Net(z)test
Creating Network Test Programs
1. Introduction
2. Specification
3. Operating Instructions
3.a The Startup menu
3.b The Data Source menu
3.c The Info menu
3.d Procedure
4. Protection and Copyright
1. Introduction
The increasing utilization of Flying Probe testers in production tests because of its advantages over the in-circuit test make the testing time for the Flying Probe tester a critical economic factor. No adapter costs, short conversion times for module redesign, fast test program generation and minimal test pad size requirements are strong arguments in favor of the Flying Probe tester for average quantities (of approx. 10,000 units). Both the time-to-market and the total costs are lower than for the in-circuit test. The sequential execution of the measuring steps and, consequently, the testing time are critical success factors.
A new product developed by Siemens - Net(z)test has just entered the arena. It improves on the performance of the Flying Probe tester, reducing the testing time by between factor 3 and factor 7, while at the same time maintaining existing levels of accuracy and in some cases even improving accuracy. The test method for Flying Probe testers was piloted with a number of customers in the period 1994-1998 in over 100 test programs and can thus be regarded as stable.
The APT8400 Flying Probe tester has for many years been one of the most popular tools in its class. With its extremely high MTBF and robustness, this product never fails to make the grade in test departments and laboratories. This tester is particularly well placed to meet requirements for production faults with small quantities of components (prototype test). Its ability to measure capacities with great accuracy (up to the pico-farad range) makes it the method of choice for network testing.
The Net(z)test software tool is used to generate test programs that reduce
the testing time by a factor of between 3 and 7 and also contribute to
an increase in test accuracy (e.g. all SHORTS, irrespective of the distance
between the networks involved). It is possible to implement existing standard
programs in Net(z)test, as well as create it from design data that was
generated with Fabmaster or another software tool in UNICAM format. Net(z)test
programs are created on the basis of Patent No.: 97E2412, held
by Mr. Antun Vuksic of SIEMENS AG (ATD TD MCH 8)
The product can be used on all PCs with a 32-bit Microsoft operating system.
As a prerequisite for the generation of a Net(z)test program, a conventional
test program must be generated in CA8 format with Fabmaster or UNICAM.
2. Specification
The measuring method used by Net(z)test is based on the observation that the conventional generation of test programs using Fabmaster or UNICAM usually involves multiple network contacts made via its test points (channels). This is necessary given the assumption that each component should be checked via its contacts. This involves a great deal of repetition that is unnecessary for measurement purposes.
NET(Z)TEST: METHOD FOR REDUCING THE TESTING TIME AND IMPROVING FAULT COVERAGE
With a conventional test program, each component has its electrical properties checked individually, and measurement points are consequently accessed several times. With Net(z)test, on the other hand, the electrical properties of the network are ascertained locally in a measurement operation involving multiple measurements. This guarantees that a measurement point will only be accessed once.
With Net(z)test, the number of contacts and, therefore, the testing time is reduced by a factor of between 3 and 7. This controls the number of contacts.
With a conventional test program, adjacent networks are checked for shorts. With Net(z)test, shorts are also detected in remote networks using the above method by changing the properties of the electrical networks. This leads to improved fault coverage in relation to SHORTs between any two lines.
Improved fault coverage is also achieved in relation to IC-OPEN if internal impedance (R, C) can be quantified. An improvement in fault coverage is also possible in relation to line interrupts.
The element test is streamlined considerably by reducing the test to
basic test steps. Short and open measurements are carried out in relation
to electrical networks.
NET(Z)TEST: METHOD FOR DETERMINING ELECTRICAL PROPERTIES
The electrical network measurements are taken in relation to potential (or potentials). The networks that are connected directly with one of the potentials are examined separately. In Net(z)test, the test steps are executed in relation to either REF-KANAL-GND (default) or REF-KANAL-VCC (for networks with a link via a discrete component with VCC). Elements without a potential connection are examined separately in the element test.
If only one reference channel is to be used for both cases, both entries must be identical. A number of linear and non-linear measurements are taken to ascertain the electrical properties of the network.
A maximum of 5 test steps are carried out in relation to the reference network for each network.
Depending on whether or not a discrete component is used to form the connection to the potential, either resistance is measured or a high resistance test is carried out on the network.
Test step 2: D test. Diode measurements
A diode measurement is taken as a second measurement. A second diode measurement may be advisable to protect against polarity reversal.
Test step 2a: D test. Diode measurements
This test step is introduced to use asymmetrical characteristics to protect against polarity reversal (anti-parallel diodes).
Test step 3: C test. Capacitance measurement
Used where a discrete capacitance is measured. If this is not available, the line capacitance is defined.
Test step 3a: C test. Capacitance measurement
This is not normally active and is used as a reserve. An example of the application of test step 4 is the measurement of the lower C limit for line capacitance. This allows, under certain conditions, an improvement in test accuracy in relation to the fault types "line interrupt" and "OPEN".
3. Operating Instructions
Net(z)test is a program for the generation of test programs for the Flying Probe tester. Net(z)test programs are created on the basis of the Net(z)test method patented by SIEMENS AG.
The product can be used on all PCs with a 32-bit Microsoft operating system. As a prerequisite for the generation of a Net(z)test program, a conventional test program must be generated in CA8 format with Fabmaster or UNICAM.
3.a. The Startup Menu
3.a.1. The Startup Menu: Defining a New Project
When the tool is opened, certain general requirements must be met in order to initialize execution. It is possible to define the parameters in a project and therefore start a second execution of the routine without having to re-enter the data. When the routine is executed again, the parameters stored in the project are retrieved and only the parameters that are to be modified need be re-entered.
To enter new default values, you must select the menu item New from the File menu to create a new project or select Open to open an existing one. Each project can be saved with its parameters in a file with the ending *.net. When you create a new project, the Project Wizard is started automatically as soon as you select New and the parameters can then be defined as described in 3.b.).
| Menu | Notes |
| Comment | When creating a project, the general requirements (new project or open project) must be met. The basic format can be selected with the menu item. |
| Toolbar | For customizing the display to suit your own requirements. |
| View | Adds different viewers to the tool, to which specific functionality can then be assigned. |
| Help | Online Help |
3.b. The Project Wizard
3.b.1. The Project Wizard: Data Source
All project-specific data is entered in the Project Wizard. Note that the first tab must be filled in completely in order to be able to use the Wizard properly. This first sheet of properties describes the data source. There are various buttons available to help you make your input. (Browser: for defining the path and name of the file; Viewer: for checking the selected file).
Define the Format
Parameter for the data format used. You must toggle between the options and the side that is not grayed out is selected.
Bottom
Parameter for the data source type (double-sided or single-sided test program). You must toggle between the options and the side that is not grayed out is selected.
Open
Name and path for the file in question. The name and path can be defined quickly and easily by means of the Browser function. You can also examine the data with the Viewer option.
Net(z)test
Definition of the name and path for the file in question. The name and path can be defined quickly and easily by means of the Browser function.
Once you have finished entering the project data you must click the Load button to verify the project data selection and apply the data.
3.b.2. The Project Wizard: Measurements Tab
In the Project Wizard you can adapt the properties of the Net(z)test
measurements to suit your own requirements. The second sheet of properties
contains check boxes for selecting the types of measurements that are
to be taken. A set of default measurements is defined that corresponds
to the typical settings for Net(z)test and matches the attached table
for debugging. The default values for each individual measurement are
defined using the Property button.
The individual measurements are determined from functionality, reference
value and, where necessary, from the tolerance range.
3.b.3. The Project Wizard: Comment Tab
In the Project Wizard you can use the comment fields to specify the elements that are to be included in the component test, but which were not included in the Net(z)test test program component test based on the tool criteria.
If, for example, the component named "V104" is not included,
the identifier can either be entered directly in the "Type"
field or, if multiple components are to be specified using a systematic
identifier relationship, it can be partially qualified. In other words,
"V10" can be entered in the "Type" field for all elements
beginning with "V10..." that are to be included.
To save effort it is recommended that you assign all discrete components
an electrical reference value and thus improve the tool's ability to recognize
them.
3.b.4. The Project Wizard : Potential Tab
In the Project Wizard you must define reference potentials for the Net(z)test measurements. A list box - which uses the data from the first tab - is displayed for selecting the network name and the corresponding test pad, represented by the channel numbers.
One or more potential pairs are specified, depending on the module type. Multiple potentials are only necessary for modules that have groups of components, which are isolated from other groupings. When a combination of reference potentials is specified for the Net(z)test test program, the following selection lists are made available.
Select from Net
Clicking this button updates the contents of the list box and loads the complete network names list. A combination of reference potentials can be specified for the Net(z)test test program.
Select from Channel
Clicking this button updates the contents of the list box and loads the complete list of channels belonging to a network.
Add
Clicking this button adds the network pairs selected in the list boxes to the list of reference potentials.
<< >>
These buttons are used to navigate in the list of reference potentials that has been created using "Add".
Delete
When you are navigating in the list of reference potentials using the navigation buttons described above, a selected potential pairing can be removed from the list by clicking the "Delete" button. You can do this for as long as all pairings can be removed from the list.
If no reference potential is selected, using Net(z)test will be completely meaningless. The selection of a reference potential is therefore mandatory, not optional.
You can exit the Wizard once tabs 1-4 have been completed.
3.c. The Project Menu
3.c.1. The Project Menu: Creating the Project
When the tool is opened, certain general requirements must be met in order to initialize execution.
| Menu item | Shortcut | Description |
| Comment | Ctrl+S | In order to be able to uniquely identify individual components, a uniquely distinguishing characteristic must first be initialized. The Zener, LED and elementary diode components can be identified by interpreting the Comment Source. Specify your identification element. Use the same procedure for transistors. Partial specifications can also be used, which do not necessarily have to be used to represent the beginning of the Comment Source.e.g. |
| Reference Potential | Ctrl+B | Specify the ãVCCä or ãGroundä channel. If the data has already been defined, it can be added to the list box contents by clicking the relevant button. |
| Create | Ctrl+E | This menu item initializes actual creation of the test program. The data cannot be viewed until this menu item is selected (see the next point). |
| View Data | Ctrl+R | This menu item cannot be selected until ãCreateä has been executed. It analyzes the data available and displays the result. |
3.c.2 The Info Menu: Help Functions and Version Information
The program has a Help file. By calling this function you can obtain Help for this particular program, or you can access the entire Help system provided by the operating system.
The menu item Version displays version and copyright information.
3.d. Procedure: Parameter Input
When the tool is opened, certain general requirements must be met in order to initialize execution.
- The files containing the data for the required procedure (Unicam or
Fabmaster) should first be specified.
For the FABMSTER format you must select the following: the NAILCHECK.ASC file, the LABELIST.ASC file and the measurement program that is to be adapted.
For the UNICAM format you must select the following: the APT8400.NOP file, the Nailasgn.rep file and the measurement program that is to be adapted.
- To specify the file you must select either the FABMASTER or UNICAM
menu item from the Options menu. The FABMASTER / UNICAM dialog box is
then displayed.
The paths and files described earlier are specified here. By clicking the "View" button you can check the contents of each of the files.
The comment type is selected using the radio button in the bottom section of the dialog box.
If the dialog box does not contain any default values you are prompted to enter the required values.
- The reference channels for VCC and GND must now be specified.
This is done by calling the "Data" menu item and "Reference Potential" submenu item.
The "Potential" dialog box is displayed, in which you can enter the channels.
- Now you need to enter the identification elements for discrete components
such as diodes, Zener diodes, LEDs, PNP and NPN transistors.
The program "learns" the input in the list boxes, i.e. your input is saved and is displayed in the list box again the next time you call the function.
- You can now initiate generation of the test program by selecting
the menu item "Create Data Sources" or by clicking the corresponding
button in the toolbar. A message is displayed in the terminal window
to tell you once the operation has been completed.
- Finally, an SD8 file for the Takaya Flying Probe tester can be created using the Ca8 converter. The toolbar contains only one function for this purpose.
4. Protection and Copyright
The Net(z)test principle is based on the Siemens patent No. 97E2412, registered by Mr. Antun Vuksic.
Information contained in this document may only be used with the permission of the patent holder. The software is supplied with a Sentinel dongle, thereby restricting the license to one installation only.