Backflow heat absorption cover device of complex circuit board assembly and reflow soldering method

Abstract

The invention provides a backflow heat absorption cover device of a complex circuit board assembly and a reflow soldering method, the device comprises an upper cover plate and a reflow carrier, a supporting frame is fixedly installed on the periphery of the upper cover plate, a plurality of hot air inlet grooves are formed in the supporting frame, a plurality of heating holes are formed in the upper cover plate, and the heating holes are communicated with the reflow carrier. A plurality of spring pressing blocks are fixedly installed in the upper cover plate, the backflow carrier is provided with a circuit board supporting groove, the upper cover plate is detachably connected with the backflow carrier through a plurality of spring fixing buckles, and a complex circuit board is placed in a containing space between the upper cover plate and the backflow carrier. And welding the complex circuit board assembly by using a reflow soldering process. In this way, imbalance of the heat source and the temperature is avoided, and the assembly welding success rate and the assembly quality are improved; the spring pressing block is used for physical positioning, and warping of the circuit board and welding failure of the assembly and the circuit board are avoided.

Description

Technical Field

[0001] The embodiments of the present invention generally relate to the technical field of circuit board welding, and more particularly to a reflow heat absorbing cover device and a reflow soldering method for a complex circuit board assembly. Background Art

[0002] With the development of science and technology, the demand for the functional integration of electronic products has increased, and many complex circuit board assemblies have appeared on the market. As the name implies, complex circuit board assemblies have complex circuit board designs, and their components integrate different package sizes on the market. Therefore, the size of the circuit board itself is generally large. Using conventional reflow soldering processes on complex circuit boards will cause the following problems with the heat absorption of the circuit board and its components: 1. The circuit board will expand and contract when heated and cooled. If the expansion and contraction cannot be simultaneous, it will cause different stresses and deformation. At this time, if the temperature of the circuit board has reached the upper limit of the temperature resistance value, it will begin to soften, causing permanent deformation. Based on this principle, the larger the size of the circuit board, the greater the deformation of the circuit board. At the same time, the deformation of the circuit board will be accompanied by the problem of component and circuit board welding failure; 2. The uneven temperature of the circuit board assembly causes the temperature of the component with small required heat capacity to exceed the heat resistance value, further causing the component function to fail. Summary of the invention

[0003] To solve the above problems, the present invention uses a reflow heat absorbing cover to evenly transfer high-temperature heat waves into the component welding position, avoiding the imbalance of heat source and temperature, achieving temperature balance and stability of the component, thereby improving the component welding success rate and component quality; the heat absorbing cover adopts a spring pressure block method for physical positioning, avoiding the occurrence of circuit board warping and component and circuit board welding failure.

[0004] According to an embodiment of the present invention, a reflow heat absorbing cover device and a reflow soldering method for a complex circuit board assembly are provided.

[0005] In a first aspect of the present invention, a reflow heat absorption cover device for a complex circuit board assembly is provided. The device comprises: an upper cover plate and a reflow carrier, a support frame is fixedly installed around the upper cover plate, a plurality of hot air inlet slots are provided on the support frame, a plurality of heating holes are provided on the upper cover plate, a plurality of spring pressure blocks are fixedly installed inside the upper cover plate, the reflow carrier is provided with a circuit board support slot, and the upper cover plate is detachably connected to the reflow carrier through a plurality of spring fixing buckles.

[0006] Furthermore, the upper cover plate and the supporting frame are fixed by screws, and the supporting frame has a height of 6 mm to 10 mm and a width of 2 mm to 6 mm.

[0007] Furthermore, the number and positions of the heating holes are customized according to the welding temperature of each component on the circuit board, and the heating holes are located above the components whose required heat capacity is greater than the temperature of the hot air entering the hot air inlet slot.

[0008] Furthermore, the interior of the upper cover plate is designed to have a stepped thickness of 2 mm to 6 mm according to the size and layout of the circuit board assembly, and opening barrier strips are provided around the heating hole.

[0009] Furthermore, the spring fixing buckle includes: a second spring, a fixing rod and two rectangular fixing blocks, the upper cover plate is provided with a plurality of through holes, the fixing rod passes through the through holes, the fixing blocks are fixed to the two ends of the fixing rod, the second spring is arranged on the fixing rod, the second spring is located on the outer side of the upper cover plate, the diameter of the second spring is larger than the diameter of the through hole, the diameter of the fixing rod is smaller than the diameter of the through hole, and the reflux carrier is provided with a plurality of buckle fixing holes, the buckle fixing holes are rectangular through holes with a length of 1mm to 10mm, a width of 1mm to 5mm, and a thickness of 0.5mm to 5mm.

[0010] Furthermore, the spring pressure block includes: a first spring, a telescopic rod and two pressure blocks, the first spring is arranged on the telescopic rod, one pressure block is fixed at each end of the telescopic rod, and the pressure block at either end of the first spring pressure block is fixedly installed in the upper cover plate.

[0011] Furthermore, the upper cover plate and the supporting frame are made of high temperature resistant materials, including: synthetic stone, stainless steel, and titanium alloy.

[0012] Furthermore, a plurality of positioning pins are embedded on the support frame, each positioning pin is in the shape of a cone with a diameter of 1mm to 3mm, and the tip of the positioning pin is embedded downward on the support frame. Positions corresponding to the positioning pins on the reflow carrier are also provided with positioning pin holes, and the diameter of the positioning pin holes is 0.5mm to 3mm.

[0013] Furthermore, the expansion coefficient of the material of the positioning tip is greater than the expansion coefficient of the material of the supporting frame.

[0014] Furthermore, the size of the circuit board support groove is 0.2mm to 2mm larger than the size of the circuit board and is sunken by 0.5mm to 5mm.

[0015] In a second aspect of the present invention, a reflow soldering method for a complex circuit board assembly is provided. The method comprises: placing a complex circuit board in a receiving space between an upper cover plate of the device described in the first aspect and a reflow carrier, and soldering the complex circuit board assembly in the reflow heat absorbing cover device of the complex circuit board assembly using a hot air reflow soldering process.

[0016] The present invention uses a reflow heat absorbing cover to evenly transfer high-temperature heat waves deep into the component welding position, thereby avoiding the imbalance of heat source and temperature, achieving temperature balance and stability of the component, and thus improving the component welding success rate and component quality; the heat absorbing cover adopts a spring pressure block method for physical positioning, thereby avoiding the occurrence of circuit board warping and component and circuit board welding failure.

[0017] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other features, advantages and aspects of the embodiments of the present invention will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings.

[0019] Figure 1 A schematic structural diagram of a reflow heat absorbing cover device of a complex circuit board assembly according to an embodiment of the present invention is shown;

[0020] Figure 2 A schematic diagram of the upper cover structure of a reflow heat absorption cover device of a complex circuit board assembly according to an embodiment of the present invention is shown;

[0021] Figure 3 A schematic diagram of the structure of a reflow carrier of a reflow heat absorbing cover device of a complex circuit board assembly according to an embodiment of the present invention is shown;

[0022] Figure 4 A schematic diagram of the structure of a spring pressure block of a reflow heat absorption cover device of a complex circuit board assembly according to an embodiment of the present invention is shown;

[0023] Figure 5 A schematic diagram of a spring fixing buckle structure of a reflow heat absorbing cover device of a complex circuit board assembly according to an embodiment of the present invention is shown;

[0024] Figure 6 A schematic structural diagram of a reflow heat absorption cover device for a complex circuit board assembly according to Embodiment 2 of the present invention is shown.

[0025] Numbers in the figure: 1. Upper cover; 2. Reflow carrier; 3. Support frame; 4. Hot air inlet slot; 5. Heating hole; 6. Opening barrier strip; 7. Spring pressure block; 8. First spring; 9. Telescopic rod; 10. Pressure block; 11. Circuit board support slot; 12. Spring fixing buckle; 13. Fixing rod; 14. Fixing block; 15. Second spring; 16. Through hole; 17. Buckle fixing hole; 18. Positioning pin; 19. Positioning pin hole; 20. Circuit board. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] According to an embodiment of the present invention, a reflow heat absorbing hood device and a reflow soldering method for a complex circuit board assembly are proposed. The reflow heat absorbing hood is used to evenly transfer high-temperature heat waves into the assembly welding position, thereby avoiding the imbalance of heat source and temperature, achieving temperature balance and stability of the assembly, and thus improving the assembly welding success rate and assembly quality. The heat absorbing hood is physically positioned by a spring pressure block, thereby avoiding the occurrence of circuit board warping and component and circuit board welding failure.

[0028] The following three specific examples further illustrate the reflow heat absorbing cover device of complex circuit board components in more detail:

[0029] Embodiment 1:

[0030] like Figure 1-Figure 3 As shown, the reflow heat absorption cover device of the complex circuit board assembly includes: an upper cover plate 1 and a reflow carrier 2, and the upper cover plate 1 and the supporting frame 3 are made of synthetic stone.

[0031] The interior of the upper cover plate 1 is designed with a stepped thickness of 2mm and 6mm according to the size and layout of the circuit board 20 components, which can balance the temperature of components of different sizes and reduce the damage to the components caused by temperature shock. The upper cover plate 1 is fixed with a support frame 3 by screws on all sides. The support frame 3 has a height of 6mm and a width of 2mm, so as to support the upper cover plate 1 to avoid the highest component height and avoid contact between the upper cover plate 1 and the components causing component displacement; each side of the support frame 3 is provided with 5 hot air inlet slots 4 to achieve the introduction of hot air to heat the circuit board 20 components as a whole.

[0032] Two positioning pins 18 are embedded on the support frame 3. The positioning pins 18 are in the shape of a cone with an upper diameter of 2mm and a lower diameter of 1mm. The tip of the positioning pins 18 is embedded downward on the support frame 3. A positioning pin hole 19 is also provided at a position corresponding to the positioning pins 18 on the reflow carrier 2. The diameter of the positioning pin hole 19 is 2mm. The expansion coefficient of the material of the positioning pins 18 is greater than the expansion coefficient of the material of the support frame 3. This embodiment adopts stainless steel material. Since the body of the reflow heat absorption cover is made of synthetic stone, its thermal expansion coefficient is generally 13 (unit: 10-6 / K). In actual use, it is found that if the thermal expansion coefficient of the positioning pin is smaller than that of the synthetic stone, the positioning pin will fall off easily. The expansion coefficient of stainless steel is generally 14.4~16 (unit: 10-6 / K), and its expansion coefficient is greater than that of the synthetic stone material, which effectively avoids the problem of the positioning pin falling off easily.

[0033] A heating hole 5 is provided on the upper cover plate 1, and the heating hole 5 is located above a component whose required heat capacity is greater than the temperature of the hot air entering the hot air inlet slot 4. Open-hole barrier strips 6 are provided around the heating hole 5. The hot air directly heats the large component through the heating hole 5, and at the same time, the open-hole barrier strips 6 prevent the hot air from directly heating the surrounding small-sized components, thereby preventing the small components from being damaged due to excessive temperature.

[0034] Four spring pressure blocks 7 are fixedly installed inside the upper cover plate 1 at a position where the thickness of the upper cover plate 1 is 2 mm, and the spring pressure blocks 7 avoid all components and abut against the current plate 20. Figure 4 As shown, the spring pressure block 7 includes: a first spring 8 with a natural length of 12 mm and an inner diameter of 1.5 mm, a telescopic rod 9 with an overall length of 10 mm and a telescopic stroke of 3 mm, and two pressure blocks 10 with a length of 3 mm, a width of 2 mm, and a thickness of 2 mm. The first spring 8 is arranged on the telescopic rod 9, and one pressure block 10 is fixed at each end of the telescopic rod 9. The pressure block 10 at either end of the spring pressure block 7 is fixedly installed in the upper cover plate 1. The circuit board 20 is fixed flat on the carrier by the elastic force of the first spring 8, thereby solving the deformation problem of the circuit board 20.

[0035] The reflow carrier 2 is provided with a circuit board supporting groove 11 , the size of which is 0.2 mm larger than the size of the circuit board 20 and is sunken 0.5 mm, so as to avoid the problem of the circuit board 20 being difficult to take out in actual operation due to thermal expansion and contraction.

[0036] The upper cover plate 1 is detachably connected to the reflow carrier 2 via four spring fixing buckles 12. Figure 5As shown, the spring fixing buckle 12 includes: a second spring 15 with a natural length of 3mm and an outer diameter of 0.8mm, a fixing rod 13 with a length of 20mm and a diameter of 0.5mm, and two fixing blocks 14 with a length of 1.5mm, a width of 1mm, and a thickness of 0.5mm. The upper cover plate 1 is provided with four through holes 16 with a diameter of 0.6mm, the fixing blocks 13 pass through the through holes 16, the fixing blocks 14 are fixed to both ends of the fixing rod 13, the second spring 15 is arranged on the fixing rod 13, and the second spring 15 is located on the outer side of the upper cover plate. A buckle fixing hole 17 is provided on the reflux carrier 2 at a position corresponding to the spring fixing buckle 12. The length of the buckle fixing hole 17 is 1.7 mm and the width is 1.2 mm. By pressing the fixing block 14 on the outer side of the upper cover plate 1, the fixing block 14 at the other end is driven downward to pass through the buckle fixing hole 17 and then the spring fixing buckle is rotated so that the long side of the fixing block 14 is perpendicular to the long side of the buckle fixing hole 17. The upper cover plate 1 and the reflux carrier 2 are fixed by the elastic force of the second spring 15, which is convenient for actual operation.

[0037] Embodiment 2:

[0038] like Figure 2 , Figure 3 as well as Figure 6 As shown, the reflow heat absorption cover device of the complex circuit board assembly includes: an upper cover plate 1 and a reflow carrier 2, and the upper cover plate 1 and the supporting frame 3 are made of synthetic stone.

[0039] The interior of the upper cover plate 1 is designed with stepped thicknesses of 2mm, 2.5mm, 4mm and 6mm according to the size and layout of the circuit board 20 components, which can balance the temperature of components of different sizes and reduce the damage to the components caused by temperature shock. The upper cover plate 1 is fixed with support frames 3 by screws on all sides. The support frames 3 are 10mm high and 6mm wide, so as to support the upper cover plate 1 to avoid the highest component height and avoid contact between the upper cover plate 1 and the components causing component displacement; each side of the support frame 3 is provided with 5 hot air inlet slots 4 to achieve the introduction of hot air to heat the circuit board 20 components as a whole.

[0040] Two positioning pins 18 are embedded on the support frame 3. The positioning pins 18 are in the shape of a cone with an upper diameter of 3mm and a lower diameter of 1mm. The tip of the positioning pins 18 is embedded downward on the support frame 3. A positioning pin hole 19 is also provided at a position corresponding to the positioning pins 18 on the reflow carrier 2. The diameter of the positioning pin hole 19 is 3mm. The expansion coefficient of the material of the positioning pins 18 is greater than the expansion coefficient of the material of the support frame 3. This embodiment adopts stainless steel material. Since the body of the reflow heat absorption cover is made of synthetic stone, its thermal expansion coefficient is generally 13 (unit: 10-6 / K). In actual use, it is found that if the thermal expansion coefficient of the positioning pin is smaller than that of the synthetic stone, the positioning pin will fall off easily. The expansion coefficient of stainless steel is generally 14.4~16 (unit: 10-6 / K), and its expansion coefficient is greater than that of synthetic stone, which effectively avoids the problem of the positioning pin falling off easily.

[0041] Five heating holes 5 are provided on the upper cover plate 1, and the heating holes 5 are located above the components whose required heat capacity is greater than the temperature of the hot air entering the hot air inlet slot 4. Open-hole barrier strips 6 are provided around the heating holes 5. The hot air directly heats the large components through the heating holes 5, and at the same time, the open-hole barrier strips 6 prevent the hot air from directly heating the surrounding small-sized components, thereby avoiding damage to the small components due to excessive temperature.

[0042] Four spring pressure blocks 7 are fixedly installed inside the upper cover plate 1 at a position where the thickness of the upper cover plate 1 is 4 mm, and the spring pressure blocks 7 avoid all components and abut against the current plate 20. Figure 4 As shown, the spring pressure block 7 includes: a first spring 8 with a natural length of 14 mm and an inner diameter of 2.5 mm, a telescopic rod 9 with an overall length of 12 mm and a telescopic stroke of 3 mm, and two circular pressure blocks 10 with a diameter of 3 mm. The first spring 8 is arranged on the telescopic rod 9, and one pressure block 10 is fixed at each end of the telescopic rod 9. The pressure block 10 at either end of the spring pressure block 7 is fixedly installed in the upper cover plate 1. The circuit board 20 is fixed flat on the carrier by the elastic force of the first spring 8, thereby solving the deformation problem of the circuit board 20.

[0043] The reflow carrier 2 is provided with a circuit board supporting groove 11 , the size of which is 2 mm larger than the size of the circuit board 20 and is 5 mm sunken, so as to avoid the problem of the circuit board 20 being difficult to take out in actual operation due to thermal expansion and contraction.

[0044] The upper cover plate 1 is detachably connected to the reflow carrier 2 via four spring fixing buckles 12. Figure 5As shown, the spring fixing buckle 12 includes: a second spring 15 with a natural length of 7 mm and an outer diameter of 3 mm, a fixing rod 13 with a length of 24 mm and a diameter of 2 mm, and two fixing blocks 14 with a length of 10 mm, a width of 5 mm, and a thickness of 5 mm. The upper cover plate 1 is provided with four through holes 16 with a diameter of 2.5 mm. The fixing blocks 13 pass through the through holes 16. The fixing blocks 14 are fixed to both ends of the fixing rod 13. The second spring 15 is arranged on the fixing rod 13. The second spring 15 is located on the outer side of the upper cover plate. A buckle fixing hole 17 is provided on the reflux carrier 2 at a position corresponding to the spring fixing buckle 12. The length of the buckle fixing hole 17 is 11 mm and the width is 6 mm. By pressing the fixing block 14 on the outer side of the upper cover plate 1, the fixing block 14 at the other end is driven downward to pass through the buckle fixing hole 17 and then the spring fixing buckle is rotated so that the long side of the fixing block 14 is perpendicular to the long side of the buckle fixing hole 17. The upper cover plate 1 and the reflux carrier 2 are fixed by the elastic force of the second spring 15, which is convenient for actual operation.

[0045] Embodiment 3:

[0046] like Figure 1-Figure 3 As shown, the reflow heat absorption cover device of the complex circuit board assembly includes: an upper cover plate 1 and a reflow carrier 2, and the upper cover plate 1 and the supporting frame 3 are made of synthetic stone.

[0047] The interior of the upper cover plate 1 is designed with a stepped thickness of 2mm, 1.5mm, 3mm and 4mm according to the size and layout of the circuit board 20 components, which can balance the temperature of components of different sizes and reduce the damage to the components caused by temperature shock. The upper cover plate 1 is fixed with a support frame 3 by screws on all sides. The support frame 3 has a height of 5mm and a width of 3mm, so as to support the upper cover plate 1 to avoid the highest component height and avoid contact between the upper cover plate 1 and the components causing component displacement; each side of the support frame 3 is provided with 5 hot air inlet slots 4 to achieve the introduction of hot air to heat the circuit board 20 components as a whole.

[0048] Two positioning pins 18 are embedded on the support frame 3. The positioning pins 18 are in the shape of a cone with an upper diameter of 1.5mm and a lower diameter of 2.5mm. The tip of the positioning pin 18 is embedded downward on the support frame 3. A positioning pin hole 19 is also provided at a position corresponding to the positioning pin 18 on the reflow carrier 2. The diameter of the positioning pin hole 19 is 2.5mm. The expansion coefficient of the material of the positioning pin 18 is greater than the expansion coefficient of the material of the support frame 3. This embodiment adopts stainless steel material. Since the reflow heat absorption cover body is made of synthetic stone, its thermal expansion coefficient is generally 13 (unit: 10-6 / K). In actual use, it is found that if the positioning pin is made of a material with a thermal expansion coefficient smaller than that of synthetic stone, the positioning pin will fall off easily. The expansion coefficient of stainless steel is generally 14.4-16 (unit: 10-6 / K), and its expansion coefficient is greater than that of synthetic stone, which effectively avoids the problem of the positioning pin falling off easily.

[0049] A heating hole 5 is provided on the upper cover plate 1, and the heating hole 5 is located above a component whose required heat capacity is greater than the temperature of the hot air entering the hot air inlet slot 4. Open-hole barrier strips 6 are provided around the heating hole 5. The hot air directly heats the large component through the heating hole 5, and at the same time, the open-hole barrier strips 6 prevent the hot air from directly heating the surrounding small-sized components, thereby preventing the small components from being damaged due to excessive temperature.

[0050] Four spring pressure blocks 7 are fixedly installed inside the upper cover plate 1 at a position where the thickness of the upper cover plate 1 is 2 mm, and the spring pressure blocks 7 avoid all components and abut against the current plate 20. Figure 4 As shown, the spring pressure block 7 includes: a first spring 8 with a natural length of 11 mm and an inner diameter of 1 mm, a telescopic rod 9 with an overall length of 9 mm and a telescopic stroke of 3 mm, and two pressure blocks 10 with a length of 4 mm, a width of 2 mm, and a thickness of 2 mm. The first spring 8 is arranged on the telescopic rod 9, and one pressure block 10 is fixed at each end of the telescopic rod 9. The pressure block 10 at either end of the spring pressure block 7 is fixedly installed in the upper cover plate 1. The circuit board 20 is fixed flat on the carrier by the elastic force of the first spring 8, thereby solving the deformation problem of the circuit board 20.

[0051] The reflow carrier 2 is provided with a circuit board supporting groove 11 , the size of which is 1.1 mm larger than the size of the circuit board 20 and is sunken 2.8 mm, so as to avoid the problem of the circuit board 20 being difficult to take out in actual operation due to thermal expansion and contraction.

[0052] The upper cover plate 1 is detachably connected to the reflow carrier 2 via four spring fixing buckles 12. Figure 5As shown, the spring fixing buckle 12 includes: a second spring 15 with a natural length of 4 mm and an outer diameter of 2 mm, a fixing rod 13 with a length of 19 mm and a diameter of 1.5 mm, and two fixing blocks 14 with a length of 4 mm, a width of 2.5 mm, and a thickness of 3 mm. The upper cover plate 1 is provided with four through holes 16 with a diameter of 1.8 mm, the fixing blocks 13 pass through the through holes 16, the fixing blocks 14 are fixed to both ends of the fixing rod 13, the second spring 15 is arranged on the fixing rod 13, and the second spring 15 is located on the outer side of the upper cover plate. A snap fixing hole 17 is provided on the reflux carrier 2 at a position corresponding to the spring fixing buckle 12. The length of the snap fixing hole 17 is 4.5 mm and the width is 3 mm. By pressing the fixing block 14 on the outer side of the upper cover plate 1, the fixing block 14 at the other end is driven downward to pass through the snap fixing hole 17 and then the spring fixing buckle is rotated so that the long side of the fixing block 14 is perpendicular to the long side of the snap fixing hole 17. The upper cover plate 1 and the reflux carrier 2 are fixed by the elastic force of the second spring 15, which is convenient for actual operation.

[0053] Working principle: Place the circuit board 20 with the components pasted on it into the circuit board support groove 11 of the reflow carrier 2, place the upper cover 1 on the circuit board 20, so that the positioning pin 18 is inserted into the positioning pin hole 19, and drive the fixing block 14 at the other end to pass downward through the buckle fixing hole 17 by pressing the fixing block 14 on the outside of the upper cover 1, and then rotate the spring fixing buckle so that the long side of the fixing block 14 is perpendicular to the long side of the buckle fixing hole 17, so that the upper cover 1 and the reflow carrier 2 are connected, and the spring pressure block 7 is in contact with the circuit board 20, and finally the components are welded to the circuit board 20 by the hot air reflow soldering process, the hot air directly heats the large components through the heating holes 5, and at the same time, the open hole barrier strip 6 prevents the hot air from directly heating the surrounding small-sized components, and the small-sized components use the hot air inlet slot 4 to enter the heat inside the reflow heat absorption cover and then indirectly transmit it to the component surface, thereby completing the welding of the components and absorbing a certain amount of heat through the reflow heat absorption cover.

[0054] Based on the same inventive concept, the present invention also proposes a reflow soldering method for complex circuit board components, which includes: pasting components of different sizes to the above-mentioned circuit board, and then assembling the reflow heat absorption cover and the circuit board, so that the support frame of the heat absorption cover abuts against the support edge of the reflow carrier, inserting the positioning pin into the positioning hole, inserting the spring fixing buckle into the spring fixing hole, and the spring pressure block abuts against the circuit board, and finally using the hot air reflow soldering process to solder the component to the circuit board. The hot air directly heats the large component through the heating hole, and at the same time, the perforated barrier strip blocks the hot air from directly heating the surrounding small-sized components. The upper cover is provided with a hot air inlet slot to realize the introduction of hot air to heat the circuit board component as a whole.

[0055] The present invention proposes a reflow soldering method for a complex circuit board assembly, which uses a reflow heat absorbing hood to evenly transfer high-temperature heat waves into the assembly welding position, thereby avoiding the imbalance of heat source and temperature, achieving temperature balance and stability of the assembly, and thus improving the assembly welding success rate and assembly quality; the heat absorbing hood adopts a spring pressure block method for physical positioning, thereby avoiding the occurrence of circuit board warping and component and circuit board welding failure.

[0056] Although the spirit and principle of the present invention have been described with reference to several specific embodiments, it should be understood that the present invention is not limited to the disclosed specific embodiments, and the division of various aspects does not mean that the features in these aspects cannot be combined to benefit, and such division is only for the convenience of expression. The present invention is intended to cover various modifications and equivalent arrangements contained in the spirit and scope of the attached claims.

[0057] Regarding the limitation of the protection scope of the present invention, those skilled in the art should understand that, based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the protection scope of the present invention.

Claims

1. A reflow heat absorbing cover device for a complex circuit board assembly, the device comprising: An upper cover plate (1) and a reflow carrier (2), characterized in that a support frame (3) is fixedly installed around the upper cover plate (1), a plurality of hot air inlet slots (4) are provided on the support frame (3), a plurality of heating holes (5) are opened on the upper cover plate (1), a plurality of spring pressure blocks (7) are fixedly installed inside the upper cover plate (1), the reflow carrier (2) is provided with a circuit board support slot (11), and the upper cover plate (1) is detachably connected to the reflow carrier (2) via a plurality of spring fixing buckles (12).

2. A reflow heat absorbing cover device for a complex circuit board assembly according to claim 1, characterized in that: The upper cover plate (1) and the supporting frame (3) are fixed by screws; the supporting frame (3) has a height of 6 mm to 10 mm and a width of 2 mm to 6 mm.

3. The reflow heat absorbing cover device for a complex circuit board assembly according to claim 1, characterized in that: The interior of the upper cover plate (1) is designed to have a stepped thickness of 2 mm to 6 mm according to the size and layout of the circuit board assembly, and an opening barrier strip (6) is provided around the heating hole (5).

4. The reflow heat absorbing cover device for a complex circuit board assembly according to claim 1, characterized in that: The spring fixing buckle (12) comprises: a second spring (15), a fixing rod (13) and two rectangular fixing blocks (14); a plurality of through holes (16) are provided on the upper cover plate (1); the fixing rod (13) passes through the through holes (16); the fixing blocks (14) are fixed to two ends of the fixing rod (13); the second spring (15) is arranged on the fixing rod (13); the second spring (15) is located on the outer side of the upper cover plate; the diameter of the second spring (15) is greater than the diameter of the through hole (16); the diameter of the fixing rod (13) is less than the diameter of the through hole (16); a plurality of buckle fixing holes (17) are provided on the reflow carrier (2); the buckle fixing holes (17) are rectangular through holes with a length of 1 mm to 10 mm, a width of 1 mm to 5 mm and a thickness of 0.5 mm to 5 mm.

5. The reflow heat absorbing cover device for a complex circuit board assembly according to claim 1, characterized in that: The spring pressure block (7) comprises: a first spring (8), a telescopic rod (9) and two pressure blocks (10); the first spring (8) is arranged on the telescopic rod (9); one pressure block (10) is fixed to each of the two ends of the telescopic rod (9); and the pressure block (10) at either end of the spring pressure block (7) is fixedly installed in the upper cover plate (1).

6. The reflow heat absorbing cover device for a complex circuit board assembly according to claim 1, characterized in that: The upper cover plate (1) and the supporting frame (3) are made of high temperature resistant materials, including synthetic stone, stainless steel, and titanium alloy.

7. The reflow heat absorbing cover device for a complex circuit board assembly according to claim 1, characterized in that: A plurality of positioning pins (18) are embedded on the support frame (3), and the positioning pins (18) are in the shape of a cone with a diameter of 1 mm to 3 mm. The tip of the positioning pin (18) is embedded downward on the support frame (3). Positions on the reflow carrier (2) corresponding to the positioning pins (18) are also provided with positioning pin holes (19), and the diameter of the positioning pin holes (19) is 0.5 mm to 3 mm.

8. A reflow heat absorbing cover device for a complex circuit board assembly according to claim 7, characterized in that: The expansion coefficient of the material of the positioning pin (18) is greater than the expansion coefficient of the material of the supporting frame (3).

9. The reflow heat absorbing cover device for complex circuit board assembly according to claim 1, characterized in that: The size of the circuit board support groove (11) is 0.2 mm to 2 mm larger than the size of the circuit board and is sunken by 0.5 mm to 5 mm.

10. A reflow soldering method for a complex circuit board assembly, characterized in that: The method comprises: placing a complex circuit board in a containing space between an upper cover plate (1) of a reflow heat absorption cover device of a complex circuit board assembly as described in any one of claims 1 to 9 and a reflow carrier (2), and soldering the complex circuit board assembly in the reflow heat absorption cover device of the complex circuit board assembly using a hot air reflow soldering process.

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