Re: req:question on pcb
The package stub consists of all the pieces that connect an integrated circuit die to the outside world through the IC package - the bonding pad, the bonding wire, the internal pin connection, and the external IC pin. It is taken into account when you do a distributed model of the IC. See the following for a definition of distributed model.
There are two ways you can model an electronic circuit - lumped and distributed.
The lumped model assumes that the device you are modeling is a black box with two terminals, and there is one inductance, resistance, and capacitance across the terminals that represent what is seen by the connected circuitry outside the black box - for the purpose of modeling, you don't care what is inside the box, only how it looks to the connected circuitry.
The distributed model is more detailed and looks beyond the connected terminals to describe the behavior of the black box itself. An example would be a section of transmission line - you can describe it as one specific impedance as you look into the two terminals of the transmission line (lumped model), or you can describe it as a series of connected series inductors, series resistors, parallel resistors and parallel capacitors. You then analyze what happens as a wavefront moves down the line through the distributed matrix of those equivalent component parts. Distributed modeling can also be considered piecewise modeling - representation of each small segment by an equivalent network of discrete component parts.