AN INTEGRATED EXPERIMENTAL AND ANALYTICAL APPROACH TO VIBRATION SCREENING OF PRINTED CIRCUIT BOARDS

THE PROPOSED WORK WILL PROVE FEASIBLE A COMBINED FINITE ELEMENT AND MODAL TESTING APPROACH TO DEFINING AND CONTROLLING STRAIN RESPONSE OF PCBS WITHIN PRESCRIBED LIMITS WHEN UNDERGOING ENVIRONMENTAL STRESS SCREENING VIA RANDOM VIBRATION. THE APPROACH TAKES ACCOUNT OF THE STRUCTURAL DYNAMIC CHARACTERISTICS OF THE PCB, AND INTERCONNECTIONS TO IT, WHERE FLAWS MAY EXIST TO BE PRECIPITATED TO FAILURE. ANALYSIS AND TEST TOOLS WOULD BE USED TO DESIGN A SCREENER/FIXTURE TO ACHIEVE UNIFORMITY OF PCB STRAIN RESPONSE FOR ANY SLOT IN THE FIXTURE, WHILE ACCOMMODATING PRODUCTIVITY AND COST EFFECTIVENESS ISSUES WHICH ARE OF INTEREST TO MANUFACTURING PEOPLE FOR 100% SCREENING OF PCBS. THE FIXTURE DESIGN WOULD BE ADAPTABLE TO SCREENING PHILOSOPHIES INCLUDING COMBINED ENVIRONMENTS, POWER CYCLING AND FUNCTIONAL TEST DURING SCREENING. USERS COULD THEN MAKE INFORMED TRADE-OFFS (WITH FEWER UNCONTROLLED VARIABLES) BETWEEN LEVEL AND DURATION OF SCREEN TO ACHIEVE DESIRED SCREENING EFFECTIVENESS, USEFUL LIFE CONSUMED DURING SCREENING VIA FRACTURE MECHANICS TECHNOLOGY AND USEFUL LIFE REMAINING FOR SERVICE.