I'll give it a try.
1 - 20 to 30 mils.
2 - After plating.
3 - It's more a factor of your minimum
annular ring. I usually try for
10 to 15 mils depending on the
density of the board and the current
going thru the hole.
4 - Again it depends on density & current.
I usually go with 20/40 & 25/50 (hole/pad)
but most of my boards are not that dense.
Many go as small as 12 & 15 mil holes.
5 - 8 mils minimum to 30 mils maximum over
the max dimension of the lead.
6 - Yes, 52 mils is good. See Above.
.042 across corners +.008 = .050
.042 + .030 = .072 so hole size
should be between 50 & 72 mils.
7 - Again it depends upon the amount of
current.
I suggest you get a copy of IPC-2221 & IPC-2222 from www.ipc.org.
It will give you answers to many of your questions.
Also do not forget to put a 50 mil or so trace around the boarder
of the board on internal power & ground plane layers so that the
planes do not extend to the edge of the board.
Good luck,
Steve Smith
Product Engineer
Staco Energy Products Co.
Web Site: www.stacoenergy.com
> -----Original Message-----
> From: Paul Cooper - Myrica [mailto:[EMAIL PROTECTED]]
> Sent: Friday, December 07, 2001 4:18 PM
> To: Protel EDA Forum
> Subject: [PEDA] Starting out with Protel99, Questions
>
>
>
>Am trying to layout my 1st board since college and have a few general
>PCB layout questions. Board will be about 2x3", and max Frequency is
>about 100Mhz, althoug most much slower.
>
>This is a test board, which will be made in the 10's, not a production
>board (which is why a chip designer is doing it)
>
> 1) Is there a standard or rule of thub that can be applied to the
> seperation for a split plane ?
>
> 2) For plated pads and vias, is hole size in layout before or after
> plating. ie if i set hole size to be 50mil, will it compensate for
> fact hole will be plated and compensate drill size so hole is 50mil
> after plating?
>
> 3) Is there a standard or rule of thumb for dimensions of pad in
> relation to hole size ? From most of the library components I
> looked at, it seems hole is about 2/3 pad size.
>
> 4) Is there a standard via size/sizes ?
>
> 5) For a given size diameter component lead is there a guidline for
> hole size ?
>
> 6) for a component with square pins, .025mil (+- .005) mil on a side,
> I was going to use pads of diameter 80, hole 52. This sound reasonable.
>
> 7) For a thick track, say 30mil to 50mil, is it normal to use multple
> small vias ?
>
> Any other pointers welcome.
> Any help greatly appreciated.
>
> Regards
> Paul
>
> --
> Myrica Networks, Inc. Paul Cooper
> 4350 Executive Drive, Suite 200 [EMAIL PROTECTED]
> San Diego, CA 92121 (858) 362-0850 (Fax 0855)
>
>
>
>
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