How Can Millions of Aligned Graphene Layers Cool High Power Microelectronics?

Abstract

Thermal management is an increasingly critical problem in today's microelectronics industry. As power requirements increase and size requirements decrease, innovative materials with high thermal conductivity (TC), light weight, and many times low coefficient of thermal expansion (CTE) are desired to solve these thermal challenges. Thermal Pyrolytic Graphite (TPG*), a unique synthetic material produced by Momentive via chemical vapor deposition, contains millions of layers with highly-oriented stacked graphene planes and exhibits excellent in-plane thermal conductivity (>1500 W/m-K) and very low density (2.25g/cm3). In order to take advantage of its superior properties for thermal management, various forms of TPG-metal composite products were developed in the past few years. TPG composite with metal encapsulation simultaneously achieves high thermal conductivity from the TPG core and high mechanical strength from the metal shell. Momentive's proprietary bonding technology enables an intimate and strong joint between TPG and dissimilar metals, including Al, Cu, Sn, WCu, MoCu, AlSiC, and AlBe. In addition, the variety of compatible metals adds new functionalities to the TPG composite, such as platability and solderability for direct die attachment, CTE matching to semiconductor, and flexibility for off-plane connectivity. Also in this paper, three TPG composite categories, i.e.: TC1050* Heat Spreader, TPG Heat Sink and TPG Laminate, will be discussed in detail. Individually, their design guidance, performance, reliability, and application examples will be shared with the reader. With these three TPG composite products, Momentive has translated our extensive experience and success in thermal management at the system level, with TC1050 Heat Spreaders, to the device level, with TPG Heat Sinks and TPG Laminates.