In the course of doing some modifications to a very expensive Sony 3 chip HD camcorder I have accidentally cut through 3 tracks on the edge of a mylar? flexible cable. On the good side the damage is very accessible but the bad bit is the tracks are only 0.1mm wide on a 0.2mm pitch! Ideally one would just replace the flex pcb but in practice that would involve dismantling the camera and lens to get to all the places the pcb branches out to, and in some places it actually goes into the lens mechanism itself.
I am considering abrading off the top mylar coating to expose the copper then bridging the breaks with some very narrow pitch zebra strip. My other idea is to make my own miniature insulation displacement/piercing connector using a stack of razor blade bits sandwiched with insulation layers.
The last option would be to use wire links and solder but I think this could only be done with some sort of mechanical micropositioning rig in view of the small sizes involved.
I would be interested to hear any thoughts or experiences if anyone has any.