Hi,
I've been setting up my component and pattern libraries in DipTrace. All my components are thru-hole. I have 30-50 set up, but I'll only need a dozen. That's because I keep screwing up my calc's and I am accumulating components.
In the Pattern editor my options for PAD shape are Ellipse and Oval. Which should I pick and why isn't round an option? (I think I'v picked oval)
I've followed AMPDOCTOR's rules of thumb for PAD size and spacing. Do I use ANSI or ISO drill bit sizes?
I tend to like my units to be mm, but all the drill sizes are in 1000ths, and that's what the doctor ordered. Is that more acceptable?
Here are AMDOC's suggestions.
"The thumb rule I like to use is 1w resistors get 700thou (1.78mm) pad to pad spacing, 1/2w 600 (1.52mm), 1/4w 500 (1.27mm), etc. Ideally you want about 100thou (0.25mm)between the bend and the body. This should be approximately IPC standard but I may be wrong so don't quote me on that. With respect to the pad and hole size, take the nominal lead diameter and add 12thou (0.3mm) and round up to the nearest drill size for your hole, then double that value for the pad size. As far as component to component spacing, I tend to lay out 1/2w and 1w resistors with about 200 thou ( 0.51mm) spacing between them, and 1/4w at around 150 thou (0.38mm). While you can get them closer, if you've got the board space use it. This makes getting in and out with an iron a snap if you need to do any rework or repairs."
The lead bend from body at .012" is a bit tight. I am bumping that way up to 0.100" per bend.
I do not have a handle on the layers and process of making a board. I think I understand the PAD and the silk (outline). I'm good with assigning a pattern to a component. And when I ran a trial of make a PCB from my schematic, it had no errors and actual looked like a PCB. I'm going to save those questions for later to see what I can figure out on my own.
Thanks ya'll for the help and support.