Microcap packaging of micromachined acoustic devices
Transducer structures and methods of manufacture are described.
1 . A transducer structure, comprising:
a substrate having an upper surface and a lower surface;
a transducer disposed over the upper surface and over a cavity in the substrate;
a microcap structure having a gasket, which contacts the upper surface of the substrate; and
an opening adapted to provide ambient pressure equalization, or directional acoustic reception or transmission to the transducer.
2 . A transducer structure as claimed in claim 1 , further comprising a component disposed over the substrate, wherein the component includes electrical circuitry.
3 . A transducer structure as claimed in claim 1 , wherein the opening is provided through the microcap.
4 . A transducer structure as claimed in claim 1 , wherein the opening is provided through the gasket.
5 . A transducer structure as claimed in claim 1 , wherein the opening is provided in the transducer.
6 . A transducer structure as claimed in claim 1 , further comprising a via adapted to provide electrical connectivity to the transducer structure.
7 . A transducer structure as claimed in claim 6 , wherein the via is disposed in the microcap.
8 . A transducer structure as claimed in claim 6 , wherein the via is disposed in the substrate.
9 . A transducer structure as claimed in claim 1 , wherein the microcap further comprises electrical circuitry.
10 . A transducer structure as claimed in claim 6 , wherein the structure is flip-chip mounted over another substrate.
11 . A transducer structure as claimed in claim 1 , wherein the transducer is a microphone.
12 . A transducer structure as claimed in claim 3 , wherein the opening is offset relative to the transducer.
13 . A transducer structure as claimed in claim 1 , wherein the transducer is a piezoelectric transducer.
14 . A transducer structure as claimed in claim 1 , wherein the transducer is a capacitive transducer.
15 . A method of fabricating a transducer, the method comprising:
providing a substrate;
etching a cavity in the substrate;
disposing a transducer over the cavity;
providing a microcap over the substrate; and
forming an opening adapted to provide ambient pressure equalization, or directional acoustic reception or transmission to the transducer.
16 . A method as claimed in claim 15 , wherein the forming the opening further comprises etching the microcap.
17 . A method as claimed in claim 15 , wherein the forming the opening further comprises forming the opening in a gasket in the microcap.
18 . A method as claimed in claim 15 , wherein the forming the opening further comprises forming an opening in the transducer.
19 . A method as claimed in claim 15 , further comprising:
forming vias in the microcap, wherein the vias are electrically connected to contact pads disposed over an upper surface of the substrate.
20 . A method as claimed in claim 15 , wherein the microcap further comprises electrical circuitry.
21 . A method as claimed in claim 19 , further comprising flip-chip bonding the microcap to another substrate.