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TDA4VEN-Q1: PCB hole in plate

Biao Li
Expert 6440 points
Part Number: TDA4VEN-Q1

Tool/software:

Hi Expert,

Customers reported that there are many 0201 decoupling capacitors on the back of our EVM using vias in the pad. Their factory has many concerns about this, as follows:

We are currently using POFV (resin plug hole + electroplating filling) + immersion gold process, but the electroplating flatness does not meet the welding requirements of 0201 devices; 0201 devices have small pads and low steel mesh thickness, and uneven electroplating of the holes in the pad has a great impact on it, which may cause cold soldering problems and cannot guarantee long-term reliability.

do you think this concern is make sense to you? do you have any suggestion to them?

BR,

Biao 

  • 0
    TI__Guru 52225 points

    These questions should be targeted to PCB board manufacturers and their capabilities.  The PCB manufacturers that we have worked with for EVM development have not stress any concern with the number and location of the 0201 devices and the relative locations of the vias (in pad). 

    Note the design can be adjusted to meet different manufacturing needs.  In this case - care needs to be take to ensure the low inductance paths for the decoupling capacitors. One possible options is to move some capacitors to top layer, just outside the perimeter of the processor.  Assuming the dedicated power layers are near the processor, the shorter via travels can help offset the farther capacitor locations.

  • 0 in reply to Robert Eschler
    TI__Expert 6440 points

    Hi Robert,

    Can you provide us with the design requirements for the vias(in pad) of the 0201 CAP on the EVM PCB board?

     As for the diameter of the vias, the Maximum filled via depression(dimple) & filled via protrusion(bump),in um.

    BR,

    Biao

  • 0 in reply to Biao Li
    TI__Guru 52225 points

    The vias used on the EVM are 18mil pad with 8mil drill (or 457.2um pad with 203.2um drill).  I do not have specifics on the PCB process used to fill the via, plate, and planarize the pad.  I think that is specific for each PCB manufacturer.