Electronic package including cavity formed by removal of sacrificial material from within a cap
An electronic component comprises a substrate including a main surface on which a functional unit is formed and a cap layer defining a cavity enclosing and covering the functional unit. The cap layer is provided with holes communicating an inside of the cavity with an outside of the cavity. A resin layer covers the cap layer and the main surface and includes one or more bores and a solder layer having a thickness less than a thickness of the resin layer disposed within the one or more bores.
1. An electronic component comprising:
a substrate including a main surface on which a functional unit is formed;
a cap layer defining a cavity enclosing and covering the functional unit, the cap layer being provided with holes communicating an inside of the cavity with an outside of the cavity; and
a resin layer covering the cap layer and the main surface, the resin layer including one or more bores and a solder layer having a thickness less than a thickness of the resin layer disposed within the one or more bores.
2. The electronic component of claim 1 wherein the cap layer includes a rectangular periphery, the holes being formed at each one of four corners of the rectangular periphery.
3. The electronic component of claim 2 wherein edges of each hole are defined by both the cap layer and the main surface of the substrate.
4. The electronic component of claim 1 wherein the cap layer includes silicon dioxide containing carbon.
5. The electronic component of claim 4 wherein a linear expansion coefficient of the cap layer is substantially the same as a linear expansion coefficient of the resin layer.
6. The electronic component of claim 1 wherein a gap is defined between a periphery of the solder layer and a peripheral surface defined by a corresponding bore.
7. The electronic component of claim 1 wherein the functional unit is one of a surface acoustic wave element or a film bulk acoustic resonator including a mechanically movable portion.
8. The electronic component of claim 1 wherein the substrate includes a dielectric material.
9. The electronic component of claim 8 wherein the substrate includes a piezoelectric dielectric material.
10. The electronic component of claim 1 wherein the holes are defined in a ceiling of the cap layer.
11. The electronic component of claim 1 wherein the cap layer includes a rectangular periphery and each of the one or more bores is positioned proximate a respective corner of the cap layer.
12. An electronic device comprising an electronic component including a substrate having a main surface on which a functional unit is formed, a cap layer defining a cavity enclosing and covering the functional unit, and a first resin layer covering the cap layer and the main surface, the first resin layer including one or more bores and a solder layer having a thickness less than a thickness of the first resin layer disposed within the one or more bores, the cap layer being provided with holes communicating an inside of the cavity with an outside of the cavity.
13. The electronic device of claim 12 further comprising a printed circuit board including electrode pads, each of the electrode pads disposed within a corresponding bore and bonded to the solder layer in the corresponding bore.
14. The electronic device of claim 13 further comprising a second resin layer sealing the printed circuit board and the electronic component.
15. The electronic device of claim 12 wherein the functional unit is one of a surface acoustic wave element or a film bulk acoustic resonator.
16. The electronic device of claim 12 wherein the substrate includes a piezoelectric material.
17. The electronic device of claim 12 wherein the cap layer includes silicon dioxide and between zero and 20 atomic percent carbon relative to silicon in the silicon dioxide.
18. The electronic device of claim 12 wherein the one or more holes are formed in a ceiling of the cap layer.
19. The electronic device of claim 12 wherein edges of each hole are defined by both the cap layer and the main surface of the substrate.
20. The electronic device of claim 12 wherein the solder layer is in electrical communication with the functional unit through a metal layer disposed on the main surface of the substrate.