Wirebonding at higher ultrasonic frequencies: reliability and process implications

Charles, Harry K.; Mach, K. J.; Lehtonen, S. J.; Francomacaro, A. S.; Deboy, J. S.; Edwards, R. Lawrence

doi:10.1016/s0026-2714(02)00118-x

Cited by 40 publications

(22 citation statements)

References 4 publications

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“…However, no significant improvement in wire bondability was found by using 100 kHz compared to 60 kHz on the Al + 1% silicon metallization, as reported by Charles et al [2]. Charles et al [2] also concluded that the 60 kHz system produced more consistent bonds than the 100 kHz system in the transition from rigid to soft substrates with gold metallization. In the authors' opinion, existing knowl edge on the effect of ultrasonic frequency in wire bondability and reliability is still very limited and more studies are needed.…”

Section: Introductionmentioning

confidence: 87%

“…Various other test methods were presented by Schafft [9]. In two recent peerreviewed journal articles on high frequency wire bonding studies, the wire pull test and the widths of deformed wire were used to evaluate the bondability of wedge bonding [6], and the ball shear test was used for ball bonding [2]. In this study, multiple response variables were used to determine if a bond was optimized.…”

Section: Bonding Process Optimizationmentioning

confidence: 99%

“…Wire bonding typically uses 60 kHz ultrasonic frequency. The original rea son for choosing 60 kHz in the 1960s was that this frequency resulted in transducers and tools that were appropriate to dimensions for microelectronic assemblies and stability during the bonding load [1,2]. Beginning in the early 1990s, researchers started to investi gate higher frequencies to improve wire bondability.…”

Section: Introductionmentioning

confidence: 99%

“…Several studies have shown that increasing ultrasonic fre quency from 60 kHz to over 90 kHz can reduce bonding time [2,3,5], reduce bonding temperature [3,4], reduce bond defor mation [4,6], increase bond strength [6], and improve wire bonding to pads over soft polymers such as Teflon or unrein forced polyimide [7]. However, no significant improvement in wire bondability was found by using 100 kHz compared to 60 kHz on the Al + 1% silicon metallization, as reported by Charles et al [2].…”

Section: Introductionmentioning

confidence: 99%

“…The objectives of this study are: (1) to evaluate the bondability of fine pitch gold wire bonding on organic substrates at 120 kHz ultrasonic frequency, (2) to compare the reliability of the diffusive bonds (fine pitch Au bonds on organic substrates with Au metallization) made at 120 kHz and those made at 60 kHz.…”

Section: Introductionmentioning

confidence: 99%

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The Effect of Ultrasonic Frequency on Gold Wire Bondability and Reliability

Pan¹,

Le²,

Pham³

2009

Journal of Microelectronics and Electronic Packaging

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Abstract�This paper presents a systematic study on the effect of 120 KHz ultrasonic frequency on the bondability and reliabili ty of fine pitch gold wire bonding to pads over an organic sub strate with gold metallizations. The study was carried out on a thermosonic ball bonder that is allowed to easily switch between ultrasonic frequencies of 60 KHz and 120 KHz by changing the ultrasonic transducer and the ultrasonic generator. Bonding pa rameters were optimized through the design of experimental methodology for four different cases: 25.4 mm wire at 60 kHz, 25.4 mm wire at 120 kHz, 17.8 mm wire at 60 kHz, and 17.8 mm wire at 120 kHz. The integrity of wire bonds was evaluated by six response variables. The optimized bonding process was selected according to the multiattribute utility theory. With the optimized bonding parameters developed on one metallization for each of the four cases, 8,100 bonds were made on five different metalliza tions. The samples were then divided into three groups. The first group was subjected to humidity at 85 � C/85% RH for up to 1,000 h. The second group was subjected to thermal aging at 125 � C for up to 1,000 h. The third group was subjected to tem perature cycling from �55 � C to +125 � C with 1 h per cycle for up to 1,000 cycles. The bond integrity was evaluated through the wire pull and the ball shear tests immediately after bonding, and after each 150, 300, 500, and 1,000 h time interval in the reliabili ty tests. Results show that 120 kHz frequency requires less ultra sonic power than 60 kHz when all other parameters are equal. The results also indicate that bonding at 120 kHz frequency is less sensitive to different metallizations than bonding at 60 kHz. All three reliability tests do not negatively affect the bond integrity of Au wire bonds on a variety of Au metallizations for both frequen cies. Furthermore, as the reliability test time increases, both pull and shear strengths of Au wire bonds on Au pads increase.

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Section: Introductionmentioning

confidence: 87%

Section: Bonding Process Optimizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The Effect of Ultrasonic Frequency on Gold Wire Bondability and Reliability

Pan¹,

Le²,

Pham³

2009

Journal of Microelectronics and Electronic Packaging

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High Performance Top‐Emitting Organic Light‐Emitting Diodes for Super Video Graphics Array Monochromatic Microdisplays Application

Zhang

Yue

et al. 2015

Chin. J. Chem.

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We have demonstrated a high performance top-emitting organic light-emitting diode (TEOLED) achieving a brightness of 1000 cd/m 2 at a low voltage of 3.4 V, a power efficiency of 55.2 lm/W at a brightness of 611 cd/m 2 , and a low efficiency roll-off 5.1% calculated from the maximum efficiency value to that of 5000 cd/m 2 . Such improved properties are controlled by electron injection from 7-diphenyl-1,10-phenanthroline (BPhen) into and transport by the 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (TmPPPyTz) layer along with hole injection from 4,4',4''-tris(N-carbazolyl)diphenylamine (TcTa) directly into the fac-tris(2-phenylpyridine)iridium [Ir(ppy) 3 ] highest occupied molecular level (HOMO), leading to direct carrier recombination and excitons formation on the phosphor dopants. Eventually we integrated our high performance TEOLEDs on complementary metal oxide semiconductor (CMOS) substrates to realize super video graphics array (SVGA) OLED microdisplays.

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The Wirebonded Interconnect: A Mainstay for Electronics

Charles

Micro- And Opto-Electronic Materials and Structures: Physics, Mechanics, Design, Reliability, Packaging

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Wirebonding at higher ultrasonic frequencies: reliability and process implications

Cited by 40 publications

References 4 publications

The Effect of Ultrasonic Frequency on Gold Wire Bondability and Reliability

The Effect of Ultrasonic Frequency on Gold Wire Bondability and Reliability

High Performance Top‐Emitting Organic Light‐Emitting Diodes for Super Video Graphics Array Monochromatic Microdisplays Application

The Wirebonded Interconnect: A Mainstay for Electronics

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