Target bonding is a very important step in sputter coating, which extends the life of the target and improves the performance of the target. Target bonding, as its name suggests, is the welding of the sputtering target to the back target. Generally speaking, there are three main ways to achieve target bonding: crimping, brazing and conductive adhesives.

Methods

Crimp: In order to improve the contact quality, graphite paper, Pb or In leather are used.

Brazing: Generally, in the case of using a solder material, a sputtering power of less than 20 W/cm 2 is required, and In is commonly used.

Conductive adhesive: The conductive adhesive used should be resistant to high temperatures and have a thickness of 0.02-0.05 μm.

Application

Technically, targets with a flat surface and can be metallized can be bonded to improve the heat dissipation and target utilization of the sputtering process. It is suitable for brittle targets such as ITO, SiO2, ceramics, and sintered targets; soft metal targets such as tin and indium; and the case where the target is too thin and the target is too expensive.

Requirements of the Back Targets

The back target is generally selected from oxygen-free copper and molybdenum targets with a thickness of about 3 mm. It requires good electrical conductivity, sufficient strength, hollow or solid structure, and moderate thickness (2-3 mm or so, too thick, and consumes part of the magnetic strength; too thin, easily transformed).

Back target shedding

The back target shedding may be caused by the following reasons: the sputtering temperature is too high, so that the oxygen-free copper is oxidized and warped; the current is too large and the heat conduction is too fast, so that the temperature is high, under which condition the welding material is easily melted; the circulating water temperature is high, and the heat dissipation is not good; the density of the target itself is too high, so that the back target is not easily adsorbed.

Stanford Advanced Materials is devoted to machining standard backing plates and working together with the Taiwan Bonding Company for providing bonding services. For more information please visit https://www.sputtertargets.net/. For more questions about target bonding materials, methods and services, please see our listing of frequently asked questions (FAQs).