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Method for a die-down flip-chip package design

IP.com Disclosure Number: IPCOM000007142D
Publication Date: 2002-Feb-27
Document File: 3 page(s) / 68K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a die-down flip-chip package design. Benefits include improved thermal performance.

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Method for a die-down flip-chip package design

Disclosed is a method for a die-down flip-chip package design. Benefits include improved thermal performance.

Background

   The power dissipation of the non-CPU devices (such as a chipset) on the motherboard keeps increasing. A cooling solution is typically needed to maintain the non-CPU devices below the maximum operating temperature.

    The conventional state of art is to mount a heatsink on the top of the non-CPU device to enhance cooling. However, the space required for a heatsink may be limited or interfered with by the CPU cooling solution. In addition, the direction and amount of airflow is typically not optimal for the non-CPU devices because the CPU is higher priority when the system airflow is designed.

              The Si die is mounted on the top of the package substrate with die bumps and underfill. The package is then surface mounted to the motherboard with solder balls. A heatsink is typically mounted on the top of the die to enhance cooling. Most of the heat generated by the die is dissipated to the ambient environment by the heatsink as shown by the path . The remaining heat is dissipated through the package substrate, solder ball, motherboard, and finally to the ambient as shown by the path .

General description

    The disclosed method is a flip-chip package design with the die mounted underneath the package substrate with die bumps and underfill. The heat generated by the Si die can be dissipated directly through the motherboard or through the chassis metal wall. The disclosed method is applicable to the chipset and the other low-power devices mounted on the motherboard.

              The key elements include a flip-chip package design with the die mounted underneath the package substrate with die bumps and underfill.

Advantages

              The disclosed design presents several advantages, including:

•             The method does not require heatsink space or airflow through the device.

•             The method fully utilizes...