Claims
- 1. A method of forming a package, comprising:
placing a film against a flip-chip assembly, wherein the flip-chip assembly includes a die, an electrical connection, and a mounting substrate; underfilling the die with underfill material; curing the underfill material; and after beginning curing the underfill material, removing the film.
- 2. The method according to claim 1, wherein the film includes a tacky film.
- 3. The method according to claim 1, wherein the film includes a tacky film, and wherein curing the underfill material is carried out under heat that causes the tacky film to release from the flip-chip assembly.
- 4. The method according to claim 1, wherein after beginning curing the underfill material and removing the film, curing includes:
curing the underfill material that is in contact with the film; removing the film; and thereafter curing the underfill material that is between the die and the mounting substrate.
- 5. The method according to claim 1, wherein after beginning curing the underfill material and removing the film, curing includes:
curing the underfill material that is in contact with the film by conductive heat transfer from a mold press; removing the film; and thereafter curing the underfill material that is between the die and the mounting substrate by placing the package into a curing oven.
- 6. The method according to claim 1, wherein after beginning curing the underfill material and removing the film, curing includes:
heating the package in a curing oven under conditions to cause the tacky film to release from the flip-chip assembly.
- 7. The method according to claim 1, wherein after beginning curing the underfill material and removing the film, curing includes:
heating the package in a curing oven under conditions to cause the tacky film to release from the flip-chip assembly, wherein heating includes a first temperature ramp to a temperature range from about 100° C. to about 180° C., a temperature hold at a temperature in this range, a second temperature ramp to a temperature range from about 140° C. to about 260° C., and cooling.
- 8. The method according to claim 1, wherein after beginning curing the underfill material and removing the film, curing includes:
heating the package in a curing oven under conditions to cause the tacky film to release from the flip-chip assembly, wherein heating includes a single step temperature ramp to a temperature in a range from about 140° C. to about 240° C.; and cooling.
- 9. The method according to claim 1, wherein the underfill material has a viscosity that causes it to draw between the die and the mounting substrate without the assistance of a pressure differential.
- 10. The method according to claim 1, wherein the underfill material has a viscosity that causes it to draw between the die and the mounting substrate, further including:
flowing the underfill material from a first edge of the die to an opposite, second edge of the die by a pressure differential.
- 11. A method of forming a package, comprising:
stretching a flexible film over die that is mounted on a mounting substrate to seal the flexible film thereupon; flowing underfill material between the die and the mounting substrate with a source and a vent; heating the underfill material to a first curing temperature; and after reaching the first curing temperature, removing the flexible film.
- 12. The method according to claim 11, wherein the film is selected from a non-tacky film and a tacky film.
- 13. The method according to claim 11, wherein the film includes a tacky film, and wherein heating the underfill material to a first curing temperature is carried out to cause the underfill material to cure, and wherein the first curing temperature is reached to a temperature range from about 100° C. to about 180° C.; and
wherein the second curing temperature causes the tacky film to release from the die and mounting substrate, and wherein the second curing temperature is reached to a temperature range from 140° C. to about 260° C.
- 14. The method according to claim 11, wherein the film is a non-tacky film and wherein after heating the underfill material to a first curing temperature and removing the film, curing includes:
gelling the underfill material that is in contact with the film; removing the film; and the process further including:
curing the underfill material that is between the die and the mounting substrate.
- 15. The method according to claim 11, wherein heating the underfill material to a first curing temperature includes:
heating along a first temperature ramp to a first temperature range from about 100° C. to about 180° C.; and further including:
holding the first temperature; heating along a second ramp to a temperature range from about 140° C. to about 260°0 C.; and cooling.
- 16. The method according to claim 11, wherein the underfill material has a viscosity that causes it to draw between the die and the mounting substrate, further including:
flowing the underfill material from a first edge of the die to an opposite, second edge of the die by a pressure differential.
- 17. A chip package comprising:
a die; a mounting substrate; an electrical connection disposed between the mounting substrate and the die; a cured underfill material including a fillet portion, and an interstitial portion disposed between the die and the mounting substrate, wherein the fillet portion includes a surface roughness and pattern that is characteristic of an interstitial film surface roughness and pattern.
- 18. The chip package according to claim 17, wherein the interstitial film surface roughness and pattern is derived from a film selected from a tacky film and a non-tacky film.
- 19. The chip package according to claim 17, wherein the fillet portion exhibits a single-stage solidification profile in cross section.
- 20. The chip package according to claim 17, wherein the fillet portion exhibits a symmetrical rectilinear or other controllable footprint on the mounting substrate.
- 21. The chip package according to claim 17, wherein the fillet portion exhibits a concave curvilinear cross-sectional profile.
- 22. The chip package according to claim 17, wherein the electrical connection disposed between the mounting substrate and the die is selected from a ball grid array, a collapsed ball grid array, and a pin grid array.
- 23. A chip-packaging process system comprising:
a die; a mounting substrate; an electrical connection disposed between the mounting substrate and the die; a tacky film that is disposed over the die and stretched onto the mounting substrate; a mold press that gives a shape to the film; an underfill material disposed between the die and the mounting substrate; and an underfill inlet and outlet system that communicates through the film.
- 24. The chip-packaging process system according to claim 23, wherein the underfill inlet and outlet system includes an underfill conduit and a vent.
- 25. The chip-packaging process system according to claim 23, wherein the underfill material includes a fillet shape disposed between the die and the mounting substrate, and wherein the a mold press that gives shape to the film includes a heater element disposed at the fillet.
- 26. The chip-packaging process system according to claim 23, further including:
a first heating source for ramping the temperature of the underfill material to a first cure state; and a second heating source for causing the tacky film to release from the die, the fillet, and the mounting substrate.
RELATED APPLICATIONS
[0001] The application is a divisional of U.S. patent application Ser. No. 10/032,115, filed Dec. 21, 2001, which is incorporated herein by reference.
Divisions (1)
|
Number |
Date |
Country |
Parent |
10032115 |
Dec 2001 |
US |
Child |
10774869 |
Feb 2004 |
US |