The challenge:

To build a reliable, intuitive and fast test station to guarantee the quality in the production of REAR LAMPS. The system needs to be portable and as compact as possible, and has to measure the current and voltage consumption of the DUT as well as LED color.

The solution:

We have combinated 6TL products, which are helping usin the integration time, with NI software for image aquisition and analysis.

Article:

In the automotive market every second is important, and as part of the production line, the test equipment can not be the bottle neck. REAR LAMPS are electronic PCBs with LEDs. The challenge will be to obtain in a fast and precise manner, all the features of these LEDs.

Description of the DUT

The REAR LAMPS are PCBs with LEDs, connectors to power up the DUT and other passive electronics. Depending on the design of the DUT, it will be necessary the use of loads to test it. A variation in the power suppied to the DUT, will mean a variation in the current consumption and therefore the intensity of the LEDs.

Test platform descirption

The ATE is based on a 6TL-22. This platoform features an IPC with Windows XP Professional, protected thanks to an UPS that will control its power supply. The IPC and all other instrumenation is stacked in standard 19 inch rack available in the platform . A power management module (again 19 inch stack&rack module) is also available in the platform, allowing the operator to turn it on and off and to navigate through the platoform software menus (Operator Interface SW).
To test every DUT, the operator will have to place it on on the cameras-fixture. A template over the cameras-fixture will adapt that particular DUT to the “Common plataform + cameras-fixture”. The template is made of antistatic material and has the exact shape of the DUT and a connector to plug the DUT in a fast and easy way. Inside the fixture we can find 6 cameras with their optics, constituting a matrix that will cover an area of 500x250mm. The platfrom features a G12 receiver from Virginia Panel with some 6TL YAV switching modules that will connect the DUT to the instruments. YAV modules make engineers save wiring, debugging and maintenance time. All 6TL modules are controlled through CAN bus thanks to a NI PCI-CAN integrated in the IPC.

Software

To create the test executive software, we have used as a base the PHI6 SW package from 6TL. This package is based on LabView and Teststand and has all the drivers and palettes to manage all 6TL modules. The Operator Interface is friendly to the operator; it receives and displays all the needed information related to the processes that are running real time, as well as the status of the platofrm. We can control the platofrm throuth the Operator Interface either through the navigator integrated in the power management module or through the PC keyboard. The test sequence is semi-automatic: the operator will choose the product, and will choose wether to to start or to finish testing.

Test cycle

The 6TL-22 comes with a barcode reader that will identify the DUT. Thanks to this information, PHI6 will call the corresponding sequence showing their features in a 17 inch high resolution TFT. If the DUT does not fit the template placed on the fixture, the Operator Interface will display a Fixture Warning. Once the barcode is read and the platoform has the matching template, PHI6 will configure all the instrument parameters and TestStand variables to test the DUT. Finished this operation, PHI6 will inform the operator that the platform is ready to test. The operator can now place a DUT on the fixture with the LEDs facing the cameras and connect it. Once the light is detected, the cycle will start. First step will be to measure the current consumption through the PCI 6221 DAQ, that will give us high resolution as well as more than one measurement channel in parallel. Second step will be LEDs testing: color measurement and relative intensity measurement. The cameras are controlled through Firewire thanks to two PCI-8252 boards. Images acquired are processed and evaluated with Vision Builder. Once the cycle is finished, PHI6 will display through the Opetator Interface the results; a Test Report will be automatically generated and a label is printed.

Conclusion:

6TL modules together with National Instruments tools are the perfect combination for a fast and reliable ATE manufacturing. LabView and TestStand SW platforms are proven time saving factors when talking about test environments. In addition, 6TL modules are allowing test engineers solve mechanics and HW and therefore conentrating on the final customization of the system. The cycle time has been impoved with the acquisition speed of NI HW, allowing image acquisition and analysis in real time.

Autors:

Juan Marin, Test Systems Engineer