By using Spec Definitions in Name Value Pair Definitions it is possible to cross check entered values (or calculated values based on entered values) with Part Specifications. E.g. you have a General Measurement Step Definition, that is used for different products (Each product has a different Part Definition). The result of the measurement should be checked with the specifications of the part to determine if the Traveler can continue or not. One possible implementation is to use Input - Output specific data entries for which you define process specifications

An other possible implementation is to use Spec Definitions. A step by step example is given below. The following steps will be discussed:

  • Step 1: Define the Spec Definition and the Spec Value on the Product Definition
  • Step 2: Add the value you want to check and create a PASS / FAIL value
  • Step 3: Define the attributes of the PASS / FAIL condition
  • In the last section we will take a look how the configuration will act on the Traveler

Define the Spec Definition and the Spec Value

To create a data entry that is checked with a product spec, take the following steps:

  1. Create a Spec Definition. A single Spec Definition can be used for multiple Part Definitions. (E.g. A Wafer thickness measument. The same Step Definition can be used for different Wafer types with different specified Wafer thickenesses)
  2. Attach the Spec Definition to a Part Definition on the Specification Tab on the Part Definition Dialog. When the Spec Definition is attached, a spec value can be assigned for this specific Product.

The figure below is showing Min and Max Thickness Specs for Wafer Part Definition WFR-01 Rev A (Other Wafers with different Part Definitions can have different max and min values, but still use the same Spec Definitions):


In this case 'WFR-01 Rev A' has a value of 280 for the 'Wafer Thickness Maximum (275 um)' Spec Definition, and a value of 270 for the 'Wafer Thickness Minimum (275 um)' Spec Definition.

Create Data Entries for the Wafer Thickness Check

After creating the spec values on the Part Definition the Name Value Pair can be defined. Below an example is given for the 'Average Wafer thickness' which is the result of 5 measurement values that are entered by the Operator.

First a Step Definition has to be created that is used to measure the Wafer Thickness (TEST-01 Rev A). On this Step Definition the Data Entries for the thickness measurement can be defined. Using a Calculated Data Entry the 'Average Wafer Thickness' value can be determined.

The following figure show how the create a PASS / FAIL value for the 'Average Wafer Thickness'. This value is a Calculated Data Entry as well.

Adding the calculated value that has to be Check to the calculated Spec value check

First you have to add the PASS / FAIL value to the list of Name-Value Pairs before you can start editing the attributes that are used to access the Spec Values.

Add in the Spec Values and the Condition

After the PASS / FAIL Name Value Pair is added to the listbox the Name-Value Pair can be clicked to open the Name-Value Pair Dialog. This dialog is shown in the following figure:

Adding the calculated value that has to be Check to the calculated Spec value check

The Spec Values can be added by Selecting the Spec Definitions for the 'Variable SP' pulldown, assigning a name to them and add them to the 'Variable(s)' list by clicking the plus sign.

The following expression is used to assign a 'PASS' text value or an 'FAIL' text value to the 'PASS / FAIL' field

IFF([A]>[C], 'FAIL', IIF([A]<[B], 'FAIL', 'PASS'))


  • [A] = TEST-01: Average Wafer Thickness
  • [B] = Spec: SP-002 Min Wafer Thickness [um]
  • [C] = Spec: SP-001 Max Wafer Thickness [um]

If the resulting value equals to 'PASS' the Traveler will be able to continue to the next step.

How it Works out on the Traveler

The following figure shows how the configuration for the check on Spec Values will work out on a Traveler:

Adding the calculated value that has to be Check to the calculated Spec value check

In this case the calculated 'Average Wafer Thickness' does not meet the minimum value requirement of 450 micron. So the operator is notified at the moment she wants to move the Traveler to the next step.

Useful Links

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