Nanobond® assembly – a rapid, room temperature soldering process

Reactive nanotechnologies (RNT) has commercialized a new technology that will revolutionize how manufacturers join components using solder materials. (See Figure 1) The joining process is based on the use of reactive multilayer foils as local heat sources. The foils are a new class of nano-engineered materials, in which self-propagating exothermic reactions can be ignited at room temperature through an ignition process. By inserting a multilayer foil between two solder layers and two components, heat generated by the reaction in the foil melts the solder and consequently bonds the components. The joining process can be completed at room temperature in air, argon or vacuum in approximately one second. The resulting metallic joints exhibit thermal conductivities two orders of magnitude higher, and thermal resistivities an order of magnitude lower, than current commercial TIMs. The use of reactive foils as a local heat source eliminates the need for torches, furnaces, or lasers, speeds the soldering processes, and dramatically reduces the total heat that is needed. Thus, temperature-sensitive or small components can be joined without thermal damage or excessive heating. In addition, mismatches in thermal contraction on cooling can be avoided because components see very small increases in temperature. This is particularly beneficial for joining metals to ceramics. The fabrication and characterization of the reactive foils is described, and the value proposition for nanobonding is presented. This paper also shows the applicability of this platform technology to many areas of packaging including thermal interface materials, microelectronics, optoelectronics, and light emitting diodes (LEDs).