Effect of Ni-P Plating Temperature on Growth of Interfacial Intermetallic Compound in Electroless Nickel Immersion 
Gold/Sn-Ag-Cu Solder Joints

An epoxy Sn–58wt.%Bi solder joint was evaluated by a three-point bending test with electroless nickel immersion gold (ENIG) and electroless nickel electroless palladium immersion gold (ENEPIG) surface finishes aged at 85 °C and 85% relative humidity. Scanning electron microscopy and electron probe microanalysis were carried out to study intermetallic compound variation. The morphology, total thickness, and chemical composition of intermetallic compound in epoxy Sn58Bi solder joints were the same as those of Sn–58wt.%Bi solder joints with each surface finish. The average number of bending-to-failure cycles for the epoxy Sn–58wt.%Bi solder/ENIG joints and epoxy Sn–58wt.%Bi solder/ENEPIG was more than 4000 and 5000, respectively. The average number of bending-to-failure cycles of the epoxy Sn–58wt.%Bi solder joint decreased with increasing age. Three-point bending reliability of epoxy Sn–58wt.%Bi solder joints was higher than that of Sn–58wt.%Bi solder with both surface finishes. Cracking of all solder joints subjected to as-reflowed was propagated through the solder matrix. However, after aging for 1000 h, cracking occurred primarily between intermetallic compound layers.

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Impact of Black Pad and Intermetallic Layers on the Risk for Fractures in Solder Joints to Electroless Nickel/Immersion Gold

The ELFNET Book on Failure Mechanisms, Testing Methods, and Quality Issues of Lead-Free Solder Interconnects ◽

10.1007/978-0-85729-236-0_8 ◽

2011 ◽

pp. 179-195 ◽

Cited By ~ 1

Author(s):

P.-E. Tegehall

Keyword(s):

Solder Joints ◽

Electroless Nickel ◽

Electroless Nickel Immersion Gold ◽

Black Pad ◽

Intermetallic Layers

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Effect of Ni concentration on solderability, microstructure and hardness of SAC0705-xNi solder joints on Cu and graphene-coated Cu substrates

Modern Physics Letters B ◽

10.1142/s0217984918504250 ◽

2019 ◽

Vol 33 (01) ◽

pp. 1850425 ◽

Cited By ~ 1

Author(s):

Hongming Cai ◽

Yang Liu ◽

Shengli Li ◽

Hao Zhang ◽

Fenglian Sun ◽

...

Keyword(s):

Intermetallic Compound ◽

Diffusion Barrier ◽

Graphene Layer ◽

Solder Joints ◽

Cu Substrate ◽

Ni Content ◽

Increasing Trend ◽

Cu Substrates ◽

Interfacial Intermetallic Compound ◽

Positive Effect

In this paper, solderability, microstructure and hardness of SAC0705-xNi solder joints on Cu and graphene-coated Cu (G-Cu) substrates were studied. As Ni content increases in the solder, the solderability improves gradually on both the Cu and G-Cu substrates. The solderability of SAC0705-xNi is better on G-Cu substrate than that on Cu substrate. The increasing Ni content in the solder has a positive effect on the microstructure refinement of both the kinds of substrates. Such effect is more significant on G-Cu substrate than that on Cu substrate. With the increase of Ni content, the thickness of the interfacial intermetallic compound (IMC) shows an increasing trend first and then decreasing trend on the two kinds of substrates. Since the graphene layer works as a diffusion barrier, the IMC on G-Cu is thinner than that on Cu substrate. The addition of Ni leads to the strengthening of the microstructure and thus increases the hardness of the solder bulks.

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