krw wrote:

Michael A. Terrell wrote:

How were the new caps stored? If it is where they can adsorb
moisture, you can damage them with an iron that is too hot.

I haven't had any problems with cracking but I used to have problems
with end caps falling off. I haven't seen the issue for some time,
though perhaps it was a problem with the manufacturer. Our purchasing
group prefers Murata, so that's what I use (GRM series).


We pre baked some boards and other components before assembly and
reflow. That eliminated cracked multilayer SMD capacitors, tombstoning
of two lead components and losing end caps. That was in N Central
Florida which has plenty of humidity problems. The so called HVAC
'engineers' were clueless about how to control the humidity, so we had
to resort to baking. LSI SMD ICs were backed and heat sealed into
antistatic bags with moisture adsorbing packets.

On Fri, 01 Apr 2016 17:21:31 -0400, "Michael A. Terrell"
wrote:


krw wrote:

Michael A. Terrell wrote:

How were the new caps stored? If it is where they can adsorb
moisture, you can damage them with an iron that is too hot.

I haven't had any problems with cracking but I used to have problems
with end caps falling off. I haven't seen the issue for some time,
though perhaps it was a problem with the manufacturer. Our purchasing
group prefers Murata, so that's what I use (GRM series).


We pre baked some boards and other components before assembly and
reflow. That eliminated cracked multilayer SMD capacitors, tombstoning
of two lead components and losing end caps. That was in N Central
Florida which has plenty of humidity problems. The so called HVAC
'engineers' were clueless about how to control the humidity, so we had
to resort to baking. LSI SMD ICs were backed and heat sealed into
antistatic bags with moisture adsorbing packets.

Sure, baking humidity sensitive parts is common before pick-n-place.
It's a bit less common when hand (de)soldering, though. ;-)

krw wrote:

On Fri, 01 Apr 2016 17:21:31 -0400, "Michael A. Terrell"
wrote:


krw wrote:

Michael A. Terrell wrote:

How were the new caps stored? If it is where they can adsorb
moisture, you can damage them with an iron that is too hot.

I haven't had any problems with cracking but I used to have problems
with end caps falling off. I haven't seen the issue for some time,
though perhaps it was a problem with the manufacturer. Our purchasing
group prefers Murata, so that's what I use (GRM series).


We pre baked some boards and other components before assembly and
reflow. That eliminated cracked multilayer SMD capacitors, tombstoning
of two lead components and losing end caps. That was in N Central
Florida which has plenty of humidity problems. The so called HVAC
'engineers' were clueless about how to control the humidity, so we had
to resort to baking. LSI SMD ICs were backed and heat sealed into
antistatic bags with moisture adsorbing packets.

Sure, baking humidity sensitive parts is common before pick-n-place.
It's a bit less common when hand (de)soldering, though. ;-)


We had a high failure rate on hand soldered FIR chips, before we
started baking them. The bottom of the packaging was the thinnest, and
it would bow out as it released steam during hand soldering. No one in
EE or ME believed me, until I finally got them to try it for themselves.