Define Process Variables

Formula process variables correspond to all the process variable formula parameters defined for the phases used in the construction of the recipe.

When you construct a procedure, you can use the same phase more than once. If you use the same phase more than once, the associated process variable parameters are used as many times as the phase is used. Because of this usage, the parameter names are listed in the Process Variables dialog box more than once. To prevent confusion when viewing the list, you can change the process variable names so that they are more descriptive. Changing variable names so that they are more descriptive affects only the specific instance of the parameter in the recipe Also, as you build the procedure, you can change the names.

To define process variables

1. Open the Recipe Editor.

2. On the Edit menu, click Process Variables.

   Note: Do not change the Tolerances for Discrete, String, and Enumeration type process variable formula parameters.

   The Process Variables dialog box appears.

   The list shows all the process variables used in the phases of the recipe procedure. The list is empty until you use phases that contain process variable parameters in the recipe procedure. After recipe procedure creation, you can change the process variable parameter in the Process Variables dialog box or directly in the specific phase.

   For each process variable that appears in the list, the phase Type, Name, Value, Tolerances, and Description are shown. This information is derived from the Process Model database.

   

3. Select a process variable from the list.

4. In the Name box, type an appropriate name (16 characters maximum).

5. In the Value text box, type an appropriate value.

   Note: The Value must be within the range of the High and Low Limit values defined for the parameter in the Process Model database.

6. Select an item from the Tolerances list.

7. In the High Deviation and Low Deviation boxes, type values that are consistent with the tolerance that you selected.

8. Click Change.