A circuit board placement process with a rapid die change structure

Abstract

The present invention relates to the field of circuit board patch technology, and discloses a circuit board patch process with a rapid mold change structure, including S1, material preparation, according to the circuit board design requirements, preparing the corresponding circuit board, surface mount components, solder paste, steel mesh and other auxiliary materials; S2, solder paste printing, placing the circuit board on the solder paste printer platform, pouring an appropriate amount of solder paste on the steel mesh, using a scraper to evenly scrape the solder paste across the steel mesh at a certain speed and pressure, so that the solder paste is printed on the pads of the circuit board through the openings of the steel mesh. The circuit board patch process with a rapid mold change structure can effectively solve the problem in the prior art that the replacement requirements of the steel mesh are high, and external auxiliary tools need to be used for installation to ensure that the steel mesh is accurately aligned with the pad position of the circuit board. The operation is relatively cumbersome, and improper operation will cause deviations in the solder paste printing position, affecting the accuracy and reliability of subsequent component welding.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board patch technology, and in particular to a circuit board patch process with a rapid die change structure. Background Art

[0002] The circuit board patch process refers to a series of process flows based on printed circuit boards. It is currently the most popular technology and process in the electronic assembly industry. Operators use circuit board patch templates to accurately print solder paste onto the pads of the circuit board. The patch mechanism uses an optical recognition system to identify the marking points and components on the circuit board, and then accurately places the electronic components on the pads printed with solder paste.

[0003] The PCB patch template, or stencil, is designed and manufactured based on the PCB's pad layout. When patching PCBs of other specifications, a matching stencil must be replaced. Because stencil replacement is demanding and requires external tools to install, ensuring the stencil is accurately aligned with the PCB's pads, the process is cumbersome. Improper operation can lead to deviations in solder paste printing, affecting the accuracy and reliability of subsequent component soldering. Summary of the Invention

[0004] Technical problems solved

[0005] In response to the above-mentioned shortcomings of the prior art, the present invention provides a circuit board patch process with a quick mold change structure, which can effectively solve the problems in the prior art, such as high requirements for steel mesh replacement and the need for external auxiliary tools for installation, thereby ensuring that the steel mesh is accurately aligned with the pad position of the circuit board, and the operation is relatively cumbersome. Improper operation may cause deviations in the solder paste printing position, affecting the accuracy and reliability of subsequent component welding.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] The present invention provides a circuit board patch process with a rapid mold change structure, comprising:

[0008] S1. Material preparation: prepare the corresponding circuit boards, surface mount components, solder paste, steel mesh and other auxiliary materials according to the circuit board design requirements;

[0009] S2. Solder paste printing: Place the circuit board on the solder paste printer platform, pour an appropriate amount of solder paste on the steel mesh, and use a scraper to evenly scrape the solder paste across the steel mesh at a certain speed and pressure, so that the solder paste passes through the openings of the steel mesh and is printed on the pads of the circuit board;

[0010] S3, SPI inspection, using high-precision SPI inspection equipment to perform three-dimensional inspection on the printed solder paste to check whether the volume, height and offset parameters of the solder paste meet the requirements;

[0011] S4, component placement, put the prepared components into the material station of the placement machine, and the placement machine places them on the corresponding position of the circuit board according to the pre-programmed program;

[0012] S5, AOI inspection: After the components are mounted, AOI inspection equipment is used to inspect the circuit board after mounting through high-resolution cameras and image processing technology;

[0013] S6, reflow soldering, the circuit board after patching is sent into the reflow soldering furnace for soldering, so that the solder paste melts, and the molten solder forms a good solder connection between the component pins and the circuit board pads. After cooling, the components can be soldered on the circuit board;

[0014] S7, functional test, perform functional test on the soldered circuit board to verify whether it meets the product design requirements;

[0015] S8. Cleaning and packaging: Use ultrasonic cleaning or solvent cleaning to remove the flux, oil and dust remaining on the surface of the circuit board after welding. Pack the cleaned and inspected qualified circuit boards and take protective measures against moisture, static electricity and collision.

[0016] The solder paste printer in S2 includes a housing, a frame is detachably mounted in the space enclosed by the housing, and a steel grid is fixedly connected to the inner side of the frame;

[0017] A steel mesh body, the steel mesh body being arranged on the surface of the steel mesh frame, and a calibration piece for adjusting the position of the steel mesh body being provided on the interface between the steel mesh body and the steel mesh frame;

[0018] Among them, the calibration part includes a plug-in rod, which is provided with four and distributed in an array along the central circumference of the steel mesh body. The steel mesh frame is fixedly connected to a plug-in socket through an installation cavity opened inside it, and a plug-in groove is opened on the upper surface of the plug-in socket, and the diameter of the plug-in groove is larger than the diameter of the plug-in rod.

[0019] Furthermore, the frame is slidably connected to a solder paste feeding assembly for printing solder paste via an electric slide assembly provided at its upper portion, and the frame is slidably connected to a loading assembly for conveying circuit boards via an electric slide assembly provided at its lower portion.

[0020] Furthermore, the steel mesh main body includes a protective frame and a steel mesh body. The protective frame is detachable, and a slot for installing the steel mesh body is opened in the protective frame.

[0021] Furthermore, a conical surface is provided on the upper portion of the plug-in slot, a through hole is provided on the bottom end of the plug-in seat, an annular groove is provided on the inner wall of the through hole, and a clamping block is provided on the inner wall of the annular groove.

[0022] Furthermore, the plug-in rod is detachably mounted on the lower surface of the guard frame, a cavity is provided inside the plug-in rod, a movable plate is slidably connected in the cavity, and the movable plate is connected to the upper surface of the cavity through a round wire spring arranged on its top, the cavity is slidably connected to a guide rod fixed to the lower surface of the movable plate through a slot hole provided on its lower surface, and an electromagnetic block is fixedly connected to the lower surface of the guide rod.

[0023] Furthermore, the plug-in rod is slidably connected to a correction plate that fits with the inner wall of the plug-in slot through a mounting groove provided on its circumferential outer surface; the correction plate is fixedly connected to a movable rod on the side away from the inner wall of the plug-in slot, and the movable rod passes through the circumferential outer surface of the plug-in rod and extends into the cavity; the movable rod is provided with an inclined surface at one end away from the correction plate, and the bottom end of the movable plate is fixedly connected to an inclined plate that slides with the inclined surface of the movable rod.

[0024] Furthermore, an open slot is provided inside the guide rod, and a locking mechanism for limiting the position of the guide rod is provided in the open slot;

[0025] The locking mechanism includes a push rod, which is fixedly connected in the installation cavity and arranged directly below the socket. A conical block is provided on the top of the push rod, and the upper surface of the push rod is magnetically connected to the electromagnetic block.

[0026] Furthermore, the open groove is slidably connected to a locking wedge through a sliding hole opened on its inner wall, and the locking wedge is provided in plurality and distributed in an array along the central circumference of the guide rod, and the locking wedge is connected to the inner wall of the sliding hole through an elastic member provided on its lower surface, and the locking wedge is provided with a groove fit with the block on the side away from the guide rod, and the locking wedge is provided with a conical surface fit with the conical block on the side away from the groove.

[0027] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0028] The present invention is provided with a calibration part. The guide rod will slowly move downward under the action of the electromagnetic block. The movable plate cooperates with the inclined plate and the inclined surface of the movable rod to drive the correction plate connected to the movable rod to move synchronously. One of the correction plates will first approach and contact the inner wall of the plug-in slot. The correction plate will give the guide rod a reaction force pointing to the center of the plug-in slot. This reaction force will continuously adjust the position of the plug-in rod, so that the plug-in rod gradually moves toward the center position of the plug-in slot until the central axis of the plug-in rod coincides with the central axis of the plug-in slot. The central axes of the four plug-in rods coincide with the central axes of the plug-in socket respectively, thereby ensuring that the steel mesh body is in the center position of the steel mesh frame, avoiding the inability to accurately align the steel mesh body with the welding position of the circuit board during installation, resulting in the solder paste printing position offset, affecting the subsequent welding quality of electronic components. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0030] Figure 1 This is a flow chart of a circuit board patch process according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the three-dimensional structure of an embodiment of the present invention;

[0032] Figure 3 Schematic diagram of the three-dimensional structure of the rack according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the three-dimensional separation structure of the steel mesh main body according to an embodiment of the present invention;

[0034] Figure 5 Schematic diagram of the three-dimensional structure of the steel grid and the steel mesh body according to an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the three-dimensional separation structure of the plug rod and the plug socket according to an embodiment of the present invention;

[0036] Figure 7 Schematic diagram of the three-dimensional structure of the correction plate, guide rod and movable plate according to an embodiment of the present invention;

[0037] Figure 8 Schematic diagram of the three-dimensional structure of the locking wedge according to an embodiment of the present invention;

[0038] Figure 9 This is a schematic cross-sectional view of a socket according to an embodiment of the present invention;

[0039] Figure 10 For the embodiment of the present invention Figure 9 A schematic diagram of the structure at center A;

[0040] Figure 11 Schematic diagram of the structure of the three-dimensional state transformation of the correction plate according to an embodiment of the present invention.

[0041] The numbers in the figure represent: 1. casing; 11. frame; 12. steel mesh frame; 121. mounting cavity; 13. solder paste feeding assembly; 14. loading assembly; 2. steel mesh body; 21. calibration piece; 211. plug-in rod; 2111. cavity; 2112. movable plate; 2113. guide rod; 2114. electromagnetic block; 2115. correction plate; 2116. movable rod; 2117. inclined plate; 2118. opening slot; 2119. locking mechanism; 21191. push rod; 21192. locking wedge; 21193. card slot; 212. socket; 2121. plug-in slot; 2122. through hole; 2123. ring groove; 2124. card block; 22. guard frame; 23. steel mesh body; 24. notch. DETAILED DESCRIPTION

[0042] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. 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 making any creative efforts shall fall within the scope of protection of the present invention.

[0043] The present invention will be further described below with reference to the embodiments.

[0044] Example:

[0045] See also Figure 2-Figure 11 The present invention provides a technical solution: a circuit board patch process with a rapid mold change structure, comprising:

[0046] S1. Material preparation: prepare the corresponding circuit boards, surface mount components, solder paste, steel mesh and other auxiliary materials according to the circuit board design requirements;

[0047] S2. Solder paste printing: Place the circuit board on the solder paste printer platform, pour an appropriate amount of solder paste on the steel mesh, and use a scraper to evenly scrape the solder paste across the steel mesh at a certain speed and pressure, so that the solder paste passes through the openings of the steel mesh and is printed on the pads of the circuit board;

[0048] S3, SPI inspection, using high-precision SPI inspection equipment to perform three-dimensional inspection on the printed solder paste to check whether the volume, height and offset parameters of the solder paste meet the requirements;

[0049] S4, component placement, put the prepared components into the material station of the placement machine, and the placement machine places them on the corresponding position of the circuit board according to the pre-programmed program;

[0050] S5, AOI inspection: After the components are mounted, AOI inspection equipment is used to inspect the circuit board after mounting through high-resolution cameras and image processing technology;

[0051] S6, reflow soldering, the circuit board after patching is sent into the reflow soldering furnace for soldering, so that the solder paste melts, and the molten solder forms a good solder connection between the component pins and the circuit board pads. After cooling, the components can be soldered on the circuit board;

[0052] S7, functional test, perform functional test on the soldered circuit board to verify whether it meets the product design requirements;

[0053] S8. Cleaning and packaging: Use ultrasonic cleaning or solvent cleaning to remove the flux, oil and dust remaining on the surface of the circuit board after welding. Pack the cleaned and inspected qualified circuit boards and take protective measures against moisture, static electricity and collision.

[0054] The solder paste printer in S2 includes a housing 1, a frame 11 is detachably mounted in the space enclosed by the housing 1, and a steel grid 12 is fixedly connected to the inner side of the frame 11;

[0055] The steel mesh body 2 is provided on the surface of the steel mesh frame 12. The joint surface between the steel mesh body 2 and the steel mesh frame 12 is provided with a calibration piece 21 for adjusting the position of the steel mesh body 2.

[0056] Among them, the calibration part 21 includes a plug-in rod 211, four of which are distributed in an array along the central circumference of the steel mesh body 2. The steel mesh frame 12 is fixedly connected to the plug-in seat 212 through the installation cavity 121 opened inside it, and the upper surface of the plug-in seat 212 is provided with a plug-in groove 2121, and the diameter of the plug-in groove 2121 is larger than the diameter of the plug-in rod 211.

[0057] The frame 11 is slidably connected to a solder paste feeding assembly 13 for printing solder paste via an electric slide assembly provided at the upper portion thereof, and the frame 11 is slidably connected to a loading assembly 14 for conveying circuit boards via an electric slide assembly provided at the lower portion thereof.

[0058] The steel mesh main body 2 includes a protective frame 22 and a steel mesh body 23 . The protective frame 22 is detachable and has a slot 24 formed therein for mounting the steel mesh body 23 .

[0059] A conical surface is provided on the upper portion of the plug slot 2121 , a through hole 2122 is provided at the bottom end of the plug seat 212 , an annular groove 2123 is provided on the inner wall of the through hole 2122 , and a clamping block 2124 is provided on the inner wall of the annular groove 2123 .

[0060] The plug-in rod 211 is detachably mounted on the lower surface of the protective frame 22. A cavity 2111 is provided inside the plug-in rod 211. A movable plate 2112 is slidably connected to the cavity 2111, and the movable plate 2112 is connected to the upper surface of the cavity 2111 through a round wire spring arranged on the top thereof. The cavity 2111 is slidably connected to a guide rod 2113 fixed to the lower surface of the movable plate 2112 through a slot hole provided on its lower surface, and an electromagnetic block 2114 is fixedly connected to the lower surface of the guide rod 2113.

[0061] The plug-in rod 211 is slidably connected to a correction plate 2115 that fits the inner wall of the plug-in slot 2121 through an installation groove provided on its outer circumferential surface. The correction plate 2115 is fixedly connected to a movable rod 2116 on the side away from the inner wall of the plug-in slot 2121, and the movable rod 2116 passes through the outer circumferential surface of the plug-in rod 211 and extends into the cavity 2111. The movable rod 2116 is provided with an inclined surface on the end away from the correction plate 2115, and the bottom end of the movable plate 2112 is fixedly connected to an inclined plate 2117 that slides with the inclined surface of the movable rod 2116.

[0062] An opening slot 2118 is formed inside the guide rod 2113, and a locking mechanism 2119 is provided in the opening slot 2118 for limiting the position of the guide rod 2113;

[0063] The locking mechanism 2119 includes a push rod 21191, which is fixedly connected to the installation cavity 121. The push rod 21191 is arranged directly below the socket 212. A conical block is provided on the top of the push rod 21191. The upper surface of the push rod 21191 is magnetically connected to the electromagnetic block 2114.

[0064] The open groove 2118 is slidably connected to a locking wedge 21192 through a sliding hole opened on its inner wall, and the locking wedge 21192 is provided in plurality and distributed in an array along the central circumference of the guide rod 2113. The locking wedge 21192 is connected to the inner wall of the sliding hole through an elastic member arranged on its lower surface. The locking wedge 21192 is provided with a groove 21193 that fits with the block 2124 on the side away from the guide rod 2113, and a conical surface that fits with the conical block on the side away from the groove 21193.

[0065] The principle and advantages of the PCB SMT process with a quick die change structure:

[0066] During the actual operation, the operator will install the steel mesh body 2 with the specifications required for solder paste printing of the circuit board to be processed. First, the operator aligns the plug-in rod 211 at the lower part of the steel mesh body 2 with the plug-in slot 2121 on the steel mesh frame 12 and places it (placed according to the installation marks on the steel mesh body 2 and the steel mesh frame 12). When the plug-in rod 211 enters the plug-in slot 2121, the plug-in rod 211 will be randomly located in the plug-in slot 2121 (the diameter of the plug-in slot 2121 is larger than the plug-in rod 211), thereby causing the center position of the steel mesh body 2 to be offset from the center position of the steel mesh frame 12. At this time, the electromagnetic block 2114 at the lower part of the guide rod 2113 will start working, and an adsorption force will be generated between it and the top rod 21191, thereby realizing the movement of the guide rod 2113 toward the top rod 21191 (the diameter of the slot hole is smaller than the diameter of the through hole 2122. When the plug-in rod 211 is in the plug-in slot 2121, the bottom end of the plug-in slot 2121 will not block the slot hole, thereby preventing the guide rod 2113 from extending out of the slot hole).

[0067] The adsorption force of the electromagnetic block 2114 causes the guide rod 2113 to move slowly downward in the cavity 2111 of the plug-in rod 211, and the movable plate 2112 will move synchronously with the guide rod 2113. Since the movable plate 2112 contacts the inclined surface of the movable rod 2116 through the inclined plate 2117, the inclined plate 2117 will squeeze the movable rod 2116, thereby driving the correction plate 2115 connected to the movable rod 2116 to move synchronously. Since the connecting rod 211 is randomly positioned within the connecting slot 2121, one correction plate 2115 will always approach and contact the inner wall of the connecting slot 2121 first. After this correction plate 2115 contacts the inner wall of the connecting slot 2121, as the movable rod 2116 continues to move, the correction plate 2115 will exert a reaction force on the guide rod 2113 directed toward the center of the connecting slot 2121. This reaction force will continuously adjust the position of the connecting rod 211, causing the connecting rod 211 to gradually move toward the center of the connecting slot 2121. As the guide rod 2113 continues to move and the correction plate 2115 continuously adjusts the position of the connecting rod 211, the other correction plates 2115 will gradually contact the inner wall of the connecting hole and exert force. Multiple correction plates 2115 apply force pointing to the center to the plug-in rod 211 from different directions, continuously correcting the position deviation of the plug-in rod 211, and finally making the central axis of the plug-in rod 211 completely coincide with the central axis of the plug-in slot 2121. The central axes of the four plug-in rods 211 and the plug-in slots 2121 all coincide, thereby realizing the precise positioning of the steel mesh body 2 on the steel mesh frame 12.

[0068] It is worth noting that a conical surface is provided on the upper part of the plug-in slot 2121, which plays the role of initial guidance. When the plug-in rod 211 approaches the plug-in slot 2121, the conical surface can guide the plug-in rod 211 to roughly align with the center of the plug-in slot 2121, making it easier for the plug-in rod 211 to enter the plug-in hole, laying the foundation for subsequent precise positioning, and achieving rough positioning to a certain extent. The number of correction plates 2115 can be set according to specific installation requirements, and three are selected here.

[0069] After the steel mesh body 2 is calibrated, the guide rod 2113 has not yet contacted the push rod 21191. Under the suction force of the electromagnetic block 2114, the guide rod 2113 continues to move toward the push rod 21191. When the conical block on the push rod 21191 enters the opening groove 2118, the conical block contacts and squeezes the inclined surface of the locking wedge 21192. At this time, the locking wedge 21192 moves outward until it enters the annular groove 2123. At the same time, the groove 21193 at the end of the locking wedge 21192 engages with the block 2124 in the annular groove 2123, thereby limiting the position of the plug-in rod 211. In addition, the guide rod 2113, in cooperation with the electromagnetic block 2114, fits against the surface of the push rod 21191, thereby completing the installation and fixation of the steel mesh body 2 on the steel mesh frame 12.

[0070] When it is necessary to replace the steel mesh body 2 with a different specification, the operator controls the direction of the current inside the electromagnetic block 2114 to generate a mutually repulsive force between the electromagnetic block 2114 and the surface of the top rod 21191, and then the guide rod 2113 will move away from the top rod 21191. When the locking wedge block 21192 and the conical block are disengaged from each other, the locking wedge block 21192 will disengage from the annular groove 2123 with the cooperation of the elastic part until it returns to its original position, thereby releasing the limit of the plug-in rod 211 in the plug-in groove 2121, making it convenient for the staff to replace the steel mesh body 2 with different specifications and increasing the patch efficiency of the circuit board.

[0071] It is worth noting that the steel mesh main body 2 adopts a detachable protective frame 22, and the steel mesh body 23 is installed using the slots 24 in the protective frame 22. During the solder paste printing process, solder paste and other debris may remain on the surface of the steel mesh, requiring regular cleaning. The detachable protective frame 22 makes the disassembly of the steel mesh more convenient and quick, and the steel mesh body 23 can be easily removed from the protective frame 22 for comprehensive and thorough cleaning to avoid the problem of solder paste residue affecting the subsequent solder paste printing effect. In different circuit board patch projects, steel mesh bodies 23 of different thicknesses or opening shapes are required. The detachable protective frame 22 is conducive to the rapid replacement of the steel mesh body 23. Compared with the integral protective frame 22, it improves the flexibility and efficiency of production and can quickly adapt to the production needs of different products.

[0072] The present invention uses the calibration piece 21, which has the following advantages:

[0073] Advantage 1: A conical surface is provided on the upper part of the plug-in slot 2121, which serves as an initial guide. When the plug-in rod 211 approaches the plug-in slot 2121, the conical surface can guide the plug-in rod 211 to roughly align with the center of the plug-in slot 2121, making it easier for the plug-in rod 211 to enter the plug-in hole. In addition, the diameter of the plug-in slot 2121 is larger than the diameter of the plug-in rod 211. There is no need for the staff to deliberately calibrate the position of the steel mesh body 2 on the steel mesh frame 12. It is only necessary to place the plug-in rod 211 in the plug-in seat 212, which simplifies the installation steps of the steel mesh body 2 and increases the installation efficiency of the steel mesh body 2.

[0074] Advantage 2: The guide rod 2113 will slowly move downward under the action of the electromagnetic block 2114. The movable plate 2112 cooperates with the inclined plate 2117 and the inclined surface of the movable rod 2116 to drive the correction plate 2115 connected to the movable rod 2116 to move synchronously. One of the correction plates 2115 will first approach and contact the inner wall of the plug-in slot 2121. The correction plate 2115 will give the guide rod 2113 a reaction force pointing to the center of the plug-in slot 2121. This reaction force will continuously adjust the plug-in rod 2113. 11, so that the plug rod 211 gradually moves toward the center position of the plug slot 2121 until the central axis of the plug rod 211 coincides with the central axis of the plug slot 2121, and the central axes of the four plug rods 211 coincide with the central axes of the plug socket 212 respectively, thereby ensuring that the steel mesh body 2 is in the center position of the steel mesh frame 12, avoiding the inability to accurately align the steel mesh body 2 with the welding position of the circuit board during installation, resulting in the deviation of the solder paste printing position, affecting the subsequent welding quality of electronic components.

[0075] Advantage three: when installing the steel mesh body 2, the guide rod 2113 in each plug-in rod 211 and the top rod 21191 are adsorbed by the electromagnetic block 2114, which can ensure that the force applied to each part is uniform, and avoid the steel mesh body 2 being twisted and deformed by unbalanced external forces, resulting in an uneven surface, which in turn affects the printing quality of the solder paste.

[0076] Advantage four, with the cooperation of the correction plate 2115, the guide rod 2113 will be aligned with the push rod 21191, and then the conical block on the push rod 21191 can accurately enter the opening groove 2118, and the conical block squeezes the inclined surface of the locking wedge 21192, so that it extends outward and engages in the annular groove 2123 (the block 2124 will engage with the groove 21193), making the locking process simpler and faster, and the "engaging structure" formed by the locking wedge 21192 and the annular groove 2123 can play a certain role in preventing misoperation. Even if it is subjected to external vibration or accidental touch, the plug-in rod 211 will not easily fall out of the plug-in groove 2121, because the locking wedge 21192 requires specific conditions (the current direction of the electromagnetic block 2114 changes) to release the engagement, which increases the safety and reliability of the equipment operation and reduces the risk of safety accidents caused by loose connections.

[0077] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A circuit board patch process with a rapid die change structure, characterized in that: include: S1. Material preparation: prepare the corresponding circuit boards, surface mount components, solder paste, steel mesh and other auxiliary materials according to the circuit board design requirements; S2. Solder paste printing: Place the circuit board on the solder paste printer platform, pour an appropriate amount of solder paste on the steel mesh, and use a scraper to evenly scrape the solder paste across the steel mesh at a certain speed and pressure, so that the solder paste passes through the openings of the steel mesh and is printed on the pads of the circuit board; S3, SPI inspection, using high-precision SPI inspection equipment to perform three-dimensional inspection on the printed solder paste to check whether the volume, height and offset parameters of the solder paste meet the requirements; S4, component placement, put the prepared components into the material station of the placement machine, and the placement machine places them on the corresponding position of the circuit board according to the pre-programmed program; S5, AOI inspection: After the components are mounted, AOI inspection equipment is used to inspect the circuit board after mounting through high-resolution cameras and image processing technology; S6, reflow soldering, the circuit board after patching is sent into the reflow soldering furnace for soldering, so that the solder paste melts, and the molten solder forms a good solder connection between the component pins and the circuit board pads. After cooling, the components can be soldered on the circuit board; S7, functional test, perform functional test on the soldered circuit board to verify whether it meets the product design requirements; S8. Cleaning and packaging: Use ultrasonic cleaning or solvent cleaning to remove the flux, oil and dust remaining on the surface of the circuit board after welding. Pack the cleaned and inspected qualified circuit boards and take protective measures against moisture, static electricity and collision. The solder paste printer in S2 comprises a housing (1), a frame (11) is detachably mounted in the space enclosed by the housing (1), and a steel grid (12) is fixedly connected to the inner side of the frame (11); A steel mesh body (2), the steel mesh body (2) being arranged on the surface of the steel mesh frame (12), and a calibration piece (21) for adjusting the position of the steel mesh body (2) being provided on the joint surface between the steel mesh body (2) and the steel mesh frame (12); The calibration member (21) comprises a plug-in rod (211), four of which are arranged in an array along the central circumference of the steel mesh body (2), and the steel mesh frame (12) is fixedly connected to a plug-in seat (212) via a mounting cavity (121) provided therein, and a plug-in groove (2121) is provided on the upper surface of the plug-in seat (212), and the diameter of the plug-in groove (2121) is larger than the diameter of the plug-in rod (211); The plug-in rod (211) is detachably mounted on the lower surface of the guard frame (22); a cavity (2111) is provided inside the plug-in rod (211); a movable plate (2112) is slidably connected in the cavity (2111); the movable plate (2112) is connected to the upper surface of the cavity (2111) via a round wire spring provided on the top thereof; the cavity (2111) is slidably connected to a guide rod (2113) fixed to the lower surface of the movable plate (2112) via a slot provided on the lower surface thereof; and an electromagnetic block (2114) is fixedly connected to the lower surface of the guide rod (2113).

2. The circuit board placement process with a rapid die change structure according to claim 1, characterized in that: The frame (11) is slidably connected to a solder paste feeding assembly (13) for printing solder paste via an electric slide assembly arranged at its upper portion, and the frame (11) is slidably connected to a loading assembly (14) for conveying circuit boards via an electric slide assembly arranged at its lower portion.

3. The circuit board placement process with a rapid die change structure according to claim 1, characterized in that: The steel mesh main body (2) comprises a protective frame (22) and a steel mesh body (23); the protective frame (22) is detachable, and a slot (24) for installing the steel mesh body (23) is provided in the protective frame (22).

4. The circuit board placement process with a rapid die change structure according to claim 1, characterized in that: The upper portion of the plug-in slot (2121) is provided with a conical surface, the bottom end of the plug-in seat (212) is provided with a through hole (2122), the inner wall of the through hole (2122) is provided with an annular groove (2123), and the inner wall of the annular groove (2123) is provided with a clamping block (2124).

5. The circuit board placement process with a rapid die change structure according to claim 1, characterized in that: The plug rod (211) is slidably connected to a correction plate (2115) that fits the inner wall of the plug slot (2121) through a mounting groove provided on its circumferential outer surface; a movable rod (2116) is fixedly connected to the side of the correction plate (2115) away from the inner wall of the plug slot (2121); the movable rod (2116) passes through the circumferential outer surface of the plug rod (211) and extends into the cavity (2111); an inclined surface is provided at one end of the movable rod (2116) away from the correction plate (2115); and an inclined plate (2117) that slides with the inclined surface of the movable rod (2116) is fixedly connected to the bottom end of the movable plate (2112).

6. The circuit board placement process with a rapid die change structure according to claim 4, characterized in that: An opening slot (2118) is provided inside the guide rod (2113), and a locking mechanism (2119) for limiting the position of the guide rod (2113) is provided inside the opening slot (2118); The locking mechanism (2119) includes a push rod (21191), which is fixedly connected in the installation cavity (121). The push rod (21191) is arranged directly below the socket (212). A conical block is provided at the top of the push rod (21191), and a magnetic connection is formed between the upper surface of the push rod (21191) and the electromagnetic block (2114).

7. The circuit board placement process with a rapid die change structure according to claim 6, characterized in that: The opening groove (2118) is slidably connected to a locking wedge (21192) through a sliding hole opened on its inner wall, and the locking wedge (21192) is provided in plurality and distributed in an array along the central circumference of the guide rod (2113). The locking wedge (21192) is connected to the inner wall of the sliding hole through an elastic member provided on its lower surface. The locking wedge (21192) is provided with a groove (21193) that fits with the block (2124) on the side away from the guide rod (2113), and the locking wedge (21192) is provided with a conical surface that fits with the conical block on the side away from the groove (21193).

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