The Black Pad with Graphite Impregnation for CMP

2019 ◽  
Vol 27 (1) ◽  
pp. 581-586 ◽  
Author(s):  
James C. Sung ◽  
Ming-Yi Tsai ◽  
Michael Sung
Keyword(s):  
Black Pad

Identification and prevention of “Black Pad” in Sn/Pb soldering

Circuit World ◽  
2011 ◽  
Vol 37 (3) ◽  
pp. 10-15 ◽  
Author(s):  
Kong Hui Lee
Keyword(s):  
Black Pad

A Study on the Mechanism of Black Pad Formation during Electroless Nickel Immersion Gold process

2010 ◽  
Vol 2010 (1) ◽  
pp. 000306-000313
Author(s):  
J. H. Kim ◽  
K. H. Kim ◽  
Jin Yu
Keyword(s):  
Galvanic Corrosion ◽  
Measurement Techniques ◽  
Electroless Nickel ◽  
Gold Cyanide ◽  
Potential Measurement ◽  
Black Pad ◽  
P Content ◽  
Submicron Scale ◽  
Afm Analysis ◽  
First Time

The “Black Pad” phenomenon referring to blackening of electrolessly plated nickel-phosphorous (Ni(P)) films after the immersion gold (IG) process was reproduced using pure chemicals for the first time. Chemical composition of the electrolyte most suitable for the black pad reproduction was proposed, and it was found that submicron scale nodular variation of the P content of the Ni(P) film induced potential differences large enough to drive galvanic corrosion when exposed to the electrolyte; gold cyanide solution in this case. Instead of conventional potential measurement techniques, corrosion couple experiments using Ni(P) films with different P content were performed to substantiate preferential corrosion, which occurred at the lower P side with the propensity of forming black pad getting more severe with the P content difference (ΔP) between films. Subsequent AFM analysis showed that variations of nodular shapes and curvatures among nodules led to submicron scale variations of the P content in the film, which could promote galvanic corrosion.

Is “black pad” still an issue for ENIG?

Circuit World ◽  
2010 ◽  
Vol 36 (1) ◽  
pp. 10-13 ◽  
Author(s):  
George Milad
Keyword(s):  
Black Pad

scholarly journals Electroless deposition of Ni–P/Au coating on Cu substrate with improved corrosion resistance from Au(iii)–DMH based cyanide-free plating bath using hypophosphite as a reducing agent

RSC Advances ◽  
2021 ◽  
Vol 11 (62) ◽  
pp. 39153-39168
Author(s):  
Bo Wu ◽  
Baizhao Tan ◽  
Guizhen Tan ◽  
Ming Zeng ◽  
Jinyi Luo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Electroless Deposition ◽  
Reducing Agent ◽  
Gold Plating ◽  
Plating Bath ◽  
Cu Substrate ◽  
Black Pad ◽  
Electroless Gold

In the Au(iii)–DMH based cyanide-free electroless gold plating bath, the added hypophosphite inhibited the black pad and improved the corrosion resistance of the Cu/Ni–P/Au coating.

Electroless Ni plating solutions for reproducible black pad analyses.

2013 ◽  
Vol 2013 (1) ◽  
pp. 000397-000401
Author(s):  
K.H. Kim ◽  
Jin Yu
Keyword(s):  
Electron Microscopy ◽  
Large Scale ◽  
Electroless Nickel ◽  
Complexing Agent ◽  
Chemical Compositions ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Black Pad ◽  
Electroless Ni ◽  
Scanning Electron

A large-scale black pad of electroless nickel (EN) plated films were reproduced using pure chemicals: NiCl2·6H2O as the Ni source, NaH2PO2·H2O as the reducing agent, CH3COONa·3H2O and aminoacetate as the complexing agent and the buffer, respectively, and thiourea as the stabilizer. Plating baths with varying constituent compositions were investigated, and chemical compositions most suitable to the black pad study were sought. Cross-sectional scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses showed that the nickel-phosphorus (Ni-P) film made out of the #5 bath best demonstrated the typical characteristics of the black pad phenomenon after the immersion gold (IG) process. Additions of a low level of Thiourea (0.6mg/L), slightly larger amounts of glycine (1∼1.25x) and the complexing agent (1.25x) were suggested from the standpoint of the black pad formation of Ni-P films.

The root cause of black pad failure of solder joints with electroless Ni/Immersion gold plating

JOM ◽  
2006 ◽  
Vol 58 (6) ◽  
pp. 75-79 ◽  
Author(s):  
Kejun Zeng ◽  
Roger Stierman ◽  
Don Abbott ◽  
Masood Murtuza
Keyword(s):  
Solder Joints ◽  
Gold Plating ◽  
Root Cause ◽  
Black Pad ◽  
Electroless Ni
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