Apparatus and methods of forming an interconnect between a workpiece and substrate
Embodiments of an apparatus and methods of forming interconnect between a workpiece and substrate and its application to packaging of microelectronic devices are described herein. Other embodiments may be described and claimed.
1. A method of forming an interconnect between a workpiece and a bumped substrate with a low temperature glass transition film, comprising:
forming a plurality of indentations in the film;
applying flux to the indentations to form a flux loaded film;
placing the flux loaded film on the bumped substrate;
heating the bumped substrate and the flux loaded film to form flux coated solder bumps on the bumped substrate; and
reflowing the bumped substrate to form the interconnect with the workpiece.
2. The method of claim 1 , wherein a glass transition temperature of the film is between 50 and 180 degrees Celsius.
3. The method of claim 1 , wherein the film is formed of a polyester.
4. The method of claim 1 , wherein the film is formed of a thermoplastic polymer.
5. The method of claim 3 , wherein the polyester is polyethylene terephthalate (PET).
6. The method of claim 4 , wherein the thermoplastic is polymethyl methacrylate (PMMA).
7. A method of forming a wafer level package, comprising:
applying flux to an embossed low glass transition temperature film;
positioning the embossed low glass transition temperature film on a bumped substrate;
placing a workpiece on the embossed low glass transition temperature film; and
heating the embossed low glass transition temperature film, bumped substrate, and workpiece to form an interconnect in the wafer level package.
8. The method of claim 7 , wherein a glass transition temperature of the embossed low glass transition temperature film is between 50 and 180 degrees Celsius.
9. The method of claim 7 , wherein a glass transition temperature of the embossed low glass transition temperature film is approximately between 65° C. and 100° C.
10. The method of claim 7 , further including applying a solder paste film to the embossed low glass transition temperature film.
11. The method of claim 7 , wherein a plurality of solder bumps on the bumped substrate comprise tin.
12. The method of claim 8 , wherein a thickness of the embossed low glass transition temperature film ranges approximately between 1 and 150 microns.
13. An apparatus, comprising:
a substrate with solder bumps attached to the substrate, wherein the solder bumps are separated by a gap;
a low glass transition temperature film material positioned in the gap;
an underfill material adjacent to the low glass transition temperature film material;
a workpiece comprising a plurality of bond-pads, wherein the workpiece is connected to the substrate through the bond-pads and the solder bumps.
14. The apparatus of claim 13 , wherein a glass transition temperature of the low glass transition temperature film is between 50 and 180 degrees Celsius.
15. The apparatus of claim 13 , wherein a glass transition temperature of the low glass transition temperature film is approximately between 65° C. and 100° C.
16. The apparatus of claim 13 , further including a flux and a solder paste adjacent to the low glass transition temperature film.
17. The apparatus of claim 13 , wherein the solder bumps on the substrate comprise copper.
18. The apparatus of claim 13 , wherein the low glass transition temperature film material is a thermoplastic polymer.
19. The apparatus of claim 13 , wherein the low glass transition temperature film material is an epoxy.
20. The apparatus of claim 14 , wherein a thickness of the low glass transition temperature film ranges approximately between 1 and 150 microns.