摘要 |
A printhead for a light emitting diode printer has a transparent substrate with a row of LED dice mounted on the substrate with their light emitting Junctions adjacent to the substrate so as to emit light through the substrate. Each die has a row of LEDs along its length and a row of connection pads at known locations for making electrical connection to the LED anodes. Metal lines are deposited on the transparent substrate at known locations. Solder bumps between the connection pads and metal lines precisely position the dice by reason of surface tension. The dice are positioned in parallel rows with alternate dice staggered from each other for electrical isolation and to avoid mechanical interference at the ends of adjacent dice. In the event placement by way of the solder bumps is insufficiently precise, an opaque layer may be deposited on the substrate with a row of windows adjacent a row of LEDs. The windows are smaller than the LEDs so as to mask edge portions and alleviate alignment requirements. |