RE: [SI-LIST] :PCB Bd thkness'

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From: Scott Brenneman (sbrenneman@ideo.com)
Date: Tue Mar 07 2000 - 15:09:59 PST


My understanding is that 1/16" was the thickness of one ply of plywood, and
that the original PCB lamination machines were based on plywood laminators.

Scott

-----Original Message-----
From: owner-si-list@silab.eng.sun.com
[mailto:owner-si-list@silab.eng.sun.com]On Behalf Of Scott McMorrow
Sent: Tuesday, March 07, 2000 2:35 PM
To: si-list@silab.eng.sun.com
Subject: Re: [SI-LIST] :PCB Bd thkness'

I believe that these numbers were written by the
"Ancient Ones" on stone tablets. Unfortunately, an
irate member of the "Manufacturing Clan" was a bit peeved
at the members of the "Design Clan" and shattered those tablets
in pieces after a fit of disgust. The original intentions of the
"Ancient Ones" have been lost to history and mythology, however,
ever since that day an eternal clan war has raged.

regards,

scott

--
Scott McMorrow
Principal Engineer
SiQual, Signal Quality Engineering
18735 SW Boones Ferry Road
Tualatin, OR  97062-3090
(503) 885-1231
http://www.siqual.com

Dave Hoover wrote:

> I always thought the .062", .093", .125" was for through hole leads, > press fit connector length, and edge card connectors. Standardize > for consistancy and repeatability. That's what I was taught..... > > Dave > -----Original Message----- > From: Abd ul-Rahman Lomax [mailto:marjan@vom.com] > Sent: Tuesday, March 07, 2000 12:59 PM > To: si-list@silab.eng.sun.com > Subject: Re: [SI-LIST] : different 4-layer board Stack up (S-P-G-S) ? > > At 11:14 AM 3/7/00 -0700, ajmani@us.ibm.com wrote: > > >By the way, can someone enlighten me on how 0.062" came to be the standard > >board thickness. > > I haven't seen any documentation, but the reason is fairly obvious. 1/8 > inch was thicker than necessary for most applications and 1/32 inch was too > thin, so 1/16 was chosen. .031 and .125 are still standard core > thicknesses, along with 3/32, 0.093. We see the same history in 1/2 ounce, > 1 ounce, and 2 ounce copper foil. > > marjan@vom.com > Abdulrahman Lomax > P.O. Box 690 > El Verano, CA 95433 > > **** To unsubscribe from si-list or si-list-digest: send e-mail to > majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE si-list > or UNSUBSCRIBE si-list-digest, for more help, put HELP. > si-list archives are accessible at http://www.qsl.net/wb6tpu > **** > > **** To unsubscribe from si-list or si-list-digest: send e-mail to majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP. > si-list archives are accessible at http://www.qsl.net/wb6tpu > ****

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