PRESSURE SENSOR, ESPECIALLY PRESSURE DIFFERENCE SENSOR

1 - 12 . (canceled)

13 . A pressure sensor, comprising:

at least one platform;

at least one measuring membrane; and

a transducer, wherein:

said at least one measuring membrane comprises a semiconductor material, encloses a pressure chamber, is secured on said at least one platform, is contactable with at least one pressure, and is elastically deformable in a pressure-dependent manner;

said transducer provides an electrical signal dependent on deformation of said at least one measuring membrane;

said at least one platform has a membrane bed, on which said at least one measuring membrane lies in the case of overload, in order to support said at least one measuring membrane;

said membrane bed has a glass layer, whose surface faces said at least one measuring membrane and forms a wall of said pressure chamber;

said surface of said glass layer has a contour, which is suitable for supporting said at least one measuring membrane in the case of overload; and

said contour of said membrane bed is obtainable by a sagging of an unsupported region of a glass plate at increased temperature, due to the force of gravity on the unsupported region of said glass plate, and subsequent cooling of said glass plate.

14 . The pressure sensor as claimed in claim 13 , wherein:

said at least one platform comprises a substrate, which has a surface facing said glass layer, which supports said glass layer; and

said surface has a cavity, via which the contour of said membrane bed is formed.

15 . The pressure sensor as claimed in claim 13 , wherein:

said cavities are filled on the rear side with a fill material, in order to prevent hollow spaces under said glass layer.

16 . The pressure sensor as claimed in claim 15 , wherein:

the fill material especially comprises a glass, which has a lower melting temperature than the glass of said glass layer.

17 . The pressure sensor as claimed in claim 13 , wherein:

said glass layer has a thickness of not less than 100 μm, preferably not less than 200 μm and further preferably not less than 400 μm.

18 . The pressure sensor as claimed in claim 13 , wherein:

said glass layer has a thickness of no more than 2000 μm, preferably no more than 1400 μm and further preferably no more than 1000 μm.

19 . The pressure sensor as claimed in claim 13 , wherein:

said membrane bed has an aspherical surface contour, especially approximately the deflection curve of said at least one measuring membrane, or equal thereto.

20 . A method for the preparation of a membrane bed of a pressure sensor, comprising the steps of:

(a) providing a planar glass layer;

(b) applying the glass layer on a support body, which has a surface, which supports the glass layer, wherein the surface has at least one cavity, so that the glass layer is not supported in the region of the cavity;

(c) heating the glass layer to a temperature or temperature range, at which the unsupported region of the glass layer sinks; and

(d) allowing the glass layer to cool.

21 . The method as claimed in claim 20 , wherein:

the glass layer, after reaching a temperature, at which the unsupported region sinks, is held for a holding time at such temperature, so that the glass layer can sink to a sufficient extent.

22 . The method as claimed in claim 21 , wherein:

the holding time for a borosilicate glass is given by the relationship t=a*d+b;

the value for a at 750° C. lies between 0.1 and 0.8, especially between 0.2 and 0.6, and the value for b lies between −60 and 20, especially between −40 and 0, wherein t is the time in minutes and d the thickness of the glass layer in μm.

23 . The method as claimed in claim 20 , wherein:

the preparation of the membrane bed contour occurs on one undivided wafer for a plurality of membrane beds.

24 . A method for manufacturing a pressure sensor, comprising:

preparing a membrane bed according to the method as claimed in claim 20 , and joining a measuring membrane with the platform, or the glass layer of the platform, which forms the membrane bed.