Grant,

Sounds like you have a couple of 'opportunities' here.

First as an old test person, I would suggest you make sure that your ICT
folks are using the self cleaning probes on the fixture. With a reasonable
amount of flux these probes will survive a lot longer than an normal probe.

Second, it sounds like you may have an excess of flux?? Or maybe it is just
the way I am interpreting what you are saying. Just take a look anyway.

On the subject of cleaning, well there are a couple of things to look at
here also. You could get a cleaner and add a process or you may want to look
into no-clean flux for the process you already have.

In my 'life' in production here we have moved to no-clean and when we
started SM process we started out with no-clean. We evaluated the move up
front, and have not had any issues to deal with once making the move, so I
can say that from our standpoint, no-clean is a big plus. AND, our ICT folks
have no complaints no matter how long the board takes to get to them.

Good luck, and let me know if I can be of any more help.

Richard Hamilton
Clemar Mfg. / Rain Bird
[log in to unmask]

> -----Original Message-----
> From: Grant Emandien [SMTP:[log in to unmask]]
> Sent: Thursday, August 19, 1999 7:18 AM
> To:   [log in to unmask]
> Subject:      [TN] Solder joint curing
>
> Hi all out there,
>
> What is the average period for a solder joint (reflow and wave) to 'cure'?
> I
> also state that I don't quite know what cure means in this instant - but
> the
> general problem we have is the minimum period (if there is such a thing!)
> required for a solder joint to cure before introducing it to ICT under
> reasonable conditions of stability.
>
> Our test guys are complaining that the assemblies reach there machines too
> late (hours later), resulting in hardened flux which the test pins have
> difficulty in penetrating, causing damaged pins, retesting and hence
> unnecessary wear of the test fixtures and reduction in throughput.
> Introducing the assemblies too early while the joints are still in
> 'transition' may also result in retesting (true or false?).
>
> As you may have guessed, we don't clean boards as a norm however, this may
> be the way to go in future as will be experimenting with a cleaner
> shortly.
>
> Cheers
> Grant
>

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