Package-integrated piezoelectric device for blood-pressure monitoring using wearable package systems

A method of forming a piezoelectric sensor in a wearable device, comprising:

• forming a first electrode on a carrier substrate;
• forming a piezoelectric layer on the first electrode;
• forming a second electrode over the piezoelectric layer;
• forming a stretchable substrate over the carrier substrate, wherein the stretchable substrate encases the first electrode, the piezoelectric layer, and the second electrode;
• and
• removing the stretchable substrate from the carrier substrate.

A wearable blood-pressure monitor, comprising:

• a stretchable substrate;
• a semiconductor die embedded in the stretchable substrate;
• an electrocardiogram sensor electrically coupled to the semiconductor die;
• and
• a ballistocardiograph sensor embedded within the stretchable substrate and electrically coupled to the semiconductor die, wherein the ballistocardiograph sensor is a piezoelectric sensor that comprises:
• a piezoelectric layer;
• a first electrode formed in contact with a first surface of the piezoelectric layer;
• and
• a second electrode formed in contact with a second surface of the piezoelectric layer that is opposite to the first surface.