Chip package structure and method for manufacturing the same

1. A method for manufacturing a semiconductor package structure, comprising steps of:

forming a plurality of conductive pastes on a matrix lead frame, wherein a groove is located within a predetermined distance from each conductive paste on the lead of the matrix lead frame;

partially curing the conductive pastes so that the conductive pastes are in a semi-cured, tacky and semi-solid state;

preparing at least one chip with a plurality of bumps thereon;

electrically connecting the chip and the lead of the matrix lead frame by implanting the plurality of bumps into the semi-cured conductive pastes, wherein the groove on the lead of the matrix lead frame is configured to receive and confine overflowed semi-cured conductive pastes;

curing the semi-cured conductive pastes to completely secure the bumped chip; and

forming an encapsulating material to cover the lead frame and the chip.

2. The method for manufacturing a semiconductor package structure of claim 1 , wherein preparing at least one chip with a plurality of bumps thereon comprises forming gold bumps, copper pillars, gold stud bumps, copper stud bumps, or gold/copper metal composite bumps.

3. The method for manufacturing a semiconductor package structure of claim 1 , further comprising curing the encapsulating material.

4. The method for manufacturing a semiconductor package structure of claim 3 , further comprising singulating the matrix lead frame.

5. The method for manufacturing a semiconductor package structure of claim 1 , wherein the matrix lead frame is a pre-molded matrix lead frame.

6. The method for manufacturing a semiconductor package structure of claim 1 , wherein forming an encapsulating material covering the lead frame and the chip thereon is selected from the means of injection molding, overmolding or underfill potting.

7. The method for manufacturing a semiconductor package structure of claim 1 , wherein forming a groove located within a predetermined distance from each conductive paste on the lead of the matrix lead frame, comprises forming a surrounding groove around the conductive paste.

8. A semiconductor package comprising:

a matrix lead frame having a plurality of inner leads and outer leads, and a groove located at each inner lead;

a semiconductor chip having a plurality of bumps for electrically connecting the semiconductor chip and the inner lead of the matrix lead frame;

a plurality of semi-cured conductive pastes used to mount the semiconductor chip on the inner lead of the matrix lead frame; and

an encapsulating material used to seal and cover the semiconductor chip and the matrix lead frame,

wherein the groove is located within a predetermined distance from the conductive paste, and when the plurality of bumps of the semiconductor chip are implanted into the semi-cured conductive paste, the groove is configured to receive and confine overflowed conductive pastes in the groove, and the semi-cured conductive paste is fully cured to completely secured the semiconductor chip on the matrix lead frame.

9. The semiconductor package of claim 8 , wherein the bumps include gold bumps, copper pillars, gold stud bumps, copper stud bumps, or gold/copper metal composite bumps.

10. The semiconductor package of claim 8 , wherein the encapsulating material is further cured and the matrix lead frame is singulated.

11. The semiconductor package of claim 8 , wherein the matrix lead frame is a pre-molded lead frame.

12. The semiconductor package of claim 11 , wherein the pre-molded lead frame comprises a supporting carrier, a plurality of leads including inner leads and outer leads located on the supporting carrier, and a second encapsulating material that is semi-cured, wherein the second encapsulating material is coated on a tape that is subsequently disposed on a top surface of the inner leads to spread and cover the lead frame.

13. The semiconductor package of claim 12 , wherein the tape is subsequently removed and the second encapsulating material is cured.

14. The semiconductor package of claim 8 , wherein the groove is configured to surround the conductive paste to avoid overflowed conductive pastes.

15. A method for manufacturing a pre-molded lead frame package comprising steps of:

forming a semi-cured encapsulant between a plurality of leads of a matrix lead frame and a top surface of a supporting carrier;

forming a pre-molded lead frame by curing the semi-cured encapsulant;

bonding at least one chip with a plurality of bumps on the plurality of leads of the matrix lead frame, each chip being electrically connected to a part of the plurality of leads of the matrix lead frame through the plurality of bumps;

forming a groove on each lead, said groove configured to receive and confine overflowed bumps to avoid bump spreading;

encapsulating the chips and the matrix lead frame; and

forming a package by singulating the encapsulated chips and the encapsulated matrix lead frame, wherein the pre-molded lead frame package comprises one of the encapsulated chips and a part of the encapsulated matrix lead frame.

16. The method for manufacturing a pre-molded lead frame package of claim 15 , wherein forming a semi-cured encapsulant between a plurality of leads of a matrix lead frame and a top surface of a supporting carrier comprises coating a semi-cured encapsulant on a bottom surface of a tape, disposing the tape onto a top surface of the leads of the matrix lead frame during a lamination process, and removing the tape.

17. The method for manufacturing a pre-molded lead frame package of claim 16 , wherein coating a semi-cured encapsulant on a bottom surface of a tape comprises dipping, screen-printing, painting, spin-coating or spraying a semi-cured encapsulant on a bottom surface of a tape.

18. The method for manufacturing a pre-molded lead frame package of claim 15 , wherein forming a groove on each lead comprises forming a groove surrounding the plurality of bump.

19. The method for manufacturing a pre-molded lead frame package of claim 15 , wherein forming an encapsulating material covering the lead frame and the chip thereon is selected from the means of injection molding, overmolding or underfill potting.

20. The method for manufacturing a pre-molded lead frame package of claim 15 , wherein bonding at least one chip with a plurality of bumps on the leads of the matrix lead frame includes directly connecting the bumps to the leads of the matrix lead frame by thermo-ultrasonic bonding.

21. The method of manufacturing a pre-molded lead frame package of claim 15 , wherein the pre-molded lead frame packages is a Quad Flat Non-leaded (QFN) package.