Pure Palladium and Palladium Phosphorus Depositions Used in ENEPIG and ENEP Surface Finishes – Comparison of Physical Properties and Their Influence on Soldering and Au Wire Bonding

2010 ◽  
Vol 2010 (1) ◽  
pp. 000675-000681 ◽  
Author(s):  
Mustafa Oezkoek ◽  
Hugh Roberts ◽  
Joe McGurran
Keyword(s):  
Physical Properties ◽  
Electroless Nickel ◽  
Gold Wire ◽  
Wire Bonding ◽  
Electroless Nickel Immersion Gold ◽  
Surface Finishes ◽  
Gold Thickness ◽  
Palladium Surface ◽  
Joint Integrity ◽  
Pure Palladium

As a surface finish, electroless nickel / electroless palladium / immersion gold (ENEPIG) has received increased attention for both packaging/IC-substrate and PWB applications. With a lower gold thickness compared to conventional electroless nickel / immersion gold (ENIG) the ENEPIG finish offers the potential for higher reliability, better performance and reduced cost.[1,2] This paper shows the benefits of using a pure palladium layer in ENEPIG and ENEP (Electroless Nickel / Electroless Palladium) surface finishes in terms of physical properties and in terms of gold wire bonding and solder joint integrity.

Thermosonic gold wire bonding to laminate substrates with palladium surface finishes

1999 ◽  
Vol 22 (1) ◽  
pp. 7-15 ◽  
Author(s):  
R.W. Johnson ◽  
M.J. Palmer ◽  
M.J. Bozack ◽  
T. Isaacs-Smith
Keyword(s):  
Gold Wire ◽  
Wire Bonding ◽  
Surface Finishes ◽  
Palladium Surface

A STUDY OF SURFACE FINISHES FOR IC SUBSTRATES AND WIRE BOND APPLICATIONS

2011 ◽  
Vol 2011 (1) ◽  
pp. 000516-000520 ◽  
Author(s):  
John Ganjei ◽  
Ernest Long ◽  
Lenora Toscano
Keyword(s):  
Surface Finish ◽  
Printed Circuit Boards ◽  
Performance Enhancement ◽  
High Reliability ◽  
Cost Effective ◽  
Electroless Nickel ◽  
Gold Wire ◽  
Electronics Industry ◽  
Surface Finishes ◽  
And Performance

The continuing drive for ever increasing performance enhancement in the electronics industry, in combination with the recent, very significant increase in precious metal costs have left fabricators and OEMs questioning what the best, most cost effective, surface finish is for high reliability applications. Currently, the IC substrate market relies heavily on electrolytic nickel and gold as a solderable and superior wire bondable surface. The use of this finish has allowed manufacturers to avoid the reliability concerns However, this choice also results in significant design restraints being imposed. Many in the industry are now investigating the use of electroless nickel/electroless palladium/immersion gold (ENEPIG) to achieve both high reliability and performance, without the negative design restraints imparted by the use of electrolytic processes. However, over the last year alone, the industry has watched the price of gold increase by 50% and that of palladium double [1]. With this in mind, and considering the historic precedent set in the mid 1990’s when ENEPIG was also evaluated as a surface finish for printed circuit boards, when coincidentally, the cost of palladium also reached an all time high, it should be remembered that the electronics industry quickly moved to evaluate alternate, more cost sustainable, surface finishes. This paper details the use of lower cost, alternate surface finishes for IC substrate applications, with particular experimental focus on gold wire bonding capabilities and BGA solderability of the finishes described. The paper also discusses related process cycle advantages and the significantly reduced operating costs associated with these new finishes.

Chemical Bath Temperature Investigation for Electroless Nickel Immersion Gold

2014 ◽  
Vol 925 ◽  
pp. 96-100
Author(s):  
Vithyacharan Retnasamy ◽  
Zaliman Sauli ◽  
Uda Hashim ◽  
Aaron Koay Terr Yeow ◽  
Steven Taniselass ◽  
...  
Keyword(s):  
Electroless Nickel ◽  
Bath Temperature ◽  
Gold Wire ◽  
Process Time ◽  
Reflow Process ◽  
Bump Height ◽  
Electroless Nickel Immersion Gold ◽  
Solder Bumps ◽  
Higher Temperature ◽  
Bond Pads

Conventional gold wire bonding to alunimium bond pads leads to the formation of intermetallic compound. Electroless Nickel Immersion Gold (ENIG) has been proposed as surface finish for aluminium bond pads to improve high temperature reliability. In order to create acceptable solder bumps prior to reflow process, a particular bump height for ENIG bumps need to be obtained. This paper reports the effects of chemical bath temperature in response to the bump height using a shorter process time. Analysis was done by using a design of experiment (DOE). The results suggest that higher temperature increases the bump height. Electroless nickel temperature has more influence to the bump height compared to immersion gold temperature.

Effects of Temperature–Humidity Treatment on Bending Reliability of Epoxy Sn–58Bi Solder with Electroless Nickel Immersion Gold (ENIG) and Electroless Nickel Electroless Palladium Immersion Gold (ENEPIG) Surface Finishes

2020 ◽  
Vol 12 (4) ◽  
pp. 564-570
Author(s):  
Haksan Jeong ◽  
Choong-Jae Lee ◽  
Woo-Ram Myung ◽  
Kyung Deuk Min ◽  
Seung-Boo Jung
Keyword(s):  
Intermetallic Compound ◽  
Solder Joint ◽  
Solder Joints ◽  
Solder Matrix ◽  
Electroless Nickel ◽  
Bending Test ◽  
Three Point Bending ◽  
Electroless Nickel Immersion Gold ◽  
Surface Finishes ◽  
Effects Of Temperature

An epoxy Sn–58wt.%Bi solder joint was evaluated by a three-point bending test with electroless nickel immersion gold (ENIG) and electroless nickel electroless palladium immersion gold (ENEPIG) surface finishes aged at 85 °C and 85% relative humidity. Scanning electron microscopy and electron probe microanalysis were carried out to study intermetallic compound variation. The morphology, total thickness, and chemical composition of intermetallic compound in epoxy Sn58Bi solder joints were the same as those of Sn–58wt.%Bi solder joints with each surface finish. The average number of bending-to-failure cycles for the epoxy Sn–58wt.%Bi solder/ENIG joints and epoxy Sn–58wt.%Bi solder/ENEPIG was more than 4000 and 5000, respectively. The average number of bending-to-failure cycles of the epoxy Sn–58wt.%Bi solder joint decreased with increasing age. Three-point bending reliability of epoxy Sn–58wt.%Bi solder joints was higher than that of Sn–58wt.%Bi solder with both surface finishes. Cracking of all solder joints subjected to as-reflowed was propagated through the solder matrix. However, after aging for 1000 h, cracking occurred primarily between intermetallic compound layers.

Gold and aluminum wire bonding to palladium surface finishes

Circuit World ◽  
1999 ◽  
Vol 25 (3) ◽  
pp. 23-27 ◽  
Author(s):  
Chonglun Fan ◽  
Joseph A. Abys ◽  
Alan Blair
Keyword(s):  
Wire Bonding ◽  
Aluminum Wire ◽  
Surface Finishes ◽  
Palladium Surface

ENPLATE NI-423

Alloy Digest ◽  
1986 ◽  
Vol 35 (11) ◽  
Keyword(s):  
Wear Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
High Speed ◽  
Chemical Reduction ◽  
Electronic Devices ◽  
Electroless Nickel ◽  
Heat Treating ◽  
Corrosion And Wear ◽  
Phosphorus Alloy

Abstract ENPLATE NI-423 is a nickel-phosphorus alloy deposited by chemical reduction without electric current. It is deposited by a stable, relatively high-speed functional electroless nickel process that produces a low-stress coating with good ductility and excellent resistance to corrosion. Its many uses include equipment for chemicals and food, aerospace components, molds and electronic devices. This datasheet provides information on composition, physical properties, and hardness. It also includes information on corrosion and wear resistance as well as heat treating, machining, joining, and surface treatment. Filing Code: Ni-343. Producer or source: Enthone Inc..

Case Studies of Brittle Interfacial Failures in Area Array Solder Interconnects

2000 ◽  
Author(s):  
George M. Wenger ◽  
Richard J. Coyle ◽  
Patrick P. Solan ◽  
John K. Dorey ◽  
Courtney V. Dodd ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Case Studies ◽  
Failure Modes ◽  
Electroless Nickel ◽  
Electrical Performance ◽  
Printed Wiring Board ◽  
Solder Interconnects ◽  
Area Array ◽  
Surface Finishes ◽  
Soldering Reaction

Abstract A common pad finish on area array (BGA or CSP) packages and printed wiring board (PWB) substrates is Ni/Au, using either electrolytic or electroless deposition processes. Although both Ni/Au processes provide flat, solderable surface finishes, there are an increasing number of applications of the electroless nickel/immersion gold (ENi/IAu) surface finish in response to requirements for increased density and electrical performance. This increasing usage continues despite mounting evidence that Ni/Au causes or contributes to catastrophic, brittle, interfacial solder joint fractures. These brittle, interfacial fractures occur early in service or can be generated under a variety of laboratory testing conditions including thermal cycling (premature failures), isothermal aging (high temperature storage), and mechanical testing. There are major initiatives by electronics industry consortia as well as research by individual companies to eliminate these fracture phenomena. Despite these efforts, interfacial fractures associated with Ni/Au surface finishes continue to be reported and specific failure mechanisms and root cause of these failures remains under investigation. Failure analysis techniques and methodologies are crucial to advancing the understanding of these phenomena. In this study, the scope of the fracture problem is illustrated using three failure analysis case studies of brittle interfacial fractures in area array solder interconnects. Two distinct failure modes are associated with Ni/Au surface finishes. In both modes, the fracture surfaces appear to be relatively flat with little evidence of plastic deformation. Detailed metallography, scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and an understanding of the metallurgy of the soldering reaction are required to avoid misinterpreting the failure modes.

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