Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!lll-crg!caip!cbmvax!grr From: grr@cbmvax.cbm.UUCP (George Robbins) Newsgroups: net.micro.amiga Subject: Re: Four-layer PC Boards Message-ID: <683@cbmvax.cbmvax.cbm.UUCP> Date: Sun, 31-Aug-86 19:38:07 EDT Article-I.D.: cbmvax.683 Posted: Sun Aug 31 19:38:07 1986 Date-Received: Mon, 1-Sep-86 02:42:28 EDT References: <1653@well.UUCP> <1655@well.UUCP> Reply-To: grr@cbmvax.UUCP (George Robbins) Distribution: net.micro.amiga Organization: Commodore Technology, West Chester, PA Lines: 43 Keywords: In article <1655@well.UUCP> perry@well.UUCP (Perry S. Kivolowitz) writes: > >You said yourself that you, because you are a conscientious engineer, would >spend a lot of time with a board layout person if your were producing a two >layer board but would need to spend less time overseeing the layout person >if you were producing a four layer board. > >Well, you'd spend the extra time, Steve, but others may not. I can't vouch >for all manufacturer's of Amiga expansion hardware but it is clear that some >people do not share the same commitment to quality as you (and I) have. > >Hey, when you care enough to send the very best...you'll go the extra distance >to produce a four layer board. > >Perry S. Kivolowitz Perry, this is still a bit misleading... An engineer desigining a PC board will use a multi-layer board because he feels that he has to, not because it yields some ineffably better product. 4 layer Benefits: automatic 'good' power and ground distibution simplified signal routing lower signal noise levels lower radiated noise levels (FCC!) more likely to work well on the first try more likely to pass FCC on the first try 4 layer Detriments: higher artwork and setup charges higher board cost (1.5-3 X) The real kicker is that the multi-layer board in the prototype or early production unit you look at is likely to be quietly replaced by a garden variety double-sided board if the vendor makes it into volume production. That extra cost of materials translates into either decreased profit margin or a non-competitive price. These are of course business world no-no's. -- George Robbins - now working with, uucp: {ihnp4|seismo|caip}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@seismo.css.GOV Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)