Solder reflow with optical endpoint control

Abstract

A solder reflow system (100) includes a vacuum chamber (104) and a sample chuck (106) in the vacuum chamber (104) for supporting a semiconductor wafer (102) to be processed. The solder reflow system (100) further includes: a heating element (108) coupled to the vacuum chamber (104) and configured to heat the semiconductor wafer (102); a thermocouple (112) connected to the sample chuck (106) to measure a temperature of the semiconductor wafer (102); and a pyrometer (114) positioned to detect an optical signal (116) from the semiconductor wafer (102) to estimate the temperature of the semiconductor wafer (102). The control system (122) is configured to: control the heating element (108) to heat the semiconductor wafer (102); during the heating of the semiconductor wafer (102), obtain one or more measurements of the temperature of the semiconductor wafer (102) from the thermocouple (112) and obtain one or more estimates of the temperature of the semiconductor wafer (102) from the pyrometer (114); and determine a modification to the heating of the semiconductor wafer (102) based on the obtained measurements. A solder reflow system (100) that includes a vacuum chamber (104) and a sample chuck (106) in the vacuum chamber (104) to support a semiconductor wafer (102) to be processed. The solder reflow system (100) further include a heating element (108) coupled to the vacuum chamber (104) and configured to heat the semiconductor wafer (102), a thermocouple (112) connected to the sample chuck (106) to measure a temperature of the semiconductor wafer (102), a pyrometer (114) positioned to detect an optical signal (116) from the semiconductor wafer (102) to estimate the temperature of the semiconductor wafer (102).The control system (122) is configured to control the heating element (108) to heat the semiconductor wafer (102), obtain one or more measurements of the temperature of the semiconductor wafer (102) from the thermocouple (112) and one or more estimates of the temperature of the semiconductor wafer (102) from the pyrometer (114) during the heating of the semiconductor wafer (102), and determine a modification of the heating of the semiconductor wafer (102) based on the obtained measurements.

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