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.

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.

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.

Layered Compound Semiconductor GaSe and GaTe Crystals for THz Applications

2006 ◽  
Vol 969 ◽  
Author(s):  
Krishna C. Mandal ◽  
Sung H. Kang ◽  
Michael K. Choi
Keyword(s):  
Wide Band ◽  
Optical Quality ◽  
Layered Compound ◽  
Bridgman Technique ◽  
Wide Band Gap ◽  
Long Term Stability ◽  
Vertical Bridgman ◽  
Thz Applications ◽  
Good Optical Quality

AbstractThe single crystal growth of layered semiconductors GaSe and GaTe by vertical Bridgman technique using zone refined selenium (Se), tellurium (Te) and high purity (HP) gallium (Ga) have been described. The grown crystals (2.5 cm diameter and ∼10 cm long) have demonstrated efficient broadband tunable THz emission and as sensitive THz detectors. The crystals have shown promising characteristics with good optical quality, high dark resistivity, wide band gap (GaSe-2.01 eV and GaTe-1.66 eV at 300 K), good anisotropic (parallel, p & perpendicular, pa) electrical properties (σ∥ vs σ⊥ and μ∥ vs σ⊥) and long term stability. Different steps involved in processing GaSe and GaTe crystals as THz sources and sensors are described.

Package Design and Analysis for Vertical Gallium Nitride Field Effect Transistors

2021 ◽  
Vol 2021 (HiTEC) ◽  
pp. 000058-000063
Author(s):  
John Harris ◽  
David Huitink ◽  
Dan Ewing
Keyword(s):  
Gallium Nitride ◽  
High Temperature ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Wide Band ◽  
Development Stage ◽  
Wide Band Gap ◽  
Package Design ◽  
Bulk Gan ◽  
Effect Transistor

Abstract Gallium nitride (GaN) is a wide band gap semi-conductor with superior electron mobility to silicon carbide. These properties allow for the design of high temperature capable devices with excellent on resistance and breakdown voltage for their size. However, bulk GaN is difficult to fabricate and doping for field effect transistor (FET) control has been elusive, so vertical GaN devices are not commonplace. This paper measures the characteristics of vertical GaN FETs in the development stage and discusses packaging them for fabrication feedback and for future high temperature aplications.

scholarly journals Heat-Resistant Microporous Ag Die-Attach Structure for Wide Band-Gap Power Semiconductors

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2531 ◽  
Author(s):  
Seungjun Noh ◽  
Hao Zhang ◽  
Katsuaki Suganuma
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
Morphological Evolution ◽  
Void Formation ◽  
Wide Band ◽  
Thermal Reliability ◽  
Power Semiconductors ◽  
Die Attach ◽  
Ag Paste ◽  
Sintered Ag

In this work, efforts were made to prepare a thermostable die-attach structure which includes stable sintered microporous Ag and multi-layer surface metallization. Silicon carbide particles (SiCp) were added into the Ag sinter joining paste to improve the high-temperature reliability of the sintered Ag joints. The use of SiCp in the bonding structures prevented the morphological evolution of the microporous structure and maintained a stable structure after high temperature storage (HTS) tests, which reduces the risk of void formation and metallization dewetting. In addition to the Ag paste, on the side of direct bonded copper (DBC) substrates, the thermal reliability of various surface metallizations such as Ni, Ti, and Pt were also evaluated by cross-section morphology and on-resistance tests. The results indicated that Ti and Pt diffusion barrier layers played a key role in preventing interfacial degradations between sintered Ag and Cu at high temperatures. At the same time, a Ni barrier layer showed a relatively weak barrier effect due to the generation of a thin Ni oxide layer at the interface with a Ag plating layer. The changes of on-resistance indicated that Pt metallization has relatively better electrical properties compared to that of Ti and Ni. Ag metallization, which lacks barrier capability, showed severe growth in an oxide layer between Ag and Cu, however, the on-resistance showed fewer changes.

HIGH FREQUENCY, HIGH TEMPERATURE FIELD-EFFECT TRANSISTORS FABRICATED FROM WIDE BAND GAP SEMICONDUCTORS

1995 ◽  
Vol 06 (01) ◽  
pp. 211-236 ◽  
Author(s):  
R.J. TREW ◽  
M.W. SHIN
Keyword(s):  
High Temperature ◽  
Band Gap ◽  
Microwave Power ◽  
High Frequency ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Wide Band ◽  
Superior Performance ◽  
Wide Band Gap ◽  
Wide Band Gap Semiconductors

Electronic and optical devices fabricated from wide band gap semiconductors have many properties ideal for high temperature, high frequency, high power, and radiation hard applications. Progress in wide band gap semiconductor materials growth has been impressive and high quality epitaxial layers are becoming available. Useful devices, particularly those fabricated from SiC, are rapidly approaching the commercialization stage. In particular, MESFETs (MEtal Semiconductor Field-Effect Transistors) fabricated from wide band gap semiconductors have the potential to be useful in microwave power amplifier and oscillator applications. In this work the microwave performance of MESFETs fabricated from SiC, GaN and semiconducting diamond is investigated with a theoretical simulator and the results compared to experimental measurements. Excellent agreement between the simulated and measured data is obtained. It is demonstrated that microwave power amplifiers fabricated from these semiconductors offer superior performance, particularly at elevated temperatures compared to similar components fabricated from the commonly employed GaAs MESFETs.

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