The trick (YAG) seems to be the ramp-up of pulses. I don't remember what
sequence was optimal, but if you had tens of variations of solder and
components, there was a lot of experimenting to find the individual shot
ramp-ups. The enthusiasm for laser soldering faded away....this was 15 years
ago...at least. 
Inge

-----Ursprungligt meddelande-----
Från: TechNet [mailto:[log in to unmask]] För John Burke
Skickat: den 6 december 2007 19:20
Till: [log in to unmask]
Ämne: Re: [TN] Laser Soldering vs Selective Soldering

CO2 has been around since the mid '80's as soldering systems (Dynapert as
was) as have YAG soldering systems, I have used both - they both work.

CO2 is less forgiving as you have to have total accuracy, if it hits the
laminate it will basically burn it as from memory you get total absorption
at that frequency.

Use a (prime frequency) YAG and it will be more forgiving as the joint has
high absorption whereas the laminate is from memory 10 to 20% so you will
not have the same effect, in fact I have seen demonstrations where the
vendor was soldering joints by lasing through the BACK of a board (Basel
Laser Technik - 1986)

If you really want to do this there are vendors who make laser rework
equipment which might be suitably modified.

Kind regards,

John

 
 
John Burke
 
(408) 515 4992
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Ray, Carl (GE Indust, GE
Fanuc)
Sent: Thursday, December 06, 2007 5:57 AM
To: [log in to unmask]
Subject: [TN] Laser Soldering vs Selective Soldering

Hi All,
 How many of you "out there" have any experience with laser soldering
machines verse selective soldering machines? Currently we have several types
of selective soldering equipment but due to our designs we are having
significant issues with adjacent components. 
 I have seen some equipment but do not have experience with the venders or
process.

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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 or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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 or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------