A general-purpose shape-retaining tool and assembly method for suppressing high-temperature warping of PCBs during reflow soldering

Abstract

The present application relates to a kind of general shape tool for inhibiting PCB reflow soldering high temperature warping and assembly method.The tool includes tray, several discrete movable support column and fastener;Tray is arrayed with several support column mounting hole, the bottom surface of each support column mounting hole is provided with countersunk structure;Movable support column includes support column main body, first connecting part arranged at the top end of support column main body and second connecting part arranged at the bottom end of support column main body;Second connecting part is flange, at least one waist slot hole is formed in flange, waist slot hole is matched with support column mounting hole, so that movable support column can be adjusted by translation, rotation relative to tray;Fastener is used to realize the locking and fixing of movable support column and tray, PCB and movable support column.The shape tool can realize global position adjustment, bottom surface smooth support and high temperature anti-loose, to realize the welding process of quick change type, low cost and high reliability.

Description

Technical Field

[0001] This invention relates to the field of PCB surface mount soldering fixture technology, specifically to a universal conformal fixture and assembly method for suppressing high-temperature warpage during PCB reflow soldering. Background Technology

[0002] In surface mount technology (SMT) manufacturing, PCBs undergo a high-temperature heating and cooling process as they pass through a reflow oven. For PCBs that are large, thin, or irregularly shaped, warping is easily caused due to mismatched thermal expansion coefficients and uneven heating. This warping can lead to serious quality problems such as cold solder joints, bridging, and even component detachment.

[0003] In existing technologies, customized, dedicated support fixtures are typically used to fix PCBs. However, such fixtures must be designed and manufactured specifically for the dimensions and hole positions of the PCB, making them non-universal. Once the product model changes, the old fixture becomes obsolete, requiring the investment of time and resources to manufacture a new fixture, resulting in extremely poor flexibility. Although some universal support plates with adjustable support pins exist, their adjustment range is limited, allowing only point-to-point positioning on a grid, making continuous position and angle fine-tuning impossible. Furthermore, their structures are relatively complex, making it difficult to quickly and accurately adapt to PCBs with varying mounting hole spacing and shapes. In addition, after locking, the bottom surface of existing fixtures often becomes uneven due to protruding fasteners, making them prone to swaying and shifting during transport on the reflow oven conveyor belt, significantly reducing support stability. At the same time, the high temperature and vibration inside the oven can also cause the threaded connections to loosen, affecting support stability.

[0004] Therefore, there is an urgent need for a tooling solution that is highly versatile, easy to adjust, can ensure the overall support flatness, and can effectively suppress welding warping. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a conformal fixture and assembly method for suppressing high-temperature warping of PCBs during reflow soldering. This conformal fixture is simple in structure, highly versatile, and provides stable support. It enables full-range position adjustment, stable bottom support, and high-temperature anti-loosening, thereby achieving rapid changeover, low cost, and high reliability in the soldering process.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect of the present invention, a universal conformal tooling for suppressing high-temperature warping of PCBs during reflow soldering is disclosed, comprising a tray, a plurality of separately arranged movable support columns, and fasteners. The tray has a number of support column mounting holes arranged in an array, and the bottom surface of each support column mounting hole is provided with a countersunk structure. The movable support column includes a support column body, a first connecting part located at the top of the support column body, and a second connecting part located at the bottom of the support column body; The second connecting part is a flange, and the flange has at least one waist-shaped slot. The waist-shaped slot cooperates with the support column mounting hole, so that the movable support column can be translated and rotated relative to the tray for adjustment. The fasteners are used to lock and fix the movable support column to the tray and the PCB to the movable support column.

[0007] As a further improvement to the above technical solution, the tray is an aluminum alloy flat plate formed by machining.

[0008] As a further improvement to the above technical solution, the tray is provided with a plurality of support column mounting holes arranged in an array.

[0009] As a further improvement to the above technical solution, the movable support column is made of metal material.

[0010] As a further improvement to the above technical solution, the top of the support column body is provided with a first connecting part, which is used to cooperate with fasteners to realize the installation and fastening of the PCB.

[0011] As a further improvement to the above technical solution, the bottom of the support column body is provided with a second connecting part for installation in conjunction with the support column mounting hole on the tray.

[0012] As a further improvement to the above technical solution, the first connecting part is a threaded hole.

[0013] As a further improvement to the above technical solution, the countersunk structure adopts either a tapered countersunk hole or a cylindrical stepped hole to accommodate the screw head.

[0014] As a further improvement to the above technical solution, the fastener includes a first screw, a nut, a second screw, and a flat washer; After the first screw passes through the waist-shaped slot and the support column mounting hole in sequence, it is locked with the nut to lock the movable support column to the tray. The second screw, along with a flat washer, passes through the mounting hole on the PCB and engages with the threaded hole of the first connection part to achieve a secure connection between the PCB and the top of the movable support column.

[0015] In a second aspect of the invention, a PCB assembly method using a universal conformal fixture for suppressing high-temperature warpage during PCB reflow soldering is disclosed, the method comprising the following steps: S1. According to the mounting hole distribution of the PCB to be assembled, align several movable support columns with the support column mounting holes on the tray through the waist-shaped slot holes of the second connection part, and use fasteners to pre-tighten and fix them so that the movable support columns can adjust their position and angle relative to the tray. S2. Place the PCB to be assembled on the top of each movable support column, align the mounting holes on the PCB with the first connecting part, and lock and fix the PCB to the movable support column with fasteners. S3. Adjust the position and angle of each movable support column so that the top of each support column is in contact with the bottom surface of the PCB, tighten the fasteners, and fix the movable support column and the tray into a whole to complete the PCB assembly.

[0016] Compared with the prior art, the advantages of the present invention are: (1) The present invention sets the movable support column as a completely separate movable component. It connects to the tray by using the waist-shaped slot on the bottom flange. It can achieve continuous stepless fine adjustment of position and angle in a two-dimensional plane. It can accurately adapt to PCBs with arbitrary hole spacing, different shapes and thicknesses. No special fixtures are required. It can adapt a single set of tooling to multiple types of products and improve the general coverage of tooling.

[0017] (2) The present invention adopts a multi-point rigid support locking structure, which rigidly fastens the PCB to the support columns at multiple points. All the support columns are finally locked on the rigid tray with high flatness, forming a stable three-point positioning overall support structure. This can greatly resist the thermal stress generated by the PCB under the high temperature of reflow soldering, significantly suppress the warping deformation of the PCB board surface, and improve the flatness of PCB soldering and the quality of finished products.

[0018] (3) By setting a countersunk structure on the bottom surface of the mounting hole of the tray, the head of the locking screw can be completely stored and hidden, which completely eliminates the hidden danger of the tooling being unstable due to the protrusion of the locking screw head. This ensures that the tooling is stable and tilt-free during the conveying process of the workbench and reflow soldering conveyor belt, and provides consistent and reliable support for the PCB throughout the process.

[0019] (4) The tray in this invention is a universal component that can be reused for a long time. The movable support column is a standard part or a simple machined part. When switching products, there is no need to make a new fixture. Only the layout of the movable support column needs to be adjusted, which greatly saves fixture costs and production preparation time. It is especially suitable for PCB production mode with multiple varieties and small batches. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the conformal tooling and PCB assembled in this invention; Figure 2 This is a schematic diagram of the movable support column in this invention; Figure 3 This is a schematic diagram of the tray structure in this invention; Figure 4 for Figure 1 A partially enlarged sectional view at point A in the middle; Figure 5 This is a schematic diagram of the PCB to be soldered. Figure 6 This is a schematic diagram of conformal tooling adapted to two different mounting hole layouts of PCBs in this invention.

[0021] in: 1. Tray; 11. Support column mounting hole; 12. Countersunk structure; 2. Movable support column; 21. Support column body; 22. First connecting part; 23. Second connecting part; 24. Waist-shaped slot hole; 25. Limiting slot; 3. PCB; 31. PCB mounting hole; 4. First screw; 5. Nut; 6. Second screw; 7. Flat washer. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings: like Figures 1-6 The invention illustrates a universal conformal fixture for suppressing high-temperature warpage of PCBs during reflow soldering, comprising a tray 1, several separately arranged movable support columns 3, and fasteners. The fixture is used to clamp the PCB to be soldered. Each movable support column 2 is an independent, separate unit; there is no connecting or limiting structure between any two columns. Each column can independently move and rotate on the tray, adapting to the irregularly distributed mounting holes of various irregularly shaped PCBs. This invention first secures the PCB 3 to the tops of the multiple movable support columns 3, then assembles the entire assembly onto the high-precision, flat aluminum alloy tray 1. Relying on the rigid support and constraint of the tray's reference plane and the multiple equally high movable support columns, it effectively counteracts the internal stress generated by the PCB during the high temperature and thermal expansion and contraction of reflow soldering, reducing PCB warpage and improving the flatness and soldering quality of the PCB during reflow soldering. Traditional PCB soldering fixtures often have customized opening structures, with one fixture corresponding to one PCB, resulting in high changeover costs and poor adaptability. This invention eliminates the need for hole modification or tooling replacement. It allows for rapid changeover of different PCB products simply by fine-tuning the position of the support columns, thus shortening production line changeover time and reducing tooling development and manufacturing costs.

[0023] Specifically, such as Figure 3As shown, the tray 1 has a plurality of support column mounting holes 11 arranged in an array, and each support column mounting hole 11 has a countersunk structure 12 on its bottom surface; the movable support column 2 includes a support column body 21, a first connecting part 22 located at the top of the support column body 21, and a second connecting part 23 located at the bottom of the support column body 21; the second connecting part 23 is a flange, and the flange has at least one waist-shaped slot 24, which cooperates with the support column mounting holes 11, so that the movable support column 2 can be translated and rotated relative to the tray 1 for adjustment; the fasteners are used to lock and fix the movable support column 2 to the tray 1 and the PCB 3 to the movable support column 2 respectively. The present invention adopts a separate adjustable structure for the tray and the movable support column, and the flange at the bottom of the support column is provided with a waist-shaped slot structure, which can realize the radial translation and continuous fine adjustment of the axial angle of the support column. It can adaptively align and fix according to the hole spacing and installation position of different PCBs, and is not limited by the PCB thickness, shape contour and size. It can adapt to the welding support requirements of various irregular and high-density PCBs.

[0024] As a further improvement to the above technical solution, the tray 1 is a machined aluminum alloy plate. The tray 1 has a plurality of support column mounting holes 11 arranged in an array. The tray 1 is a plate-shaped substrate made of aluminum alloy through precision milling, which can stably maintain the overall planar reference, resist the deformation caused by the high temperature of reflow soldering, and avoid exacerbating PCB warping due to the deformation of the tray itself.

[0025] As a further improvement to the above technical solution, the movable support column 2 is made of high-temperature resistant metal material, preferably stainless steel, machined to shape. It exhibits excellent high-temperature resistance and corrosion resistance, and is not easily deformed or corroded under the high-temperature cycling environment of reflow soldering, ensuring long-term stable multi-point equal-height support accuracy. The main body 21 of the support column has a cylindrical structure, and the cylinder diameter should be as small as possible to improve versatility. Preferably, the cylinder diameter is 5.5mm and the height is 12mm, making it compact and highly versatile, adaptable to PCBs with different assembly densities and shapes. The main body 21 of the support column has optimal height tolerance; the height difference between each movable support column should ensure that the flatness of the PCB meets the requirements after assembly. The movable support column 2 is integrally machined from stainless steel, exhibiting excellent high-temperature resistance, corrosion resistance, and high-temperature creep resistance. It can withstand repeated high-temperature cycling conditions during reflow soldering for extended periods, is not easily deformed or failed, continuously ensures multi-point equal-height support accuracy, and results in a longer tooling service life and higher stability.

[0026] As a further improvement to the above technical solution, such as Figure 2As shown, the top of the support column body 21 is provided with a first connecting part 22, which is specifically an M2 threaded hole, used to cooperate with fasteners to realize the installation and fastening of the PCB. The bottom of the support column body 21 is designed with a second connecting part 23 with a flange structure. The flange has a pre-reserved waist-shaped slot for installation with the support column mounting holes 11 on the tray 1, realizing the fine adjustment and adaptation of the position and angle of the support column. In this embodiment, the PCB3 is irregularly shaped with unlimited thickness and is designed with mechanical mounting holes. The fasteners are M2 stainless steel screws, nuts and flat washers, which are used to lock and fix the tray 1 and the movable support column 2, and the movable support column 2 and the PCB3, respectively.

[0027] As a further improvement to the above technical solution, the movable support column 2 is assembled in sections through the first connecting part 22 and the second connecting part 23, wherein the first connecting part 22 is used to connect the PCB and the second connecting part 23 is used to connect the tray 1.

[0028] Specifically, the first connecting part 22 is a threaded hole. During assembly, the second screw 6 passes through the PCB mounting hole 31 and the flat washer 7 on the PCB3 in sequence and is then screwed into the threaded hole, so that the PCB can be reliably fastened to the top of the movable support column 2.

[0029] Furthermore, the second connecting part 23 is a flange, on which at least one oblong slot 24 is provided, and the support column mounting hole 11 on the tray 1 is a circular through hole; by passing the first screw 4 through the support column mounting hole 11 and the oblong slot 24, and locking it with a nut 5 on the front of the oblong slot 24, the connection and fixation of the movable support column 2 and the tray 1 are realized. Relying on the structural characteristics of the oblong slot, the movable support column can achieve continuous fine adjustment of radial translation and circumferential angle. The second connecting part and the support column mounting hole on the tray are connected by an adjustable relative position, so that the movable support column can adjust its installation position and angle relative to the tray, and adaptively position and fix it according to the actual distribution of the mounting holes on the PCB, adapting to the support requirements of various irregular PCBs.

[0030] Furthermore, the top surface of the second connecting part 23 is provided with a limiting groove 25 for holding the nut 5 and preventing the nut from rotating with the first screw 4 during the tightening process. The limiting groove 25 is a rectangular limiting groove formed on the top surface of the second connecting part 23, and its shape and size match the external dimensions of the nut. The limiting groove 25 structure can effectively lock and limit the nut, preventing the nut from spinning freely and slipping during the tightening process. It can be quickly assembled and locked by a single person, and is convenient and efficient to assemble and disassemble.

[0031] Furthermore, each support column mounting hole 11 has a countersunk structure 12 on its bottom surface. The countersunk structure 12 can be either a conical countersunk hole or a cylindrical stepped hole, used to accommodate the screw head of the first screw 4. This ensures that the screw head will not protrude from the bottom surface of the tray after being locked, preventing jamming or tilting during transport in the reflow oven and guaranteeing the uniformity and flatness of the force during the PCB soldering process. By setting a countersunk structure on the bottom surface of the support column mounting hole, this invention allows the head of the screw locking the movable support column to be completely contained within the countersunk structure, preventing the screw head from protruding outwards. This ensures the overall flatness of the tray bottom surface and solves the problem of tilting and shaking caused by local protrusions during tooling placement and transport. Although some tooling on the market also has countersunk holes, they are only used for installation. However, the countersunk structure and the waist-shaped slot adjustable support system in this invention are used together to achieve free adjustment of the movable support column to adapt to irregularly shaped PCBs while simultaneously ensuring the flatness and stability of the bottom surface. The two are complementary and not isolated structures.

[0032] As a further improvement to the above technical solution, the fastener includes a first screw 4, a nut 5, a second screw 6, and a flat washer 7. The first screw 4 passes sequentially through the oblong slot 24 and the support column mounting hole 11, and then engages with the nut 5 to lock the movable support column 2 onto the tray 1. The second screw 6, together with the flat washer 7, passes through the PCB mounting hole 31 on the PCB 3 and engages with the threaded hole on the first connecting part 22, achieving a secure connection between the PCB 3 and the top of the movable support column 2.

[0033] Based on the above technical solution, this invention first secures the PCB to the top of the movable support column, and then mounts the entire assembly on a tray with high flatness. Through the fixed support of the tray and the movable support column, the deformation of the PCB during high-temperature soldering in the reflow oven can be effectively constrained, reducing PCB warpage. Simultaneously, the tray and movable support column adopt a separate structure, and the position and angle of the support column can be finely adjusted through the waist-shaped groove structure at the bottom of the support column, adapting to the mounting and fixing of PCBs with different hole spacings. This invention can adapt to PCBs of any thickness, shape, and size, offering strong versatility and eliminating the need for tooling replacement or readjustment, thus reducing manufacturing costs and changeover time.

[0034] This invention also includes a PCB assembly method using a universal conformal tooling for suppressing high-temperature warpage during PCB reflow soldering, the method comprising the following steps: S1, Pre-assembly Based on the actual mounting hole distribution on the PCB surface to be assembled, select a corresponding number of movable support columns 2, and align the slotted holes 24 of the second connecting part 23 at the bottom of each movable support column 2 with the support column mounting holes 11 on the tray 1; use the first screw 4 and nut 5 for pre-tightening assembly, and pre-tighten the movable support columns 2 onto the tray 1. In the pre-tightened state, the nut 5 is not completely locked, allowing the movable support columns 2 to move radially and rotate angularly relative to the tray 1 through the slotted holes 24, reserving adaptive adjustment margin.

[0035] S2, Assembly and Fixing Place the PCB 3 to be assembled stably on the top of each movable support column 2, aligning the mounting holes 31 on the PCB 3 with the first connecting part 22 at the top of the movable support column 2; use the second screw 6 and flat washer 7 to lock and fix the PCB 3 to the top of the movable support column 2, completing the fitting assembly of the PCB 3 and each movable support column 2, so that the PCB and the support column points correspond one by one.

[0036] S3, Locking and Molding Based on the flatness of PCB 3, the position and angle of each movable support column 2 are adjusted adaptively to ensure that the top of each movable support column 2 is fully in contact with the bottom surface of PCB 3, achieving an ideal contact state and ensuring uniform stress and flatness of the PCB surface. After adjustment, the first screw 4 and corresponding nut 5 at the bottom of tray 1 are tightened completely one by one, firmly locking all movable support columns 2 onto tray 1. This solidifies tray 1, movable support columns 2, and PCB 3 into a unified rigid support structure, completing the PCB assembly and shaping. After tightening, the screw heads of each first screw are completely retracted into the countersunk structure on the bottom surface of the tray. The bottom surface of the tray has no protruding structures, and the overall bottom surface of the fixture is flat, allowing it to be placed and transported stably and stably on the reflow oven conveyor belt, ensuring stable and reliable support during the soldering process and effectively suppressing board warping and deformation.

[0037] Existing PCB conformal fittings are mostly structurally simple and functionally fragmented. They either only provide fixed support without adjustment capabilities, or have only simple adjustment structures that cannot simultaneously ensure flatness, support rigidity, and assembly accuracy. The various structures cannot cooperate to form a complete conformal fitting system, making it difficult to simultaneously meet the production requirements of versatility, stability, and anti-warping. Therefore, this invention innovatively combines a tray, adjustable movable support columns, two-stage rigid fasteners, and a dedicated assembly method to form an integrated, collaborative conformal fitting system. This invention achieves multiple technical effects through the coordinated operation of the tray, movable support columns, and two-stage locking structure. The waist-shaped slots enable adaptive adjustment of the position and angle of the movable support columns, thus adapting to various types of irregularly shaped PCBs. The countersunk structure ensures smooth tooling transport. Multiple movable support columns form a rigid multi-point support system, preventing high-temperature thermal deformation of the PCB. Based on the conformal tooling, and with appropriate assembly methods—pre-adjustment, board loading, leveling, and locking—assembly stress can be avoided. Furthermore, simply changing the support column specifications allows for adaptation to PCBs of varying weights, achieving a universal tooling solution with multiple mutually supporting effects, which cannot be achieved by simply stacking a single structure.

[0038] The following is combined Figures 1-5 The universal conformal tooling structure described in this invention will be described in detail. This embodiment is a universal conformal tooling applied to the reflow soldering process of power module PCBs.

[0039] Example 1 This embodiment provides a universal conformal fixture for reflow soldering of power module PCBs. The fixture includes a rectangular tray 1 machined from 6061 aluminum alloy sheet. The tray 1 is 5mm thick, and both its upper and lower surfaces are precision milled, with a flatness controlled within 0.1mm. The tray has circular through holes with a diameter of 3mm machined at 10mm array intervals as support post mounting holes 11. On the bottom surface of each support post mounting hole (i.e., the side facing the worktable), a countersunk structure is machined. This countersunk structure is a standard countersunk flat-bottom hole, with a diameter larger than the head diameter of an M2.5 screw, and a depth greater than the head height of the screw, fully accommodating the screw head.

[0040] The movable support column 2 is made of 304 stainless steel. The main body 21 of the support column is a smooth cylinder with a diameter of 5.5 mm and a height of 12 mm. A 5 mm deep M2 threaded blind hole is machined at the center of the top of the main body 21, serving as the first connecting part 22 for matching and fixing the PCB 3. A rectangular flange with a length of 30 mm, a width of 7 mm, and a thickness of 2 mm is integrally formed at the bottom of the main body 21, serving as the second connecting part 23. Two waist-shaped slots 24 with a length of 9.25 mm and a width of 3 mm are symmetrically machined on the flange 23 to achieve bidirectional fine adjustment of the position and angle of the support column.

[0041] In this embodiment, the fasteners are divided into two groups. The first group of fasteners includes M2.5 pan head screws and M2.5 nuts, which are used to lock and fix the movable support column to the tray. The second group of fasteners includes M2 pan head screws and standard flat washers 7 with an outer diameter of 2mm, which are used to lock and fix the PCB to the top of the movable support column.

[0042] The specific assembly and usage process of the above-mentioned general conformal tooling is as follows: First, select six sets of movable support columns 2 according to the positions of the six mechanical mounting holes on the power PCB to be soldered (e.g., an irregularly shaped power PCB). Align the slotted holes 24 of the flange at the bottom of each movable support column 2 with the corresponding support column mounting holes 11 on the tray 1. Use M2.5 pan head screws to pass through the support column mounting holes 11 and slotted holes 24 sequentially from the bottom of the tray, and insert M2.5 nuts into the second connecting part 23 for initial tightening. During the tightening process, use the limiting groove 25 on the top surface of the flange to hold the M2.5 nuts in place to prevent the nuts from rotating with the screws. At this time, the movable support column 2 can slide and rotate within a small range.

[0043] Then, as Figure 4 As shown, place the PCB 3 to be assembled stably on the top of each movable support column 2, aligning the PCB mounting holes 31 on the PCB 3 with the M2 threaded holes at the top of the movable support columns 2. Use M2 pan head screws with flat washers to pass through the PCB mounting holes 31 and screw them into the threaded holes in sequence, completing the pre-fixed assembly of the PCB 3 and the movable support columns 2.

[0044] Next, observe and fine-tune the position and angle of each movable support column 2 on the tray 1, so that the top of each support column 2 is evenly attached to the bottom surface of the PCB 3, ensuring that the PCB as a whole is in an optimal level and stress-free flat support state. After adjustment, use a screwdriver to fully tighten the six M2.5 pan head screws on the bottom of the tray, so that the entire system (PCB-support column-tray) is solidified into a rigid whole.

[0045] After assembly, all screw heads are completely retracted into the countersunk structure 12 on the bottom of tray 1, with no protruding structures. The bottom of tray 1 is flat and can be placed stably on the reflow oven conveyor belt, ensuring stable tooling transport and uniform PCB support during high-temperature soldering, effectively suppressing PCB warping deformation at high temperatures.

[0046] Example 2 Based on Embodiment 1, a high-load adaptation solution is provided to accommodate larger and heavier high-power power PCBs. In this embodiment, the diameter of the main body 21 of the movable support column 2 is increased to 6.5mm, effectively improving the structural rigidity and load-bearing capacity of the column. Correspondingly, the first connecting part 22 at the top is replaced with an M2.5 threaded hole to meet the requirements of larger-specification fastening and ensure reliable assembly and fixation of heavy-duty PCBs. In this embodiment, the flange structure, waist-shaped slot structure, tray structure, assembly adjustment method, and locking principle of the movable support column 2 are consistent with those of Embodiment 1. The heavy-duty PCB adaptation can be achieved simply by replacing the movable support column with a different specification and size.

[0047] Therefore, it can be seen that the present invention can be flexibly adapted to various PCB products with different board sizes, different weight loads and different hole layouts by simply replacing the movable support columns of different specifications. There is no need to replace the tray body or re-open the mold and modify the board. The tooling has a wide range of adaptability and high reusability, and has strong versatility and structural scalability.

[0048] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A universal conformal fixture for suppressing high-temperature warpage during PCB reflow soldering, characterized in that, Includes a pallet (1), several separately arranged movable support columns (2), and fasteners; The tray (1) has a number of support column mounting holes (11) arranged in an array, and each support column mounting hole (11) has a countersunk structure (12) on its bottom surface. The movable support column (2) includes a support column body (21), a first connecting part (22) located at the top of the support column body (21), and a second connecting part (23) located at the bottom of the support column body (21). The second connecting part (23) is a flange, and at least one waist-shaped slot (24) is provided on the flange (23). The waist-shaped slot (24) cooperates with the support column mounting hole (11) so that the movable support column (2) can be moved and rotated relative to the tray for adjustment. The fasteners are used to lock and fix the movable support column (2) to the tray (1) and the PCB (3) to the movable support column (2).

2. The universal conformal fixture for suppressing high-temperature warpage during PCB reflow soldering according to claim 1, characterized in that, The tray (1) is an aluminum alloy flat plate formed by machining.

3. The universal conformal fixture for suppressing high-temperature warpage during PCB reflow soldering according to claim 1, characterized in that, Several support column mounting holes (11) are arranged in an array on the tray (1).

4. The universal conformal fixture for suppressing high-temperature warpage during PCB reflow soldering according to claim 1, characterized in that, The movable support column (2) is made of metal.

5. The universal conformal fixture for suppressing high-temperature warpage during PCB reflow soldering according to claim 1, characterized in that, The first connecting part (22) is a threaded hole.

6. The universal conformal fixture for suppressing high-temperature warpage during PCB reflow soldering according to claim 1, characterized in that, The countersunk structure (12) adopts either a tapered countersunk hole or a cylindrical stepped hole to accommodate the screw head.

7. The universal conformal fixture for suppressing high-temperature warpage during PCB reflow soldering according to claim 1, characterized in that, The fasteners include a first screw, a nut, a second screw, and a flat washer; The first screw (4) passes through the waist-shaped slot (24) and the support column mounting hole (11) in sequence and is then locked with the nut to lock the movable support column (2) to the tray (1). The second screw (6) is paired with a flat washer and passes through the mounting hole on the PCB (3) and engages with the threaded hole of the first connecting part (21) to achieve a tight connection between the PCB (3) and the top of the movable support column (2).

8. A PCB assembly method using a universal conformal fixture for suppressing high-temperature warpage during PCB reflow soldering, characterized in that, The method includes the following steps: S1. According to the distribution of mounting holes of the PCB to be assembled, several movable support columns (2) are aligned with the support column mounting holes on the tray (1) through the waist-shaped slot (24) of the second connecting part (23), and fasteners are used for pre-tightening and fixing, so that the position and angle of the movable support columns (2) can be adjusted relative to the tray (1). S2. Place the PCB (3) to be assembled on the top of each movable support column (2), align the mounting holes on the PCB (3) with the first connecting part (22), and lock and fix the PCB (3) on the movable support column (2) with fasteners. S3. Adjust the position and angle of each movable support column (2) so that the top of each support column (2) is in contact with the bottom surface of the PCB (3), and tighten the fasteners so that the movable support column (2) and the tray (1) are fixed together as a whole, and the PCB assembly is completed.

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