Browse Prior Art Database

LOW COST POWER QFN PACKAGING CONCEPT (LC PQFN)

IP.com Disclosure Number: IPCOM000012104D
Original Publication Date: 2003-Apr-08
Included in the Prior Art Database: 2003-Apr-08
Document File: 3 page(s) / 178K

Publishing Venue

Motorola

Related People

Lan Chu TAN: AUTHOR [+4]

Abstract

Existing Power QFN (PQFN) packages are assembled using heavy 5, 10, 15, 20 mils Al wires. Such heavy wires requires a heavy wedge bonding process, which has low throughput and high cost. In this paper we present a PQFN in which the heavy Al wires have been replaced with two 4 or 5 mils diameter Cu wires. Together with a thermally conductive mold compound, the new PQFN performs as well thermally as existing packages. Through thermal performance simulation, we have determined that the Theta JA’s for the new package are comparable to that of the existing package. The new packaging recipe has a much lower cost because only a single wirebonding platform is required and throughput is increased.

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LOW COST� POWER QFN PACKAGING CONCEPT

( LC PQFN)

Lan Chu TAN, Cheng Choi YONG, Ruzaini IBRAHIM, Azhar ARIPIN

ABSTRACT

Existing Power QFN (PQFN) packages are assembled using heavy 5, 10, 15, 20 mils Al wires.� Such heavy wires requires a heavy wedge bonding process, which has low throughput and high cost.� In this paper we present a PQFN in which the heavy Al wires have been replaced with two 4 or 5 mils diameter Cu wires.� Together with a thermally conductive mold compound, the new PQFN performs as well thermally as existing packages.� Through thermal performance simulation, we have determined that the Theta JA’s for the new package are comparable to that of the existing package.The new packaging recipe has a much lower cost because only a single wirebonding platform is required and throughput is increased.�

BACKGROUND

Power QFN packages commonly are used in automotive applications.� Current Power QFN (PQFN) packages are assembled using heavy 5, 10, 15, and 20 mils Al wire.� The use of such large wires requires a heavy wedge bonding process, which has a negative impact on throughput and increases production cost because two different wirebond platforms are needed.� Alternative solutions have been sought to provide a lower cost option for PQFN packages.

DESCRIPTION

This new application uses a ball bonder with the capability to bond heavy copper wires.� We use two 4 or 5 mils copper wires instead of the single 15 or 20 mils Aluminum wire presently used.� The new applicatio...