Three-dimensional printing with build plates having reduced pressure and/or channels for increased fluid flow

Abstract

A method and an apparatus of forming a three-dimensional object, wherein the method includes providing a carrier and an optically transparent member having a build surface, said carrier and said build surface defining a build region therebetween; filling said build region with a polymerizable liquid, continuously or intermittently irradiating said build region with light through said optically transparent member to form a solid polymer from said polymerizable liquid, continuously or intermittently advancing (e.g., sequentially or concurrently with said irradiating step) said carrier away from said build surface to form said three-dimensional object from said solid polymer, said optically transparent member comprising a build plate for a three-dimensional printer comprising: an optically transparent first channel layer; an optically transparent, gas permeable second channel layer on the first channel layer; and a flexible, optically transparent, gas-permeable sheet having an upper and lower surface, the sheet upper surface comprising a build surface for forming a three-dimensional object, the sheet lower surface being positioned on the second channel layer.