Method of making a semiconductor device
View Patent ↗In one embodiment, a method for forming an electronic device includes providing a substrate having a plurality of electronic devices formed therein, forming a protective layer over a major surface of the substrate containing the plurality of electronic devices, forming a mold layer over the protective layer, thinning a major surface of the substrate opposite to the major surface containing the plurality of electronic devices, and removing the adhesive layer and the mold layer. In another embodiment, a zone coating layer can be included between the protective layer and the mold layer.
1. A method of fabricating a semiconductor device comprising:
providing a wafer having conductive structures formed on a first major surface;
depositing a protective layer onto the first major surface, the protective layer having a thickness deviation across the first major surface including a first portion thicker than a second portion; and
thereafter forming a mold layer on the protective layer using a molding apparatus, wherein the mold layer has an outer surface molded using the molding apparatus to be substantially flat thereby offsetting the thickness deviation of the protective layer.
2. The method of claim 1 , wherein forming the mold layer comprises forming the mold layer having a thickness greater than a thickness deviation of protective layer.
3. The method of claim 1 , wherein depositing the protective layer comprises spin-coating the protective layer onto the first major surface.
4. The method of claim 1 , further comprising reducing the thickness of the wafer by removing material from a second major surface of the wafer opposite to the first major surface after forming the mold layer.
5. The method of claim 4 , further comprising removing the protective layer by applying heat to the protective layer and sliding the wafer away from the protective layer, after reducing the thickness of the wafer.
6. The method of claim 4 , further comprising:
fixing the second major surface of the wafer to a tape after reducing the thickness of the wafer; and
separating the mold layer from the protective layer.
7. The method of claim 6 , further comprising removing the protective layer remaining on the first major surface of the wafer, after separating the mold layer.
8. The method of claim 1 , further comprising zone coating a top portion of the protective layer after the protective layer is deposited onto the first major surface and before forming the mold layer.
9. The method of claim 8 , wherein zone coating comprises forming a coating layer along the surface of the protective layer, and wherein the coating layer has a central zone and an edge zone, and wherein the central zone has less adhesive than the edge zone.
10. The method of claim 8 , further comprising mounting a tape on a second major surface of the wafer opposite to the first major surface, after forming the mold layer.
11. The method of claim 10 , further comprising zone separating to remove the mold layer from the coating layer after mounting the tape.
12. The method of claim 11 , further comprising removing the protective layer by applying heat to the protective layer and sliding the wafer away from the protective layer, after zone separating the mold layer from the coating layer.
13. A method for forming an electronic device comprising:
providing a substrate having a plurality of electronic devices formed adjacent a first major surface of the substrate;
forming a protective layer over the first major surface, wherein the protective layer has a thickness deviation across the first major surface;
thereafter forming a mold layer on the protective layer using a molding apparatus, wherein the mold layer has an outer surface molded using the molding apparatus to be substantially flat thereby offsetting the thickness deviation of the protective layer; and
removing material from a second major surface of substrate thereby reducing its thickness.
14. The method of claim 13 further comprising forming a coating layer after forming the protective layer and before forming the mold layer.
15. The method of 14 , wherein forming the coating layer comprises forming the coating layer by zone coating.
16. The method of claim 13 , wherein forming the protective layer comprises forming an adhesive layer, and wherein forming the mold layer comprises one of injection molding or overmolding.
17. A method for reducing the thickness of a substrate comprising
providing a substrate having first and second opposing major surfaces;
forming a protective layer over the first major surface, wherein the protective layer has a thickness deviation across the first major surface;
thereafter forming a mold layer on the protective layer using a molding apparatus, wherein the mold layer has an outer surface molded using the molding apparatus to be substantially flat thereby offsetting the thickness deviation of the protective layer; and
reducing the thickness of the substrate by removing material from the second major surface.
18. The method of claim 17 , wherein forming the protective layer comprises spin coating the protective layer onto the first major surface.
19. The method of claim 17 , wherein forming the protective layer comprises forming an adhesive layer, the method further comprising:
forming coating layer between the adhesive layer and the mold layer;
mounting the substrate to a tape after reducing the thickness of the substrate;
separating the mold layer from the coating layer; and
removing the adhesive layer from the substrate.
20. The method of claim 17 further comprising removing the protective layer by applying heat to the protective layer and sliding the substrate away from the protective layer.