How to choose drill size with known pin diameter?

[Michael Noone]

Hi - does anybody have any suggestions for how to choose a drill size for a
known diameter pin? For example I'm making a layout with a piece that has
..02" diameter pins. Not only does the drill need to be a bit bigger than
that just so that the pin can be put in without excessive force (and so
that solder can flow through it) - but also since the hole will be plated
it needs to be that much thicker. So - is there a good guideline for how to
size such holes? Also - are there "standard" drill sizes, or is it best
just to see what the board manufacturer uses? Thanks,

-Michael J. Noone

 

[James Meyer]

On Tue, 31 May 2005 16:30:17 -0500, Michael Noone <mnoone.uiuc.edu@127.0.0.1>
wroth:

Hi - does anybody have any suggestions for how to choose a drill size for a
known diameter pin? For example I'm making a layout with a piece that has
.02" diameter pins. Not only does the drill need to be a bit bigger than
that just so that the pin can be put in without excessive force (and so
that solder can flow through it) - but also since the hole will be plated
it needs to be that much thicker. So - is there a good guideline for how to
size such holes? Also - are there "standard" drill sizes, or is it best
just to see what the board manufacturer uses? Thanks,

-Michael J. Noone

Some board manufacturers will deliver boards with specific hole
diameters after plating. Some manufacturers only drill the original hole with
the specified diameter and it's up to you to determine the finished, plated,
hole diameter.

In short, pick a manufacturer based on other criteria, and then work
with them to get the proper finished hole diameter. If they only drill the
original hole to what you specify, they can tell you what the build-up due to
plating will be.

Jim

 

[Joerg]

Hello Michael,

In addition to Jim's explanation: You should also find out what the
manufacturer of your part specifies as the ideal hole diameter after
plating. Else you might find that drill position tolerances and other
deviations jam up the part, IOW it won't insert unless you force it.
Also, solder may need to wick into there.

Regards, Joerg

http://www.analogconsultants.com

 

[Peter Bennett]

On Tue, 31 May 2005 16:30:17 -0500, Michael Noone
<mnoone.uiuc.edu@127.0.0.1> wrote:

Hi - does anybody have any suggestions for how to choose a drill size for a
known diameter pin? For example I'm making a layout with a piece that has
.02" diameter pins. Not only does the drill need to be a bit bigger than
that just so that the pin can be put in without excessive force (and so
that solder can flow through it) - but also since the hole will be plated
it needs to be that much thicker. So - is there a good guideline for how to
size such holes? Also - are there "standard" drill sizes, or is it best
just to see what the board manufacturer uses? Thanks,

-Michael J. Noone

When I order PC boards, I specify the finished hole size, and let the
board shop determine the required allowance for plating. Normally,
the smallest size I specify for component leads is .030 (for TO92
transistors), but usually use .035" for most parts (ICs, 1/4W
resistors, etc.)

The finished hole size should be at least .010" larger in diameter
than the lead.

--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
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Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

[Ban]

Michael Noone wrote:

Hi - does anybody have any suggestions for how to choose a drill size
for a known diameter pin? For example I'm making a layout with a
piece that has .02" diameter pins. Not only does the drill need to be
a bit bigger than that just so that the pin can be put in without
excessive force (and so that solder can flow through it) - but also
since the hole will be plated it needs to be that much thicker. So -
is there a good guideline for how to size such holes? Also - are
there "standard" drill sizes, or is it best just to see what the
board manufacturer uses? Thanks,

-Michael J. Noone

I choose pin dia +0.015" for finished diameter and +0.01" for plating thru,
so with your 0.02" pins the drill diameter is 0.045". Now the cheap board
house(Olimex) has only ... 0.039, 0.043, 0.051, ... without extra charge
available, so I choose 0.043".

--
ciao Ban
Bordighera, Italy