Customer Solutions

Automating Semiconductor Chip Testing with LabVIEW

Author(s):

Wolfram Koerver, S.E.A. Datentechnik GmbH; Sven Petersen, S.E.A. Datentechnik GmbH

Industry:

Electronics

Product:

Data Acquisition, Fieldbus, LabVIEW, Vision

The Challenge:

Creating a system to identify possible failures of a semiconductor chip before beginning the production of high-quality, expensive semiconductor devices to reduce extraneous costs associated with manual testing.

The Solution:

Using National Instruments LabVIEW, multifunction data acquisition cards, and Fieldbus to develop, monitor, and control a system that automates the testing of semiconductor chips.

Testing Laser Diode Bars

Developing a Flexible and Accurate System
We developed a test machine, which can test multiple devices under test (DUTs) fixed on a submount. We perform the necessary characterization of the electrical and optical properties for each DUT. During the process development, we can determine the exact location of each chip in the testing process. Obtaining this precise position point is essential for all process steps.

This test machine includes three measurement stations with up to six different measurements installed in the system, including IVL, Farfield, Frequency and Wavelength, and Power. Each measurement is critical because the results determine if the DUT is operating properly. If a DUT fails one of the tests, we skip the following tests. This saves process time and money. It also increases the throughput and efficiency of the test facility.

We built the entire system on a massive granite structure, which uses air springs to avoid any interference caused by vibrations. We perform the necessary alignments with two different motion systems, each containing three axes. We developed the system using a vision system for fast and precise fine alignment of the probe head to the DUTs. The probe head and the carrier are highly flexible and easily interchangeable, so we can easily change to other types of DUTs.

Saving Machine Time with NI Hardware
Furthermore, we use different National Instruments multifunction data acquisition cards, as well as a dedicated Fieldbus, ProfiBUS, to monitor approximately 100 different types of analog and digital signals. We limit the user interaction to loading and unloading the DUTs, which we place on holders to save machine time. Semiskilled operators can operate the system because of its easy-to-handle software and hardware.

NI-VISA controls the external measurement equipment by using either GPIB in combination with an NI-GPIB card or the serial bus. There are approximately 10 devices installed in this way. The alignment of the DUTs to the measurement stations is one of the most important parts of the processing, because on some stations, failures of 0.5 ìm determine whether the DUT passes or fails the testing process. Therefore, we use an optical camera system with a National Instruments IMAQ PXI-1409 framegrabber in combination with a motion controller system to determine the alignment of the DUTs.

Developing a Flexible User Interface with LabVIEW
Using LabVIEW, we developed the S.E.A SpaceMaster environment to control and operate the entire system. A language-sensitive sequence editor defines the process steps. We define each step either through the SpaceMaster built-in functions or by developing new LabVIEW programs.

With LabVIEW, we can achieve high flexibility in the configuration and installation of different types of hardware. The built-in hardware abstraction makes it is simple to interchange different measurement devices of the same type without changing the test process. With this flexible and useful feature, we can avoid downtime even after a hardware failure. The end user also can easily extend the system. We also can integrate a user interface developed with LabVIEW VIs that the software environment manages. With dedicated VI and panel management, we can integrate new features and user front panels.

Using the open user interface, which uses LabVIEW and the internal add-on easy sequence programming language, the user can specify functionality and adjust the process flow as needed.

Saving Time and Lowering Costs
By using high-quality National Instruments measurement software and hardware, in combination with the SpaceMaster system, we can develop a highly-flexible machine for laser chip testing. This system shifts from manual testing to a nearly fully-automated test system with very little user interaction. Using National Instruments products, this system leads to a cost and time-saving solution with reproducible results and increased uptime.

For more infromation, contact:
Linder Höhe
51147 Köln
Germany
Phone: +49-2203–6992-0
Fax: +49-2203–6992-12
Mail: sea@sea-gmbh.com
Web: www.sea-gmbh.com