W-Cu and Cu Heat Sinks Made by Powder Injection Molding Process

• Main Authors: Yang Chih-Kuei, 楊智貴
• Other Authors: Hwang Kuen-Shyang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/14534699237148749598

碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 91 === The recent development on computers is heavily focused on the thermal management due to the high heat generated by the powerful IC. To improve the heat dissipation capability, heat sink modules have been used widely, particularly the ones with cooling fins. The current fins are made of copper and are either brazed or mechanically locked to the copper base. This type of joint, however, has high thermal resistance and deteriorate the thermal performance. The objective of this study was thus to make monolithic heat sinks that combines the base ad the fins by the metal injection molding process. Mechanically alloyed W-15Cu was prepared by using attritor. The milled powder, however, is too reactive. It usually self-combusts in air at room temperature. This powder, though provides a good combination on the thermal expansion match with the chip and good thermal conductivity, was thus not considered for MIM applications. Pure copper powder with adequate design on the binder system can be injection molded successfully. The thinnest fin made in this study was 0.4mm thick and 5mm high, an aspect ratio of 12.5. However, the molding parameters and mold design has to be adjusted correctly.