Abstract:
A micromechanical component having a base part, a swiveling part, which has an electrically conductive material, and a swiveling part insulation which electrically insulates a first and a second section of the swiveling part from each other. A first flexible, electrically conductive connecting element connects the base part to the first swiveling part section, and a second flexible, electrically conductive connecting element connects the base part to the second swiveling part section. A method also created for producing a micromechanical component includes the following steps: providing a substrate wafer that has a conductive overlayer, etching an insulation trench into the overlayer that insulates a first and second section of the overlayer from each other, as well as forming a base part and a swiveling part including the first and the second section of the overlayer from the substrate wafer, while allowing to remain a first flexible, electrically conductive connecting element, which connects the base part to the first swiveling part section, and allowing to remain a second flexible connecting element which connects the base part to the second swiveling part section.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a micromechanical component and a production method for a micromechanical component. 
     2. Description of Related Art 
     Micromechanical components are usually adjusted via electrostatic or electromagnetic drives. It is known, for example, that one may swivel micromirrors electrostatically, using comb actuators or plate actuators, which each include so-called comb electrodes or plate electrodes, from an initial position into an end position. Such micromirrors are used for the optical deflection of light beams, for instance, in projectors or scanners. Comb actuators are also used to activate acceleration sensors. One additional exemplary application for plate actuators is micropumps. In the case of an electromagnetic drive, it is customary to mount coils on the movable elements, such as on a micromirror, and permanent magnets outside the movable elements. 
     One variant of the micromirrors is suspended in such a way that it is able to be swiveled about two rotational axes that are perpendicular to each other. The suspension is usually made to be double Cardanic, the micromirror being suspended in a frame, using a pair of torsional springs, and the frame is suspended, using an additional pair of torsional springs, on immobile elements. Electric lines to the frame are required for the drive of the mirror and the monitoring of its position with respect to the frame using, for instance, additional electrodes acting as a sensor. 
     However, metallic printed circuit traces on the torsional springs, on which the frame is suspended, must be designed to be very narrow, since the available surface of the torsional springs is small. This calls for a high electrical resistance of the lines. Since metal printed circuit traces typically have ductile properties, they damp the deflection of the frame, and lower the quality of the vibrator formed of the frame and the torsional springs carrying it. As a result, for the resonant drive of the mirror, higher deflection forces are required having correspondingly higher drive voltages and/or drive currents, to compensate for the damping. Drive voltage and drive current are limited, however, among other things, by the limited surface of the torsional springs. In addition, the printed circuit traces are subject to great disruptions, based on of the deformation of the torsional springs. 
     SUMMARY OF THE INVENTION 
     The present invention creates a micromechanical component and a method for producing a micromechanical component. 
     In a micromechanical component having a base part and a swiveling part, which are connected to each other movably by at least two flexible connecting elements, such as torsional springs or elastic bending beams, the present invention is based on the idea of developing the flexible connecting elements themselves to be conductive, so that they may act as supply lines without metallic printed circuit traces having to be developed on the connecting elements. In this context, the swiveling part has a conductive material, and an insulation which insulates the two sections of the swiveling part electrically, with respect to each other. Of the two connecting elements, the first one is connected to the swiveling part at its first section, whereas the second one is connected to the swiveling part at its second section. 
     Since the swiveling part itself has a conductive material, there is in each case an electrical connection between the first and second connecting element and the respective first and second swiveling part section at which it is connected to the swiveling part. This makes it possible for the swiveling part to contact the conductive material of the swiveling part in the corresponding first or second swiveling part section, for instance, by printed circuit traces, and thus to produce an electrical connection to the base part, which runs over the first and second connecting element. The connecting elements themselves remain free of printed circuit traces and contacts, in this instance. 
     The electrical insulation of the first and second swiveling part section with respect to each other prevents the two connecting elements from being short-circuited electrically via the conductive material of the swiveling element. This makes it possible to guide two supply lines via the two connecting elements which are electrically independent of one another. It is possible, for example, to guide a drive electrode for driving the swiveling part and a sensor electrode for determining a current swiveling position of the swiveling part via respectively one of the connecting elements. By the provision of additional connecting elements, the number of possible electrically independent supply lines increases correspondingly. 
     Since the electrical connections are made available on the connecting elements without damping printed circuit traces, particularly large deflection angles of the swiveling part are achievable at a given control voltage, particularly if the swiveling part is excited to a resonant vibration. Therefore, in reverse, the control voltage may also be lowered in order to achieve a sufficient deflection so that the power consumption and the development of heat in the component fall off. Alternatively, the spring stiffness of the connecting elements may also be increased, in order to achieve the same deflection angles with greater torque at an unchanged control voltage. This has the effect of particularly low sensitivity with respect to outer interferences, advantageously short retrace time of the swiveling part, as well as great resistance to mechanical shock and electrostatic collapse. 
     According to one preferred refinement, the first and/or the second connecting element has the same electrically conductive material as the swiveling part. This has the advantage that the first and/or second connecting element and the swiveling part are able to be formed in one production step of the same material block. Furthermore, especially in the case of a one-piece production, there is a lower contact resistance between the first and the second connecting element on the one hand, and the swiveling part section, to which the latter is connected, on the other hand. 
     According to one preferred refinement, the swiveling part insulation, which, on the swiveling part, insulates the first and second swiveling part section from each other, includes an insulation trench between the first and second swiveling part section. In this way, the swiveling part sections may be developed on a wafer surface in a geometrically desired form, by using a trench etching method that is easy to carry out. 
     According to another preferred refinement, the swiveling part has a conductive substrate. The swiveling part insulation includes an insulating layer which insulates the first and second swiveling part section from the conductive substrate. This has the advantage that electrode blocks and other electrically conductive elements, for example, are able to be formed of the conductive substrate, without their geometrical situation along the substrate side of the insulation layer restricting the geometrical positioning possibilities of the first and second swiveling part section on the side of the insulating layer that is opposite to the substrate. 
     In one preferred further development, a printed circuit trace is developed on the swiveling part, which connects the first swiveling part section to the conductive substrate via an opening in the insulating layer. This has the advantage that the substrate region lying below the opening, such as, for instance, an electrode formed in this region from the substrate, is connected electrically to the base part via the printed circuit trace, the first swiveling part section and the first connecting element, so that it may be acted upon with a control voltage, for instance, from the side of the base part. In particular, it is also made possible to contact a substrate region that does not lie below the first swiveling part section when the printed circuit trace is guided via the insulation trench. 
     In the case of another preferred refinement, the base part has a base part insulation which electrically insulates a first and second conductive base part section from each other. The first connecting element connects the first swiveling part section to the first base part section, and the second connecting element connects the second swiveling part section to the second base part section. With that, there exists in each case an electrical connection between the first and second connecting element and the respective first and second base part section, at which it is connected to the base part. This makes it possible for the base part to contact the corresponding conductive base part section, for instance, by printed circuit traces, and thus to produce an electrical connection to the swiveling part, which runs via the first and second connecting element. The connecting elements themselves remain free of contacts and printed circuit traces on both sides. 
     The method of the present invention for producing a micromechanical component includes the following steps: providing a substrate wafer that has a conductive overlayer, etching an insulation trench into the overlayer that insulates a first and second section of the overlayer from each other, as well as forming a base part and a swiveling part including the first and second section of the overlayer from the substrate wafer, while allowing to remain a first flexible, electrically conductive connecting element, which connects the base part to the first swiveling part section, and allowing to remain a second flexible connecting element which connects the base part to the second swiveling part section. 
     According to still another refinement of the method according to the present invention, the first and/or the second connecting element are formed from the conductive overlayer. In this way, the swiveling part is able to be swiveled about a swiveling axis that runs in the overlayer parallel to the wafer plane, so that a large torque is able to be generated about the swiveling axis, for instance, using the electrodes formed from the substrate. 
     According to one preferred refinement, the etching of the insulating trench takes place isotropically. This has the advantage that sidewalls of the insulating trench are given a slantwise course, so that printed circuit traces, which cross the insulating trench, are able to be applied to the overlayer. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       In the following, the present invention is explained in greater detail with the aid of the exemplary embodiments shown in the schematic figures of the drawings. 
         FIG. 1  shows a summary type of top view onto a micromechanical component according to a specific embodiment of the present invention. 
         FIG. 2A  shows an enlarged view of a detail cutout, marked in  FIG. 1 , of the micromechanical component of  FIG. 1 . 
         FIG. 2B  shows an enlarged view of a detail cutout marked in  FIG. 1 , for an additional, modified specific embodiment of a micromechanical component. 
         FIG. 3A  shows a cutout-type of cross sectional view of the micromechanical component of  FIGS. 1 and 2A . 
         FIG. 3B  shows a cutout-type of cross sectional view of the micromechanical component of  FIGS. 1 and 2A , in a deflected state. 
         FIG. 4  shows a summary type of top view onto a micromechanical component according to an additional specific embodiment of the present invention. 
         FIG. 5  shows a summary type of top view onto a micromechanical component according to still another specific embodiment of the present invention. 
         FIG. 6  shows a flow chart of a production method for a micromechanical component according to one specific embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Unless specifically mentioned otherwise, identical or functionally equivalent elements have been provided with the same reference numerals in all the figures of the drawings. 
     In  FIG. 1 , a summary type of top view shows a micromirror device  100 , which represents a micromechanical component  100  according to one specific embodiment of the present invention.  FIG. 2A  shows an enlarged view of a detailed cutout of the micromirror device of  FIG. 1  marked in  FIG. 1  by A/B. Micromirror device  100  is produced from a multi-layer wafer, which has a conductive substrate, such as, for instance, a suitably doped silicon or another semiconductor material, a conductive, thinner overlayer  300  made of the same material or a different material, and an insulating intermediate layer, made of silicon oxide, for example, between the substrate and overlayer  300 . The top view of  FIGS. 1 and 2A  corresponds to a view from above onto overlayer  300 , perpendicular to the wafer plane. 
     Micromirror device  100  includes a base part  102 , which surrounds in a frame-like manner a swiveling part  104  that is separated from it by a continuous gap  130 . Swiveling part  104  is suspended on base part  102  in a springy manner by torsional springs  112 ,  114 , which, for the sake of clarity, are shown only in the detailed view of  FIG. 2A , and is able to be swiveled, going into the plane of the drawing, with respect to base part  102  about an axis  136  defined by torsional springs  112 ,  114 . All in all, the micromirror device has four torsional springs  112 ,  114  along axis  136 , of which a first torsional spring  112 , and a second torsional spring  114 , are situated in a first suspension region  132 , shown in  FIG. 2A , and two additional torsional springs are situated in a second suspension region  134 . Axis  136  runs in the middle of gap  130  between the base  102  and swiveling part  104  in suspension regions  132 ,  134 , at the height of overlayer  300 . The torsional springs  112 ,  114  are suspended on projections  154 ,  156 , which project from swiveling part  104  and base part  102  respectively, out beyond axis  136  into gap  130 . 
     Between the two suspension regions  132 ,  134 , swiveling part  104  has an inner frame  128  that is rectangular, for example, inside of which a mirror plate  122 , that is circular, for instance, is suspended between two additional torsional springs  124 ,  126 . Additional torsional springs  124 ,  126  are situated along an additional axis  138 , that run at right angles to axis  136 , so that overall, a double Cardanic suspension  112 ,  114 ,  128 ,  124 ,  126  results of mirror plate  122  on base part  102 . 
     In the two suspension regions  132 ,  134 , along a plane which runs perpendicular to the plane of the drawing, through axis  136 , an electrode block  144  of swiveling part  104  and an electrode block  146  of base part  102  are facing each other. The two electrode blocks  144 ,  146  are formed of the substrate of the wafer, and each includes a set of parallel plate electrodes  140 ,  142 , of which each is positioned in a plane running perpendicular to axis  136 . Because electrode blocks  144 ,  146  are covered by overlayer  300  lying on top of them, in the top view shown, the outlines of plate electrodes  140 ,  142  are reproduced in dashed lines. One plate electrode  140  of swiveling part  104  in each case faces a gap  148  between two plate electrodes  142  of base part  102 , which is wider than plate electrode  142 , so that, during operation of the micromirror device, during the swiveling of swiveling part  104  about axis  136  into the plane of the drawing, the two electrode blocks  144 ,  146  are displaced into each other without touching. 
     On the side of electrode blocks  144 ,  146  facing away from axis  136 , there is in each case a massive substrate block  150  or  152  adjacent to corresponding electrode blocks  144 ,  146 , which supports plate electrodes  140 ,  142 . Plate electrodes  140  and  142  of each of the two blocks  144 ,  146  are electrically connected to each other via supporting substrate blocks  150 ,  152 . Above electrode blocks  140 ,  142  and massive substrate blocks  150 ,  152  there runs the insulating intermediate layer, and on it, there runs conductive overlayer  300 , so that in the top view shown, the view onto plate electrodes  140 ,  142  is concealed by overlayer  300  and the intermediate layer. 
     On the part of swiveling part  104 , insulation trenches  106  are etched into overlayer  300 , which extend to the insulating intermediate layer, and which laterally divide overlayer  300  of swiveling part  104 , within the first suspension region shown in  FIG. 2A , into a first  108 , second  110  and third  111  swiveling part section, so that the conductive material of overlayer  300  in the three sections  108 ,  110 ,  111  are insulated from one another by the intermediate layer not lying in insulating trenches  106  and lying under overlayer  300 , with respect to the conductive material of overlayer  300  in the respectively other ones of sections  108 ,  110 ,  111 . 
     On the part of base part  102 , in the same way, corresponding insulation trenches  116  are etched into overlayer  300 , which extend to the insulating intermediate layer, and which laterally divide overlayer  300  of swiveling part  102 , within the first suspension region shown in  FIG. 2A , into a first  118 , second  120  and third  121  base part section, so that the conductive material of overlayer  300  in the three sections  108 ,  110 ,  121  are insulated from one another by the intermediate layer not lying in insulating trenches  116  and lying under overlayer  300 , with respect to the conductive material of overlayer  300  in the respectively other ones of sections  108 ,  120 ,  121 . 
     First swiveling part section  108  includes projection  154 , via which first torsional spring  112  is fastened to swiveling part  104 . First base part section  118  includes a part of projection  156  that is separated by insulating trench  116 , via which first torsional springs  114  is fastened to base part  102 . First torsional springs  112  has the same conductive material as overlayer  300  in first swiveling part section  108  and first base part section  118 . That is why first base part section  118 , first torsional spring  112  and first swiveling part section  108  form an electrically conductive supply line  118 ,  112 ,  108  from base part  102  onto swiveling part  104 . An additional electrically conductive supply line from base part  102  onto swiveling part  104  is formed, in an analogous manner, by second base part section  120 , second torsional springs  114  and second swiveling part section  110 . By also providing corresponding insulating trenches, not shown in  FIG. 1 , in second suspension region  134 , via the four torsional springs along axis  136 , altogether four electrical supply lines, that are independent of one another, and are insulated from one another by insulation trenches  106 ,  116 , are able to be provided from base part  102  onto swiveling part  104 . 
       FIG. 3A  shows a cutout-like cross sectional view of micromirror device of  FIGS. 1 and 2A , whose sectional surface is marked as A-A′ in  FIG. 2A , and runs perpendicular to the plane of the drawing in  FIGS. 1 and 2A . The cross sectional view clarifies the structure of the device, that is made of a multi-layer wafer which includes a thick substrate  304 , an insulating layer  302  and an overlayer  300 . Plate electrodes  140 ,  142  and massive blocks  150 ,  152  supporting them are formed from substrate  304 . Overlayer  300  is totally insulated by insulating layer  302  from substrate plane  304 . Insulating trenches  106 ,  116 , that reach down to insulating layer  302 , which insulate sections  108 ,  111  and  118 ,  121  of overlayer  300  laterally from one another, have a cross section that tapers in the downward direction, which may be produced, for instance, by an isotropically acting etching method. 
     Metallic printed circuit traces  160 - 164  are developed on overlayer  300 , which are electrically insulated from overlayer  300  by a suitably underlaid printed circuit trace insulating layer  306 . Printed circuit trace insulating layer  306  also covers the inclined walls of insulating trenches  106 ,  116 . In exemplary fashion,  FIG. 3A  also shows the course of printed circuit trace  164  along line A-A′. Printed circuit trace  164  crosses insulating trench  106 , by running on its inclined, gently curved walls, which are continuously underlaid by printed circuit trace insulating layer  306 . At a substrate contacting location  170 , a funnel-shaped depression  174  is etched into overlayer  300 , which, same as insulating trenches  106 ,  116 , has inclined, gently curved sidewalls, which are covered by printed circuit trace insulating layer  306 . In the center of funnel-shaped depression  174 , insulating intermediate layer  302 , that runs under overlayer  300 , is broken through towards the substrate, for example, by an etching step during production, which locally and selectively removes the material of intermediate layer  302 . At this location  170 , the printed circuit trace contacts substrate  304 , in the vicinity of plate electrode  140 . At an overlayer contact location  172 , in first swiveling part section  108 , printed circuit trace insulating layer  306  is broken through, so that printed circuit trace  164  contacts first swiveling part section  108 . As may be seen in  FIG. 2A , printed circuit trace  164  is continued in the direction of mirror frame  128 . 
     On base part  102 , a correspondingly formed printed circuit trace  162  runs to an overlayer contact location  172  in first base part section  118 . With that, there is provided overall an electrical supply line from the end of printed circuit trace  162  at the edge of the base part, via its overlayer contact location  172 , first base part section  118 , first torsional spring  112 , first swiveling part section  108 , overlayer contact location  172  of printed circuit trace  164 , printed circuit trace  164  and substrate contacting location  170  of printed circuit trace  164  to plate electrode  140 . During operation, this supply line may be used, for example, to control plate electrodes  140  of electrode block  144 . The continuation of printed circuit trace  164  in the direction of mirror frame  128  is furthermore able to provide, for instance, a connection to a similar electrode block  144 ′ of swiveling part  104  in second suspension region  134 , so that plate electrodes  140 ,  140 ′ of the swiveling part are able to be controlled in common on both sides of mirror frame  128  via printed circuit trace  162 . 
     An additional electrical connection from the edge of base part  102  is provided by printed circuit trace  161 , an overlayer contact location  172  in second base part section  120 , second torsional spring  114 , an additional overlayer contact location  172  in second swiveling part section  110  and printed circuit trace  163  running on swiveling part  104 . Via this connection, for example, a sensor electrode, that is not shown, on mirror frame  128  is able to be operated, using which the deflection position of mirror frame  128  is able to be monitored. Printed circuit trace  160 , substrate contacting location  170  that is contacted to it, provide an electrical supply line from the edge of base part  102  to plate electrodes  142  in electrode block  146  of base part  102 . The continuation of printed circuit trace  160  shown, in the direction of second suspension region  134  may furthermore provide, for instance, a connection to a similar electrode block  146 ′ of base part  102  in second suspension region  134 , so that plate electrodes  142 ,  142 ′ of base part  102  are overall able to be controlled via printed circuit trace  160 . 
       FIG. 3B  shows micromirror device  100  of  FIGS. 1 ,  2 A and  3 A in a deflected state, in which swiveling part  104  has been swiveled about axis  136  with respect to base part  102 . During the swiveling, a partial overlapping  308  of plate electrodes  140 ,  142  takes place, the area of overlapping  308  becoming larger with progressive swiveling. Plate electrodes  140 ,  142  of swiveling part  104  and base part  102  that partially overlap in this fashion, form a plate capacitor, whose capacitance increases with increasing swiveling. 
     In the operation of micromirror device  100 , if an electric voltage is applied to printed circuit traces  160  and  162 , electrode blocks  144 ,  146  of swiveling part  104  and base part  102  are at different potentials. Plate electrodes  140 ,  142  of both blocks  144 ,  146  are pulled into each other in comb-like fashion without touching each other. Thus, in principle, a large swiveling angle is achievable as a function of the control voltage. 
       FIG. 2B  shows an enlarged view of the detailed cutout marked in  FIG. 1 , for an additional, modified specific embodiment. By contrast to the specific embodiment of  FIGS. 1 and 2A , the specific embodiment of  FIGS. 1 and 2B  has elastic bending beams  112 ,  114  as connecting elements between base part  102  and swiveling part  104 . Such bending beams may be formed, for instance, from an additionally applied thin layer made of a conductive material, such as epitaxially applied polysilicon. A further difference is that in first swiveling part section  108 , a local contact location  176  is developed in a funnel-shaped depression in overlayer  300 , which directly produces an electrical contact between overlayer  300  in first swiveling part section  108  and massive substrate  150  lying below it. With that, there exists an electric supply line to plate electrodes  140  of swiveling part  104  via printed circuit trace  162 , first base part section  118 , bending beam  112 , first swiveling part section  108 , local contact location  176  and massive substrate block  150 . 
     Furthermore, this specific embodiment shows elongated starter electrodes  180 , which also overlap in a non-deflected state with opposite plate electrodes  142 , in order to avoid a non-steady torque curve in response to activation from the stationary position. Alternatively to such starter electrodes, a steady torque curve may be achieved by operating the device, during operation, only above a minimum deflection angle of 1°, for example. In such an operating mode, in addition, interfering optical reflections of the light deflected by mirror  122  to entrance windows and exit windows situated parallel to the wafer plane may be avoided. 
       FIG. 4  shows a micromechanical component in a summary-type top view, according to an additional specific embodiment. As in the summary-type top view of  FIG. 1 , for the sake of clarity, no insulating trenches  106 ,  116 , printed circuit traces  160 - 164  and connecting elements  112 ,  114  are shown between base part  102  and swiveling part  104 . These are present, however, in analogous manner to the specific embodiment of  FIG. 1 . In the present specific embodiment, in second suspension region  134  the positions of electrode blocks  144 ′,  146 ′ are exchanged, relative to the position of electrode blocks  144 ,  146  in the first suspension region. By the independent activation either of electrode blocks  144 ,  146  in first suspension region  132 , or of electrode blocks  144 ′,  146 ′ in second suspension region  134 , mirror  122  is able to be deflected about axis  136  in different swiveling directions. 
       FIG. 5  shows a micromechanical component in a summary-type top view, according to an additional specific embodiment. For the sake of clarity, no printed circuit traces  160 - 164  are shown. These are present, however, in an analogous manner to the specific embodiment of  FIG. 1 . In the present specific embodiment, in each of suspension regions  132 ,  134  electrode blocks of base part  102  are facing each other pairwise. Mirror frame  128  is suspended as swiveling part  104  between two torsional springs  112 ,  114 , which in each of suspension regions  132 ,  134  extend along the entire center line between the electrode blocks of base part  102  that face one another pairwise. Movable plate electrodes  140  are suspended on torsional springs  112 ,  114 , which are able to be swiveled in both directions about axis  136 , depending on the control. 
     Two insulating trenches  106  are developed on mirror frame  128 , which insulate a first section  108  and a second section  110  of mirror frame  128 , that is able to be swiveled, from each other. Analogous insulating trenches  116  insulate a first base part section  118  and a second base part section  120  from each other. In this way, torsional springs  112 ,  114  are electrically insulated from each other, which makes possible to connect movable plate electrodes  140 ,  140 ′ in the two suspension regions  132 ,  134  in a different manner, for instance, by using plate electrodes  140  for driving and plate electrodes  140 ′ for position detection. In addition, mirror  122  and, if necessary, electrodes developed on its backside may be electrically operated via frame torsional spring  114  and mirror torsional springs  124 . 
       FIG. 6  shows a flow chart of a production method for a micromechanical component according to one specific embodiment. In Step  600 , an SOI wafer made of an oxide material is provided, having a thick substrate layer, a thinner overlayer and an insulating intermediate layer. Such a wafer may be commercially procured, for example, or produced using known methods, such as via the SIMOX method or the epitaxial application of polysilicon on an oxide layer. 
     In Step  602 , additional electrical elements, such as piezoresistant elements, are applied optionally onto the overlayer, for instance, using usual semiconductor processes. 
     In Step  604 , after applying and patterning a suitable etching mask, an insulating trench is etched into the overlayer up to the intermediate layer, using an isotropically acting etching method, so that the insulating trench insulates a first and a second section of the overlayer laterally from each other. Furthermore, point-for point etching may take place at locations at which contacts between the overlayer and the substrate are to be developed. 
     In Step  606 , a continuous insulating layer  306  is applied, which continuously covers the surface of the overlayer and also the inside of the insulating trenches etched in Step  604  or the depressions etched point-by-point in Step  604 . 
     In Step  608 , insulating layer  306 , that was applied in Step  606 , is opened at such locations, towards the overlayer, at which a contact is to be developed between a printed circuit trace and the overlayer. At locations at which a contact is to be developed between the overlayer and the substrate, or between a printed circuit trace and the substrate, at the bottom of depressions which were etched in Step  604  down to the intermediate layer, insulating layer  306  and, if necessary, the intermediate layer still lying under it, are opened all the way to the substrate. 
     In Step  610  a metallic layer is applied and patterned, in order to develop printed circuit traces and terminal pads such as soldering eyelets, at the places at which the insulating layer and, if necessary, the intermediate layer were opened, a corresponding contact being produced between the printed circuit traces, the overlayer or the substrate. 
     In Step  612 , starting from the substrate side of the wafer, comb electrodes are etched using a trench etching method, an insulating trench in the substrate, reaching up to the insulating intermediate layer, separating a region of a base part and a region of a swiveling part, that is to be developed to be swiveled with respect to the base part, from each other. 
     In Step  614 , starting from the side of the overlayer, using a suitable trench etching method between the regions of the base part and the swiveling part, at least two connecting elements such as bending beams or torsional springs are developed from the conductive material of the overlayer, namely, in such a way that the base part is connected via one of the connecting elements to the first swiveling part section, and via an additional one of the connecting elements to the second swiveling part section. The exposed intermediate layer is removed at suitable locations in such a way that the base part and the swiveling part are still connected only at the connecting elements, and are able to be swiveled elastically with respect to each other.