PROCESS OPTIMIZATION OF ION PLATING NICKEL-COPPER-SILVER THIN FILM DEPOSITION

摘要

Simulation of thin film nano deposition manufacturing processes can give insight into process behavior and promote efficient resource allocation. If the process involves feedback control, (ⅰ) one can study controllability and observability of the system, (ⅱ) know ahead of time what type of control scheme will be needed and (ⅲ) the size and type of mechanical hardware to specify. DC ion plating systems are a collection of individual control systems that are run in either open loop or feed forward as a process. Arc disturbances from contamination or high voltage isolation breakdown can change process pressure by as much as 5mTorr and concurrently result first in a plasma voltage decrease followed by a voltage increase for up to 5 sec using PID control. Properties of the film can be significantly altered compared with previous layers resulting in significantly different failure modes of the film when tested in rolling contact fatigue. Ansi T5 ball bearings are coated with approximately 10nm of nickel-copper followed by 110nm of silver using an ion plating process. An ultra high vacuum rolling contact fatigue test platform is introduced for solid lubrication testing. High voltage events shorten test life and introduce a unique failure mode when tested in rolling contact fatigue. Voltage and pressure changes result in significant thickness monitor measurement errors. A regulator control scheme that minimizes process pressure overshoot is simulated.