Pb-free surface-finishing on electronic components’ terminals for Pb-free soldering assembly

Tanaka, Hitoshi; Tanimoto, Morimasa; Matsuda, Akihisa; Uno, Takeo; Kurihara, Masaaki; Shoji, Shuichi

doi:10.1007/s11664-999-0160-5

Cited by 13 publications

(5 citation statements)

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“…Good solderability will benefit the formation of high-quality solder joints between the solder and the base material. 1 Each of these finishes has certain advantages and disadvantages. [4][5][6][7][8] The OSP finish is an organic treatment applied over clean copper pads, which protects copper from being corroded or oxidized.…”

Section: Lead-free Surface Finishesmentioning

confidence: 99%

An Assessment of Immersion Silver Surface Finish for Lead-Free Electronics

Wang

Choubey

Azarian

et al. 2009

Journal of Elec Materi

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The worldwide transition to lead-free electronics has increased the usage of several lead-free pad finishes for electronic assembly manufacturers, including immersion silver, immersion tin, electroless nickel-immersion gold, and organic solderability preservatives. This study assesses and compares immersion silver as a circuit board finish in terms of its ease of use, wettability, solderability, shelf life, appearance, solder joint strength, intermetallic and void formation, reliability, and costs.

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Section: Lead-free Surface Finishesmentioning

confidence: 99%

An Assessment of Immersion Silver Surface Finish for Lead-Free Electronics

Wang

Choubey

Azarian

et al. 2009

Journal of Elec Materi

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“…With rising emphasis of ''lead-free'' materials, Pb-Sn solder itself has become the primary target for replacement. Hence, electroplating of alternative binary alloys, such as Sn-Ag, [5][6][7][8][9][10][11] Sn-Bi, 12,13 Sn-Cu, 14,15 as well as the ternary system of Sn-Ag-Cu, [16][17] has been aggressively pursued.…”

Section: Introductionmentioning

confidence: 99%

Effect of Polyethylene Glycol Additives on Pulse Electroplating of SnAg Solder

Chen

et al. 2007

Journal of Elec Materi

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Eutectic Sn-3.5wt.%Ag alloy is one of the most promising lead-free solders in low temperature processes for wafer bumping. Near eutectic composition of deposited alloy films could be readily acquired by pulse electroplating with a proper combination of active ingredients including K 4 P 2 O 7 , KI, Sn 2 P 2 O 7 , and AgI, as well as polyethylene glycol (PEG), with molecular weights of 200, 600, 2,000, and 4,000, as an inhibitive agent. Pulse electroplating was carried out with current in alternating polarity to conduct electroplating and electropolishing sequentially. As a result, alloy films with grains of less than 1 lm and uniform surface morphology can be obtained. The addition of PEG was necessary for the stabilization of the plating baths to promote a wider process window for the desirable eutectic composition. Electrochemical characterization established that PEG with molecular weight of 4,000 exhibited the strongest inhibition behavior. In contrast, PEG with molecular weight of 200 demonstrated the least interference. Energy dispersive X-ray and differential scanning calorimeter data confirmed the formation of eutectic alloy as a function of deposition current density. X-ray diffraction results indicated that a biphasic structures of b-Sn and e-Ag 3 Sn was present in the as-deposited film.

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“…Such absorptions strongly affect the current-potential curves of the Ag, Cu, and Sn depositions. Figures 9,10,and 11 show the effects of thiourea and POELE on Cu, Ag, and Sn depositions, respectively. In the case of Cu deposition ͑Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The plating of some Pb-free alloys such as Sn-Ag, [1][2][3][4][5][6][7][8] Sn-Bi, 9,10 Sn-Zn, 11 and Sn-Cu 12,13 has already been studied, and the use of these alloys offers both advantages and disadvantages. Sn-Ag is the most suitable Pb-free alloy because of its similarity to Sn-Pb alloy, but it is expensive.…”

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confidence: 99%

Effects of Thiourea and Polyoxyethylene Lauryl Ether on Electrodeposition of Sn-Ag-Cu Alloy as a Pb-Free Solder

Fukuda

Imayoshi

Matsumoto

2002

J. Electrochem. Soc.

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The electrodeposition of the eutectic Sn-Ag-Cu alloy ͑Ag: 3.5 wt %, Cu: 0.75 wt %͒ as a Pb-free solder in an H 2 SO 4 plating bath containing thiourea and polyoxyethylene lauryl ether ͑POELE͒ as additives was examined. The addition of thiourea was necessary for the stabilization of the plating bath containing all metal cations Ag ϩ , Cu 2ϩ , and Sn 2ϩ . Both POELE and thiourea produced alloy films with a smooth surface and a homogeneous distribution. Thiourea adsorbed on Ag, Cu, and Sn and suppressed the subsequent codeposition, while POELE adsorbed only on Sn, leading to the suppression of the subsequent Sn deposition. These effects resulted in the codeposition of the Sn-Ag-Cu alloy with a eutectic composition and smooth surface. The melting point of the electrodeposited Sn-Ag-Cu alloy was 216°C, which is consistent with the phase diagram of Sn-Ag-Cu alloy and satisfies the industrial temperature requirements for Pb-free solders.

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Pb-free surface-finishing on electronic components’ terminals for Pb-free soldering assembly

Cited by 13 publications

References 0 publications

An Assessment of Immersion Silver Surface Finish for Lead-Free Electronics

An Assessment of Immersion Silver Surface Finish for Lead-Free Electronics

Effect of Polyethylene Glycol Additives on Pulse Electroplating of SnAg Solder

Effects of Thiourea and Polyoxyethylene Lauryl Ether on Electrodeposition of Sn-Ag-Cu Alloy as a Pb-Free Solder

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