Wafer purging-type shelf assembly and buffer module having the same

A wafer purging-type shelf assembly comprising:

• a storage housing including a receiving space;
• a shelf formed to support a wafer receiving container in the receiving space;
• a supply nozzle configured to be connected to an injection port of the wafer receiving container;
• and
• a gas supply line configured to supply an inert gas discharged from a factory gas facility to the wafer receiving container through the supply nozzle,
• wherein the gas supply line includes a proportional pressure control valve unit, a shelf-dedicated regulator, a flow rate sensor and a filter wherein the proportional pressure control valve unit adjusts a supply flow rate of the inert gas to the wafer receiving container by an area control method;
• wherein the proportional pressure control valve unit includes:
• a valve housing including an input port, a relief port and an output port;
• and
• a piezo valve seat, a restoring spring being installed inside the valve housing and a pressure sensor being outside the valve housing and the piezo valve seat adjusting a flow area of the inert gas through the input port according to an input voltage to control a flow rate of the inert gas output through the output port.