X-Authentication-Warning: delorie.com: mail set sender to geda-help-bounces using -f X-Recipient: geda-help AT delorie DOT com Subject: Re: [geda-help] Four layer board To: geda-help AT delorie DOT com References: <8FC6735D-C5D6-4C0F-A645-ACB245937DCF AT ece DOT orst DOT edu> From: "Cam (camfarnell AT bitflipper DOT ca) [via geda-help AT delorie DOT com]" Message-ID: <5ab3242c-537c-0cc8-5578-5daf677cb39b@bitflipper.ca> Date: Thu, 2 Apr 2020 20:57:46 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <8FC6735D-C5D6-4C0F-A645-ACB245937DCF@ece.orst.edu> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - troi.cpanelboxes.net X-AntiAbuse: Original Domain - delorie.com X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - bitflipper.ca X-Get-Message-Sender-Via: troi.cpanelboxes.net: authenticated_id: camfarnell AT bitflipper DOT ca X-Authenticated-Sender: troi.cpanelboxes.net: camfarnell AT bitflipper DOT ca X-Source: X-Source-Args: X-Source-Dir: X-From-Rewrite: unmodified, already matched Reply-To: geda-help AT delorie DOT com Errors-To: nobody AT delorie DOT com X-Mailing-List: geda-help AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk Roger, Thanks for the encouragement. My board has a 44 pin SMT RAM chip on it. A lot of pins, close together going all over the place makes it a challenge to route. I'll continue to see if I can get it to work 2-layers but if not I've now been pointed to a good example of how to do a 4-layer board. Cheers Cam On 2020-04-02 7:24 p.m., Roger Traylor (traylor AT engr DOT orst DOT edu) [via geda-help AT delorie DOT com] wrote: > Cam, > > Just about finished with a new 2-layer board myself. I thought it probably could not > be done. It takes a few tries till you see the patterns of where signals need to go. I > started just making routes work with no DRC checking. Then I went back and > cleaned it up. I was surprised what I could do and how much room was left over. > It does take more time though. > > Before, I’ve done 4-layer boards with PCB as you describe with very good results. > This one had to be a minimal-cost board so it had to go in two layers. Realize that > the cost is roughly half with 2 layers versus 4. > > Best wishes, > Roger Traylor > >> On Apr 2, 2020, at 2:26 PM, Cam (camfarnell AT bitflipper DOT ca) [via geda-help AT delorie DOT com] wrote: >> >> I'm using PCB 4.0.2. The board is too complex and tight to route with two layers. My next thought is to use four layers with the inner layers being devoted to power and ground with almost the entire layer copper and using thermals where it connects to pins and a gap for non-power pins. But I could see no way to achieve this with PCB. Am I missing something or is that just not supported? >> >> I could simply do thick routes for power and ground on the interior layers but then there is the question of how to get power and ground to SMT components which exist only on the component layer. Hand placed vias near where power/ground pins are on the SMT devices? >> >> Any advice appreciated. >> >> Cam Farnell > >