SN65LVDS311YFFR - About tolerance of package

Hello,

the tolerances are per ASME Y14.5M 1994.

I am working to get the exact number.

Regards.

Hello,

I've got feedback from the packaging team:

The 2.4mm is a "basic" dimension and shows the ideal distance between the centers of outside bumps.  The box underneath the bump dimension (the “feature control frame”) shows the tolerance of the bump positions from those ideal centers.  And it is a little complicated.  The center of each bump can independently vary within a circle of diameter .015 centered on the ideal center when the bump is as large as it can be, i.e., 0.30 mm diameter (“at maximum material condition (MMC)”).  As the size of the bump goes down you get a position tolerance “bonus” of the same amount, the positional tolerance gets bigger, but the net effect is that the outside edge of a maximally displaced ball remains in the same spot.  So in this case the furthest apart the centers of the outside balls could be at MMC is

2.40 + 0.015 = 2.415 mm,

and the furthest apart the outside edges of the two outside balls could be is

2.40 + 0.30 + .015 = 2.715. 

But if the balls are as small as they can be (“least material condition (LMC)”) in this case 0.20 mm diameter, then the size difference, MMC – LMC = bonus, is added to  the position tolerance and the centers can be

2.40 + (.015 + 0.10) = 2.515 mm

apart, but the furthest apart the outside edges of the balls can be is

2.40 + 0.20 + (.015 + 0.10) = 2.715 mm

exactly the same, which is the intention of this kind of dimensioning.

Hi,

Thank you for the information.

May I report the following contents to our customer? (Is our confirmation correct?)

The value of package size varies according to size of bump.

 If bump is 0.3mm(max), the package size is about 2.715mm.

 If bump is 0.2mm(min), the package size is about 2.515mm.

Therefore, cloud you please regard "2.8mm x 2.8mm " of datasheet(page1) mention as the maximum of the package of SN65LVDS311YFFR.

Regards, Kanemaru

Yes, I think you can tell 2.8mm is the max.

Regards.