(1) Density, this is the most important, good target density of at least 97%, so we buy back the target can be calculated according to the weight volume of your target density and theoretical block density of how much, less than 90% of returns.
(2) Cracking problem, magnetic target is very easy to crack, so we must require the back of the copper plate, this is necessary, the other target material should not be too thick, less than 5mm the best. The metal target is not cracked by the assembly, otherwise its density must be very poor.
(3) conductivity, for Azo, Ito target, buy back can be measured their conductivity is how much, different companies use the powder different, conductivity has a great difference, the smaller you do out of the film conductivity of the better. Or you'll never get the resistivity you need.
Good azo target material azo powder is very important, the best is the use of pure azo powder, but the price is very expensive, and the process is more complex, the target material made out of the best membrane resistivity.
At present, the main use of ZnO and $literal powder mixed together, but the problem is that Al is very difficult to doping into the ZnO, so the resistivity is not good. Ito similar.
It is recommended that target materials not be done by themselves, or that they spend money on the targets of large companies. You are wasting your time on the other hand and you are far from the real good target, and your condition is completely out of the question.