The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 16, 2003
Filed:
Jan. 09, 2001
Thomas Laurell, SE-224 73 Lund, SE;
Johan Drott, SE-222 20 Lund, SE;
Johan Nilsson, SE-237 35 Bjarred, SE;
Lars Wallman, SE-270 33 Vollsjo, SE;
Other;
Abstract
The invention relates to a method for etching an opening, and more precisely, to etching in a silicon plate for creating a nozzle opening. According to the invention, one side of the silicon plate ( ) is protected by a protective layer ( ), and a recess ( ) is made in the protective layer. Etching is made anisotropically through the recess so as to create a cavity ( ) in the shape of a truncated pyramid of a predetermined depth in the silicon plate. The cavity is doped so as to create a doped layer ( ) at the predetermined depth. The etching is then continued until the bottom surface of the cavity has passed the doped layer. Subsequently, etching is performed from the other side, while a voltage is applied to the doped layer, so as to free the nozzle opening at the other side. The invention enables an accurate control of the surface area of the nozzle opening. Through this, the amount of discharged fluid and the directional precision can be controlled very accurately.