Semiconductor device

A method of mounting a sensor in a semiconductor device, the semiconductor device comprising at least one semiconductor chip and a structure, the sensor comprising an optical fibre, wherein the sensor is configured to sense a temperature of the at least one semiconductor chip, the method comprising:

• forming a groove at a surface of the structure;
• inserting the optical fibre into the groove;
• and
• thermally and electrically coupling the structure to the at least one semiconductor chip such that the surface is located within an interior of the semiconductor device, wherein the sensor is held within the groove by friction with walls of the groove, and the structure is separate from the at least one semiconductor chip.