10.1 Objectives
• Give a brief description of a light-emitting diode (LED).
• Describe the unique packaging requirements of light-emitting diodes and their similarities to semiconductor assembly and packaging.
• Briefly discuss the reliability requirements of LED packages.
10.2 Introduction
A LED (light-emitting diode) is composed of a semiconductor chip filled with impurities to create what is known as a p-n junction, as shown in Figure 10.1. Current flows easily from the p-side (otherwise known as the anode) to the n-side (also known as the cathode) but not so in the opposite direction. The first LED products emerged in the 1960s, but in recent years they have found greater use due to many technological ...