Answer: Gold (Au) is used in mid- to high-end products as the bonding wire. Copper (Cu) is often used in mass-marketed products as the bonding wire.

Products using Gold have a higher and more consistent product quality. Heat also dissipates less, making it more energy efficient (~10%). Since it has more stable physical properties, it relatively has a longer life than Copper. Copper, however, has a higher price-performance ratio than Gold, making it the appropriate selection for mainstream DVLED products.