Stephen:
There isn't a time limit on the solder used in the test. There are purity tests for the solder however.
Contiminates from the boards like copper, gold or nickel or from the solder pot or utensils (iron, etc.)
will accumulate over time. Also tin oxidizes faster than lead which will eventually change the solder
composition.
As you can imagine from the above, usage and amount of solder replenishment affect the life of the solder.
My recommendation is to have the solder pot analyzed regularly to the specifications in J-STD-003??
(somebody help!!! my mind just went blank on the proper spec number - anyway its one of those IPC specs
with a similar number).
Hope this helped.
Don Vischulis
Stephen Ayotte wrote:
> A quality organization that I work with has a number of questions
> concerning the use of solder pots, techniques, limits, conditions,
> constraints as they relate to solder shock testing of laminates. They are:
>
> I need some information concerning the expiration of 63/37 solder when
> used in a solder pot.
> I have looked for any kind of standard that
> would describe a time limit for the solder, but haven't found a thing.
> We thermally stress circuit boards at 550o F (288o C
> ) for ten seconds, referencing test method IPC-TM-650, Number 2.6.8.,
> revision
> C, date 8/97, sections 5.4 - 5.6.
> But how often should we replace the solder ?
> Is there a time constraint or quantity constraint that dictates when
> to replace the solder with new material ?
>
> In addition, is there any information concerning the procedure for
> replacing
> the solder in the pot ?
> Is there a percentage of copper that must be added to the 63/37 tin/lead
> solder ? Or some other preparation needed for proper solder flow.
>
> Please respond to my e-mail address with any pertinent information that
> will assist me.
> I would also recommend adding this information to your test methods
> IPC-TM-650 for other industries to reference.
>
> Look forward to hear from you.
> Sincerely,
>
> Christopher S. Barton
>
> IBM Corporation
> [log in to unmask]
>
> Are there specific directions with which the testing is to be performed;
> side to be floated, flip coupon between floats when doing multiple tests,
> cool down technique, bakes before floating, etc?
>
> Thx.
>
> Stephen Ayotte, IMD Product Quality Engineer
> Dept. 5QE, Bldg. 14-3, Office BB11
> Phone (607) 755-1537, t/l 855-1537
> Pager (607) 755-7243 Pin #863 - external, 5-8888 Pin 2863 - internal
> Fax (607) 755-4649
>
> ################################################################
> TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information.
> For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
> ################################################################
################################################################
TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################
|
