FEDEVEL
Platform forum

chitransh92 , 09-25-2018, 01:40 PM

Hello Folks,

I recently came across one of the Altium rules of "SMD to Cornor" - Essentially this lets you set the minimum distance after only which you can have a first bend or angle in your track starting from the pad.

Now there are several scenarios where the first bend could be very close to the pad or the track is making an acute angle with the pad.

Question is:
1. How significant is this rule in terms of technicality?
2. Does adding a "teardrop" take care of these acute angle phenomenon?


Thanks..

robertferanec , 09-30-2018, 10:13 AM

1. I have been routing with default Altium settings (so not using this rule) and no problems. I believe, in case there would be something really wrong, in PCB house they may correct it, but when I asked about it, they were not very worried. I know, that when I am using Cadence Allegro, that software takes care of the angle how track is coming out of a pad.

Personally, in some very dense designs, I do not have much choice, but if you are not space restricted, maybe you can control how track goes out of the pad. Also, if you need to follow IPC standards very strictly, double check if there is nothing about it.

2. I believe, teardrops are mostly important in VIAs (I believe, teardrop helps to add some space which may be needed due drilling tolerance). But I am not expert for this

mairomaster , 10-01-2018, 01:45 AM

I agree with Robert. Also if you are worried about accute angle problems, there is a special rule for that. I normally use it, although I don't think it's that important nowadays.

Paul van Avesaath , 10-02-2018, 08:17 AM

I thought the point of this rule was to avoid acid traps during production.. at least that is what the Valor checks seems to indicate.. but i normally have this off because it really kills the freedom of routing.