Tin guide type SMP connector welding structure and use method thereof

Abstract

The invention relates to the field of electronic installation and connection processes, in particular to a tin guide type SMP connector welding structure and a using method thereof.The tin guide type SMP connector welding structure is characterized in that an installation hole consistent with an SMP connector in appearance is formed in a shell of an SMP device to be installed, and a first solder groove is formed in the end face of the installation hole at a first step of the SMP connector; a second solder groove is formed in the junction of the second step and the first step of the SMP connector, a solder adding groove is formed in the end of the first solder groove, and a plurality of rapid solder guiding grooves used for solder circulation are formed between the first solder preset groove and the second solder preset groove. During use, molten soldering tin at the soldering flux adding groove flows from the first soldering flux groove to the second soldering flux groove through the rapid tin guide groove. When the SMP connector is installed and used, welding flux is added from the outside through the welding flux adding groove, the firm installation of the SMP connector can be realized by the molten welding flux through the rapid tin guide groove, the installation process is simple and efficient, and air tightness can be realized.

Description

Technical Field

[0001] The present invention relates to the field of electronic assembly technology and is applied to the field of radio frequency filter circuit components, and in particular to a tin-conducting SMP connector welding structure and a use method thereof. Background Art

[0002] In the field of electronic manufacturing, SMP connectors play the role of connecting or disconnecting coaxial cables, microstrip circuits, and transmitting signals in microwave circuits. They are important functional elements for realizing electrical connections and signal transmission between modules, components, systems and subsystems, etc., and are widely used in many scenarios such as satellites, radars, navigation and communications.

[0003] The welding defects of SMP connectors not only affect the sealing performance of the product, but also directly affect the electrical performance, such as high-frequency transmission performance. SMP and the shell are usually assembled through a reflow soldering process using a pre-set solder ring, which places high demands on the shell mounting hole processing and reflow soldering tooling. When the gap between the shell mounting hole and the SMP connector is too small, the solder is not wetted enough, resulting in welding voids; if the gap is too large, the assembly accuracy is insufficient, which can easily cause problems such as tin spreading and short circuits. In addition, due to its small size and stepped structure, the installation accuracy of the SMP connector is low in the existing tooling fixtures and installation methods, and the efficiency is not high. The welding quality also has problems such as poor welding, tin spreading and short circuits, and it is difficult to ensure consistency during batch welding.

[0004] In addition, in highly demanding application scenarios, the product structure is often required to be sealed after installation, which poses a greater challenge to the installation process of the SMP connector. Summary of the invention

[0005] In order to solve the shortcomings of the traditional structure, such as no tin-filling position, poor appearance consistency and high dependence on operators, the present invention proposes a tin-conducting SMP connector welding structure for the welding and installation of a two-stage structure SMP connector, wherein a mounting hole consistent with the appearance of the SMP connector is opened on the shell of the SMP device to be installed, a first solder groove is arranged on the end face of the mounting hole at the first step of the SMP connector, a second solder groove is arranged at the junction of the second step of the SMP connector and the first step, and a solder adding groove is arranged at the end of the first solder groove, and a plurality of quick tin-conducting grooves for solder circulation are arranged between the first solder pre-groove and the second solder pre-groove. When in use, the melted solder at the solder adding groove flows from the first solder groove to the second solder groove through the quick tin-conducting groove.

[0006] Further, a diameter of the second solder groove is larger than a diameter of the second step of the SMP and smaller than a diameter of the first step of the SMP.

[0007] Furthermore, the total depth of the first solder groove and the solder adding groove is 1 / 3 to 1 / 5 of the height of the first step of the SMP connector.

[0008] Further, the first solder groove is larger than a diameter of the first step of the SMP.

[0009] Furthermore, the depth of the second solder groove is 1 / 5 to 1 / 8 of the height of the second step of the SMP connector.

[0010] Furthermore, the solder adding groove is funnel-shaped, and the end with a smaller cross-section is connected to the first solder groove, and the closer to the solder adding end, the larger the cross-section.

[0011] Furthermore, 3 to 6 quick tin guide grooves are evenly arranged around the mounting hole.

[0012] Furthermore, the quick tin-conducting groove is arranged along the wall of the mounting hole, and the groove body thereof is semicircular.

[0013] The present invention also provides a method for using a tin-conducting SMP welding structure, which specifically comprises the following steps:

[0014] A layer of flux is applied to the surface of the SMP connector that contacts the welding structure, and then the SMP connector is pushed into the soldering structure of the tin-conducting SMP connector, so that the lower surface of the first step of the SMP connector is flush with the end surface of the second step mounting hole;

[0015] Place the soldering structure with the SMP connector on a hot plate at 140°C for full preheating for 3 to 5 minutes; then move it to a hot plate at 230°C for heating, and add solder wire to the solder adding tank after the shell temperature is uniform. After the solder wire melts, it flows from the solder adding tank to the first solder tank, and then flows from the first solder tank to the second solder tank through the tin guide tank;

[0016] Keep adding solder until the gap between the SMP connector and the soldered structure disappears completely;

[0017] Cool it to room temperature and use tweezers to hold the connector in place during the cooling process to prevent the SMP connector from floating out of the housing.

[0018] Furthermore, before placing the SMP into the tin-conducting SMP welding structure, the surface and the mounting holes of the SMP are cleaned with alcohol cotton dipped in anhydrous ethanol. Compared with the traditional SMP connector welding structure, the present invention has the following significant advantages:

[0019] 1. The housing mounting hole of the present invention matches the SMP. When installing, the SMP is pushed to the bottom of the mounting hole to achieve positioning. The positioning is simple and easy to operate, and the requirements for the machining accuracy of the housing mounting hole are relatively low.

[0020] 2. Two preset solder tanks are set in the welding structure, and one of the solder tanks is located at the outermost side. Its solder status is visible, which is convenient for technicians to dynamically replenish solder according to the status of the outermost solder tank. There is no need to customize additional tin rings and tin sheets, which reduces the preparation cost;

[0021] 3. During the soldering process, solder can be added from the outside and flow between the two solder tanks through the fast soldering tank, avoiding the problem of solder shrinkage and voids. The double solder tank and fast soldering tank design and dynamic tin filling installation method can achieve better structural sealing.

[0022] 4. No additional clamping tools are required during the welding process, and the installation work can be completed directly on the hot plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a tin-conducting SMP welding structure of the present invention;

[0024] Figure 2 It is a schematic diagram of a general SMP structure in the prior art;

[0025] Figure 3 A schematic cross-sectional view of a tin-conducting SMP welding structure of the present invention at the guide groove position after SMP is installed;

[0026] Among them, 1. solder adding tank; 2. first solder tank; 3. quick tin guide tank; 4. second solder tank; 5. hole wall matching with the first step; 6. hole wall matching with the second step. DETAILED DESCRIPTION

[0027] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, they all belong to the scope of protection of the present invention.

[0028] The present invention proposes a tin-conducting SMP welding structure for welding and installing a two-step structure SMP connector. The structure is characterized in that a mounting hole consistent with the appearance of the SMP connector is opened on a shell of a SMP device to be installed, a first solder groove is arranged on the end face of the mounting hole at the first step of the SMP connector, a second solder groove is arranged at the junction of the second step and the first step of the SMP connector, and a solder adding groove is arranged at the end of the first solder groove. A plurality of rapid tin-conducting grooves for solder circulation are arranged between the first solder pre-groove and the second solder pre-groove. When the SMP connector is installed on a hot plate, the melted solder at the solder adding groove flows from the first solder groove to the second solder groove through the rapid tin-conducting groove.

[0029] In the art, the structure of a general SMP connector is as follows: Figure 2As shown, it includes a first step and a second step, and a lead is led out from the axis of the second step. The height of the first step of SMP is A, and the cross-sectional diameter of the first step is The height of the second step of SMP is CA, and the cross-sectional diameter of the first step is

[0030] like Figure 1 This embodiment provides a tin-conducting SMP welding structure, in which a mounting hole matching the SMP structure is provided. Specifically, the mounting hole matches the two step structures of the SMP structure. Figure 2 Take the SMP device as an example, Figure 3 , the upper surface of the second step of the SMP device is flush with the top of the welding structure of the present invention, that is, Figure 3 On the right end face, a second solder groove is provided inside the mounting hole and at the junction between the first step and the second step of the SMP device. The groove is annular, and the inner diameter of the ring is larger than the diameter of the second step, and the outer diameter of the ring is smaller than the inner diameter of the first step. A first solder groove is provided on the end face of the mounting hole at the first step of the SMP connector, and a solder adding groove is provided at the end of the first solder groove. In the actual setting process, the solder adding groove is funnel-shaped, and the end with a smaller cross-section is connected to the first solder groove, and the closer to the solder adding end, the larger the cross-section.

[0031] The welding structure of the present invention is as follows Figure 1 As shown, it mainly includes a through hole structure matching the shape of the first step and the second step of the SMP, wherein the hole wall 5 matching the first step and the hole wall 6 matching the second step are the main through structures of the present invention. In this through hole structure, first, a hole is opened at the connection between the first step and the second step. Figure 2 The second solder tank 4 shown is an annular structure, which is connected to the first solder tank through a fast tin guide tank 3. The first solder tank is set at 1 / 4 to 3 / 5 of the first step. A solder pre-set tank 1 is also opened at the end of the first solder tank. When the SMP device is installed in the welding structure, the cross-sectional result is as follows Figure 3 .

[0032] This embodiment also provides a specific size setting of a tin-conducting SMP soldering structure. In the actual implementation process, the outer surface of the SMP device is used as a part of the first solder groove, and the mounting hole is actually a through hole matching the SMP device. The first solder groove, the second solder groove, the rapid tin-conducting groove and the solder adding groove are arranged on the hole wall, wherein:

[0033] In the mounting hole opened on the housing of the SMP device to be mounted, the diameter adapted to the first step mounting position is set to In order to adapt to the height of the first step, the depth of the mounting hole is set to A+0.2mm;

[0034] The inner diameter of the first solder groove is larger than the diameter of the first step of the SMP, and the depth of the first solder groove is 1 / 5 to 1 / 8 of the height of the second step of the SMP connector. As an optional implementation, the inner diameter of the annular groove structure of the first solder groove is generally larger than B and its outer diameter is smaller than B+0.5mm. The minimum diameter of the solder adding groove is equal to the outer diameter of the first solder groove, and the solder adding groove is convenient for adding solder;

[0035] The inner diameter of the second solder groove is larger than the diameter of the second step, and the outer diameter is smaller than the diameter of the first step. The depth of the second solder groove is 1 / 5 to 1 / 8 of the height of the second step of the SMP connector. This depth ensures that the solder flowing into the fast guide groove can be accommodated, and the first step can be blocked and limited.

[0036] A plurality of quick tin guide grooves for solder circulation are arranged between the first solder groove and the second solder groove. The quick tin guide grooves are evenly distributed on the wall surface of the mounting hole between the first solder groove and the second solder groove in the circumferential direction. The number of the quick tin guide grooves is generally 3 to 6, and there are 4 in the attached drawings of this embodiment. The cross section of the guide groove is generally semicircular, and the diameter T of the semicircular opening is 0.2-0.3mm. The quick tin guide groove includes two parts in the specific implementation. The first part is provided with a semicircular groove along the wall surface of the inner diameter of the first solder groove and extends in the axial direction. Since there is a certain difference in diameter between the first solder groove and the second solder, the second part near the second step is perpendicular to the first part and extends to the axis to form an "L" shape;

[0037] In the above dimensional design, the aperture processing accuracy is a positive tolerance, and the tolerance is [0, 0.1] mm; the length direction accuracy is a positive tolerance, and the tolerance is [0, 0.05] mm.

[0038] The welding structure of the present invention increases the redundant space of solder at the outer end of the shell through the design of the solder adding groove, which solves the defect of the traditional tin-conducting structure without tin-adding position; at the same time, it solves the shortcomings of solder overflow and large appearance difference during welding; the design of the second solder groove forms a second layer of solder ring on the SMP step surface to further meet the air tightness requirements of the SMP and the shell, and solves various welding defects such as high solder void rate on the transition surface and short circuit between the air cavity and the inner conductor; the design of the quick tin-conducting groove locally expands the solder flow channel on the basis of not changing the gap between the shell and the SMP as a whole, thereby ensuring the sufficiency of the second layer of solder.

[0039] As an embodiment, a method for using a tin-conducting SMP welding structure of the present invention specifically comprises the following steps:

[0040] First, check whether there are burrs or other excess materials on the SMP mounting holes of the shell after nickel-gold electroplating, and then clean them with anhydrous ethanol and alcohol cotton;

[0041] Use a brush to evenly apply a thin layer of liquid flux on the surface of the SMP outer conductor. Place the SMP area with a length of C in the welding structure;

[0042] Put the processed SMP into the housing installation hole with tweezers, and hold the housing firmly with tweezers;

[0043] Place the soldering structure with the SMP connector on a hot plate at 140°C for sufficient preheating for 3 to 5 minutes; then move it to a hot plate 2 at 230°C for heating. After the shell temperature is uniform, add solder wire to the solder adding tank. After the solder wire melts, it flows from the solder adding tank to the first solder tank, and then flows from the first solder tank to the second solder tank through the tin guide tank; continue to add solder until the gap between the SMP connector and the shell mounting hole completely disappears. This part is judged based on the experience of technicians in this field whether the gap completely disappears. Generally, the solder in the first solder tank is in a rounded and full state. The solder will shrink during the cooling process. The ideal state is that the first solder tank is just filled after shrinkage. Generally, a slight shrinkage can be considered qualified. If there is more shrinkage, additional tin replenishment operation can be performed;

[0044] Cool to room temperature and use tweezers to hold the connector in place during the cooling process to prevent the connector from floating out of the housing.

[0045] After completing the above steps, put the product in the cleaning agent, soak it for 30 minutes, remove the flux residue and bake it in a 60℃ oven for 10 minutes to complete the assembly. During the actual operation, the technician visually inspects the welding quality of the first solder bath, requiring the solder to be round, full and continuous. If it does not meet the standard, it should be re-tinned and re-soldered on the heating table.

[0046] In the description of the present invention, it is necessary to understand that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "outside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0047] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "rotation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0048] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A tin-conducting SMP welding structure, used for welding and installing a two-stage SMP connector, characterized in that: A mounting hole consistent with the appearance of the SMP connector is opened on the shell of the SMP device to be installed, a first solder groove is set on the end face of the mounting hole at the first step of the SMP connector, a second solder groove is set at the junction of the second step of the SMP connector and the first step, and a solder adding groove is set at the end of the first solder groove, and a plurality of rapid tin guiding grooves for solder circulation are set between the first solder pre-groove and the second solder pre-groove. When in use, the melted solder at the solder adding groove flows from the first solder groove to the second solder groove through the rapid tin guiding groove.

2. The tin-conducting SMP connector welding structure according to claim 1, characterized in that: The diameter of the second solder groove is larger than the diameter of the second step of the SMP and smaller than the diameter of the first step of the SMP.

3. The tin-conducting SMP connector welding structure according to claim 1, characterized in that: The total depth of the first solder groove and the solder adding groove is 1 / 3 to 1 / 5 of the height of the first step of the SMP connector.

4. The tin-conducting SMP connector welding structure according to claim 1, characterized in that: The first solder groove is larger than a diameter of the first step of the SMP.

5. The tin-conducting SMP connector welding structure according to claim 1, characterized in that: The depth of the second solder groove is 1 / 5 to 1 / 8 of the height of the second step of the SMP connector.

6. The tin-conducting SMP connector welding structure according to claim 1, characterized in that: The solder adding groove is funnel-shaped, and the end with a smaller cross section is connected to the first solder groove, and the cross section becomes larger as it is closer to the solder adding end.

7. The tin-conducting SMP connector welding structure according to claim 1, characterized in that: 3 to 6 quick tin guide grooves are evenly arranged around the mounting hole.

8. The tin-conducting SMP connector welding structure according to claim 1, characterized in that: The quick tin guide groove is arranged along the hole wall of the installation hole, and the groove body thereof is semicircular.

9. A method for using a tin-conducting SMP welding structure, characterized in that: Using the tin-conducting SMP connector welding structure of claim 1 to weld the SMP connector specifically comprises the following steps: A layer of flux is applied to the surface of the SMP connector that contacts the welding structure, and then the SMP connector is pushed into the soldering structure of the tin-conducting SMP connector, so that the lower surface of the first step of the SMP connector is flush with the end surface of the second step mounting hole; Place the soldering structure with the SMP connector on a hot plate at 140°C for full preheating for 3 to 5 minutes; then move it to a hot plate at 230°C for heating, and add solder wire to the solder adding tank after the shell temperature is uniform. After the solder wire melts, it flows from the solder adding tank to the first solder tank, and then flows from the first solder tank to the second solder tank through the tin guide tank; Keep adding solder until the gap between the SMP connector and the soldered structure disappears completely; Cool it to room temperature and use tweezers to hold the connector in place during the cooling process to prevent the SMP connector from floating out of the housing.

10. The method for using the tin-conducting SMP connector welding structure according to claim 8, characterized in that: Before placing the SMP into the tin-conducting SMP welding structure, use alcohol cotton dipped in anhydrous ethanol to clean its surface and mounting holes.

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