Critical Barriers Associated with Copper Wire

2015 ◽  
Vol 2015 (1) ◽  
pp. 000394-000398
Author(s):  
William G. Crockett
Keyword(s):  
High Reliability ◽  
Copper Wire ◽  
Automotive Electronics ◽  
Bonding Wire ◽  
Cu Alloy ◽  
Bonding Wires ◽  
Reducing Costs ◽  
Cu Bonding ◽  
Bonding Characteristics ◽  
Bare Copper

Since around 2008, the shift from Gold (Au) bonding wire to Copper (Cu) bonding wire has been taking place, full scale, with the aim of reducing costs. When compared with Au, Cu wire presents challenges in reliability and repeatable bonding characteristics in terms of chemical stability, which is required in high reliability applications. Therefore Cu wire adoption in automotive and industrial semiconductors has been limited. Conventionally the market for Cu bonding wires has been divided into two types: bare Cu wires (high purity) and Palladium coated copper (PCC) bonding wires. These wires have yet to satisfy the required characteristics for high reliability products such as industrial and automotive electronics. A new breed of alternative bonding wires has been developed to offer performance advantages for high reliability applications compared to bare copper wire and PCC wire. Cu alloy wire and Ag alloy wires continue their market introduction for advanced bonding applications, where bare Cu and PCC wires have known limitations.

Reliability Evaluation of Cu-Al WB in High Temperature and High Current Applications

2021 ◽  
Author(s):  
Pradeep Lall ◽  
Sungmo Jung
Keyword(s):  
High Temperature ◽  
High Reliability ◽  
Copper Wire ◽  
Planck Equation ◽  
Operating Conditions ◽  
Polarization Curves ◽  
Automotive Electronics ◽  
Wire Bonds ◽  
Chlorine Ions ◽  
Copper Aluminum

Abstract High reliability harsh environment applications necessitate a better understanding of the acceleration factors under operating stresses. Automotive electronics has transitioned to the use of copper wire for first level interconnects. A number of copper wire formulations have emerged including palladium coated copper and gold-flash palladium coated copper. The corrosion reliability of copper wire bonds in high temperature conditions is not yet fully understood. The EMC used to encapsulate chips and interconnects can vary widely in formulation, including pH, porosity, diffusion rate, composition of contaminants and contaminant concentration. To realistically represent the expected wirebond reliability, there is need for a predictive model that can account for environmental conditions, operating conditions, and exposure to EMCs. In this paper, different EMCs were studied in a high-temperature-current environment with temperature range of 60°C–100°C under current of 0.2A–1A. The diffusion kinetics based on the Nernst-Planck Equation for migration of the chlorine ions has been coupled with the Butler-Volmer equation for corrosion kinetics to create a Multiphysics model. Polarization curves have been measured for copper, aluminum and intermetallics under a number of pH values, and chlorine-ion concentrations. Tafel parameters have been extracted through measurements of the polarization curves.

On-Line Hardness Characterization of Novel 2-mil Copper Bonding Wires

2007 ◽  
Author(s):  
C. J. Hang ◽  
I. Lum ◽  
J. Lee ◽  
M. Mayer ◽  
Y. Zhou ◽  
...  
Keyword(s):  
Copper Wire ◽  
Comparison Study ◽  
Bonding Wire ◽  
Free Air ◽  
Ic Packaging ◽  
Bonding Wires ◽  
On Line ◽  
The Wire

In order to eliminate the chip cratering for copper wire applications in IC packaging, it is worthwhile to develop new Cu wire chemistries to obtain a soft copper wire with a soft free-air ball (FAB). The conventional hardness characterization of a new bonding wire is a labour intensive, time-consuming work. Therefore an on-line hardness characterization method is presented that enables the hardness comparison of a larger number of different wires within a shorter time. The influences of capillary change, bonding substrate metallization and temperature on this method is quantified. It is found these influences need to be held constant during a hardness comparison study. With this method, the wire and FAB hardness comparison of nine novel 2-mil copper bonding wires, Cu 1 to Cu 9, and one 2-mil Au wire are performed. The wire hardness (wireside) and FAB hardness are characterized. It is found that the Cu 4 and Cu 5 have the softest wireside hardness and FAB hardness.

scholarly journals Development of high reliability semiconductor devices by copper wire bonding.

1988 ◽  
Vol 27 (4) ◽  
pp. 299-301
Author(s):  
J. Hirota ◽  
Y. Shibutani ◽  
T. Sugimura ◽  
K. Machida ◽  
T. Okuda
Keyword(s):  
High Reliability ◽  
Copper Wire ◽  
Semiconductor Devices ◽  
Wire Bonding ◽  
Copper Wire Bonding

Reliability analysis of bonding wire based on stacked substrate packaging structure

2019 ◽  
Vol 2019 (1) ◽  
pp. 000603-000608
Author(s):  
Chi Zhang ◽  
Yifan Tan ◽  
Zhizhao Huang ◽  
Cai Chen ◽  
Yong Kang
Keyword(s):  
Thermal Cycling ◽  
Layer Thickness ◽  
Peak Height ◽  
Analytical Models ◽  
Bonding Wire ◽  
Module Design ◽  
Fast Switching ◽  
Calculation Results ◽  
Bonding Wires ◽  
Packaging Structure

Abstract The stacked substrate packaging technology is a new 3D power loop structure utilizing multiple layer DBC to achieve ultra-low parasitic for the fast switching SiC device. This structure has a different geometry on interconnection between chips and substrate contrasting to the conventional module design, which needs optimization on the interconnection for the reliability consideration of this new structure. Analytical models of different bonding wire shapes and DBC structures were developed to calculate the von-mise stress on each model under thermal cycling simulation. The simulation results show that the stress on bonding wire reaches minimum when welding point located at the center of the top DBC substrate and the stress decreases when DBC top copper layer thickness increases or ceramic layer thickness decreases. Moreover, bonding wires with smaller diameter, certain peak height and width show lower stress and strain. Furthermore, thermal cycling tests were done on samples with same geometries of analytical models, and the wire pull test results showed consistency with the stress calculation results which verifying the optimum wire shape and DBC structure for the stacked substrate packaging.

Aluminum Wedge-Wedge Bonding Using Capillary and Ball Bonder

2017 ◽  
Vol 2017 (1) ◽  
pp. 000444-000450
Author(s):  
Sarangapani Murali ◽  
Ei Phyu Phyu Theint ◽  
Hamdan Faizul Fitri ◽  
Tan Kean Tiong ◽  
Zhang Xi
Keyword(s):  
Gold Plating ◽  
Fine Ceramic ◽  
Cu Metallization ◽  
High Temperature Storage ◽  
Bonding Wires ◽  
Tensile Data ◽  
Substrate Surfaces ◽  
Wedge Bonding ◽  
Bare Copper ◽  
Temperature Storage

Abstract The paper discusses on the bondability and reliability of aluminum (Al) wedge-to-wedge bonding using fine ceramic capillary and ball bonder. Initial trials revealed aluminum build-up and poor capillary life with touch down of 20K or less. Optimizing the process parameters, switching on air-scrub, reducing shape angle to 20° instead of usual 35° and using Al-1wt%Si wire processed with refined grains revealed better capillary life with touch down of 200K without surface burrs. The method is capable of bonding complex looping and sharp acute bends. The data comprising of 1st and 2nd wedge dimensions, wedge pull, wedge shear and fracture mode for 20μm and 50μm Al-1wt%Si wires are presented. High temperature storage of aluminum wedge bonding to different substrate surfaces such as Al-0.5wt%Cu metallization, bare copper and gold plating revealed stable bond. From the wedge pull and tensile data, floor and shelf life of the wire is recommended to be 7days and 6months respectively. Evaluation of gold, copper and silver base bonding wires by this method showed feasible to bond and needs detailed studies to practice. The fusing current of Al-1wt%Si wire for varying diameter from 0.6 to 3mil and wire length from 1 to 20mm are also stated.

scholarly journals Development of Enhanced Bondability and Reliability Multi-Layer Cu Bonding Wire EX1

Materia Japan ◽  
2011 ◽  
Vol 50 (1) ◽  
pp. 30-32 ◽  
Author(s):  
Tomohiro Uno ◽  
Shinichi Terashima ◽  
Keiich Kimura
Keyword(s):  
Bonding Wire ◽  
Cu Bonding
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