Surface acoustic wave filter packaging

• US 20040219887A1
• Filed: 06/03/2004
• Published: 11/04/2004
• Est. Priority Date: 12/06/1999
• Status: Active Grant

• Current Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Original Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Inventors: Vakilian, Nooshin D.
• Granted Patent: US 7,016,655 B2
• Time in Patent Office: Days
• US Class Current: 455/73
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H03H 9/0542 consisting of a lateral arrangement H03H9/0566 takes precedence
• CPC Class Codes: H03H 9/059 consisting of mounting pads or bumps
• CPC Class Codes: H03H 9/1085 the enclosure being defined by a non-uniform sealing mass covering the non-active sides of the BAW device

Abstract

A system that provides packaging for a surface acoustic wave filter in such a way that the surface acoustic wave filter is capable of integration with a number of additional electronic devices on an integrated substrate. The surface acoustic wave filter is mounted in a “flip chip” configuration that enables the surface of the surface acoustic wave filter to be protected from a molding compound during and after the encapsulation of the surface acoustic wave filter and other circuitry contained on the integrated substrate. The manner in which the surface acoustic wave filter is packaged provides a great reduction in cost and occupied real estate on the integrated substrate, in that, the surface acoustic wave filter is mounted in such as way as not to require conventionally used ceramic packaging that encases the surface acoustic wave filter. An air gap is preserved between the surface acoustic wave filter side of the surface acoustic wave filter and the integrated substrate on which it is mounted. This air gap ensures proper operation of the surface acoustic wave filter. In addition, a passivation layer is deposited on the surface acoustic wave filter side of the surface acoustic wave filter before it is mounted in the “flip chip” configuration, thereby provided a degree of protection of the surface acoustic wave filter side of the surface acoustic wave filter.

Claims

1-20. -20. (canceled)

21. A wireless transceiver that receives a signal, the wireless transceiver comprising:

a surface acoustic wave filter die that receives a signal and that filters the signal; and

the surface acoustic wave filter die is mounted in a flip chip configuration on an integrated substrate, and a passivation layer is deposited on an active region of the surface acoustic wave filter die prior to the surface acoustic wave filter die being mounted on the integrated substrate.

22. The wireless transceiver of claim 21, further comprising an antenna that receives the signal and provides the signal to the switching circuitry.

23. The wireless transceiver of claim 21, further comprising at least one additional circuitry mounted on a motherboard and receiving the signal.

24. The wireless transceiver of claim 21, wherein the wireless transceiver is a wireless communication device.

25. The wireless transceiver of claim 21, wherein the wireless transceiver is a cellular telephone.

26. The wireless transceiver of claim 21, wherein the signal is an encoded speech signal.

27. The wireless transceiver of claim 21, wherein the flip chip configuration of mounting of the surface acoustic wave filter die on the integrated substrate provides an air gap between the surface acoustic wave filter die and the integrated substrate.

28. The wireless transceiver of claim 21, wherein the passivation layer is a dielectric material.

29. The wireless transceiver of claim 21 wherein the passivation layer covers the surface acoustic wave filter die active region.

30. A multi-chip module comprising:

a surface acoustic wave filter die;

a passivation layer deposited on the surface acoustic wave filter die prior to the surface acoustic wave filter die being mounted on an integrated substrate;

a surface mounted circuitry, the surface mounted circuitry comprises a switching circuitry;

a chip on board circuitry, the chip on-board circuitry comprises a low noise amplifier die and a mixer die; and

wherein each of the surface mounted circuitry and the chip on-board circuitry is mounted on the integrated substrate.

31. The multi-chip module of claim 30, wherein a molding compound encapsulates the surface acoustic wave filter die on the integrated substrate.

32. The multi-chip module of claim 30, wherein the multi-chip module is contained within a personal communication device.

33. The multi-chip module of claim 30, wherein the passivation layer is a dielectric material.

34. A method to package a surface acoustic wave (SAW) filter die, the method comprising:

passivating an active region of the surface acoustic wave filter die;

mounting the surface acoustic wave filter die on a plurality of contact pads on a substrate using a plurality of solder balls; and

encapsulating the surface acoustic wave filter die on the substrate.

35. The method of claim 34, further comprising covering the plurality of contact pads before passivating the active region of the surface acoustic wave filter die.

36. The method of claim 34, further comprising providing an air gap between the surface acoustic wave filter die and the substrate.

37. The method of claim 34, wherein a dielectric material is applied to the surface acoustic wave filter die to perform the passivation of the active region of the surface acoustic wave filter die.

38. The method of claim 34 wherein passivating the active region of the surface acoustic wave filter die comprises passivating a filter side of the surface acoustic wave filter die.