Welding tool and welding method for multi-element surface-mounted radio frequency connector

Abstract

The invention discloses a welding tool and a welding method for a multi-element surface-mounted radio frequency connector, the welding tool comprises a base, a cover plate and a mother board, the base is provided with a first limiting frame and a second limiting frame, the first limiting frame is used for placing the mother board, and the second limiting frame is used for placing the cover plate; positioning holes are formed in the cover plate, the number of the positioning holes is the same as that of the radio frequency connectors, and the positioning holes are used for limiting movement of the connector shells; a plurality of positioning columns are arranged on the cover plate and used for limiting movement of the connector surface mounting needle, each positioning hole corresponds to two positioning columns, and every two adjacent positioning columns are located on the two sides of the corresponding positioning hole; the ventilation holes of the base are formed in the side surface and the bottom surface of the base; the cover plate is provided with ventilation holes, and the ventilation holes of the cover plate are located on the periphery of the positioning hole. The temperature uniformity and the welding quality in the welding process of the multi-element surface-mounted radio frequency connector can be improved, the problems that the surface-mounted radio frequency connector is low in welding precision and poor in consistency are solved, and the manual welding production efficiency is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of microelectronic packaging, and in particular relates to a welding tool and a welding method for a multi-element surface-mount radio frequency connector. Background Art

[0002] In recent years, as radar has developed towards high integration, high performance, and miniaturization, the size of each radar subsystem has been small, the integration has been high, the interconnection methods have become more diverse, the assembly and maintenance of the subsystems have become more difficult, and the packaging and interconnection technology between radar subsystems has also faced new development needs.

[0003] System-level interconnection based on multi-element surface mount RF connectors is achieved through surface mount RF connectors and multiple ports of the subsystem, which has the advantages of simple assembly, low cost, and easy maintenance. Due to the high degree of system integration, the number of channels on a single motherboard of the subsystem is large, and the number of corresponding RF connectors is also large. The connector port is related to the transmission performance of the RF and the interconnection communication between subsystems, so the welding quality and precision of the connector are very important.

[0004] The welding technology of multi-element surface mount RF connectors has made significant progress, but the following problems still exist: (1) In actual applications, in addition to the connector, the motherboard also contains other welding components on the front and back of the motherboard. Due to factors such as component obstruction, welding tooling isolation, and uneven distribution of components, the heating rates of different areas of the motherboard are different during hot air reflow or gas phase reflow, which leads to the connector and surrounding components being prone to cold soldering or over-soldering, resulting in poor welding quality; (2) The corresponding plug-in interface positions of the multi-element surface mount RF connector are fixed. As long as one of the connectors is offset after welding, the connector array cannot be plugged and connected to the corresponding interface at the same time, which in turn causes the multi-element connector microsystem sub-array to be unable to connect to other systems. During the reflow soldering of the surface mount RF connector, due to the lack of obstructions around the connector, as well as factors such as the welding environment and solder flow, the welding accuracy is difficult to control, resulting in the connector being uncontrollably offset in any direction after welding, resulting in poor welding consistency; (3) The shell of the surface mount RF connector is cylindrical, and there are directional requirements when surface mounting. It is difficult to mark the connector shell for alignment, which is not suitable for machine automated production. However, due to the large number of connectors, manual placement and welding efficiency is low, and the accuracy of manual welding is difficult to ensure, which increases the workload of rework and further reduces production efficiency. Summary of the invention

[0005] The purpose of the present invention is to provide a welding tool and a welding method for a multi-element surface-mount RF connector, which can improve the temperature uniformity and welding quality of the welding process of the multi-element surface-mount RF connector, solve the problems of low welding accuracy and poor consistency of the surface-mount RF connector, and effectively improve the production efficiency of manual welding.

[0006] One aspect of the present invention provides a welding tool based on a multi-element surface-mount radio frequency connector, comprising a base, a cover plate and a motherboard, wherein the base is provided with a first limit frame and a second limit frame, wherein the first limit frame is used to place the motherboard, and the second limit frame is located above the first limit frame and is used to place the cover plate, wherein a soldering pad is provided on the motherboard for soldering with the connector, and the radio frequency connector comprises a connector housing and a connector surface-mount pin; The cover plate is provided with positioning holes, the number of which is the same as the number of the RF connectors, for limiting the movement of the connector housing; The cover plate is provided with a plurality of positioning posts for limiting the movement of the connector surface mount pins. Each positioning hole corresponds to two positioning posts, and two adjacent positioning posts are located on both sides of the positioning hole. The difference between the distance from the cover plate to the motherboard and the length of the positioning posts is 0.02 to 1 mm, and the difference between the distance between two adjacent positioning posts and the diameter of the connector surface mount pins is 0.02 to 1 mm. The base is provided with ventilation holes, and the ventilation holes of the base are located on the side and bottom of the base, the ventilation holes on the side are located between two adjacent RF connectors, and the ventilation holes on the bottom are located below the solder pads of the motherboard; The cover plate is provided with ventilation holes, and the ventilation holes of the cover plate are located around the positioning hole.

[0007] Preferably, the difference between the diameter of the positioning hole and the diameter of the RF connector is 0.01-1 mm.

[0008] Preferably, the single-side offset of the motherboard placed on the first limiting frame is 0.05-1 mm; the single-side offset of the cover plate placed on the second limiting frame is 0.05-1 mm.

[0009] Preferably, the base and the cover are made of one or more of aluminum, aluminum alloy and graphite.

[0010] Another aspect of the present invention provides a method for welding a multi-element surface mount radio frequency connector, using the above-mentioned welding tool to weld the multi-element surface mount radio frequency connector, the method comprising: A layer of solder paste is printed on the pad surface of the motherboard by using steel screen printing; Placing the motherboard in the first limiting frame of the base; Placing the cover plate in the second limiting frame of the base; Place the RF connector on the corresponding pad of the motherboard through the positioning hole on the cover; Put the placed connector and the welding tooling into the reflow oven for reflow soldering; After the reflow soldering is completed, the soldering tooling is removed to obtain a soldered multi-element surface-mount RF connector.

[0011] Preferably, the solder paste is one of SAC305, SnPb37, and SnBi58.

[0012] The welding tooling and welding method of the multi-element surface-mount RF connector according to the above aspects of the present invention can improve the temperature uniformity and welding quality of the welding process of the multi-element surface-mount RF connector, solve the problems of low welding accuracy and poor consistency of the surface-mount RF connector, and effectively improve the manual welding production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings used in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work: Figure 1 A schematic structural diagram of a welding tool for a multi-element surface mount radio frequency connector according to an embodiment of the present invention; Figure 2 A top view of a base of a welding tool according to an embodiment of the present invention; Figure 3 A top view of a cover plate of a welding tool according to an embodiment of the present invention; Figure 4 The figure is a side cross-sectional view of a welding tool according to an embodiment of the present invention.

[0014] Among them, 1-base, 2-first limiting frame, 3-second limiting frame, 4-side ventilation holes of base, 5-bottom ventilation holes of base, 6-cover, 7-positioning holes, 8-positioning columns, 9-motherboard, 10-connector pads, 11-RF connector, A-positioning hole diameter, B-RF connector diameter, C-distance from cover to motherboard, D-length of positioning column, E-distance between two adjacent positioning columns, F-diameter of RF connector surface mount pin, G-unilateral offset of motherboard placed in the first limiting frame, H-unilateral offset of cover placed in the second limiting frame. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] An embodiment of the present invention provides a welding tool for a multi-element surface mount radio frequency connector. Figure 1 The figure is a schematic diagram of the structure of a welding tool for a multi-element surface mount RF connector according to an embodiment of the present invention. Figure 1 In the embodiment shown, the multi-element surface mount RF connector is a 64-element surface mount RF connector. Figure 1-Figure 3 As shown, the welding tool of the embodiment of the present invention includes a base 1, a cover plate 6 and a motherboard 9. The base 1 is provided with a first limit frame 2 and a second limit frame 3, the first limit frame 2 is used to place the motherboard 9, and the second limit frame 3 is located above the first limit frame 2 and is used to place the cover plate 6. The motherboard 9 is provided with a soldering pad 10 for soldering with a radio frequency connector 11, and the radio frequency connector 11 includes a connector housing and a connector surface mount pin.

[0017] like Figure 4 As shown, the unilateral offset of the motherboard 9 placed on the first limiting frame 2 is G, and the value range of G is 0.05-1mm; the unilateral offset of the cover plate 6 placed on the second limiting frame 3 is H, and the value range of H is 0.05-1mm. Preferably, the unilateral offset G is 0.05mm, and the unilateral offset H is 0.05mm.

[0018] The cover plate 6 is provided with a plurality of positioning holes 7, the number of which is the same as the number of the surface mount RF connectors 11, for accommodating the surface mount RF connectors 11. Figure 4 As shown, the difference between the diameter A of the positioning hole 7 and the diameter B of the surface mount RF connector 11 is I=AB, and the value range of I is 0.01-1 mm. The difference only needs to meet the mounting accuracy requirement, and preferably, the difference I is 0.05 mm.

[0019] A plurality of positioning posts 8 are provided on the cover plate 6, and each positioning hole 7 corresponds to two positioning posts 8, and the two positioning posts 8 are located on both sides of the positioning hole 7. Figure 4 As shown, the difference between the distance C from the cover plate 6 to the motherboard 9 and the length D of the positioning column 8 is J=CD, and the value range of J is 0.02-1mm; the difference between the distance E between two adjacent positioning columns and the diameter F of the RF connector surface-mounted pin is K=EF, and the value range of K is 0.02-1mm. Preferably, the difference J between the distance C from the cover plate 6 to the motherboard 9 and the length D of the positioning column 8 is 0.4mm; the difference K between the distance E between two adjacent positioning columns 8 and the diameter F of the RF connector surface-mounted pin is 0.05mm.

[0020] In one embodiment, the base 1 is provided with ventilation holes, which are located on the side and bottom of the base 1, the side ventilation holes 4 are located between two adjacent connectors 11, and the bottom ventilation holes 5 are located below the pads 10 of the connectors 11 on the motherboard 9. The cover plate 6 is provided with ventilation holes, which are located around the positioning holes 7 of the cover plate 6.

[0021] In one embodiment, the base 1 and the cover plate 6 are made of one or more of aluminum, aluminum alloy, and graphite. Preferably, the base 1 and the cover plate 6 are made of aluminum alloy.

[0022] An embodiment of the present invention further provides a welding method for a multi-element surface mount radio frequency connector, which uses the welding tool of the above embodiment to weld the multi-element surface mount radio frequency connector, comprising the following steps: 1) Printing a layer of solder paste on the surface of the pad 10 of the motherboard 9 by means of steel screen printing; 2) placing the motherboard 9 in the first limiting frame 2 of the base 1 with the printed solder paste facing upwards; 3) Place the cover plate 6 in the second limiting frame 3 of the base 1, with the side with the positioning column 8 facing downward; 4) placing the connector 11 on the corresponding pad 10 of the motherboard 9 through the positioning hole 7 on the cover plate 6. Specifically, the connector 11 can be clamped with tweezers and placed into the positioning hole 7 on the cover plate 6 in sequence, so that the connector 11 is aligned and in contact with the corresponding pad 10 on the motherboard 9; 5) Put the placed connector and the welding tooling into the reflow oven for reflow soldering, and take it out after reflow is completed; 6) When the surface temperature of the tooling drops to room temperature, remove the welding tooling to obtain a welded multi-element surface-mount RF connector.

[0023] In one embodiment, the solder paste is one of SAC305, SnPb37, and SnBi58. Preferably, the solder paste is SAC305.

[0024] In summary, the welding tooling and welding method of the multi-element surface-mount RF connector of the embodiment of the present invention are as follows: 1) ventilation holes are provided on the base and the cover plate to improve temperature uniformity; 2) positioning holes and positioning columns are provided on the cover plate to limit the movement of the connector; 3) the limit frame and the positioning holes can realize precise alignment of the connector, thereby improving the temperature uniformity and welding quality of the connector welding process, solving the problems of low welding precision and poor consistency of surface-mount RF connectors, and effectively improving the production efficiency of manual welding.

[0025] Specifically, the welding tool and welding method of the multi-element surface mount RF connector according to the embodiment of the present invention produce the following beneficial effects: 1. The present invention has ventilation holes on the side and bottom of the base 1 of the welding tool and the surface of the cover plate 6. During the reflow soldering process, heat sources such as hot air or gas phase liquid vapor can be gathered from the ventilation holes to the surface of the motherboard 9, fully contacting the connector 11, and heating the connector 11 from all directions to ensure a consistent heating rate, so that the solder can quickly reach the welding temperature, ensure that the solder is fully melted, and achieve high-quality welding; 2. The present invention controls the external dimensions and relative positions of the first limiting frame 2, the second limiting frame 3, the cover plate 6, and the positioning hole 7 to ensure that when the connector 11 is placed through the positioning hole 7, the connector 11 can be accurately aligned with the pad 10 of the motherboard 9 to ensure welding consistency. In addition, the positioning hole 7 is set on a cover plate 6, which can limit the overall offset error of the connector and further improve the welding consistency of the connector. 3. The present invention sets a positioning hole 7 and a positioning column 8 of the connector 11 on the cover plate 6. The positioning column 8 can limit the movement of the connector surface-mounted pin, and the positioning hole 7 can limit the movement of the connector housing, thereby limiting the displacement of the connector as a whole. In the production process, it is only necessary to place the connector directly on the motherboard 9 pad 10 through the positioning hole 7 without manual alignment, thereby improving manual production efficiency. The size and height of the positioning column 8 are further set so that the positioning column 8 can limit the movement of the connector surface-mounted pin while not contacting the solder paste, and will not affect the flow of solder, thereby ensuring the welding quality and welding reliability.

[0026] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A welding tool based on a multi-element surface mount radio frequency connector, characterized in that: It includes a base, a cover plate and a motherboard, the base is provided with a first limit frame and a second limit frame, the first limit frame is used to place the motherboard, the second limit frame is located above the first limit frame and is used to place the cover plate, the motherboard is provided with a soldering pad for soldering with the connector, and the RF connector includes a connector housing and a connector surface mount pin; The cover plate is provided with positioning holes, the number of which is the same as the number of the RF connectors, for limiting the movement of the connector housing; The cover plate is provided with a plurality of positioning posts for limiting the movement of the connector surface mount pins. Each positioning hole corresponds to two positioning posts, and two adjacent positioning posts are located on both sides of the positioning hole. The difference between the distance from the cover plate to the motherboard and the length of the positioning posts is 0.02 to 1 mm, and the difference between the distance between two adjacent positioning posts and the diameter of the connector surface mount pins is 0.02 to 1 mm. The base is provided with ventilation holes, and the ventilation holes of the base are located on the side and bottom of the base, the ventilation holes on the side are located between two adjacent RF connectors, and the ventilation holes on the bottom are located below the solder pads of the motherboard; The cover plate is provided with ventilation holes, and the ventilation holes of the cover plate are located around the positioning hole.

2. The welding tool according to claim 1, characterized in that: The difference between the diameter of the positioning hole and the diameter of the radio frequency connector is 0.01-1 mm.

3. The welding tool according to claim 1 or 2, characterized in that: The single-side offset of the motherboard placed on the first limiting frame is 0.05-1 mm; the single-side offset of the cover plate placed on the second limiting frame is 0.05-1 mm.

4. The welding tool according to claim 1 or 2, characterized in that: The base and the cover are made of one or more of aluminum, aluminum alloy and graphite.

5. A welding method for a multi-element surface mount radio frequency connector, characterized in that: Using the welding tool described in any one of claims 1 to 4 to weld a multi-element surface mount radio frequency connector, the method comprising: A layer of solder paste is printed on the pad surface of the motherboard by using steel screen printing; Placing the motherboard in the first limiting frame of the base; Placing the cover plate in the second limiting frame of the base; Place the RF connector on the corresponding pad of the motherboard through the positioning hole on the cover; Put the placed connector and the welding tooling into the reflow oven for reflow soldering; After the reflow soldering is completed, the soldering tooling is removed to obtain a soldered multi-element surface-mount RF connector.

6. The welding method according to claim 5, characterized in that: The solder paste is one of SAC305, SnPb37 and SnBi58.

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