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KR-102963495-B1 - Panel-type Buffer Tank with Pressure-resistant Structure and Semiconductor Chiller System Using the Same

KR102963495B1KR 102963495 B1KR102963495 B1KR 102963495B1KR-102963495-B1

Abstract

The present invention relates to a panel-type buffer tank with a pressure-resistant structure for solving the cavitation problem of a semiconductor chiller system. The buffer tank comprises a pair of opposing first panels, a reinforcing member with a grid beam structure disposed between the first panels to support internal pressure, a brine inlet port and an outlet port, and a pressurized connection port. The reinforcing member with a grid beam structure prevents deformation of the first panels at a pressure of 8 bar or higher, thereby enabling the chiller's circulation system to be converted from an open type to a closed type. According to the present invention, cavitation of the pump is prevented, evaporation and condensation of the brine are prevented, and space efficiency can be improved by more than 20% compared to a cylindrical pressure vessel.

Inventors

  • 방진영
  • 송호경
  • 강태웅

Assignees

  • (주)쏠라딘

Dates

Publication Date
20260512
Application Date
20251023

Claims (11)

  1. In a buffer tank for a semiconductor chiller, A plurality of square pipes having multiple through holes formed on their upper and lower surfaces are stacked such that the through holes are aligned with one another, and the contact portions of adjacent square pipes are welded to form an integrated grid structure, wherein the side walls of the stacked square pipes form a pair of first panels facing each other; A pair of second panels welded to the front and rear portions of the above-mentioned square pipe laminate; A pair of third panels welded to the upper and lower parts of the above-mentioned square pipe laminate; The above-mentioned square pipe laminate, the second panel, and the third panel form a sealed structure, and the grid between the penetration portions of the square pipes forms an internal reinforcing structure that prevents deformation of the second panel and the third panel due to internal pressure; Brine inlet port and brine outlet port; and including a pressurized connection port, Panel-type buffer tank with internal pressure structure.
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  4. In paragraph 1, The grid between the penetration portions of the above-mentioned pipes reduces the unsupported span of the second and third panels to support an internal pressure of 8 bar or more. Panel-type buffer tank with internal pressure structure.
  5. In paragraph 1, The above square pipe is formed of STS material, Panel-type buffer tank with internal pressure structure.
  6. In paragraph 1, A relief valve formed on at least one of the above panels; and including additional level connection ports, Panel-type buffer tank with internal pressure structure.
  7. In paragraph 1, A perforated plate further comprising a positioned between the brine inlet port and the outlet port in the internal space to control the flow of brine, Panel-type buffer tank with internal pressure structure.
  8. A panel-type buffer tank according to any one of paragraphs 1, 4 through 7; A pressurizing device connected to a pressurizing connection port of the buffer tank to pressurize the interior of the buffer tank; A cooling line fluidly communicating with the above buffer tank; and A pump comprising the above cooling line, Semiconductor chiller system.
  9. In paragraph 8, The above pressurizing device pressurizes the inside of the buffer tank to 1.0 barg or more to prevent cavitation of the pump, and The above system forms a closed circulation system to prevent the evaporation and condensation of brine, Semiconductor chiller system.
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Description

Panel-type Buffer Tank with Pressure-Resistant Structure and Semiconductor Chiller System Using the Same An embodiment of the present invention relates to a buffer tank of a chiller system used in a semiconductor manufacturing process, and more specifically, to a panel-type buffer tank that provides pressure resistance of 8 bar or more by having an internal reinforcing material with a grid beam structure, and a semiconductor chiller system using the same. In the semiconductor manufacturing process, semiconductor process equipment must always maintain a constant temperature inside the chamber, and the equipment responsible for this temperature maintenance is a semiconductor chiller. A chiller may include a refrigeration cycle using a refrigerant and a cooling cycle using a coolant to maintain a constant temperature inside a chamber of semiconductor process equipment. In order to perform the refrigeration cycle, a compressor, a condenser, an expansion valve, and an evaporator are basically required, and the refrigerant cooled through the refrigeration cycle can exchange heat with the coolant of the cooling cycle through the evaporator. Meanwhile, the coolant, which has been heat-exchanged to a low temperature through an evaporator, circulates through a cooling cycle including a pump and a heater and is set to the temperature required for the chamber of the semiconductor process equipment, thereby allowing the chamber temperature of the semiconductor process equipment to be maintained at a constant level. Buffer tanks in semiconductor chiller systems have traditionally adopted a cylindrical structure, or, in the case of panel types, have been manufactured with an open structure exposed to atmospheric pressure. Cylindrical pressure vessels are structurally efficient against internal pressure, but they have the problem of large dead space in the limited space of semiconductor fabs. When a panel-type (rectangular) structure is adopted for space efficiency, flat surfaces struggle to withstand pressure, so they were manufactured exclusively as open-type tanks. Since these open-type panel tanks operate under atmospheric pressure, problems such as pump cavitation, brine evaporation, and condensation occur. Therefore, a new structure is required that enables closed-type pressurized operation while maintaining the space efficiency of a panel type. However, since the open tank of a semiconductor chiller is structurally exposed to the atmosphere and operates under atmospheric pressure, the pump has a limitation in that it relies solely on the effective suction head. In particular, a localized pressure drop may occur on the pump suction side due to the pump's rotational speed. At this time, the coolant on the pump suction side boils at a temperature lower than its original boiling point due to the vapor pressure lowered by the pressure drop, causing cavitation in the pump. If bubbles generated by this cavitation are sucked into the pump, problems such as equipment failure and shortened lifespan may occur due to overheating or damage to the pump. In addition, due to the nature of the liquid level inside the tank being exposed, if the temperature of the brine is maintained below the dew point during a low-temperature process, humid air may begin to condense on the surface of the brine, causing a problem where the brine and water mix. As prior art, U.S. Patent 6,477,855 B1 (November 12, 2002) presented a vent line to prevent vaporization of the coolant and prevent cavitation in a chiller tank system, but it still has the limitations of an open structure. Korean Patent KR 100754842 B1 (September 4, 2007) presented a method for temperature control through a hot gas supply line in a chiller device for semiconductor process equipment, but it failed to solve the cavitation problem caused by pressure drop. Korean Patent KR 101501176 B1 (March 10, 2015) proposed a method of directly supplying refrigerant to the process chamber in a chiller for semiconductor processes, but no structural improvement was made to the buffer tank. Korean Patent KR 100385450 B1 (May 27, 2003) presents a method to prevent the vaporization of a coolant by improving the tank interior to a vertical structure in a chiller for semiconductor processes, but it does not provide a solution for the internal pressure structure. Therefore, conventional technologies have all failed to overcome the fundamental limitations of open tank structures, and in particular, measures to secure pressure resistance through structural improvements have not been presented. FIG. 1 is a side view showing the exterior of a panel-type buffer tank with a pressure-resistant structure according to one embodiment of the present invention. FIG. 2 is an assembled perspective view showing the interior of a panel-type buffer tank with a pressure-resistant structure according to one embodiment of the present invention with one side panel removed. FIG. 3 is an assembly diagram showing the manufac