The manufacturer takes care of this for you.
The hole size in the PCB is the final size. Let say if in the drill files the hole size is 20mil, we will use 22mil drill to make the hole, after plating the hole size will be 20mil.
Nothing to worry about!
Sparky,
I find this somewhat disturbing. I have Used Olimex and PCB-POOL to make short production runs, and with them, you specify the exact drill to use, not the finished hole size. The data sheets from most components specify the correct drill size and I just use these without any problems. If not, the rule of thumb is to add 0.4mm to the leg diameter of the pin to account for plating and such.
This means if I get a proto build by Sparkfun, I will need to modify the drill sizes before going into production with pcb-pool, which makes me nervous that I will make a typo and blow a production run.
Any thoughts or experiences you have with this?
Jamie
We’ve never really run into a problem.
It’s actually much easier to follow the recommended land/layouts with this method. The manufacturer recommends a hole size, you build that diameter into your footprint, and the plated hole comes out the recommended size.
I have experienced both types of plating services - ones where I have to adjust my design, and services where they adjust the holes for me. I particularly like not having to change designs on my side…
Besides, we use Gold Phoenix for production runs 
-Nathan
I’ve been doing professional PCB layouts for almost 30 years (since tape up days!) and my experience is that almost all good PCB houses use finished hole size.
The reason is simple; the manufacturer knows their process and tolerances and you don’t (necessarily) when you design your PCB.
For instance, are you using 1/2 oz., 1 oz. or 2 oz. plating? All will affect the plating thickness on the finished PCB based on the manufacturers process. They knwo exactly how much to “overdrill” the hole for your particular plating spec to realize the finished hole size.
Like Sparky said – it’s nice not having to change your design for any given PCB house. In fact I would never stand for it, it’s simply too labor intensive and prone to errors.
Thanks for the explanation. I think I was mistaken on this and the board house I used did use finished hole size vs drill size.
Sorry for the stupid previous post Sparky :lol:
Jamie
Not at all! There are no stupid questions here!
I just hope you guys don’t realize how limited our knowledge really is 8)
It’s guys like you and MGP that really help us out. (Thanks MGP!)
-Nathan