A pneumatic door tunnel type solder resist pre-baking equipment

Abstract

The utility model discloses a kind of pneumatic door tunnel type solder resist pre-baking equipment, including rack, the conveying device of being located at the rack, support the tunnel furnace of the rack, and support the loading frame on the conveying device;The conveying device passes through the opposite sides of tunnel furnace, the conveying device includes large pitch conveying chain, and the chain plate connected with the large pitch conveying chain;The tunnel furnace includes furnace body, is located in the pneumatic sealing door of furnace body and is separated to form multiple independent baking bin, heating device is located in each independent baking bin, and the circulating fan corresponding each independent baking bin is arranged;The loading frame includes frame body, multiple plug-in slots for fixing circuit board edge are located in the frame body, and multiple the plug-in slots are interval distribution. The pneumatic door tunnel type solder resist pre-baking equipment provided by the utility model can improve the uniformity of temperature in the furnace, reduce the temperature difference of double-sided circuit board.

Description

Technical Field

[0001] This utility model relates to the technical field of printed circuit board processing equipment, specifically to a pneumatic door tunnel-type solder resist pre-baking equipment. Background Technology

[0002] Solder resist ink for circuit boards is typically pre-baked in a tunnel oven. Heating the tunnel oven dries the ink on the circuit board surface. Current technology usually employs a hot air circulation heating method, where hot air is delivered into the pre-baking oven and circulated to bake and cure the solder resist ink. However, this method uses a circulating fan that heats the entire space within the tunnel oven, resulting in low heating efficiency. Furthermore, the large space requiring heating by the circulating hot air leads to uneven temperature distribution within the oven, with temperature differences ranging from ±5℃. Moreover, current pre-baking ovens primarily use mesh belt tunnel ovens, where the circuit boards are conveyed via a mesh belt. During pre-baking, only one side of the circuit board is heated, with less heat reaching the surface in contact with the conveyor belt. This results in poor drying on both sides, with temperature differences reaching 10-15℃, leading to ineffective ink drying.

[0003] Therefore, the purpose of this utility model is to provide a pneumatic door tunnel-type resist welding preheating equipment to solve the above-mentioned technical problems. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a pneumatic door tunnel-type resist welding pre-baking equipment, which divides the pre-baking oven into multiple independent baking chambers and separates each independent baking chamber by a pneumatic sealing door, thereby improving heating efficiency and ensuring temperature uniformity inside the oven; the conveying device adopts a large-pitch conveyor chain to increase the load capacity of the conveying device, so the circuit board is supported by a loading frame, which can improve the double-sided drying effect of the circuit board and reduce the temperature difference between the two sides.

[0005] The technical solution of this utility model is as follows:

[0006] A pneumatic door tunnel-type resist welding preheating equipment includes a frame, a conveying device disposed on the frame, a tunnel oven supported on the frame, and a loading frame supported on the conveying device.

[0007] The conveying device passes through opposite sides of the tunnel furnace, and the conveying device includes a large-pitch conveying chain and chain plates connected to the large-pitch conveying chain;

[0008] The tunnel oven includes an oven body, a pneumatic sealing door disposed within the oven body to divide it into multiple independent baking chambers, a heating device disposed in each independent baking chamber, and a circulating fan disposed corresponding to each independent baking chamber;

[0009] The loading frame includes a frame body and a plurality of plug slots disposed on the frame body for fixing the edge of the circuit board, wherein the plurality of plug slots are distributed at intervals.

[0010] Furthermore, the conveying device is a stepping conveyor with a transmission speed of 4.5 min / step; the pitch of the large-pitch conveyor chain is 50.8 mm.

[0011] Furthermore, the heating device includes a microwave generator and a ceramic heater.

[0012] Furthermore, the microwave generator operates at a frequency of 2.45 GHz ± 50 MHz, and the ceramic heater has a power of 5-10 kW.

[0013] Furthermore, the circulating fan is a high-temperature resistant circulating fan, the air velocity of the circulating fan is 4-6 m / min, and a filter device is provided on the air inlet pipe of the circulating fan.

[0014] Furthermore, the furnace body is made of stainless steel and has an insulation layer on its surface, with a thickness of 80-120mm.

[0015] Furthermore, the number of independent baking chambers is 8-12.

[0016] Furthermore, the number of insertion slots is 12-15.

[0017] Furthermore, the circuit board carried by the loading frame is a large-sized circuit board with dimensions of 24"×28".

[0018] Furthermore, the tunnel oven also includes a temperature sensor and an alarm installed in each independent baking chamber. When the temperature detected by the temperature sensor exceeds the set value, the alarm will sound.

[0019] Compared with the prior art, the pneumatic door tunnel-type resist welding preheating equipment provided by this utility model has the following advantages:

[0020] I. The pneumatic tunnel-type solder resist pre-baking equipment provided by this utility model uses a large-pitch conveyor chain for transporting circuit boards, which increases the load capacity of the conveyor. Therefore, the circuit boards can be supported by a loading frame, and both sides of the circuit boards can be exposed inside the tunnel oven, resulting in good double-sided drying and reducing the temperature difference between the two sides. The loading frame for supporting the circuit boards includes multiple insertion slots for fixing the edges of the circuit boards, meaning that one loading frame can support multiple circuit boards simultaneously, improving the drying efficiency of the PCB solder resist pre-baking oven. Since the circuit boards are supported by the loading frame, it is suitable for processing large-size circuit boards, avoiding the problem of mesh belt deformation caused by using a mesh belt to support large-size circuit boards in the prior art. This pneumatic tunnel-type solder resist pre-baking equipment is suitable for processing circuit boards with a size of 24"×28".

[0021] II. The pneumatic door tunnel-type solder resist pre-baking equipment provided by this utility model divides the furnace body into multiple independent baking chambers. Each independent baking chamber is equipped with a pneumatic sealing door. When pre-baking the circuit board, each independent baking chamber works independently, which can improve the heat utilization rate of the heating device, thereby improving the heating efficiency and ensuring the temperature uniformity in each independent baking chamber.

[0022] III. The pneumatic tunnel-type solder resist preheating equipment provided by this utility model includes a heating device comprising a microwave generator and a ceramic heater. The combination of the two can improve heating efficiency. The microwave generator can improve heat penetration, reduce the temperature difference between the two sides of the circuit board, and improve the temperature uniformity of the circuit board. Testing shows that the temperature difference between the two sides of the circuit board is ≤3℃.

[0023] IV. The pneumatic door tunnel-type resist welding pre-baking equipment provided by this utility model has a heat insulation layer on the surface of the tunnel furnace body, which can prevent heat loss from the furnace body and further improve heat utilization. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the pneumatic door tunnel-type shielding welding preheating equipment of this utility model;

[0026] Figure 2 yes Figure 1 A schematic diagram of the pneumatic door tunnel-type resist welding preheating equipment from another angle;

[0027] Figure 3 yes Figure 1A magnified structural diagram of part A in the diagram;

[0028] Figure 4 yes Figure 1 The diagram shows the structure of the furnace body in the pneumatic door tunnel-type resist welding pre-baking equipment.

[0029] Figure 5 yes Figure 1 The diagram shows the structure of the loading frame in the pneumatic door tunnel-type resist welding preheating equipment. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solutions in the embodiments of this utility model, and to make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be further described below in conjunction with the accompanying drawings.

[0031] It should be noted that the descriptions of these embodiments are for the purpose of aiding understanding of the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] Please refer to the following: Figure 1 and Figure 2 ,in Figure 1 This is a structural schematic diagram of the pneumatic door tunnel-type resist welding pre-baking equipment of this utility model. Figure 2 yes Figure 1 The diagram shows another angle of the pneumatic door tunnel-type solder resist preheating equipment. The pneumatic door tunnel-type solder resist preheating equipment of this utility model includes a frame 1, a conveying device 2 disposed on the frame 1, a tunnel oven 3 supported on the frame 1, and a loading frame 4 supported on the conveying device. The loading frame 4 is used to carry the circuit board 200.

[0033] Please refer to the following: Figure 3 ,yes Figure 1 The diagram shows an enlarged view of part A. In this invention, the conveying device 2 is a heavy-duty conveying device, which includes a large-pitch conveying chain 21 and chain plates 22 connected to the large-pitch conveying chain. In this embodiment, the pitch of the large-pitch conveying chain is 50.8 mm; the larger the chain pitch, the greater its load-bearing capacity.

[0034] In this embodiment, the conveying device 2 is a stepper conveyor driven by a stepper motor. The stepper motor speed is 4.5 min / step, meaning each step takes 4.5 min. The stepper motor speed is set according to the baking time of the circuit board and the length of the tunnel oven. The stepper conveyor achieves precise positioning and synchronous conveying by intermittently pushing materials or workpieces, and is widely used in automated processes in industrial production. In this embodiment, by using a stepper conveyor, the spacing between two adjacent loading frames can be ensured to be stable, and because the step length is controllable, the uniformity of heating the circuit board can be guaranteed.

[0035] The tunnel oven 3 includes an oven body 31, a pneumatic sealing door 33 disposed within the oven body 31 to divide it into multiple independent baking chambers 32, a heating device 34 disposed in each independent baking chamber 32, and a circulating fan 35 disposed corresponding to each independent baking chamber.

[0036] Please refer to the following: Figure 4 ,yes Figure 1 The diagram shows the structural structure of the furnace body in the pneumatic tunnel-type resist welding preheating equipment. In this invention, the furnace body 31 is made of stainless steel, and its surface has a heat insulation layer 311. Specifically, the heat insulation layer is a rock wool insulation layer with a thickness of 80-120mm. The heat insulation layer 311 prevents heat loss from the furnace body and improves heat utilization. The heat insulation layer 311 can be located on the outer wall or the inner wall of the furnace body 31.

[0037] In this embodiment, the opening and closing time of the pneumatic sealing door is less than 1 second, allowing the circuit board to smoothly move from one independent baking chamber to the next during the pre-baking process. The sealing door reduces heat loss within the independent baking chambers. In this embodiment, the pneumatic sealing door divides the oven into 8-12 independent baking chambers. For example, when there are 10 independent baking chambers and the circuit board baking time is 45 minutes, the stepper motor speed of the conveyor is 4.5 minutes per step. In this embodiment, each independent baking chamber 10 contains two loading frames 4.

[0038] In this embodiment, the heating device 34 includes a microwave generator 341 and a ceramic heater 342. The microwave generator operates at a frequency of 2.45 GHz ± 50 MHz, and the ceramic heater 342 has a power of 5-10 kW. The combination of microwave generator heating and ceramic heater heating improves heating efficiency. Furthermore, the microwave generator has penetrating heating properties, which further improves the temperature uniformity within the independent baking chamber and the temperature uniformity on both sides of the circuit board, thereby reducing the temperature difference between the two sides of the circuit board. Specifically, the microwave generator 341 and the ceramic heater 342 are installed on the side wall of the oven body.

[0039] Each independent baking chamber is equipped with a corresponding circulating fan 35, allowing heat to circulate independently within the chamber. The circulating hot air creates an internal circulation of the heat generated by the heating device within the independent baking chamber, improving heating efficiency. In this embodiment, the circulating fan 35 is a high-temperature resistant circulating fan with a power of 1.2-1.8KW and a wind speed of 4-6 m / min. Preferably, the air inlet pipe of the circulating fan 35 is equipped with a filter device 36 to filter the circulating hot air, removing impurities and preventing contamination of the circuit board.

[0040] In this utility model, the tunnel oven 3 also includes a temperature sensor 37 and an alarm 38 installed in each independent baking chamber. The alarm is installed on the top of the oven body. The temperature sensor 37 and the alarm 38 are electrically connected to the control system. The temperature sensor 37 sends the detection data to the control system. When the temperature detected by the temperature sensor exceeds the set value, the control system controls the alarm 38 to sound an alarm.

[0041] Please refer to the following: Figure 5 ,yes Figure 1 The diagram shows the structure of the loading frame in the pneumatic tunnel-type solder resist pre-baking equipment. The loading frame 4 includes a frame body 41 and multiple insertion slots 42 located on the frame body for fixing the edges of the circuit board. Specifically, the frame body 41 includes a bottom support 411, multiple columns 412 located on the bottom support 411, and a top support 413 connected to the top of the columns 412. The inner sides of two opposing columns are respectively provided with symmetrically distributed insertion slots 42. When placing the circuit board, the opposite sides of the circuit board 200 are embedded in the insertion slots, while the surface of the circuit board is exposed. The hot air inside the tunnel oven dries both sides of the circuit board.

[0042] In this embodiment, the multiple connector slots 42 are spaced apart in the vertical direction, so that the circuit board is placed horizontally. Alternatively, the multiple connector slots can be spaced apart in the horizontal direction, in which case the surface of the circuit board is perpendicular to the horizontal direction.

[0043] In this embodiment, the number of insertion slots 42 is 12-15, meaning each loading frame can hold 12-15 circuit boards, improving the drying efficiency of the PCB solder mask pre-baking oven. Since the circuit boards are carried by the loading frames, it is suitable for processing large-size circuit boards, avoiding the problem of conveyor belt deformation that occurs when using a mesh conveyor belt to carry large-size circuit boards in the prior art. In this embodiment, the circuit boards carried by the loading frames are large-size circuit boards with dimensions of 24" × 28".

[0044] This utility model discloses a pneumatic door tunnel-type resist welding pre-baking equipment with a baking temperature of 75℃. Compared with existing pre-baking ovens, its technical advantages are as follows:

[0045]

[0046] The pneumatic door tunnel-type solder resist pre-baking equipment provided by this utility model uses a large-pitch conveyor chain for conveying circuit boards, which can increase the load capacity of the conveyor. Therefore, the circuit boards can be supported by a loading frame, and both sides of the circuit boards can be exposed in the tunnel oven. The double-sided drying effect of the circuit boards is good, and the temperature difference between the two sides is reduced. The loading frame can support multiple circuit boards at the same time, which improves the drying efficiency of the PCB solder resist pre-baking oven and can be used for the processing of large-size circuit boards.

[0047] The pneumatic door tunnel-type solder resist pre-baking equipment provided by this utility model has a furnace body divided into multiple independent baking chambers. Each independent baking chamber is equipped with a pneumatic sealing door. When pre-baking the circuit board, each independent baking chamber works independently, which can improve the heat utilization rate of the heating device, thereby improving the heating efficiency and ensuring the temperature uniformity in each independent baking chamber.

[0048] The embodiments of this utility model have been described in detail above with reference to the accompanying drawings, but this utility model is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and spirit of this utility model still fall within the protection scope of this utility model.

Claims

1. A pneumatic tunnel-type resist welding pre-baking equipment, characterized in that, It includes a frame, a conveying device disposed on the frame, a tunnel furnace supported on the frame, and a loading frame supported on the conveying device; The conveying device passes through opposite sides of the tunnel furnace, and the conveying device includes a large-pitch conveying chain and chain plates connected to the large-pitch conveying chain; The tunnel oven includes an oven body, a pneumatic sealing door disposed within the oven body to divide it into multiple independent baking chambers, a heating device disposed in each independent baking chamber, and a circulating fan disposed corresponding to each independent baking chamber; The loading frame includes a frame body and a plurality of plug slots disposed on the frame body for fixing the edge of the circuit board, wherein the plurality of plug slots are distributed at intervals.

2. The pneumatic door tunnel-type resist welding pre-baking equipment according to claim 1, characterized in that, The conveying device is a stepping conveyor with a transmission speed of 4.5 min / step; the pitch of the large-pitch conveyor chain is 50.8 mm.

3. The pneumatic door tunnel-type resist welding pre-baking equipment according to claim 1, characterized in that, The heating device includes a microwave generator and a ceramic heater.

4. The pneumatic door tunnel-type resist welding pre-baking equipment according to claim 3, characterized in that, The microwave generator operates at a frequency of 2.45 GHz ± 50 MHz, and the ceramic heater has a power of 5-10 kW.

5. The pneumatic door tunnel-type resist welding pre-baking equipment according to claim 1, characterized in that, The circulating fan is a high-temperature resistant circulating fan with a wind speed of 4-6 m / min and a filter device is installed on the air inlet pipe of the circulating fan.

6. The pneumatic door tunnel-type resist welding pre-baking equipment according to claim 1, characterized in that, The furnace body is made of stainless steel and has an insulation layer on its surface with a thickness of 80-120mm.

7. The pneumatic door tunnel-type resist welding preheating equipment according to claim 1, characterized in that, The number of independent baking chambers is 8-12.

8. The pneumatic door tunnel-type resist welding pre-baking equipment according to claim 1, characterized in that, The number of connector slots is 12-15.

9. The pneumatic door tunnel-type resist welding preheating equipment according to claim 1, characterized in that, The circuit board carried by the loading frame is a large-sized circuit board with dimensions of 24"×28".

10. The pneumatic door tunnel-type resist welding preheating equipment according to any one of claims 1-9, characterized in that, The tunnel oven also includes temperature sensors and alarms installed in each independent baking chamber. When the temperature detected by the temperature sensor exceeds the set value, the alarm will sound.

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