Hi, I remember in physics we can estimate how much energy is needed for an electron to escape the surface of a conductor and also the significant difference between the speeds of electrons and light (EM waves). Some people are trying to explain the phenomena intuitively by some similarities. However, we could be easily confused by mis-understanding the behavior of waves and particles and the relations. Is EMI caused by the off-PCB electrons at all? Etc. From practical engineering point of view, it may be O.K. However, from scientific point of view, we need to be careful. There are some other similar situation in our society such as the famous 2.5 D naming problem. Regards, Mick -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Kanakaraj Sent: Monday, August 30, 2004 11:50 AM To: pcb_user@xxxxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: 90 degree bend Hi, The simplest thing is that when you make 90 degree turns on the pcb track, the electron moving in it cannot make sudden turns..( remember inertia of direction in physics and a bus making a 90 degree turn at full speed)... so some of the electrons will jump out of the pcb track and will cause emi issues.. and Andy, Andrew, Ray anderson and the seniors will give you more inputs on that. Well I am too like you. a beginner :-) Kanak ----- Original Message ----- From: "New Bee" <pcb_user@xxxxxxxxxxx> To: <si-list@xxxxxxxxxxxxx> Sent: Monday, August 30, 2004 5:19 PM Subject: [SI-LIST] 90 degree bend > Hi > > I am a new PCB designer. > > I have a silly doubt - really do not know if I ask it in this forum. > > > why is it suggested not to have 90 degree bends for the traces while routing ? > > If some one can give me the electrical/electronics and manufacturing reasons I will be greatful to them > > If this is not the right forum to address this please let me know=20 > where can I ask > > Thanks in advance > Kam > > Yahoo! India Matrimony: Find your life partner online. > > > Yahoo! India Matrimony: Find your life partneronline. > > ------------------------------------------------------------------ > 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:=20 > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > List FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ > > List technical documents are available at: > http://www.si-list.org > > List archives are viewable at:=20 > //www.freelists.org/archives/si-list > or at our remote archives:=20 > 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: =20 //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 =20 ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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