AVS 49th International Symposium
    Vacuum Technology Wednesday Sessions
       Session VT-WeA

Paper VT-WeA8
Soft LaserBellows

Wednesday, November 6, 2002, 4:20 pm, Room C-104

Session: Vacuum Measurements, Components, and Control
Presenter: D.U. Chang, LaserTech USA
Correspondent: Click to Email

New and innovative welding technology brought precision, high quality "soft" metal bellows to practical reality. Thin gage annular disks are laser welded automatically with the aid of computer-controlled precision guidance by a machine vision seam tracking system. The resistance to the axial motion of the bellows (spring rate) is reduced to 47% to 19% compared with conventional bellows of the same size. These "soft" bellows are especially suitable for hermetic sealing of vacuum valves and manipulators for ultra-high vacuum and semi-conductor applications. Higher positioning accuracy and low motor power are some of the benefits of these bellows. The "soft" bellows are 100% checked for weld integrity by automatic welding/inspection machines, followed by mass spectrometer leak check. Randomly selected samples go through life cycle testing. The bellows last more than 5 million cycles without failure. Finite element analysis (FEA) of the bellows was used extensively in the design of bellows. Comprehensive life cycle testing and leak testing verified the analytical prediction.