CAUTION: moisture sensitive devices WTF??

Discussion in 'General Electronics Chat' started by arthur92710, Sep 17, 2007.

  1. arthur92710

    Thread Starter Active Member

    Jun 25, 2007
    307
    1
    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!!!!???????!?!??!
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    What are the devices? It may just be that they might deteriorate under humid conditions.
     
  3. arthur92710

    Thread Starter Active Member

    Jun 25, 2007
    307
    1
    THE first one is CY7C9915JXI-5 the second one is CY8CLED04-68LFXI 10 in each
     
  4. Distort10n

    Active Member

    Dec 25, 2006
    429
    1
    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
     
  5. arthur92710

    Thread Starter Active Member

    Jun 25, 2007
    307
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    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?
     
  6. Distort10n

    Active Member

    Dec 25, 2006
    429
    1
    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.
     
  7. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
    10
    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
     
  8. arthur92710

    Thread Starter Active Member

    Jun 25, 2007
    307
    1
    it was a sample from cypress. its completely useless its smd and has many small pins. They have sent good stuff before :)
     
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