Methods and apparatuses for microelectronic assembly having a material with a variable viscosity around a MEMS device

• US 20060214246A1
• Filed: 03/24/2005
• Published: 09/28/2006
• Est. Priority Date: 03/24/2005
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Garcia, Jason A.
• Granted Patent: US 7,352,039 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: B81B 7/0058 for protecting against damages due to external chemical or mechanical influences, e.g. shocks or vibrations
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/1461 MEMS

Abstract

Various methods and apparatuses are described in which a micro-electro-mechanical systems (MEMS) device is encapsulated with a material having a variable viscosity with a viscosity value high enough to retard foreign material from contacting the MEMS device during an electronic package assembly process. The material having the variable viscosity may be affixed to a cavity area surrounding the MEMS device prior to an epoxy being dispensed onto the electronic package assembly. The temperature and pressure conditions of the electronic package assembly process may be controlled to ensure when the epoxy is dispensed that the material having the variable viscosity has a high enough viscosity value to retard foreign material from contacting the MEMS device during the electronic package assembly process.

Claims

1. A method, comprising:

encapsulating a micro-electro-mechanical systems (MEMS) device with a material having a variable viscosity with a viscosity value high enough to retard foreign material from contacting the MEMS device during an electronic package assembly process;

dispensing the material having the variable viscosity to a cavity area surrounding the MEMS device to affix the material to the cavity area prior to an epoxy being dispensed onto the electronic package assembly; and

controlling temperature and pressure conditions of the electronic package assembly process to ensure when the epoxy is dispensed that the material having the variable viscosity has a high enough viscosity value to retard foreign material from contacting the MEMS device during the electronic package assembly process.

2. The method of claim 1, wherein the material that has the variable viscosity value when at a temperature of between 20% above and 20% below the normal operating temperature of the MEMS device to allow the uninhibited movement of moveable parts associated with the MEMS device.

3. The method of claim 1, further comprising:

controlling temperature and pressure conditions of the material having the variable viscosity after the epoxy has cured to phase change the material to allow the material to be removed from around the MEMS component.

4. A computer readable medium containing instructions to cause a machine to perform the operations in the method of claim 1.

5. An electronic package assembly with the MEMS device created by the method of claim 1.

6. An electronic package assembly with the MEMS device created by the method of claim 3.

7. The method of claim 1, wherein the material that has a variable viscosity value is an Indium-based solder compound with a melting point equal to or greater than 157 degrees Celsius (C.).

8. The method of claim 1, further comprising:

affixing the material having the variable viscosity to the cavity area by creating a chemical bond between the material having the variable viscosity and the cavity area.

9. A microelectronic assembly, comprising:

a MEMS substrate;

a MEMS device on the MEMS substrate, the MEMS device having a MEMS component which is movable relative to the MEMS substrate;

a cavity area surrounding the MEMS device at least partially formed by the MEMS substrate; and

a material having a variable viscosity filling the cavity area, wherein the material has a viscosity value high enough to prevent foreign material from contacting the MEMS device during a manufacturing packaging process but later allows the MEMS device to operate freely at a normal operating temperature.

10. The microelectronic assembly of claim 9, wherein the material that has a variable viscosity value is a Bismuth-based alloy solder compound with a melting point equal to or greater than 47 C.

11. The microelectronic assembly of claim 9, wherein the material that has a variable viscosity value is a translucent plastic polymer with a melting point above 100 C but below 150 C.

12. The microelectronic assembly of claim 9, wherein the material having a variable viscosity is electrically non-conductive.

13. The microelectronic assembly of claim 9, wherein the cavity area is a hydrophilic region, the material is a hydrophilic compound, and an area surrounding the cavity area is a hydrophobic region to affix the material to the cavity area around the MEMS.

14. A computer readable medium containing instructions to cause a machine to create the microelectronic assembly of claim 9.

15. The microelectronic assembly of claim 9, wherein the material to affix to the cavity area around the MEMS device prior to an epoxy being dispensed during the manufacturing packaging process.

16. A microelectronic assembly, comprising:

a MEMS substrate with a channel formed in the MEMS substrate;

a MEMS device on the MEMS substrate; and

a cavity area surrounding the MEMS device at least partially formed by the MEMS substrate; and

a material having a variable viscosity filling the cavity area, wherein the material has a variable viscosity with a viscosity value high enough to prevent foreign material from contacting the MEMS device during an electronic package assembly process, wherein the material having the variable viscosity to affix to the cavity area around the MEMS device prior to an epoxy being dispensed during the electronic package assembly process and the material is removed via the channel after the epoxy has cured.

17. The microelectronic assembly of claim 16, wherein the material that has a variable viscosity value is a Tin-based solder compound with a melting point equal to or greater than 135 C.

18. The microelectronic assembly of claim 16, wherein the material is affixed to the cavity area by creating a mechanical bond between the material having the variable viscosity and the cavity area.

19. The microelectronic assembly of claim 16, wherein the MEMS device is an optical device and the material is a translucent plastic polymer with melting point above 100 C.

20. The microelectronic assembly of claim 16, wherein the material that has the variable viscosity value is a hydrophilic compound and a thin film creates a hydrophilic surface in the cavity area.

21. A computer readable medium containing instructions to cause a machine to create the microelectronic assembly of claim 16.