Heat Dissipation Properties of Thin‐Film Encapsulation by Insertion of a Metal Thin Film for Organic Light‐Emitting Diodes

Thin‐film encapsulation (TFE) technology composed of alternating inorganic/organic materials is a popular encapsulation technology for organic light‐emitting diodes (OLEDs), showing excellent heat‐transfer properties combined with a thick heat sink. TFE by inserting a metal thin film is proposed to improve the heat‐transfer property of an OLED without a separate thick heat sink. According to the presence of metal and its thickness and position, the heat dissipation effect of TFE is compared and optimized via finite element simulations. An obvious temperature‐reduction effect is observed by placing a metal thin film after each inorganic/organic unit compared with that found by placing a metal film after an inorganic/organic unit. Here, the TFE technology composed of alternating inorganic/organic/metal materials is defined as MET‐TFE. At a power density of 900 KW m −2 , the highest internal temperatures of the devices were 70.14 °C (with glass encapsulation), 72.37 °C (with TFE) and 65.63 °C (with MET‐TFE). Furthermore, the simulated thermal analysis results show that the reduction rate of device temperature for a device with MET‐TFE is comparatively faster than those of devices with TFE and glass encapsulation when increasing the convective heat‐transfer coefficient. These results suggest that the MET‐TFE structure can effectively improve heat dissipation properties.