We investigated the effect of the surface roughness of the differently plated printed circuit board (PCB) on the reliability of AlGaInP-based LED packages. The electroless-plated PCB exhibited smoother surface than the electrolytic-plated one. Maximum debonding forces depended on the aspect ratios of hillocks on the plated PCB and voids. Thermo-mechanical maximum stress increased with increasing roughness height. For LED packages with the electroless-plated PCB, thermal resistance (Rth) from junction to PCB was increased by 57.43 K W-1 after operation at 85 C with 35 mA for 1000 h (reliability test), whereas for LED package with the electrolytic-plated PCB, Rth from junction to PCB increased by 4.1 K/W. The temperatures of the chip areas of the electroless-plated and electrolytic-plated samples were 91.3 and 85.3 C, respectively, after the reliability test. For the electroless-plated and electrolytic samples, the view angles along the X and Y axes were 144.43 and 142.87 , and 143.23 and 145.58 , respectively, after the reliability test. Unlike the electrolytic-plated samples, the electroless-plated samples experienced 4.8% drop in the lumen maintenance and delamination between the mold resin and PCB after operation under the 60 C/90% relative humidity condition with 35 mA for 1000 h.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials