In the late 70s when you could actually get semiconductor companies to do specials, a friend of mine was taking DRAM chips, connecting to the sense amplifiers and using them as imagers. Tom Dagostino Teraspeed Consulting Group LLC 503-430-1065 tom@xxxxxxxxxxxxx www.teraspeed.com -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Christopher Jakubiec Sent: Tuesday, August 17, 2004 10:04 AM To: reanderson@xxxxxxxxxxxxx Cc: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: IC package Certainly during low current (leakage) wafer level testing that I have performed in the past, the effects of having the fluorescent lights on in the lab are real. The light does in fact excite electron-hole pairs that contribute to the current due to the photoeletric effect. -Chris Ray Anderson wrote: > Hal Murray wrote: > > >>>Black was also cheaper to make before, (remember mostly black and grey >>>plastics only) >>> >>> >> >>I assume the basic answer is cost. >> >>Clear plastic is available for LEDs and photo receptors - other >>colors/filters too. Anybody have an estimate as to how much more non-black >>costs? >> >> >> >> > > Another reason for black (or other photo opaque color) other than clear > is that ambient light shining on the die can have 'unintended > consequences' . I remember a couple cases a long time ago where in one > instance ambient light shining through the 'erase' window on an EPROM > somehow changed timing enough to crash a system (covering the window > with black tape restored normal functionality). In another case 120Hz > noise was modulated onto some driver outputs in a de-lidded chip we were > working on in the lab. Shielding the die from the ambient fluorescent > lighting made the 120Hz nose on the outputs go away. > > -Ray > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > List FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ > > List technical documents are available at: > http://www.si-list.org > > List archives are viewable at: > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu