TWI393851B - Vaccum oven - Google Patents

Description

Vacuum oven

The present invention relates to a vacuum oven, and more particularly to a vacuum oven that can be rapidly cooled.

A printed circuit board is a substrate for assembling electronic parts. In the manufacturing process of the printed circuit board, it is necessary to bake the semi-finished printed circuit board several times and then perform subsequent processing.

The baking process is to place the printed circuit board in a high temperature environment for a period of time, usually in an aerobic environment. However, during the long-time baking process, the anti-oxidation layer on the surface of the copper foil of the copper-clad substrate is decomposed at a high temperature, which causes the surface of the copper foil to be oxidized and discolored, which seriously affects the appearance quality of the printed circuit board.

Baking the printed circuit board with a vacuum oven can solve the above problem. Since the vacuum oven will evacuate the air in the chamber before heating, the pressure is close to the vacuum state, and further filled with a protective gas such as nitrogen to retain the residual oxygen in the chamber. At the same time of further dilution, the protective gas can effectively prevent the oxidation-reduction reaction between the copper foil and the trace oxygen. Even if the high temperature destroys the oxidation resistant layer on the surface of the copper foil, the copper foil is not oxidized and discolored. However, after the completion of the baking of the vacuum oven, it takes a long time to perform cooling, resulting in low baking efficiency.

In view of this, it is necessary to provide a vacuum oven capable of rapid cooling, which not only shortens the cooling time, improves the baking efficiency, but also improves the airtightness to prevent the product from being oxidized.

The quick-cooling vacuum oven will now be described in the context of a specific embodiment.

A vacuum oven includes a box body, an insulated outer wall, a gas transfer device, and a temperature control device. The case has a first side wall, a second side wall and a third side wall. The heat insulating outer wall surrounds the box body, and has first side walls, second side walls and third side walls corresponding to the first, second and third side walls of the box body. The gas transfer device is in communication with the tank. The temperature control device is used to control the temperature inside the cabinet. The rapidly cooled vacuum oven also includes a cooling device. The cooling device includes a cooling water jacket, and at least one water inlet and at least two water outlets disposed on the cooling water jacket. The cooling water jacket is disposed between the box body and the heat insulating outer wall, the cooling water jacket has a first interlayer, and a second interlayer and a third interlayer connected to the first interlayer, the second interlayer being disposed opposite to the third interlayer And together with the first interlayer to form a cavity.

Compared with the prior art, the vacuum oven incorporates a cooling device, which saves cooling time, thereby shortening the baking cycle and improving drying efficiency. Moreover, the baking operation is carried out under the condition of drawing to an approximate vacuum and filling with nitrogen, thereby providing good airtightness, so that the baked product has good appearance quality.

10‧‧‧ cabinet

30‧‧‧Cooling device

60‧‧‧Circulating wind installation

12, 22‧‧‧ first side wall

16, 26‧‧‧ second side wall

14, 24‧‧‧ third side wall

31‧‧‧ Cooling water jacket

39‧‧‧Water inlet

54‧‧‧heater

58‧‧‧Solid relay

64‧‧‧Wind wheel

71‧‧‧Exhaust device

73, 76‧‧‧ trachea

20‧‧‧Insulated outer wall

50‧‧‧ Temperature control device

70‧‧‧ gas transfer device

32‧‧‧First mezzanine

36‧‧‧Second mezzanine

34‧‧‧ third mezzanine

33, 35, 37‧‧ ‧ water outlet

52‧‧‧temperature sensor

56‧‧‧ thermostat

62‧‧‧Electric motor

66‧‧‧Magnetic Couplings

72‧‧‧Inflator

74‧‧‧ gas cylinder

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view showing the structure of a vacuum oven provided in an embodiment of the present invention.

2 is a top plan view showing the structure of a vacuum oven provided by an embodiment of the present invention.

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

1 is a cross-sectional view showing the structure of a vacuum oven according to the present embodiment, which includes a case 10, a heat insulating outer wall 20, a temperature control device 50, a circulation air device 60, a gas transfer device 70, and a cooling device 30.

Referring to FIG. 2, the casing 10 includes a first sidewall 12, a second sidewall 16 and a third sidewall 14, and the first sidewall 12, the second sidewall 16 and the third sidewall 14 define a cavity.

The heat insulating outer wall 20 is disposed around the casing 10 and has a first side wall 12 and a second side respectively opposite to the casing 10 The wall 16 and the third side wall 14 correspond to the first side wall 22, the second side wall 26 and the third side wall 24. A cooling device 30 is provided between the insulated outer wall 20 and the casing 10.

The temperature control device 50 includes a temperature sensor 52 located on the inner wall of the casing 10, which may be a thermocouple, a thermostat 56 and a solid state relay 58 located outside the insulated outer wall 20, and a thermal insulation outer wall 20 and a casing. A heater 54 in the region between 10, which may be a heater such as metal or infrared.

The circulating air device 60 is located on one side of the casing 10 and includes an electric motor 62, a magnetic coupling 66 and a rotor 64. The motor 62 is disposed outside the heat insulating outer wall 20. The magnetic coupling 66 is connected to the motor 62 at one end and extends to the region between the heat insulating outer wall 20 and the casing 10 at the other end. The wind wheel 64 is connected to the magnetic body. The coupling 66 is located inside the insulated outer wall 20 and outside the casing 10. The wind wheel 64 is used to accelerate the gas flow in the tank 10 to facilitate heat transfer; the motor 62 is used to drive the wind wheel 64 to operate; the magnetic coupling 66 is driven between the motor 62 and the wind wheel 64 to ensure the box The body 10 has good airtightness.

The gas transfer device 70 includes an air pumping device 71 and an inflator device 72. The air pumping device 71 includes a vacuum pump 75 and a gas pipe 73. The vacuum pump 75 communicates with the tank 10 through a gas pipe 73. The gas inflator 72 includes a shielding gas. The cylinder 74 and a gas pipe 76 communicate with the tank 10 through the gas pipe 76. In this embodiment, the shielding gas is nitrogen.

The cooling device 30 includes a cooling water jacket 31 provided with a water inlet 39, a water outlet 33, a water outlet 35, and a water outlet 37. When the water outlets 33 and 35 are used for cooling, the cooling water can be discharged, and when the water outlet 37 is used for cooling, the cooling water remaining in the cooling water jacket 31 is drained. In the present embodiment, the cooling water jacket 31 and the casing 10 are spaced apart by a certain distance. Therefore, the cooling water jacket 31 is mainly used for cooling the gas between the heat insulating outer wall 20 and the casing 10. However, it can be understood that the cooling water jacket 31 can also cover the first side wall 12, the second side wall 16, and the third side wall 14 of the casing 10 and directly contact the casing 10, thereby accelerating the cooling of the gas in the casing 10.

Referring to FIG. 2, the cooling water jacket 31 has a first interlayer 32, a second interlayer 36 and a third interlayer 34 communicating with the first interlayer 32. The two sidewalls of the first interlayer 32 are respectively opposite to the first sidewall of the casing. 12 and the first side wall 22 of the heat insulating outer wall are adjacent to each other; the two side walls of the second interlayer 36 are respectively adjacent to the second side wall 16 of the box body and the second side wall 26 of the heat insulating outer wall; two of the third interlayers 34 The side walls are adjacent to the third side wall 14 of the case and the third side wall 24 of the insulated outer wall, respectively.

1 and 2, the water outlet 33 is disposed adjacent to the heater 54, and the water outlet 35 is located at one end of the heater 54 adjacent to the first interlayer 32 of the cooling jacket and the third interlayer 34. The water outlets 33 and 35 can be opened normally. The water outlet 37 is used to discharge the cooling water remaining in 31 after the use of the cooling device, so that the position of 37 is such that the water in 31 can all flow out. In this embodiment, it is near the bottom of the casing 10, i.e., one end farthest from the heater 54. The water inlet 39 is disposed away from the water outlet 35. In this embodiment, it is located below the water outlet 33, that is, the contact zone between the first interlayer 32 and the second interlayer 36 of the cooling water jacket 31 is farthest from the heater 54 due to In the region between the casing 10 and the insulated outer wall 20, the temperature closer to the heater 54 is higher, so the cooling water jacket 31 constitutes a countercurrent cooling system with higher cooling efficiency. The water outlet 37 is located below the water outlet 35, that is, one end of the contact zone between the first interlayer 32 and the second interlayer 34 of the cooling water jacket 31 farthest from the heater 54.

Prior to baking, the inside of the casing 10 is evacuated using an air extracting device 71, and then the inside of the casing 10 is filled with nitrogen gas using an inflator 72. The heater 54 is then turned on to heat the gas in the tank 10, and the heating process is controlled by the thermostat 56 and the solid state relay 58. At the same time, the circulation air device 60 is used to accelerate the gas circulation in the casing 10.

When the baking is completed and rapid cooling is required, the water outlet 37 is closed, and the water inlet 39 is opened, so that the cooling water enters the cooling water jacket from the water inlet 39, and the heat of the casing is taken out, and then discharged from the water outlet 35 and the water outlet 33. When the cooling is completed, the water inlet 39 is closed, and the water outlet 37 is opened to drain the remaining cooling water.

In addition, those skilled in the art can make other changes within the spirit of the present invention, appropriately change the position distribution of the cooling water jacket, or change the position or number of the inlet and outlet, etc., as long as they do not deviate from the technology of the present invention. The effect can be. All changes made in accordance with the spirit of the invention are intended to be included within the scope of the invention.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧ cabinet

30‧‧‧Cooling device

60‧‧‧Circulating wind installation

31‧‧‧ Cooling water jacket

39‧‧‧Water inlet

54‧‧‧heater

58‧‧‧Solid relay

64‧‧‧Wind wheel

71‧‧‧Exhaust device

73, 76‧‧‧ trachea

75‧‧‧vacuum pump

20‧‧‧Insulated outer wall

50‧‧‧ Temperature control device

70‧‧‧ gas transfer device

37‧‧‧Water outlet

52‧‧‧temperature sensor

56‧‧‧ thermostat

62‧‧‧Electric motor

66‧‧‧Magnetic Couplings

72‧‧‧Inflator

74‧‧‧ gas cylinder

Claims (8)

A vacuum oven comprising: a box having a first side wall, a second side wall and a third side wall; a heat insulating outer wall surrounding the box body, having a first side wall, a second side wall and a third side wall; a gas transfer device, And the temperature control device for controlling the temperature inside the box, the vacuum oven further comprising a cooling device disposed between the box and the heat insulating outer wall, the cooling device comprising a cooling water The cooling water jacket of the cooling device has a first interlayer, a second interlayer and a third interlayer connected to the first interlayer, and the two side walls of the first interlayer respectively form a first side wall and a heat insulating outer wall of the box The first side wall is adjacent to each other; the two side walls of the second interlayer are respectively adjacent to the second side wall of the box body and the second side wall of the heat insulating outer wall; the two side walls of the third interlayer are respectively opposite to the third side wall of the box body And a third side wall of the insulated outer wall is adjacent. The vacuum oven of claim 1, wherein the gas transfer device comprises at least one air extracting device and at least one air inflating device. The vacuum oven of claim 2, wherein the inflator and the pumping device are in communication with the tank through a separate air tube. The vacuum oven of claim 1, wherein the temperature control device comprises at least one temperature sensor, at least one heater, a thermostat, and a solid state relay. The vacuum oven of claim 4, wherein the temperature control device is located on the inner surface of the first, second or third side wall of the box, and the heater is located on the outer wall of the heat insulation and the cabinet The area between the thermostat and the solid state relay is located outside the insulated outer wall. The vacuum oven of claim 1, wherein the cooling device further comprises at least one water inlet disposed on the cooling water jacket, and at least two water outlets. The vacuum oven of claim 6, wherein at least one water inlet of the cooling device is located adjacent to the heater in a first interlayer of the cooling water jacket and a second or third interlayer connecting region, the at least one The water outlet is located away from the heater in the communication zone between the first interlayer and the second or third interlayer, and the water inlet is located away from the heater in the first interlayer of the cooling water jacket and the communication zone of the second or third interlayer. The vacuum oven of claim 6, wherein the cooling device is located normally adjacent to the heater at a communication zone between the first interlayer of the cooling water jacket and the second or third interlayer.