A Screen Method for the Mass-Production of the Small-Size and Side-View LED Package

Abstract

In this study, the small-size and side-view LED packages used in the backlight modules were examined by performing the electrostatic discharge (ESD) process. The high voltages used for the ESD process were 2 kV, 3 kV, and 4 kV. After ESD, the current–voltage curves were scanned from −7 V to 3 V. It was found that the significant leakage currents were in the reverse bias of 4 V~7 V and also in the forward bias of 1 V~2.5 V for ESD-damaged LED chips. However, the phenomenon of a slight increase in current was not found for the non-damaged samples. In our study case, the screening conditions could be set at a bias of −7 V or 2.3 V and the current of 0.1 µA.

The Photometric Test Distance in Luminance Measurement of Light-Emitting Diodes in Road Lighting

“…This set-up allowed measurements at distances of up to 1 m. The main component of the stand was a goniophotometer (1), which allowed for the fixing of the specially designed cooling system (2) in the form of a heat sink and tested high-power LEDs (3). Before the measurements, the LEDs were positioned using two lasers (4) and two-micrometre screws (5) placed on a measuring table (6). The goniophotometer allowed high-power LEDs to be tested in the system (C,γ).…”

“…Light-emitting diodes are among the most popular light sources. LEDs have practically replaced traditional light sources on the market because of their advantages, such as high luminous efficacy [1][2][3], long operating time [4,5], a small size [6], insensitivity to shock, high luminance [7][8][9][10], resistance to low temperatures [11] and easy control [12][13][14][15]. So, in interior lighting, LEDs have replaced fluorescent lamps [16] and in road lighting, they have replaced high-pressure sodium lamps [17,18].…”