Sorting Wires by Tiers

What is a Tier? - When wire bonding a package the wires are grouped into tiers. Each group of wires that share the same approximate length and start/end locations can be bonded using a common loop height. For example, wires bonded to the paddle are typically about 1500-2000 um long and use a low loop height.

Wires going to the fingers may be 3000-4500 um long and use a higher loop height. When bonding it is necessary to program the machine by tiers (i.e. all wires with a common tier/loop height are bonded in one pass); then the next group of wires is bonded and so on.

Wirebond's OLP Wire routine solves the problem in seconds. The user starts the routine, specifies the wire layer(s), and tells the routine to scan the wires.

Using a sophisticated sorting routine derived from the convex hull algorithm, OLP Wires determines which wires are grouped into a common tier. It then enables the user to define a layer and layer color for each tier. Finally it moves the wires to the appropriate layer.

Example

We want wires attached to the ground ring grouped on a single layer; wires attached to the power ring grouped together and wires bonded to the fingers grouped into a third layer. Each layer should be assigned its own color.

To sort the wires by tier open the OLP Wires dialog box as shown at left. Select the AutoCAD layer that holds the wires. Then press the Scan button.

In a few seconds, the OLP Wires routine has analyzed the wires and segregated them into tiers. You can now set the layer name and color for each tier. Once done, press OK and the wires will be moved to the new layer and assigned the new color.