yttria doped aln substrates purchased from carborundum company electronic materials group substrates division 2050 cory drive sanborn n y 14132 at the various aln surface treatment conditions at the maximum adhesion condition the observed thickness of the surface alumina is 2 0 microns significantly thinner than either of the 5 0 8 0 microns reported in the aforementioned kuromitsu et al paper or the 4 0 microns reported in the aforementioned iwase et al paper and attained only as a result of direct bonding au to aln through use of other metallics thus high peel strength is acquired without use of additional metallics and is consistent with the uncrazed sparser and thinner al 2 o 3 lamina achieved by the invention this new laminate demonstrates that the thermal conduction of aln dominates the al 2 o 3 achieving a metallized ceramic substrate not quite possessing all the attributes of dbc on beryllia but of significantly better thermal character than either of the prior known dbc on aln or dbc on alumina also significant is the fact that the present invention realizes a combination of highly conductive metallization on ceramic which exhibits high thermal conductivity low permittivity and because of the increased yttria doping of the aln high mechanical strength the following table details more extensively the empirical results of the invention ______________________________________table of peel strength of copper film 5 mil thickness that has beenapplied by dbc on preoxidized yttria doped alnsubstrates at specific conditionsconditions peel strength lbs in ______________________________________as received 1 21 o sub 2 100 n.