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MSL Not Applicable to Hermetic Packages

         

Hermetic packages, being more expensive, are produced in much lower volumes than plastic packages.  They are often used in mission-critical applications such as military and aerospace devices. For less critical applications, plastic packaging for IC's would usually suffice.  Because hermetic packages are not produced in large volumes and because not all factories produce hermetic IC's, many new engineers are not familiar with the different types of hermetic packages and their characteristics.  The archived forum thread below tackles what hermetic packages are, and clarifies why MSL classification is not applicable to hermetic packages. 

 

Posted by Mike_balbuena: Sat Oct 28, 2006 8:30 am    Post subject: MSL for Ceramic packages

 

Can anyone provide me information on what MSL levels for various parts packaged in ceramic. Parts like CSOIC, CQFP etc. I've seen Amkor make most of this but could not find MSL.

Thanks,
mike
_________________
Mike B.
 

Posted by FARel Engr: Mon Oct 30, 2006 5:54 am    Post subject:

 

Hi Mike, MSL classification is only applicable to plastic packages. Ceramic packages should be hermetic, and are therefore not subject to moisture-related package cracking phenomena during reflow.

FARel Engr
 

Posted by Mike_balbuena: Mon Oct 30, 2006 11:07 pm    Post subject: MSL

 

Thanks FA Rel
_________________
Mike B.
 

Posted by Batang_XP: Thu Nov 16, 2006 1:38 pm    Post subject:

 

Can someone elaborate what HERMETIC is? Is it a type/classification of materials? Which material in IC packaging?
Sorry, newbie po ako.

regards,
Batang_XP
 

Posted by Mike_balbuena: Thu Nov 23, 2006 5:07 am    Post subject: hermetic

 

It is a product characteristic sealed and airtight, resistant to external influence.
Some examples of Hermetic packages is ceramic packages and metal can.
_________________
Mike B.
 

Posted by Sebastian: Mon Mar 12, 2007 10:33 am    Post subject:

 

Hi,

Just additional info...

Hermetic packaging uses ceramic materials. The best example for this is Ceramic Dual-In-line (CDIP) pkg. Externally, it has the same appearance as its plastic counter part (PDIP) except that it is made of ceramic.

The main difference is the way it is packaged (or sealed). PDIPs are molded while CDIPs are glass sealed. It is composed of base and caps (both have preformed glass) and the die is placed on a "cavity" of the base. When sealed, the die and wires are "floating in the air" (for the lack of better word) and not molded. The preformed glass prevents the air/moisture from entering the pkg making it air tight (hence hermeticity).

This is done especially on EPROM devices where erasing and programming on the dice are needed which can't be done had molding been used.

regards...
 

Posted by Guest: Mon Mar 26, 2007 8:59 am    Post subject:

 

Hermetic packages can either be made of ceramic or metal. The ceramic types can be glass-sealed as described above or solder-sealed with lids. For more info, refer to http://www.EESemi.com/sealing.htm

      

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