Direct Palladium-Gold on copper as a Surface Finish for next generation Packages.

2013 ◽  
Vol 2013 (DPC) ◽  
pp. 001145-001184
Author(s):  
Mustafa Ozkok ◽  
Sven Lamprecht ◽  
Gustavo Ramos ◽  
Arnd Kilian
Keyword(s):  
Surface Finish ◽  
Copper Wire ◽  
Environmental Issues ◽  
Wire Bonding ◽  
Gold Layer ◽  
Test Results ◽  
Fine Line ◽  
Surface Finishes ◽  
Copper Wire Bonding ◽  
Bond Tests

A new surface finish is entering the market. The need for this finish comes from needs for new assembly technologies like copper wire bonding or chip assembly by thermo compression bond. Furthermore Nickel an element, which is the base of many surface finishes like ENIG or ENEPIG, is more and more regarded as an unpleasant element as of several disadvantages, such as for high frequency applications, for environmental issues or for fine line applications were a 5 μm Ni Layer is just simply too thick. All these concerns supporting the introduction of a new surface finish, a direct EP and direct EPAG finish. In particular, its suitability for copper wire bonding and its fine line capability makes it very attractive from a cost standpoint of view. In addition, the mentioned technological handicaps of nickel based finishes could be solved by applying a revolutionary surface finish – A Direct Palladium with an optional gold layer. The direct deposition of palladium on copper with an optional gold layer does have further technological, environmental and economical advantages. The suggested paper will describe and discuss the advantages and chances using this new surface finish, as well as demonstrate soldering on various wire bond tests on the Direct EP and EPAG finishes as well as soldering test results.

Advanced Surface Finishes for Ceramic Electronics for Soldering, Conductive Adhesive, Aluminum- , Gold-, and Copper Wire Bonding.

2013 ◽  
Vol 2013 (CICMT) ◽  
pp. 000257-000260
Author(s):  
Maren Bruder ◽  
Guenter Heinz ◽  
Mustafa Oezkoek
Keyword(s):  
Surface Finish ◽  
Copper Wire ◽  
Economic Benefits ◽  
Wire Bonding ◽  
Gold Layer ◽  
Ceramic Substrates ◽  
Main Layer ◽  
Surface Finishes ◽  
Copper Wire Bonding ◽  
Assembly Technology

Surface finishes for ceramic electronics are an important feature. . The suitable surface finish allows the appropriate assembly technology to be performed on the ceramic substrate. The paper will present the possible surface finish options for ceramic substrates and include the advantages and challenges of each surface finish. Furthermore it will show the potential of a new surface finish called “Direct EPAG”. The demand for these new finishes is based on needs for new assembly technologies like copper wire bonding and for high frequency applications. Furthermore Nickel which the main layer of many surface finishes like ENIG or ENEPIG, is more and more regarded as an unpleasant element due to several disadvantages. All these concerns are supporting the introduction of a new surface finish called “direct EPAG” (Electroless Palladium, Autocatalytic Gold) finish. In particular, its suitability for copper wire bonding and its fine line capability makes it very attractive from a cost standpoint. In addition, the mentioned technological drawbacks of nickel based finishes could be solved by applying a revolutionary surface finish: “direct palladium with an optional direct gold layer on copper”. The direct deposition of palladium on copper with an optional gold layer does have a number of technological, environmental and economic benefits. The suggested paper will describe and discuss the advantages and challenges using this new surface finish. It will also exhibit the results of various soldering and wire bond tests on the EPAG finish.

Ageing characteristics of Cu Wire Bonds on Palladium Surface Finishes

2011 ◽  
Vol 2011 (1) ◽  
pp. 000566-000570
Author(s):  
Mustafa Oezkoek ◽  
Horst Clauberg ◽  
Hugh Roberts
Keyword(s):  
Surface Finish ◽  
Thermal Aging ◽  
Copper Wire ◽  
Pure Copper ◽  
Wire Bonding ◽  
Throughput Optimization ◽  
Wire Bond ◽  
Surface Finishes ◽  
Copper Wire Bonding ◽  
Pure Cu

During the past two years, fine pitch copper wire bonding has finally entered high volume production. It is estimated that nearly 15% of all wire bonders used in production are now equipped for copper wire bonding. Most of these are used exclusively for copper wire bonding. In terms of pitch, copper wire is only barely lagging behind the most advanced gold applications. The most commonly used copper wire is 20um in diameter and 18um copper wire is already being used in mass production. Evaluations with even finer wire are underway. Although some technical challenges remain, many years of research have now resolved most of the problems associated with copper wire bonding and attention is beginning to shift from merely ensuring reliable manufacturing processes to optimizing processes for efficiency and throughput. The most advanced wire bonders now have pre-configured processes specifically designed for copper. In addition to throughput optimization, further cost reductions are being sought. Among these is the desire to eliminate the high-cost gold not just from the wire, but also from the substrate. On the substrate side the electronics packaging industry still works with electrolytic nickel / electrolytic (soft) gold (Ni/Au) for copper wire bond applications. This surface finish works with copper wire bonding but includes some disadvantages, such as:- Thick expensive Au layers of 0.1 to 0.4μm- Electrically connected pads (bussing for the plating) which requires added space on the substrate.- Pd-coated copper wire often delivers better results on gold covered finishes, but is two to three times more expensive as pure copper wire Furthermore electrolytic Ni/Au was not chosen for Cu wire bonding as a result of in-depth investigations for the most effective surface finish. The selection was made because it was the surface finish with the highest distribution in the market for wire bond packages. This paper is offering the results of a two company joint work regarding alternative copper wire bondable surface finishes. The result of the project is separated in 2 papers/publications. The first publication [1] presents the investigations with Cu wire bond pull forces and process windows of 23 different surface finish variations. The main aim was to identify alternative surface finishes for copper wire bonding. Within this study the surface finishes ENEP (Electroless Nickel/Electroless Palladium) and “Direct Electroless pure Pd on copper” (pure EP finish) was identified as copper wire bondable finishes with the pure Cu wire. The second part of the evaluation summarizes an in-depth study of copper wire bonding tests after thermal aging with ENEP and the pure EP surface finish using the pure copper wire. The results of this investigation does include results with pull forces after thermal aging and an IMC Investigation with FIB Pictures of the copper wire/surface finish connection in order to evaluate the reliability of such an interconnection.

Direct EP/EPAG - Ultrathin Surface Finish for Soldering and Wire Bonding

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 001328-001360
Author(s):  
Mustafa Oezkoek ◽  
Gustavo RamosArnd ◽  
KilianJens Wegricht
Keyword(s):  
Solder Joint ◽  
Surface Finish ◽  
Copper Wire ◽  
Wire Bonding ◽  
Solder Joint Reliability ◽  
Joint Reliability ◽  
Gold Silver ◽  
Copper Wire Bonding ◽  
Packaging Industry ◽  
New Challenges

New challenges in the industry, new technical requirements, as well as cost and environmental regulations, require a constant search for alternative manufacturing solutions for the electronic packaging industry. Finer lines and spaces, higher frequencies, improved solder joint reliability and new challenges in wire bonding – both with existing wire technology such as Al and Au or novel types such as Cu or Cu-Pd – are just a few examples of technological advancements for surface finishes in the packaging industry. Additionally, the reduction and elimination of toxic and hazardous materials, as well as the drive to further reduce the manufacturing costs, are important requirements which has to be addressed. The new direct pure EP/EPAG surface finish is suggested as a solution to these challenges for the future. The direct EP/EPAG process allows the direct deposition of palladium on copper, without using any nickel. It is suitable for high frequency, for flexible applications, for gold, aluminum, gold, silver and copper wire bonding applications. The process proves superior solder joint strength for lead free and eutectic soldering and is compatible with many new base materials and soldermask types owing to its short deposit time and low temperature needs. Finally, the EP/EPAG process operates at a thickness of less than 300 nm, ideal for very fine lines and spaces. The EP/EPAG finish also features several environmental benefits, such as less water and energy consumption owing to reduced process steps and line lengths. The suggested paper will provide new wire bond data with silver, gold and copper wire bonding results. A technical comparison to a thin ENEPIG finish will be provided to show the differences in terms of soldering and solder joint reliability.

Failure Analysis on Power Trench MOSFET Devices with Copper Wire Bonds

2011 ◽  
Author(s):  
Huixian Wu ◽  
Arthur Chiang ◽  
David Le ◽  
Win Pratchayakun
Keyword(s):  
Failure Analysis ◽  
Copper Wire ◽  
New Technology ◽  
Analytical Techniques ◽  
Wire Bonding ◽  
Bonding Process ◽  
Wire Bonds ◽  
Copper Wire Bonding ◽  
Wet Chemical ◽  
Microelectronic Components

Abstract With gold prices steadily going up in recent years, copper wire has gained popularity as a means to reduce cost of manufacturing microelectronic components. Performance tradeoff aside, there is an urgent need to thoroughly study the new technology to allay any fear of reliability compromise. Evaluation and optimization of copper wire bonding process is critical. In this paper, novel failure analysis and analytical techniques are applied to the evaluation of copper wire bonding process. Several FA/analytical techniques and FA procedures will be discussed in detail, including novel laser/chemical/plasma decapsulation, FIB, wet chemical etching, reactive ion etching (RIE), cross-section, CSAM, SEM, EDS, and a combination of these techniques. Two case studies will be given to demonstrate the use of these techniques in copper wire bonded devices.

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
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