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Reactive bonding describes a wafer bonding procedure using highly reactive nanoscale multilayer systems as an intermediate layer between the bonding substrates. The multilayer system consists of two alternating different thin metallic films. The self-propagating exothermic reaction within the multilayer system contributes the local heat to bond the solder films. Based on the limited temperature the substrate material is exposed, temperature-sensitive components and materials with different CTEs, i.e. metals, polymers and ceramics, can be used without thermal damage. == Overview == ] The bonding is based on reactive nano scale multilayers providing an internal heat source. These foils are combined with additional solder layers to achieve bonding. The heat that is required for the bonding is created by a self-propagating exothermic reaction of the multilayer system. This reaction is ignited by an energy pulse, i.e. temperature, mechanical pressure, electrical spark or laser pulse. The generated heat is localized to the bonding interface and limited due to a short term heating phase within milliseconds. This heat is an advantage of this approach, so the used materials are not exposed to high temperatures and allow rapid cooling.〔 A drawback is that this approach is not applicable for bond frame dimensions of few ten micrometres. This is based on the limited handling and structuring abilities of the foils at this small dimensions.〔 The material used for multilayer systems is a bilayer of alternating elements, commonly Ni/Al, Al/Ti or Ti/a-Si.〔 The metallic layer is usually 1 to 30 nm thick and can be arranged as horizontal or vertical nano scale material films and are a combination of a reactive and a low melting component.〔 With increased bilayer thickness, the reaction velocity decreases and the reaction heat increases. Therefore a specific balance between high reaction velocity and high reaction heat is necessary.〔 A commercial example of such material is NanoFoil. The corresponding bonding process is known as NanoBond. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「reactive bonding」の詳細全文を読む スポンサード リンク
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