Semiconductor device and display device

A display device comprising:

• a transistor comprising a gate, a source and a drain;
• and
• a power supply wiring for supplying a power supply voltage,
• wherein the power supply wiring is formed in a grid-like arrangement,
• wherein the power supply wiring comprises:
• a first conductive thin film formed in a comb-like arrangement comprising a first tip and a second tip;
• a second conductive thin film formed in the same layer as the first conductive thin film;
• and
• a third conductive thin film and a fourth conductive thin film which comprise the same material as the gate,
• wherein the third conductive thin film is electrically connected to the first tip and the second conductive thin film,
• wherein the fourth conductive thin film is electrically connected to the second tip and the second conductive thin film, and
• wherein a conductive path is defined between the first conductive thin film and the second conductive thin film through the third conductive thin film and the fourth conductive thin film.

A display device comprising:

• a display portion;
• and
• a functional circuit, the functional circuit comprising:
• a transistor comprising a gate, a source and a drain;
• a first layer comprising a power supply wiring for supplying a power supply voltage;
• and
• a second layer comprising a wiring, which comprises the same material as the gate,
• wherein the power supply wiring is formed in a comb-like arrangement,
• wherein the wiring is electrically connected to tips of the power supply wiring, and
• wherein a conductive path is defined between the power supply wiring and the wiring.