Comparison of Joint Strength and Fracture Energy of Lead-free Solder Balls in High Speed Ball Shear/Pull Tests and their Correlation with Board Level Drop Test

Song, Fubin; Lee, S. W. Ricky; Newman, Keith; Clark, Stephen L.; Sykes, B.

doi:10.1109/eptc.2007.4469720

Cited by 17 publications

(6 citation statements)

References 14 publications

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“…Extensive reports of ball impact pull tests can be found in the works of Newman [43] and Song et al [50][51][52]. Compared to ball impact shear tests, ball impact pull tests exhibit a lower ductileto-brittle-transition test speed.…”

Section: Review Of Test Methodsmentioning

confidence: 94%

“…Unfortunately, the complexity of the setup limits the test to laboratory use. Ball impact shear tests using a simpler test setup that employs a striker attached with a load cell were reported by Newman [43] of Sun Microsystems, Wong et al [44,45] of IME, Yeh et al [46,47] and Lai et al [48] of ASE, Valota et al [49] of ST Microelectronics, Song et al [50][51][52] of HKUST, and Zhao et al [53] of Philips. The displacement of the striker was measured using a linear variable differential transformer (LVDT).…”

Section: Review Of Test Methodsmentioning

confidence: 94%

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A review of board level solder joints for mobile applications

Wong

Seah

Shim

2008

Microelectronics Reliability

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Section: Review Of Test Methodsmentioning

confidence: 94%

Section: Review Of Test Methodsmentioning

confidence: 94%

A review of board level solder joints for mobile applications

Wong

Seah

Shim

2008

Microelectronics Reliability

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“…Such fast tool displacement reproduces the local velocity of solder joints in BGA package under drop impact test condition. The high simulated test speed also ensures rapid load transfer from the shear tool to the interface region to facilitate brittle fracture at solder/IMC interface, as observed experimentally [7,[13][14][15][16]18]. The solder ball shear push test is simulated at 30 o C.…”

Section: Finite Element Model Of Solder Ball Shear Push Testmentioning

confidence: 98%

“…Solder/IMC interface fracture is another common failure mode in Pb-free solder interconnects, particularly under drop impact loading [13][14][15][16]. In addition to instrumented board drop impact test, high-speed solder ball pull tests and ball shear push test on reflowed solder samples have been devised in an effort to gather reliability data and establish the strength and examine failure modes of the solder joints [17].…”

Section: Introductionmentioning

confidence: 99%

Damage mechanics of solder/IMC interface fracture in Pb-free solder interconnects

Lai

Keat

Tamin

2009

2009 11th Electronics Packaging Technology Conference

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This study addresses the mechanics of the relatively brittle solder/intermetallic (IMC) interface fracture process using damage mechanics concept. The damage state, ϕ of a material point in the solder/IMC interface, is expressed in terms of orthogonal traction components in a quadratic failure criterion of a cohesive zone model. The model is then employed in a finite element analysis of a solder ball shear push test. The simulated test specimen consists of reflowed SAC405 solderon-OSP copper pad and orthotropic FR4 substrate. Unified inelastic strain constitutive model with optimized material parameters describes the strain rate-response of the SAC405 solder. The cohesive zone model parameter values are compiled from published experimental data on SAC405 solder ball pull tests and shear push tests. The predicted shear tool force-displacement curve compared well with published experimental data. The normal-to-shear traction ratio at the onset of interface fracture is 1.59 indicating significant induced bending effect due to shear tool clearance. Rapid interface crack propagation is predicted following the initiation of crack with the average crack speed up to 24.6 times the applied shear tool speed at 3000 mm/sec. The progressive boundary between damaged (ϕ<1.0) and fractured (ϕ=1.0) interface is interpreted as the interface crack front. The high stress concentration along the edge of the solder/IMC interface facilitates local crack initiation and dictates the shape of the dynamic crack front. IntroductionLead-free solder interconnects have become an integral part of microelectronics chips development due to legislative requirements on environment-friendly devices. The use of SnAg based solders raised the reflow temperature and the upper limit of the reliability temperature cycles. In addition, the use of different surface finishes of the substrate leads to different ball limiting metallurgy in the solder interconnection particularly at the solder/intermetallics (IMC) interface. The mechanics of such solder interconnections under reliability load cycles and device operating conditions dictates the reliability of the assembly.

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“…Due to the wide use of portable electronics and the implementation of lead-free solders, the brittle failure mechanism of solder joints under the dynamic loading condition has gained more and more attentions [1][2][3][4][5][6][7][8]. Previous studies indicated that excessive growth of IMCs may promote the brittle failure through weakening the solder joint strength, and hence affect the long term solder joint reliability [7].…”

Section: Introductionmentioning

confidence: 99%

Effect of interfacial strength between Cu<inf>6</inf>Sn<inf>5</inf> and Cu<inf>3</inf>Sn intermetallics on the brittle fracture failure of lead-free solder joints with OSP pad finish

Yang

Song

Lee

2011

2011 IEEE 61st Electronic Components and Technology Conference (ECTC)

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The brittle failure mechanism of solder joints has gained more and more attention due to the introduction of lead-free solders and also the extensive use of different kinds of portable electronic products. The excessive growth of the IMC is blamed to increase the propensity of the brittle failure. Typically the thickness of the IMC layer is used to indicate the risk of failure of solder joints. Cu 6 Sn 5 and Cu 3 Sn are the most common IMCs found in Sn-Ag-Cu (SAC) lead-free solder joints with OSP pad finish. Previous studies revealed that the brittle failure mostly occurred in the IMC region. However, the respective role of Cu 6 Sn 5 and Cu 3 Sn in the solder joint brittle failure still remains unclear.In the present study, different amounts of Nickel (Ni) were doped in the Sn-Cu based solder. Its effects on the growth rate of (Cu, Ni) 6 Sn 5 /Cu 6 Sn 5 and Cu 3 Sn were characterized at first. Subsequently, the results of characterization were utilized to produce different growth rates of (Cu, Ni) 6 Sn 5 and Cu 3 Sn under thermal aging. The thicknesses of (Cu, Ni) 6 Sn 5 /Cu 6 Sn 5 and Cu 3 Sn after different aging hours were measured using SEM (with EDX and BSE). High speed ball pull/shear tests were performed. The correlation between IMC strength and IMC layer thicknesses was established. An investigation on the effect of Ni on the micro-hardness of solder is also included in this study.

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Comparison of Joint Strength and Fracture Energy of Lead-free Solder Balls in High Speed Ball Shear/Pull Tests and their Correlation with Board Level Drop Test

Cited by 17 publications

References 14 publications

A review of board level solder joints for mobile applications

A review of board level solder joints for mobile applications

Damage mechanics of solder/IMC interface fracture in Pb-free solder interconnects

Effect of interfacial strength between Cu<inf>6</inf>Sn<inf>5</inf> and Cu<inf>3</inf>Sn intermetallics on the brittle fracture failure of lead-free solder joints with OSP pad finish

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