Research on the reliability of Micro LED high-density solder joints under thermal cycling conditions

Abstract

For the purpose of studying the effect of high-density, small-size solder joints on the thermal fatigue life of display devices, a 3D model of the corresponding device structure is established, using finite element analysis methods, and using Anand constitutive equations and Coffin-Manson life prediction models. The equivalent stress and strain change law of an indium solder joint with a diameter of 10 μm under thermal cycling loading conditions is explored, and the key position of the solder joint damage is inferred based on the simulated strain cloud diagram. In addition, the influence of different bump height, bump contact area and Under-Bump Metallization (UBM) thickness on the thermal fatigue life of solder joints is studied separately. The final simulation results show that the location where the solder joint may be damaged first is at the point on the outer side where the solder joint is connected to the UBM on the edge away from the center point. The height of the bump and the contact area of the bump have a significant effect on its thermal fatigue life. In the actual experiment, we should focus on the impact of this aspect.

Rectangular Amplitude Mask-Based Auto-Focus Method with a Large Range and High Precision for a Micro-LED Wafer Defects Detection System

“…The Micro-LED (light-emitting diode) display is a new generation of display devices that can integrate drivers, light emitting, and signal transmission, and it can realize an ultralarge-scale integrated light-emitting unit. With some excellent characteristics, such as small chip size, high integration, self-emitting, and low energy consumption [1,2], the Micro-LED display has great advantages in brightness, resolution, contrast, color gamut, and energy consumption compared with LCD (liquid crystal display) and OLED (organic light-emitting diode) in display [3][4][5]. However, the mass production of Micro-LED displays still faces some problems such as miniature chips and low yield.…”

Applicability Evaluation of Nano-Al2O3 Modified Sn-Ag-Cu Solder in High-Density Electronic Packaging Subjected to Thermal Cycling

“…As is known, interconnections not only act as electrical connections, but also undertake a role of a mechanical support [9,10]. Considering the communication demand of higher data transmission rate and lower delay, high-density interconnections with decreased size become necessary.…”