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SN74LVC2G08: Land Pattern for DCT (R-PDSO-G8)

Martin_TFS
Prodigy 20 points
Part Number: SN74LVC2G08

Hello,

lately we have quality issues concerning the the solder joints of the SN74LVC2G08. We use the package DCT (R-PDSO-G8)

The recommended land pattern for this package is defined as follows.

Our assembly service noted that the solder pads reach beneath the IC package and

in addition that the standoff between the IC package and the PCB is very small.

We have built our assembly for many years without problems, so my question is

- Has there been a change to the IC package?

- Is there an updated land pattern avaiilable?

  • 0
    TI__Mastermind 24975 points
    Hello,

    Please find a link below to the DCT packag mechanical drawing.
    www.ti.com/.../mpds049b.pdf

    You can find parts by package at the link below, and then click on the PDF link that shows on the right side of the page to see the mechanical package drawing for that device: www.ti.com/.../searchproductbypackage.tsp

    This is the same drawing that is used for all TI devices in the DCT package. There have not been any changes to the package recently.

    Best,
    Michael
  • 0 in reply to Michael J Schultis
    Prodigy 20 points

    Hello Michael,

    thanks for your feedback to the package. My second question was concerning the land pattern for the DCTpackage as shown e.g. in the SN74LVC2G08 data sheet or the corresponding bxl Ultra Librarian file.

    The recommended land pattern suggest that the pads reach beneath the IC package, but the IC package allows an gap between 0.0 and 0.1mm. (see picture)

    Our EMS claims that this pad design leads to poor solder joints, because the plastic package rests on the solder paste, which is comprehensible for me.

    We could use smaller solder pads that don't reach beneath the part, but usually we stick to the land pattern provided by the manufacturer.

    So I just wanted some feddback from TI concerning this issue.

    Best regards

    Martin

  • 0 in reply to Martin_TFS
    TI__Mastermind 24975 points
    Hello Martin,

    Our file is the suggested landing pattern and should work, but if it is causing issues for manufacturability, then I would recommended fixing it in your landing pattern layout.

    Best,
    Michael