Patent ID: 9677320
Date: 2017-06-13
CPC Classifications: E06B,Y02A,Y02B

Claim:
1. A method of making a vacuum insulating glass (VIG) window unit, the method comprising: inserting into an oven a unit comprising first and second substantially parallel spaced-apart glass substrates, a gap defined by an area between the spaced apart substrates, a plurality of spacers provided in the gap between the first and second glass substrates, a pump-out port formed in the first or second substrate, one or more edge portions of the first and second substrates to be sealed, and a frit provided at least partially between the first and second glass substrates for sealing said one or more edge portions to be sealed; pre-heating the unit substantially in its entirety to at least one intermediate temperature, each said intermediate temperature in the pre-heating being below a melting point of the first and second substrates and below a melting point of the frit; providing near infrared (IR) radiation at a near IR wavelength of 1.1 to 1.4 μm to the unit proximate to the one or more edge portions to be sealed so as to provide a localized temperature of from about 350 to 500 degrees C. directly onto the frit so as to at least partially melt the frit, the near IR heat being provided to the unit such that at least some areas of the unit not proximate to the edge portions to be sealed are kept at a temperature(s) below frit-melting temperature; and allowing the frit to harden; evacuating the gap of the unit to at least one reduced pressure, said reduced pressure being below atmospheric; and sealing the pump-out port of the unit, in a port sealing zone, during or after the evacuating of the gap to the reduced pressure in forming the vacuum insulating glass (VIG) unit, wherein temperature in the port sealing zone is about 200 degrees C.