On Fri, 11 Jan 2002 at 12:09:27, Norman Dunbar wrote: (ref: <[EMAIL PROTECTED]>)
>Thanks for that simple explanation Jerome. > >Does that mean that a 4 layer board is really 2 * two layers plus an >insulator between and then when each pair of layers has been etched, the >board is 'glued' together? I mean, it would be difficult to etch out the >tracks in the middle two layesr otherwise :o) Exactly. The vias (connections between layers) need special treatment. Nasta can probably explain. These are done with 2 layers by immersing board in molten solder. I suspect multi-layers are done in a similar way. However the via layout can be very complex - ie vias between inner layers. >-----Original Message----- >From: Jerome Grimbert [mailto:[EMAIL PROTECTED]] >Sent: Friday, January 11, 2002 12:04 PM >To: [EMAIL PROTECTED] >Subject: Re: [ql-users] Q40/Q60/??? Ultra IO card > > >Well, you can also have track inside ! >Think of the board as a sandwich. >There is two side per slice of bread. > >Therefore, you can have the simple sandwich: 1 slice of bread, 2 layers. >There is also a sandwich with 2 slice of bread (separated by your favorite >ham): 4 layers. >Things like big-mac, with 3 slice of bread: 6 layers! >and so on. >Of course, the more layers, the more expensive to manufacture!!! >Therefore, a manual routing with 4 layers is far better than >autorouting with 6 layers! >This email is intended only for the use of the addressees named above and >may be confidential or legally privileged. If you are not an addressee you >must not read it and must not use any information contained in it, nor copy >it, nor inform any person other than Lynx Financial Systems or the >addressees of its existence or contents. If you have received this email >and are not a named addressee, please delete it and notify the Lynx >Financial Systems IT Department on 0113 2892990. -- QBBS (QL fido BBS 2:257/67) +44(0)1442-828255 mailto:[EMAIL PROTECTED] http://www.firshman.demon.co.uk Voice: +44(0)1442-828254 Fax: +44(0)1442-828255 TF Services, 29 Longfield Road, TRING, Herts, HP23 4DG
