Investigation into the Role of Different Substrate Ni Compositions and Plating Methods on Die Attach Reliability

2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 000073-000082
Author(s):  
Jinzi Cui ◽  
R. Wayne Johnson ◽  
Michael C. Hamilton
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
High Power ◽  
Diffusion Barrier ◽  
Die Attach ◽  
High Temperature Storage ◽  
The Impact ◽  
Direct Bond Copper ◽  
Temperature Storage

Nickel is a commonly used diffusion barrier for direct bond copper (DBC) substrates used in high temperature, high power applications. The Ni can be deposited by electroless or electrolytic plating and may be pure Ni, Ni:P, Ni:B or Ni:Co. The reactivity of these different Ni layers with AuGe and BiAgX® solder is explored. Specifically the reaction to form Ni-Ge intermetallics and NiBi3 during high temperature storage and the impact on die shear strength and failure mode are discussed.

Characterization of AgBiX™ Solder Paste on Thick Film for 200°C Applications

2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000340-000346 ◽  
Author(s):  
Zhenzhen Shen ◽  
Wayne Johnson ◽  
Michael C. Hamilton
Keyword(s):  
High Temperature ◽  
Thick Film ◽  
Solidus Temperature ◽  
Passive Component ◽  
Solder Paste ◽  
Die Attach ◽  
High Temperature Storage ◽  
Temperature Storage

AgBiX™ (Indium Corporation) solder paste has a solidus temperature of ∼262°C after reflow, which is suitable for passive component, semiconductor and power die attach for 200°C applications. In this work, the paste has been used to assemble SiC die with Ti/Ni/Ag thin film metallization to Ag and PdAg thick film substrates. High temperature storage testing (200°C) was preformed to characterize the reliability of the assemblies. Surface mount chip resistors attached to thick film substrates were also subject to high temperature storage. Comparisons of the performance of die attach and resistor attach on Ag substrates and PdAg substrates are made. EDX and failure analysis was used to understand the role of Pd on the failure mode and lower aged shear strengths with the thick film PdAg conductors.

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.

High reliable and high bonding strength of silver sintered joints on copper surfaces by pressure sintering under air atmosphere

2018 ◽  
Vol 2018 (1) ◽  
pp. 000434-000441
Author(s):  
Ly May Chew ◽  
Wolfgang Schmitt
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
Temperature Cycling ◽  
Acoustic Microscopy ◽  
Sintering Process ◽  
Copper Surfaces ◽  
Air Atmosphere ◽  
High Temperature Storage ◽  
Silver Sintering ◽  
Temperature Storage

Abstract Silver sintering is a promising die attach technology for high temperature power electronics packaging. Our previous studies have revealed that highly reliable sintered joints was obtained on silver and gold surfaces by either non-pressure or pressure sintering. In this paper, we extended our study to die attachment on copper surfaces by pressure sintering under air atmosphere. We attached Ag metallized die on silicon nitride active metal braze copper substrates with Ag metallization and without metallization by silver sintering at 230°C with a pressure of 10 MPa for 3 min. We observed that the average initial die shear strength for bare Cu substrate is lower than for Ag metallized substrate. This observation is attributed to the self-diffusion of Ag is faster than the interdiffusion between Ag and Cu. However, the average die shear strength for all samples increased considerably after temperature cycling test (−40°C/+150°C) and high temperature storage at 250°C. It is highly likely that sintering process is not yet completed under the sintering conditions used in this study and consequently Ag and Cu continued to diffuse during thermal cycling and high temperature storage and as a result strengthen the sintered joints. It is believed that after a certain time of storage at 250°C the sintering process is completed as we observed the average die shear strength remained relatively constant after 250 h storage. Voids, drying channels and delamination in the sintered joints were not detected by scanning acoustic microscopy for the samples before and after 2000 thermal cycles.

Failure Analysis of the Die-Attach in a Metal-Type Package

1996 ◽  
Author(s):  
J. Acki ◽  
A. Murakami ◽  
T. Akutsu ◽  
S. Matsuda ◽  
A. Maruyama ◽  
...  
Keyword(s):  
High Temperature ◽  
Alloy Layer ◽  
Storage Test ◽  
Power Mosfet ◽  
Package Design ◽  
Die Attach ◽  
Metal Type ◽  
High Temperature Storage ◽  
Space Projects ◽  
Temperature Storage

Abstract RECENTLY POWER MOSFETS have been used for satellite power supplies. NASDA has developed such a Power MOSFET for the space projects. It has a metal-type package, and the die is attached by Au-Si alloy to achieve high temperature operation (Tj=200°C). The fabricated device failure was detected thermal resistance tests after high temperature storage test at 200°C for 1000 hours. This failure is caused by the die peeling between the Au-Si eutectic alloy layer and the Ni plating surface on the Cu-W substrate. In this paper, we describe the failure mechanism and improvements in the package design and fabrication process. The newly developed power MOSFET for space use exhibits good performance in the high temperature storage test.

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