At 63% notional tin content there should be 63 #/kg of Sn for every 100 #/kg
of solder. A ratio of 63/37=1.7
At 61.5% actual tin content there is only 61.5 #/kg of Sn, or 38.5kg Pb.
Therefore to restore the ratio you need 38.5 x 1.7 = 65.45, less the 61.5
you already have = 4#/kg for every #/kg of pot capacity.
Tin depletes in wave soldering as it is the more active of the two
constituents and therefore tends to get used quicker and oxidise faster etc
compared to lead.
Best regards
Mike Fenner
Applications Engineer, European Operations
Indium Corporation
T: + 44 1908 580 400
M: + 44 7810 526 317
F: + 44 1908 580 411
E: [log in to unmask]
W: www.indium.com
Leadfree: http://Pb-Free.com
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Scott Kauling
Sent: Wednesday, October 24, 2001 2:59 PM
To: [log in to unmask]
Subject: Re: [TN] Adjusting the alloy composition in the solderpot
Daan
I do not have the formula, sorry. I would lean on your solder supplier to
help you.
Have you determined a root cause for the Sn levels to decrease? I was
wondering because, we are beginning to use white tin for a final finish.
Scott Kauling
-----Original Message-----
From: d. terstegge [SMTP:[log in to unmask]]
Sent: Wednesday, October 24, 2001 9:29 AM
To: [log in to unmask]
Subject: [TN] Adjusting the alloy composition in the solderpot
Hi Technet,
I just received an analyses report for our solder bath composition, and my
Sn level is at 61.5 percent instead of the nominal 63 percent. This is at
the edge of the J-STD-001C specification, so I'll have to add some pure tin
to the pot.
Last time was many years ago, and unfortunately I forgot the formula for
calculating the amount of tin to add.
It can't be that difficult, but I thought it would be quicker to ask.
Thanks,
Daan Terstegge
SMT Centre
Thales Communications
Unclassified mail
Personal Website: http://www.smtinfo.net
------------------------------------------------------------------------
---------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send the following message: SET
Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
------------------------------------------------------------------------
---------
----------------------------------------------------------------------------
-----
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send the following message: SET
Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----
---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------
|
