Abstract: The present invention relates to a method for making a package structure having recession portion on the surface thereof. The method comprises: (a) providing a lead frame having a plurality of package units, each package unit having a plurality of leads and a die paddle; (b) providing an upper mold and a lower mold for clamping the lead frame, wherein the upper mold and the protruding block of the lower mold clamp the first portions of the leads so as to prevent molding compound bleeding to the upper surfaces of the first portions during mold filling operation, for improving the product yield; (c) injecting a molding compound between the upper mold and the lower mold, and forming a plurality of accommodation spaces; (d) attaching a plurality of chips onto the die paddles; (e) electrically connecting the chips to the first portions of the leads; (f) sealing the accommodation spaces; and (g) segregating the package units.

Abstract: The invention provides a variable focus liquid lens using electrowetting, comprising a conductive first liquid and an insulating second liquid. At least one of the first liquid composed of electrolyte and the second liquid composed of insulating liquid contains a surfactant for reducing interfacial energy between the first and second liquids. An interfacial portion between the first and second liquids is gathered by surfactant to reduce driving voltage. The variable focus liquid lens according to the invention has about 50% lower driving voltage required for changing focus, ensuring stability of the two fluids.