Method for array processing of surface acoustic wave devices

• US 6,928,718 B2
• Filed: 05/24/2001
• Issued: 08/16/2005
• Est. Priority Date: 06/06/2000
• Status: Expired due to Fees

• Current Assignee: Triquint Inc (Qorvo, Inc.)
• Original Assignee: Sawtek Incorporated (Qorvo, Inc.)
• Inventors: Carpenter, Charles
• Primary Examiner(s): Kim, Paul D
• Application Number:
  US09/864,918
• Publication Number:
  US 20020008438A1
• Time in Patent Office: 1,545 Days
• Field of Search: 29/253.5, 295/94, 295/95, 296/091, 298/34, 298/35, 310/313, 310/320, 310/366, 333/150, 333/187, 333/193, 333/195, 333/196, 156/250, 156/257, 156/277
• US Class Current: 29/594
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/16195 Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H03H 9/1071 the enclosure being defined by a frame built on a substrate and a cap, the frame having no mechanical contact with the SAW device
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing
• CPC Class Codes: Y10T 156/1064 Partial cutting [e.g., grooving or incising]
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/4908 Acoustic transducer
• CPC Class Codes: Y10T 29/49133 with component orienting
• CPC Class Codes: Y10T 29/49135 and shaping, e.g., cutting or bending, etc.

Abstract

An assembly and method for array processing of hermetically sealed Surface Acoustic Wave (SAW) Devices employs a non-conductive material having an array of spaced cavities extending into the material for receiving a SAW die face down, in a flip-chip arrangement. Each cavity has a peripheral recess dimensioned to receive a lid for hermetically sealing the die within the cavity. Conductive paths are provided from the interior of the cavity to the surface of the array for providing an electrical contact with the SAW die. Individual SAW devices are then provided by cutting along separation lines between adjacent cavities after a plurality of die have been hermetically sealed within its cavity.

Claims

1. A method for manufacturing an array of hermetically sealed surface acoustic wave (SAW) devices, the method comprising the steps of:

forming a unitary array of a material having opposing first and second surfaces and a plurality of spaced cavities extending into the array from the first surface;

forming a recess from the first surface around selected cavities;

providing at least two conductive paths from within each selected cavity to at least one of the first and second surfaces of the array;

inserting and attaching a SAW die face down, in a flip-chip arrangement, into at least some of the selected cavities, each SAW die having conductive means electrically contacting the at least two conductive paths within the corresponding cavity;

solder sealing a metal lid in the recess over the inserted SAW die for hermetically sealing the SAW die within the cavity; and

then

separating the array into individual SAW devices along separation lines between adjacent cavities.

2. The method recited in claim 1, further comprising the step of maintaining spacing between adjacent cavities during the separation step by applying tape means over the sealed lids and the first surface.

3. The method recited in claim 1, wherein the solder sealing step comprises the steps of:

placing the lid over at least some of the plurality of spaced cavities;

placing solder about a periphery of each lid; and

then

treating the array having the lids and solder thereon so as to hermetically seal each lid thereto.

4. The method recited in claim 3, wherein the treating step comprises heating the array to effectuate sealing of the lids.

5. The method recited in claim 1, further comprising the steps of:

placing a continuous tape across the first surface and the sealed lids prior to the separating step;

undertaking the separating step from the second surface while maintaining continuity of the tape across the first surface; and

then

removing the individual components from the tape.

6. The method recited in claim 1, further comprising the step of forming the unitary array from a non-conductive material.

7. The method recited in claim 6, wherein the unitary array comprises a ceramic.

8. The method recited in claim 1, wherein the lid sealing step comprises the step of hermetically sealing the cavity from an ambient environment.

9. An assembly for manufacturing individual surface acoustic wave (SAW) devices comprising:

a unitary array of a nonconductive material having opposing first and second surfaces and a plurality of spaced cavities extending into the array from the first surface;

a SAW die carried face down, in a flip-chip arrangement, within at least some of the plurality of spaced cavities;

a recess formed around selected cavities extending from the first surface,

at least two electrically conductive paths from the SAW die within each selected cavity to an at least one of the first and second surfaces of the array;

a lid solder sealed in each recess of the selected cavities over the inserted SAW die for hermetically sealing the die therein; and

wherein the array is separated along separation lines between adjacent cavities to form individual SAW devices therefrom.

10. The assembly recited in claim 9, wherein each recess has a dimension greater than that of the corresponding cavity in order to form an area of overlap, and wherein the lid sealed in each recess engages the area of overlap.