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Mail Archives: geda-user/2018/07/11/07:53:55

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To: geda-user AT delorie DOT com
From: "Richard Rasker (rasker AT linetec DOT nl) [via geda-user AT delorie DOT com]" <geda-user AT delorie DOT com>
Subject: [geda-user] Some MSL questions
Message-ID: <5bbf7252-eb65-59a3-71c5-90ee617f0650@linetec.nl>
Date: Wed, 11 Jul 2018 13:52:13 +0200
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Reply-To: geda-user AT delorie DOT com

Hello,

It appears that an increasing number of integrated circuits have 
Moisture Sensitivity Level 2 or higher.

As I usually only assemble a few reflow-prototypes myself, I end up with 
an increasing number of components which are expired MSL-wise.

In simple cases (e.g. SMD LED's) and MSL-2 I usually take the gamble, 
and I never had a failure so far.

However, I'm more wary with MSL-3 components, especially the larger 
IC's. These are not just more difficult to replace, but can also sustain 
damage that doesn't show right away.

I was wondering if people here have experience in this area. Has anyone 
had any trouble with MSL-2/3 components? And perhaps someone has some 
handy tips for storing these things?


Just for kicks, I'm also building a 'cool-oven', i.e. a styrofoam box 
with a Peltier-equipped separation in the middle. The top half will be 
the hot side, with a temperature of 60°C (the oven part), and the bottom 
some 5°C (the cooling part). The cool section is used for storing a 
small jar of solder paste, and the warm section can be used for baking 
moisture sensitive components.

Would this work? Or is just heating up the stuff not enough, and do I 
need to lower the moisture level in the air as well? (Perhaps this can 
be as simple as creating a small air flow from the cool part to the hot 
part...)


Any thoughts are appreciated!

Best regards,

Richard Rasker


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