X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f X-Recipient: geda-user AT delorie DOT com To: geda-user AT delorie DOT com From: "Richard Rasker (rasker AT linetec DOT nl) [via 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 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id w6BBqGWo009627 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