RTI’s MultiTrace system is widely recognized as the most efficient way to curve trace large IC devices. The software easily configures for a wide range of test conditions over a wide range of IC packages. The first step in testing any device is to get an appropriate test fixture and setup files to enable its use on the test system. We will focus on the MTFixture program of the Multirace Suite software to create and reconfigure these setup files.

IC Types for MTFixture Setup Files

For this discussion, we will divide IC packages into 2 different types. First, there are array types like BGA, CSP, PGA, uPGA, and LGA which have pins names with alphanumeric names. Second, there are non-array types like SOIC, QFN, which are any devices where the pins are numbered with integers. For array types, we still need to number the pins with integers but after that, we can use the BGA names in the setup test conditions. RTI typically assigns pin 1 to the A1 pin and then numbers sequentially row by row to the bottom right pin.

Universal Arrays & DUT Boards (Fixtures for Setup Conditions)

Universal BGA socket with and without alignment plate

RTI’s universal BGA socket is a popular choice for array packages. The socket is populated to the highest pin count that the test system can support. For example, the MultiTrace with a PGA-625 fixture can support up to a 25×25 array. The MegaTrace with OctoPogo DUT boards can support up to 32×32 pin arrays. The MegaTrace can support more pins with a different interface.

We can use universal DUT boards and sockets for a range of packages having the same pitch. So, for example, the 25×25 array BGA socket can also hold a 16×16 array package, and a 10×10 CSP fixture can support a 5×5 package just as easily. In both cases, you will need custom alignment plates and lids, but these are far less costly than brand-new sockets.

DUT Boards & Setup Files

Side-by-side adapter board for PGA-625 fixture

When you purchase a DUT board from RTI, most times we can provide the setup files for the MultiTrace. This convenience reduces your effort in building setup files in the MultiTrace and is something only RTI can provide. For most adapters, the files consist of a pin-map file that defines which tester pin is being used and what number is assigned. A pin name file contains signal or BGA names correlating to the pin numbers, and, sometimes, a socket file enables the footprint view of the device in the Switch program. For non-array devices, the file sets are normally 1:1 and exactly match the device. For array devices, the PCB layout is typically more complex, and a complete file set is essential.

Reconfigure Setup Files with Master Socket File & MTFixture

Besides the reconfigurable sockets, RTI supplies reconfigurable setup files you can use to quickly prepare depopulated pin-maps of an array configuration to make the files exactly match your device. This process requires the Master Socket file and the MTFixture program.

We provide the master socket file with the fixture. The master socket file is initially created in a spreadsheet using the design net-list and correlation tables for the MultiTrace. After that, the process is all graphical.

How to Create and Reconfigure Setup Files with MTFixture

Step 1: Upon loading the master socket file in the program, the user is presented with a grid of dots representing available pins.

MTFixture program

MTFixture program

Step 2: The user sketches out the footprint of the device on the grid by shading cells the pins will occupy.

Highlighted Socket Footprint on MTFixture

Step 3: Using the built-in fill and number tools, the user enters pin numbers on the pin-map in order

Step 4: The user can automatically fill in BGA names using the pin names utility built-in.

Step 5: Using the same pin-map and saved pin names, the user saves the pin-maps in the library for use within the program (See MTFixture manual for complete instructions)

Creating and reconfiguring setup files for your sockets and adapter boards is easy with MTFixture. MultiTrace Suite offers a variety of other useful programs such as StdTrace which creates settings for SMUs and displays the data results on a graph screen; Switch which configures the switch matrix and status display program; MTForms which simplifies the process to configure StdTrace and Switch with fill-in-the-blank templates.

If you are interested to learn more about the programs of the MultiTrace, contact us to schedule a demo.