The demand for thermal management in electronic packaging (EP) and its allied industries, especially in high-power electronics, has grown in the last three decades due to the continuous miniaturization of electronic components. The thermal management of EP warrants metal/alloys/composite with uniquely low thermal expansion and high thermal conductivity. Controlled expansion (CE) materials play a significant role and impart tunable thermal properties. The first and second generations of CE alloys, like Invar, Kovar, and Elinvar, are unsuitable to provide high thermal conductivity for heat sinking along with low density, which are essential for EP materials. The third-generation hypereutectic Al-Si alloys overcome these limitations. The capability to tune the CTE values of the Al-Si CE alloys combined with their lower densities and high thermal conductivities has made them a preferred choice for electronic applications, such as carriers and heat sinks. However, poor machinability and the inability to prepare geometrically complex Al-Si CE alloy with conventional manufacturing processes pose challenges. A paradigm shift is taking place in fabricating components through additive manufacturing and friction stir processing, assisting in mitigating machining and shape complexity. The present work attempts to provide comprehensive details on the properties, microstructures, and processing techniques of hypereutectic Al-Si CE alloys and recent advancements.

中文翻译：

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用于电子封装应用的铝硅控制膨胀合金

由于电子元件的不断小型化，电子封装 (EP) 及其相关行业（尤其是高功率电子产品）对热管理的需求在过去三十年中不断增长。 EP 的热管理保证金属/合金/复合材料具有独特的低热膨胀性和高导热性。受控膨胀 (CE) 材料发挥着重要作用，并赋予可调节的热性能。第一代和第二代 CE 合金，如 Invar、Kovar 和 Elinvar，不适合提供用于散热的高导热性和低密度，而这对于 EP 材料至关重要。第三代过共晶铝硅合金克服了这些限制。 Al-Si CE 合金具有调节 CTE 值的能力，加上其较低的密度和高导热率，使其成为载体和散热器等电子应用的首选。然而，机械加工性差以及无法用传统制造工艺制备几何形状复杂的 Al-Si CE 合金带来了挑战。通过增材制造和搅拌摩擦加工制造部件正在发生范式转变，有助于减轻加工和形状复杂性。目前的工作试图提供有关过共晶 Al-Si CE 合金的性能、微观结构和加工技术以及最新进展的全面详细信息。