PCB Trace Repair (Need to keep track shape?)

Question

Need to repair a trace on my PCB. The burnt trace has a hairpin turn on it. Instead of following the same hairpin shape, can I just bridge across the undamaged points at the bottom? And also, the printed "TF b=0.4mm" on the PCB, does it have any significance to it? Next to it appears 0.6mm that has the same hairpin shape, but trace looks a bit wider. I have superimposed two pics together. One has light shone through the PCB

Answer 1

Since they're labeled TF, it's safe to state they're thermal fuses.

Therefor, since inductance is likely irrelevant, you could replace them with through-hole fuses of the correct value. The current value depends on copper layer thickness, but for 1 oz. Cu, 0.4 mm would be about 1.5 A and 0.6 mm ~2.5 A... but it would be better to find out what the actual current ratings are.

N.B. Since that 0.4 mm trace is thoroughly fried, first fix the issue that burned it out. The fuse has a purpose, and it likely prevented further damage or even a fire, so don't just bypass it.

Answer 2

Keep the track shape, the design probably intended either forming an inductor from the trace or a thermal separation or fuse. Keep the wire's cross sectional area to be a similar size of the trace. If you do make a repair, make sure the root cause of the burned trace is identified, otherwise a wire repair may end up burning out also.