Railway carrier apparatus for semiconductor wafers

A railway carrier apparatus for transporting semiconductor wafers contained in a wafer cassette, each said wafer having front and rear sides, said wafer cassette having an open top, a bottom wall, first and second opposite side walls and internal walls, said first and second side walls extending from said bottom wall to said open top, said internal walls defining, respectively, a plurality of parallel grooves intermediate said first and second side walls for receiving said wafers in parallel aligned relationship along an axis extending between said first and second side walls and substantially perpendicular to said bottom wall, the front sides of the wafers facing said first side wall, the railway carrier apparatus including:

• a carrier for carrying the wafer cassette;
• a guide rail, disposed along a line of travel of the carrier, for supporting the carrier to guide the carrier along the line of travel;
• and drive means for driving the carrier along the line of travel, said carrier comprising:
• a carrier body slidably connected to the guide rail for movement along the guide rail;
• means for preventing damage to the front sides of said wafers comprising a bedplate member, having an upper face and mounted on the carrier body for supporting the wafer cassette on an upper face of said bedplate member such that the bottom wall of said cassette rests on said upper face with the wafers in said cassette being oriented in parallel with the line of travel of said carrier, the upper face of the bedplate member having one and the other side edges arranged to extend in a direction parallel to the line of travel, said one and the other side edges being disposed adjacent, respectively, to the first and second side walls of the cassette, the upper face being inclined at an angle larger than 0.degree. and not larger than 40.degree. with respect to a horizontal plane in such a manner that said one side edge is positioned at a higher level than the other side edge whereby the rear side of each said wafer in the cassette on said bedplate member leans against an adjacent internal wall of said cassette and the front side of each said wafer is spaced from the adjacent internal wall of said cassette;
• and the carrier further including an engaging member, attached to that portion of the bedplate member adjacent to the other side edge of the upper face of the bedplate member, for engaging with the wafer cassette so that the cassette is prevented from slipping down the upper face of the bedplate member.

A railway carrier apparatus for transporting semiconductor wafers contained in a wafer cassette, the railway carrier apparatus including:

• a carrier for carrying the wafer cassette;
• a guide rail, disposed along a line of travel of the carrier, for supporting the carrier to guide the carrier along the line of travel;
• and drive means for driving the carrier along the line of travel, said carrier comprising;
• a carrier body slidably connected to the guide rail for movement along the guide rail;
• a bedplate member, having an upper face and mounted on the carrier body, for supporting the wafer cassette on the upper face thereof, the upper face of the bedplate member having one and the other side edges, the upper face being inclined with respect to a horizontal plane in such a manner that said one side edge is positioned at a higher level than the other side edge;
• and a station assembly for shifting the carrier in a horizontal direction perpendicular to the line of travel.