PCB | March 03, 2008
Teknoflex compares component<br>count with space constraints
“Time is money” seems to have been turned to “mass is money” by many industry sectors.
However, if you use more space you will invariably use more material and incur higher costs during the production process. Performance issues such as premature mechanical failure, electrical interference within the unit, adverse thermal effects and possible degradation of signal performance will make production even riskier. PCB designers therefore try to circuit size and increase component packaging densities. Designers and manufacturers work to achieve higher layer count, micro-via interconnections, finer tracks and spaces. Equally, component suppliers must produce ever smaller footprint devices. Low mass, high density interconnection between Printed Circuit Boards (PCB’s) remains a challenge in today’s production process. The following options are examples of currently available technology: Flex Rigid Multilayer (FRML), Flex Cable/Ribbon Cable, Flex Jumper/Flat Flex Circuit (FFC), Stacked Connectors, Connectors & Wiring, Wiring Harnesses, Standard Surface Mount Interconnects (SMI‘s). Each option has its relative performance merits and cost equation as manufacturers have to balance cost against the essential requirements of performance, reliability and physical space constraints. The use of connectors, either “stacked”, or used in conjunction with standard wiring, could have cost, size and weight disadvantages. The higher level of soldered and/ or mechanical interconnection points can adversely impact on performance and reliability too. The use of wiring harnesses in isolation to achieve board to board interconnection is low in material cost, but high in labour assembly cost. Standard Surface Mount Interconnects offer an attractive low cost, low profile, low weight solution. This can also be used for higher volume applications. The standard range of SMI‘s designed by Teknoflex in the mid 1990‘s is a 0.93mm (0.0366”) pitch PCB to PCB interconnect and is offered with 4 to 22 and 33 ways. Teknoflex have developed a new High Density SMI to enhance the product range and provide a level of interconnection density. This latest development is a 0.5mm (0.0197”) pitch jumper. This will reduce the foot print even further, thus giving the designer the opportunity to increase packaging and interconnection density. This image has nothing to do this with this article.