TECHNET Archives

September 1999

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Condense Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Sender:
Subject:
From:
Mark Holmes <[log in to unmask]>
Date:
Fri, 24 Sep 1999 09:09:21 +0100
Content-Type:
text/plain
MIME-Version:
1.0
Reply-To:
"TechNet E-Mail Forum." <[log in to unmask]>, Mark Holmes <[log in to unmask]>
Parts/Attachments:
text/plain (45 lines)
Hello All,

This is a question for all you board assemblers out there,

I originally sent to this message to the Designer Council list, so I
apologise in advance to anyone who subscribes to both forums.

All the data I have regarding pad sizes (e.g. IPC-2221 9.1.1) give examples
on how to calculate Minimum pad sizes, usually from a PCB fabrication
standpoint. IPC-2221 states that all lands and annular ring shall maximised
wherever feasible, consistent with good design requirements and electrical
clearance requirements.

My questions are: How do I determine the pad size that will give me the best
soldered joint?
Would the minimum pad size calculated by the formula in section 9.1.1 still
provide a good soldered connection?
Are there upper limits to the size of a solderable surface of a pad?
Would the Ideal be to maximise all the pad sizes to one size that meets the
requirements of 9.1.1 for all holes?

I am surprised there is no reference to soldering in the standard relating
to pad sizes, I am sure the pad size must have some effect on the solder
fillet.

Any information would be appreciated,

Thanks in advance,

Mark

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################

ATOM RSS1 RSS2