Large Size In-Line Platform for LED drivers test

The test of four different products was required. Two drivers (4ft and 5ft driver) manufactured in panels of 24 units and two main drivers (4ft and 5ft main driver) manufactured in panels of 4 units. For the 4ft/5ft driver the requirements were 4000 units/h and for the main 120 units/h.

Due to the high volumes expected, a test solution with automation was needed. The platform chosen might be able to handle big PCBs, since the main drivers used for T8/T10 fluorescent lamps, are typically long and narrow. A 6TL-35 FastATE handler was chosen, because it met the two conditions: large area PCBs accepted and automated test solution out-of-the-box. Moreover, the 6TL-35 has a bypass conveyor which allows to connect up to 4 6TL-35 in serial, increasing the testing speed, in the case the customer expands the production line.

The 6TL35 FastATE handler can be easily integrated into the production line at customer’s site using a SMEMA interface included, meaning that all the automation part of the project is turned into an easy job for the test engineer, which can focus on solving the functional test of the products.

Two test procedures were defined, depending on the product tested. The test for the 5ft/4ft driver: 4-wire measurement of the filament, and the test for the 4ft/5ft main driver: power measurement at the input and output with the driver connected to a load emulating the real environment. The 6TL-35 platform was able to detect automatically the product and select the suitable test.

Third party instruments were used to cover the FCT needs: a wattmeter for power measurement, an electronic load to simulate the LEDs and a dedicated high voltage power supply to emulate the behavior of the typical ballast for fluorescent lamps. All these instruments were integrated into the 6TL35 platform thanks to the available 19” build-in space. It is important to remark that thanks to FastATE technology, the integration job is simplified: As an example, thanks to the 6TL MMI and the 6TL Power distribution unit, the safety function to control the Emergency Power Off for all the high voltage instrumentation used, was solved without any additional job. All this instruments were controlled through USB or RS232. LabVIEW driver was developed for the high voltage power supply while for all the other instruments, drivers were already available from each supplier and we only adapted and included them into the test sequence.

Two fixtures were designed and wired as well, to perform the FCT of LED drivers. Since the fixture kits for the 6TL-35 are quite large, we could implement the test of two different products in the same fixture kit. 6TL platforms are always equipped with Virginia Panel mass-interconnect solution which was key to develop a good high voltage connection to the DUT through the VPC high power contacts. The YAV90059, included also in the Virginia Panel, was used to multiplex each driver within the panel to perform the test .

The test sequence was implemented using a complete National Instruments software suite. Test Stand allows a quickly and powerful test sequence edition, and implementation of all the steps needed like those to control the instrumentation, upload reports in specific format, control auxiliary indicators of platform, etc. Using this tool, the connection to factory server to upload test reports was also implemented.