Leadframe-based premolded package having air channel for microelectromechanical system (MEMS) device

摘要

A low-cost microelectromechanical system (MEMS) device has a mass-produced carrier fabricated as a pre-molded leadframe so that the space of the leadframe center is filled with compound and a two-tier stepped recess is created in the center. The first tier is filled by an inset with a first perforation and a second perforation. An integrated circuit chip with an opening and a membrane at the end of the opening, operable as a pressure sensor, microphone, speaker, etc, is assembled on the inset so that the chip opening is aligned with the first perforation. The chip is protected by a cover transected by a vent aligned with the second inset perforation. An air channel extends from the ambient exterior through the vent and the second perforation to the second tier recess, which acts as a channel and connects to the first perforation and the chip opening to the membrane.

主权项

1. A method for fabricating a micro electromechanical system (MEMS) device, comprising:
providing a leadframe having a plurality of leads surrounding a central open space, the leads made from a metal sheet having a height; filling the open space with a polymeric compound, thereby embedding the leads and forming a carrier having the height and a surface; forming a recess in the open space; attaching an inset having a first perforation and a second perforation; attaching an integrated circuit chip having an opening extending through the chip, the opening capped by a foil at a circuit side and unobstructed at a opposite side, onto the inset so that the opening is in communication with the first perforation; and attaching a cover onto the surface of the carrier to enclose the chip.