Comparative Reliability Studies and Analysis of Au, Pd-Coated Cu and Pd-Doped Cu Wire in Microelectronics Packaging (original) (raw)
Related papers
PLOS ONE, 2014
This paper compares and discusses the wearout reliability and analysis of Gold (Au), Palladium (Pd) coated Cu and Pd-doped Cu wires used in fineline Ball Grid Array (BGA) package. Intermetallic compound (IMC) thickness measurement has been carried out to estimate the coefficient of diffusion (D o) under various aging conditions of different bonding wires. Wire pull and ball bond shear strengths have been analyzed and we found smaller variation in Pd-doped Cu wire compared to Au and Pd-doped Cu wire. Au bonds were identified to have faster IMC formation, compared to slower IMC growth of Cu. The obtained weibull slope, b of three bonding wires are greater than 1.0 and belong to wearout reliability data point. Pd-doped Cu wire exhibits larger time-to-failure and cycles-to-failure in both wearout reliability tests in Highly Accelerated Temperature and Humidity (HAST) and Temperature Cycling (TC) tests. This proves Pd-doped Cu wire has a greater potential and higher reliability margin compared to Au and Pd-coated Cu wires.
Journal of Electronic Packaging, 2013
Wearout reliability and high temperature storage life (HTSL) activation energy of Au and Pd-coated Cu (PdCu) ball bonds are useful technical information for Cu wire deployment in nanoscale semiconductor device packaging. This paper discusses the influence of wire type on the wearout reliability performance of Au and PdCu wire used in fine pitch BGA package after HTSL stress at various aging temperatures. Failure analysis has been conducted to identify the failure mechanism after HTSL wearout conditions for Au and PdCu ball bonds. Apparent activation energies (Eaa) of both wire types are investigated after HTSL test at 150 °C, 175 °C and 200 °C aging temperatures. Arrhenius plot has been plotted for each ball bond types and the calculated Eaa of PdCu ball bond is 0.85 eV and 1.10 eV for Au ball bond in 110 nm semiconductor device. Obviously Au ball bond is identified with faster IMC formation rate with IMC Kirkendall voiding while PdCu wire exhibits equivalent wearout and or better w...
2013
Wearout reliability and diffusion kinetics of Au and Pd-coated Cu (PdCu) ball bonds are useful technical information for Cu wire deployment in nanoscale semiconductor device packaging. is paper discusses the HAST (with bias) and UHAST (unbiased HAST) wearout reliability performance of Au and PdCu wires used in �ne pitch �GA packages. In-depth failure analysis has been carried out to identify the failure mechanism under various wearout conditions. Intermetallic compound (IMC) diffusion constants and apparent activation energies ( aa ) of both wire types were investigated aer high temperature storage life test (HTSL). Au bonds were identi�ed to have faster IMC formation, compared to slower IMC growth of PdCu. PdCu wire was found to exhibit e�uivalent or better wearout reliability margin compared to conventional Au wire bonds. Failure mechanisms of Au, Cu ball bonds post-HAST and UHAST tests are been proposed, and both Au and PdCu IMC diffusion kinetics and their characteristics are discussed in this paper.
Extended reliability of gold and copper ball bonds in microelectronic packaging
Gold Bulletin, 2013
Wire bonding is the predominant mode of interconnection in microelectronic packaging. Gold wire bonding has been refined again and again to retain control of interconnect technology due to its ease of workability and years of reliability data. Copper (Cu) wire bonding is well known for its advantages such as cost-effectiveness and better electrical conductivity in microelectronic packaging. However, extended reliabilities of Cu wire bonding are still unknown as of now. Extended reliabilities of Au and Pd-coated Cu (Cu) ball bonds are useful technical information for Au and Cu wire deployment in microelectronic packaging. This paper discusses the influence of wire type and mold compound effect on the package reliability and after several component reliability stress tests. Failure analysis has been conducted to identify its associated failure mechanisms after the package conditions for Au and Cu ball bonds. Extended reliabilities of both wire types are investigated after unbiased HAST (UHAST), temperature cycling (TC), and high-temperature storage life test (HTSL) at 150, 175, and 200°C aging temperatures. Weibull plots have been plotted for each reliability stress. Obviously, Au ball bond is found with longer time to failure in unbiased HAST stress compared to Cu ball bonds for both mold compounds. Cu wire exhibits equivalent package and or better reliability margin compared to Au ball bonds in TC and HTSL tests. Failure mechanisms of UHAST and TC have been proposed, and its mean time to failure (t 50 ), characteristic life (t 63.2 , η), and shape parameter (ß) have been discussed in this paper. Feasibility of silver (Ag) wire bonding deployment in microelectronic packaging is discussed at the last section in this paper.
Technical Barriers and Development of Cu Wirebonding in Nanoelectronics Device Packaging
Journal of Nanomaterials, 2012
Bondpad cratering, Cu ball bond interface corrosion, IMD (intermetal dielectric) cracking, and uncontrolled post-wirebond staging are the key technical barriers in Cu wire development. This paper discusses the UHAST (unbiased HAST) reliability performance of Cu wire used in fine-pitch BGA package. In-depth failure analysis has been carried out to identify the failure mechanism under various assembly conditions. Obviously green mold compound, low-halogen substrate, optimized Cu bonding parameters, assembly staging time after wirebonding, and anneal baking after wirebonding are key success factors for Cu wire development in nanoelectronic packaging. Failure mechanisms of Cu ball bonds after UHAST test and CuAl IMC failure characteristics have been proposed and discussed in this paper.
Crystals, 2013
A comparison study on the reliability of gold (Au) and copper (Cu) wire bonding is conducted to determine their corrosion and oxidation behavior in different environmental conditions. The corrosion and oxidation behaviors of Au and Cu wire bonding are determined through soaking in sodium chloride (NaCl) solution and high temperature storage (HTS) at 175 °C, 200 °C and 225 °C. Galvanic corrosion is more intense in Cu wire bonding as compared to Au wire bonding in NaCl solution due to the minimal formation of intermetallics in the former. At all three HTS annealing temperatures, the rate of Cu-Al intermetallic formation is found to be three to five times slower than Au-Al intermetallics. The faster intermetallic growth rate and lower activation energy found in this work for both Au/Al and Cu/Al as compared to literature could be due to the thicker Al pad metallization which removed the rate-determining step in previous studies due to deficit in Al material.
Evolution of Bonding Wires used in Semiconductor Packaging: Perspective over 25 years
The objective of this review is to study the evolution and key findings and critical technical challenges, solutions and future trend of bonding wires used in semiconductor electronics. Evolutions of bonding wires from Au to Cu and till the most recent silver (Ag) wire (perspective over 25 years packaging technology) have been discussed in this paper. The reliability performances of Au wire bonding, technical barriers of Cu wire bonding and corrosion mechanisms of Cu ball bonds are analyzed and covered. We focus on the influence of a variety of factors that have been reported recently, including reliability performance, wear out reliability performance that determine the selection of bonding wires to reach for developing high reliability of bonded devices. In the end of this review, the evolutions and future trends of bonding wires are compared and illustrated, which have marked effect based on the materials properties as well as reliability of wire types.
Reliability challenges of Cu wire deployment in flash memory packaging
Proceedings of Technical Papers - International Microsystems, Packaging, Assembly, and Circuits Technology Conference, IMPACT, 2012
Cu wirebonding become a great interest of industry in recent years due to its cost effectiveness and electrical and mechanical properties. However, several Cu wire bond reliability challenges are the key concerns in Cu wire deployment in semiconductor packaging. These include Cu wire oxidation and CuAl interface corrosion post HAST or UHAST reliability test. Bond reliability at a Cu wire bond under a humid environment is a major concern in replacing Au wires. Conventional bare Cu bonding wires, in general, are more susceptible to moisture corrosion compared to Au wire. This paper discusses the key reliability challenges Cu wire used in flash fineline BGA package. Cu wire IMD cracking induced by excessive ultrasonic bonding force, Cu wire oxidation due to long staging and Cu ball bond corrosion are discussed in this paper. Failure mechanisms and proposals for reliability improvement have been proposed and discussed in this paper.
Evolutions of bonding wires used in semiconductor electronics: perspective over 25 years
2014
The objective of this review is to study the evolution and key findings and critical technical challenges, solutions and future trend of bonding wires used in semiconductor electronics. Evolutions of bonding wires from Au to Cu and till the most recent silver (Ag) wire (perspective over 25 years packaging technology) have been discussed in this paper. The reliability performances of Au wire bonding, technical barriers of Cu wire bonding and corrosion mechanisms of Cu ball bonds are analyzed and covered. We focus on the influence of a variety of factors that have been reported recently, including reliability performance, wear out reliability performance that determine the selection of bonding wires to reach for developing high reliability of bonded devices. In the end of this review, the evolutions and future trends of bonding wires are compared and illustrated, which have marked effect based on the materials properties as well as reliability of wire types.