Recessed heating plate structure

Abstract

A recessed heating plate structure includes: a heating plate; the upper surface of the heating plate is a recessed area formed by a groove, a heated object is placed in the groove for heating, and a confined air layer is formed above the heated object, forming a thermal pocket above it when the heated object is heated. By controlling the geometric depth of the confined air layer to keep its Rayleigh number below the critical value for natural convection, air convection is suppressed and a heat transfer mechanism dominated by conduction is maintained, thereby improving the temperature uniformity of the heated object's edges and corners and reducing temperature fluctuations.

Claims

1. A recessed heating plate structure, suitable for heating processes requiring precise temperature control of thin heated objects, comprising: A heating plate; the upper surface of the heating plate is a recessed area formed by a groove, and a heated object is placed in the groove for heating. A confined air layer is formed above the heated object, so that a thermal pocket is formed above the heated object when it is heated. The recessed depth of the groove, the distance between the edge of the heated object and the inner wall of the groove, and the temperature conditions of the upper surface of the heating plate are configured so that the air convection forming the thermal pocket in the confined air layer is geometrically restricted, and large-scale or unstable circulating convection flow is avoided. In this way, the chance of a large amount of cold air flowing into the thermal pocket is reduced, the local cooling phenomenon caused by enhanced convection on the surface of the heated object is reduced, thereby improving the overall temperature uniformity and thermal stability.

2. The sunken heating plate structure as described in claim 1, wherein, The depth of the recess is designed based on at least one of the following parameters: the planar dimensions of the heated object, the operating temperature of the heated object, and the material of the heated object.

3. The sunken heating plate structure as described in claim 1, wherein, The confined air layer has a characteristic length, which is defined as the depth of the groove minus the thickness of the heated object. The geometry of the confined air layer is designed such that its Rayleigh number satisfies the following relationship: where is the critical Rayleigh number for natural convection, thereby suppressing natural convection when a thermal cavity is formed within the confined air layer.

4. The sunken heating plate structure as described in claim 1, wherein, It also includes a cavity in which the heating plate is located to reduce the impact of external airflow on the heating process.

5. The sunken heating plate structure as described in claim 1, wherein, The closer the edge of the heated object is to the inner wall of the groove, the better the heating effect of the edge of the heated object.

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