Simple and flexible test definition
Elaborate test program debugging is also often a challenge in a panel test. This is supported by the Digitaltest Computer Integrated Test Environment (CITE). Here, all test parameters are created only once and then automatically transferred to all PCBs of the panel (Fig. 4). However, what is important here is the openness and flexibility for exceptions and irregularities, for example if a more expensive test resource is to be used successively by all boards, e.g. a power supply. It can also be flexibly selected whether tests for the entire panel or for each individual board should be documented separately.
For this purpose, a bar code on the panel is scanned and assigned a unique identifier (depending on the specifications of the respective application) via the position of each board on the panel. The entire concept also works with mixed panels. In addition to the test software, the user interface of the test program in CITE can be easily adapted to individual needs. For traceability, the software also stores all test data in a database. The software can be used to significantly reduce the overhead of creating panel tests compared to a single test.
Parallelization eliminates panel test bottleneck
However, not only the planning of tests and test equipment is challenging, but the practical implementation of the tests is as well. If all boards on the panel are sequentially tested in a conventional manner, this can slow down the entire production line. When using a test system with several test heads (Lambda edition), two or more boards can be tested simultaneously in parallel. This reduces the cycle time and the throughput on the tester increases accordingly. One PC can control several test heads, which are connected to the panel via an adjusted adaptation (Fig. 5).
The Lambda edition software provides all the functions needed to control such a parallel test. This includes both the communication with the operator or handling system as well as the control and possibly synchronization of the test processes. Maximum performance is achieved when all test steps are executed in parallel. In addition, the Lambda edition is designed to be very flexible, for example, one expensive hardware resource can only be installed once and the software coordinates or synchronizes the respective use sequentially. This can cost-effectively achieve optimum throughput. The software of the Lambda edition is divided into the actual test programs and a coordinator, which controls the parallel running tests. Thus, with one PC and two test heads, the cycle time of the test station can be halved or reduced with a four-head system to one quarter of the sequential test time.