Technical Library | 2016-11-30 15:53:15.0
The use of microvias in Printed Circuit Boards (PCBs) for military hardware is increasing as technology drives us toward smaller pitches and denser circuitry. Along with the changes in technology, the industry has changed and captive manufacturing lines are few and far between. As PCBs get more complicated, the testing we perform to verify the material was manufactured to our requirements before they are used in an assembly needs to be reviewed to ensure that it is sufficient for the technology and meets industry needs to better screen for long-term reliability. The Interconnect Stress Testing (IST) protocol currently used to identify manufacturing issues in plated through holes, blind, or buried vias are not necessarily sufficient to identify problems with microvias. There is a need to review the current IST protocol to determine if it is adequate for finding bad microvias or if there is a more reliable test that will screen out manufacturing inconsistencies. The objective of this research is to analyze a large population of PCB IST coupons to determine if there is a more effective IST test to find less reliable microvias in electrically passing PCB product and to screen for manufacturing deficiencies. The proposed IST test procedure will be supported with visual inspection of corresponding microvia cross sections and Printed Wiring Assembly (PWA) acceptance test results. The proposed screening will be shown to only slightly affect PCB yield while showing a large benefit to screening before PCBs are used in an assembly.
Technical Library | 2012-12-27 14:35:29.0
Printed Electronics is generally defined as the patterning of electronic materials, in solution form, onto flexible substrates, omitting any use of the photolithography, etching, and plating steps commonly found within the Printed Circuit Board (PCB) industry. The origins of printed electronics go back to the 1960s, and close variants of several original applications and market segments remain active today. Through the 1980s and 1990s Printed Electronic applications based on Membrane Touch Switch and Electroluminescent lighting technologies became common, and the screen printed electronic materials used then have formed the building blocks for many of the current and emerging technologies and applications... First published in the 2012 IPC APEX EXPO technical conference proceedings.
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