Via-Hole-Type Flip-Chip Packaging to Improve the Thermal Characteristics and Reliability of Blue Light Emitting Diodes. (1st January 2019)

• Record Type: Journal Article
• Authors: Kim, Ho Young; Lim, Chang Man; Kim, Ki Seok; Oh, Jeong Tak; Jeong, Hwan-Hee; Song, June-O; Seong, Tae-Yeon; Amano, Hiroshi
• Is Part Of: ECS journal of solid state science and technology. Volume 8:Number 9(2019)
• Page Start: Q165
• Page End: Q170
• Publication Date: 2019-01-01
• Subjects: Optoelectronics -- Semiconductors -- Light emitting diode -- thermal resistance -- thermal via; Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2.0171909jss
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : We investigated the effect of via-holes in the lead-frame on the reliability of blue flip-chip light-emitting diodes (FCLEDs). For bonding, conventional Sn-Ag(3.0%)-Cu(0.5%) solder (SAC) and Ag sintered paste were adopted. Lateral LED, conventional FCLED (c-FCLED), and via-hole FCLED gave efficacies of 218.5, 221.6 and 225 lm/W at 30 mA. The lateral LED sample (bonding material: silicone), c-FCLED sample (SAC), via-hole-type sample (Ag sinter), and via-hole-type sample (SAC) exhibited total thermal resistance of 15.24, 10.19, 8.95, and 11.79 K/W, respectively. The humidity/temperature/H2 S gas reliability examinations showed that unlike the via-hole-type samples, the lumen of the c-FCLED was fallen by 15.0% after exposure for 500 h. Furthermore, the c-FCLED exhibited a 19.6% higher forward voltage than the via-hole FCLED after 1, 000 thermal-cycles. SEM results showed that unlike the via-hole type FCLED, the c-FCLED underwent cracking after thermal cycle of 1000 times.