Granted Patent B2

US 9,252,085 · App. 14/077,138 · Granted Feb 2, 2016

Abstract

Claims (58)

1. A method for packaging an integrated circuit (IC) comprising steps of:

attaching at least one die on a substrate;

attaching bond-wires from the die(s) to package terminal pads;

providing a thermo-degradable material in direct contact with the substrate, with the at least one die and with the bond-wires;

molding an encapsulant material that encapsulates the thermo-degradable material, the at least one die, and the bond-wires against the substrate; and

forming an air cavity between the encapsulant and the at least one die by decomposing the thermo-degradable material by temperature treatment.

2. A method for packaging an integrated circuit as claimed in claim 1 further comprising the step of dispensing the thermo-degradable material on the substrate.

3. An RF integrated circuit or an RF amplifier included in a package formed in accordance with the method of claim 2 , the RF integrated circuit or the RF amplifier comprising:

the at least one die on a substrate;

for each of the at least one die, at least a bond-wire connected from the die to at least one terminal pad attached to the package; and

the air cavity formed around the at least one die and the bond-wire by the decomposing of the thermo-degradable material.

4. A method for packaging an integrated circuit as claimed in claim 1 further comprising the step of dispensing the thermo-degradable material situated on the die and on the bond-wires.

5. An RF integrated circuit or an RF amplifier included in a package formed in accordance with the method of claim 4 , the RF integrated circuit or the RF amplifier comprising:

the at least one die on a substrate;

for each die, at least a bond-wire connected from the die to at least one terminal pad attached to the package; and

the air cavity formed around the at least one die and the bond-wire by the decomposing of the thermo-degradable material.

6. A method for packaging an integrated circuit as claimed in claim 1 ,

wherein molding the encapsulant material includes sealing the thermo-degradable material, the at least one die, and the bond-wires between the encapsulant material and the substrate,

further comprising the steps of evaporating excessive solvents included in the thermo-degradable material and permeating the decomposed thermo-degradable material and excessive solvents through the encapsulant material with the encapsulant material sealing the thermo-degradable material with the substrate, the at least one die and bond-wires, and

wherein forming the air cavity includes generating gas and solvent from the thermo-degradable material and permeating the gas and solvent through the encapsulant material while the die and bond wires are sealed by the encapsulant material to the substrate.

7. An RF integrated circuit or an RF amplifier included in a package formed in accordance with the method of claim 6 , the RF integrated circuit or the RF amplifier comprising:

the at least one die on a substrate;

for each die, at least a bond-wire connected from the die to at least one terminal pad attached to the package; and

the air cavity formed around the at least one die and the bond-wire by the decomposing of the thermo-degradable material.

8. A method for packaging an integrated circuit as claimed in claim 1 wherein the thermo-degradable material has a dielectric constant substantially different than 1 and is dispensed onto the substrate, the at least one die and the bond-wires.

9. A method for packaging an integrated circuit as claimed in claim 8 , wherein the thermo-degradable material is one of the thermo-degradable polymers including: polypropylene carbonate (PPC), polyethylene carbonate (PEC) or other suitable thermo-degradable polymer.

10. An RF integrated circuit or an RF amplifier included in a package formed in accordance with the method of claim 9 , the RF integrated circuit or the RF amplifier comprising:

the at least one die on a substrate;

for each die, at least a bond-wire connected from the die to at least one terminal pad attached to the package; and

the air cavity formed around the at least one die and the bond-wire by the decomposing of thermo-degradable material.

11. An RF integrated circuit or an RF amplifier included in a package formed in accordance with the method of claim 8 , the RF integrated circuit or the RF amplifier comprising:

the at least one die on a substrate;

for each die, at least a bond-wire connected from the die to at least one terminal pad attached to the package; and

the air cavity formed around the at least one die and the bond-wire by the decomposing of the thermo-degradable material.

12. A method for packaging an integrated circuit as claimed in claim 1 wherein the thermo-degradable material has a dielectric constant substantially different than 1 and is molded onto the substrate, the at least one die and the bond-wires.

13. An RF integrated circuit or an RF amplifier included in a package formed in accordance with the method of claim 12 , the RF integrated circuit or the RF amplifier comprising:

the at least one die on a substrate;

for each die, at least a bond-wire connected from the die to at least one terminal pad attached to the package; and

the air cavity formed around the at least one die and the bond-wire by the decomposing of the thermo-degradable material.

14. An RF integrated circuit or an RF amplifier included in a package formed in accordance with the method of claim 1 , the RF integrated circuit or the RF amplifier comprising:

the at least one die on a substrate;

for each of the at least one die, at least a bond-wire connected to at least one terminal pad attached to the package; and

the air cavity formed around the at least one die and the bond-wire by the decomposing of the thermo-degradable material.

15. An RF integrated circuit or an RF amplifier as claimed in claim 14 , wherein the air cavity has a height of at least 200 micro-meters.

16. The method of claim 1 , wherein decomposing the thermo-degradable material includes heating the thermo-degradable material to generate a gas and a solvent in the cavity.

17. The method of claim 1 , wherein the cavity is an air cavity and further including forming the air cavity and thermally decomposing the thermo-degradable material into a gas and permeating the gas through the encapsulant material.

18. An RF circuit package comprising:

a die on a substrate;

at least one bond-wire that connects the die to a terminal pad attached to the package;

a thermo-degradable material formed in contact with and around both the die and the at least one bond-wire; and

an encapsulant material that encapsulates and seals the thermo-degradable material, the die, and the bond-wires against the substrate,

the thermo-degradable material being configured and arranged with the encapsulant material to form an air cavity by transitioning into a gas in response to temperature treatment of the RF circuit package, and permeating the gas through the encapsulant material, the air cavity exposing portions of the die and the bond wires having been in contact with the thermo-degradable material via the transitioning of the thermo-degradable material into the gas.

19. A method for packaging an integrated circuit (IC) comprising steps of:

attaching a die on a substrate;

attaching bond-wires from the die to package terminal pads;

providing a thermo-degradable material in contact with the substrate, die and bond-wires;

molding an encapsulant material that encapsulates and seals the thermo-degradable material, the die, and the bond-wires against the substrate; and

forming an air cavity between the encapsulant material and the die by thermally decomposing the thermo-degradable material into a gas and permeating the gas through the encapsulant material, the air cavity exposing portions of the die and the bond wires having been in contact with the thermo-degradable material via the decomposing of the thermo-degradable material into the gas.

Assignments (13)