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TSemk.1
Associate
February 13, 2023
Solved

In the LPS22HB datasheet , there is a statement " The package is holed to allow external pressure to reach the sensing element." Is there a hole somewhere in the part package that should not be covered up, and should be kept clear of obstructions?

  • February 13, 2023
  • 5 replies
  • 1673 views

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    This topic has been closed for replies.
    Best answer by S.Ma

    Usually if the hole is not done on the plastic package, it is very small on the silicon exposed cap area of the package. Pressure doesn't need a "big" hole. Humidity sensors do as humidity is like a cloud, needs movement... a fan ideally.

    5 replies

    OSell.1
    Associate II
    February 14, 2023

    This is a good question. I went to google and looked at the images of some of these sensors. I didn't see any crazy obvious holes in the package. But based on what is typical for these types of pressure sensors and what I saw. I believe it is likely on the top where the window is.

    S.Ma
    S.MaBest answer
    Principal
    February 14, 2023

    Usually if the hole is not done on the plastic package, it is very small on the silicon exposed cap area of the package. Pressure doesn't need a "big" hole. Humidity sensors do as humidity is like a cloud, needs movement... a fan ideally.

    Eleon BORLINI
    ST Employee
    February 14, 2023

    Hi,

    @S.Ma​  is right, you can have a look to this picture

    0693W00000YAiAzQAL.png-Eleon

    TSemk.1
    TSemk.1Author
    Associate
    February 14, 2023

    Thanks for the information. These are extremely small diameter holes barely seen under my microscope. So I assume the MEMs diaphragm is somewhere in the cavity below the "silver foil" cover with the 6 holes? ( I originally maybe wrongly assumed that the silver foil was not holed and was the diaphragm that flexed with changes in the atmosphere pressure).

    Eleon BORLINI
    ST Employee
    February 14, 2023

    Hi @TSemk.1​ ,

    correct (the silver foil is actually a silicon cap)

    -Eleon