the recessed regions and external electrodes are generated for each spatter multi-layer actuator. Finally, the sintered multilayer bar is divided into individual piezoceramic multilayer actuators.
• US 5,568,679 and WO 2005/075113 Al also describe the production of structured external electrodes on an already sintered multilayer precursor.
• an electrically insulating material is electrochemically deposited, so that the side surfaces of these electrodes are insulated to the outside.
• an electrically conductive material is applied to the outer sides, which connects the still exposed side surfaces of the electrodes of the other polarity.
• the sintered multilayer bar with structured electrode is divided into individual piezoceramic multilayer actuators.
• Manufacturing method comprising the following steps: producing a multi-layer bar as Grunkorper consisting of an alternating arrangement of a plurality of piezoceramic layers and a plurality of electrodes in a stacking direction of the multilayer bar, while a depth of the
• Multilayer bar perpendicular to the stacking direction of a depth of a multilayer actuator and a width of the multilayer bar perpendicular to the stacking direction of a width of a plurality of multilayer actuators corresponds and the electrodes over the entire depth of the multilayer bar and alternately on opposite end faces of the multilayer bar starting from not extending the entire width of the multilayer bar, arranging opposing auxiliary electrodes at the front sides spaced by the width of the multilayer bar, so that each second electrode is electrically controllable with the opposing auxiliary electrodes around one electrode in the stacking direction, electrochemical reset parallel to the depth of the multi-layer bar, in particular etching, of a side surface of each second electrode so that on opposite broad sides of the multilayer bar each second side surface of the electrode in the multilayer bar Latch is reset and the recessed surfaces of the electrodes on opposite broad sides of the multi-layer bar in the stacking direction around a piezoceramic layer are spaced from each other, coating the recessed surfaces of the electrodes with an
• the majority of the production steps are carried out on a multi-layer bar in the green state.
• This bar is due to its not yet sintered ceramic Gefuges with less effort and therefore workable at lower cost.
• the multi-layer bar with auxiliary electrodes offers the possibility of simultaneously producing a plurality of piezoelectric multilayer actuators at its end faces which are spaced apart by the width, by separating the multilayer bar into individual multilayer actuators at the end of the production process.
• each second electrode In order to produce structured electrodes on the outer sides of the multi-layer bar, the side surfaces of each second electrode are first reset or set into the multi-layer bar by etching.
• the forming depressions, in which the side surfaces of each second electrode are arranged, are filled with slip of an electrically insulating material after burnout. These materials are, for example, glass or ceramic.
• the side surfaces of each second electrode to be electrically connected are exposed outside the wells, so that they can be electrically connected to each other, for example, by printing an external metallization.
• these depressions are filled with a slip of electrically-insulating material after burning out. Therefore, only the increased by electrochemical deposition side surfaces of the electrodes of the multilayer bar at its broad sides are free.
• the advantages of facilitated processing of a multi-layer bar in the green state and the simultaneous production of a plurality of multilayer actuators with the aid of this multi-layer bar are utilized.
• it has an advantageous effect that the side surfaces, arranged in depressions, of the electrodes to be electrically insulated by slips can be effectively isolated.
• the burnout of the slurry takes place, for example, in combination with the sintering of the multilayer bar in order to achieve a further optimization of the production process.
• a multi-layer bar as a green body consisting of an alternating arrangement of a plurality of piezoceramic
• FIG. 1A, B show various embodiments of a multi-layer bar
• FIG. 2 shows a schematic representation of the electrochemical treatment of a multilayer bar
• FIG. 3 shows an enlarged detail of the multilayer bar after the step of the electrochemical deposition
• FIG. 4 shows a section of the multi-layer bar after the process of etching
• FIG. 5 shows an enlarged detail of the multi-layer bar to illustrate the removal by means of legend, grinding and similar methods
• FIG. 6 shows a representation of the section along the line AA of FIG. 5
• 7 shows an enlarged detail of the multi-layer bar to illustrate the removal not parallel to the side surface of the electrodes
• Figure 8 is a sectional view taken along the line A-A
• Figure 9 is a sectional view taken along the line B-B
• Figure 10 is a sectional view taken along the line C-C
• FIG. 11 shows a flow chart for a schematic representation of different process sequences of the production method.
• first piezoceramic green films are cast.
• the green sheets are printed with electrode material, which consists for example of silver-palladium alloys. These surfaces form the later internal electrodes 20.
• the printed green films are arranged in the stacking direction S one above the other to form a stack.
• An unprinted green film is preferably arranged between two printed green films in order to reduce the risk of electrical short circuits in the interior of the later multilayer actuator.
• the width and depth of the block are each a multiple of the depth and width of a later multilayer actuator.
• the block is sufficiently stable to be processed chemically, mechanically or otherwise.
• the joint of the block is less resistant than in the sintered state, so that a processing of the block with less effort Deutschenchtbar.
• the block (not shown) in the green state is divided into a plurality of multilayer bars 10, for example by saying.
• the multi-layer bar 10 as a green body comprises an alternating arrangement of a plurality of piezoceramic layers 30 and a plurality of electrodes 20 in the stacking direction S.
• a depth T of the multi-layer bar 10 perpendicular to its stacking direction S corresponds to a depth of a multi-layer actuator after manufacture and a width B of the multi-layer bar 10 perpendicular to its stacking direction S corresponds to a width of a plurality of multilayer actuators after their production (see Fig. IA, B).
• the electrodes 20 of the multilayer bar 10 extend over the entire depth T of the multilayer bar 10.
• the multilayer bar 10 corresponds to the height H of the multilayer bar 10 approximately to a height of a later multilayer actuator in the sintered state.
• the multilayer bar 10 is divided into individual multilayer actuators by separating cuts parallel to its stacking direction S (compare the dashed lines in FIG.
• the sintered multi-layer bar 10 is divided by cuts parallel and perpendicular to its stacking direction S along the dashed lines.
• the multi-layer bar 10 in the green state comprises the already mentioned above, each alternately arranged in the stacking direction S piezoceramic layers 30 and electrodes 20.
• the side surfaces 22, 24 of the electrodes 20 each extend to the surface of the broad sides 12 of the multi-layer bar 10.
• Der Multi-layer bar 10 comprises at its opposite end faces 15 each have an auxiliary electrode 25.
• Each second electrode 20 starts at an auxiliary electrode 25 and ends in front of the opposite auxiliary electrode 25.
• the electrodes 20 therefore do not extend over the entire width B of the multi-layer latch 10.
• Each second electrode 20 with the side surfaces 22 or 24 is thus electrically controllable based on the use of the auxiliary electrodes 25 together.
• this construction also results in the piezoelectrically inactive regions 5 adjacent to the end faces 15 of the multi-layer bar 10. These are to be regarded as lost areas for the production of multilayer actuators since they have no further use after completion of the production process.
• the multilayer bar 10 After the multilayer bar 10 is in the green state, i. the steps of producing the multilayer bar Sl and arranging auxiliary electrodes S2 are completed, it is preferable to insulate a broad side 12 with a passivation layer. After the application of the passivation layer, the multilayer bar 10 is treated electrochemically in an electrolyte bath (compare FIG. 2). It is also conceivable to process the multilayer bar without passivation layer. In this case, only one broad side 12 of the multi-layer bar is immersed in an electrolyte 52 (see Fig. 2) to process this broadside electrochemically.
• the multilayer bar 10 is electrochemically processed by electrically conductive material on the side surfaces 22; 24 of the electrodes 20 is deposited.
• the plating bath contains the electrolyte 52 and a plating electrode 54 for applying a direct electrical voltage via the voltage source 50 between the plating electrode 54 and one of the auxiliary electrodes 25
• DC voltage source 50 is connected to only one of the auxiliary electrodes 25, so that coated on a broad side 12, only the side surfaces 22 with electrically conductive material become.
• the metal ions from the electrolyte 52 migrate in the electric field in the direction of the electrodes 20 and deposit there on the side surfaces 22.
• the passivation layer is removed and applied to the opposite broad side 12 or the opposite broad side 12 is immersed in the electroplatable. The fact that now the other auxiliary electrode 25 is connected to the DC voltage source 50, only the side surfaces 24 of the electrodes 20 are coated with electrically conductive material on the opposite broad side 12.
• the coated side surfaces 22, 24 on the opposite broad sides 12 are therefore spaced from each other by a piezoceramic see layer 30, as shown in Fig. 3.
• the electrochemically deposited electrically conductive material on the side surfaces 22 or 24 of the electrodes 20 thus includes depressions 40, in each of which an electrode 20 is arranged.
• a similar well structure as in FIG. 3 is produced by electrolytic etching S4.
• the multi-layer bar 10 is immersed in an etching bath only with one broad side 12 or completely with a previously passivated broadside 12.
• the etch bath preferably comprises customary electrolyte solutions, such as, for example, aqueous sodium chloride solution or sodium nitrate solution.
• an electrical direct voltage is applied to the electrode 20 with the side plates 22 via only one auxiliary electrode 25. Therefore, only the side surfaces 22 of the electrodes 20 are electrochemically removed.
• the opposite broad side 12 is immersed in the etching bath and the other auxiliary electrode 25 is electrically driven. As a result, the side surfaces 24 of the electrodes 20 are removed.
• the opposite broad side 12 with a passivation layer and to drive the other auxiliary electrode 25 electrically.
• the side surfaces 24 are etched or returned. puts. It forms again on both broad sides 12 a plurality of depressions 40 between each non-patted side surfaces 22 or 24 of the electrodes 20. Since the side surfaces 22, 24 are smaller in comparison to the piezoceramic side surfaces of the layers 30, they can be etched with less effort and thereby reset parallel to the depth direction T in the multilayer bar 10.
• the depressions 40 are filled with a slip.
• the slip fills the depressions 40 (see Figures 3 and 4) to such an extent that the respective electrodes 20 arranged in the depressions 40 are covered by a layer (not shown).
• the slurry is preferably based on a ceramic or glassy powder, so that after drying the slurry an electrically insulating layer is formed in the depressions 40 above the electrodes 20.
• the slurry in the wells 40 is also solidified, so that a resistant layer is formed without a separate heat treatment.
• the multilayer bar 10 electrochemically after the sintering, ie to deposit conductive materials or side surfaces 22; 24 of the electrodes 20 penetratezuatzen to produce the sink structure described above. Subsequently, the wells 40 are filled with slurry and this cured with a tuned to him thermal treatment. Then the application of the outer metallizations and the separation of the multilayer bar into individual multilayer actuators takes place.
• outer metallizations are printed on in the areas that result in 10 individual multilayer actuators after the multi-layer bar has been cut (S7).
• the printing of the outer metallizations takes place with, for example Screen printing or other common procedures.
• the multi-layer bar 10 is sintered with external metallization and separated into individual multilayer actuators along the dashed lines in Figures IA, B. In the course of the separation, the inactive areas 5 with the adjacent ones become
• the sink structure described above is obtained by removing S5 of the side surfaces 22; 24 of the electrodes 20 shown in FIG. 5 to 10 generated.
• the production route with this method step S5 requires neither a multi-layer bar 10 / stack (see below) with auxiliary electrodes 25 and piezoelectrically inactive areas 5 nor a passivation layer. Therefore, a simplified processing compared to the previous process routes on a piezoelectric fully active layer structure is possible here.
• the electrode surfaces 22 are removed on a broad side 12.
• the ablation takes place by means of grinding, welding, lasering, eroding and / or pushing in the depth direction T of the multi-layer bar 10.
• the lateral surfaces 22 of each second electrode 20 are removed parallel to their direction of progression on a broad side 12 (see Fig. 5, 6).
• FIG. 6 shows a section along the line AA from FIG. 5. The above process is performed on both broad sides 12 of the multi-layer bar 10 to subsequently insulate the wells with slurry, apply exterior metallizations, and perform sintering S8 (see above).
• the removal direction 60 is not parallel to the running direction of the side surfaces 22; 24 of the electrodes 20 aligned (see Fig. 7).
• the lowering structure is again obtained by the non-parallel removal (see Fig. 8), as already described above.
• the depressions 40 are in this case spatially on a portion of the side surfaces 22; 24, as can be seen from the sections along line B-B and C-C in Fig. 7 (see Figures 9 and 10).
• the multilayer bar 10 it is also conceivable to first sinter the multilayer bar 10 and only then to remove it (see above) to produce the sink structure. Subsequently, the side surface 22; 24, the electrodes 20 disposed in the depressions 40 are electrically insulated and the slurry is solidified by thermal treatment. According to a further alternative, the removal is not performed on a multilayer bar, but already on a stack (not shown) of the later multilayer actuator. If the stack is in the green state, the thermal treatment of the slip in the sink structure created by the removal is linked to the sintering of the stack. If the stack is in the sintered state, a thermal treatment for curing the slurry is carried out after the removal and application of the slurry in the sink structure.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
• Fuel-Injection Apparatus (AREA)

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• 2007
  • 2007-01-31 DE DE102007004813.2A patent/DE102007004813B4/de active Active
• 2008
  • 2008-01-15 WO PCT/EP2008/050403 patent/WO2008092740A2/de not_active Ceased
  • 2008-01-15 CN CN200880003824.7A patent/CN101601147B/zh not_active Expired - Fee Related
  • 2008-01-15 EP EP08707901A patent/EP2126995B1/de active Active
  • 2008-01-15 JP JP2009547627A patent/JP5167280B2/ja active Active
  • 2008-01-15 US US12/524,549 patent/US7905000B2/en not_active Expired - Fee Related
  • 2008-01-15 AT AT08707901T patent/ATE540434T1/de active

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