A laminate countertop is an acceptable base for ceramic tile, but think carefully before you attempt it. If your counter has curved edges, as most do, you'll have to grind off the raised bead at the lip with a belt sander and you won't be able to tile the backsplash without cutting off the curved top edge. Some tile stores carry special tiles that will wrap around the front edge, but the selection will be limited. If you choose to go ahead, first rough up the laminate with 100-grit sandpaper and adhere the tile with an adhesive that's formulated to bond to plastic laminate (look for the adhesive at tile stores).
Frankly, this is a dicey proposition and we don't recommend it. Some tiles can still come loose, and the grout may crack, especially at the front edge. The best course is to tear off the old top and install a solid 3/4-in. plywood underlayment and a layer of tile backer board before tiling. It's less work than it sounds and will ensure a long-lasting tile countertop.