Welding method and welding temperature control tool for high-speed connector

Abstract

The application discloses a welding method and a welding temperature control tool for a high-speed connector, and comprises the following steps: S1, laser printing and resistance soldering treatment is performed on each contact piece of the high-speed connector to form a resistance soldering layer; S2, the total solder volume required for forming a qualified welding point of the high-speed connector and the corresponding optimal solder paste volume are calculated, and the opening size of a steel mesh used for printing the solder paste is designed according to the calculation result; S3, the steel mesh made according to S2 is placed on a printed board, the steel mesh openings are used to print on the printed board to form a plurality of solder pastes, and then each contact piece of the high-speed connector is attached to each solder paste of the printed board; S4, the welding temperature control tool is placed on the printed board of the high-speed connector which has been attached, and the whole assembly comprising the welding temperature control tool, the high-speed connector and the printed board is put into a reflow oven for reflow soldering. The application can solve the problems of virtual welding and short circuit caused by wicking effect in the welding process of the high-speed connector, and improve the assembly qualification rate and process stability.

Description

Technical Field

[0001] This invention relates to the field of electronic assembly technology, and in particular to a welding method for high-speed connectors and a welding temperature control fixture. Background Technology

[0002] With the miniaturization and multifunctional integration of electronic devices, high-density printed circuit board (PCB) assemblies and board-level interconnect structures are widely used. Surface mount high-speed connectors, as interconnect devices enabling high-speed, multi-channel signal transmission, are increasingly widely applied. Unlike the solder joint structure of general connectors, the solder joint structure of high-speed connectors consists of two parts: contact leads and solder pads. The solder pads are typically riveted to the contact leads using cold stamping. This structure results in extremely poor process adaptability for high-speed connectors during soldering. Once soldering defects occur, such as cold solder joints or short circuits, they cannot be repaired by ball repositioning; replacement is the only option. Therefore, the first-pass yield rate of high-speed connectors is particularly important.

[0003] When high-speed connectors are soldered using conventional SMT (Surface Mount Technology), solder paste is first printed onto the pads of the printed circuit board (PCB), then the high-speed connectors are mounted, and finally, the PCB with the high-speed connectors is placed in a reflow oven for soldering. During reflow, the solder pads pre-placed on the contacts and the solder paste printed on the pads melt together to form solder joints. However, in actual production, defects such as cold solder joints and short circuits are very common, with cold solder joints accounting for more than 90% of all defects. The main reason for cold solder joints is that the formation of solder joints in high-speed connectors is affected by both the wetting force of the solder in its molten state (pointing towards the solder tip) and its own gravity (pointing towards the pad). If the wetting force is greater than the gravity, the solder will move upwards along the contacts, producing a phenomenon commonly known as "wicking," resulting in insufficient solder at the pads and forming open-circuit cold solder joints.

[0004] Currently, the industry primarily improves welding quality by optimizing reflow soldering process parameters, employing nitrogen protection, increasing stencil thickness, and using welding counterweights. However, these methods fall under the category of passive suppression or parameter adjustment and cannot fundamentally solve the wicking problem caused by structural characteristics and uneven temperature field distribution, resulting in low first-pass yield and stability. Furthermore, the varying oxidation states of connector solder pads across different batches further complicate process control. Therefore, a systematic solution is urgently needed, addressing device structure, solder supply, and welding processes collaboratively to improve the assembly pass rate and process stability of high-speed connectors.

[0005] The statements herein provide only background information in relation to the present invention and do not necessarily constitute prior art. Summary of the Invention

[0006] The purpose of this invention is to provide a welding method and welding temperature control fixture for high-speed connectors, so as to solve the problems of poor soldering and short circuit caused by the core suction effect during the welding process of high-speed connectors in the prior art, and improve the first-time assembly pass rate and process stability.

[0007] To achieve the above objectives, the present invention provides a soldering method for a high-speed connector, used to solder various contacts on a high-speed connector to a printed circuit board. The soldering method includes the following steps: Step S1: Laser engraving of solder resist is performed on each contact on the high-speed connector, that is, by focusing a laser beam on a specific area on the surface of each contact to form a solder resist layer. Step S2: Calculate the total solder volume and the corresponding optimal solder paste volume required for the high-speed connector to form qualified solder joints, and design the opening size of the stencil for printing solder paste based on the calculation results. Step S3: Place the stencil made according to step S2 onto the printed circuit board, print multiple solder pastes on the printed circuit board through the openings in the stencil, and then mount each contact of the high-speed connector onto each solder paste on the printed circuit board. Step S4: Place the soldering temperature control fixture on the printed circuit board of the mounted high-speed connector, and place the entire assembly, including the soldering temperature control fixture, the high-speed connector, and the printed circuit board, into a reflow oven for reflow soldering; wherein, before placing the entire assembly into the reflow oven, the spacing between the bottom of each side plate of the soldering temperature control fixture and the printed circuit board is adjusted to ensure that the temperature rise rate of the solder joints at different positions of the high-speed connector is consistent.

[0008] Optionally, in step S1, the end of the contact is provided with a pre-placed solder pad, which forms a solder pad opening after covering the end of the contact. The specific area on the surface of the contact is the surface area of ​​the contact 2mm away from the solder pad opening.

[0009] Optionally, step S2 includes the following steps: S2.1, Based on the wetting angle between the solder and the contact, establish a qualified solder joint model, and calculate the total solder volume V required to form a qualified solder joint based on this model. total ; S2.2, Measure the volume V of the pre-placed solder pads on the contacts of the high-speed connector. pre And calculate the optimal solder paste volume V'; S2.3, Design the stencil aperture size based on the optimal solder paste volume V'.

[0010] Optionally, the wetting angle is in the range of 20°-40°.

[0011] Optionally, the formula for calculating the optimal solder paste volume V' is: V' = Vtotal -V pre .

[0012] Optionally, step S2.3 includes the following steps: S2.3.1, Calculate the required solder paste volume V for stencil printing based on the solder paste volume and its shrinkage rate ε. paste ; S2.3.2, determine the thickness d of the steel mesh, and calculate the opening radius r of the steel mesh.

[0013] Optionally, the volume V of the printed solder paste paste The calculation formula is: V paste = V' / (1-ε).

[0014] Optionally, the volume V of the printed solder paste paste The relationship between V and the opening radius r of the steel mesh is: paste = aπr 2 d; where a is the printing correction factor and d is the thickness of the stencil.

[0015] The present invention also provides a welding temperature control fixture for implementing the aforementioned welding method, the welding temperature control fixture comprising: The support structure includes a first support structure and a second support structure that are spaced apart, the distance between the two support structures being greater than the lateral dimension of the high-speed connector; the bottoms of the first support structure and the second support structure abut against the upper surface of the printed circuit board. The side panel includes two opposing first side panels and two opposing second side panels, which are arranged in a frame structure and are slidably disposed around the first support structure and the second support structure. A top cover is disposed above the first support structure and the second support structure, and the two ends of the top cover are fixedly connected to the top of the first support structure and the second support structure, respectively.

[0016] Optionally, each of the first side plates is provided with a first sliding groove at both ends along its thickness direction, and each of the second side plates is provided with a second sliding groove at both ends along its thickness direction. The first support structure and the second support structure are provided with corresponding threaded holes on each side wall near the first side plate and the second side plate; Each of the first side plates can slide up and down, so that the first sliding grooves at both ends of the first side plate can move relative to the corresponding threaded holes on the first and second support structures at both ends. Each of the second side plates can slide up and down, so that the second sliding grooves at both ends of the second side plate can move relative to the corresponding threaded holes on the first support structure / second support structure.

[0017] In summary, compared with the prior art, the present invention has the following beneficial effects: 1. The welding method of the present invention introduces a laser-engraved solder resist method to form a low surface energy solder resist layer on the surface above the solder pad assembly position of the contact component. This physically blocks the path of the solder climbing upward along the contact component, fundamentally avoiding the cold solder joint caused by the "core suction" effect.

[0018] 2. This invention utilizes reverse engineering design to establish a three-dimensional model of qualified solder joints in high-speed connectors, enabling precise calculation of solder volume and accurate design of stencil openings. This avoids welding defects caused by excessive or insufficient solder, ensuring the consistency of solder joint quality.

[0019] 3. The present invention designs a dedicated reflow soldering temperature control fixture, which adjusts the temperature rise rate of the solder joints on the side and bottom of the connector to keep the overall temperature rise rate of the connector consistent, ensuring that the flux works at the same time and avoiding poor wetting or core suction caused by local overheating or temperature lag.

[0020] 4. This invention organically combines laser resist soldering, precise material feeding, and temperature field equalization control to form a complete and systematic solution. The synergistic effect fundamentally solves the problems of core suction and cold solder joints in high-speed connector soldering, and significantly improves the first-pass yield (up to 99% or more) and process stability. Attached Figure Description

[0021] Figure 1 A flowchart illustrating the welding method for a high-speed connector provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of laser-engraved solder resist processing provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a three-dimensional model of the solder joint of the present invention; Figure 4 This is a schematic diagram of the welding temperature control fixture provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the steel mesh opening structure provided in an embodiment of the present invention; Figure 6 A schematic diagram of the temperature profile for reflow soldering provided in an embodiment of the present invention; Figure 7 This diagram illustrates the positional relationship between the welding temperature control fixture and the high-speed connector provided in an embodiment of the present invention. Detailed Implementation

[0022] The following will be combined with the appendix Figures 1-7The present invention will be further described in detail through preferred embodiments. The advantages and features of the present invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, only for the purpose of conveniently and clearly illustrating the embodiments of the present invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of the present invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives achieved by the present invention, should still fall within the scope of the technical content disclosed in the present invention.

[0023] like Figure 2 As shown, the high-speed connector 12 is an electronic device with multiple contacts 10. It realizes the transmission of high-speed signals from the high-speed connector 12 to the printed circuit board 7 by soldering the contacts 10 (pins) to the printed circuit board 7.

[0024] like Figure 1 As shown, this invention takes the FMC (FPGA mezzanine card) high-speed connector as an example and provides a soldering method for high-speed connectors. This soldering method effectively solves the problems of cold solder joints and short circuits caused by the "wicking" effect during the soldering process through the synergistic effect of three core elements: "physical blocking," "precise supply," and "temperature equalization." The soldering method includes the following steps: Step S1: Laser engraving solder resist treatment is performed on each contact 10 on the high-speed connector 12. That is, by focusing a laser beam on a specific area on the surface of each contact 10, the surface microstructure and chemical state are changed, thereby forming a solder resist layer 11 with a specific surface energy on the surface of each contact 10. The end of the contact 10 is provided with a pre-placed solder pad 9, which forms a solder pad opening 901 after covering the contact. A specific area on the surface of the contact 10 is the surface area of ​​the contact 10 located 2 mm away from the solder pad opening 901. That is, the laser beam is focused on the location where the solder resist layer 11 is formed.

[0025] like Figure 2As shown, the contacts 10 of the high-speed connector 12 undergo laser-etched solder resist pretreatment, i.e., surface modification of the contacts 10 using a laser beam, rather than material removal. Specifically, when the laser beam is focused on the surface area of ​​the contacts 10 at a distance of 2 mm from the solder pad opening 901, the microstructure and chemical state of the metal surface in this area are changed by adjusting laser parameters (such as power, scanning speed, or dwell time), thereby forming a solder resist layer 11 with low surface energy. The function of this solder resist layer 11 is to prevent molten solder from continuing to climb upwards along the contacts 10 during subsequent reflow soldering, thereby physically cutting off the "wicking" path.

[0026] It should be noted that the laser parameters for this step are not strictly limited in this invention, as long as they can achieve surface modification and form an effective solder resist layer 11.

[0027] Step S2: Based on the reverse engineering design approach, calculate the total solder volume required for the high-speed connector 12 to form qualified solder joints and the corresponding additional solder volume (i.e., the optimal solder paste 8 volume), and design the opening size of the stencil for printing solder paste based on the calculation results. Specifically, step S2 includes: S2.1, Establish a qualified solder joint model; Based on the wetting angle between the solder and contact 10, the ideal morphology of a qualified solder joint is determined to be a convex shape. In this embodiment, the wetting angle range is 20°-40°. Specifically, the wetting angle θ between the solder and contact 10 is set to a typical value, for example, θ≈30°, and then the following is established: Figure 3 The model shows a three-dimensional model of a single qualified solder joint, and the total solder volume V required to form this qualified solder joint is calculated from the model. total .

[0028] In a specific embodiment of the present invention, the total solder volume V required to form the qualified solder joint total It is 0.176mm 3 .

[0029] S2.2, calculate the required solder volume V' (i.e., the optimal solder paste volume). like Figure 2 As shown, taking the connection between a contact 10 on the high-speed connector 12 and the printed circuit board 7 as an example, before soldering, solder paste 8 needs to be printed on the printed circuit board 7. The volume of the solder paste 8 is the volume of solder to be added, and the volume of solder to be added is obtained by subtracting the volume of the pre-placed solder 9 at the end of the contact 10 from the total solder volume required to form a qualified solder joint.

[0030] The volume V of the pre-placed solder pad 9 on the contact 10 of the high-speed connector 12 is measured.pre Therefore, the required additional solder volume V' is: V' = V total -V pre .

[0031] In a specific embodiment of the present invention, the volume V of the pre-placed solder pad 9 pre It is 0.146 mm. 3 The required solder volume V' is 0.03 mm. 3 .

[0032] S2.3, Design the opening dimensions of the steel mesh, which include: S2.3.1, Based on the volume of solder paste 8 and the shrinkage rate ε, calculate the required volume of solder paste V for printing via stencil printing. paste V paste = V' / (1-ε).

[0033] Specifically, solder paste 8 undergoes volume shrinkage during reflow soldering. In this embodiment, the solder paste 8 used is solder paste (e.g., OL-107E, Sn63Pb37), with a volume shrinkage rate of approximately 60%. Based on this, the required printed solder paste volume V can be calculated. paste It is 0.075 mm. 3 .

[0034] S2.3.2, determine the steel mesh thickness d, and calculate the steel mesh opening radius r; the calculation formula is: V paste =aπr 2 d; In the formula, considering the losses that occur during the actual printing process, a printing correction coefficient a is introduced, a=1.3.

[0035] In a specific embodiment of the present invention, the thickness d of the steel mesh is 0.13 mm, and the opening radius r of the steel mesh is approximately 0.375 mm, that is, the opening diameter of the steel mesh is 0.75 mm.

[0036] like Figure 5 As shown, a steel mesh with an opening diameter of 0.75 mm is designed in this way; in addition, based on the spacing of the multiple contacts 10 provided on the high-speed connector 12, the distance between adjacent openings of the steel mesh is set to 1.27 mm.

[0037] Step S3: Place the stencil made in step S2 onto the printed circuit board 7, and print multiple solder pastes 8 on the printed circuit board 7 through the openings in the stencil. Then, attach each contact 10 of the high-speed connector 12 to each solder paste 8 on the printed circuit board 7. Specifically, multiple solder pastes 8 are formed by printing on the printed circuit board 7 using a fully automatic solder paste printing equipment. After printing, the quality of the solder paste printing can be inspected using an automatic optical inspection equipment to ensure that there are no defects such as bridging or insufficient solder. Subsequently, multiple contacts 10 on the high-speed connector 12 that have been pre-processed in step S1 are aligned and mounted onto the corresponding solder pastes 8 using a fully automatic placement equipment, thereby mounting the high-speed connector 12 onto the printed circuit board 7.

[0038] Step S4: Place the soldering temperature control fixture 13 on the printed circuit board 7 of the mounted high-speed connector 12, and place the entire assembly including the soldering temperature control fixture 13, the high-speed connector 12 and the printed circuit board 7 into a reflow oven for reflow soldering; wherein, before placing the entire assembly into the reflow oven, the spacing between the bottom of each side plate of the soldering temperature control fixture 13 and the printed circuit board 7 is adjusted to ensure that the temperature rise rate of the solder joints at different positions of the high-speed connector 12 is consistent.

[0039] Specifically, such as Figure 7 As shown, the soldering temperature control fixture 13 is placed on the printed circuit board 7 with the high-speed connector 12 already mounted. Then, the entire assembly, including the soldering temperature control fixture 13, the high-speed connector 12, and the printed circuit board 7, is placed in a reflow oven for soldering. In this embodiment, the temperature settings for each zone of the reflow oven can be referenced... Figure 6 The temperature curve shown ensures that the solder paste melts fully and has good wetting properties, thereby ensuring the soldering pass rate and stability between each contact 10 of the high-speed connector 12 and the printed circuit board 7.

[0040] Figure 6 As an example, the temperature profile is set as follows: preheating zone (140℃-150℃-160℃), holding zone (160℃-180℃-210℃), reflow zone (210℃-250℃-240℃-235℃), and cooling zone (235℃-100℃-60℃-40℃). The reflow oven is equipped with a chain mechanism and a moving plate. The entire assembly, including the welding temperature control fixture 13, the high-speed connector 12, and the printed circuit board 7, is placed on the moving plate inside the reflow oven and is sequentially transported through the preheating zone, holding zone, reflow zone, and cooling zone by the chain mechanism to complete the reflow soldering process. The chain mechanism travels at a speed of 80cm / min, meaning that the entire assembly passes through each temperature zone sequentially at a speed of 80cm / min.

[0041] Among them, such as Figure 4 As shown, the welding temperature control fixture 13 used in step S4 includes: a support structure 4, various side plates and a top cover 3. The welding temperature control fixture 13 forms a semi-enclosed structure with an open bottom by connecting the various side plates and the top cover 3 to the support structure 4.

[0042] The support structure 4 includes a first support structure 41 and a second support structure 42 that are spaced apart, and the distance between the two support structures is greater than the lateral dimension of the high-speed connector 12; the bottoms of the first support structure 41 and the second support structure 42 abut against the upper surface of the printed circuit board 7.

[0043] The side plate includes two opposing first side plates 1 and two opposing second side plates 2; the first side plates 1 and the second side plates 2 form a 90° angle and are arranged in a frame structure, and are slidably disposed around the first support structure 41 and the second support structure 42; specifically, one of the first side plates 1 is directly opposite the first side wall of the first support structure 41; the other first side plate 1 is directly opposite the first side wall of the second support structure 42; one of the second side plates 2 is directly opposite the plane formed by the second side wall of the first support structure 41 and the second side wall of the second support structure 42; the other second side plate 2 is directly opposite the plane formed by the third side wall of the first support structure 41 and the third side wall of the second support structure 42.

[0044] The top cover 3 is disposed above the first support structure 41 and the second support structure 42. The two ends of the top cover 3 are fixedly connected to the top of the first support structure 41 and the second support structure 42 respectively by the first fastener 5.

[0045] Each of the first side plates 1 has a first sliding groove 110 at both ends along its thickness direction, and each of the second side plates 2 has a second sliding groove 210 at both ends along its thickness direction. The first support structure 41 and the second support structure 42 have corresponding threaded holes near the side walls of the first side plate 1 and the second side plate 2 (i.e., the first side wall, second side wall, and third side wall of the first support structure 41, and the first side wall, second side wall, and third side wall of the second support structure 42). Taking the first side plate 1 as an example, one end of the second fastener 6 is inserted into the first sliding groove 110 on the first side plate 1 and then screwed in. In the corresponding threaded hole, the other end is tightened by a nut to fix one end of the first side plate 1 to the first support structure 41 (or the second support structure 42); then, in the same way, the other end of the first side plate 1 is fixed to the first support structure 41 (or the second support structure 42) by the second fastener 6; taking the second side plate 1 on one side as an example, one end of the second fastener 6 is passed through the second sliding groove 210 of the second side plate 2, and then screwed into the corresponding threaded hole, and the other end of the second fastener 6 is tightened by a nut to fix one end of the second side plate 2 to the first support structure 41, and the other end of the second side plate 2 is fixed to the second support structure 42 in the same way. When it is necessary to adjust the hot air convection intensity on the side and bottom of the high-speed connector 12, each screw cap can be loosened in sequence to move each first side plate 1 and second side plate 2 upward (that is, the first sliding groove 110 on the first side plate 1 slides upward relative to the second fastener 6 passing through it, and the second sliding groove 210 on the second side plate 2 slides upward relative to the second fastener 6 passing through it). When it is moved to the preset height position, the screw cap is tightened to fasten the first side plate 1 and the second side plate 2 to the support structure 4. However, at this time, the bottom of the first side plate 1 and the second side plate 2 is separated from the printed circuit board 7 by a certain distance, which can effectively control the hot air convection intensity entering the side and bottom of the high-speed connector 12, thereby ensuring that the temperature rise rate of the solder joints on the side and bottom of the high-speed connector 12 is consistent.

[0046] Furthermore, before the entire assembly including the welding temperature control fixture 13, the high-speed connector 12, and the printed circuit board 7 is placed into the reflow oven, the two opposing first side plates 1 are moved upward to a preset height relative to the first support structure 41 and the second support structure 42, and then fixed into the threaded holes of the corresponding support structure 4 by the second fastener 6 passing through the first sliding groove 110 on the first side plate 1, thereby fixing the first side plate 1 to the first support structure 41 and the second support structure 42; similarly, the two opposing second side plates 2 are moved upward to the same preset height relative to the first support structure 41 and the second support structure 42, and then fixed into the threaded holes of the corresponding support structure 4 by the second fastener 6 passing through the second sliding groove 210 on the second side plate 2, thereby fixing the second side plate 2 to the first support structure 41 and the second support structure 42. Thus, the bottoms of each of the first side plates 1 and the second side plates 2 are spaced a certain distance from the printed circuit board 7. After the entire assembly is placed in the reflow oven, the hot air convection intensity of each area of ​​the high-speed connector 12 can be adjusted, thereby adjusting the temperature rise rate of the solder joints at different positions of the high-speed connector 12 and making them consistent.

[0047] In a specific embodiment of the present invention, the first fastener 5 is a screw, and the second fastener 6 is an adjusting bolt.

[0048] Preferably, the welding temperature control fixture 13 is made of high-temperature resistant epoxy fiberglass material.

[0049] The working principle of the welding temperature control fixture 13 is that by adjusting the opening height of the first side plate 1 and the second side plate 2, the intensity of hot air convection entering the side and bottom of the high-speed connector 12 can be controlled. Experiments show that without using the welding temperature control fixture 13, the temperature rise rate of the solder joints on the side of the high-speed connector 12 is about 0.8℃ / s, while that on the bottom is about 0.7℃ / s. This temperature difference is an important factor that exacerbates the "wicking" effect. After using the welding temperature control fixture 13 of the present invention, by adjusting the first side plate 1 and the second side plate 2, the temperature rise rate of the solder joints on the side and bottom of the high-speed connector 12 can be stabilized at 0.7℃ / s, and the peak temperature can be controlled within the target range of 214℃~220℃. After welding, X-ray inspection and microscopic examination of the solder joints show that the solder joints are fully formed, the interface is well bonded, and there are no defects such as cold solder joints or short circuits. Batch verification shows that the welding method of the present invention can stably improve the first-time welding pass rate of the high-speed connector 12 to over 99%, demonstrating excellent process stability and adaptability to the oxidation differences of different batches of solder pieces.

[0050] In summary, the welding method and welding temperature control fixture for high-speed connectors provided by this invention, through the synergistic effect of laser-engraved solder resist treatment, precise material feeding based on reverse engineering, and temperature field equalization control by a dedicated temperature control fixture, fundamentally solves the problems of core suction, poor soldering, and short circuits in the assembly and welding process of high-speed connectors, and has extremely high stability and process adaptability.

[0051] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0052] In the description of this invention, it should be understood that the terms "center," "height," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0053] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0055] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for soldering a high-speed connector, used to solder various contacts on a high-speed connector to a printed circuit board, characterized in that, Includes the following steps: Step S1: Laser engraving of solder resist is performed on each contact on the high-speed connector, that is, by focusing a laser beam on a specific area on the surface of each contact to form a solder resist layer. Step S2: Calculate the total solder volume and the corresponding optimal solder paste volume required for the high-speed connector to form qualified solder joints, and design the opening size of the stencil for printing solder paste based on the calculation results. Step S3: Place the stencil made according to step S2 onto the printed circuit board, print multiple solder pastes on the printed circuit board through the openings in the stencil, and then mount each contact of the high-speed connector onto each solder paste on the printed circuit board. Step S4: Place the soldering temperature control fixture on the printed circuit board of the mounted high-speed connector, and place the entire assembly, including the soldering temperature control fixture, the high-speed connector, and the printed circuit board, into a reflow oven for reflow soldering; wherein, before placing the entire assembly into the reflow oven, the spacing between the bottom of each side plate of the soldering temperature control fixture and the printed circuit board is adjusted to ensure that the temperature rise rate of the solder joints at different positions of the high-speed connector is consistent.

2. The welding method as described in claim 1, characterized in that, In step S1, the end of the contact is provided with a pre-placed solder pad. After the pre-placed solder pad covers the end of the contact, it forms a solder pad opening. The specific area on the surface of the contact is the surface area of ​​the contact 2mm away from the solder pad opening.

3. The welding method as described in claim 1, characterized in that, Step S2 includes the following steps: S2.1, Based on the wetting angle between the solder and the contact, establish a qualified solder joint model, and calculate the total solder volume V required to form a qualified solder joint based on this model. total ; S2.2, Measure the volume V of the pre-placed solder pads on the contacts of the high-speed connector. pre And calculate the optimal solder paste volume V'; S2.3, Design the stencil aperture size based on the optimal solder paste volume V'.

4. The welding method as described in claim 3, characterized in that, The wetting angle ranges from 20° to 40°.

5. The welding method as described in claim 3, characterized in that, The formula for calculating the optimal solder paste volume V' is: V' = V total -V pre .

6. The welding method as described in claim 5, characterized in that, Step S2.3 includes the following steps: S2.3.1, Calculate the required solder paste volume V for stencil printing based on the solder paste volume and its shrinkage rate ε. paste ; S2.3.2, determine the thickness d of the steel mesh, and calculate the opening radius r of the steel mesh.

7. The welding method as described in claim 6, characterized in that, Printed solder paste volume V paste The calculation formula is: V paste =V' / (1-ε).

8. The welding method as described in claim 6, characterized in that, The volume of the printed solder paste V paste The relationship between V and the opening radius r of the steel mesh is: paste = aπr 2 d; where a is the printing correction factor and d is the thickness of the stencil.

9. A welding temperature control fixture for implementing the welding method as described in any one of claims 1-8, characterized in that, The welding temperature control fixture includes: The support structure includes a first support structure and a second support structure that are spaced apart, the distance between the two support structures being greater than the lateral dimension of the high-speed connector; the bottoms of the first support structure and the second support structure abut against the upper surface of the printed circuit board. The side panel includes two opposing first side panels and two opposing second side panels, which are arranged in a frame structure and are slidably disposed around the first support structure and the second support structure. A top cover is disposed above the first support structure and the second support structure, and the two ends of the top cover are fixedly connected to the top of the first support structure and the second support structure, respectively.

10. The welding temperature control fixture as described in claim 9, characterized in that, Each of the first side plates has a first sliding groove at both ends along its thickness direction, and each of the second side plates has a second sliding groove at both ends along its thickness direction. The first support structure and the second support structure are provided with corresponding threaded holes on each side wall near the first side plate and the second side plate; Each of the first side plates can slide up and down, so that the first sliding grooves at both ends of the first side plate can move relative to the corresponding threaded holes on the first and second support structures at both ends. Each of the second side plates can slide up and down, so that the second sliding grooves at both ends of the second side plate can move relative to the corresponding threaded holes on the first support structure / second support structure.

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