10 Replies Latest reply on Jul 15, 2009 8:58 AM by yu.yanfeng

    Hope to Get Sample Gerber data from You



      As seen, I have posted much for SIP(Self Intersecting Polygon) issue in Expeditionpcb's Gerber output, but got less feedback from You, the Expeditionpcb Users. These day, Things got worse when more and more designs be finished in Xtremepcb platform and send to fabs. We received lot of complains from our fab partner, they complaining there are SIPs(Self-intersecting Polygon) in our data, and make them in trouble,sometimes they request a repaired gerber data.  Our managment let us to visit fabs next week and get thing done.


      Personally I really known why this happened and think SIPs is common to all Expeditionpcb design with comlex positive planes .Partionally, It is caused by the design, but mostly  is caused by Expeditionpcb. We know you can't expect any Layout system always output gerbere data which is without any SIPs,  We also know that  one of main feature for the CAM system is the capability for repairing SIPs in the input data. Unfortunately, most of CAM system used by our fab partners can't repair automatically SIPs in our Gerber output generated by Expeditionpcb, and Expedtionpcb almostly output every data with SIPs for those planes layers when using Decimal .5 data format. We are not the only one who encouting this symptom. I found other Expeditionpcb custermer( Charales Ietswaard ) reported this symptom in the community. Charales have a workaroun(He use Wise's Gerbtool to read in all gerber data and Export out it again to eliminute SIPs).  I think this workaround isn't effective, it only be effective for some small  designs, not to all. 


      We have logged this issues in the supportnet began in Jan 2008 and remarked it as one of top issues in a meeting with Mentor BD




      Becasue My boss want us to solve this problem a.s.a.p I think I need you helps. Because the problem is definitely in Expeditionpcb side,So one sample gerber data with positive planes is enought to help me get the problem clear.


      Thanks in Advances



        • 1. Re: Hope to Get Sample Gerber data from You

          There are much gerber data which including SIPs. Why  they only complain to our data generated from Expeditionpcb? I guess the data from Expeditionpcb may have erratic display in the CAM system.


          Left pic is a shape display in Genesis 2000, the right is a shape display in Expeditionpcb. Why it looks different? It's a bit of difficult to describe clearly in short. I think me and Mentor all really know why.

          Of course, the up-to-date CAM system can repair it automatically whiling reading into the system. However, You can't expect all pcb fabs updating their CAM system immediatlly and I think things should be correct at first.


          I see Jerry have a post about planes optimization.I think He maybe in the process to get Expeditioncb Panes engine optimized. I hope I can hear some voices from Jerry and other Expedtionpcb core team.

          sip3.bmp    sip4.bmp




          During last years, I have chances to talk with Mr. Henry Potts, Mr. Tom Floodeen, Mr.John Issac, Mr. David Wien and  Mr. Joe Krolla. All of them are eager to listen to customer voice,especially I have talked with Joe much times. I hope Joe can see this post, forward this issues to the product team.

          • 2. Re: Hope to Get Sample Gerber data from You

            No one is willing to provivde sample data? From Tommorrow, I will visit pcb vendors and tell the story.


            • 3. Re: Hope to Get Sample Gerber data from You

              Aftter talking with Orbetch's engineer and pcb vendor, We clearlly understand why. it's clear this is a bug in Expeditionpcb and Genesis 2000,mostly in Expeditionpcb side. I have proposed a remedy to this symptom, it seems now everything is ok. Also I show and teach Mentor's Engineer how to analyzed the problem and do basic calculation based the basic Arbaric.


              If you are interest in this story and wish to know the story, please post your sample data here and I will send the answer to you in personal.



              • 4. Re: Hope to Get Sample Gerber data from You


                Just a side comment on your list.

                I am not aware of your expertise level, so do not take this in a bad way.  If you are already knowledgeable about this then maybe it will help someone else.

                I do not have the software to look at, since I am currently unemployed.  Although I just want to make sure that when you read in the data to Valor that you set the BOARD / PLANE / NEGATIVE options for your negative and split plane layers. Make sure they are in the correct position in the stack up and make sure the drill manager info is correct for both plated and unplated drills as well as the drill span of all of your drill files.


                Val Fox

                • 5. Re: Hope to Get Sample Gerber data from You



                  I have seen this problem too and I have seen the results in Valor and GerbTool.  This problem comes and goes depending upon what version of the software you were using going all the way back to the VAX days.  I have not responded earlier because I have always ben able to fix it by moving vertices or adding another shape.  I don't even think about it when I open an old job and have to play with the shapes again.



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                  • 6. Re: Hope to Get Sample Gerber data from You

                    Hi Dwain,

                    Thank you very much for confirming this sympotm. Yes, it's easy to fix it if you using CAM tools. However, not all desinger are willing to do it. I worte a Chines PPT to detail everything behind this symptom and propose a algrithm to repair it. Late, I may translate it into English if I received some sample data from this community.


                    • 7. Re: Hope to Get Sample Gerber data from You

                      Hi Val,

                      Your comment not in the point, but your another post(http://communities.mentor.com/message/5832#5832) close to the point.


                      • 8. Re: Hope to Get Sample Gerber data from You
                        Wim Creyghton

                        Hi Yanfeng,


                        We also know about the Gerber output problem.


                        We try to convince the PCB manufacturer to use ODB++ instead off Gerber.



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                        • 9. Re: Hope to Get Sample Gerber data from You

                          Hi Wim,


                          Thank you very much for confirming this symptom.


                          Unfoturnately,  2007.2 ODB++ output also has a severe bug. If thermal ties be edited, sometime, those ties will missed in ODB++ but exists in the gerber data, this make pcb vendor confused.



                          • 10. Re: Hope to Get Sample Gerber data from You


                            Recently, I have to vist all our fab partners to discuss this issues.  All of them hope all gerber data should be without SIP issues. Also I have received Mentor' reply. Here is the reply:


                            This is regarding the Service Request 2222236670 , 2192936925

                            The Defect report dts0100351869 (associated to the above SRs) has been evaluated. Unfortunately we do not plan to execute the solution this time or in any future release of Mentor Graphics software.

                            We prioritize defect reports and enhancement requests based on several factors: 
                            -criticality of the issue,
                            -the number of customers reporting the issue,
                            -the resources involved in making the change,
                            -strategic product direction.

                            We continually evaluate customer input as part of our quality system, and we encourage you to continue to provide us feedback on our products.
                            We appreciate your input on our products. Your feedback is crucial in helping us continually monitor and improve the quality of our releases.