Testing of an electronic board on a flying probe system

This master thesis has been carried out in collaboration with SPEA, a worldwide electronic testing leader company. SPEA systems have several fields of application: automotive, MEMS and sensors, aerospace, communications and medical. As biomedical devices are essential for the patient's health, testing them becomes crucial for their proper functioning. Therefore, feasible testing procedures are necessary. Many manufacturers adopt SPEA systems to guarantee both product functionality and integrity. During this internship, I have focused on the general issue of testing an electronic board in order to develop its basic principles. SPEA testing is divided into three main phases: in circuit test (ICT), on board programming (OBP) and functional test (FCT). By going into details, I have worked on a flying probe system which is a SPEA automatic test equipment. Firstly, I have focused on an in circuit test plan which aims to test the components electrically. The most common electrical tasks are: short circuit test, open circuit test, resistance test, capacitance test and other electrical parameter tests that reveal the electronic board's total compliance to what has been designed. Then, I have been involved in on board programming, a SPEA procedure whose purpose is programming microcontrollers. About this field, I have implemented a customized OBP: in addition to loading the firmware (supplied by the customer), it has to write a unique identifier in the flash memory as a way of signing each under test microcontroller. This work has been developed adopting SPEA proprietary software and libraries that allows a test engineer to interface with system automation and resources in order to achieve three fundamental OBP steps: chip erase, write and verify. This functional OBP has been developed in a Visual Basic language. At last, I have developed an optical test which belongs to a functional tests class, designed with the purpose of testing electronic board behavior. In this case the board is equipped with optical led guides and a display. It has designed a customized morphological optical test named scratch test, so as to detect and therefore sign as failed all boards with morphological defects compared to what would have been expected. The test has been developed in collaboration with the R&D company department adopting a SPEA image processing tool named Optical Test App. A first feasibility study has been carried out; then the optical morphological test has been integrated in a test program developed in C# language. The optical test strategy is based on the idea to adopt a template as a reference to understand if there is a light leakage or a partially film dimming on the led display. Scratch test could be applied into the biomedical field, with a focus on display equipped devices as far as to recognize any possible defects. The functional test has been validated on several samples of each customer variant and this functional application has been installed into the customer plant. As a result, the customer industrial production has gone forward up to date adopting an in line SPEA four axes flying probes system with the required throughput.