Low-pressure plasma cleaning: a process for precision cleaning applications

Petasch, W.; Kegel, B.; Schmid, H.; Lendenmann, K; Keller, H. U.

doi:10.1016/s0257-8972(97)00143-6

Cited by 103 publications

(48 citation statements)

References 1 publication

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“…The lack of interfacial fractures with PC plasma reflow further confirms the effective removal of oxide and contaminant from the UBM and solder joint during plasma cleaning. 9,15,21) The partial interfacial fracture produced by insufficient bonding clearly explains the lower average shear strength of the NC plasma reflow specimens. The beneficial effect of Ar-10 vol%H 2 plasma cleaning also reflects the results from other studies such as increase of the bond strength of wire bump 11) and the adhesion strength of molding compound 12) by plasma cleaning.…”

Section: Shear Bond Strength and Fracture Surfacesmentioning

confidence: 97%

“…The spreading ratios were 75-76%, 64-70% and 53-64% for the plasma-cleaned plasma reflow specimens (hereafter called as PC plasma reflow), air reflow and plasma reflow without plasma cleaning (hereafter NC plasma reflow), respectively. Since the plasma cleaning was previously shown as effective to remove oxide and contaminants from a solid surface, 10,15) it was expected to improve the spreadability. Lee et al 11) also reported that the cleaning of Au die-pads by Ar, Ar/H 2 and O 2 plasma increased the wettability of de-ionized water on the pads.…”

Section: Spreading and Bonded Interfacesmentioning

confidence: 99%

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Effect of Plasma Cleaning on Fluxless Plasma Soldering of Pb-free Solder Balls on Si-wafer

Moon¹,

Kang²,

Jung³

et al. 2004

Mater. Trans.

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An Ar-10 vol%H 2 plasma was applied as a cleaning medium on UBMs (Under Bump Metallizations) to improve the bondability of solder balls prior to plasma reflow. Each UBM area comprised four layers deposited on a Si-wafer. Sequentially, the deposit comprised 0.4 mm of Al, 4 mm each of Ni and Cu, and 20 nm of Au from bottom to top of the metallization. Two compositions of lead-free solder balls (Sn-3.5 mass%Ag and Sn-3.5 mass%Ag-0.7 mass%Cu) and a lead containing one (Sn-37 mass%Pb) as a reference were selected for the experiment. The solder balls, of 500 mm diameter, were placed on the UBM's and fluxlessly soldered under Ar-10%H 2 plasma (with or without prior plasma cleaning). Additionally, air reflow with flux was also performed for comparison. Experimental results showed that the spreading ratios of the solders by plasma reflow after plasma cleaning were 20-40% higher than those plasma reflowed without cleaning. The shear strengths of the solder balls processed by the plasma-cleaned plasma reflow showed around 58-65 MPa, which is 60-80% and 15-35% higher than that of plasma reflow without plasma cleaning, and that of fluxed air reflow, respectively. From this study, plasma cleaning of UBM's using Ar-10%H 2 gas was shown to be quite effective to improve the bond strength of solder balls.

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Section: Shear Bond Strength and Fracture Surfacesmentioning

confidence: 97%

Section: Spreading and Bonded Interfacesmentioning

confidence: 99%

Effect of Plasma Cleaning on Fluxless Plasma Soldering of Pb-free Solder Balls on Si-wafer

Moon¹,

Kang²,

Jung³

et al. 2004

Mater. Trans.

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“…There is currently no effective, simple, and fast method dedicated to qualification and quantification of the surface cleanliness regarding to the presented amount of grease. The used precision methods are oriented towards controlled electrochemical cleaning [11] by oxygen radio-frequency plasma process and low-pressure plasma cleaning [12]. However, none of the used methods is dedicated to analysis of the surface pollution prior to the cleaning process.…”

Section: Introductionmentioning

confidence: 99%

Luminescence method − instrument used for detection of surface cleanliness

2015

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Preliminary notesThe process of surface treatment has a significant role in several industrial applications. Among the processes that most affect the quality of surface treatment are mainly the pre-treatment processes aimed at cleaning the processed surfaces. Degreasing of the treated surfaces has in this technological phase an important role. The article is devoted to quality control after surface pre-treatment. It deals with modern method for detecting grease-based surface contamination by the luminescence method. Impurities such as grease, oil and others have characteristic luminescence after illumination by UV light source. This principle can be used to determine the cleanliness of the part's surface thereby ensuring the quality of the observed surface. Surface cleanliness is a very important factor for the correct application of subsequent technological processes. Keywords: degreasing; grease detection; oil film; Recognoil device; surface cleanliness Metoda luminescencije -sredstvo za otkrivanje čistoće površinePrethodno priopćenje Postupak površinske obrade ima značajnu ulogu u nekoliko industrijskih primjena. Među postupcima koji najviše utječu na kvalitetu površinske obrade su uglavnom oni koji prethode obradi i odnose se na čišćenje obrađivanih površina. Važnu ulogu u toj tehnološkoj fazi ima odmašćivanje obrađivanih površina. Članak se bavi kontrolom kvalitete nakon prethodne obrade površine. Opisuje suvremenu metodu za otkrivanje površine kontaminirane masnoćom primjenom metode luminescencije (svjetlucanja). Kod nečistoća kao što su masnoća, ulje i druge, pojavljuje se karakteristično svjetlucanje nakon izlaganja UV zrakama. Taj se princip može primijeniti za određivanje čistoće tog dijela površine i tako osigurati kvalitetu tretirane površine. Čistoća površine je vrlo važan čimbenik za ispravnu primjenu narednih tehnoloških postupaka.

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“…These interesting properties of cathode spots are attractive because of the total lack of harmful environmental effects. [1][2][3][4][5] Vacuum arc cleaning is friendly to the natural environment and to factory workers, because it eliminates oxide by the application of high temperatures, which differs from the current chemical treatments. Additionally, it causes no surface contamination such as residual abrasives or chemicals associated with the blasting method or pickling method, respectively.…”

Section: Introductionmentioning

confidence: 99%