Going single sided is for 1 reason and that's cost reduction. FR4 is typically more then twice the cost of Phenolic, not 50% higher. Proper circuit and layout analysis must be considered before you even think of going single sided. EMC and the number of jumpers required to route the board will often give you a good indication on the feasibility of doing it single sided. There's no point if a 1 layer board will require twice the area or require so many jumpers the cost of inserting those jumpers and the total number of drill holes equal a double sided board. Some feasibility guidelines i use: .How fast and noisy is the circuit. .Will the layout fit into the maximum allowable outline. .Type of board, carbon ink, silver thru hole or no ink. .Is the minimum drill size 0.60mm or greater. .Will there be a significant reduction of drill holes. .How many thru hole components need to be mounted opposite the SMT side. .How much cost reduction will i really get. A well designed 1 layer board will give me better yield then a double sided board. With proper hole sizing, annular ring, use of elongated pads and teardrops the problems you mentioned will only occur with improperly mounted thru hole parts or during rework. The cost reduction can be very significant for the right product. You need to know what you're getting into and factor in the layout costs which is usually 2.5 to 4 times more. Cheers Terry Heng Design Consultant T3DESIGN Innovative Product Development Thinking out of the box. At 12:10 AM 7/31/01 -0500, you wrote: >The real cost of single sided PCBs is that they are usually larger for a >given circuit. > >Suppose you have a circuit that you can put in a 2" x 1" format with double >sided. That's 2 in**2. If I have to make it 2" x 2" to accommodate single >side routing, the board area goes to 4 in**2. > >So if a double sided board is 50% more expensive than a single sided board, >you are still losing money. Say the 1 sided board is $0.10/in**2 and the >double sided is $0.15/in**2. The boards mentioned would cost $0.30 and >$0.40! > >Of course, if you can punch cheap phenolic, that's fine but that is >typically much higher tooling costs. And, if you want to do them yourself, >single sided is the way to go. > >Awhile back I read that single sided boards are not as reliable as double >sided because the plated through holes anchor the copper better against >things like cracks, vibration, etc. So that's something else to consider. > >Regards, > > >Al Williams >AWC >* Floating point A/D: http://www.al-williams.com/awce/pak9.htm > >-- >http://www.piclist.com hint: PICList Posts must start with ONE topic: >[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads