The Experts below are selected from a list of 54054 Experts worldwide ranked by ideXlab platform

Tae Yeon Seong - One of the best experts on this subject based on the ideXlab platform.

  • via hole type flip chip packaging to improve the thermal characteristics and reliability of blue light emitting diodes
    ECS Journal of Solid State Science and Technology, 2019
    Co-Authors: Jeong Tak Oh, Tae Yeon Seong, Hwanhee Jeong, June O Song, Hiroshi Amano
    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/H2S 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.

  • improvement of the light output power of gan based vertical light emitting diodes by a current blocking layer
    Electrochemical and Solid State Letters, 2010
    Co-Authors: Hwanhee Jeong, Sangyoul Lee, Young Kyu Jeong, Kwang Ki Choi, June O Song, Yong Hyun Lee, Tae Yeon Seong
    Abstract:

    The light output characteristics of GaN-based vertical light emitting diodes (1 ×1 mm) fabricated by the multifunctional Bonding Material system have been investigated as a function of the linewidth of a SiO 2 current blocking layer (CBL). As the CBL width increases from 0 to 20 μm, the forward voltage increases from 2.82 to 2.88 V at 350 mA, whereas the reverse leakage current decreases from 4.90 × 10 -7 to 3.05 × 10 -7 A at -10 V. The output power increases with increasing CBL linewidth. Furthermore, the output power of all the samples continuously increases without saturation across the current range of 0-1000 mA.

  • Wafer-level fabrication of GaN-based vertical light-emitting diodes using a multi-functional Bonding Material system
    Semiconductor Science and Technology, 2009
    Co-Authors: Sangyoul Lee, Hwanhee Jeong, Kwang Ki Choi, June O Song, Hee Seok Choi, Tae Yeon Seong
    Abstract:

    We first report on the fabrication of 2 inch wafer-level GaN-based vertical light-emitting diodes (LEDs) by using a multi-functional Bonding Material system, which is composed of a thick Cu diffusion barrier and a Bonding layer. The Bonding Material system superbly absorbs laser-induced stress and also effectively serves as a barrier to the indiffusion of Sn to the active region. Fully packaged vertical LEDs fabricated with indium tin oxide (ITO)/AgCu contact and the Bonding Material system give an operating voltage of 3.35 V at 350 mA. After over 1800 h, the operating voltages remain stable, and the reverse currents are in the range 3–8 × 10−7 A at −5 V.

Goran Stemme - One of the best experts on this subject based on the ideXlab platform.

  • new concept for cmos compatible fabrication of uncooled infrared focal plane arrays using wafer scale device transfer Bonding
    Proceedings of SPIE, 2001
    Co-Authors: Frank Niklaus, Edvard Kaelvesten, Goran Stemme
    Abstract:

    In this paper we present a new membrane transfer Bonding technology for fabrication of uncooled infrared focal plane arrays (IRFPAs). The technology consists only of low temperature processes, thus, it is compatible with standard integrated circuits (ICs). In the future this technology may allow infrared detectors with high temperature annealed, high performance thermistor Materials to be integrated in CMOS based uncooled IRFPAs. The infrared detectors and the ICs are processed and optimized on different wafers. The wafer with the detectors (sacrificial detector-wafer) is bonded to the IC wafer (target wafer) using low temperature adhesive Bonding. The detector-wafer is sacrificially removed by etching or by a combination of grinding and etching, while the detectors remain on the target wafer. The detectors are mechanically and electrically contacted to the target wafer. Finally, the adhesive Bonding Material is sacrificially removed. One of the unique advantages of this technology is the ability to integrate small, high temperature annealed detectors and ICs. We have applied membrane transfer Bonding to the fabrication of arrays of infrared bolometers with polycrystalline silicon thermistors. In principle, membrane transfer Bonding can be applied to the fabrication of any type of free-standing transducer including bolometers, ferroelectric detectors and movable micro-mirrors.

  • low temperature full wafer adhesive Bonding of structured wafers
    Sensors and Actuators A-physical, 2001
    Co-Authors: Frank Niklaus, Helene Andersson, Peter Enoksson, Goran Stemme
    Abstract:

    In this paper, we present a technology for void free low temperature full wafer adhesive Bonding of structured wafers. Benzocyclobutene (BCB) is used as the intermediate Bonding Material. BCB bonds well with various Materials and does not release significant amounts of byproducts during the curing process. Thus void-free bond interfaces can be achieved. Cured BCB coatings have an excellent resistance to a variety of acids, alkalines and solvents and a high transparency for light across the visible spectrum, which makes it a good Material for fluidic, optical and packaging applications. We demonstrate the fabrication of fluidic structures and the embedding of protruding surface structures. An important finding is that the pre-cured BCB coatings are extremely deformable and have a liquid-like behaviour during Bonding.

  • void free full wafer adhesive Bonding
    International Conference on Micro Electro Mechanical Systems, 2000
    Co-Authors: Frank Niklaus, Edvard Kälvesten, Peter Enoksson, Goran Stemme
    Abstract:

    In this paper we present guidelines for void free adhesive Bonding of 10 cm diameter wafers. We have systematically investigated the influence of different Bonding parameters on void formation in the bond. The layer thicknesses of the tested polymer coatings are between 1 /spl mu/m and 12 /spl mu/m. The polymer Material, the Bonding pressure and the pre-curing time and temperature for the polymer has shown significant influence on void formation in the bond. High Bonding pressure and pre-curing times/temperatures that are specific to the polymer Material counteract void formation. Process parameters for achieving void-free bonds using benzocyclobutene (BCB) and photoresist coatings as adhesive Materials are given. Excellent Bonding results have been achieved with BCB as Bonding Material.

  • void free full wafer adhesive Bonding
    International Conference on Micro Electro Mechanical Systems, 2000
    Co-Authors: Frank Niklaus, Edvard Kälvesten, Peter Enoksson, Goran Stemme
    Abstract:

    In this paper we present guidelines for void free adhesive Bonding of 10 cm diameter wafers. We have systematically investigated the influence of different Bonding parameters on void formation in the bond. The layer thicknesses of the tested polymer coatings are between 1 /spl mu/m and 12 /spl mu/m. The polymer Material, the Bonding pressure and the pre-curing time and temperature for the polymer has shown significant influence on void formation in the bond. High Bonding pressure and pre-curing times/temperatures that are specific to the polymer Material counteract void formation. Process parameters for achieving void-free bonds using benzocyclobutene (BCB) and photoresist coatings as adhesive Materials are given. Excellent Bonding results have been achieved with BCB as Bonding Material.

Hwanhee Jeong - One of the best experts on this subject based on the ideXlab platform.

  • via hole type flip chip packaging to improve the thermal characteristics and reliability of blue light emitting diodes
    ECS Journal of Solid State Science and Technology, 2019
    Co-Authors: Jeong Tak Oh, Tae Yeon Seong, Hwanhee Jeong, June O Song, Hiroshi Amano
    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/H2S 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.

  • improvement of the light output power of gan based vertical light emitting diodes by a current blocking layer
    Electrochemical and Solid State Letters, 2010
    Co-Authors: Hwanhee Jeong, Sangyoul Lee, Young Kyu Jeong, Kwang Ki Choi, June O Song, Yong Hyun Lee, Tae Yeon Seong
    Abstract:

    The light output characteristics of GaN-based vertical light emitting diodes (1 ×1 mm) fabricated by the multifunctional Bonding Material system have been investigated as a function of the linewidth of a SiO 2 current blocking layer (CBL). As the CBL width increases from 0 to 20 μm, the forward voltage increases from 2.82 to 2.88 V at 350 mA, whereas the reverse leakage current decreases from 4.90 × 10 -7 to 3.05 × 10 -7 A at -10 V. The output power increases with increasing CBL linewidth. Furthermore, the output power of all the samples continuously increases without saturation across the current range of 0-1000 mA.

  • Wafer-level fabrication of GaN-based vertical light-emitting diodes using a multi-functional Bonding Material system
    Semiconductor Science and Technology, 2009
    Co-Authors: Sangyoul Lee, Hwanhee Jeong, Kwang Ki Choi, June O Song, Hee Seok Choi, Tae Yeon Seong
    Abstract:

    We first report on the fabrication of 2 inch wafer-level GaN-based vertical light-emitting diodes (LEDs) by using a multi-functional Bonding Material system, which is composed of a thick Cu diffusion barrier and a Bonding layer. The Bonding Material system superbly absorbs laser-induced stress and also effectively serves as a barrier to the indiffusion of Sn to the active region. Fully packaged vertical LEDs fabricated with indium tin oxide (ITO)/AgCu contact and the Bonding Material system give an operating voltage of 3.35 V at 350 mA. After over 1800 h, the operating voltages remain stable, and the reverse currents are in the range 3–8 × 10−7 A at −5 V.

Sangyoul Lee - One of the best experts on this subject based on the ideXlab platform.

  • improvement of the light output power of gan based vertical light emitting diodes by a current blocking layer
    Electrochemical and Solid State Letters, 2010
    Co-Authors: Hwanhee Jeong, Sangyoul Lee, Young Kyu Jeong, Kwang Ki Choi, June O Song, Yong Hyun Lee, Tae Yeon Seong
    Abstract:

    The light output characteristics of GaN-based vertical light emitting diodes (1 ×1 mm) fabricated by the multifunctional Bonding Material system have been investigated as a function of the linewidth of a SiO 2 current blocking layer (CBL). As the CBL width increases from 0 to 20 μm, the forward voltage increases from 2.82 to 2.88 V at 350 mA, whereas the reverse leakage current decreases from 4.90 × 10 -7 to 3.05 × 10 -7 A at -10 V. The output power increases with increasing CBL linewidth. Furthermore, the output power of all the samples continuously increases without saturation across the current range of 0-1000 mA.

  • Wafer-level fabrication of GaN-based vertical light-emitting diodes using a multi-functional Bonding Material system
    Semiconductor Science and Technology, 2009
    Co-Authors: Sangyoul Lee, Hwanhee Jeong, Kwang Ki Choi, June O Song, Hee Seok Choi, Tae Yeon Seong
    Abstract:

    We first report on the fabrication of 2 inch wafer-level GaN-based vertical light-emitting diodes (LEDs) by using a multi-functional Bonding Material system, which is composed of a thick Cu diffusion barrier and a Bonding layer. The Bonding Material system superbly absorbs laser-induced stress and also effectively serves as a barrier to the indiffusion of Sn to the active region. Fully packaged vertical LEDs fabricated with indium tin oxide (ITO)/AgCu contact and the Bonding Material system give an operating voltage of 3.35 V at 350 mA. After over 1800 h, the operating voltages remain stable, and the reverse currents are in the range 3–8 × 10−7 A at −5 V.

June O Song - One of the best experts on this subject based on the ideXlab platform.

  • via hole type flip chip packaging to improve the thermal characteristics and reliability of blue light emitting diodes
    ECS Journal of Solid State Science and Technology, 2019
    Co-Authors: Jeong Tak Oh, Tae Yeon Seong, Hwanhee Jeong, June O Song, Hiroshi Amano
    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/H2S 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.

  • improvement of the light output power of gan based vertical light emitting diodes by a current blocking layer
    Electrochemical and Solid State Letters, 2010
    Co-Authors: Hwanhee Jeong, Sangyoul Lee, Young Kyu Jeong, Kwang Ki Choi, June O Song, Yong Hyun Lee, Tae Yeon Seong
    Abstract:

    The light output characteristics of GaN-based vertical light emitting diodes (1 ×1 mm) fabricated by the multifunctional Bonding Material system have been investigated as a function of the linewidth of a SiO 2 current blocking layer (CBL). As the CBL width increases from 0 to 20 μm, the forward voltage increases from 2.82 to 2.88 V at 350 mA, whereas the reverse leakage current decreases from 4.90 × 10 -7 to 3.05 × 10 -7 A at -10 V. The output power increases with increasing CBL linewidth. Furthermore, the output power of all the samples continuously increases without saturation across the current range of 0-1000 mA.

  • Wafer-level fabrication of GaN-based vertical light-emitting diodes using a multi-functional Bonding Material system
    Semiconductor Science and Technology, 2009
    Co-Authors: Sangyoul Lee, Hwanhee Jeong, Kwang Ki Choi, June O Song, Hee Seok Choi, Tae Yeon Seong
    Abstract:

    We first report on the fabrication of 2 inch wafer-level GaN-based vertical light-emitting diodes (LEDs) by using a multi-functional Bonding Material system, which is composed of a thick Cu diffusion barrier and a Bonding layer. The Bonding Material system superbly absorbs laser-induced stress and also effectively serves as a barrier to the indiffusion of Sn to the active region. Fully packaged vertical LEDs fabricated with indium tin oxide (ITO)/AgCu contact and the Bonding Material system give an operating voltage of 3.35 V at 350 mA. After over 1800 h, the operating voltages remain stable, and the reverse currents are in the range 3–8 × 10−7 A at −5 V.