Effect Of Contact Pad’s Roughness And Ni–P Plating Thickness On Leadless Packages’ Shear Strength Variation

Lau, Kok Tee and Munawar, Rose Farahiyan and Arif@Harip, Afraha Baiti and Ong, C. G. (2020) Effect Of Contact Pad’s Roughness And Ni–P Plating Thickness On Leadless Packages’ Shear Strength Variation. Transactions on Electrical and Electronic Materials, 21. pp. 1-9. ISSN 1229-7607

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Studies on shear strength of thin small leadless packages (TSLP) focused predominantly on solder and refow factors. Contact pad’s surface roughness (Ra) and Ni–P thickness factors, though rather important, have not been reported widely. Thus, the current study investigates the efect of TSLP’s contact pad, in terms of Ra and Ni–P’s thickness, on shear strength variation of the TSLP after being soldered on PCB. The Ra was controlled by using diferent Cu alloy leadframes, etchant’s pH and etching conveyor speeds. A shear test was conducted on the soldered TSLP using the Dage Series-4000-Bond-Tester as per Infneon’s specifcations. The shear test data was supported by failure mode results in the form of scanning electron microscopy images and energy-dispersive X-ray analysis. The present work revealed that TSLP with high contact pad’s Ra exhibited a wide shear strength variation. In addition, thicker Ni–P signifcantly enlarged the shear strength variation of TSLP when the etched surface of the contact pad’s Ra is low. After solder refow, the contact pad’s high Ra and Ni–P thickness triggered the formation of more heterogeneous pores in the solder region of the solder joint between TSLP and PCB. This resulted in shear failure at the porous solder region and heterogeneous shear strength of the soldered TSLP.

Item Type: Article
Uncontrolled Keywords: Alkaline Etching, EN Plating, Electroless Nickel Plating, Shear Strength, Contact Pad Roughness
Divisions: Faculty of Mechanical and Manufacturing Engineering Technology
Depositing User: Norfaradilla Idayu Ab. Ghafar
Date Deposited: 09 Dec 2020 12:27
Last Modified: 09 Dec 2020 12:27
URI: http://eprints.utem.edu.my/id/eprint/24642
Statistic Details: View Download Statistic

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