Hi, We cann't Provide more GND Plane ( 4 ) as you specified and There is no Provision for Splitting VCC2.5 in VCC3.3 Plane as There are 12V and 5 Volts are Already Shared the VCC3.3 and 2.5 Plane Is there any Other Layer Stack up Can you Suggest. My Question is Why Multiple Ground are Very much Needed? Thanks in Advance Regards Nagaraj -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of vasudevan.duraiswamy@xxxxxxxxxxx Sent: Monday, December 02, 2002 5:34 PM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: 10 Layer Board Stack up Hi, It is correct that the layers should be symmetrical, to provide better copper balancing, Power planes are generally defined by power integrity / decopling requirement impedance requirement Routability Your stack up can be modified as follows 1)Top Signal 1 2)GND 3)Signal 2 4)VCC3.3 5)GND 6)VCC2.5 7)GND 8)Signal 3 9)GND 10)Bottom Signal 4 Routing, switch the signals between layer pair Top Signal 1 and Signal 2 or between layer pair Bottom Signal 4 and Signal 3 Don't switch over routing between Signal 1/2 to Signal 3 / 4 Incase of more routing layer requirement, make layer 4 & 7 also routing layer , make layer 5 split power plane of VCC 3.3 & 2.5, make layer 6 as GND Regards, Vasudevan D Technical Leader - PCB Design, CFT Philips Software Centre Pvt Ltd, Philips Innovation Campus, # 01, Murphy Road, Ulsoor, Bangalore - 560 008. India Tel: +91 80 5579 000 extn : 5030 fax : +91 80 5546 645 stephanie.goedecke+FromInterNet@ philips.com To: si-list@xxxxxxxxxxxxx Sent by: cc: (bcc: Vasudevan Duraiswamy/BTC/CFT/PHILIPS) si-list-bounce@xxxxxxxxxxxxx Subject: [SI-LIST] Re: 10 Layer Board Stack up Classification: 2002-12-02 02:48 PM Please respond to stephanie.goedecke+FromInterNet Hi, generally, the layers should be symmetrical. The details of the layout depend on the details of the board. Stephanie Goedecke Philips - SP3D Chip Design GmbH Petersbrunnerstr.17 82319 Starnberg / Germany Phone: +49-8151-270-160 Fax : +49-8151-270-200 Hi , In 10 Layer Board stack How Multiple Ground Plane Will be More effective and Why. Is there any Formula/Thumb rule behind this. most of my Critical Signal ( CLK) are Running at Signal Layer 1 and My Board Stack up is Top GND Signal Layer 1 VCC3.3 GND VCC2.5 Signal Layer 2 Signal Layer 3 GND Bottom Thanks in Advance. ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu