Test Results of Sintered Nanosilver Paste Die Attach for High-Temperature Applications

2016 ◽  
Vol 13 (1) ◽  
pp. 6-16 ◽  
Author(s):  
Paul Croteau ◽  
Sayan Seal ◽  
Ryan Witherell ◽  
Michael Glover ◽  
Shashank Krishnamurthy ◽  
...  
Keyword(s):  
High Temperature ◽  
Cooling System ◽  
Wide Band ◽  
Power Converter ◽  
Test Results ◽  
Wide Band Gap ◽  
Strain Behavior ◽  
Die Attach ◽  
Nanosilver Paste ◽  
Sintered Silver

The emergence of wide band gap devices has pushed the boundaries of power converter operations and high power density applications. It is desirable to operate a power inverter at high switching frequencies to reduce passive filter weight and at high temperature to reduce the cooling system requirement. Therefore, materials and components that are reliable at temperatures ranging from −55°C to 200°C, or higher, are needed. Sintered silver is receiving significant attention in the power electronic industry. The porous nature of sintered nanosilver paste with a reduced elastic modulus has the potential to provide strain relief between the die component and substrate while maintaining its relatively high melting point after sintering. The test results presented herein include tensile testing to rupture of sintered silver film to characterize stress-strain behavior, as well as die shear and thermal cyclic tests of sintered silver-bonded silicon die specimens to copper substrates to determine shear strength and reliability.

Test Results of Sintered Nano-Silver Paste Die Attach for High Temperature Applications

2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 000037-000049
Author(s):  
Paul Croteau ◽  
Sayan Seal ◽  
Ryan Witherell ◽  
Michael Glover ◽  
Shashank Krishnamurthy ◽  
...  
Keyword(s):  
High Temperature ◽  
Cooling System ◽  
Wide Band ◽  
Power Converter ◽  
Test Results ◽  
Silver Paste ◽  
Nano Silver ◽  
Strain Behavior ◽  
Die Attach ◽  
Sintered Silver

The emergence of wide band gap devices has pushed the boundaries of power converter operations and high power density applications. It is desirable to operate a power inverter at high switching frequencies to reduce passive filter weight and at high temperature to reduce the cooling system requirement. Therefore, materials and components that are reliable at temperatures ranging from −55 to 200 °C, or higher, are needed. Sintered silver is receiving significant attention in the power electronic industry. The porous nature of sintered nano-silver paste with a reduced elastic modulus has the potential to provide strain relief between the die component and substrate while maintaining its relatively high melting point after sintering. The test results presented herein include tensile testing to rupture of sintered silver film to characterize stress strain behavior, as well as die shear and thermal cyclic tests of sintered silver bonded silicon die specimens to copper substrates to determine shear strength and reliability.

Design and Testing of a High Temperature Inverter

2016 ◽  
Vol 2016 (HiTEC) ◽  
pp. 000175-000179
Author(s):  
Shashank Krishnamurthy ◽  
Stephen Savulak ◽  
Yang Wang
Keyword(s):  
High Temperature ◽  
Cooling System ◽  
Wide Band ◽  
Power Converter ◽  
Power Module ◽  
Paper Test ◽  
Drive Power ◽  
Component Selection ◽  
Variable Voltage ◽  
Functional Components

Abstract The emergence of wide band gap devices has pushed the boundaries of power converter operations and high power density applications. It is desirable to operate a power inverter at high switching frequencies to reduce passive filter weight and at high temperature to reduce the cooling system requirement. The paper describes the design and test of a power electronic inverter that converts a fixed input DC voltage to a variable voltage variable frequency three phase output. The component selection and design were constrained such that the inverter can operate at an ambient temperature of 170°C. The design of the key functional components such as the gate drive, power module, controller and communication will be discussed in the paper. Test results for the inverter at high temperature will also be presented.

Performance of commercial SOI driver in harsh conditions (up to 200°C)

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000054-000057
Author(s):  
K. El Falahi ◽  
B. Allard ◽  
D. Tournier ◽  
D. Bergogne
Keyword(s):  
Cooling System ◽  
Wide Band ◽  
Silicon On Insulator ◽  
Junction Temperature ◽  
Test Results ◽  
Wide Band Gap ◽  
Ambient Temperatures ◽  
Power Modules ◽  
Harsh Conditions

Power electronics based on wide band gap materials, such as silicon carbide (SiC) or gallium nitride (GaN), are nowadays capable of operation at increased ambient temperatures. High Temperature Intelligent Power Modules are unfortunately not available due to a lack of integrated driver able to withstand either harsh environment or enhanced junction temperature due to reduction in the cooling system. The most appropriated technology for such a driver seems to be Silicon on Insulator (SOI). The maximum operating temperature of commercial SOI devices with conventional packaging is usually 150°C up to 175°C as specified by manufacturers. In this paper, we actually try to observe the performance and de-ratings of these SOI circuits at temperatures above 175°C. Experimental characterization of commercial SOI MOSFET drivers from room temperature to 200°C and beyond is presented. Parameters such as output current amplitude, delay time, rise time and fall time of the output waveforms of the drivers are monitored. The test results will be discussed, and will help produce the specifications of an integrated SOI-based core-driver with the necessary functionalities to drive an inverter up to 220°C ambient temperature.

High Temperature Lead-Free Attach Reliability

2007 ◽  
Author(s):  
Patrick McCluskey ◽  
Pedro O. Quintero
Keyword(s):  
High Temperature ◽  
Wide Band ◽  
Wide Band Gap ◽  
Physics Of Failure ◽  
Electronic Products ◽  
Failure Modeling ◽  
Die Attach ◽  
Increasing Demand ◽  
Accelerated Thermal Cycling

The increasing demand for electronics capable of operating at temperatures above the traditional 125°C limit is driving major research efforts. Wide band gap semiconductors have been demonstrated to operate at temperatures up to 500°C, but packaging is still a major hurdle to product development. Recent regulations, such as RoHS and WEEE, increase the complexity of the packaging task as they prohibit the use of toxic materials in electronic products; lead being a major concern due to its widespread use in solder attach. In this investigation, a series of Pb-free die attach technologies have been identified as possible alternatives to Pb-based materials for high temperature applications. This paper describes the fabrication sequence used to create attachments with these materials and their resultant microstructure. The long term reliability is also determined by accelerated thermal cycling and physics-of-failure modeling.

High Temperature Silicon Carbide CMOS Integrated Circuits

2011 ◽  
Vol 679-680 ◽  
pp. 726-729 ◽  
Author(s):  
David T. Clark ◽  
Ewan P. Ramsay ◽  
A.E. Murphy ◽  
Dave A. Smith ◽  
Robin. F. Thompson ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Integrated Circuits ◽  
Band Gap ◽  
High Temperatures ◽  
Wide Band ◽  
Cmos Technology ◽  
Cmos Integrated Circuits ◽  
Wide Band Gap ◽  
Circuit Performance

The wide band-gap of Silicon Carbide (SiC) makes it a material suitable for high temperature integrated circuits [1], potentially operating up to and beyond 450°C. This paper describes the development of a 15V SiC CMOS technology developed to operate at high temperatures, n and p-channel transistor and preliminary circuit performance over temperature achieved in this technology.

Metallurgy for SiC Die Attach for Operation at 500°C

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000008-000017 ◽  
Author(s):  
Ping Zheng ◽  
Phillip Henson ◽  
R. Wayne Johnson ◽  
Liangyu Chen
Keyword(s):  
High Temperature ◽  
Thick Film ◽  
Failure Surface ◽  
Nano Particle ◽  
Test Results ◽  
Shear Tests ◽  
Die Attach ◽  
Film Layer ◽  
Potential Failure ◽  
Dc Bias

Metallurgy for high temperature SiC die attach involves the substrate metallization, die metallization, and die attach material. This paper examines off-eutectic Au-Sn as the die attach alloy with a PtAu thick film metallization on AlN substrates. A pure Au thick film layer was printed over the PtAu thick film layer. The SiC backside metallizations evaluated were Ti/TaSi/Pt/Au and Cr/NiCr/Au. Die shear tests were performed after aging at 500°C and after thermal cycling. The shear test results and failure surface analysis are discussed. Nanoparticle Ag and liquid transient phase bonding with Ag based metallurgies have been proposed for high temperature die attach. Data on the migration of sintered nano-particle Ag and thin film Ag dc bias during storage in air at 300°C and 375°C are presented. Migration of Ag is a potential failure mechanism for Ag based high temperature metallurgies.

Study of Thermal Stress in Nano Silver Bonded Silicon Substrates for High Temperature Applications

2019 ◽  
Vol 2019 (HiTen) ◽  
pp. 000052-000055
Author(s):  
G.D. Liu ◽  
C.H. Wang
Keyword(s):  
Thermal Stress ◽  
High Temperature ◽  
Silver Layer ◽  
Silicon Substrates ◽  
The Finite Element Method ◽  
Nano Silver ◽  
Silicon Chips ◽  
Die Attach ◽  
The Relationship ◽  
Sintered Silver

Abstract The silver nanoparticle paste is a promising material for high temperature die-attach applications. In this paper, the finite element method is used to study the relationship between the thickness of the sintered silver layer and the thermal stress in the sintered silver joint. Silicon chips are bonded together with sintered silver layers of different thicknesses. In the experimental study, strain gauges are attached onto the surface of the upper silicon and used to estimate the effects of the nano silver die-attach layer. The results show that the average stress in the silver layer at the interface decreases with the increasing thickness of the silver layer, while the stress on the silicon surface increases with the increasing thickness of the silver layer.

Sintered Silver Die Attach with Extreme Thermal Stability for Extreme and Dynamic Environments

2017 ◽  
Vol 2017 (HiTEN) ◽  
pp. 000168-000176 ◽  
Author(s):  
Khalid Khtatba ◽  
Seyed Amir Paknejad ◽  
Ali Mansourian ◽  
Samjid H. Mannan
Keyword(s):  
High Temperature ◽  
Surface Oxidation ◽  
Migration Route ◽  
Oxidation Treatment ◽  
Contact Metallization ◽  
Die Attach ◽  
High Temperature Storage ◽  
Internal Pore ◽  
Temperature Storage ◽  
Sintered Silver

Abstract: The surface oxidation of internal pore surfaces of nano-scale sintered silver has increased stability for high temperature applications. After treatment, high temperature storage at 400 °C has resulted in no changes to microstructure. By contrast, it is known that the microstructure of untreated pressure-less sintered silver continuously evolves at temperatures above 200 °C. Grain and pore growth occur in this temperature range for conventional sintered silver resulting in coarsening of the microstructure and increased susceptibility to fatigue. However, oxidation treatment of the internal pore surfaces has the effect of freezing the microstructure when the contact metallization is also silver or chemically inert. Oxidation prevents mass transfer by shutting down the fastest atomic migration route along the internal pore surfaces. Samples exhibited no change in microstructure either through continuous observation through glass, or after cross sectioning. The tested specimens under high temperature storage resisted grain growth for the whole duration of the tests of more than 600 h at 300 °C. The only detectable changes in microstructure occurred in a sparse number of isolated grains (1 in 7000 grains), presumably due to non-penetration of oxidising treatment into these closed pore spaces. It is hypothesized that even these can be prevented by minor changes to the sintering paste to slightly increase initial porosity. The oxidising treatment can be performed via many different routes, such as exposure to steam, or even by dipping in water for 10 min.

Microstructure and Mechanical Properties of Pressureless Sintered Silver Die-attach Materials

2018 ◽  
Vol 2018 (1) ◽  
pp. 000602-000605
Author(s):  
Tomofumi Watanabe ◽  
Keisuke Tanaka ◽  
Masafumi Takesue
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Physical And Mechanical Properties ◽  
External Pressure ◽  
Exposure Test ◽  
High Temperature Exposure ◽  
Die Attach ◽  
Temperature Exposure ◽  
Substantial Change ◽  
Sintered Silver

Abstract Microstructural and mechanical properties of a pressureless sintered silver material were measured. The Microstructure of the pressureless sintered silver material had pores of less than 1 μm in size and some silver matrices sintered with nanoparticles between each other. The pressureless sintered silver material could be bonded on bare copper without applying an external pressure. After subjecting the material to a high temperature exposure test at 250 °C and for 1000 h, it showed no substantial change in microstructure and showed a constant Young's modulus of 14 GPa. The pressureless sintered silver material in this work did not show any embrittlement or increase in pore size after the high temperature exposure test, which demonstrated that the material has reliable physical and mechanical properties at temperatures up to 250 °C.

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