Talkin' some shock here upon immersion , do we ?;
tapes crumbling back to granules ;
we are truly on other scale ; first melt , now freeze .
And unpack and retape does sound extreme as well .
Al, did you validate this need ?
often reels live even that long without much drama .
and if you really need it ; perhaps a dry pass prior to your profile ?
That is paste, place, run 100'C less, than profile (within hours).
Just a thought (worked in past).
paul
-----Original Message-----
From: joyce [mailto:[log in to unmask]]
Sent: Wednesday, 15 September 1999 8:56
To: [log in to unmask]
Subject: Re: [TN] Baking SOIC packages to dry them prior to reflow
solder
can you use dry nitrogen to bake out?
At 04:13 PM 9/14/99 -0500, you wrote:
>Al,
>Those are old parts. Hmmm. Although weight loss studies I have done and
>have seen from vendors show most of the moisture leaves components within
>the first four hours, these investigations have not been with parts that
>have had the possibility to suck up moisture for five years. (Well they
>wouldn't be doing it continuously.) I personally would be a whole lot more
>comfortable with a 24 hour temperature soak, at the temperature you
>mentioned. I would expect that at this temperature you should be OK with
>respect to growth of surface oxide, unless of course you are right on the
>hairy edge of your pass/fail criteria for solderability. I would also be
>inclined to use them as soon as possible after they come out of the oven,
as
>I have no idea how susceptible the particular SOICs you have are to
moisture
>pick-up.
>
>regards,
>Bev Christian
>Nortel Networks
>
>
>> -----Original Message-----
>> From: Alan Shaw [SMTP:[log in to unmask]]
>> Sent: Tuesday, September 14, 1999 4:34 PM
>> To: [log in to unmask]
>> Subject: [TN] Baking SOIC packages to dry them prior to reflow
solder
>>
>> I have 5 year old plastic SOIC packages on reels and want to dry them out
>> in
>> an oven rather than leave it to the pre-heat of the reflow solder
machine.
>> Production asked for temperature and time for the SOIC to be in the oven.
>> My initial thoughts are to put them in a cold oven and set the thermostat
>> to
>> 110'C and leave them baking for 4 hours. Then turn off the oven. Remove
>> them
>> when cool and use in the insertion machines the next day.
>> Is the temperature and time suitable?
>>
>> The leads have passed a solderability test already, would the time in the
>> oven have a significant effect on solderabitiy?
>>
>> Al Shaw
>> ashaw at napcosecurity dot com
>>
>> ##############################################################
>> TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for
>> additional
>> information.
>> If you need assistance - contact Gayatri Sardeshpande at [log in to unmask]
or
>> 847-509-9700 ext.5365
>> ##############################################################
>
>##############################################################
>TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for
additional
>information.
>If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
>847-509-9700 ext.5365
>##############################################################
>
##############################################################
TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################
##############################################################
TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################
|
