Techniques are described herein that perform pressure sensing using pressure sensor(s) that include deformable pressure vessel(s). A pressure vessel is an object that has a cross section that defines a void. A deformable pressure vessel is a pressure vessel that has at least one curved portion that is configured to structurally deform (e.g., bend, shear, elongate, etc.) based on a pressure difference between a cavity pressure in a cavity in which at least a portion of the pressure vessel is suspended and a vessel pressure in the pressure vessel.

An example method of producing a microelectromechanical system (MEMS) package, the method comprising: applying first epoxy layers to a first substrate, at least one of the first epoxy layers coupled to a second substrate; applying a first post gel heat treatment to the first epoxy layers; after applying the first post gel heat treatment to the first epoxy layers, applying second epoxy layers to the second substrate and to the first epoxy layers; and applying a second post gel heat treatment to the first epoxy layers and the second epoxy layers.

A piezoelectric microelectromechanical systems diaphragm microphone can be mounted on a printed circuit board. The microphone can include a substrate with an opening between a bottom end of the substrate and a top end of the substrate. The microphone can have two or more piezoelectric film layers disposed over the top end of the substrate and defining a diaphragm structure. Each of the two or more piezoelectric film layers can have a predefined residual stress that substantially cancel each other out so that the diaphragm structure is substantially flat with substantially zero residual stress. The microphone can include one or more electrodes disposed over the diaphragm structure. The diaphragm structure is configured to deflect when the diaphragm is subjected to sound pressure via the opening in the substrate.

An example method of producing a microelectromechanical system (MEMS) package, the method comprising: applying first epoxy layers to a first substrate, at least one of the first epoxy layers coupled to a second substrate; applying a first post gel heat treatment to the first epoxy layers; after applying the first post gel heat treatment to the first epoxy layers, applying second epoxy layers to the second substrate and to the first epoxy layers; and applying a second post gel heat treatment to the first epoxy layers and the second epoxy layers.