A process for joining first and second aluminum sheets in which the bonding surfaces of the aluminum sheets have their aluminum oxide layer replaced by a zinc layer and the zinc layers are plated with a non-alloy metal bonding material such as cadmium. The first and second aluminum sheets are then assembled and fastened together with an engaging means for holding the sheets together, and then the assembled sheets are placed in a vacuum. The sheets are subsequently heated in the vacuum thereby creating a bond of cadmium between them, removed from the vacuum, and then passivated.
A tappet is used in an internal combustion engine. A cam-slidably-contacting member is placed on a top wall of a tappet body via diffusing material which comprises mixture of one or more elements of Zn, Mg, Sn, Cu and Pb. The cam-slidably-contacting member and the tappet body are pressed with the diffusing material held therebetween, so that the diffusing material is diffused into the tappet body and the cam-slidably-contacting member until a layer which comprises only the diffusing material does not substantially remain to form the tappet having high strength.
A method of interconnecting integrated circuit chips to a substrate during the assembly of a multi-chip module. Instead of forming an electrical and physical bond by reflowing solder bumps attached to the pads of the chips and the substrate, as in flip-chip bonding, thin pads of specially selected dissimilar metals placed on the chips and substrate are connected by a solid-state diffusion bonding process. In one embodiment, the I/O pads on a chip are formed from aluminum or an aluminum alloy and are aligned and placed into physical contact with corresponding metal pads or metal layered pads on a substrate, where the metal is capable of being diffusion bonded to aluminum. The combination of chip(s) and substrate are then heated in a controlled atmosphere at a temperature and for a time sufficient to cause solid-state diffusion bonding to occur.
A tappet is used in an internal combustion engine. A cam-slidably-contacting member is placed on a top wall of a tappet body via diffusing material that includes a mixture of one or more elements of Zn, Mg, Sn, Cu and Pb. The cam-slidably-contacting member and the tappet body are pressed with the diffusing material held therebetween, so that the diffusing material is diffused into the tappet body and the cam-slidably-contacting member until the layer of the diffusing material does not substantially remain, and a tappet of high strength is formed.
A sputtering target assembly is fabricated by diffusion bonding a target material plate to a backing plate. The plates are cleaned in a vacuum environment, and an interlayer is formed on one or more of the plates. The plates are then joined under heat and pressure, before an oxide layer can form on the joining surfaces of the plates. The plates may be sequentially processed through cleaning, interlayer deposition, and bonding chambers, all with vacuum environments, to form the finished part, or, a single chamber may be used to provide the cleaning, interlayer deposition and bonding functions.
