# US 5,702,775 A · Microelectronic device package and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,702,775 A - Document ID: US5702775A - Status: Granted - Kind: A - Application number: 08/578,801 - Filed: 1995-12-26 - Granted: 1997-12-30 - Earliest claimed: 1995-12-26 - Assignees: Motorola, Inc. - Inventors: Michael John Anderson; Gary Carl Johnson; Mark Phillip Popovich; Jeffrey Eames Christensen - Web page: https://patentgrep.com/patent/US5702775A ## CPC - H03H 9/1064: {for surface acoustic wave [SAW] devices} - H03H 3/08: for the manufacture of resonators or networks using surface acoustic waves - C09K 2323/061: Inorganic, e.g. ceramic, metallic or glass - H10W 74/00: Encapsulations, e.g. protective coatings - H10W 90/756: {between a chip and a stacked lead frame, conducting package substrate or heat sink} - Y10T 428/23: Sheet including cover or casing - Y10T 428/232: Encased layer derived from inorganic settable ingredient - Y10T 428/239: Complete cover or casing - Y10T 428/31511: Of epoxy ether - Y10T 428/3154: Of fluorinated addition polymer from unsaturated monomers - Y10T 428/31612: As silicone, silane or siloxane - Y10T 428/31623: Next to polyamide or polyimide - Y10T 428/31627: Next to aldehyde or ketone condensation product - Y10T 428/31649: Ester, halide or nitrile of addition polymer - Y10T 428/31663: As siloxane, silicone or silane - Y10T 428/31667: Next to addition polymer from unsaturated monomers, or aldehyde or ketone condensation product - Y10T 428/31721: Of polyimide - Y10T 428/31786: Of polyester [e.g., alkyd, etc.] - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method (38) for packaging a microelectronic device (10) and a device (10) packaged by the method (38). The method (38) includes a step of providing (42) a first material (16) on an active surface of the microelectronic device (10). The first material (16) has a first temperature coefficient of expansion. The method (38) also includes steps of heating (46) the microelectronic device (10) and the first material (16) to a predetermined first temperature and molding (48) a second material (20) about the microelectronic device (10) and the first material (16). The second material (20) has a second temperature coefficient of expansion less than that of the first material (16). A final step of cooling (50) the first material (16), the second material (20) and the microelectronic device (10) provides a packaged microelectronic device (30). ## Claims ### Claim 1 An acoustic wave device packaged by a method for packaging an acoustic wave device, said method comprising steps of: providing a first material having a temperature coefficient of expansion of one hundred parts per million per degree Centigrade or more on an active surface of said acoustic wave device; exposing said first material to ultraviolet radiation to provide enhanced adhesion to a second material; molding said second material having a temperature coefficient of expansion of less than thirty parts per million per degree Centigrade about said acoustic wave device and said first material, said second material having a second temperature coefficient of expansion less than that of said first material; and cooling said first material, said second material and said acoustic wave device to provide a packaged acoustic wave device having a void between said acoustic wave device and said first material. ### Claim 2 An acoustic wave device package comprising: a first material having a temperature coefficient of expansion of one hundred parts per million per degree Centigrade or more disposed above a gap over a surface of an acoustic wave device; and a second material having a temperature coefficient of expansion of less than thirty parts per million per degree Centigrade disposed surrounding said first material and atop said acoustic wave device. ### Claim 3 (depends on 2) A package as claimed in claim 2, wherein said acoustic wave device comprises a substrate chosen from a group consisting of lithium niobate, lithium tantalate or gallium arsenide. ### Claim 4 (depends on 2) A package as claimed in claim 2, wherein said first material comprising dimethyl siloxane and having a temperature coefficient of expansion of one hundred parts per million per degree Centigrade or more. ### Claim 5 (depends on 2) A package as claimed in claim 2, wherein said second material is chosen from a group consisting of novolac epoxy, polyester, phenolic, liquid crystal polymer, polytetrafluoroethylene, polyaryletherketone and polyimide. ### Claim 6 (depends on 5) A package as claimed in claim 5, wherein said second material substantially surrounds said first material and said acoustic wave device. ### Claim 7 In a radio, an acoustic wave device package comprising: a first material having a temperature coefficient of expansion of one hundred parts per million per degree Centigrade or more disposed above a gap disposed over an active area of an acoustic wave device; and a second material having a temperature coefficient of expansion of less than thirty parts per million per degree Centigrade disposed surrounding said first material and atop said acoustic wave device. ### Claim 8 (depends on 7) A package as claimed in claim 7, wherein said acoustic wave device comprises a substrate chosen from a group consisting of lithium niobate, lithium tantalate or gallium arsenide. ### Claim 9 (depends on 7) A package as claimed in claim 7, wherein said second material substantially surrounds said first material and said acoustic wave device. ### Claim 10 (depends on 9) A package as claimed in claim 9, wherein said second material is chosen from a group consisting of novolac epoxy, polyester, phenolic, liquid crystal polymer, polytetrafluoroethylene, polyaryletherketone and polyimide. ### Claim 11 A frequency selection component packaged by a method for packaging a acoustic wave device, said method comprising steps of: providing a first material on an active surface of said acoustic wave device, said first material having a first temperature coefficient of expansion of one hundred parts per million per degree Centigrade or more; treating said first material to provide enhanced adhesion to said second material, wherein said treating step includes exposing said first material to ultraviolet radiation; heating said acoustic wave device and said first material to a predetermined first temperature in a range of from 100 to 250 degrees Centigrade; molding a second material about said acoustic wave device and said first material, said second material having a second temperature coefficient of expansion less than thirty parts per million per degree Centigrade; and cooling said first material, said second material and said acoustic wave device to provide a packaged acoustic wave device including a void between said acoustic wave device and said first material. ### Claim 12 An acoustic wave device packaged by a method comprising steps of: providing a first material on an active surface of said acoustic wave device, said first material having a first temperature coefficient of expansion of one hundred parts per million per degree Centigrade or more; treating said first material to provide enhanced adhesion to said second material, wherein said treating step includes exposing said first material to ultraviolet radiation; heating the acoustic wave device and the first material to a predetermined first temperature in a range of from 100 to 250 degrees Centigrade; molding a second material about said acoustic wave device and said first material, said second material having a second temperature coefficient of expansion less than thirty parts per million per degree Centigrade; and cooling said first material, said second material and said acoustic wave device to provide a packaged acoustic wave device including a void between said acoustic wave device and said first material.