A heat equalizing device for overall hot air soldering of inter-board connectors

Abstract

A heat equalization device for overall hot air soldering of connectors between boards according to the present invention includes a support, an air duct collector, a nozzle, and a grid air leak. The air duct collector is communicated with the air outlet of a hot air repair workstation. The grid air leak is fixed on the lower surface of the air duct collector, and the grid air leak is uniformly provided with arrayed through holes. The support is fixed with a printed circuit board, and the connector between boards is plugged on the printed circuit board. The nozzle includes a reduction section and a vertical section. Two side plates in the length direction of the vertical section extend vertically downward and then bend inward to form an extension part, and the lead solder joints of the connector between boards are surrounded in the extension part. The reduction section is symmetrically arranged outward along two side plates in the length direction of the vertical section. The upper ends of two first air guide plates in the air guide plate are fixed in the reduction section after being fitted to form an isosceles triangle. The upper ends of two second air guide plates are spliced with the lower ends of the corresponding first air guide plates and are parallel to the inner wall of the vertical section. The grid air leak is fixed at the upper end of the reduction section.

Description

Technical Field

[0001] The present invention belongs to the field of hot air soldering in electronic assembly, and particularly relates to a heat equalizing device for overall hot air soldering of board-to-board connectors. Background Art

[0002] Board-to-board connectors are key components for realizing high-density interconnection between printed circuit boards in high-reliability computers and electronic products, and are widely used in various computer products.

[0003] However, since the leads of board-to-board connectors are gold-plated, the gold pins cannot be contaminated during soldering. Therefore, high requirements are imposed on the soldering skills of soldering operators. Especially for the soldering of multi-row, fine-pitch, and long-pin board-to-board connectors, it has always been a difficult problem in the industry. When using a soldering iron for manual soldering, due to the high density of board-to-board connectors, it is difficult to operate the soldering iron, and it is easy to contaminate the gold pins. Moreover, it is difficult to penetrate the tin in the large-area copper-clad parts, and the soldering difficulty is high. When using overall hot air soldering, since the hot air source is an external cyclone, the heating efficiency of the traditional nozzle is low, and the temperature difference between the solder joints on both sides and the middle solder joint of the board-to-board connector is more than 40°C. The qualified rate of a single soldering is less than 5%. In addition, due to the low heat utilization efficiency, the heating time is long, and the risk of damage to the board-to-board connector body increases significantly. As a result, the method of overall hot air soldering has not been applied in the industry.

[0004] Currently, the assembly of board-to-board connectors for high-reliability electronic products is still mainly achieved by highly skilled soldering operators through manual soldering, with low soldering efficiency and high requirements for operating skills. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a heat equalizing device for overall hot air soldering of board-to-board connectors, which can achieve synchronous and uniform heating of all solder joints of the board-to-board connector, greatly improving the soldering quality and efficiency of the board-to-board connector.

[0006] The present invention is realized through the following technical solutions:

[0007] A heat equalizing device for overall hot air soldering of board-to-board connectors includes a support, a hollow air duct collector, a nozzle, and a grid air leak in a sheet structure. The upper surface of the air duct collector is connected to the air outlet of the hot air rework workstation. The upper surface of the grid air leak is fixed to the lower surface of the air duct collector, and the area corresponding to the hollow area of the air duct collector is evenly provided with arrayed through holes.

[0008] The upper surface of the support is fixed with a printed circuit board, and the board-to-board connector is inserted into the printed circuit board.

[0009] The air nozzle includes a wind guide plate, a reduced section and a vertical section of an integral structure. The vertical section is of a cuboid structure. Two side plates in the length direction of the vertical section extend vertically downward and then bend inward to form extension parts. The lead soldering points of the board-to-board connector are located directly below the vertical section and are surrounded by the extension parts. The reduced section is symmetrically arranged outward along the two side plates in the length direction of the vertical section. The wind guide plate includes two first wind guide plates and two second wind guide plates. The upper ends of the two first wind guide plates are fitted together to form an isosceles triangle and are fixed in the reduced section. The upper ends of the two second wind guide plates are respectively spliced with the lower ends of the corresponding first wind guide plates and are arranged parallel to the inner wall of the vertical section. The lower surface of the grid air leak is fixed to the upper end of the reduced section. The array of through holes corresponds to the hollow part of the reduced section.

[0010] Preferably, it further includes a hot air rework workstation platform. The support is of a rectangular structure. There are wind holes arranged in an array on the support. The support is fixed on the upper surface of the hot air rework workstation platform.

[0011] Preferably, a notch corresponding to the board-to-board connector is provided on one side edge in the length direction of the support. Cylindrical protrusions are arranged along the height direction of the support at the edge of the notch. The protrusions are symmetrically arranged along the center of the support. The groove of the board-to-board connector is inserted into the protrusions.

[0012] Preferably, bosses with an isosceles right triangle cross-section are provided at the four corners of the support along the height direction of the support. Circular grooves are provided in the bosses. The through holes in the printed circuit board are aligned with the circular grooves. Fasteners are installed in the through holes and the circular grooves.

[0013] Furthermore, the fastener is a knurled screw.

[0014] Preferably, the hollow area of the air duct collector is square, the grid air leak is circular. The center of the area with the array of through holes in the grid air leak coincides with the center of the circle of the grid air leak. The side length of the area occupied by the array of through holes is 2 / 3 of the side length of the hollow area of the air duct collector.

[0015] Preferably, the two side plates in the length direction of the vertical section extend vertically downward and then bend inward by 49° to 55° to form the extension parts.

[0016] Preferably, the inner diameter of the through holes in the grid air leak is 0.8 mm to 1.2 mm, and the inner diameter of the wind holes is 5 mm to 8 mm.

[0017] Preferably, the two first wind guide plates are symmetrically distributed along the central position in the length direction of the reduced section. Each first wind guide plate is symmetrically distributed with the corresponding side plate of the reduced section. The two second wind guide plates are symmetrically distributed along the central position in the length direction of the vertical section.

[0018] Further, the angle formed after the second air deflector is spliced with the corresponding first air deflector is 150° to 165°, and the distance between the second air deflector and the inner wall of the vertical section is 2.5 mm to 3.5 mm.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] The present invention provides a heat equalizing device for overall hot air soldering of board-to-board connectors. By using a hot air rework workstation, a nozzle assembly composed of an air duct collector, a nozzle, and a grid air leak in a sheet structure is applied. The upper surface of the air duct collector is communicated with the air outlet of the hot air rework workstation. In this way, when the area of the grid air leak corresponding to the hollow area of the air duct collector is uniformly provided with arrayed through holes, hot air with uniform temperature can be further introduced into the nozzle. The nozzle includes a reduced section and a vertical section in an integrated structure. The two side plates of the vertical section extend vertically downward and then bend inward to form an extension part. Since the upper surface of the support is fixed with a printed circuit board and the board-to-board connector is plugged on the printed circuit board, the extension part can surround the lead solder joints of the board-to-board connector. In the nozzle, the reduced section, the vertical section, the first air deflector, and the two second air deflectors form a uniform air duct, which can achieve that the temperature difference between the solder joints on both sides and the middle solder joints of the board-to-board connector is within 5°C, realizing synchronous and same-amplitude heating of all solder joints, and greatly improving the quality and efficiency of soldering the board-to-board connector. The present invention realizes strong convection of externally rotating hot air, realizes forced heat exchange of hot air through the air duct collector and the grid air leak, achieves uniform hot air temperature, the nozzle realizes strong convection of hot air between multiple rows of leads of the board-to-board connector on both sides, and realizes direct heating of the solder joints by hot air. By using the hot air rework workstation to apply the nozzle assembly, overall soldering of the board-to-board connector is realized, and the utilization efficiency of hot air is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional schematic diagram of the installation and application of the heat equalizing nozzle assembly of the present invention.

[0022] Figure 2 is Figure 1 The three-dimensional schematic diagram of the disassembled heat equalizing nozzle assembly in

[0023] Figure 3 is Figure 2 The top view of the grid air leak in

[0024] Figure 4a is Figure 2 The three-dimensional schematic diagram of the double-Y-shaped nozzle in

[0025] Figure 4b is Figure 4a The sectional view at A-A in

[0026] Figure 5 It is the sectional view of the soldering process of the board-to-board connector of the present invention.

[0027] Figure 6 is Figure 1 a three-dimensional schematic diagram of the fixed support in

[0028] In the figure: nozzle assembly 1, air duct collector 1-1, grid air leak 1-2, projection area of the air duct collector outlet 1-2-1, grid air outlet 1-2-2, nozzle 1-3, air duct 1-3-1, reduction section 1-3-2, vertical section 1-3-3, first air guiding plate 1-3-4, second air guiding plate 1-3-5, hot air rework workstation 2, printed circuit board 3, support 4, protrusion 4-1, air hole 4-2, hot air rework workstation platform 5, board-to-board connector 6, knurled screw 7, guiding pin 8. Specific embodiments

[0029] The following further describes the present invention in detail with specific embodiments, which is an explanation rather than a limitation of the present invention.

[0030] A heat equalizing device for overall hot air soldering of board-to-board connectors according to the present invention, as Figure 1 shown, includes a nozzle assembly 1, a hot air rework workstation 2, a printed circuit board 3, a support 4, a hot air rework workstation platform 5, and a board-to-board connector 6. The nozzle assembly 1 is communicated with the air outlet of the hot air rework workstation 2. The support 4 is of a rectangular structure and is fixed on the upper surface of the rectangular hot air rework workstation platform 5. The printed circuit board 3 is fixed on the upper surface of the support 4 by a knurled screw 7. In the figure, there are 4 L-shaped structures with 2 holes near the knurled screw 7, which are the structures of the printed circuit board 3 itself. The board-to-board connector 6 is inserted into the printed circuit board 3 from below and is blocked by the lower structure of the nozzle assembly 1 in the figure.

[0031] As Figure 2 shown, the heat equalizing nozzle assembly 1 includes an air duct collector 1-1, a grid air leak 1-2 in the shape of a circular sheet, and a nozzle 1-3. The main structure of the air duct collector 1-1 is a cuboid with a square cross-section. A square-shaped hollow area is opened in the cuboid along the height direction. The upper and lower ends of the cuboid both extend horizontally to form circles with the same diameter. The upper surface of the air duct collector 1-1 is communicated with the air outlet of the hot air rework workstation 2. Then in combination with Figure 4a and Figure 4b, the air nozzle 1-3 includes a wind guide plate, and a reduced section 1-3-2 and a vertical section 1-3-3 of an integral structure. The vertical section 1-3-3 is in the shape of a cuboid. After the two side plates in the length direction of the vertical section 1-3-3 extend vertically downward and then bend inward, an extension part of the air nozzle 1-3 is formed. The lead solder joints of the board connector 6 are located directly below the vertical section 1-3-3 and are finally surrounded by the extension part. The reduced section 1-3-2 is surrounded by 4 side plates. The lower end of the reduced section 1-3-2 has the same shape as the vertical section 1-3-3. Its two side plates along the length direction of the vertical section 1-3-3 are symmetrically arranged outward, and the other 2 side plates are in the shape of isosceles trapezoids of the same shape and are symmetrically distributed inward from the upper end of the vertical section 1-3-3. The upper end of the reduced section 1-3-2 extends horizontally to form a circular structure with the same diameter as the grid air leak 1-2. The wind guide plate includes two first wind guide plates 1-3-4 and two second wind guide plates 1-3-5. After the upper ends of the two first wind guide plates 1-3-4 are fitted together to form an isosceles triangle, they are fixed in the reduced section 1-3-2 by fitting with the inner wall of the reduced section 1-3-2. The upper ends of the two second wind guide plates 1-3-5 are respectively spliced with the lower ends of the corresponding first wind guide plates 1-3-4 to form an integral structure and are arranged parallel to the inner wall of the vertical section 1-3-3. As Figure 3 shown, the grid air leak 1-2 is evenly provided with arrayed through holes in the area corresponding to the hollow area of the air duct collector 1-1. The center of the square area with the arrayed through holes coincides with the center of the circle of the grid air leak 1-2. Since the circular part at the lower end of the air duct collector 1-1, the grid air leak 1-2, and the upper circular part of the reduced section 1-3-2 of the air nozzle 1-3 have the same shape, 4 through holes with aligned round holes are evenly opened at their edges. The grid air leak 1-2 is placed between the reduced section 1-3-2 of the air nozzle 1-3 and the lower end of the air duct collector 1-1. The arrayed through holes correspond to the hollow part of the reduced section 1-3-2 and are fastened together by four groups of evenly distributed screws and corresponding nuts. The uniform hot air flows downward from the grid air outlet 1-2-2 and reaches the air duct 1-3-1 formed by the wind guide plate, the reduced section 1-3-2, and the vertical section 1-3-3 in the air nozzle 1-3.

[0032] From Figure 6It can be seen that there are bosses with an isosceles right triangle cross-section provided at the four corners of the support 4 along the height direction of the support 4. A circular groove is provided in the boss. After the through holes in the printed circuit board 3 are aligned with the circular groove, the knurled screw 7 is installed to realize the installation of the printed circuit board 3. The knurled screw 7 is made of nylon material, which can ensure that the surface of the printed circuit board 3 is not damaged. In addition, air holes 4-2 arranged in an array are provided in the area between the bosses. The inner diameter of the air holes 4-2 is 5 mm to 8 mm, which is convenient for the preheating heat of the hot air rework workstation platform 5 to be transferred to the surface of the printed circuit board 3, realizing the preheating of the surface of the printed circuit board 3, and is more conducive to completing the hot air overall soldering of the board-to-board connector 6 on the printed circuit board 3. A notch corresponding to the board-to-board connector 6 is provided on one side of the support 4 in the length direction. A cylindrical protrusion 4-1 is provided along the height direction of the support 4 at the edge of the notch. The protrusion 4-1 is symmetrically arranged along the center of the support 4. The groove of the board-to-board connector 6 is inserted into the protrusion 4-1, which can realize the accurate positioning and installation of the board-to-board connector 6.

[0033] Specifically, the side length of the area occupied by the arrayed through holes in the grid air leak 1-2 is 2 / 3 of the side length of the hollow area of the air duct collector 1-1, and the inner diameter of the through hole is 0.8 mm to 1.2 mm. The grid air leak 1-2 is in a closed state in the outer 1 / 3 area of the four sides of the projection area 1-2-1 of the air duct collector outlet, and can be combined with the air duct collector 1-1 installed above it to realize the strong convection of the external rotation hot air.

[0034] It should be noted that as Figure 5 It can be seen that the hot air rework workstation 2 is self-equipped with a guide pin 8. A through hole with the same outer diameter as the guide pin 8 is provided in the center of the grid air leak 1-2, and corresponding notches are also provided in the two first air guide plates 1-3-4. Therefore, the guide pin 8 is first inserted into the center of the grid air leak 1-2 through the hollow area of the air duct collector 1-1, and then extends into the notches of the two first air guide plates 1-3-4. There are two round holes self-equipped at the place where the board-to-board connector 6 faces vertically. The air duct collector 1-1, the air nozzle 1-3, and the grid air leak 1-2 are made of stainless steel, and the support 4 is made of aluminum.

[0035] When specifically designing the air nozzle 1-3, the internal air duct 1-3-1 also needs to be a symmetric structure. Therefore, the two first air guide plates 1-3-4 are symmetrically distributed along the central position in the length direction of the reduction section 1-3-2, and each first air guide plate 1-3-4 is symmetrically distributed with the side plate of the corresponding reduction section 1-3-2. The two second air guide plates 1-3-5 are symmetrically distributed along the central position in the length direction of the vertical section 1-3-3. A double Y-shaped air duct 1-3-1 with the same shape can be formed in the air nozzle 1-3. The angle formed after the second air guide plate 1-3-5 is spliced with the corresponding first air guide plate 1-3-4 is 150° to 165°, and the distance between the second air guide plate 1-3-5 and the inner wall of the vertical section 1-3-3 is 2.5 mm to 3.5 mm. The uniform hot air flowing out from the middle of the grid air leak 1-2 flows from the top to the outlet of the air nozzle 1-3 (i.e., the extension part described above) in the air duct 1-3-1. The outlet is directly opposite to the lead solder joints of the inter-board connector 6, realizing direct hot air heating of the solder joints. The extension part formed after the two side plates in the length direction of the vertical section 1-3-3 extend vertically downward and then bend inward by 49° to 55° is the same as the angle described in Figure 4b and can realize strong convection between the hot air on both sides among the multi-row leads of the inter-board connector 6, improving the thermal utilization efficiency.

[0036] Taking the soldering of the long-pin gold-plated inter-board connector with the model CY45B96LZ used in a certain product as an example of the present invention. According to the size of the inter-board connector, the air duct collector 1-1, the grid air leak 1-2, the air nozzle 1-3 and the support 4 with corresponding sizes are designed. Four groups of screws and nuts are used to assemble the air duct collector 1-1, the grid air leak 1-2 and the air nozzle 1-3 to form the heat uniforming air nozzle assembly 1. The heat uniforming air nozzle assembly 1 is installed at the lower end of the air outlet of the hot air rework workstation 2. The printed circuit board 3 is fastened to the support 4 through the knurled screws 7 at the four corners, and the support 4 is fixed on the platform 5 of the hot air rework workstation to complete the overall hot air soldering of the inter-board connector 6 on the printed circuit board 3.

[0037] During the welding process, the temperatures of the solder joints on both sides and the middle of the inter-board connector 6 are monitored in real time. During the whole welding process, the temperature difference between the solder joints on both sides and the middle of the inter-board connector 6 is within 5°C, realizing synchronous and same-amplitude heating of all the solder joints of the inter-board connector 6. All 96 solder joints of the connector are welded qualified at one time, and the tin penetration rate of the solder joints reaches 100%. Moreover, the body of the inter-board connector is intact and undamaged. At the same time, when using the air nozzle assembly 1 to implement the overall hot air welding of the inter-board connector 6, compared with manual soldering with an electric soldering iron, the efficiency is increased by more than 6 times.

[0038] After verification, applying the device designed by the present invention can realize high-quality overall hot air welding of the inter-board connector, solve the bottleneck problem of high skill requirements for manual soldering with an electric soldering iron, and at the same time greatly improve the quality and efficiency of the inter-board connector welding.

Claims

1. A heat equalizing type device for overall hot air soldering of board - to - board connectors, characterized in that, It includes a support (4), an air duct collector (1-1) with a hollow structure, an air nozzle (1-3), and a grid air leakage (1-2) with a sheet structure. The upper surface of the air duct collector (1-1) is communicated with the air outlet of the hot air rework workstation (2). The upper surface of the grid air leakage (1-2) is fixed to the lower surface of the air duct collector (1-1). The area of the grid air leakage (1-2) corresponding to the hollow area of the air duct collector (1-1) is evenly provided with arrayed through holes. A printed circuit board (3) is fixed on the upper surface of the support (4), and a board-to-board connector (6) is inserted into the printed circuit board (3). The air nozzle (1-3) includes a wind guiding plate, a reduced section (1-3-2) and a vertical section (1-3-3) with an integral structure. The vertical section (1-3-3) is a cuboid structure. Two side plates in the length direction of the vertical section (1-3-3) extend vertically downward and then bend inward to form extension parts. The lead soldering points of the board-to-board connector (6) are located directly below the vertical section (1-3-3) and are surrounded by the extension parts. The reduced section (1-3-2) is symmetrically arranged outward along the two side plates in the length direction of the vertical section (1-3-3). The wind guiding plate includes two first wind guiding plates (1-3-4) and two second wind guiding plates (1-3-5). The upper ends of the two first wind guiding plates (1-3-4) are joined together to form an isosceles triangle and then fixed in the reduced section (1-3-2). The upper ends of the two second wind guiding plates (1-3-5) are respectively spliced with the lower ends of the corresponding first wind guiding plates (1-3-4) and are arranged parallel to the inner wall of the vertical section (1-3-3). The lower surface of the grid air leakage (1-2) is fixed to the upper end of the reduced section (1-3-2), and the arrayed through holes correspond to the hollow part of the reduced section (1-3-2). The two first wind guiding plates (1-3-4) are symmetrically distributed along the central position in the length direction of the reduced section (1-3-2). Each first wind guiding plate (1-3-4) is symmetrically distributed with the corresponding side plate of the reduced section (1-3-2). The two second wind guiding plates (1-3-5) are symmetrically distributed along the central position in the length direction of the vertical section (1-3-3). The angle formed after the second wind guiding plate (1-3-5) is spliced with the corresponding first wind guiding plate (1-3-4) is 150° to 165°. The distance between the second wind guiding plate (1-3-5) and the inner wall of the vertical section (1-3-3) is 2.5 mm to 3.5 mm. It also includes a hot air rework workstation platform (5). The support (4) is a rectangular structure, and the support (4) is provided with arrayed air holes (4-2). The support (4) is fixed on the upper surface of the hot air rework workstation platform (5).

2. The heat equalizing type device for overall hot air soldering of the board-to-board connector according to claim 1, wherein A notch corresponding to the board-to-board connector (6) is provided on one side edge in the length direction of the support (4). A cylindrical protrusion (4-1) is provided along the height direction of the support (4) at the edge of the notch. The protrusion (4-1) is symmetrically arranged along the center of the support (4). The groove of the board-to-board connector (6) is inserted into the protrusion (4-1).

3. The heat equalizing type device for overall hot air soldering of the board-to-board connector according to claim 1, characterized in that, Convex platforms with an isosceles right triangle cross-section are provided at the four corners of the support (4) along the height direction of the support (4). Circular grooves are provided in the convex platforms. The through holes in the printed circuit board (3) are aligned with the circular grooves, and fasteners are installed in the through holes and the circular grooves.

4. The heat equalizing type device for overall hot air soldering of the board-to-board connector according to claim 3, characterized in that, The fastener is a knurled screw (7).

5. The soaking type device for overall hot air soldering of the inter-board connector according to claim 1, wherein, The hollow area of the air duct collector (1-1) is square, and the grid air leak (1-2) is circular. The center of the area with arrayed through holes in the grid air leak (1-2) coincides with the center of the circle of the grid air leak (1-2). The side length of the area occupied by the arrayed through holes is 2 / 3 of the side length of the hollow area of the air duct collector (1-1).

6. The heat equalizing type device for overall hot air soldering of the inter-board connector according to claim 1, wherein, Two side plates in the length direction of the vertical section (1-3-3) extend vertically downward and then bend inward by 49° to 55° to form an extension part.

7. The heat equalizing type device for overall hot air soldering of the inter-board connector according to claim 1, characterized in that, The inner diameter of the through holes in the grid air leak (1-2) is 0.8 mm to 1.2 mm, and the inner diameter of the air holes (4-2) is 5 mm to 8 mm.

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