PCB solder resist pre-baking oven

Abstract

The utility model discloses a kind of PCB solder mask pre-baking furnace, including rack, conveying device 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 loading frame includes frame body, multiple plug-in slots for fixing circuit board edge are arranged in the frame body, and multiple the plug-in slots are spaced distribution.The PCB solder mask pre-baking furnace provided by the utility model uses large pitch conveying chain for conveying device, can improve the load of conveying device, so circuit board uses loading frame to bear, can improve the double-sided drying effect of line board, reduce double-sided temperature difference.

Description

Technical Field

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

[0002] Solder resist ink for printed circuit boards (PCBs) is typically pre-baked in a tunnel oven. Heating the tunnel oven dries the ink on the PCB surface. Currently, PCB solder resist pre-baking ovens mainly use mesh belt tunnel ovens, where the PCB is conveyed via a mesh belt. During pre-baking, only one side of the PCB is heated, with less heat reaching the surface in contact with the mesh belt. This results in poor drying on both sides, with a temperature difference of 10-15℃. Furthermore, the mesh belt is prone to deformation, making it unsuitable for processing large-size PCBs.

[0003] Therefore, the purpose of this utility model is to provide a PCB solder resist pre-baking oven to solve the above-mentioned technical problems. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a PCB solder resist pre-baking oven. The conveying device adopts a large-pitch conveyor chain, which can increase the load capacity of the conveying device. Therefore, 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 PCB solder resist preheating oven 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; the conveying device passes through opposite sides of the tunnel oven, and the conveying device includes a large-pitch conveyor chain and a chain plate connected to the large-pitch conveyor chain; the loading frame includes a frame body and a plurality of insertion slots disposed on the frame body for fixing the edge of the circuit board, and the plurality of insertion slots are spaced apart.

[0007] Furthermore, the pitch of the large-pitch transmission chain is 50.8 mm.

[0008] Furthermore, the conveying device is a stepping conveyor with a conveying speed of 4.5 min / step.

[0009] Furthermore, the plurality of said insertion slots are spaced apart in the vertical direction.

[0010] Furthermore, the number of the insertion slots is 12-15.

[0011] Furthermore, the circuit board carried by the loading frame is a large-sized circuit board with dimensions of 24"×28".

[0012] Compared with the prior art, the PCB solder resist pre-baking oven provided by this utility model has the following advantages:

[0013] I. The PCB solder resist pre-baking oven 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.

[0014] II. The PCB solder resist pre-baking oven provided by this utility model has a loading frame for carrying circuit boards that includes multiple insertion slots for fixing the edges of the circuit boards. In other words, one loading frame can carry multiple circuit boards at the same time, which improves the drying efficiency of the PCB solder resist pre-baking oven.

[0015] Third, the PCB solder resist pre-baking oven provided by this utility model has the circuit board supported by the loading frame, so it can be used for the processing of large-size circuit boards, avoiding the problem of mesh belt deformation caused by the use of mesh belt conveyor belt to support large-size circuit boards in the prior art. Attached Figure Description

[0016] 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.

[0017] Figure 1 This is a schematic diagram of the PCB solder resist pre-baking oven of this utility model;

[0018] Figure 2 yes Figure 1 The diagram shows a structural schematic of the PCB solder mask preheating oven from another angle.

[0019] Figure 3 yes Figure 1 A magnified structural diagram of part A in the diagram;

[0020] Figure 4 yes Figure 1 The diagram shown is a structural schematic of the PCB solder mask pre-baking oven.

[0021] Figure 5 yes Figure 1 The diagram shows the structure of the loading frame in the PCB solder resist preheating oven. Detailed Implementation

[0022] 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.

[0023] 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.

[0024] Please refer to the following: Figure 1 and Figure 2 ,in Figure 1 This is a schematic diagram of the PCB solder mask pre-baking oven of this utility model. Figure 2 yes Figure 1 The diagram shows a structural schematic of the PCB solder resist pre-baking oven from another angle. The PCB solder resist pre-baking oven 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.

[0025] 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.

[0026] In this embodiment, the conveying device 2 is a stepper conveyor driven by a stepper motor at a speed of 4.5 min / step, meaning each step takes 4.5 min. 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.

[0027] The tunnel oven 3 includes an oven body 31, a sealing door 33 disposed within the oven body 31 to divide it into multiple independent baking chambers 32, a drive device (not shown) for driving the sealing door 33 to open or close, a heating device 34 disposed in each independent baking chamber 32, and a circulating fan 35 disposed corresponding to each independent baking chamber.

[0028] Please refer to the following: Figure 4 ,yes Figure 1The diagram shows the structural structure of the furnace body in a tunnel-type weld resistance pre-baking oven. 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.

[0029] In this embodiment, the drive device for opening or closing the sealing door is pneumatic or hydraulic; that is, the sealing door is either pneumatic or hydraulic. Driven by the drive device, the opening and closing time of the 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 also reduces heat loss within the independent baking chambers.

[0030] 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 double-sided temperature uniformity 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.

[0031] 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. 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.

[0032] Please refer to the following: Figure 5 ,yes Figure 1 The diagram shows the structure of the loading frame in the PCB solder mask pre-baking oven. The loading frame 4 includes a frame body 41 and multiple insertion slots 42 disposed 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 disposed 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 in the tunnel oven dries both sides of the circuit board.

[0033] 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.

[0034] 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".

[0035] The PCB solder resist pre-baking oven of this invention has the following technical advantages compared with existing pre-baking ovens:

[0036] Energy consumption (kW) ≥200 ＜150 Furnace temperature uniformity ±5℃ ±2℃ Circuit board double-sided temperature difference 10-15℃ ≤3℃ Maximum board size 18"×24" 24"×28"

[0037] The PCB solder resist pre-baking oven 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, resulting in good drying effect on both sides and reducing the temperature difference between the two sides. 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 processing large-size circuit boards.

[0038] 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 PCB solder resist pre-baking oven, characterized in that, The device 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 loading frame includes a frame body and a plurality of insertion slots disposed on the frame body for fixing the edge of the circuit board, and the plurality of insertion slots are spaced apart.

2. The PCB solder resist pre-baking oven according to claim 1, characterized in that, The pitch of the large-pitch conveyor chain is 50.8 mm.

3. The PCB solder resist pre-baking oven according to claim 2, characterized in that, The conveying device is a stepping conveyor with a conveying speed of 4.5 min / step.

4. The PCB solder resist pre-baking oven according to claim 1, characterized in that, The plurality of the insertion slots are spaced apart in the vertical direction.

5. The PCB solder resist pre-baking oven according to claim 4, characterized in that, The number of the insertion slots is 12-15.

6. The PCB solder resist pre-baking oven according to any one of claims 1-5, characterized in that, The circuit board carried by the loading frame is a large-sized circuit board with dimensions of 24"×28".

Images