FPC (Flexible Printed Circuit) samples bearing coplanar tracks suitable for carrying CAN signals have been fabricated using a standard low cost, high volume print and etch production technique used for automotive FPC circuits. Despite the relatively large dimensional variations between and within samples it has been demonstrated that a pair of 2 mm wide coplanar tracks having an inter-track spacing of 0.4 mm would meet the characteristic impedance and the specific line delay requirements placed on CAN physical media by the ISO 11898 standard. A track width of 7.6 mm would be required to meet the length related resistance requirement, but this would be impractical in a real FPC harness. Using a track width of 2 mm is a good compromise because it implies reducing the maximum bus length to 10.5 m, long enough for passenger vehicle automotive applications. A complication for the use of impedance controlled tracks in a real FPC harness is that proximity of the harness to car body elements such as metal parts or trim would affect the characteristic impedance. Use of adhesive foam spacers may overcome such problems. The ISO 11898 standard places no requirements on the electromagnetic compatibility (EMC) performance of the physical medium. Current work by the authors addresses this issue by comparing performance of automotive twisted pair and FPC track patterns with regard to EMC.
Foresight vehicle: physical media for automotive multiplex networks implemented of large area flexible printed circuit board
Voraussehendes Fahrzeug: Physikalische Medien für Multiplex Netzwerke auf großen flexiblen gedruckten Schaltungen
2002
5 Seiten, 5 Bilder, 1 Tabelle, 8 Quellen
Conference paper
English
Automotive engineering | 2002
|British Library Conference Proceedings | 2002
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