Love-Hounds-request@GAFFA.MIT.EDU (09/19/89)
Really-From: "Andy Gough, x4-2906, pager 513, CH2-59" <AGOUGH%FAB6@sc.intel.com> >Date: Fri, 15 Sep 89 11:40:28 -0400 (EDT) >From: Alan William Hensel <ah1s+@andrew.cmu.edu> >Subject: Re: 3" CD > > >8 cm, exactly. > >And those 5-inches, they're 12 cm, exactly. > >Go metric. > >-al+ Nothing is exact. Every process has natural variation that you cannot control. So those CD's are specified with a +/- variation in the diameter--it could only be a few microns, but it is there. You can use statistics to study the natural variation in your process and insure that you don't fail your specification very often. Go statistical. -andy