Here is what I do. I have all this handy.
I take two pcs. of glass. I measure the chip with my calipers. I then take washers the same thickness and place them around the chip. I then put the other pc. of glass on top and warm it with a heat gun on a low setting. I press on the glass until it will not push down anymore. The washers prevent the chip from getting thinner than I want.
Barry