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- Newsgroups: comp.sys.ibm.pc.hardware
- Path: sparky!uunet!spool.mu.edu!torn!nott!bnrgate!bmers95!bnr.ca!khor
- From: khor@bnr.ca (Kyle Hor)
- Subject: Re: What's the deal? My chip says "SX-25"; Norton says "SX-33"
- Message-ID: <1993Jan5.151627.9623@bmers95.bnr.ca>
- Sender: usenet@bmers95.bnr.ca
- Reply-To: khor@bnr.ca
- Organization: Bell-Northern Research Ltd.
- References: <C01LuI.542@news.cso.uiuc.edu> <sheldon.725671411@pv141b.vincent.iastate.edu> <1992Dec30.233238.14371@ptdcs2.intel.com> <C0CoGq.1ww@usenet.ucs.indiana.edu>
- Date: Tue, 5 Jan 1993 15:16:27 GMT
- Lines: 41
-
- In article <C0CoGq.1ww@usenet.ucs.indiana.edu>, ntaib@silver.ucs.indiana.edu (Iskandar Taib) writes:
- |> In article <1992Dec30.233238.14371@ptdcs2.intel.com> ssivakum@ptdcs2.intel.com (Sam Sivakumar) writes:
- |>
- |> > I work in lithography R&D, so I am not intimately familiar with the
- |> >sort and test world, but I know that every chip sold is tested. Usually,
- |> >once the lot of wafers leaves the fabrication line, every chip on each wafer
- |> >is tested for functionality as function of voltage and speed. There may be
- |> >other tests done at this stage as well, like transistor characteristics, etc.
- |> >and maybe others that I am not aware of. All chips that do not work are
- |> >inked, so when the wafer is diced into individual chips, the inked fellas are
- |> >rejected summarily.
- |>
- I agree 100%. This is how it is done. BTW, there are 3 main
- category of tests for digital ICs.
-
- functional : mainly boolean logics
- DC : voltage & current levels
- AC : switching speed
-
- At the wafer stage, only simple functional tests are performed as the DC and AC
- characteristics could change due to the processes further down the line.
-
- |> Hmmm
- |>
- |> Anyone know where one could write to get rejects like this? 'Twould
- |> be a nice conversation piece...
- |>
- |> Perhaps they wouldn't give away the latest 486-66/DX2 but surely there
- |> are old 286 wafers lying around somewhere..
- |>
- I dunno what they do with the wafers, but they are unsightly. Good dice
- are taken out to be assembled as IC's and the remaining bad dice scattered
- across the wafer are all inked anyway.
-
- ............................................................................
- . Kyle Hor . / / _ . Email khor@bnr.ca .
- . Bell-Northern Research Ltd. . /__\ / / /_\ . Phone (613) 763-2488 .
- . Ottawa, Ontario, Canada . / \ \/ / \__ . ESN 393-2488 .
- ....................................__/.....................................
- ................ standard disclaimer, 2 cents opinion ....................
- ............. searching forever, for the perfect solution ................
-