The wire's z-profile is defined using a model with parameters. While Artwork has developed some very sophisticated user-defined models, we are not going to use those at present - instead we are going to use two very old models developed by JEDEC - the JEDEC 3 point wire model and the JEDEC 4 point wire model.

Jedec 3 Point Wire Model

The JEDEC 3 point wire model requires just two parameters - h1, the height that the wire rises from the die pad and L1 the distance it travels horizontally before beginning a straight line descent to the package finger pad.

The three point model works well for relatively short wires. The illustration is not to scale as h1 and L1 are exaggerated for clarity.

Jedec 4 Point Wire Model

Longer wires generally have a bit of arc in them much like the arch of a bridge -- this helps to reduce the wire sag that might result in a short circuit. The JEDEC 4 point model has additional parameters that enable the user to approximate an arc as shown in the illustration below: