Tin explosion prevention structure of PCB (Printed Circuit Board)

Abstract

The utility model discloses a tin explosion prevention structure of a PCB, which comprises the PCB, a copper foil layer is arranged on one side of the PCB, a fixing plate is arranged on the other side of the PCB, a DIP plug-in is arranged on one side of the fixing plate back to the PCB, the DIP plug-in is provided with a pin, the pin penetrates through the fixing plate and penetrates out of one side of the fixing plate towards the PCB, the PCB is provided with a plug-in bonding pad hole and a ventilation structure, and the plug-in bonding pad hole and the ventilation structure penetrate through the PCB. The fixing plate is provided with a ventilation structure, the fixing plate is provided with a ventilation structure penetrating through the fixing plate, the pins are inserted into the plug-in pad holes, plug-in pads are formed around the plug-in pad holes on the sides, penetrating out of the plug-in pad holes, of the pins through welding, and the ventilation structure is communicated with the ventilation structure. According to the utility model, the air dispersing structure on the fixed plate is communicated with the ventilation structure on the PCB, so that hot air generated when the PCB is subjected to wave soldering is transferred to the air above the PCB to be dispersed, and the problem of frequent tin explosion when the plug-in pad is subjected to wave soldering is reduced or eliminated.

Description

Technical Field

[0001] The utility model belongs to the technical field of PCB boards, in particular to an explosion-proof tin structure of a PCB board. Background Art

[0002] PCBA finished products are usually processed and manufactured according to the following steps: one is the early PCB design stage: the other is the later PCBA processing and production stage. The early PCB design stage is divided into: electrical schematic design, PCB package production, PCB layout and wiring, PCB processing file output and board making, etc. The later PCBA processing and production stage is divided into: IQC incoming material inspection, SMT patch process, DIP plug-in furnace process, etc. DIP plug-in refers to components that cannot be mounted by machine and need to be manually plug-in. DIP plug-ins are often assembled on PCB boards, and pads are set on the PCB board corresponding to the DIP plug-in position, and then soldering is performed to make the DIP plug-in firmly fixed on the PCB board. When the DIP plug-in pads are wave soldered, tin frying often occurs, resulting in poor tinning. In order to solve the problem of tin frying that often occurs when the plug-in pads are wave soldered, the following methods are usually adopted:

[0003] 1. By changing the wave soldering method of the DIP plug-in pad, for the SMD device with a protruding surface at the bottom of the PCB board, and when the SMD device is close to the DIP plug-in pad, the direction with no device or relatively few devices at the bottom of the DIP plug-in pad is usually selected as the wave soldering direction. When there is no SMD device at the bottom of the DIP plug-in pad, there is no need to use a fixture to wrap the SMD device, so there is enough space at the bottom of the DIP plug-in pad for tin spraying and wave soldering.

[0004] 2. By changing the furnace temperature environment of DIP. Usually the speed of the furnace is 1100~1300mm / min, the furnace temperature is controlled at 260~285℃, and the preheating temperature is divided into the following stages: 130~140~150℃. If the temperature is lower than the above temperature value, cold soldering is likely to occur during wave soldering; if the temperature is higher than the above temperature value, it is easy to melt the impurities of other components inside the PCB into gas, and the gas volume will remain inside the PCB and cannot be released, increasing the temperature of the PCB and the probability of tin explosion.

[0005] Even by changing the above parameter values ​​and the method of passing the furnace, it is difficult to eliminate the problem of tin frying that often occurs when the DIP plug-in pads are subjected to wave soldering. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a tin explosion prevention structure for a PCB board, which can reduce or eliminate the problem of tin explosion that often occurs on plug-in pads during wave soldering.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A tin explosion-proof structure for a PCB board comprises a PCB board, wherein a copper foil layer is provided on one side of the PCB board, a fixing plate is provided on the other side of the PCB board, a DIP plug-in is provided on the side of the fixing plate facing away from the PCB board, the DIP plug-in has pins, the pins pass through the fixing plate and pass out from the fixing plate toward the side of the PCB board, a plug-in pad hole and a venting structure are provided on the PCB board, an air dispersion structure is provided on the fixing plate passing through the fixing plate, the pins are inserted into the plug-in pad hole, and the plug-in pad is formed by welding around the plug-in pad hole on the side where the pin passes out of the plug-in pad hole, and the air dispersion structure is communicated with the venting structure.

[0009] As a further improved solution, the air permeable structure is an air permeable groove and / or an air permeable hole, and the air diffusion structure is an air diffusion groove and / or an air diffusion hole corresponding to the air permeable structure.

[0010] As a further improved solution, the DIP plug-in includes a magnetic ring, a winding wire is provided on the magnetic ring, and the pins are connected to the winding wire.

[0011] As a further improved solution, the width of the air diffusion groove is 0.6-1.0 mm, and the diameter of the air diffusion hole is 0.6-1.0 mm.

[0012] As a further improved solution, the number of the air diffusing structures and the air permeable structures is kept consistent, and the air diffusing structures and the air permeable structures are distributed in a one-to-one correspondence.

[0013] As a further improved solution, the air diffusion structure is arranged in the area beside the pin.

[0014] As a further improved solution, when the air diffusion structure is an air diffusion groove, the air diffusion groove is a straight line, or the air diffusion groove is a bent shape.

[0015] As a further improved solution, the fixing plate is in contact with the surface of the PCB.

[0016] As a further improved solution, the magnetic ring is circular in shape, and the winding wire is arranged around the circumference of the magnetic ring.

[0017] As a further improved solution, the fixing plate is made of insulating material.

[0018] Compared with the prior art, the utility model has the following beneficial technical effects:

[0019] An air dispersion structure is provided on the fixed plate, and an air permeable structure is provided on the PCB board. The air dispersion structure and the air permeable structure are interconnected. The pins of the DIP plug-in are welded to the PCB board to form a plug-in pad. When the PCB board undergoes wave soldering, the hot air generated at the bottom enters the air dispersion structure through the air permeable structure, and then is transferred to the air above the PCB board to disperse, thereby reducing or eliminating the problem of tin frying that often occurs on the plug-in pad during wave soldering, thereby improving the processing quality, improving the yield rate of the product, and reducing the loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the top view structure of the utility model;

[0021] Figure 2 It is a schematic diagram of the cross-sectional structure of the utility model.

[0022] Figure 3 This is a schematic diagram of the main structure of the fixed plate of the utility model;

[0023] Figure 4 for Figure 3 A side view schematic diagram of

[0024] Figure 5 It is a bottom view schematic diagram of the first embodiment of the fixing plate;

[0025] Figure 6 It is a bottom view schematic diagram of the second embodiment of the fixing plate;

[0026] Figure 7 It is a bottom view schematic diagram of the third embodiment of the fixing plate.

[0027] Reference numerals:

[0028] PCB board 1, plug-in pad hole 11, plug-in pad 12, copper foil layer 13, air permeable structure 14, fixing plate 2, pin 21, magnetic ring 22, winding conductor 23, air diffusion groove 24, air diffusion hole 25. DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0030] In the description of the present invention, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like are involved, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] Embodiment 1

[0033] refer to Figure 1-5As shown, a tin explosion-proof structure of a PCB board comprises a PCB board 1, a copper foil layer 13 is provided on one side of the PCB board 1, a fixing plate 2 is provided on the other side of the PCB board 1, a DIP plug-in is provided on the side of the fixing plate 2 facing away from the PCB board 1, the DIP plug-in has a pin 21, a plug-in pad hole 11 and a venting structure 14 are provided on the PCB board that penetrate the PCB board 1, a diffuser structure that penetrates the fixing plate 2 is provided on the fixing plate 2, the pin 21 of the DIP plug-in is inserted into the plug-in pad hole 11 of the PCB board 1, and a plug-in pad 12 is formed by welding around the plug-in pad hole on the side where the pin 21 passes through the plug-in pad hole 11, and the diffuser structure on the fixing plate 2 is connected with the venting structure 14 on the PCB board 1. The side where the copper foil layer 13 is located is defined as the bottom surface of the PCB board 1, and the other side of the PCB board is defined as the front surface. During assembly, the pin 21 of the DIP plug-in is inserted into the plug-in pad hole 11 from the front of the PCB board 1, and passes through the bottom of the PCB board 1. After welding, the plug-in pad 12 is formed on the bottom of the PCB board 1, and the fixed plate 2 is installed in contact with the front of the PCB board 1. Since the air-permeable structure and the air-dispersing structure are interconnected, when the PCB board assembled with the fixed plate undergoes wave soldering, a large amount of hot air will be generated on the bottom of the PCB board. The hot air enters the air-dispersing structure through the air-permeable structure, and then is transferred to the air above the PCB board to dissipate, so that the hot air at the plug-in pad will not accumulate, and the temperature will be prevented from being too high, thereby reducing or eliminating the problem of tin frying that often occurs on the plug-in pad during wave soldering, improving the quality of the plug-in pad, reducing losses, and improving the yield rate.

[0034] The DIP plug-in comprises a magnetic ring 22 , a winding wire 23 is arranged on the magnetic ring 2 , and the pin 21 is connected to the winding wire 23 .

[0035] The ventilation structure 14 on the PCB board 1 is a ventilation groove and a ventilation hole, the ventilation hole is a circular hole, and the ventilation groove is in a strip shape. The air diffusion structure is an air diffusion groove 24 and an air diffusion hole 25, the air diffusion hole 25 is a circular hole, and the air diffusion groove 24 is in a strip shape. The air diffusion groove is arranged correspondingly to the ventilation groove, and the air diffusion hole is arranged correspondingly to the ventilation hole.

[0036] like Figure 5 As shown, four pins 21 are evenly distributed on the fixing plate 2, and a gas diffusion groove 24 is respectively arranged on the side area of ​​the two pins on the left, and one of the gas diffusion grooves is in a straight line shape, and the other gas diffusion groove is in a bent shape; two circular air holes 25 are respectively arranged on the side area of ​​the two pins on the right; a bent air groove and a straight air groove, as well as four corresponding air holes are arranged on the corresponding area of ​​the PCB board 1 to realize the conduction and dissipation of heat.

[0037] In order to make the structure more compact, the size of the air vent and the air diffuser are kept the same, the size of the air vent and the air diffuser are kept the same, the air diffuser and the air vent are completely opposite and overlapped, and the air diffuser and the air diffuser are completely opposite and overlapped, to ensure the maximum conduction area. When the fixed plate is assembled on the PCB board, the air diffuser is opposite to the air diffuser to maintain conduction, and the air diffuser is opposite to the air vent to maintain conduction. During the welding process of the PCB board, the hot air generated will enter the air vent and the air vent, then enter the air diffuser and the air diffuser, and finally transfer to the area above the fixed plate to dissipate, so that the heat will not accumulate at the plug-in pad, reducing or eliminating the problem of tin frying on the plug-in pad.

[0038] In addition, the width of the air diffusion groove 24 is 0.6-1.0 mm. If the air diffusion groove 24 is a shape with a gradually changing width, the maximum width is limited to between 0.6 and 1.0 mm, and the diameter of the air diffusion hole 25 is 0.6-1.0 mm. The size of the air diffusion groove 24 and the air diffusion hole 25 is numerically limited to avoid being too large or too small. If it is lower than the lower limit of the above limit, the efficiency of hot air passing will be poor, and it is difficult to effectively dissipate hot air; if it is higher than the upper limit of the above limit, it is easy to cause the tin water in the furnace tank to spray onto the surface of the PCB board during wave soldering, affecting the circuit layer on the PCB board.

[0039] The magnetic ring 22 is circular in shape, and the winding conductor 23 is arranged around the circumference of the magnetic ring 22. Multiple turns of the winding conductor are arranged to ensure normal electrical conduction and meet electrical requirements.

[0040] The fixing plate 2 is made of insulating material, such as an insulator formed by polystyrene PS particles, or other types of insulating materials. The melting point of the fixing plate needs to be higher than the hot air temperature of the PCB board during wave soldering to avoid the fixing plate being melted during the soldering process.

[0041] Embodiment 2

[0042] refer to Figure 1-4As shown in Figure 6, a tin explosion-proof structure of a PCB board comprises a PCB board 1, a copper foil layer 13 is provided on one side of the PCB board 1, a fixed plate 2 is provided on the other side of the PCB board 1, a DIP plug-in is provided on the side of the fixed plate 2 facing away from the PCB board 1, the DIP plug-in has a pin 21, a plug-in pad hole 11 and a venting structure 14 are provided on the PCB board that penetrate the PCB board 1, a diffuser structure that penetrates the fixed plate 2 is provided on the fixed plate 2, the pin 21 of the DIP plug-in is inserted into the plug-in pad hole 11 of the PCB board 1, and a plug-in pad 12 is formed by welding around the plug-in pad hole on the side where the pin 21 passes through the plug-in pad hole 11, and the diffuser structure on the fixed plate 2 is connected with the venting structure 14 on the PCB board 1. The side where the copper foil layer 13 is located is defined as the bottom surface of the PCB board 1, and the other side of the PCB board is defined as the front surface. During assembly, the pin 21 of the DIP plug-in is inserted into the plug-in pad hole 11 from the front of the PCB board 1, and passes through the bottom of the PCB board 1. After welding, the plug-in pad 12 is formed on the bottom of the PCB board 1, and the fixed plate 2 is installed in contact with the front of the PCB board 1. The main structure of the second embodiment is the same as that of the first embodiment, except that the specific setting of the air dispersion structure on the fixed plate 2 is different. In the first embodiment, the air dispersion structure is provided with both the air dispersion groove 24 and the air dispersion hole 25; while in the second embodiment, the air dispersion structure is only the air dispersion hole 25, and two air dispersion holes 25 are provided on the side area of ​​each pin 21. The PCB board is also provided with air holes of corresponding number and size. After the fixed plate and the PCB board are assembled, the air dispersion holes and the air dispersion holes are correspondingly overlapped to ensure the smooth circulation of hot air.

[0043] Embodiment 3

[0044] refer to Figure 1-4As shown in Figure 7, a tin explosion-proof structure of a PCB board comprises a PCB board 1, a copper foil layer 13 is provided on one side of the PCB board 1, a fixed plate 2 is provided on the other side of the PCB board 1, a DIP plug-in is provided on the side of the fixed plate 2 facing away from the PCB board 1, the DIP plug-in has a pin 21, a plug-in pad hole 11 and a venting structure 14 are provided on the PCB board that penetrate the PCB board 1, a gas dispersion structure that penetrates the fixed plate 2 is provided on the fixed plate 2, the pin 21 of the DIP plug-in is inserted into the plug-in pad hole 11 of the PCB board 1, and a plug-in pad 12 is formed by welding around the plug-in pad hole on the side where the pin 21 passes through the plug-in pad hole 11, and the gas dispersion structure on the fixed plate 2 is connected with the venting structure 14 on the PCB board 1. The side where the copper foil layer 13 is located is defined as the bottom surface of the PCB board 1, and the other side of the PCB board is defined as the front surface. During assembly, the pin 21 of the DIP plug-in is inserted into the plug-in pad hole 11 from the front of the PCB board 1, and passes through the bottom of the PCB board 1. After welding, the plug-in pad 12 is formed on the bottom of the PCB board 1, and the fixing plate 2 is installed in contact with the front of the PCB board 1. The main structure of the third embodiment is the same as that of the first embodiment, except that the specific setting of the air diffusion structure on the fixing plate 2 is different. In the first embodiment, the air diffusion structure 2 is provided with both the air diffusion groove 24 and the air diffusion hole 25; while in the third embodiment, the air diffusion structure is only the air diffusion groove 24, and one air diffusion groove is provided in the side area of ​​each pin, with a total of four air diffusion grooves, and all of the four air diffusion grooves are in a straight line shape.

[0045] The present application improves the structure so that the fixing plate does not completely cover the PCB board, and forms a structure for hot air circulation in the local area, so that when the PCB board is undergoing wave soldering, the hot air can be dissipated to the area above the PCB board through the breathable structure and the air dispersion structure, and the hot air is discharged in time, thereby reducing or eliminating the problem of hot air accumulation at the plug-in pad causing tin frying of the plug-in pad, thereby improving the product yield during the processing process.

[0046] Prior art comparative example

[0047] A tin explosion-proof structure for a PCB board comprises a PCB board, a copper foil layer is provided on one side of the PCB board, a fixed plate is provided on the other side of the PCB board, a DIP plug-in is provided on the side of the fixed plate facing away from the PCB board, the DIP plug-in has pins, and a gas dispersion structure penetrating the fixed plate is provided on the fixed plate, the pins of the DIP plug-in are inserted into the plug-in pad holes of the PCB board 1, and the plug-in pads are formed by welding around the plug-in pad holes on the side where the pins pass through the plug-in pad holes. During assembly, the pins of the DIP plug-in are inserted into the plug-in pad holes from the front of the PCB board and pass through the bottom of the PCB board. After welding, the plug-in pads are formed on the bottom of the PCB board, and the fixed plate is installed in contact with the front of the PCB board. That is, no gas dispersion structure is provided on the fixed plate. At this time, when the PCB board with the DIP plug-in is subjected to wave soldering, the heat at the bottom of the PCB board will accumulate on the bottom of the PCB board, especially around the pins of the DIP plug-in, resulting in the inability to dissipate the heat in time, the temperature rises, and the problem of explosion occurs, affecting the product quality. It can be seen that the structure of the present application can dissipate the heat in time and effectively, thereby improving the product quality.

[0048] It should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. However, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A tin explosion-proof structure for a PCB board, comprising a PCB board, a copper foil layer being provided on one side of the PCB board, characterized in that: A fixing plate is provided on the other side of the PCB board, a DIP plug-in is provided on the side of the fixing plate facing away from the PCB board, the DIP plug-in has pins, the pins pass through the fixing plate and pass out from the fixing plate toward the side of the PCB board, a plug-in pad hole and a breathable structure passing through the PCB board are provided on the PCB board, an air dispersion structure passing through the fixing plate is provided on the fixing plate, the pins are inserted into the plug-in pad hole, and the plug-in pad is formed by welding around the plug-in pad hole on the side where the pin passes out of the plug-in pad hole, and the air dispersion structure is communicated with the breathable structure.

2. The explosion-proof tin structure of the PCB board according to claim 1, characterized in that: The air permeable structure is an air permeable groove and / or an air permeable hole, and the air diffusion structure is an air diffusion groove and / or an air diffusion hole corresponding to the air permeable structure.

3. The explosion-proof tin structure of a PCB board according to claim 1, characterized in that: The DIP plug-in comprises a magnetic ring, a winding wire is arranged on the magnetic ring, and the pins are connected to the winding wire.

4. The anti-explosion tin structure of the PCB board according to claim 2, characterized in that: The width of the air diffusion groove is 0.6-1.0 mm, and the diameter of the air diffusion hole is 0.6-1.0 mm.

5. The explosion-proof tin structure of a PCB board according to claim 1, characterized in that: The number of the air-diffusing structures and the air-permeable structures is consistent, and the air-diffusing structures and the air-permeable structures are distributed in a one-to-one correspondence.

6. The explosion-proof tin structure of a PCB board according to claim 1, characterized in that: The air diffusion structure is arranged in the area beside the pin.

7. The explosion-proof tin structure of a PCB board according to claim 2, characterized in that: When the air diffusion structure is an air diffusion groove, the air diffusion groove is a straight line type, or the air diffusion groove is a bent type.

8. The explosion-proof tin structure of a PCB board according to claim 1, characterized in that: The fixing plate is in contact with the surface of the PCB.

9. The explosion-proof tin structure of a PCB board according to claim 3, characterized in that: The magnetic ring is circular in shape, and the winding wire is arranged around the circumference of the magnetic ring.

10. The explosion-proof tin structure of a PCB board according to claim 1, characterized in that: The fixing plate is made of insulating material.

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