MEMS resonator integrated cicruit fabrication

A method of fabricating an oscillator integrated circuit device, the method comprising:

• providing a lead frame having an electrical lead with internal and external electrical contact surfaces at respective first and second heights within a cross-sectional profile of the oscillator integrated circuit device, and a die-mounting surface at an intermediate height between the first and second heights;
• mounting a control die to the die-mounting surface, such that at least a portion of the control die is disposed between the first and second heights within the cross-sectional profile of the oscillator integrated circuit device;
• wire-bonding the control die to the internal electrical contact surface;
• mounting a MEMS resonator die in a stacked configuration with the control die;
• electrically coupling the MEMS resonator die with the control die;
• and
• encapsulating the MEMS resonator die, at least one surface of the control die, the internal electrical contact surface, and the die-mounting surface within a package enclosure of the oscillator integrated circuit device, in a manner such that the external electrical contact surface is exposed at an external surface oscillator integrated circuit device.

A method of fabricating an oscillator integrated circuit device having a control die and a MEMS resonator die, wherein the MEMS resonator die comprises a MEMS resonant structure and where in the control die comprises CMOS circuitry, the method comprising:

• affixing the control die to a die-mounting structure;
• wire-bonding electrically-conductive leads to the control die;
• stacking the MEMS resonator die with the control die, and electrically coupling the MEMS die resonator die with the control die;
• and
• enveloping the MEMS resonator die, the control die and wire-bonding within a package enclosure of the oscillator integrated circuit device, such that electrical contacts coupled to the control die, via the electrically conductive leads, are exposed at an external surface of the oscillator integrated circuit device.