Fabrication of Functionally Graded Diamond/Al Composites by Liquid-Solid Separation Technology.

Hongyu Zhou,Wenyue Zheng,Junyou Liu,Minrui Ran,Zhi Tong,Huimin Wang,Yaqiang Li,Weidong Zhang

doi:10.3390/ma14123205

Abstract

The electronic packaging shell, the necessary material for hermetic packaging of large microelectronic device chips, is made by mechanical processing of a uniform block. However, the property variety requirements at different positions of the shell due to the performance have not been solved. An independently developed liquid–solid separation technology is applied to fabricate the diamond/Al composites with a graded distribution of diamond particles. The diamond content decreases along a gradient from the bottom of the shell, which houses the chips, to the top of the shell wall, which is welded with the cover plate. The bottom of the shell has a thermal conductivity (TC) of 169 W/mK, coefficient of thermal expansion (CTE) of 11.0 × 10−6/K, bending strength of 88 MPa, and diamond content of 48 vol.%. The top of the shell has a TC of 108 W/mK, CTE of 19.3 × 10−6/K, bending strength of 175 MPa, and diamond content of 15 vol.%, which solves the special requirements of different parts of the shell and helps to improve the thermal stability of packaging components. Moreover, the interfacial characteristics are also investigated. This work provides a promising approach for the preparation of packaging shells by near-net shape forming.

Highlights

The continuous development of microelectronic systems has resulted in the highly compact size of electronic devices and the dramatic increase in power density, which requires advanced thermal management material, housing the chip, to ensure efficient heat dissipation [1,2]
Diamond/Al composites have been studied extensively due to their excellent thermal conductivity (TC), tailorable coefficient of thermal expansion (CTE), and low density [3,4]
It is significant in guiding the industrialization and popularization of these types of materials, such as diamond/Cu composites and diamond/Ag composites, by analyzing the graded distribution of the microstructure and properties of diamond/Al composites

Summary

Introduction

The continuous development of microelectronic systems has resulted in the highly compact size of electronic devices and the dramatic increase in power density, which requires advanced thermal management material, housing the chip, to ensure efficient heat dissipation [1,2]. The part of the housing chip should have a low CTE to match the chip, while the part of the top packaging wall should have a high solderability to ensure brazing with the packaging cover plate [5]. The packaging shell is made by mechanical processing of a uniform block, but the different performance requirements have not been solved. Compared with the single or monotonous material, the functionally graded materials (FGMs) possess properties that enable the reduction in the thermal stress concentration [6]

Methods

Results

Conclusion