• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 321 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LP8758-E0: MECHANICAL HEIGHT TOLERANCES

CHRISTOPHER MA
Prodigy 30 points
Part Number: LP8758-E0


I noticed that the datasheet lists the x and y dimensions and their mechanical tolerances, however the thickness dimension only shows a 1 mm MAX dimension. What is the nominal and minimum height of this component?

  • 0
    Prodigy 30 points
    Sorry for the typo, the datasheet lists a max thickness dimension of 0.625 mm.
  • 0 in reply to CHRISTOPHER MA
    TI__Mastermind 49961 points

    Hi Mr. Ma,

      The max thickness dimension of 0.625 mm just gives the up limit only; the device has no nominal and minimum height measured.

  • 0 in reply to Phil Yi
    Prodigy 30 points
    Just curious, is there a height tolerance that we should assume? For example, if i need to design a thermal boss to this component and I don't know the minimum height of the component, I have no guarantee that the thermal boss will actually be in contact with the component. Perhaps it isn't on the datasheet, but there has to be some minimum height that the component is made to or else in theory you could put out a component that is 0.1 mm thick since it technically meets your mechanical drawing.
  • 0 in reply to CHRISTOPHER MA
    TI__Mastermind 49961 points
    Hi Mr. Ma,
    I've checked with our package team; the answer is that we normally just spec the maximum height because there are different process options available for a given pin/package designator combination that will result in different nominal values for height. Variations on UBM (thickness and diameter) , PI thickness, either if it is a RDL or a BOPCOA -to mention some examples, would result in a different nominal value. This variations would be device dependent so that would results in a lot of variations for the same drawing -or loose tolerances, if we include min/max values. So, we report the absolute max thickness possible.
    Getting this would imply getting the specific process details to this device, and wouldn’t recommend to include them in the package ePOD drawing since won’t be representative of all devices using the same package.
    A practical way in my experience is: using an adhesive thermal pad between your thermal boss and top surface of the device with the thermal pad's thickness can be push-pull a little bit.
    Let me know your comments and questions