The large-area electronic display industry has found it absolutely essential to be able to perform in-line testing (and subsequent repair) of products for economic production. This is a consequence of the very large areas over which display manufacture takes place, and the statistical likelihood of a significant defect being present per unit area. The high value of the display backplane means that testing and repair is economically essential. A similar approach will be necessary in the next generation of low cost, Large-Area Electronics.
Although the use of low cost materials and processes in the manufacture of Large-Area Electronics means that the cost of an individual sub-system for integration into labels, novelty products, toys and games and similar applications is orders of magnitude lower than the display, there is still an economic driver for testing, assuming that the cost of the test can be made to be sufficiently low. However, whereas the testing of a display can be achieved economically using established techniques that employ probe cards and multiple communication channels, this will not be true for printed logic where production speeds could be in excess of 1 million circuits per hour and so a new approach is required to be able to perform economical testing at such high rates.
Platform for High Speed Testing of Large-Area Electronic Systems (PHISTLES) will specifically address the need for high speed testing of large-area electronics produced by reel-to-reel (r2r) manufacturing by employing a basic approach of developing a library of ‘Simultaneous Multiple Device Tests’ (SMUDTs). The key feature of the SMUDTs is that a small number of connections can be used to simultaneously test a large number of devices in parallel, whether these be analogue or digital. The technique is suited to r2r manufacture where separation of devices will be required at some point prior to shipping of a finished system, which allows elements only required for the test to be removed. We are already working on a high speed test for a specific manufacturing situation in collaboration with industry partners through the TSB AUTOFLEX project.
The aims of the PHISTLES project are:
- to develop a model for cost-effective testing of large-area electronics during r2r manufacture;
- to develop a library of techniques that can offer a step change in the cost and time for testing large-area electronics; and
- to show how these could be integrated into a generic measurement platform which itself could be included in a r2r production line.
PHISTLES: Measurement Systems
Systems for contactless testing of antennas for energy harvesting (Fig.1) using a discrete signal generator and picoscope analyser and (Fig.2) using a network analyser.