Hardware Reference
In-Depth Information
b
x
Upper left subarray
Upper right subarray
a
Routing
ring for
Pin
P
Routing
ring for
Pin
2
…
…
Routing
ring for
Pin
1
y
Lower left subarray
Lower right subarray
c
x
Routing ring for
Pin 1
d
Via
Routing wire
T
w
T
bw
Via
D
via
Routing
wires
Electrodes that are
assigned to
Pin 1
Electrode
y
D
Fig. 7.2
(
a
) An electrode array and “routing rings” for Pins 1 to P ;(
b
) a large electrode array that
is partitioned into four parts. The wire routing solution for these parts can be derived separately;
(
c
)
top view
of an electrode sub-array and the underneath routing wires on the direction which is
parallel with one edge of the array; (
d
)
top view
of an electrode and the underneath routing wires
3.
Connecting electrodes to routing rings.
Based on the pin-assignment configu-
ration, electrodes are connected to their corresponding routing rings. An example
is as follows. We assume that the electrode array shown in Fig.
7.2
c is the upper
left sub-array of the electrode array shown in Fig.
7.2
b. In this sub-array, three
electrodes are assigned to be connected to Pin 1. The vias at the centers of
these three electrodes electrically connect the electrodes to three routing wires.
As shown in Fig.
7.2
c, routing wires of these three electrodes intersect with the
routing ring for Pin 1. At these crosspoints, vias are added to electrically connect
the routing wires with the routing ring for Pin 1. Using this method, all the
electrodes that are assigned to Pin 1 are connected to the routing ring for Pin 1.
In the similar manner, all electrodes that are assigned to Pin p (1
p
P )
are connected to the routing ring for Pin p. In order to simplify the wire-routing
solution and to avoid any interference between two metal wires on the two-metal-
layer biochip, all routing wires are aligned parallel to the edge of the electrode
array (in either the direction of x-axis or y-axis), as shown in Fig.
7.2
c.
