Abstract: An insulating layer with at least one via is provided over a metal plate. A sacrificial layer is applied over a portion of the insulating layer so that the sacrificial layer extends into the via. A metal bridge having at least one opening is provided over a portion of the sacrificial layer and a portion of the insulating layer so that the metal bridge extends over the via and the opening is situated adjacent a portion of the sacrificial layer. A reinforcing seal layer with a well is provided over the metal bridge so that the well is situated adjacent to at least a portion of the opening. The sacrificial layer is then removed.

Abstract: An improved method for the recovery of stevioside from Stevia rebaudiana Bertoni plants is provided which does not require the use of dangerous chemicals or special separation equipment such as ion exchange or chromatography. In the process the raw material, preferably in comminuted form is first extracted with water, the resulting aqueous extract is treated with a di- or tricarboxylic acid chelating agent to remove metallic and other impurities as well as to lower the pH to less than about 4. Subsequently a calcium-containing agent is added to precipitate out other impurities. The aqueous extract is essentially neutralized with an acid and is then subject to extraction with a water-immiscible solvent. Purified stevioside crystals are recovered by cooling the water layer obtained from said solvent extraction step.