Begin by defining a surface named Board for
the circuit board. Select Both sides in the prompt area to
specify that the surface is double-sided. In the
Model Tree,
double-click the Constraints container; define a tie
constraint named TopChip. Select
Board as the master surface and
TopChip as the slave node region. Toggle off
Tie rotational DOFs if applicable in the Edit
Constraint dialog box since only the effects of the chip masses are
of interest, and click OK. Yellow circles appear on the
model to represent the constraint. Similarly, create tie constraints named
MidChip and
BotChip for the middle and bottom chips.