Post by thread:[EE]: PCB design resources

> From: Peter > Sent: Monday, December 19, 2005 8:54 AM > To: pic microcontroller discussion list > Subject: [EE]: PCB design resources > > I am looking for resources on the subjects. I found a few > things on the net and I would appreciate the input of > the list. You seem to put a lot of standard related issues here for PCB design. I think it is nice to know this kind of things in general for PCB design and for electronics design in general. However I would like to point out that standards related issues are often quite complicated and better be handled by standard experts. One more thing, often the standard documents are not cheap to buy but sometimes they are essential to have in order to fully understand what the standard experts say. Regards, Xiaofan

On Tue, 20 Dec 2005, Chen Xiao Fan wrote: >> From: Peter >> I am looking for resources on the subjects. I found a few >> things on the net and I would appreciate the input of >> the list. > > You seem to put a lot of standard related issues here > for PCB design. I think it is nice to know this > kind of things in general for PCB design and for > electronics design in general. Yes but I am trying to make up my mind on essential things like board size and configuration (which cannot be changed later - as opposed to the layout, which can). I.e. I want covering figures for clearances and so on so I can move things later if needed. > However I would like to point out that standards > related issues are often quite complicated and > better be handled by standard experts. I agree but this is not the case this time. Peter

> From: Peter > Sent: Wednesday, December 21, 2005 3:12 AM > > > You seem to put a lot of standard related issues here > > for PCB design. I think it is nice to know this > > kind of things in general for PCB design and for > > electronics design in general. > > Yes but I am trying to make up my mind on essential things like board > size and configuration (which cannot be changed later - as opposed to > the layout, which can). I.e. I want covering figures for > clearances and so on so I can move things later if needed. > I see and I think you are doing the right thing. Maybe to get hold of some standards will help even though they might not be cheap. I also guess that you might be in the industrial automation field which needs to take care of many standards. If board space is not an issue then of course it is good to cover all the possible applicable standards. This may not be the case though. Even for the basics like creepage distance and clearance, there are so many different standards. Typically my design follows EN50178/EN50020/UL508/UL840 depending on the application and I think there are many more standards out there. There are also different interpretations from the standard experts and the certification body (very similar: the lawyers and the judges might have different interpretations of the law) and it is sometimes quite difficult to decide the correct things to do. ;-( This is quite like EMC requirement. Different product need to fulfill different standards. For us we need to consider EN60947-5-2/EN61326/EN50295/EN61000-6-2/NAMUR NE21 depending on the product. It makes no sense to fulfill NE21 (which is quite tough) if not necessary. Regards, Xiaofan