Basic knowledge of target binding

1、 What is binding? Binding refers to welding the target and back target with solder. There are three main ways: crimping, brazing and conductive adhesive. Target binding is commonly used for brazing, while brazing filler metals are commonly used for in, Sn, in – SN. In general, when soft brazing filler metals are used, sputtering power is required to be less than 20W / cm2.

2、 Why is it necessary to bind

1? To prevent the target from uneven fragmentation due to heat, such as ITO, SiO2, ceramics and other brittle targets and sintered targets;

2. To save cost and prevent deformation, if the target is too expensive, make the target thinner and bind the back target to prevent deformation.

3、 The choice of back target

1. Common oxygen free copper has good conductivity, and the thermal conductivity of oxygen free copper is better than that of copper;

2. The thickness of back target is moderate, and the thickness of back target is generally recommended to be about 3mm. Too thick, consuming part of the magnetic strength; too thin, easy to deformation.

4、 Binding process

1. Pretreatment of the target and back target surface before binding

2. Place the target and back target on the soldering table, raise the temperature to binding temperature

3. Metallize the target and back target

4. Bonding target and back target

5. Cooling and post-treatment

5. Precautions for binding target

1. Sputtering temperature should not be too high

2. Increase the current slowly

3. Circulating cooling water should be lower than 35 ℃ Degree

4, suitable target density

6, reasons for back target falling off

1, high sputtering temperature, back target easy to be oxidized and warped, target will crack during high temperature sputtering, resulting in back target falling off;

2, too large current, too fast heat conduction, resulting in too high temperature, melting of solder, resulting in uneven solder, resulting in back target falling off;

3, temperature of circulating cooling water outlet should be lower than 35 ℃

4. The density of the target material itself is very high. When the density of the target material is very high, it is not easy to absorb, there is no gap, and the back target is easy to fall off. A kind of