CRYSTALLIZATION OF BORIC-ACID ON LOW-K GLASS PLUS CERAMIC GREEN TAPES

Crystallization at room temperature on the surface of low-k glass+cera mic green tapes, containing a low-softening-point borosilicate glass a nd a high-softening-point high silica glass has been investigated. Res ults of diffuse reflectance Fourier transform infrared (FTIR) and Rama n microprobe spectra show that the crystals are boric acid: formed by reaction of the boric oxide in the borosilicate glass with water in an ambient atmosphere. A faster and greater degree of crystallization is observed with increased level of relative humidity in the ambient atm osphere. To minimize the formation of boric acid crystals on the green tapes, a relative humidity of 15% or less is required.