Copper interfaces

The real parts of k-z and kkz tell us how far the electric and magnetic fields penetrate into the metal (a) and vacuum (b), respectively. Figure 5 shows the distance in which these fields fall to 1/e of their value at the surface for a vacuum-copper interface. The fields extend a much greater distance into the vacuum than they do into the metal. 

A method apparently fundamentally related to the above is illustrated by the fractional catalytic dehydration of di-2-butanol observed by Schwab and Rudolph.91 The alcohol recovered after partial thermal dehydration upon a film of copper supported on powdered d- or 1-quartz was faintly active in the same sense as the quartz. Similar results were noted after partial catalytic oxidation on the same surfaces. These results have not been explained fully it is possible that each of the two active forms of the alcohol is adsorbed momentarily on the quartz-copper interface the two diastereoisomeric combinations thus formed then react at different rates. The method is not practical in its present form. 

STAFSTROMETAL. Model Systems for Polyimide-on-Copper Interface 313... 

STAFSTROM ET AL. Model Systems for Pofyimide-on-Copper Interface... 

BODOETAL. Photoelectron Spectroscopy of Polyimide—Copper Interface 335... 

BODOETAL. Photoelectron Spectroscopy ofPolyimide—Copper Interface 337... 

In this study, we have used a set of polyimide model molecules to obtain information about possible interactions at the polyimide copper interface. Benzene, phthalimide (PIM), benzene-phthalimide (BPIM), methyl-phthalimide (MPIM), and malonamid (MAM) were deposited in ultrahigh vacuum (UHV) onto clean polycrystalline copper substrates, and the measurements were performed by means of XPS and UPS. 

Characterization of the Poly(ether ether ketone)—Copper Interface... 

To monitor both the copper and the polymer species during a PEEK/copper interface reaction, a PEEK overlayer thinner than 80 A, the approximate sampling depth of ESCA, was required. Centrifugal casting (3000 rpm for 15 sec) of an extract of PEEK in hexafluoroisopropanol (HFIP) onto copper disks proved successful for obtaining samples on which both PEEK and copper species could be detected by ESCA. The extract was obtained by passing a 20-30 wt. % suspension of PEEK in HFIP through a 0.5 pm Teflon filter. The solubility of a representative fraction of the PEEK in HFIP was verified by IR analysis. Comparison of the IR spectra from a PEEK/KBr pellet and the evaporated filtration product indicated identical spectra. 

Due to surface temperature fluctuations during lamination and the resulted changes in photoresist/copper interface adhesion, printed circuit yield is inversely proportional to FR-4 substrate thickness. Preheating the substrates, however, would improve the adhesion and result in a higher yield for the printed circuits. 

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