An apparatus for fabricating an ultrasound transducer assembly comprising: a bottom plate that includes a first cavity, wherein the first cavity includes a first pocket configured to accommodate a Piezoelectric Micromachined Ultrasound Transducer (PMUT) die and a second pocket configured to accommodate an Application Specific Integrated Circuit (ASIC) die; a bonding plate configured to be positioned over and against the bottom plate, the bonding plate including a recess, wherein when the bonding plate is positioned against the bottom plate: the PMUT die and the ASIC die are trapped in a fixed position; and the recess exposes a portion of the first pocket and a portion of the second pocket; a molding plate configured to be positioned over and against the bottom plate, wherein the molding plate includes: a second cavity that is aligned with the first cavity when the molding plate is positioned against the bottom plate, such that the first and second cavities collectively define a shape of a transducer assembly; a first opening that is coupled to the second cavity, wherein the first opening exposes a portion of the first pocket when the molding plate is positioned against the bottom plate; a second opening that is coupled to the second cavity, wherein the second opening exposes a portion of the second pocket when the molding plate is positioned against the bottom plate; and a third opening that is in fluid communication with the first and second cavities such that a fluid can flow into the first and second cavities through the third opening; and characterised in that the apparatus further comprises a first shut-off pin configured to be positioned inside the first opening of the molding plate such that, when the molding plate is positioned against the bottom plate, the first shut-off pin makes physical contact with an upper surface of the PMUT die. a bottom plate that includes a first cavity, wherein the first cavity includes a first pocket configured to accommodate a Piezoelectric Micromachined Ultrasound Transducer (PMUT) die and a second pocket configured to accommodate an Application Specific Integrated Circuit (ASIC) die; a bonding plate configured to be positioned over and against the bottom plate, the bonding plate including a recess, wherein when the bonding plate is positioned against the bottom plate: the PMUT die and the ASIC die are trapped in a fixed position; and the recess exposes a portion of the first pocket and a portion of the second pocket; the PMUT die and the ASIC die are trapped in a fixed position; and the recess exposes a portion of the first pocket and a portion of the second pocket; a molding plate configured to be positioned over and against the bottom plate, wherein the molding plate includes: a second cavity that is aligned with the first cavity when the molding plate is positioned against the bottom plate, such that the first and second cavities collectively define a shape of a transducer assembly; a first opening that is coupled to the second cavity, wherein the first opening exposes a portion of the first pocket when the molding plate is positioned against the bottom plate; a second opening that is coupled to the second cavity, wherein the second opening exposes a portion of the second pocket when the molding plate is positioned against the bottom plate; and a third opening that is in fluid communication with the first and second cavities such that a fluid can flow into the first and second cavities through the third opening; and characterised in that the apparatus further comprises a first shut-off pin configured to be positioned inside the first opening of the molding plate such that, when the molding plate is positioned against the bottom plate, the first shut-off pin makes physical contact with an upper surface of the PMUT die. a second cavity that is aligned with the first cavity when the molding plate is positioned against the bottom plate, such that the first and second cavities collectively define a shape of a transducer assembly; a first opening that is coupled to the second cavity, wherein the first opening exposes a portion of the first pocket when the molding plate is positioned against the bottom plate; a second opening that is coupled to the second cavity, wherein the second opening exposes a portion of the second pocket when the molding plate is positioned against the bottom plate; and a third opening that is in fluid communication with the first and second cavities such that a fluid can flow into the first and second cavities through the third opening; and characterised in that the apparatus further comprises a first shut-off pin configured to be positioned inside the first opening of the molding plate such that, when the molding plate is positioned against the bottom plate, the first shut-off pin makes physical contact with an upper surface of the PMUT die.