• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 30 subscribers
  • Views 255 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.

HDC3020-Q1: abnormal 90% humidity

Ryan Wang
Expert 7425 points
Part Number: HDC3020-Q1
Other Parts Discussed in Thread: HDC3020,

Dear expert,

Customer mass production environment normal humidity is 42%. They control max humidity within 75% max. They put 90% as limitation for production error report which is very relaxed condition.

NO error report is triggered during last 10Ku manufacture. But on Mar. 5, 60pcs HDC3020 report over 90% humidity among 600pcs manufacture. After this, they stop mass production.

They picked 6pcs among 60 pcs to do below test:

1. Redo measurement, these 6pcs report value varied. Sometimes, they report 100%. Sometimes, they report 0%.

2. Bake these 6 pcs HDC3020 boards at 50C for 10min, then take measurement after board cool down. They all report 42% humidity (correct value) within 1 hour. After 4 hour, they measure gain. They all report over 90% abnormal data again.

3. Bake these 6 pcs HDC3020 boards at 85C for 7 hours, then take measurement after board cool down. They all report 42% humidity (correct value) within 26 hours. 

This is a critical production stop issue. Need your great help on this.

  • 0
    TI__Genius 11885 points

    Ryan,

    For the other 540pcs of HDC3020-Q1, did those all read 42% without issue (plus or minus a couple %RH)? Were all 600 pcs from the same lot or reel? I want to know any potential differences between these 60pcs and the other 540 that were fine.

    Another question, the 60pcs that failed the 90% check, did they all read 100% or some RH value between 90% and 100%?

    Based on your comment that the 6pcs sometimes read 100%, sometimes read 0%, I am thinking there could be some liquid in the sensor area. Was this observed, or is then even possible on the assembly setup? We have seen that liquid in the sensor area can cause abnormal 100% and 0% readings.

    Did temperature readings ever have any issue?

    It is good to hear that baking at 85C for 7 hours seems to correct the parts, and they haven't started failing again so far. This leads me to thinking that there was some sort of liquid in the sensor area, since the 85C may have been enough to dry it out.

    How are these devices being soldered? Customers must use no-clean flux (and then not clean it off), they cannot use water soluble flux (with or without wash). 

    Lastly, if possible, please provide some zoomed in pictures of the sensor area on the affected parts (before or after bake, whatever you can get). I may be able to see in the sensor area if there is a clear piece of debris or water spots.

    Thank you

    -Alex Thompson