A technical note about Thin Film fuses from Vishay. Link here (PDF)
Thin film technology is an established technology for high-grade passive components, which has been proved and refined over decades. Its advantages in terms of accuracy, repeatability and stability are appreciated in mass production for billions of thin film resistors every year. Chip fuses produced in thin film technology now deliver similarly predictable properties in terms of the stability and repeatability of the fusing characteristic. With this proven technology embodied in next-generation safety devices for overcurrent protection, power electronics designers can achieve higher levels of safety and performance in new product designs.
from Dangerous Prototypes http://ift.tt/2qoRmkS