When I look at the pin layouts I can get the spacing done with no problem. However, I’m trying to figure out the size of the holes/pads, and that’s where I’m running into problems.
It says that the smaller ones are 0.92 +/- 0.8 diameter (I assume that’s in mm). Is that the size of the hole? If so, does it matter how much larger I make the pad? Also, directly under the 0.92… there is a box with some numbers and symbols. What does that refer to?
0.92+0.08 is 1 mm. But if you specifiy a 1mm drill then the resulting hole might end up larger if the drill moves around.
Ok, I realized that I still had my old drafting book from college in my bookcase. It doesn’t completely explain the symbols. But the circle crosshair means it is about the position accuracy of the hole centers. The 0.1 means it should fall within a circle of that diameter at the given dimensions. The M in a circle means Maximum Material Condition, which I haven’t heard of myself. (I guess I was asleep in class at the time) But this should get you a bit further in understanding, or at least help search further:
The A, B, Z and Y probably means the position accuracy is referenced to those sides (datums) of the PCB which have those labels. The meaning of S-within-circle is something I cannot deduce from my book. It is in dutch and talks about P (positie =position) and V (vorm =shape) deviations. It probably doesn’t help, but that is all that I can offer now.