My understanding is:-
“Unsupported”- E.g. Single-sided
board design non-plated hole for PTH components. Not solder is able to fill the
hole and only with one fillet being formed on the single pad for the PTH component
of the PCB.
“Supported” – E.g. Double-sided
board design with plated through hole for PTH components. Solder will fill the
PTH hole with fillet formed on both side of the pads of the PTH component.
From:
DesignerCouncil [mailto:[log in to unmask]] On Behalf Of
Sent: Tuesday, 12 August 2008
11:59 PM
To: [log in to unmask]
Subject: Re: [DC] IPC-2221
Hi Don,
My understanding of
“supported” and “unsupported” holes is that they are
both PTH, but “supported” holes will have a pin inserted through
them and soldered. An example of an “unsupported” hole would
be a through via. The term “supported” and
“unsupported” is used for Z-axis calculation of CTE to eliminate
barrel cracking, I believe!
Respectfully,
Steven D. Roy
PCB Designer
Audio Authority Corp.
(859) 233-4599 X-159
-----Original
Message-----
From: DesignerCouncil
[mailto:[log in to unmask]] On Behalf Of
Don Larisey
Sent: Tuesday, August 12, 2008
11:39 AM
To: [log in to unmask]
Subject: IPC-2221
In IPC-2221 it specifies some holes as “Supported” and
“Unsupported” and I used to know what the difference is but I
don’t remember. Would someone please give the explanation?
Don