Query: die bonding

title: Research on High Precision Micro assembly Technology for Automated MEMS Thermopile Chip Die Bonding Process
abstract: The focus of this paper is to develop high precision MEMS thermopile automated die bonding system. Firstly, the working principle of MEMS thermopile chip is explained and the minimum threshold value of the die bonding precision is 200 um. Based on the solid state process of MEMS thermopile chip, the influence of die bonding precision on chip temperature measurement and chip die bonding strength is analyzed. On this basis, the mechanical composition of high precision automated die bonding system is determined, so that the hardware accuracy of the system meets the requirements. By analyzing the image characteristics of silver paste and chip, different image processing algorithms are determined to improve the recognition accuracy of the image. Using the multi factor analysis of variance method, the MEMS thermopile automated die bonding system is used as the experimental platform to determine that the pressure parameters is the primary factor of the die bonding process. And through the dispensing experiment, the optimal pressure value of the die bonding system is determined. Finally, the precision of the MEMS thermopile die bonding system was verified under the optimal pressure parameters. The results show that the MEMS thermopile automated die bonding system can achieve patch with accuracy within 25um when the pressure parameter is 0.3MPA. It meets the accuracy requirements and helps to improve the reliability and yield of MEMS thermopile chip packages.

title: Microstructural and thermal characterizations of light emitting diode employing a low temperature die bonding material
abstract: Bi bilayer was deposited on a hot air solder leveling (HASL) treated metal core printed circuit board (MCPCB) using electroplating as a low temperature die bonding material for light emitting diode (LED) The eutectic feature of the Sn/Bi contact enabled the die bonding process to accomplish through a liquid/solid reaction at 185 degC with a proper compression force. A high temperature die bonding structure composed of a Bi layer sandwiched by two intermetallic compounds (IMCs) formed after thermocompression. Employment of the Sn/Bi bilayer for low temperature die bonding prevented the LEDs from thermal stress problems, and the resulting high temperature IMC/Bi/IMC die bonding structure was capable of withstanding multiple bonding reactions and high temperature/current operation environment. Durability tests including mechanical, thermal, and optical performance were systematically performed and compared with other commercially available die bonding materials (Ag paste and solder alloys)

title: Reconstruction and thermal performance analysis of die bonding filling states for high power light emitting diode devices
abstract: This paper proposed a half experimental model to reconstruct the die bonding thermal path of high power light emitting diodes (HP LEDs) In this model, the partially insufficient filling of bonding materials and their directional/random distributions "filling state" for short) have been taken into consideration. Both the silver paste structure and the Au/Sn eutectic structure were analyzed and compared. Finite element analysis (FEA) indicated that qualified die bonding with uniform filled areas would lead to much better thermal performance. Hotspots have been observed above the insufficiently filled regions. The simulated thermal resistances of the defective bonding were 5.4 times and 2.1 times higher than those of the qualified samples under conditions of Au/Sn eutectic and silver paste, respectively. Transient thermal resistance measurements further demonstrated that the devices with different filling states would result in distinct thermal resistances. Interestingly, it was noted that although the qualified silver paste bonding had a larger filled area, the measured thermal resistance remained higher than that of the defective Au/Sn eutectic bonding because of the high contact thermal resistance caused by poor wetting properties. Furthermore, defectively bonded LED devices revealed a poor maintenance of luminous flux after 500 h of aging, which was consistent with the results of thermal performance analysis on the reconstructed die bonding models.

title: Analysis of Crack Formation in Germanium Substrate at AlInGaP Die Bonding Process
abstract: Cracked die is a serious failure mode in Light Emitting Diode (LED) industry affecting the LED quality and long term reliability performance. In this paper, an investigation has been carried out to find out a relation between die bonding force and the occurrence of die crack at Germanium (Ge) substrate due to die attach (DA) ejector pin indentation. Based on the analysis, the results show that cracks start to occur at 60 gram force (gF) bond force and above. The crack length at the die substrate increases with respect to the bond force. These indented dies were further analyzed by using Scanning Electron Microscope (SEM) The results show plastic deformation, slip traces and material pile up at the vicinity of ejector pin crater. Some samples were sectioned using Focus Ion Beam (FIB) and it was found the crack depth does not exceed beyond 20.5mm and it follows the (111) plane. These findings, concludes that cracks start to appear at 60gF and they are confined to surface level even indented at extreme load (140gF) These cracks are far away from the active region of LED.

title: Die Bonding Material and Sintering Joining Technology for Power Semiconductors Allowing Operation at High Temperatures
abstract: Power semiconductors are widely used in various fields including household appliances, industrial motors, vehicles, and energy transmission and distribution systems. With their operating temperatures showing a rising tendency due to the increasing demand for higher efficiency as well as the application of silicon carbide (SiC) semiconductors, the junction temperature of such devices is expected to exceed 200degC. It is therefore necessary to develop a heat resistant die bonding material to bond chips to substrates. To address this issue, Toshiba has focused on a silver (Ag) nanoparticle material as a die bonding material that possesses superior heat radiation characteristics and can withstand high temperatures exceeding 200degC. In order to realize a die bonding material with higher reliability than existing materials, we have also developed a metal salt solution nanoprecipitation (MS2NP) method as a countermeasure against the degradation of die attachments consisting of sintered Ag nanoparticles.

title: Thermal Management of The Die Bonding Architecture in 3D Ics
abstract: This paper presents the thermal impact of different bonding architectures in the 3D stacked chip.ANSYS(r) Workbench(tm) 14.0 was used to model the architecture and meshed analysis was conducted. Bonding architectures that evaluated were face to face, face to back and back to back while all the parameters and boundary conditions were held constant. A futher discussion is the effect of changing the corresponding parameters or the boundary conditions in the thermal management performance. In that light, a list of cases consisting of increasing the heat transfer co efficient on top of the package, improving the thermal conductivity of the bonding layer, the TIM and the package as well as the using of microchannels were evaluated. Simulation results shows that the different bonding architecture has little impact on the maximum temperature of 3D stacked chip that without m icrochannels. When the microchannels are introduced, the bonding architecture has the important impact. Moreover, from the point of the thermal management performance, it found that changing onl y one single parameter can decrease little the maximum temperature. The case of intruducing microchannels offered significant improvement in thermal performance.

title: Process Capability Optimization of a LED Die Bonding Using Response Surface Analysis
abstract: In LED chip packaging, die bonding is a very important process which fixes the LED chip on the lead frame to provide enough strength for the next process. This paper focuses on the process optimization of a LED die bonding, which attaches small zener diode chip on PLCC LED package frame, using response surface analysis. Design of experiment (DOE) of 5 factors, 3 levels and 5 responses are considered, and the results are investigated. As the results, optimal conditions those satisfy all response objects can be derived. Key Words LED chip package, Die bonding(or attaching) Design of experiment, Response surface analysis bon nonmuneun jisiggyeongje gisulhyeogsinsaeob(sinseongjangdongryeogjangbigyeongjaengryeogganghwasaeob)yi ilhwaneuro suhaengjungin 'LED paekiji In line jadonghwa siseutem gaebal' gwaje yeongubi jiweoneuro suhaengdoeeosseum.  2753 email: sjha1103@gmail.comjeobsuil 12nyeon 07weol 31il sujeongil (1ca 12nyeon 08weol 22il, 2ca 12nyeon 09weol 14il, 3ca 12nyeon 09weol 27il) gejaehwagjeongil 12nyeon 10weol 11il 1. seoron LED cibyi ilbanjeogin paekijing gongjeongeun weipeoe hyeongseongdoen cibyi yangbureul geomsahaneun weipeo geomsa gongjeong, weipeoreul jeoldanhayeo natgaero bunridoen cibeul rideu peureim(lead frame)e bucagsikineun dai bonding(die bonding) gongjeong, daie gubidoen jeobcog paedeuwa rideu peureimyi rideureul waieoro yeongyeolsikineun waieo bonding(wire bonding) gongjeong, daiyi naebuhoerowa geu oeyi guseong bupumeul bohohagi wihae bongjijaero oebureul gamssaneun molding(molding) gongjeong, rideuwa rideureul yeongyeolhago daemba(dam bar)reul jeoldanhaneun teurim gongjeong mic rideureul weonhaneun hyeongtaero seonghyeongsikineun poming(forming) gongjeongeul geocige doenda. geujungeseo dai bonding gongjeongeun bunhaldoen cib(die)i ihu gongjeongeseo gyeondil su issneun cungbunhan gangdoyi jeobcagryeogeul gajdorog cibeul gojeongsikigo cibeurobuteo balsaenghaneun yeoleul bangculsikigi wihae jeogjeolhan yeoljeondodo mic jeongijeondodoreul buyeohaneunde isseo maeu jungyohan gongjeongimyeo, tongsangjeogin dai bonding gongjeongsunseoreul geurim 1e natanaeeossda[1,2]

title: Semiconductor Die Bonding
abstract: Adhesive die attach materials are suspensions of metal particles in a carrier. The particles are several mm in size, usually in the form of thin flakes of silver. The carrier provides adhesion and cohesion to make a bond with the correct mechanical strength, while the metal particles provide electrical and thermal conductivity. It is noticeable that conductive resins are now often used where no electrical connection is required, just to get the benefit of enhanced thermal performance.

title: Electronic materials and components Die bonding materials
abstract: must not transmit destructive stress to the fragile chip must make intimate contact between the chip and substrate materials, with no voids, and adhere well to both has to withstand temperature extremes without degrading. should exhibit good thermal conductivity, to remove heat generated within the chip should be either a good electrical conductor or a good insulator, depending on the application.

title: A study of large area die bonding materials and their corresponding mechanical and thermal properties
abstract: We tested the ability of Au/Sn eutectic, silver paste, and solder paste to bond to a large area as well as the bonding of a high power LED die to a highly conductive submount. The samples ran through several tests including ultrasound image, shear force, and thermal resistance measurement. Finite element analysis (FEA) models were built for comparison and analysis. Au/Sn bonding shows the best thermal and mechanical properties. Silver paste shows lower contact thermal resistance compared with solder paste. Although the thickness of the silver paste bonding layer is greater than the solder paste bonding layer, the average total thermal resistance is noticeably lower than the solder paste bonded samples.