A process for fabricating a semiconductor package which includes using an exothermically active nanoparticle paste to join an electrode of a semiconductor die to a support body.
Description
SUMMARY OF THE FIGURES
FIG. 1 illustrates a selected step in a process according to the present invention.
FIG. 2 illustrates a cup-shaped conductive clip suitable as a support body in an example of a process according to the present invention.
Claims
1. A process for fabricating a power semiconductor device, comprising:
disposing a mass of electrically conductive and exothermically active nanoparticle paste between an electrically conductive electrode of a semiconductor die and an electrically conductive support body;applying energy to a portion of said mass of electrically conductive nanoparticle paste long enough to initiate an exothermic reaction to melt said mass; andcooling said molten mass to join said electrically conductive electrode to said electrically conductive support body.
2. The process of claim 1, wherein said applying step is discontinued after said exothermic reaction is initiated but before the completion of said exothermic reaction.
3. The process of claim 1, wherein said conductive support body is a die pad portion of a lead frame.
4. The process of claim 1, wherein said conductive support body is a die pad on a circuit board.
5. The process of claim 1, wherein said conductive support body is a die pad on an IMS.
6. The process of claim 1, wherein said conductive support body is a die pad on a DBC.
7. The process of claim 1, wherein said nanoparticles are less than 200 nm in diameter.
8. The process of claim 1, wherein said support body is a conductive clip.
9. The process of claim 1, wherein said support body is a can-shaped conductive clip.
10. The process of claim 1, wherein said paste further includes glass nanoparticles.
11. The process of claim 1, wherein said paste includes pure nanoparticles.
12. The process of claim 11, wherein said pure nanoparticles are comprised of one of silver, copper, and bismuth.
13. The process of claim 1, wherein said paste includes alloyed nanoparticles.
14. The process of claim 13, wherein said alloyed nanoparticles are one of silver/copper alloy, bismuth/silver alloy, silver/aluminum alloy, tin silver alloy, and tin/bismuth/copper ternary alloys.
15. The process of claim 1, wherein said energy is applied from one of an infrared source, an ultraviolet source, or a convention oven.
16. The process of claim 1, wherein a spark applies said energy.
17. The process of claim 1, wherein a hot tipped instrument applies said energy.
18. The process of claim 1, wherein said nanoparticles are comprised of one of nickel, copper, and aluminum.
19. A process for assembling a semiconductor device, comprising:
coating an electrode of a semiconductor die with an exothermically active nanoparticle paste;coating a conductive support with an exothermically active nanoparticle paste; andplacing the two coatings of nanoparticle paste in contact to commence an exothermic reaction to melt said pastes.
Patent Application
20070231960
