----- Original Message ----- From: "Bob Jones" <[EMAIL PROTECTED]> To: "Protel EDA Forum" <[EMAIL PROTECTED]> Sent: Friday, March 15, 2002 11:43 AM Subject: Re: [PEDA] Limitations on InternalPlane layers
> > ----- Original Message ----- > From: <[EMAIL PROTECTED]> > To: "Protel EDA Forum" <[EMAIL PROTECTED]> > Sent: Friday, March 15, 2002 9:34 AM > Subject: [PEDA] Limitations on InternalPlane layers > > > > > I'm still on my first PCB under P99SE. I need to add quite a few extra > routes, > > but the PCB is really dense. Can I route these on the InternalPlane > layers? > > I've done this on occasion. It's a bit tricky, but if you have no other > routing options and don't want to add layers it can be done. > > > Should I have used Polygon pours on ordinary layers instead? > > I've used the internal layer as is. > > > If I am allowed to use the plane layers, then how can I tell whether I'm > going to isolate some > > connections from others and how can I clean up where the trace ploughing > would > > leave nasty slices / lost copper? > > When I've done this I've used a midlayer to route the connections that I > needed. The tricky part is to keep an eye on the internal layer that you > will be merging these on. You'll want to make sure you don't block off your > VCC or GND hits to the plane. In my case I tried to route along the edge of > the pcb. > I only needed to add 3 traces to my internals, so you may have a more > difficult time. I added (3) 8 mil traces on a mid layer and then copied them > and pasted them onto my internal layer were I made them 24 mils to keep a > clearance between them and the plane. This is anti-area because of the > positive-negative issues with internals. The internal is negative and the > mid layer is positive. When the internal becomes positive the 24 mil traces > will accommodate the 8 mil traces nicely! > Then you can make composites, depending on your Cam package to let the > fabricator know that these will be merged. Maybe an explanation will help > them also. > I hope I was able to explain this. It was a lot easier for me when I'm > looking on screen at my job. If you need to you can call me. > > >Also on plane layers can I pull the plane > > completely away from a particular area? > > I've had instances where a pcb is say 12" long and I've removed 6" of the > plane. I was unsure if this was appropriate but I didn't hear anything from > the fabricator. Other companies have asked me to add various islands of > copper to control the "evenness" of the pcb stackup. > > >And finally, if I use a polygon on a > > normal layer, then how do I create the thermal relief's? > > I didn't go with this method, but it should pour them the way you want in > the setup for polygons. You may need to look into the rules to adjust them > further. > > > > > > > Bob Jones > Digitized Technologies > 2 Summit Road > P.O.Box 7284 > Prospect, CT. 06712-1541 > Tel: 203-758-6312 > Fax: 203-758-3338 > email: [EMAIL PROTECTED] > [EMAIL PROTECTED] > > Notice: This message is intended solely for the person to whom it > is addressed. Unintended recipients will be legally responsible for > unauthorized use, disclosure, copying or distribution. If you have > received this message in error, please notify the sender immediately > by replying to this message. Then delete this message from your > system. Thank you. > > > Kiernan Fitzpatrick > > > > ------------------------------------------------- > > Join IrishCircle - IrishAbroad's premium service > > http://www.irishabroad.com/circle/ > > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
