TWI688542B - Laser reseal with local delimitation - Google Patents

Abstract

A method is provided for producing a micromechanical component having a substrate and having a cap which is connected to the substrate and encloses a first cavity with the substrate, a first pressure prevailing and a first gas mixture having a first chemical composition being enclosed in the first cavity, - an access opening connecting the first cavity to an environment of the micromechanical component being formed in the substrate or in the cap in a first method step, - the first pressure and/or the first chemical composition in the first cavity being adjusted in a second method step, - the access opening being sealed by introducing energy or heat into an absorbent part of the substrate or of the cap with the aid of a laser in a third method step, wherein - a structure raised relative to a surface, facing away from the first cavity, of the substrate or of the cap and arranged in the region of the access opening is formed in a fourth method step in order to provide a material region of the substrate or of the cap which is converted into a liquid state of aggregation in the third method step.

Description

Laser reclosure with local delimitation

The present invention relates generally to laser reclosing with local delimitation.

The present invention is based on a method according to the preamble of item 1 of the patent application.

Such a method is known from WO 2015/120939 A1. If a specific internal pressure in the cavity of the micromechanical component is required, or if a gas mixture with a specific chemical composition is to be enclosed in the cavity, it is often during the capping of the micromechanical component or in the substrate wafer and cap The internal pressure or chemical composition is adjusted during the bonding process between wafers. During capping, for example, the cap is connected to the substrate, so that the cap encloses the cavity together with the substrate. By adjusting the chemical composition of the atmosphere or pressure and/or gas mixture present in the environment during capping, the specific internal pressure and/or specific chemical composition in the cavity can be adjusted accordingly.

By the method known from WO 2015/120939, the internal pressure in the cavity of the micromechanical component can be adjusted in a controlled manner. By this method, it is particularly possible to produce a micromechanical component with a first cavity, it is possible to adjust the first pressure and the first chemical composition in the first cavity (which are different from the second pressure and the second pressure when capping, respectively) The second chemical composition).

In a method according to WO 2015/120939 A1 for adjusting the internal pressure in the cavity of a micromechanical component in a controlled manner, in a cap, or in a cap wafer, or in a substrate , Or create a narrow access channel to the cavity in the sensor wafer. Subsequently, the cavity is filled with the desired gas and the desired internal pressure through the access channel. Finally, the area around the access channel is locally heated by laser, and the substrate material is locally liquefied, and the access channel is hermetically closed when it solidifies.

An object of the present invention is to provide a method for manufacturing a micromechanical component in a simple and economical manner compared to the prior art, which is mechanically stable and has a longer life compared to the prior art. Another object of the present invention is to provide a micromechanical component which is compact and mechanically stable and has a longer life compared to the prior art. According to the invention, this applies in particular to micromechanical components with (first) cavities. With the method according to the invention and the micromechanical component according to the invention, it is also possible to manufacture the first pressure and the first chemical composition that can be adjusted in the first cavity and the second pressure and the first pressure that can be adjusted in the second cavity 2. Micro-mechanical components of chemical composition. For example, providing such a method for manufacturing a micromechanical component is advantageous for enclosing a first pressure in a first cavity and enclosing a second pressure in a second cavity, the first pressure is given Different from this second pressure. This may be, for example, when it is intended to integrate the first sensor unit for rotation rate measurement and the second sensor unit for acceleration measurement into the micromechanical component.

This object is achieved by forming a structure that is raised relative to the surface of the substrate or the cap facing away from the first cavity in the fourth method step and is disposed in the area where the opening is taken to provide the substrate or The material area of the cap is converted into a liquid aggregate in the third method step.

With this method, a method for manufacturing a micromechanical component is provided in a simple and economical manner, by which a region of material after solidification can be generated such that it faces away from the first cavity with respect to the back of the substrate or the cap The other surface is lowered. Compared to methods that do not form this structure, the method according to the invention has the advantage that, for example, the solidified material area protrudes less than the other surface, so that the solidified material area provides less bonding area for mechanical impact. In this way, the solidified material area and/or the interface between the solidified material area and the rest of the substrate or the rest of the cap and/or the area around the interface are less likely to form cracks. In other words, with the aid of the method according to the invention, the solidified material area (for example) is less susceptible to damage during the manufacturing process and is less prone to unintended contact, and therefore also less cause and starting point of cracks. Therefore, a method for manufacturing a micromechanical component that is mechanically stable and has a longer life compared to the prior art is provided in a simple and economical manner compared to the prior art.

Another advantage of the method according to the invention is that, by means of the raised portion, the absorption portion of the substrate or cap can be geometrically divided into the absorption of the first sub-portion and the absorption of the second sub-portion, so that the first sub-portion is arranged inside the structure And the second sub-portion is disposed in the surface area of the substrate or the cap. Due to the geometrically limited heat dissipation possibilities in the first sub-section compared to the heat dissipation possibilities in the second sub-section, it becomes possible (for example) to convert only the material areas in the first sub-section into liquid aggregates. In this way, by means of the structure, it can be advantageously made possible that the material area converted into liquid aggregates can already be determined geometrically by the geometry of the structure before laser radiation. Therefore, by the method according to the invention, a method is provided which is particularly robust with small changes in the alignment with respect to lasers with access holes.

Furthermore, with the method according to the invention, it is not a problem when only the substrate material is locally heated and the heated material shrinks both during solidification and during cooling relative to its environment. Even the fact that extremely high tensile stress can occur in the enclosed area is not a problem, because For example, the mechanically impacted joint area can be minimized by reducing the solidified material area. Therefore, it is unlikely to form spontaneous cracks depending on stress and material. It is also unlikely that cracks will form during further processing or in this area under the heat or mechanical load of the micromechanical components, because (for example) the closed access area is (for example) better protected.

According to the invention, "in the area of the access opening" is intended to mean that the substrate or the cap is directly adjacent to the area of the access opening. According to the invention, the structure is arranged in the area where the opening is taken. Furthermore, according to the present invention, an area where the substrate or the cap is separated from the receiving opening is provided. This separation area is, for example, arranged to be separated from the receiving opening in a direction perpendicular to the central axis of the receiving opening. In addition, the separation area (for example) is arranged directly adjacent to the area where the opening is taken. In this case, for example, it is prescribed that the surface is arranged at least partially in the separation area.

Furthermore, according to the present invention, the "absorption portion of the substrate or cap" is intended to mean the area of the substrate or cap where 90% of the energy or heat absorption in the substrate or cap occurs.

In conjunction with the present invention, the term "micromechanical component" should be understood to mean a term covering both micromechanical components and microelectromechanical components.

The present invention is preferably intended for the manufacture of micromechanical components with cavities or for micromechanical components with cavities. However, the present invention is, for example, also intended for micromachines having two cavities or having more than two cavities (ie, three, four, five, six, or more than six cavities) Components.

Preferably, the access opening is closed by introducing energy or heat into the energy absorption portion or heat absorption portion of the substrate or cap by means of laser. In this case, it is preferable to introduce energy or heat into the absorption portions of the substrates or caps of the plurality of micromechanical components, which are produced together on a wafer, for example, in time sequence. However, as an alternative, For example, by using a plurality of laser beams or laser devices, energy or heat is simultaneously introduced into the respective absorption portions of the substrates or caps of the plurality of micromechanical components at the same time.

The advantageous configuration and improvement of the present invention can be found in the attached patent application scope and the description with reference to the drawings.

According to a preferred improvement, the cap and the substrate enclose a second cavity, a second pressure exists in the second cavity and a second gas mixture having a second chemical composition is enclosed in the second cavity in.

According to a preferred improvement, the structure is configured such that the solidified material region after the third method step is arranged substantially along the plane of the other surface of the substrate or cap extending away from the first cavity and the first cavity Between the cavities. This advantageously makes it possible that the solidified material area does not protrude beyond the other surface, so that the solidified material area provides a less mechanically impacted joint area. By means of this, the solidified material region and/or the interface between the solidified material region and the rest of the substrate or the rest of the cap and/or the area around the interface are even less likely to form cracks.

According to a preferred improvement, the structure is configured such that the solidified material region after the third method step is arranged substantially along a plane extending substantially along the other surface of the substrate or cap facing away from the first cavity This surface extends between another plane. This advantageously makes it possible to produce micromechanical components that are particularly stable against mechanical shocks.

According to a preferred improvement, the structure is configured such that the first area of the structure to the protrusion on another plane extending substantially along the surface is smaller than the area of the solidified material region to the protrusion on the other plane The second area is/and is smaller than the third area of the absorbing portion of the substrate or the cap to the protrusion on the other plane. This can advantageously make it possible to adjust the energy or heat introduced by the laser into the substrate or cap in a controlled manner by means of the geometry of the structure. Furthermore, it is advantageous to provide a method with particularly high energy or heat introduction accuracy compared to the prior art.

According to a preferred improvement, the structure is arranged symmetrically and/or annularly with respect to the access opening and/or to the center of mass of the solidified material region and/or to the absorption portion of the substrate or cap The state lies in another plane extending substantially parallel to the surface. This makes it possible for material regions converted into liquid aggregates to flow particularly advantageously.

According to a preferred improvement, the structure in the third plane extending substantially parallel to the surface is substantially separated from the midpoint of the access channel in the third plane. The maximum dimension of the configuration is the access channel in the third plane and The maximum scale of the midpoint separation configuration is at most six times or at most five times or at most four times or at most three times or at most twice. This makes it possible for the material areas converted into liquid aggregates to flow particularly advantageously. For example, this advantageously makes it possible for the material region to flow in such a way that the solidified material region after the third method step is arranged in a plane extending substantially along the other surface of the substrate or cap facing away from the first cavity With the first cavity.

In addition, the present invention relates to a micromechanical component having a substrate and having a cap connected to the substrate and enclosing a first cavity with the substrate, a first pressure exists in the first cavity and has The first gas mixture of the first chemical composition is enclosed in the first cavity, and the substrate or the cap includes a closed access opening, wherein the substrate or the cap includes a portion opposite to the substrate or the cap A structure of the surface of a cavity raised and arranged in the area of the access opening to provide a material area of the substrate or the cap, which material area is converted into a liquid aggregate during the closing of the access opening. In this way, it is advantageous to provide a compact, mechanically stable and economical micromechanical component with an adjusted first pressure. Before the method of the present invention The advantages mentioned above also apply correspondingly to the micromechanical component according to the invention.

According to a preferred improvement, the structure is configured such that the solidified material region after closing the access opening is arranged substantially along the plane and the first surface of the substrate or the cap extending away from the other surface of the first cavity Between a cavity. In this way, it is advantageous to provide micromechanical components that are particularly stable against mechanical shocks.

According to a preferred improvement, the structure is configured such that the solidified material region after closing the access opening is arranged on a plane and substantially extending along the other surface of the substrate or the cap facing away from the first cavity Between the other planes extending along the surface. In this way, it is advantageous to provide micromechanical components that are particularly stable against mechanical shocks.

According to a preferred improvement, the structure is configured such that the first area of the structure to the protrusion on another plane extending substantially along the surface is smaller than the area of the solidified material region to the protrusion on the other plane The second area is/and is smaller than the third area of the absorbing portion of the substrate or the cap to the protrusion on the other plane.

According to a preferred improvement, the structure is substantially rotationally symmetrical and/or ring-shaped with respect to the access opening and/or with respect to the center of mass of the solidified material area and/or with respect to the absorption portion of the substrate or the cap It is arranged in another plane extending substantially parallel to the surface. This advantageously makes it possible for the maximum stress to be farther from the access channel and less concentrated compared to micromechanical components known from the prior art. Furthermore, it is thereby advantageously possible to achieve the effect that the solidified material region is configured only below another plane which extends substantially along the surface.

According to a preferred improvement, the structure in the third plane extending substantially parallel to the surface is substantially separated from the midpoint of the access channel in the third plane. The maximum dimension of the configuration is the access channel in the third plane and At most six times or at most five times the maximum scale of this midpoint separation configuration Or at most four times or at most three times or at most twice.

According to a preferred improvement, the substrate and/or the cap comprise silicon. This advantageously makes it possible to manufacture micromechanical components by means of manufacturing methods known from the prior art.

According to a preferred improvement, the cap and the substrate enclose a second cavity, a second pressure exists in the second cavity and a second gas mixture having a second chemical composition is enclosed in the second cavity in. In this way, it is advantageous to provide a compact, mechanically stable and economical micromechanical assembly with adjusted first and second pressures.

According to a preferred improvement, the first pressure is lower than the second pressure, the first sensor unit for rotation rate measurement is arranged in the first cavity and the second sensor unit for acceleration measurement is arranged In the second cavity. In this way, it is advantageous to provide a mechanically stable micromechanical assembly with optimal operating conditions for the first sensor unit and for the second sensor unit for rotation rate measurement and acceleration measurement.

1‧‧‧Micromechanical components

3‧‧‧ substrate

5‧‧‧ First cavity

7‧‧‧block

9‧‧‧Environment

11‧‧‧Access opening/access hole

13‧‧‧Material area/Molten metal

15‧‧‧Horizontal

19‧‧‧surface

21‧‧‧ Absorption

101‧‧‧ First method steps

102‧‧‧ Second method steps

103‧‧‧ Third method steps

104‧‧‧ Fourth method step

205‧‧‧ Second cavity

211‧‧‧Laser radiation/laser pulse

213‧‧‧raised part/conical tip

1301‧‧‧Surface

1303‧‧‧Structure

1305‧‧‧plane

1307‧‧‧plane

1309‧‧‧Maximum scale

1311‧‧‧The third plane

1313‧‧‧ midpoint

1315‧‧‧Maximum scale

Fig. 1 shows a schematic illustration of a micromechanical assembly with an open access opening according to an illustrative embodiment of the invention.

FIG. 2 shows a schematic illustration of a micromechanical component closed according to the access opening of FIG. 1 .

Figure 3 shows a schematic illustration of a method for manufacturing a micromechanical component according to an illustrative embodiment of the present invention.

Figure 4 shows a schematic illustration of a known micromechanical component.

FIGS. 5, 6, 7, 8 and 9 show schematic representations of sub-regions of the micromechanical component according to FIG. 4 at different times in known manufacturing methods.

10, 11, 12, 12, 13, and 15 show schematic representations of sub-regions of a micromechanical component according to an illustrative embodiment of the present invention at different times in the method according to the present invention.

In the various drawings, the same components always have the same reference numerals, and therefore are usually only mentioned or mentioned once in each case.

FIG 1 and FIG 2 shows a schematic illustration of a micro-mechanical components of a specific example of an exemplary of the present invention of 1, the micromechanical component has an open acess opening 11 and has a closed in FIG. 2 connected in FIG. 1取开11。 Take the opening 11. In this case, the micromechanical component 1 includes the substrate 3 and the cap 7. The base plate 3 and the cap 7 are preferably connected to each other in an airtight manner, and together enclose the first cavity 5. For example, the micromechanical component 1 is configured such that the substrate 3 and the cap 7 additionally enclose the second cavity. However, the second cavity is not shown in FIGS. 1 and 2 .

For example, particularly in the acess opening 11 as in the case represented by 2 is closed, the first pressure present in the first cavity 5 in FIG. In addition, the first gas mixture with the first chemical composition is enclosed in the first cavity 5. In addition, for example, the second pressure exists in the second cavity, and the second gas mixture having the second chemical composition is enclosed in the second cavity. Preferably, the access opening 11 is arranged in the substrate 3 or the cap 7. In this illustrative specific example, as an example, the access opening 11 is arranged in the cap 7. However, according to the present invention, as an alternative thereto, it may also be provided that the access opening 11 is arranged in the substrate 3.

For example, it is specified that the first pressure in the first cavity 5 is lower than the second pressure in the second cavity. For example, the first micromechanical sensor unit (not shown in FIGS. 1 and 2 ) for rotation rate measurement is also provided in the first cavity 5 and the second The mechanical sensor unit (not shown in FIGS. 1 and 2 ) is disposed in the second cavity.

FIG. 3 shows a schematic illustration of a method for manufacturing a micromechanical component 1 according to an illustrative specific example of the present invention. In this case,-in a first method step 101, a particularly narrow access opening 11 is formed in the substrate 3 or cap 7 that connects the first cavity 5 to the environment 9 of the micromechanical component 1.

FIG. 1 shows the micromechanical component 1 after the first method step 101 by means of an example. In addition,-in the second method step 102, the first pressure and/or the first chemical composition in the first cavity 5 are adjusted, or the first cavity 5 is filled with the desired gas and the desired internal pressure via the access channel. In addition, for example,-in the third method step 103, energy or heat is introduced into the absorption portion of the substrate 3 or the cap 7 by the laser to close the access opening 11. As an alternative, for example, it is provided that-in the third method step 103, it is preferable to only locally heat the area around the access channel by laser, and to close the access channel in an airtight manner. Therefore, it may also be advantageous to provide other energy sources for the method according to the invention instead of the laser for closing the access opening 11. FIG. 2 shows the micromechanical component 1 after the third method step 103 by means of an example.

After the third method step 103 in chronological order, mechanical stresses can occur on the other surface 19 of the cap 7 facing away from the cavity 5 in the lateral region 15 shown by way of example in FIG. 2 and the micromechanical component 1 Is perpendicular to the depth of the lateral region 15 to the protrusion on the other surface 19 (that is, in the direction of taking the opening 11 and in the first cavity 5). These mechanical stresses (specifically, local mechanical stresses) are particularly present at and near the interface between the material area 13 of the cap 7 and the remaining area of the cap 7, which material area is converted into liquid accumulation in the third method step 103 After the third method step 103, it is converted into a solid aggregate and the access opening 11 is closed. The remaining area remains solid aggregate during the third method step 103. In FIG. 2 , the material area 13 of the closed access opening 11 of the cap 7 is only regarded as schematic, that is, it is represented schematically, especially in its lateral scale or shape (specifically parallel to another surface 19 extends the lateral dimension or shape), and especially in terms of the dimension or configuration it extends perpendicular to the lateral dimension (specifically perpendicular to the other surface 19).

Further, as in Figure 3 showing by way of example - in a fourth method step 104, the surface facing away from the substrate is formed with respect to the cap 3 or 7 of the first cavity 5 disposed in a region 1301 rises and the opening 11 of the acess The structure 1303 in order to provide the material region 13 of the substrate 3 or the cap 7 which is converted into a liquid aggregate in the third method step 103.

In FIG. 4 , or in FIG. 4A , the known micromechanical component 1 is represented by way of example. By way of example, here is shown a micromechanical assembly 1 with an integrated acceleration sensor and a rotation rate sensor hermetically closed with a cap wafer. In the second cavity 205 of the acceleration sensor, a higher internal pressure is adjusted during the capping process. By a known method, the lower internal pressure is adjusted in the first cavity 5 of the rotation rate sensor. If, for example, after the internal pressure in the first cavity 5 is adjusted, a crack is formed in the cap 7, the first cavity 5 of the rotation rate sensor becomes filled with, for example, air, and the rotation rate sensor may be Damped without oscillation and (for example) failed. Finally, the area of the opening 11 or the solidified material area 13 after being closed is shown in FIGS. 4B and 4C . In this case, FIGS. 4B and 4C show regions with higher mechanical stress or higher tensile stress.

FIGS. 5, 6, 7, 8 and 9 show schematic representations of the sub-regions of the known micromechanical component 1 according to FIG. 4 at different times in the known method.

In FIG. 6 , the absorption portion 21 or the region absorbing laser energy is shown by way of example, and at least part of it absorbs the laser radiation 211 schematically represented by an arrow. Laser radiation 211 or laser pulse 211 or a plurality of laser pulses 211 heat the material around the access hole 11 or around the opening 11 or use laser pulse 211 to surround the access hole 11 or around the opening 11 The material melts. In this case, the laser pulse 211 is preferably arranged centrally on the access hole 11 in order to form the smallest possible melting area and therefore use less laser power.

FIG. 7 shows the material region 13 in the form of liquid aggregates or in the form of molten metal 13. FIG. 7 shows the manner in which the molten material or molten material is distributed inside the molten region and closes the access hole 11 or the access opening 11. The melt or material region 13 subsequently solidifies.

In addition, FIG. 8 shows the time when the material region 13 has been partially converted from the liquid aggregate to the solid aggregate. Here, the portion of the material region 13 that has been converted into solid aggregates is indicated as a solidified front.

Finally, FIG. 9 shows by way of example that all material regions 13 have been converted into solid aggregates and after solidification, the raised portion 213 of the material region 13 protruding beyond the plane extending along the other surface 19 has been formed centrally above the access opening 11 the way. Here, the raised portion 213 is depicted as a conical protrusion portion having a height higher than that of the substrate by way of example.

By the method steps shown in FIGS. 5, 6, 7, 8 and 9 , for example, stress is induced in the cap material or in the cap 7 or in the substrate 3. These stresses or these stresses or these mechanical stresses occur especially during the solidification of the material region 13. For example, the strongest stress occurs at the lowest point of the molten region. Obviously, this can be explained, for example, by the fact that the melt is surrounded by the solid body to the greatest extent there, and therefore can respond the worst to different expansion movements. For example, the material can directly react with the protruding portion or the retracted portion on the surface. In the middle of the melting zone, this situation can be observed very clearly. For example, since the silicon from the edge begins to solidify and the expansion during setting, thus for example, a cone as indicated in FIG. 9 of the projecting portion in the middle region of the melt. The protruding portion is, for example, extremely high, so that it can extend a few microns above the substrate.

For example, there are four important points for the configuration shown in Figure 9:

-The area of the material with the greatest stress is just in and above the area of the access hole 11 or the access opening 11. The access hole 11 that is now closed or the access opening that is now closed is a disturbing portion in the bulk material. It therefore acts as a starting point for cracks, for example, and thus weakens the material.

-For example, a conical tip 213 is formed above the pick-up hole 11 or above the pick-up opening 11, which extends significantly beyond the base plate 3 or the cap 7. This is a risk for further processing and use in this field, and the tip can carry loads mechanically and thus create cracks in the material.

-The molten region or material region 13 or the absorption portion 21 converted into a liquid aggregate may vary with respect to the receiving hole 11 or with respect to the receiving opening 11 depending on the position of the laser. The disadvantage of this situation is that due to the asymmetric configuration of the molten region relative to the access hole, the asymmetric configuration can increase crack formation.

-Another disadvantage of the described changes in the fusion zone is that it is more difficult to perform automatic optical inspection. Especially when there are alignment structures or other auxiliary structures on the surface of the wafer, because the melting area changes relative to the auxiliary structure and therefore (for example) cannot be clearly distinguished from the defect in each case, automatic defect detection is more Difficult.

10, 11, 12, 13, 14, and 15 show schematic representations of sub-regions of the micromechanical component 1 according to an illustrative embodiment of the invention at different times in the method according to the invention . In this case, for example, it is specified that the substrate 3 or the cap 7 includes a structure 1303 that is raised relative to the surface 1301 of the substrate 3 or the cap 7 facing away from the first cavity 5 and is disposed in the area where the opening 11 is taken, so that A material area 13 of the base plate 3 or cap 7 is provided, which material area is converted into a liquid aggregate during the closing of the access opening 11.

Further, as in FIG. 14 and FIG. 15 showing by way of example, the structure 1303 by a predetermined material configured such that the region 103 after the third method step 13 is arranged substantially solidified in the cap or the substrate 3 facing away from the first 7 Between the plane 1305 on which the other surface 19 of the cavity 5 extends and the first cavity 5. Furthermore, as an alternative or in addition, the prescribed structure 1303 is configured such that the solidified material region 13 after the third method step 103 is arranged between the plane 1305 and another plane 1307 extending substantially along the surface 1301.

In addition, for example, the prescribed structure 1303 is configured such that the first area of the protrusion from the structure 1303 to the other plane 1307 is smaller than the second area of the protrusion from the solidified material region 13 to the other plane 1307 and/or is smaller than The third area of the absorption portion 21 of the substrate 3 or the cap 7 to the protrusion on the other plane 1307. This is shown in FIGS. 12, 13, 14, and 15 by way of example.

For example, FIG. 12 as indicated by way of example, the fourth predetermined area of the projecting portion 211 to the other of the laser radiation is substantially larger than the first area of the plane 1307 of the projection 1303 of the structure. This advantageously makes it possible for the absorption portion 21 of the substrate 3 or the cap 7 to be geometrically divided into absorbing the first sub-component and absorbing the second sub-component, so that the first sub-component is arranged inside the structure 1303 and the second sub-component is arranged at In the area of the surface 1301 of the substrate or the cap. In other words, due to the selected configuration or selected geometry of the structure 1303, laser energy is absorbed in two different regions on the substrate. In this case, for example, it is provided that most energy is absorbed in the upper region of the elevated portion or in the upper region of the structure 1303. For example, in the substrate 3 or cap 7 whose level is lower than the reference point of the elevated portion or structure 1303, or in the area of the surface 1301 in the ring around the elevated portion or structure 1303, a small portion of the laser is absorbed energy. In this case, for example, it is prescribed that the energy of the coupling may only be dissipated in the upper region of the elevated portion or in the structure 1303 in the downward direction or in the direction toward the first cavity 5. In this case, the material of the substrate 3 or the cap 7 containing (for example) silicon melts in the upper region of the structure 1303 or in the first sub-portion, and due to the surface energy of the material region 13 forms a nearly spherical melting region or almost Spherical material area 13, so the contour of this material area is determined by the geometry of the elevated portion. After the material area 13 has been converted into a liquid aggregate, the melt or material area 13 solidifies and closes the access hole or access opening 11. By way of example, it is also provided that very little laser energy is absorbed in the lower region around the elevated portion or in the second sub-portion. The energy absorbed in the second sub-portion can, for example, dissipate in almost all directions. Thus, for example, it is provided that only fewer areas melt, or that the second sub-portion contains fewer material areas 13 than the first sub-portion. For example, it is provided that the material region 13 of the second sub-portion solidifies again very quickly, or melting does not occur at all, that is, the second sub-portion does not contain the material area 13.

In FIGS. 13 and 14 , the structure 1303 shown in FIGS. 10, 11, 12 and 13 is configured by way of example so that the material region 13 is geometrically self-limiting with liquid aggregates.

Furthermore, for example, it is also provided that the structure 1303 is substantially rotationally symmetrical and/or circular with respect to the access opening 11 and/or with respect to the center of mass of the solidified material region 13 and/or with respect to the absorption portion 21 of the substrate 3 or cap 7 It is configured in another plane 1307 like this.

For example, the prescribed structure 1303 is formed by etching a partial ring in the substrate 3 or the cap. This is shown in FIG. 12 by way of example. Alternatively or additionally, it is also provided that the structure 1303 is formed by applying the first substrate portion of the substrate 3 or the first cap portion of the cap 7 to the second substrate portion of the substrate 3 or the second cap portion of the cap 7. According to the present invention, for example, a plurality of deposition processes and/or growth processes and/or construction processes are provided to form the structure 1303.

Finally, for example, the maximum dimension 1309 of the structure 1303 in the third plane 1311 extending substantially parallel to the surface 1301 is substantially separated from the point 1313 in the access channel 11 in the third plane 1311 as the third plane 1311 The maximum dimension 1315 of the access channel 11 and the midpoint 1313 in the separated configuration is at most six times or at most five times or at most four times or at most three times or at most twice. This is shown in FIG. 11 by way of example. For example, as an alternative or in addition, the central diameter of the raised portion or structure 1303 is also configured to be configured at a ratio lower than 5:1 compared to the central diameter of the access hole or access opening 11. This situation advantageously achieves the effect that after the melting and solidification process, the highest point of the raised portion or material region 13 is below the level of the substrate surface, or does not protrude beyond the other surface 19, and is therefore or In a mechanically protected area.

Compared with the prior art, the method according to the invention and other advantages of the micromechanical component according to the invention are:

-The solidified material or the solidified material region 13 is arranged above the surface 1301 or placed on the elevated portion, that is, in the form of a cylinder. In this case, the thermal stress during the cooling process can be well reduced, and a very stable configuration in terms of internal stress can be obtained. For example, this is due to the fact that when the mechanical stress occurring in the area of the closed access opening 11 can be relieved by the elastic deformation of the remaining part of the structure 1303 when the access opening 11 is closed, or Transfer to a region of the substrate 3 or the cap 7 further away from the access opening 11.

-No conical tip or only a small conical tip is formed above the access hole or access opening 11 end. First, form a spherical surface. Depending on the configuration, it is additionally possible to achieve the following effect: the highest point of the spherical surface is below the surface of the substrate, or is disposed below the other surface 19, and is therefore in the mechanical protection area.

-The melting area or material area 13 is defined by the configuration of the raised portion. The system does not respond to minor positioning inaccuracies of the laser, or responds less than is known from prior art. A more stable system and simpler automatic defect detection become possible.

1‧‧‧Micromechanical components

3‧‧‧ substrate

5‧‧‧ First cavity

7‧‧‧block

9‧‧‧Environment

11‧‧‧Access opening/access hole

Claims (10)

A method for manufacturing a micromechanical component (1) having a substrate (3) and a cap (7), which is connected to the substrate (3) and surrounds the substrate (3) A first cavity (5) is sealed, a first pressure exists in the first cavity (5), and a first gas mixture having a first chemical composition is enclosed in the first cavity (5) In a first method step (101), an access opening (11) is formed in the substrate (3) or the cap (7), which connects the first cavity (5) to the micro An environment (9) of the mechanical component (1), in a second method step (102), the first pressure and/or the first chemical composition in the first cavity (5) are adjusted in a first In the three method step (103), a laser is used to introduce energy or heat into an absorption portion (21) of the substrate (3) or the cap (7) to close the access opening (11), characterized in that : In a fourth method step (104), a structure (1303) is formed which is opposite to a surface (1301) of the first cavity (5) opposite to the back of the substrate (3) or the cap (7) ) Raised and arranged in the area of the access opening (11) in order to provide a material area (13) of the substrate (3) or the cap (7), the material area in the third method step (103) Converted into a liquid aggregate. A method as claimed in item 1 of the patent application, wherein the cap (7) and the substrate (3) enclose a second cavity, a second pressure exists in the second cavity, and has a second chemical composition A second gas mixture is enclosed in the second cavity. For example, the method of applying for the first or second item of patent scope, in which the structure (1303) is configured, In this way, the material region (13) solidified after the third method step (103) is arranged between a plane (1305) and the first cavity (5), the plane (1305) substantially along the substrate ( 3) Or the back of the cap (7) extends to another surface (19) of one of the first cavities (5). For example, the method of claim 1 or item 2, wherein the structure (1303) is configured so that the solidified material region (13) after the third method step (103) is arranged on a plane ( 1305) and another plane (1307), the plane (1305) is substantially along the other surface (19) of the first cavity (5) along the back of the base plate (3) or the cap (7) ) Extends, the other plane (1307) extends substantially along the surface (1301). For example, the method of claim 1 or item 2, wherein the structure (1303) is configured such that the structure (1303) is projected to another plane (1307) that extends substantially along the surface (1301) The first area on the top is smaller than the second area of the solidified material area (13) projected onto the other plane (1307), and/or smaller than the absorbing portion of the substrate (3) or the cap (7) (21) A third area projected onto the other plane (1307). For example, the method of claim 1 or claim 2, wherein the structure (1303) is substantially relative to the access opening (11) and/or relative to the center of mass of the solidified material region (13), and /Or the absorption portion (21) of the substrate (3) or the cap (7) is rotationally symmetrical and/or annularly arranged in another plane extending substantially parallel to the surface (1301) (1307). A method as claimed in item 1 or item 2 of the patent scope, wherein the structure (1303) in a third plane (1311) extending substantially parallel to the surface (1301) is substantially in line with the third plane (1311) The middle point (1313) of the access channel (11) is separated A maximum scale (1309) is at most six times, or at most five times, the maximum scale (1315) of one of the largest scales (1315) separated by the access channel (11) and the midpoint (1313) in the third plane (1311), Or at most four times, or at most three times, or at most two times. A micromechanical component (1) having a substrate (3) and a cap (7) connected to the substrate (3) and enclosing a first cavity (5) with the substrate (3) , A first pressure exists in the first cavity (5) and a first gas mixture with a first chemical composition is enclosed in the first cavity (5), the substrate (3) or the cap (7) includes a closed access opening (11), characterized in that the substrate (3) or the cap (7) includes a structure (1303), which is opposite to the substrate (3) or the cap (7) A surface (1301) of the first cavity (5) is raised and arranged in the area of the access opening (11) to provide a material area of the substrate (3) or the cap (7) (13), the material area is converted into a liquid aggregate during the closing of the access opening (11). For example, the micromechanical component (1) of claim 8 of the patent application, wherein the cap (7) and the substrate (3) enclose a second cavity, and a second pressure exists in the second cavity and has A second gas mixture of a second chemical component is enclosed in the second cavity. For example, the micromechanical component (1) of claim 8 or item 9, wherein the first pressure is lower than the second pressure, and a first sensor unit for rotation rate measurement is disposed on the first In a cavity (5), a second sensor unit for acceleration measurement is disposed in the second cavity.

Images