William Vincent Dumas

Aqueous pretreatments of polyetherimide to facilitate the bonding of electrolessly deposited copper

A chemical method for pretreating polyetherimide substrates to promote adhesion to copper is described. The process consists of cleaning the polymer surface followed by surface normalization, debris solubilization, and adhesion promotion via chemical modification of the polymer surface. Classes of candidates for each of the major steps are described and the optimal agents assembled into a recommended procedure. Peel strengths between 150-210 g mm-1 for copper to polyetherimide were achieved utilizing the suggested scheme. Scanning electron microscopic and X-ray photoelectron spectroscopic analyses were employed to investigate changes in the polymer surface and chemistry during processing. Metallized specimens were examined after 90° peel testing and the failure locus found to be within the polymer layer.

Aqueous pretreatment of polyetherimide to facilitate the bonding of electrolessly deposited metals. Part 2: Solubilizer-free systems

An aqueous method for chemically pretreating polyetherimide substrates to promote adhesion to electrolessly deposited copper or nickel is described. The process consists of cleaning the polymer surface followed by surface normalization and debris removal. In contrast to previously developed processes, no separate adhesion promotion step is required. Peel strengths between 150-250 and 120-150 g/mm were achieved for copper and nickel, respectively. Scanning electron microscopy and X-ray photoelectron spectroscopy were utilized to investigate changes in the polymer surface morphology and chemistry during processing. Possible candidates for the different steps are presented, as are analyses of the failure loci following peel strength assessment.

Characterization of Surface Modifications during Metallization of Polyetherimide

The chemical and compositional modifications of a polyetherimide surface during metallization processes have been monitored using x-ray photoelectron spectroscopy (XPS). The following aspects will be discussed: 1) detection of contaminants on the polymer surface and the effectiveness of various cleaning agents; 2) determination of the degree of imide hydrolysis; 3) quantification of the coverages of metallization catalysts using Rutherford backscattering spectrometry (RBS) as a calibration method; 4) measurement of the changes in catalyst composition (colloidal Pd/Sn) during sensitization and acceleration steps; and 5) verification of the cause of leakage current between isolated conductor runs.