Assessment of 20 Micrometer Diameter Wires for Wire Bond Interconnect Technology

2007 ◽  
Author(s):  
S. Saiyed ◽  
S. A. Kudtarkar ◽  
R. Murcko ◽  
K. Srihari
Keyword(s):  
High Temperature ◽  
Stress Test ◽  
Small Diameter ◽  
Mechanical Tests ◽  
Stress Tests ◽  
Bonding Wire ◽  
Chip Area ◽  
Wire Bond ◽  
Ball Bonds ◽  
The Wire

In the domain of wire bonding technology, the size and pitch of bond pads and ball bonds are shrinking to accommodate the demand for higher I/Os and increased functionality per chip area. This trend serves as a catalyst for bonding wire manufacturers to continuously develop lower diameter bonding wires. One mil (25 μm) diameter bonding wire, used widely in this interconnection technique, is now being replaced by 0.8 mil (20 μm) diameter bonding wire. In keeping with the need for higher operating speeds and higher temperatures for today’s ICs, the reliability of ball bonds formed by small diameter wires is of concern and requires investigation. This study explores the effects of 0.8 mil (20 μm) diameter bonding wire on the wire bond ball joint reliability and compares these effects with 1.0 mil (25 μm) diameter bonding wire. The reliability of the ball bonds was assessed using mechanical tests (wire pull and ball shear) for units subjected to stress tests such as the unbiased highly accelerated stress test and high temperature storage tests. The results of this investigation reveal that both the wire diameters are able to sustain their integrity after moisture testing. But, the bond strength degrades after high temperature tests due to the Kirkendall voiding mechanism occurring between gold wire and the aluminum bond pad.

To Study the High Temperature Effects on Ball Bonds Using Low K Material in Wire Bond Devices

2007 ◽  
Author(s):  
S. A. Kudtarkar ◽  
R. Murcko ◽  
K. Srihari ◽  
S. Saiyed
Keyword(s):  
High Temperature ◽  
Mechanical Stability ◽  
Semiconductor Industry ◽  
Gold Wire ◽  
Wire Bonding ◽  
Mechanical Stresses ◽  
Wire Bond ◽  
Ball Bonds ◽  
Bond Pads ◽  
Low K

Wire bonding is widely used as one of the main interconnect alternatives. This technique applies significant mechanical stresses on the bond pads along with heat and ultrasonic energy to form a bond. An interconnection of copper plus low k material has been a focus of the semiconductor industry with the goal of reducing interconnection delays. The material is below the wire bond pads and complicates the mechanical stability of the device during wire bonding. The low k materials that are suggested are very sensitive to these mechanical stresses. This generates a significant reliability concern for the underlying metal structures. In addition, the integrity of the bond formed may be negatively impacted from a reliability perspective because of the softer material properties of the dielectric. This research explores the ball bond integrity for die with SiO2 and low k dielectric underlying material respectively, using 0.8 mil thick (20 microns) gold wire. Accelerated tests, such as high temperature storage at 150°C and 175°C, were conducted to assess the reliability of these bonds. The results of this investigation reveal that the ball bond’s strength degrades after high temperature tests due to the occurrence of Kirkendall voids between the gold wire and the aluminum bond pad. The degradation recorded was more severe for regular die than its low k counterpart.

Evaluation of Secondary Wire Bond Integrity on Ag Plated and Ni/Pd Based Lead Frame Plating Finishes

2009 ◽  
Author(s):  
G. Srinivasan ◽  
R. Murcko ◽  
K. Srihari
Keyword(s):  
High Temperature ◽  
Failure Analysis ◽  
Wire Bonding ◽  
Strength Test ◽  
Lead Frame ◽  
Wire Bond ◽  
Pull Strength ◽  
High Temperature Storage ◽  
The Wire ◽  
Temperature Storage

As the legislatures demand the use of lead (Pb) free plating finishes in lead frame manufacturing, different plating finishes are being offered by the lead frame makers. Lead frames are most often designed with two different Pb free plating finishes, primarily tin and nickel/palladium (Ni/Pd) based. The tin post mold plated lead frames use silver selective plating on the lead fingers for secondary wire bonding whereas the pre-plated Ni/Pd based lead frames use the same Ni/Pd based finish throughout. Enhanced versions of Ni/Pd based plating finishes such as nickel/palladium/gold (Ni/Pd/Au), nickel/palladium/gold-palladium (Ni/Pd/Au-Pd) and nickel/palladium/gold-silver (Ni/Pd/Au – Ag) are now available to further improve the wirebondability, solderability and reliability of the package. The development of a new lead frame finish involves a wide variety of concerns which must be addressed and thus mandates further evaluation of these new structures. Using the common Pb free lead frame plating finish of selectively plated silver (Ag) as the basis, a comparative approach was used to evaluate the secondary wire bond integrity of a 25 micron (1 mil) thick gold wire on Ni/Pd based lead frame plating finishes. The integrity of the secondary wire bonds for different plating finishes was investigated at various assembly thermal exposure stages using the wire pull strength test as the arbiter. Reliability tests, such as High Temperature Storage (HTS) and Unbiased Highly Accelerated Stress Test (UBHAST), were also conducted. Finally, failure analysis was conducted with the help of metallographic cross sectioning, SEM/EDX (Scanning Electron Microscope/Energy Dispersive X-ray) analysis and statistical analysis of the wire pull strength test results. Before wire bonding the lead frames, the plating surface was investigated for its surface integrity with the help of plating quality tests, such as: (i) adhesive tape test, (ii) bend test, (iii) heating test and the (iv) scribing test. Also, since wire pull is a destructive test, a statistical method called a nested gauge R&R study was used to estimate the repeatability and reproducibility of the measurement system. Failure analysis showed that there were silver and copper migrations over the Ag plated lead frame when exposed to a high temperature storage test at 175°C for 1000 hrs, but this did not affect the bond integrity. However, the Ni/Pd based lead frames did not show any metal migration since nickel acts as a barrier against the base metal diffusion.

High bond reliability of newly developed silver alloy bonding wire

2019 ◽  
Vol 2019 (1) ◽  
pp. 000524-000529
Author(s):  
Noritoshi Araki ◽  
Motoki Eto ◽  
Takumi Ohkabe ◽  
Teruo Haibara ◽  
Takashi Yamada ◽  
...  
Keyword(s):  
High Temperature ◽  
Stress Test ◽  
Cost Effective ◽  
Automotive Electronics ◽  
Bonding Wire ◽  
Suitable Alternative ◽  
Bonding Property ◽  
Bond Interface ◽  
Accelerated Stress Test

Abstract In this paper, a new type of silver (Ag) alloy bonding wire is introduced, and its bonding property and long term reliability are demonstrated. The new Ag wire, called GX2s, is developed as a cost-effective alternative to gold (Au) wire targeting at automotive electronics. The wire material is doped with added element, and its electrical resistivity is much lower than the conventional palladium (Pd) doped Ag wire. Highly accelerated stress test (HAST) and high temperature storage life (HTSL) test were carried out along with other bonding evaluations. The results show that GX2s has good bonding property and excellent long term bond reliability. Microstructural analyses of bond interface after the reliability tests were also conducted to investigate its improving mechanism. GX2s is a suitable alternative to Au wire for many applications including high temperature automotive devices.

Effects of ball bond diameter on wire bond reliability for automotive application

2016 ◽  
Vol 33 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Hui Yuen Peng ◽  
Mutharasu Devarajan ◽  
Teik Toon Lee ◽  
David Lacey
Keyword(s):  
Isothermal Aging ◽  
Production Costs ◽  
Automotive Application ◽  
Comsol Multiphysics ◽  
Ball Bond ◽  
Content Type ◽  
Wire Bond ◽  
Wire Bonds ◽  
Ball Bonds ◽  
The Wire

Purpose – The purpose of this paper is to investigate the reliability of wire bonds with three varying ball bond diameters, which are ball bonded with three different sizes of gold wires in light-emitting diode (LED) package under high-temperature environment. In automotive applications, “lifted ball bond” issue is a potential critical point for LED device reliability, as the wire bonds are usually stressed under high operating temperature during their lifetime. Moreover, the reliability of wire bonds in recent LED production has fallen under scrutiny due to the practice of reducing wire diameters to cut down production costs. Design/methodology/approach – Three gold wires with sizes of 2, 1.5 and 1 mm were ball bonded on the LED chip bond pad via thermosonic wire bonding method to produce three different ball bond diameters, that is, 140, 120 and 100 μm, respectively. The reliability of these wire bond samples was then studied by performing isothermal aging at 200°C for the time interval of 30, 100 and 500 hours. To validate hypotheses based on the experimental data, COMSOL Multiphysics simulation was also applied to study the thermal stress distribution of wire bond under an elevated temperature. Findings – Experimental results show that the interfacial adhesion of wire bond degrades significantly after aging at 200°C for 500 hours, and the rate of interfacial degradation was found to be more rapid in the wire bond with smaller ball bond diameter. Experimental results also show that ball bonds randomly elongate along an axis and deforms into elliptical shapes after isothermal aging, and ball bonds with smaller diameters develop more obvious elongations. This observation has not been reported in any previous studies. Simulation results show that higher thermal stress is induced in the wire bond with the decrease of ball bond diameter. Practical implications – The reliability study of this paper provides measurements and explanation on the effects of wire diameter downsizing in wire bonds for automotive application. This is applicable as a reliability reference for industries who intend to reduce their production costs. Other than that, the analysis method of thermal stresses using COMSOL Multiphysics simulations can be extended by other COMSOL Multiphysics users in the future. Originality/value – To resolve “lifted ball bond” issue, optimization of the bond pad surface quality and the wire bond parameter has been studied and reported in many studies, but the influence of ball bond diameter on wire bond reliability is rarely focused. Moreover, the observation of ball bonds randomly elongate and deform more into elliptical shape, and ball bond with smaller diameter has the highest elongation after isothermal aging also still has not been reported in any previous studies.

Characterization of CMOS Structures (0.6 µm process) Submitted to HBM and COM ESD Stress Tests

1997 ◽  
Author(s):  
G. Meneghesso ◽  
E. Zanoni ◽  
P. Colombo ◽  
M. Brambilla ◽  
R. Annunziata ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrostatic Discharge ◽  
Stress Test ◽  
Complete Characterization ◽  
Stress Tests ◽  
Test Procedures ◽  
Emission Microscopy ◽  
Fast Rise ◽  
Scanning Electron

Abstract In this work, we present new results concerning electrostatic discharge (ESD) robustness of 0.6 μm CMOS structures. Devices have been tested according to both HBM and socketed CDM (sCDM) ESD test procedures. Test structures have been submitted to a complete characterization consisting in: 1) measurement of the tum-on time of the protection structures submitted to pulses with very fast rise times; 2) ESD stress test with the HBM and sCDM models; 3) failure analysis based on emission microscopy (EMMI) and Scanning Electron Microscopy (SEM).

scholarly journals XIX.—Magnetization and Resistance of Nickel Wire at High Temperatures. Part II.

1907 ◽  
Vol 45 (3) ◽  
pp. 547-554
Author(s):  
C. G. Knott
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Electrical Resistance ◽  
British Association ◽  
Nickel Wire ◽  
Present Communication ◽  
Association Meeting ◽  
The Subject ◽  
The Wire

The experiments which form the subject of the present communication were carried out two years ago, and supplement results already published. A brief note of some of the results was read before the Society in June 1904, and was also read before the British Association Meeting at Cambridge in August of the same year.The previous paper discussed the effect of high temperature on the relation between electrical resistance and magnetization when the wire was magnetized longitudinally, that is, in the direction in which the resistance was measured.The present results have to do with the effect of high temperature on the relation between resistance and magnetization when the magnetization was transverse to the direction along which the resistance was measured.

High temperature storage reliability investigation of the Al–Cu wire bond interface

2012 ◽  
Vol 52 (9-10) ◽  
pp. 1966-1970 ◽  
Author(s):  
R. Pelzer ◽  
M. Nelhiebel ◽  
R. Zink ◽  
S. Wöhlert ◽  
A. Lassnig ◽  
...  
Keyword(s):  
High Temperature ◽  
Wire Bond ◽  
High Temperature Storage ◽  
Bond Interface ◽  
Temperature Storage

The Microstructure and Mechanical Properties of Ni-Based Superalloy after Service Exposure in Gas Turbine

2010 ◽  
Vol 654-656 ◽  
pp. 2523-2526 ◽  
Author(s):  
Keun Bong Yoo ◽  
Han Sang Lee
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Mechanical Tests ◽  
Time Dependent ◽  
Second Stage ◽  
Degradation Analysis ◽  
Check Points ◽  
Tcp Phase ◽  
Service Exposure ◽  
High Temperature Tensile

Many investigations about superalloys and coatings have been done in the laboratory, but evaluating the degradation condition of hot section components during service is still important not only for repair and reuse but also for outage prevention. Time dependent degradation for second stage blades of gas turbine was investigated. The degradation analysis for used blades was divided into microstructure changes by position of the blade and mechanical tests of high temperature tensile test. In the microstructure analysis, the rafting and coarsening of γ', MC decomposition and TCP phase formation occurred and progressed with increasing service time, and especially the leading and trailing edge of top layer should be a check points for used blade. High temperature tensile results of 25,000 and 52,000 hrs used blades were also compared with serviced time and position in each blade.

scholarly journals FCCSP IMC growth under reliability stress follows automotive criteria

2019 ◽  
Vol 3 (1) ◽  
pp. 70-83
Author(s):  
Wei Wei Liu ◽  
Berdy Weng ◽  
Scott Chen
Keyword(s):  
High Temperature ◽  
Flip Chip ◽  
Stress Test ◽  
Temperature Cycling ◽  
Content Type ◽  
Initial Stage ◽  
High Temperature Storage ◽  
Temperature Cycling Test ◽  
Temperature Storage

Purpose The Kirkendall void had been a well-known issue for long-term reliability of semiconductor interconnects; while even the KVs exist at the interfaces of Cu and Sn, it may still be able to pass the condition of unbias long-term reliability testing, especially for 2,000 cycles of temperature cycling test and 2,000 h of high temperature storage. A large number of KVs were observed after 200 cycles of temperature cycling test at the intermetallic Cu3Sn layer which locate between the intermetallic Cu6Sn5 and Cu layers. These kinds of voids will grow proportional with the aging time at the initial stage. This paper aims to compare various IMC thickness as a function of stress test, the Cu3Sn and Cu6Sn5 do affected seriously by heat, but Ni3Sn4 is not affected by heat or moisture. Design/methodology/approach The package is the design in the flip chip-chip scale package with bumping process and assembly. The package was put in reliability stress test that followed AEC-Q100 automotive criteria and recorded the IMC growing morphology. Findings The Cu6Sn5 intermetallic compound is the most sensitive to continuous heat which grows from 3 to 10 µm at high temperature storage 2,000 h testing, and the second is Cu3Sn IMC. Cu6Sn5 IMC will convert to Cu3Sn IMC at initial stage, and then Kirkendall void will be found at the interface of Cu and Cu3Sn IMC, which has quality concerning issue if the void’s density grows up. The first phase to form and grow into observable thickness for Ni and lead-free interface is Ni3Sn4 IMC, and the thickness has little relationship to the environmental stress, as no IMC thickness variation between TCT, uHAST and HTSL stress test. The more the Sn exists, the thicker Ni3Sn4 IMC will be derived from this experimental finding compare the Cu/Ni/SnAg cell and Ni/SnAg cell. Research limitations/implications The research found that FCCSP can pass automotive criteria that follow AEC-Q100, which give the confidence for upgrading the package type with higher efficiency and complexities of the pin design. Practical implications This result will impact to the future automotive package, how to choose the best package methodology and what is the way to do the package. The authors can understand the tolerance for the kind of flip chip package, and the bump structure is then applied for high-end technology. Originality/value The overall three kinds of bump structures, Cu/Ni/SnAg, Cu/SnAg and Ni/SnAg, were taken into consideration, and the IMC growing morphology had been recorded. Also, the IMC had changed during the environmental stress, and KV formation was reserved.

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