CAUTION: moisture sensitive devices WTF??

Thread Starter

arthur92710

Joined Jun 25, 2007
307
I just received some parts and it says level 3 moisture sensitive devices. DO NOT OPEN EXCEPT UNDER CONTROLLED CONDITIONS.

WHAT DO I DO?!!?

It says exposure time 8 hours and 15 min

It says some thing about baking it. Will baking it do some thing to it? Does it want a cake or st?:p
also it says plating material SnBi (Tim and Bismuth)

Should I throw them in the oven for 24 hours at 125*C?

PS!! There are 2 of them!!! One was in a long box and one is in a wide box. I opend one and now i wat to open the other one but it says 4 HOURS ONLY!!! This one has NiPdAu Nickel Palladium Gold

WHAT DO I DO!!!!???????!?!??!
 

Distort10n

Joined Dec 25, 2006
429
If the bag states that the floor life is 4 hours for one part and ~8 hours for the other part, then it sounds like a Moisture Sensitivity Level (MSL) of 6. This means that the molding compound used, and the size of the device affect how well moisture is absorbed into the package.
During solder reflow these packages can be exposed to sudden and very high temperatures which will cause mechanical defects in the device. Most of the time the part will actually crack under the mechanical stress.
So you do have to bake the devices in an oven, but not starting out at 125°C. Devices have reflow profile where the temperature is slowly ramped up to the peak temperature over a period of hours.

It is a JEDEC standard:

http://www.jedec.org/download/search/jstd020c.pdf
 

Thread Starter

arthur92710

Joined Jun 25, 2007
307
So first I put them into an toster oven at 48 then 54 then 65 then 93 then 120 and then 125? and they will work like normal componants?
 

Distort10n

Joined Dec 25, 2006
429
I have no idea about the reflow profile. The manufacture of the chip will have to tell you that, unless the reflow profile in the JEDEC document literally is the standard reflow model.
MSL is a science in itself. I would imagine that if you were going to painstakenly hand solder the leads to a PCB, then I do not believe that you need to pay attention to the MSL ratings.
They are concerned with the moisture in the package. Wave soldering for example would vaporize any moisture in the package, and cause mechnical damage; e.g., cracking of the plastic package. I doubt hand soldering SMT leads would do that.
 

bloguetronica

Joined Apr 27, 2007
1,372
Strange. I didn't quite understood what kind of device it is. Never saw a moisture sensitive moisture device. What sort of cake...err...device is it? An extraterrestrial one?:D
 
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