Claims for Patent: 7,896,264

Summary for Patent: 7,896,264

Title:	Microstructured high pressure nozzle with built-in filter function
Abstract:	A microstructured nozzle consists of a number of channels produced by microstructuring a plate-shaped member. In the nozzle the channels are located between projections which are arranged side by side in rows and project from a base plate. This microstructured base plate is covered with a cover plate. The channels are narrowly defined in terms of shape, cross sectional area and length. The nozzle contains a filter as the primary structure and a secondary structure downstream of the filter. The nozzle is used, for example, with an atomiser which produces an aerosol from a fluid containing a medicament.
Inventor(s):	Eicher; Joachim (Dortmund, DE), Geser; Johannes (Ingelheim, DE), Hausmann; Matthias (Dortmund, DE), Reinecke; Holger (Dortmund, DE)
Assignee:	Boehringer Ingelheim International GmbH (Ingelheim am Rhein, DE)
Application Number:	10/877,134
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 7,896,264
Patent Claims:	1. Microstructured nozzle comprising: an inlet for unfiltered fluid, an outlet for filtered fluid defining a flow direction, a main filter between the inlet and outlet, the main filter comprising a plurality of zigzag projections extending transversely to the flow direction from a base plate, defining a plurality of channels and forming spikes in directions of the inlet and the outlet, and a filtrate collecting chamber between the main filter and the outlet, the filtrate collecting chamber comprising a plurality of pillar-shaped built-in elements extending from the base plate transversely to the flow direction covering an area between the outlet and the main filter and at least part of an area extending between the zigzag projections directed towards the outlet, wherein one or more spacings between the built-in elements, each of which forms a throughflow channel for the liquid passing through, are such that a resulting cross sectional area transverse to the direction of flow which is effectively permeable to the liquid is greater than a corresponding effective cross sectional surface area of the throughflow channels formed by the projections of the main filter such that the built-in elements do not substantially increase a flow resistance. 2. Microstructured nozzle according to claim 1, wherein the built-in elements have a cylindrical circumferential wall. 3. Microstructured nozzle according to claim 1, wherein the built-in elements are at a spacing of from 0.005 mm to 0.02 mm from one another. 4. Microstructured nozzle according to claim 1, wherein the built-in elements have a diameter of from 0.005 mm to 0.02 mm. 5. Microstructured nozzle according to claim 1, wherein the built-in elements have a concave circumferential wall. 6. Microstructured nozzle according to claim 1, wherein the built-in elements have a convex circumferential wall. 7. Microstructured nozzle according to claim 1, wherein the pillar-shaped built-in elements extend from the base plate to a cover plate. 8. Microstructured nozzle according to claim 1, wherein the projections are formed defining an inlet side of the zigzag configuration between the inlet and the projections, an outlet side of the zigzag configuration between the projections and the outlet, and a central line of the zigzag configuration. 9. Microstructured nozzle according to claim 1, wherein the projections are arranged side by side over an entire width of the filter. 10. Microstructured nozzle according to claim 8, wherein the built-in elements are formed as an integral part of the base plate on the side of the outlet of the zigzag configuration up to the central line. 11. Microstructured nozzle according to claim 8, wherein the built-in elements are formed right into the spikes projecting in the direction of the inlet. 12. Microstructured nozzle according to claim 8, wherein the built-in elements are formed in front of and behind the zigzag configuration in the direction of flow. 13. Microstructured nozzle according to claim 1, wherein a spacing between the base plate in an area around the projections and a cover plate within a row of projections is about the same size as a width of the channels on a side of the projections where the fluid enters the row of projections defining channels. 14. Microstructured nozzle according to claim 1, wherein the plurality of projections are in the form of columns with a round shape, wherein several rows of the projections are arranged in a zigzag shaped arrangement, a cross section of the channels decreases from row to row perpendicularly to the direction of flow of the fluid, viewed in the direction of flow, the projections that are closer to a side of the inlet of the main filter are larger or are more numerous, so that the channels between them are smaller than the channels between the projections arranged more on a side of the outlet of the filter, a spacing between the base plate and a cover plate in an area around each row of projections is about a same size as a width of the channels on the side of the inlet where the fluid enters, an oblong inlet slot for the unfiltered fluid extends over approximately an entire width of the main filter and is about a same height as the projections protruding from the base plate on the inlet side of the main filter, and an oblong outlet slot for the filtered fluid extends over approximately the entire width of the filter and is about a same height as the projections protruding from the base plate on the outlet side of the filter. 15. Microstructured nozzle according to claim 1, wherein all the projections of the main filter and the built-in elements are formed on the base plate. 16. Microstructured nozzle according to claim 1, wherein the base plate is flat, a spacing between the flat base plate in an area around the projections and a flat cover plate within a row of projections is between half and twice a width of the channels on a side of the projections where the fluid enters the row of projections defining channels. 17. Microstructured nozzle according to claim 1, wherein facing sides of two adjacent rows of projections define a cohesive chamber into which the fluid from all the channels flows between the projections of a first row and out of which the fluid flows into all the channels between the projections of a next row in the direction of flow. 18. Microstructured nozzle according to claim 1, wherein the collecting chamber has an oblong cross section between an inlet slot and a first row of projections into which the unfiltered fluid is conveyed and out of which the fluid flows into all the channels between the projections of the first row, and the collecting chamber has an oblong cross section between a last row of projections and an outlet slot into which the fluid from all the channels of the last row flows, and out of which the filtered fluid is discharged. 19. Microstructured nozzle according to claim 1, wherein the projections are in a form of posts which are straight or curved, viewed in the direction of flow, or the projections are in a form of columns. 20. Microstructured nozzle according to claim 1, wherein the channels are at least twice a height of the channels at the entry side for the fluid, a cross section of the channels remaining constant. 21. Microstructured nozzle according to claim 1, wherein the channels have a length of 5 .mu.m to 50 .mu.m, and a height of 2.5 to 25 .mu.m. 22. Microstructured nozzle according to claim 1, wherein the channels are barrel-shaped or trapezoidal in cross section. 23. Microstructured nozzle according to claim 1, wherein the channels are of approximately square cross section on a side of the fluid inlet and the cross section becomes wider towards a side of the fluid outlet. 24. Microstructured nozzle according to claim 1, wherein the rows of projections are space apart a distance that is twice a size of a width of the channel on a side of the inlet. 25. Microstructured nozzle according to claim 8, wherein rows in the zigzag configuration are inclined towards one another at an angle .alpha. of 2.degree. to 25.degree.. 26. Microstructured nozzle according to claim 1, characterised by a constant spacing between the base plate, which is flat, in an area around the projections and a flat cover plate within a row of projections. 27. Microstructured nozzle according to claim 1, characterised by a spacing between the base plate and a cover plate which tapers in the direction of flow. 28. Microstructured nozzle according to claim 8, characterised by a spacing between the base plate, which is flat, in an area around the projections and a flat cover plate within a row of projections arranged in the zigzag configuration that increases from a region of an end of a row located close to the inlet side of the filter towards a region of an end of a row located close to the outlet side of the filter. 29. Microstructured nozzle according to claim 1, wherein the base plate is structured by isotropic or anisotropic wet or dry etching or a combination of these methods, preferably by anisotropic dry etching. 30. Microstructured nozzle according to claim 1, wherein the base plate is made of silicon, and the nozzle further comprises a cover plate made of glass, attached by anodic bonding. 31. Microstructured nozzle according to claim 1, wherein the filtrate collecting chamber tapers conically in the direction of flow and has at least one nozzle as the outlet. 32. Microstructured nozzle according to claim 1, wherein the base plate is made of silicon, and the nozzle further comprises a cover plate made of silicon, attached by direct bonding. 33. Microstructured nozzle according to claim 1, wherein spacings between the built-in elements, each of which forms a throughflow channel for the liquid passing through, are such that a resulting cross sectional area perpendicular to the direction of flow which is effectively permeable to the liquid is greater than a corresponding effective cross sectional surface area of the throughflow channels formed by the projections of the main filter. 34. Atomiser for inhalation therapy which comprises a microstructured filter according to claim 1. 35. Process for producing a nozzle according to claim 1, wherein in one step microstructures in a form of the filter projections, built-in elements, nozzle inlet and nozzle outlet are etched into one side of a silicon wafer for a large number of nozzles, in a subsequent step a glass plate is firmly attached to this side of the silicon wafer, in an independent step the silicon wafer is placed on an adhesive film and in a final step the individual nozzles are produced from an assembly comprising the silicon wafer and glass plate with the adhesive film on an underside of the silicon wafer, starting from the glass plate side, using a diamond saw. 36. Microstructured nozzle according to claim 1, wherein at least some built-in elements form equilateral hexagonal designs, wherein a center of each of the hexagonal designs is formed by a built-in element and each angle of each of the hexagonal designs is formed by adjacent built-in elements. 37. Microstructured nozzle according to claim 1, wherein the built-in elements are 200000 to 300000 per square centimeter.