
“In recent years, chip LEDs are being increasingly used for numerical displays in industrial equipment and consumer devices,” said the firm. “Conventional numerical displays use a single colour to indicate numbers, but there is a growing need to change the colour to make it easier to recognise abnormalities.”
“Proprietary technologies” are credited with allowing two die to be squeezed into a package that normally only fits one, said Rohm and “after taking into consideration usage conditions during re-flow, countermeasures were adopted that prevents solder penetration within the resin package to ensure greater reliability – a resist incorporated before the gold plating process blocks the wettable gold pattern which prevents solder penetration into the resin, eliminating short-circuits.”
For dot-matrix use, as well as blocking solder wicking, the backside-only electrode design allows close mounting for high-resolution.
A red and green version has been released, with intermediate colours available by using both die, and one with a deeper red die and an amber die is under development.