Method for producing a wafer equipped with transparent plates

A production method for a wafer equipped with transparent plates includes: formation of a row of through-holes in a wafer; formation of at least one strip-shaped recess in a wafer surface, each of the through-holes of the same row intersecting partly with the respectively associated strip-shaped recess; an uninterrupted groove being formed in each intermediate region between two adjacent through-holes of the same row, the floor surface of the groove being oriented so as to be inclined relative to the wafer surface by an angle of inclination greater than 0° and less than 90°; and covering at least one through-hole with at least one transparent plate made of at least one material transparent to at least a sub-spectrum of electromagnetic radiation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for producing a wafer equipped with transparent plates. The present invention also relates to a method for producing a covering cap for a micromechanical component. In addition, the present invention relates to a wafer and to a covering cap for a micromechanical component.

2. Description of the Related Art

In published German patent application document DE 10 2008 040 528 A1, a production method is described for a micromechanical component, and a correspondingly produced micromechanical component is described. The micromechanical component includes a chip having an adjustable reflective plate and a housing designed to accommodate the chip, having an incident light window. The incident light window can be situated on a covering cap of the housing in such a way that, relative to an external side of the covering cap oriented away from the chip and from the reflective plate in its initial position, the incident light window is oriented with an angle of inclination not equal to 0° and not equal to 180°.

BRIEF SUMMARY OF THE INVENTION

The present invention enables a mechanical production of a multiplicity of attachment surfaces for attaching at least one transparent plate in a position that is inclined relative to the wafer surface, in a single working step/process step. The conventionally executed sequential processing out of a single attachment surface for only one transparent plate on a wafer can thus be replaced by the present invention. The simultaneous mechanical processing of a complete chip row that can be realized by the present invention significantly reduces the production time required to produce a wafer equipped with transparent plates, or to produce a covering cap structured out therefrom for a micromechanical component. Correspondingly, the present invention makes it possible to produce wafers and covering caps for a micromechanical component at lower cost.

Moreover, the present invention enables the use of a milling or grinding pin having a larger outer diameter compared to the tool that can be used in the existing art. In this way, the present invention also increases the operating life of the mechanical tool that is used, resulting in a savings cost. Moreover, the present invention also permits the use of a saw, which was not possible in the existing art.

In an advantageous specific embodiment of the production method, the at least one strip-shaped recess is fashioned in the wafer surface in each case going out from a first segment of a side edge of the wafer up to a second segment of the side edge of the wafer. Such a process can be carried out quickly and reliably, for example using a relatively low-cost saw.

In a particularly low-cost specific embodiment that is easy to realize, at least two through-holes that are adjacent to one another and that intersect with the same strip-shaped recess are covered by the same transparent plate. In particular, a row of through-holes that intersect with the same strip-shaped recess can be covered by only one transparent plate. The covering of a multiplicity of through-holes can therefore take place in one working step by attaching a single transparent plate. The specific embodiment described here of the production method thus significantly reduces the production time. Moreover, this specific embodiment of the production method permits the use of a comparatively large transparent plate, and thus reduces the demands made on the apparatus that can be used to attach the transparent plate.

For example, the at least one through-hole can be covered by at least one optical window, at least one UV window, at least one window having an anti-reflective coating, at least one lens, at least one prism, and/or at least one filter, as the at least one transparent plate. The finally produced wafer can thus be used for a large number of possible applications.

In particular, the at least one transparent plate can be fastened on the at least one through-hole by a fastening means. This can take place in such a way that the at least one through-hole is hermetically sealed by the fastening means and by the at least one transparent plate. The finally produced wafer, or the covering caps structured out therefrom, can thus also be used for an airtight packing of a multiplicity of micromechanical components. For example, in this way a partial vacuum can be realized in the respectively packaged micromechanical component.

In an advantageous development, an outer side, oriented toward the wafer surface, of the at least one transparent plate can be covered with at least one protective lacquer. In this way, damage to the at least one transparent plate can be prevented during transport and/or during further processing of the wafer. Moreover, the at least one protective lacquer can prevent damage or contamination of the at least one transparent plate during structuring out of covering caps from the finally produced wafer.

The advantages stated above are also ensured in a corresponding production method for a covering cap.

The advantages stated above are also realized by a wafer having at least one row of through-holes fashioned in the wafer, and having at least one strip-shaped recess fashioned in a wafer surface of the wafer, each of the through-holes of the same row partly intersecting with the respectively associated strip-shaped recess, and an uninterrupted groove being fashioned in each intermediate region between two adjacent through-holes of the same row, the floor surface of said grooves being inclined to the wafer surface at an angle greater than 0° and less than 90°, and the at least one through-hole being covered by at least one transparent plate made of at least one material that is transparent at least to a sub-spectrum of electromagnetic radiation. The wafer can be further developed according to the specific embodiments described above.

In addition, the advantages are also ensured in the case of a covering cap for a micromechanical component having a bearer element structured out from a wafer, having at least one through-hole on a bearer element side, the hole being covered by at least one transparent plate made of at least one material that is transparent to at least a sub-spectrum of electromagnetic radiation, the bearer element side having at least one uninterrupted groove structured out from an edge of the bearer element side on which the bearer element is structured out from the wafer, running to the single through-hole fashioned on the bearer element side, or to one of the through-holes fashioned on the bearer element side, and a floor surface of the at least one uninterrupted groove being inclined relative to the bearer element side at an angle of inclination greater than 0° and less than 90°. The covering cap can also be further developed according to the above-described specific embodiments.

DETAILED DESCRIPTION OF THE INVENTION

In the method described here, at least one row of through-holes10is fashioned in a wafer12. Here, a through-hole10is understood as an opening going through wafer12. This can also be described by saying that through-holes10extend from a first wafer surface14aof wafer12to a second wafer surface14boriented away from first wafer surface14a. Preferably, first wafer surface14ais oriented parallel to second wafer surface14b.

Wafer12, used to carry out the method described here, is preferably a semiconductor wafer. In particular, wafer12can be a silicon wafer. However, it is to be noted that the practicability of the method described here is not limited to a particular material of wafer12.

Through-holes10can for example be etched through wafer12. In the case of a wafer12made of silicon, the formation of the at least one row of through-holes10can take place for example via KOH etching (potassium hydroxide etching). In order to form through-holes10, however, a multiplicity of other etching materials may also be used. Likewise, the formation of the at least one row of through-holes10can also be accomplished mechanically, e.g. by boring.

Preferably, through-holes10fashioned in a row are situated relative to one another in such a way that for their surfaces of intersection with a plane running through first wafer surface14a, mid-points (not shown) can be defined that are situated on a line A-A′. The lines A-A′ of a plurality of rows of through-holes10can run parallel to one another. In particular, through-holes10of a plurality of rows can form a grid. In this case, the mid-points of the intersecting surfaces (of through-holes10of different rows with the plane running through first wafer surface14a) are also situated on lines B-B′. Preferably, the lines B-B′ are oriented perpendicular to the lines A-A′ that run parallel to one another. The configuration of through-holes10shown inFIG. 1Ais however to be regarded only as an example.

In the specific embodiment described here, through-holes10having a rectangular cross-section are fashioned along a sectional plane running parallel to first wafer surface14a. All through-holes10of the same row for example have two side walls10aand10boriented perpendicular to the line A-A′, the walls being oriented perpendicular to first wafer surface14aand to second wafer surface14b. In contrast, only one side wall10cper through-hole10, fashioned parallel to line A-A′ of the associated row of through-holes10, is oriented perpendicular to first wafer surface14aand to second wafer surface14b. Another side wall10dper through-hole10, running parallel to line A-A′, is oriented at an angle greater than 0° and less than 90° to first wafer surface14aand to second wafer surface14b. It is to be noted that through-holes10, even without a rectangular cross-section, can each have a side wall10drunning parallel to the line A-A′ of their row, the wall being oriented to first wafer surface14aand to second wafer surface14bat an angle greater than 0° and less than 90°. In addition to side wall10d, oriented at an angle to wafer surfaces14aand14b, each of the through-holes10, without a rectangular cross-section, can also have a side wall10crunning parallel to line A-A′ of its row, said wall running perpendicular to first wafer surface14aand to second wafer surface14b.

Through-holes10can for example all be fashioned having the same first (minimum) through-hole width b1along their associated line A-A′ (and parallel to first wafer surface14a), and/or having the same second (minimum) through-hole width b2perpendicular to their associated line A-A′ (and parallel to first wafer surface14a). Through-holes10can however also have different through-hole widths b1and b2.

In a further method step, optionally carried out before or after the formation of the at least one row of through-holes10in wafer12, at least one strip-shaped recess16is fashioned in first wafer surface14aof the wafer. Preferably, a strip-shaped recess16is formed in first wafer surface14afor each row of through-holes10.

The formation of the at least one strip-shaped recess16in first wafer surface14aof wafer12is accomplished using a mechanical tool.

Preferably, for this purpose a relative movement is carried out between the mechanical tool and wafer12. During the relative movement between the mechanical tool and wafer12, carried out in order to form exactly one strip-shaped recess, the mechanical contact is maintained between the processing surface of the mechanical tool and wafer12. This can be understood for example as meaning that, during the formation of exactly one strip-shaped recess16, the same part of the processing surface of the mechanical tool is in uninterrupted mechanical contact with wafer12. Alternatively, during the formation of exactly one strip-shaped recess16, a new part of the processing surface of the mechanical tool can continuously contact wafer12in such a way that the mechanical contact between the processing surface of the mechanical tool as a whole and the wafer is never interrupted.

The processing surface of the mechanical tool is understood to be a surface of the mechanical tool that, through mechanical contact with wafer12, brings about a removal of wafer material from first wafer surface14aof wafer12. As a rule, the processing surface of the mechanical tool is held/pressed on first wafer surface14ain such a way that friction occurs between the processing surface and the wafer material, resulting in the desired removal of the wafer material from first wafer surface14aof wafer12. Examples of a mechanical tool that can be used are described further below.

In the method described here, the formation of the at least one row of through-holes10and the formation of the at least one strip-shaped recess16are matched to one another in such a way that each of the through-holes10of the same row partly intersects with the respectively associated strip-shaped recess16, and an uninterrupted groove18is formed in each intermediate region20between two adjacent through-holes10of the same row (which intersect with the same strip-shaped recess16). The respective uninterrupted groove18extends without interruption from a first through-hole10of the two adjacent through-holes10up to a second through-hole10of the two adjacent through-holes10. In the formation of each uninterrupted groove18, floor surface18athereof is oriented so as to be inclined to first wafer surface14a. This is to be understood as meaning that floor surface18aof each uninterrupted groove18is oriented at an angle of inclination α to first wafer surface14athat is greater than 0° and less than 90°. Preferably, floor surface18aof each uninterrupted groove18is fashioned so as to be inclined, in a direction oriented perpendicular to the relative movement, by the angle of inclination α relative to first wafer surface14athat is greater than 0° and less than 90°. Preferably, floor surface18aof each uninterrupted groove18is also (in particular in a direction oriented perpendicular to the relative movement) fashioned with the same angle of inclination α to second wafer surface14b, greater than 0° and less than 90°. (Floor surface18ais understood as a wafer material surface, oriented away from first wafer surface14a, on the respective uninterrupted groove18.)

The formation of the at least one strip-shaped recess16can take place via grinding, milling, and/or sawing. For each strip-shaped recess16, a floor surface16ais ground, milled, or sawed, this floor surface also being fashioned so as to be inclined to first wafer surface14awith an angle of inclination α greater than 0° and less than 90°.

In the specific embodiment described here, first through-holes10are fashioned in wafer12(seeFIG. 1A through 1C). InFIGS. 1D through 1F, the broken lines show the positions, longitudinal extension(s) L, and width(s) Bh of strip-shaped recesses formed after through-holes10. The at least one strip-shaped recess16preferably has (along its respectively associated line A-A′) a longitudinal extension L that is greater than a maximum extension Am of the row, intersecting therewith, of through-holes10along the line A-A′ of the row. In order to form a respective strip-shaped recess16, a (previously formed) row of through-holes10is gone over with (in each case at least a part) of the processing surface of the mechanical tool without interrupting the mechanical contact between the processing surface of the mechanical tool and wafer12in the meantime/during the formation of strip-shaped recess16. The mechanical contact between the processing surface of the mechanical tool and wafer12can be (briefly) interrupted only between a formation of a first strip-shaped recess16and a subsequent formation of a second strip-shaped recess16on the same wafer12.FIGS. 1G through 1Ishow wafer12after the formation of the at least one row of through-holes10, and after the subsequent formation of the at least one strip-shaped recess16.

The formation of the at least one strip-shaped recess16in first wafer surface14acan however also take place after a formation/etching of the at least one row of through-holes10. In this case, first the at least one strip-shaped recess16is formed in first wafer surface14a, for which purpose first wafer surface14ais preferably gone over by the processing surface of the mechanical tool the same number of times as the number of strip-shaped recesses16that are to be formed in first wafer surface14a. During the going over of first wafer surface14awith (at least a part) of the processing surface of the mechanical tool, the processing surface remains in (uninterrupted) mechanical contact with wafer12. The mechanical contact between the processing surface of the mechanical tool and wafer12can be (briefly) interrupted only between a formation of a first strip-shaped recess16and a subsequent formation of a second strip-shaped recess16on the same wafer12. Subsequently, for each strip-shaped recess16that is fashioned, a row of through-holes10is formed in such a way that the row of through-holes10partly intersects with the associated strip-shaped recess16. Preferably, the at least one row of through-holes10is fashioned having a maximum extension Am (along the line A-A′ of the row), which is smaller than a longitudinal extension L of the associated recess16(along the respective line A-A′).

It is again to be noted that in the two above-described process sequences, in each intermediate region20between two adjacent through-holes10of the same row a respective uninterrupted groove18is fashioned with its floor surface18asituated at an incline to first wafer surface14a. If the maximum extension Am of a row of through-holes10is smaller than the longitudinal extension L of the associated strip-shaped recess16, the outer through-holes10of the same row of through-holes10have, at their sides oriented away from adjacent through-hole10, outer grooves24whose floor surfaces24aare also oriented at an inclination to first wafer surface14awith angle of inclination α greater than 0° and less than 90°. (Floor surface24aof an outer groove24is understood as a wafer material surface, oriented away from first wafer surface14a, on respective outer groove24.) Specifically, outer grooves24can also extend up to an adjacent side edge14cof wafer12(between wafer surfaces14aand14b).

Preferably, the at least one strip-shaped recess16is formed having a width Bh, perpendicular to the associated longitudinal extension, that is larger than the second (minimum) through-hole width b2(oriented perpendicular to maximum extension A of the associated row of through-holes10) of through-holes10. In this way, at through-holes10, adjacent to first wafer surface14a, a first widening region25aand a second widening region25bare further formed that extend parallel to associated line A-A′, and between which the contacted through-hole10is situated. Widening regions25aand25balso have floor surfaces that are oriented at an angle to first wafer surface14aby the angle of inclination α greater than 0° and less than 90° and in the following are designated support surfaces26aand26bfor at least one transparent plate. (Support surfaces26aand26bare also oriented at an inclination to second wafer surface14bby angle of inclination α greater than 0° and less than 90°.)

Preferably, the at least one strip-shaped recess16is fashioned in each case going out from a first segment of side edge14cof wafer12up to a second segment of side edge14cof wafer12in first wafer surface14a. By going over first wafer surface14aat least once with the mechanical tool, in this way the at least one strip-shaped recess16can be fashioned comparatively easily and quickly.

In a further method step, the at least one through-hole10is covered by at least one transparent plate28. The at least one transparent plate28is understood to be a covering element that is made of at least one material that is transparent at least to a sub-spectrum of electromagnetic radiation. The at least one transparent plate28thus has, for at least the sub-spectrum of electromagnetic radiation, a comparatively high transmission coefficient, or a relatively low coefficient of reflection. For example, the at least one through-hole10can be covered by at least one optical window, at least one UV window, at least one window having an anti-reflective coating, at least one lens, at least one prism, and/or at least one filter, as the at least one transparent plate28. Wafer12produced by the method described here is thus suitable for a large number of possible applications.

The at least one transparent plate28can be fastened/glued to the at least one through-hole10using at least one fastening means/joining means (not shown). For example, before placing the at least one transparent plate28into the at least one strip-shaped recess16, the fastening means/joining means can be deposited on the at least one transparent plate28. Alternatively, however, before attachment of the at least one transparent plate28, the fastening means/joining means can also be deposited on the contact surface thereof fashioned on wafer12, e.g. at least on support surfaces26aand26b.

Preferably, the at least one through-hole10is hermetically sealed by the fastening means and by the at least one transparent plate28. A hermetic sealing of the at least one through-hole10is easy to realize due to the reliable ensuring of a smooth contact surface (such as support surfaces26aand26b) when carrying out the method described here.

For example, a glass solder (seal glass) can be used as a fastening means/joining means. If a glass solder is used as fastening means/joining means, wafer12can be heated after the attachment of the at least one transparent plate28and of the fastening means/joining means, whereby a hermetically sealed joint connection can be produced between the at least one transparent plate28and the material of wafer12. However, it is to be noted that for the fastening of the at least one transparent plate28it is also possible to use a multiplicity of glues, in particular hermetically sealing glues.

In the specific embodiment ofFIGS. 1J through 1L, each through-hole10is covered by a separate transparent plate28. The number of transparent plates28fastened on wafer12preferably corresponds to the number of through-holes10that are formed. However, in an alternative specific embodiment, at least two adjacent through-holes10intersecting with the same strip-shaped recess16are covered by the same transparent plate28. In particular, an entire row of through-holes10can be covered by a single (strip-shaped) transparent plate28. In this way, the covering of through-holes10can be carried out comparatively quickly.

Preferably, the at least one transparent plate28is placed in the at least one strip-shaped recess16in such a way that an outer side, oriented away from the at least one covered through-hole10, of transparent plate28does not protrude from first wafer surface14a. In particular, a position for the outer side of the at least one transparent plate28is preferred that is inwardly offset relative to first wafer surface14a. This is easy to realize via a suitable choice of a maximum layer thickness of the at least one transparent plate28, and a minimum depth of strip-shaped recess16.

FIGS. 1M through 1Oshow an optional method step in which a further wafer30is fastened on wafer12. Preferably, further wafer30is fixedly bonded or fixedly glued onto second wafer upper side14b. Further wafer30can be structured before the fastening. For example, at least one actuator device can be fashioned on further wafer30.

In a further optional method step, shown inFIGS. 1P through 1R, an outer side, oriented toward first wafer surface14a, of the at least one transparent plate28can be covered by at least one protective lacquer32. For this purpose, for example the at least one strip-shaped recess16can be filled with the liquid protective lacquer28, which is subsequently cured. Preferably, for this purpose a protective lacquer that can be stripped off without leaving a residue is used.

FIGS. 2A and 2Bshow schematic cross-sections through a wafer for the explanation of a second specific embodiment of the method for producing a wafer equipped with transparent plates, the cross-section ofFIG. 2Arunning along a scanning direction of a tool that is used, and the cross-section ofFIG. 2Brunning perpendicular to the scanning direction of the tool that is used.

In the specific embodiment shown inFIGS. 2A and 2B, an inclined cylindrical grinding or milling pin40is used as a tool for the formation of the at least one strip-shaped recess16in first wafer surface14aof depicted wafer12.

During operation of cylindrical grinding or milling pin40, its processing surface42rotates about an axis of rotation44. During a formation of a respective strip-shaped recess, a relative movement between cylindrical grinding or milling pin40and wafer12along a specified scanning direction46is carried out. This can take place via a movement of cylindrical grinding or milling pin40relative to (stationary) wafer12, or via a movement of wafer12relative to cylindrical grinding or milling pin40(held stationary). Moreover, during the formation of a respective strip-shaped recess16, cylindrical grinding or milling pin40(given an uninterrupted mechanical contact between at least a part of its processing surface42and wafer12) is held in such a way that axis of rotation44encloses, along scanning direction46, a right angle with first wafer surface14a(FIG. 2A), and, along an axis running perpendicular to scanning direction46and parallel to first wafer surface14a, encloses an angle of inclination α with first wafer surface14athat is greater than 0° and less than 90° (FIG. 2B).

FIGS. 3A and 3Bshow schematic cross-sections through a wafer for the explanation of a third specific embodiment of the production method for a wafer equipped with transparent plates, the cross-section ofFIG. 3Arunning along a scanning direction of a tool that is used, and the cross-section section ofFIG. 3Brunning perpendicular to the scanning direction of the tool that is used.

In the specific embodiment ofFIGS. 3A and 3B, in each case a row of through-holes10is gone over with a cylindrical saw blade50of a saw52. Cylindrical saw blade50(used as processing surface) rotates about an axis of rotation54during operation of saw blade50. In this specific embodiment as well, for the formation of a respective strip-shaped recess16a relative movement is carried out between cylindrical saw blade50and wafer12along a scanning direction56. Optionally, this can take place via a movement of saw blade50/saw52relative to (stationary) wafer12, or via a movement of wafer12relative to (stationary) saw blade50/saw52held stationary. In addition, during the formation of the respective strip-shaped recess16, cylindrical saw blade50can be held in uninterrupted mechanical contact with wafer12. In addition, during the formation of the respective strip-shaped recess16(and during the contact of saw blade50with wafer12), saw52can be held in such a way that axis of rotation54is oriented so as to be inclined to first wafer surface14aby an angle of inclination α greater than 0° and less than 90° (FIG. 3B), a projection of axis of rotation54and a projection of scanning direction56onto first wafer surface14abeing oriented perpendicular to one another.

FIGS. 4A and 4Bshow schematic cross-sections through a wafer for the explanation of a fourth specific embodiment of the production method for a wafer equipped with transparent plates, the cross-section ofFIG. 4Arunning along a scanning direction of a tool that is used, and the cross-section ofFIG. 4Brunning perpendicular to the scanning direction of the tool that is used.

In the specific embodiment ofFIGS. 4A and 4B, a saw60is used having a frustum-shaped saw blade62, frustum-shaped saw blade62rotating about an axis of rotation64during operation of saw60. For each strip-shaped recess16, a respective relative movement is executed between saw60and wafer12along a scanning direction66. Optionally, this can take place via a movement of saw blade62/saw60relative to (stationary) wafer12, or via a movement of wafer12relative to saw blade62/saw60. In this specific embodiment as well, frustum-shaped saw blade62is held in uninterrupted mechanical contact with wafer12during the formation of each strip-shaped recess16. In addition, during the formation of each strip-shaped recess16(and during the contact of saw blade62with wafer12), saw60is held in such a way that axis of rotation64is oriented parallel to first wafer surface14a, a projection of axis of rotation54and a projection of scanning direction56onto first wafer surface14abeing oriented perpendicular to each other. Due to the inclined profile of frustum-shaped saw blade62, in this way the desired inclined floor surface16aof strip-shaped recess16is formed automatically.

A wafer12produced by one of the above-described methods is recognizable by at least one row of through-holes10fashioned in wafer12, and at least one strip-shaped recess16fashioned in a wafer surface14aof wafer12, each of the through-holes10of the same row intersecting partly with the respectively associated strip-shaped recess16, and an uninterrupted groove18being fashioned in each intermediate region20between two adjacent through-holes10of the same row, the floor surface18aof this groove being oriented so as to be inclined to wafer surface14aby an angle of inclination α greater than 0° and less than 90°, and the at least one through-hole10being covered by at least one transparent plate28made of at least one material that is transparent at least to a sub-spectrum of electromagnetic radiation.

It is to be noted that wafer12produced by the advantageous technology described herein is equipped with at least one transparent plate28whose outer surface and whose inner surface are inclined relative to first wafer surface14a(and preferably also relative to second wafer surface14b) by the angle of inclination α greater than 0° and less than 90°. The inclination of the outer surface and inner surface of the at least one transparent plate28acts, during later use of a covering cap obtained from wafer12, to screen out disturbing reflections from an image surface.

FIGS. 5Athough5F show schematic representations of a wafer for the explanation of a specific embodiment of the production method for a covering cap for a micromechanical component,FIGS. 5A and 5Dshowing top views of the wafer,FIGS. 5B and 5Eshowing cross-sections along the line A-A′ inFIGS. 5A and 5D, andFIGS. 5C and 5Fshowing cross-sections along the line B-B′ inFIGS. 5A and 5D.

In order to carry out the production method described here, first a wafer12equipped with transparent plates28is produced. For this purpose, the already-described method steps of the production method for a wafer12equipped with transparent plates28can be carried out.

Subsequently, as shown inFIGS. 5A through 5C, the (at least one) covering cap70is structured out from wafer12equipped with transparent plates28. This takes place for example in that first an adhesive tape72is affixed onto first wafer surface14aof wafer12, which tape also contacts the at least one cured protective lacquer32. The adhesive tape72that is used can for example be a blue tape or a UV tape. Subsequently, in the specific embodiment ofFIGS. 5A through 5C, covering caps70are sawed out from wafer12. During this separation, the at least one protective lacquer32prevents sawdust from traveling via saw lines73and strip-shaped recess16onto the at least one transparent plate28. Thus, during the separation, no contamination by sawdust will occur of the at least one transparent plate28. (The at least one protective lacquer preferably fills all gaps between adhesive tape72and wafer12.)

Subsequently, as shown inFIGS. 5D through 5F, separated covering caps70are picked off from adhesive tape72. During the picking off of the separated covering caps70from adhesive tape72, the at least one cured protective lacquer32(automatically) remains on adhesive tape72. The at least one protective lacquer32can thus be removed comparatively easily without leaving a residue.

The finally produced covering caps70can subsequently be used to cap a micromechanical component, such as for example a micro-mirror.

FIG. 6shows a schematic representation of a specific embodiment of the covering cap for a micromechanical component.

Covering cap70shown schematically inFIG. 6can be used to cap a micromechanical component. Covering cap70enables in particular a hermetically sealed wafer level packaging.

Covering cap70includes a bearer element74structured out from a wafer, having on a bearer element side76at least one through-hole10that is covered by at least one transparent plate28made of at least one material that is transparent at least to a sub-spectrum of electromagnetic radiation. Moreover, bearer element side76has at least one uninterrupted groove18that runs from an edge78of bearer element side76, at which reflective element74is structured out from the wafer, to the single through-hole10fashioned on bearer element side76, a floor surface18aof the at least one uninterrupted groove18being oriented at an inclination to bearer element side76by an angle of inclination α greater than 0° and less than 90°. In the specific embodiment shown inFIG. 6, two such grooves18, whose boundaries are shown by dashed lines80, are fashioned on bearer element side76. If, however, a plurality of through-holes are fashioned in bearer element74, the at least one uninterrupted groove18can also extend from edge78of bearer element side76, at which bearer element74is structured out from the wafer, to one of the through-holes10fashioned on bearer element side76, and in this case as well floor surface18aof the at least one uninterrupted groove18is oriented at an inclination to bearer element side76by an angle of inclination α greater than 0° and less than 90°. In both cases, due to the at least one uninterrupted groove18, it can be recognized that covering cap70has been produced according to the method described above or a variant thereof. (With regard to further properties of covering cap70, reference is made to the above statements.)

After the capping of a micromechanical component with covering cap70, the at least one transparent plate28ensures an entry and/or exit of a light beam into the micromechanical component packed by covering cap70. The micromechanical component preferably includes a (possibly adjustable) reflective element that can easily be configured in such a way that its reflective surface, at least in its initial position, is oriented so as to be inclined relative to the at least one transparent plate28. This can be used for the (automatic) screening out of disturbing reflections from an image surface.