Hello, all.
I'm having to critique a board that is a very large flex circuit. It's kind
of funky in that it isn't a conventional board, but rather an array of 22
resistive sensors spread over a (roughly) 18x24 inch area. The board looks
like like six 1/2 inch fingers extending, vertically, 24 inches from a 2
inch, horizontal, section. The connector comes off the 2 inch part and each
sensor is mounted on the 1/2 inch stripes (either 3 or 4 sensors per strip.)
The current version of the board appears to have fairly wide traces
(eye-balling, they appear to be 10-15 mils), This sensor array will be in a
constant state of movement (it will sit on a dense foam pad which will be in
a regular state of "flex" as heavy items are laid on the pad), there fore,
the flex circuit will be flexed, a lot, over time.
Here are my questions:
1) How narrow can I make the traces on flex circuit?
Currently, the 2 inch horizontal part is full of 48 traces (2 per sensor)
and I'd like to re-spec that section to be narrower.
2) How much flex board material is needed to support the traces?
The current design has about 1/4 (maybe 3/16) inch of flex material on the
board edge. That is, the routing outline is 1/4 inch inside the board edge.
Can this be reduced to 1/8 or 1/16 inch, or less? If I can go to 8 mil
traces (with 8 mil space) and use 1/16 inch between the board edge and the
routing outline, then the portion of the board that has only 2 traces would
be .149 inches wide ((.0625 X 2) + (.008 x 3)).
Thanks,
David R
-----------------------------------
David M. Ransier
Senior Consultant
Intercept Technology Inc.
[log in to unmask]
503-692-0111 www.intercept.com
503-691-9535 - Fax
404-352-0111 - ITI Headquarters
################################################################
DesignerCouncil E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe: SUBSCRIBE DesignerCouncil <your full name>
To unsubscribe: SIGNOFF DesignerCouncil
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################
################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe: SUBSCRIBE TechNet <your full name>
To unsubscribe: SIGNOFF TechNet
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################
|
