• Borgesen, Peter
• Cotts, Eric
• Dimitrov, Nikolay
• Yin, Liang
• Bliznakov, Stoyan
• Wafula, Fred
• Liu, Yihua

Abstract

<jats:p>The lifetime of solder joints with electrodeposited Cu has been an issue to date as many electronic devices have shown a high drop impact failure as a result of a sporadic void formation in the intermetallic compound (IMC).At present, this problem aggravates with the introduction of Pb-free solders. It was recently found that incorporated impurities promote the voiding propensity of Cu/solder joints.The aim of this work is to quantitatively study the role of key Cu plating parameters in the impurity incorporation process. Technically emphasized herein is the plating temperature.Combining results of this study and pre-existing data, a correlation between plating rate, temperature, overpotential, and voiding propensity of accordingly deposited Cu layers is established.Ranges of overpotentials where either "void prone" or "void-free" Cu could be deposited are clearly identified in two separate acidic Cu plating solutions containing different additive combinations. The proposed analysis enables the prediction and control of the voiding propensity of solder joints with electrodeposited Cu layers.</jats:p>

Topics

• impedance spectroscopy
• compound
• copper
• void
• intermetallic