Well,
If you solder in addition to crimping:
1. You add cost and tick off the operators
2. If you are soldering to stranded wire, you will change the flexibility
of the connection because, for a short distance, you change flexible
stranded wire to solid wire.
3. Unless you are soldering using pure wire solder, i.e. no flux, you are
going to get flux wicking up under the wire. If it is a high solids rosin
(good ol RMA), then you might or might not have corrosion. You WILL have a
visible residue that you cannot clean. So if you normally the flux used in
hand soldering, you ain't a gonna get it out. Only dilute it and force it
farther in. If you are soldering with pure solder wire, then you probably
have a very bad solder connection anyway.
4. If you are using a low solids flux, you must still be prepared to
answer questions about green residues. The flux activators over time may
result in a greenish residue that is not exactly corrosion. Karen
Tellefsen of Alpha Metals did an excellent paper on green residues on
circuit boards. Not all are detrimental.
5. On the other hand, you do get a better electrical connection.
6. On yet another hand (a little known side effect of Mountain Dew), one
of our experienced engineers has been working with time domain
reflectometry, using it to locate faults in rigid and semi-rigid co-ax, and
he showed me some interesting graphs the other day. Blobs of solder in a
connector changed the TDR characteristics. With blob in place there was
one spectrum and with solder blob removed, you have a different spectrum.
So, if you are working with RF signals, the use of solder in addition to
crimp may alter the signal transmission characteristics.
Was this what you were looking for?
Doug Pauls
Rockwell Collins
---------------------------------------------------------------------------------
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 e-mail to [log in to unmask]: SET Technet NOMAIL
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
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
---------------------------------------------------------------------------------
|
