Journal of Adhesion Science and Technology, Vol.9, No.10, 1319-1342, 1995
ELECTROPLATING ONTO INORGANIC GLASS SURFACES PART .2. MECHANICAL TREATMENT TO IMPROVE ADHESION
The metallization of glass surfaces was carried out using chemical and mechanical methods to achieve a roughened surface. Comparable to ABS polymers, where chemical treatment resulted in a selective etching of the chemically weaker phase and the adhesion mechanism was due to mechanical keying of the metal into the etched caverns, a finely structured glass surface must be properly prepared to ensure metal anchoring. For chemical treatment, melts of sodium and potassium hydroxide and potassium hydrogen sulfate were used. The treatment did not result in a finely roughened surface structure and no improvement in adhesion could be achieved. A mechanical treatment (using abrasive blast with Al2O3 of various grain sizes) produced a uniformly roughened glass surface but only with a combination of mechanical and chemical treatment, crevices comparable to the caverns produced in ABS-electroplating were attained. For chemical treatment, solutions of ammonium hydrogen fluoride of various concentrations were used. Soda-lime glass could be etched more easily than the borosilicate glass and gave higher peel-strengths.