The present invention includes a tool (300) for positioning optical waveguide fibers (310) on an adhesive coated substrate (302) including a holder (301) and a pressure source. The holder (301) includes a chamber (314) coupled to the pressure source and multiple recesses (308) configured to position the optical waveguide fibers (310). Each recess (308) includes a reference surface (312) and is connected to the chamber (314) by a passageway (316). The pressure source is configured to selectively increase and decrease the pressure in the chamber (314). The invention also includes a method of making optical waveguide fiber array blocks using the tool (300).