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UA78L: Coefficient of Thermal Expansion (CTE) for Part Number UA78L05AIPK

Part Number: UA78L

I am working on a solder joint fatigue analysis for a board that uses a lot of TI parts.  Can you please tell me the coefficient of thermal expansion (CTE) for part number UA78L05AIPK ?

Thanks in advance for your help!

  • Hi David,

    Can you use the material content for the regulator for your analysis? If so our material content search allows you to find this information for any of our devices. 

    Here is the material content information specific to the UA78L05AIPK 

  • I suspect that it's theoretically possible to determine the CTE of something given a detailed material breakdown and geometry, but that's way beyond my capabilities, and I've never seen it attempted for any but the simplest materials.

    I was hoping that test data would exist (some manufacturers test for this), or that someone very familiar with the construction of the part could identify a material whose influence would dominate.

    For a part with leads, the CTE of the leadframe tends to dominate, but this is not true for leadless parts.  The part I am asking about here has no leads.

    Could you possibly check with your packaging people?  They are the ones most likely to have this information.

    Thanks!

  • Hey David,

    Before we proceed I want to make sure we are aligned on the package because UA78L05AIPK comes in the SOT-89 package which is a leaded. Our packaging team is broken organized by the type of package, so I want to make sure I reach out to the right people about the right package. 

    I do know that doing a full blown model usually takes 2-3 weeks (probably better to assume it'll be on the long side due to the upcoming holidays), but we can probably get you a good estimate in a much shorter time based on the leadframe/mold compound being the dominant factors in the CTE. So let me know what you'd prefer and we'll work to get it for you.   

  • I took another look, and you are right -- it is leaded.  I'm kind of embarrassed now, because I don't think I should have been wasting your time.  I already have pretty good information on the CTE of typical TI leaded parts, and I can use your website to get specific material content information on the leadframe.

    I have a long list of parts I need to check, and I classified this one incorrectly.

    So -- I appreciate the effort and apologize for wasting your time.