Die-Attach Voiding Reduction in Gold Alloy Solder Preforms

2017 ◽  
Vol 2017 (HiTEN) ◽  
pp. 000099-000102
Author(s):  
Bernard Leavitt ◽  
Andy C. Mackie
Keyword(s):  
High Temperature ◽  
Eutectic Alloy ◽  
Hot Spots ◽  
Gold Alloy ◽  
High Reliability ◽  
Eutectic Alloys ◽  
Power Semiconductor ◽  
Power Semiconductor Devices ◽  
Die Attach ◽  
Alloy Solder

Abstract The need for high-temperature solders is growing as RF and power semiconductor devices continue to get smaller, with power density increasing both as a consequence of the shrink and as a result of increased power ratings. AuSn20 eutectic solder (Indalloy®182) has been the workhorse for high-temperature, high-reliability, small die-attach applications for many years; however, as junction temperatures (Tj) increase, the gold-tin eutectic is beginning to reach its limit of utility. Higher temperatures cause increased thermal fatigue, and even delamination is seen at the solder joints. The next option for RF and power semiconductor manufacturers needing these higher temperatures is either AuGe12 (Indalloy®183) or AuSi3.2 (Indalloy®184) eutectic alloy (see Table I).Table 1.Key properties of Au-based eutectic alloys. Over the years, many customers have tried AuGe12 and the feedback has been that the alloy has poor solderability, which manifests as large voids in the bond. Voids are poor conductors of heat, which create hot spots, and are the primary cause of premature failures.

Nanoindentation of Porous Die Attach Materials as a Means of Determining Mechanical Attributes

2013 ◽  
Vol 393 ◽  
pp. 57-62
Author(s):  
Vemal Raja Manikam ◽  
Kim Seah Tan ◽  
Khairunisak Abdul Razak ◽  
Kuan Yew Cheong
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Young Modulus ◽  
Inter Metallic Compound ◽  
Organic Additives ◽  
Power Semiconductor ◽  
Power Semiconductor Devices ◽  
Al Nanoparticles ◽  
Die Attach ◽  
Sintered Ag

A die attach nanopaste for high temperature use on silicon carbide (SiC) based power semiconductor devices was developed utilizing silver (Ag) and aluminium (Al) nanoparticles as well as organic additives. Total nanoparticle content was varied at 84.7, 85.5, 86.2 and 87 wt%, while the Ag to Al ratio was fixed to 80:20. The die attach nanopaste was sintered in open air at 380 °C for 30 minutes to create an Ag-Al inter-metallic compound between the SiC die and substrate. To determine the mechanical attributes of the post-sintered die attach interlayer, nanoindentation was performed on the samples. It was found that, a low Young modulus of elasticity, E, between 9.3-9.8 GPa was obtained. This was followed by a reduction in hardness as well as stiffness for the post-sintered Ag80-Al20 die attach material when compared against that of solder alloys or bulk metals. The formation of pores in the die attach material as it underwent sintering is believed to have contributed to this decrease in mechanical properties. The findings of this research enables the possibility of introducing a much cheaper die attach material for high temperature devices, which also has excellent mechanical properties to alleviate thermal mismatch issues between the semiconductor die and substrate.

A New Lead-Free Solder Joint Utilizing Superplastic Al-Zn Eutectoid Alloy for Next Generation SiC Power Semiconductor Devices

2016 ◽  
Vol 838-839 ◽  
pp. 482-487 ◽  
Author(s):  
Jin Onuki ◽  
Akane Saitou ◽  
Akio Chiba ◽  
Kunihiro Tamahashi ◽  
Yoshinobu Motohashi ◽  
...  
Keyword(s):  
High Temperature ◽  
Solder Joint ◽  
Bonding Strength ◽  
Lead Free ◽  
Lead Free Solder ◽  
Power Semiconductor ◽  
Power Semiconductor Devices ◽  
Alloy Solder ◽  
Free Solder ◽  
Eutectoid Alloy

A new high-temperature lead-free solder joint which withstands up to 300°C utilizing superplasticity in the Al-Zn eutectoid alloy has been developed to realize SiC power semiconductor devices. The new solid state joining process consists of interfacial cleaning of joints utilizing superplasticity of the Al-Zn-eutectoid alloy at 250°C followed by diffusion bonding between 350 and 390°C. The bonding strength of the new joints exhibits almost the same value at the temperature range from RT to 300°C, above which it decreases slightly with increasing temperature. It is also found that the bonding strength of the new joints is 8 times as high as those of a high-temperature Pb-5wt%Sn-1.5wt%Ag solder and the Al-Zn eutectoid alloy solder without utilizing superplasticity at 250°C. The Al-Zn eutectoid alloy solder joint has shown high reliability in the temperature cycle testing between 50°C and 300°C up to 300 cycles.

Effect of Sintering Time on Silver-Aluminium Nanopaste for High Temperature Die Attach Applications

2012 ◽  
Vol 576 ◽  
pp. 199-202
Author(s):  
Vemal Raja Manikam ◽  
Abdul Razak Khairunisak ◽  
Kuan Yew Cheong
Keyword(s):  
High Temperature ◽  
Semiconductor Devices ◽  
High Surface ◽  
Nanoscale Materials ◽  
X Ray ◽  
Power Semiconductor ◽  
Power Semiconductor Devices ◽  
Al Nanoparticles ◽  
Sintering Time ◽  
Die Attach

Nanoscale materials, primarily metallic elements have been proven as suitable solutions for interconnect technology on power semiconductor devices. Nanoscale materials possess high surface energies thus enabling them to be processed at lower temperatures for high temperature applications of more than 500°C. This literature work aims to present a novel silver-aluminium (Ag-Al) nanoalloy die attach paste solution for power semiconductor devices. Ag and Al nanoparticles were pre-mixed into an organic paste system using binders and a surfactant. Viscosity tests concluded that the Ag-Al nanopaste is suitable for mass manufacturing dispensing and screen printing with an average value of 47,800 cps. Thermogravimetric analysis was used to design the sintering profile at 380°C from 10 to 30 minutes. X-ray diffraction analysis detected the formation of Ag2Al and Ag3Al compounds in the post-sintered nanopaste. Scanning electron microscopy and Energy-dispersive X-ray spectroscopy showcased larger grains in the nanopaste microstructure with the passage of sintering time. The electrical conductivity of the Ag-Al nanopaste decreased as the stencil printed paste thickness increased between 25.4-101.6 microns. This was due to the much larger pore formation in the thicker nanopaste layers during sintering and organics burn off.

Conductive Fusion Technology Advanced Die Attach Materials for High Power Applications

2018 ◽  
Vol 2018 (HiTEC) ◽  
pp. 000051-000055
Author(s):  
Maciej Patelka ◽  
Nicholas Krasco ◽  
Sho Ikeda ◽  
Toshiyuki Sato ◽  
Miguel Goni ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
High Power ◽  
High Performance ◽  
High Reliability ◽  
High Thermal Conductivity ◽  
Fusion Technology ◽  
Power Semiconductor ◽  
Die Attach ◽  
Sintered Silver

Abstract High power semiconductor applications require a die attach material with high thermal conductivity to efficiently release the heat generated from these devices. Current die attach solutions such as eutectic solders and high thermal conductive silver epoxies and sintered silver adhesives have been industry standards, however may fall short in performance for high temperature or high stress applications. This presentation will focus on development of a reinforced, sintered silver die attach solution for high power semiconductor applications with focus on a pressure-less, low temperature sintering technology that offers high reliability for high temperature (250°C) applications. The electronic, optoelectronic, and semiconductor industries have the need for high performance adhesives, in particular, high power devices require low-stress, high thermal conductivity, thermally stable, and moisture resistant adhesives for the manufacture of high reliability devices. This paper introduces a new reinforced sintered silver adhesive based on the “resin-free” Conductive Fusion Technology. The high performance adhesive offers a robust solution for high temperature, high reliability applications. Conductive Fusion Technology consists of a high thermal conductivity silver component blended with a non-conductive, low-modulus powder component. The non-conductive powder component comprises an organically modified inorganic material that exhibits excellent thermal stability at temperatures exceeding 250°C. Properties of the sintered silver adhesive, such as storage modulus, can be modified by varying the content of the non-conductive component.

New Generation of SiC Based Biodevices Implemented on 4” Wafers

2010 ◽  
Vol 645-648 ◽  
pp. 1097-1100 ◽  
Author(s):  
Phillippe Godignon ◽  
Iñigo Martin ◽  
Gemma Gabriel ◽  
Rodrigo Gomez ◽  
Marcel Placidi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Silicon Carbide ◽  
High Temperature ◽  
Temperature Sensors ◽  
Biomedical Devices ◽  
Power Semiconductor ◽  
Power Semiconductor Devices ◽  
New Generation ◽  
Growth Technology ◽  
Biosensor Applications

Silicon Carbide is mainly used for power semiconductor devices fabrication. However, SiC material also offers attractive properties for other types of applications, such as high temperature sensors and biomedical devices. Micro-electrodes arrays are one of the leading biosensor applications. Semi-insulating SiC can be used to implement these devices, offering higher performances than Silicon. In addition, it can be combined with Carbon Nanotubes growth technology to improve the devices sensing performances. Other biosensors were SiC could be used are microfluidic based devices. However, improvement of SiCOI starting material is necessary to fulfill the typical requirements of such applications.

Sandwich Structured Power Module for High Temperature SiC Power Semiconductor Devices

2014 ◽  
Vol 2014 (1) ◽  
pp. 000757-000762 ◽  
Author(s):  
Takeshi ANZAI ◽  
Yoshinori MURAKAMI ◽  
Shinji SATO ◽  
Hidekazu TANISAWA ◽  
Kohei HIYAMA ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Semiconductor Devices ◽  
Ceramic Substrate ◽  
Power Module ◽  
Power Semiconductor ◽  
Power Semiconductor Devices ◽  
High Temperature Operation

A high temperature sandwich structured power module for high temperature SiC power semiconductor devices has been accomplished. Problems were found in the high temperature building-up process of the module caused by excess warpage of the ceramic substrate. Also the high temperature operation of the power module brings an excess warpage of the structure caused by parts having different coefficients of thermal expansion (CTEs) from each other. In this paper, some countermeasures to overcome the problems are demonstrated.

Simulation Analysis of Snubber Circuit for SiC MOSFET Inverter

2014 ◽  
Vol 1070-1072 ◽  
pp. 1241-1245
Author(s):  
Li Jun Xie ◽  
Xian Zheng Liu ◽  
Jin Yuan Li ◽  
Kun Shan Yu
Keyword(s):  
High Temperature ◽  
High Voltage ◽  
High Frequency ◽  
Simulation Analysis ◽  
Pwm Inverter ◽  
Parasitic Inductance ◽  
Power Semiconductor ◽  
Power Semiconductor Devices ◽  
Snubber Circuit ◽  
Parasitic Parameters

SiC MOSFET, as a promising power semiconductor devices, has attracted attention from many laboratories and companies for its super performance in high temperature, high voltage and high frequency applications. To protect the devices from overvoltage induced by parasitic inductance in high frequency applications, snubber circuit is a must. In this paper, simulation of snubber circuit in a high frequency PWM inverter is invested, under different numbers of snubber circuit , parasitic parameters, different kinds of load and whether a SiC SBD exsits. Some useful conclusions are obtained to help design more perfect snubber circuit.

High-Temperature Characterization and Comparison of 1.2 kV SiC Power Semiconductor Devices

2013 ◽  
Vol 10 (4) ◽  
pp. 138-143 ◽  
Author(s):  
Christina DiMarino ◽  
Zheng Chen ◽  
Dushan Boroyevich ◽  
Rolando Burgos ◽  
Paolo Mattavelli
Keyword(s):  
High Temperature ◽  
Semiconductor Devices ◽  
Wide Bandgap ◽  
Current Gain ◽  
Dynamic Characterization ◽  
Power Semiconductor ◽  
Power Semiconductor Devices ◽  
Unbiased Manner ◽  
Insight Into

Focused on high-temperature (200°C) operation, this paper seeks to provide insight into state-of-the-art 1.2 kV silicon carbide (SiC) power semiconductor devices; namely the MOSFET, BJT, SJT, and normally-off JFET. This is accomplished by characterizing and comparing the latest generation of these wide bandgap devices from various manufacturers (Cree, GE, ROHM, Fairchild, GeneSiC, and SemiSouth). To carry out this study, the static and dynamic characterization of each device is performed under increasing temperatures (25–200°C). Accordingly, this paper describes the experimental setup used and the different measurements conducted, which include: threshold voltage, current gain, specific on-resistance, and the turn-on and turn-off switching energies of the devices. The driving method used for each device is also detailed. Key trends and observations are reported in an unbiased manner throughout the paper and summarized in the conclusion.

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