Semiconductor package structures and methods of manufacture
Methods of forming semiconductor packages include providing a lead frame having leads and no tie-bars. Tape is attached to the lead frame and one or more semiconductor die are coupled therewith. Electrical contacts of the die are interconnected with the leads using electrical connectors. An encapsulated assembly is formed by at least partially encapsulating the die and electrical connectors. The assembly is singulated to form a semiconductor package. The tape is detached from the package or encapsulated assembly. One or more die attach flags may be attached to the tape and the die may be attached thereto. Semiconductor packages formed using the methods include one or more semiconductor die at least partially encapsulated, pins exposed through the encapsulant, electrical connectors within the encapsulant and electrically interconnecting the pins with electrical contacts of the die, and no tie-bars coupling the die with the pins. Packages may also include die attach flags.
1. A method of forming a no tie-bar semiconductor package, comprising:
providing a lead frame comprising a plurality of leads, the lead frame comprising no tie-bars;
attaching a tape to the lead frame;
coupling one or more semiconductor die with the tape, wherein the one or more semiconductor die comprises a plurality of electrical contacts;
electrically interconnecting one or more of the electrical contacts with one or more of the leads using electrical connectors;
forming an encapsulated assembly, by at least partially encapsulating the one or more semiconductor die and at least partially encapsulating each of the electrical connectors, using an encapsulant;
singulating the encapsulated assembly to form a semiconductor package; and
detaching the tape from one of the encapsulated assembly and the semiconductor package.
2. The method of claim 1 , wherein the semiconductor package comprises one of a power converter and a power controller.
3. The method of claim 1 , wherein the lead frame comprises no die attach flags.
4. The method of claim 1 , wherein the electrical connectors comprise wirebonds.
5. The method of claim 1 , further comprising attaching one or more die attach flags to the tape, wherein coupling the one or more semiconductor die with the tape comprises attaching the one or more semiconductor die to the one or more die attach flags using a die attach material.
6. The method of claim 5 , further comprising using vacuum assist to hold down the one or more die attach flags while attaching the one or more semiconductor die to the one or more die attach flags, and using vacuum assist while electrically interconnecting one or more of the electrical contacts with one or more of the leads using the electrical connectors.
7. The method of claim 1 , wherein the tape is configured to retain its shape and adhesiveness at temperatures exceeding 240 degrees Celsius.
8. The method of claim 1 , wherein the tape comprises an adhesive layer of 3 mils or less.
9. The method of claim 1 , wherein none of the electrical contacts of the one or more semiconductor die are exposed through the encapsulant of the semiconductor package.
10. The method of claim 1 , wherein the method comprises no etching step, apart from any etching used for singulation, after the one or more semiconductor die are coupled with the tape.
11. The method of claim 1 , wherein the method comprises only one encapsulating step.
12. The method of claim 1 , wherein the method comprises no sawing step, apart from any sawing used for singulation, after at least partially encapsulating the one or more semiconductor die using the encapsulant.
13. A method of forming a no tie-bar semiconductor package, comprising:
providing a lead frame comprising a plurality of leads, the lead frame comprising no tie-bars and no die attach flags;
attaching a tape to the lead frame;
attaching a plurality of die attach flags to the tape;
attaching a plurality of semiconductor die to the die attach flags using a die attach material, wherein each of the semiconductor die comprises a plurality of electrical contacts;
electrically interconnecting one or more of the electrical contacts with one or more of the leads using electrical connectors;
forming an encapsulated assembly, by at least partially encapsulating each of the semiconductor die and at least partially encapsulating each of the electrical connectors, using an encapsulant;
singulating the encapsulated assembly to form a semiconductor package; and
detaching the tape from one of the encapsulated assembly and the semiconductor package;
wherein the semiconductor package comprises a flat no-leads package.
14. The method of claim 13 , wherein the tape is configured to retain its shape and adhesiveness at temperatures exceeding 240 degrees Celsius and wherein the tape comprises an adhesive layer of 3 mils or less.
15. The method of claim 13 , wherein none of the electrical contacts of the plurality of semiconductor die are exposed through the encapsulant of the semiconductor package.
16. The method of claim 13 , wherein the method comprises no etching step, apart from any etching used for singulation, after the plurality of semiconductor die are attached to the die attach flags.
17. The method of claim 13 , wherein the method comprises only one encapsulating step.
18. The method of claim 13 , wherein the method comprises no sawing step, apart from any sawing used for singulation, after at least partially encapsulating the plurality of semiconductor die using the encapsulant.