US 2024/0230232 A1Published application

Gas control system for reflow furnace and reflow furnace

AssigneeIllinois Tool Works Inc.

InventorsYuexin Chen, Yuwei Wang, Dong Zhang

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Abstract

The present application discloses a gas control system for a reflow oven, a hearth thereof comprising a preheating zone, a peak zone and a cooling zone. The gas control system comprises: an oxygen detection apparatus, a first valve apparatus, a second valve apparatus and a controller. The controller is configured to control the degree of opening of the first valve apparatus and/or the second valve apparatus when the oxygen concentration detected by the oxygen detection apparatus does not satisfy a preset value, in order to enable the oxygen concentration in the peak zone to satisfy the preset value by adjusting the flow rate of working gas and/or air inputted into the peak zone. The gas control system and reflow oven of the present application first perform rough adjustment of gas in the hearth, such that the oxygen concentration in the hearth is substantially close to the preset value. The oxygen concentration in the peak zone of the hearth is then adjusted precisely by means of the first valve apparatus and second valve apparatus. Thus, even though the amount of oxygen in air entering the hearth is indeterminate, the oxygen concentration of the peak zone will not be affected, so the quality of circuit board soldering can be increased in a stable fashion.

Claims10

Dependent claims

A gas control system for a reflow oven, a hearth (112) of the reflow oven (110) containing a gas, the gas comprising oxygen and a working gas, and the hearth (112) comprising a preheating zone (101), a peak zone (103) and a cooling zone (105), characterized in that the gas control system (100) comprises:

an oxygen detection apparatus (120), the oxygen detection apparatus (120) being configured to detect the oxygen concentration in the peak zone (103);
a first valve apparatus (131), the first valve apparatus (131) being configured to fluidly connect a working gas source (140) to the peak zone (103) of the hearth (112) in a controllable fashion;
a second valve apparatus (132), the second valve apparatus (132) being configured to fluidly connect an air source (150) to the peak zone (103) of the hearth (112) in a controllable fashion;
and
a controller (122), the controller (122) being in communicative connection with the oxygen detection apparatus (120), the first valve apparatus (131) and the second valve apparatus (132);
and the controller (122) being configured to control the degree of opening of the first valve apparatus (131) and/or the second valve apparatus (132) when the oxygen concentration detected by the oxygen detection apparatus (120) does not satisfy a preset value, in order to enable the oxygen concentration in the peak zone (103) to satisfy the preset value by adjusting the flow rate of working gas and/or air inputted into the peak zone (103) of the hearth (112).

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/560,291Filed 20 May 2022
Priority: CN 202110562988.024 May 2021
Published: 11 Jul 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

F27B 9/3005
Details, accessories or equipment specially adapted for furnaces of these types: arrangements for circulating gases
F27B 9/045
Adapted for treating the charge in vacuum or special atmosphere: furnaces with controlled atmosphere
F27B 9/20
Characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment: the charge…
F27B 9/40
Details, accessories or equipment specially adapted for furnaces of these types: arrangements of controlling or monitoring devices