Copper-Based Conductive Composites with Tailored Thermal Expansion
Copper-Based Conductive Composites with Tailored Thermal Expansion
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DOI：
10.1021/am403227c
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发表时间：
2013-11-13
影响因子：
9.5
通讯作者：
Dunn, Bruce
中科院分区：
文献类型：
--
作者：
Della Gaspera, Enrico;Tucker, Ryan;Dunn, Bruce
我们设计了一种中温热压工艺制备热膨胀可调的金属基复合材料。系数与高导电性和导热性的组合。该复合材料是基于将ZrW 2 O 8，一种具有负热膨胀系数（CTE）的材料，在连续的铜基体。ZrW 2 O 8使我们能够以可预测的方式调整CTE，而铜相负责导电和导热性能。在这些材料的加工中的一个重要考虑是避免ZrW 2 O 8相的分解。这是通过使用相对温和的热压条件（500 ℃、40 MPa、1 h）来实现的。为了确保这些条件能够烧结的铜，我们开发了一种合成路线，用于制备铜纳米颗粒（NP）的基础上减少常见的铜盐在水溶液中的存在下的尺寸控制剂。在500摄氏度下热压这些纳米颗粒后，我们能够实现铜的理论密度的92-93%。所得到的材料表现出CTE，其可以在纯铜的值（16.5ppm/摄氏度）和小于1 ppm/摄氏度之间调节。因此，通过调节两种组分的相对量，可以设计复合材料的性质，使得可以获得具有高电导率和与半导体或热电材料的相对低CTE值匹配的CTE的材料。这种独特的电和热性能组合使这些铜基金属基质复合材料能够用作各种半导体和热电器件的电触点，这些器件在热循环条件下提供稳定的操作。
We have devised a moderate temperature hot-pressing route for preparing metal matrix composites which possess tunable thermal expansion. coefficients in combination with high electrical and thermal conductivities. The composites are based on incorporating ZrW2O8, a material with a negative coefficient of thermal expansion (CTE), within a continuous copper matrix. The ZrW2O8 enables us to tune the CTE in a predictable manner, while the copper phase is responsible for the electrical and thermal conductivity properties. An important consideration in the processing of these materials is to avoid the decomposition of the ZrW2O8 phase. This is accomplished by using relatively mild hot-pressing conditions of 500 degrees C for 1 h at 40 MPa. To ensure that these conditions enable sintering of the copper, we developed a synthesis route for the preparation of Cu nanoparticles (NPs) based on the reduction of a common copper salt in aqueous solution in the presence of a size control agent. Upon hot pressing these nanoparticles at 500 degrees C, we are able to achieve 92-93% of the theoretical density of copper. The resulting materials exhibit a CTE which can be tuned between the value of pure copper (16.5 ppm/degrees C) and less than 1 ppm/degrees C. Thus, by adjusting the relative amount of the two components, the properties of the composite can be designed so that a material with high electrical conductivity and a CTE that matches the relatively low CTE values of semiconductor or thermoelectric materials can be achieved. This unique combination of electrical and thermal properties enables these Cu-based metal matrix composites to be used as electrical contacts to a variety of semiconductor and thermoelectric devices which offer stable operation under thermal cycling conditions.