High-precision positioning jig for SMT (Surface Mount Technology) mounting line

Abstract

The invention relates to the field of integrated circuit manufacturing, in particular to a high-precision positioning jig for an SMT (surface mount technology) mounting line, which comprises a tray for bearing a circuit board, the positioning mechanism is arranged on the tray and comprises a pressing assembly and a wedge-shaped assembly, and the wedge-shaped assembly is used for triggering the pressing assembly to press and position the circuit board before solder paste printing; according to the invention, the tray is used for bearing the circuit board, and the wedge-shaped assembly in the positioning mechanism is used for triggering the pressing assembly to carry out horizontal pressing positioning on the circuit board, so that the assembly is ensured to be flush with the upper surface of the tray in a non-working state, and the requirement of solder paste printing and component surface mounting for no projection interference is met; the steel mesh attaching gap or visual identification interference is avoided; and a limiting assembly is triggered by a shifting assembly in the reinforcing mechanism to tightly press the circuit board in the vertical direction, so that the fixed dimension is supplemented, and multidirectional stress generated by thermal expansion of the circuit board at high temperature in reflow soldering is effectively counteracted.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of integrated circuit manufacturing, and particularly relates to a high-precision positioning jig of SMT mounting line. BACKGROUND

[0002] In the production process of SMT mounting line in the field of integrated circuit manufacturing, the positioning of the circuit board is a key link to guarantee the quality of tin paste printing, component mounting and reflow soldering. The current mainstream positioning method is to use a printing, mounting and reflow soldering integrated positioning jig. Such a jig usually includes a tray for carrying the circuit board, and the tray is provided with elastic clamping components. When in use, the elastic clamping components are actuated to reserve a space for placing the circuit board. After the circuit board is placed in the accommodating groove of the tray, the elastic components are loosened, and the elastic force is used to press the circuit board against the edge on the opposite side of the accommodating groove, so as to realize the positioning of the circuit board. The integrated design reduces the frequency of changing the jig, saves the production cost, and improves the production efficiency of the SMT mounting line. However, there are still some defects. The original intention of the current design of only side elastic clamping is to adapt to the demand of tin paste printing process and component mounting process without protrusion interference. If a vertical pressing positioning structure is used, a protrusion will be formed during printing, which will prevent the steel mesh from completely adhering to the surface of the circuit board, causing tin paste missing printing or interference with the visual system during component mounting. However, this design only retains the horizontal side clamping in order to consider the printing adhesion and component mounting, which results in single fixed dimension. In the high-temperature environment of reflow soldering, the multidirectional stress generated by the thermal expansion of the circuit board cannot be completely offset by single horizontal fixation, which may cause uncontrollable displacement of the circuit board, thereby becoming a potential risk for high-precision soldering quality. SUMMARY

[0003] In view of the above or the problem in the prior art that the single fixed dimension is caused by only retaining the horizontal side clamping in order to consider the printing adhesion and component mounting, the present application is proposed.

[0004] Therefore, the purpose of the present application is to provide a high-precision positioning jig of SMT mounting line.

[0005] To solve the above technical problems, the present application provides the following technical solutions. A high-precision positioning jig of SMT mounting line, comprising, a tray for carrying a circuit board; a positioning mechanism arranged on the tray, the positioning mechanism comprising a pressing assembly and a wedge-shaped assembly, the wedge-shaped assembly being used to trigger the pressing assembly to press and position the circuit board before tin paste printing; The reinforcing mechanism arranged on the tray comprises a limiting assembly and a poking assembly, the poking assembly is used for poking the limiting assembly to compress the circuit board in the vertical direction before reflow soldering, so that the thermal expansion displacement of the circuit board during soldering is avoided, and the tray does not need to be replaced; The control mechanism arranged on the tray comprises a traction assembly and a ratchet assembly, the traction assembly is used for traction control positioning mechanism and reinforcing mechanism.

[0006] As a preferred scheme of the high-precision positioning jig of the SMT mounting line, the tray is fixedly installed with a protective cover, a spring telescopic rod one is fixedly installed on the inner wall of the protective cover, a moving frame is fixedly installed on the outer side of the telescopic section of the spring telescopic rod one, the moving frame is slidingly sleeved on the outer side of the fixed section of the spring telescopic rod one, and the wedge-shaped assembly and the poking assembly are connected with the moving frame.

[0007] As a preferred scheme of the high-precision positioning jig of the SMT mounting line, the positioning mechanism, the reinforcing mechanism and the spring telescopic rod one are provided with two groups of each other symmetrically along the width direction of the protective cover, and the compression assembly, the wedge-shaped assembly, the limiting assembly and the poking assembly are provided with two groups of each other symmetrically along the length direction of the protective cover.

[0008] As a preferred scheme of the high-precision positioning jig of the SMT mounting line, the compression assembly comprises a fixed plate fixedly installed on the side of the tray close to the protective cover, a contact plate is fixedly installed on the fixed plate through a return spring one, a plurality of accommodating grooves are formed in the tray, the contact plate is in L shape, and the horizontal section of the contact plate is slidingly penetrated through the tray and communicated with the corresponding accommodating groove.

[0009] As a preferred scheme of the high-precision positioning jig of the SMT mounting line, the wedge-shaped assembly comprises a wedge-shaped rod fixedly installed on the outer side of the moving frame, and a wedge-shaped block matched with the wedge-shaped rod is fixedly installed on the vertical section of the contact plate.

[0010] As a preferred scheme of the high-precision positioning jig of the SMT mounting line, the limiting assembly comprises a sliding rail vertically and slidingly installed on the tray, and a limiting plate is slidingly installed in the sliding rail through a return spring two.

[0011] As a preferred scheme of the high-precision positioning jig of the SMT mounting line, the poking assembly comprises a fixed seat fixedly installed on the outer side of the moving frame and a control groove formed on the side of the fixed seat away from the moving frame, a poking rod is fixedly installed on the side of the limiting plate close to the sliding rail, and the poking rod is slidingly penetrated through the sliding groove on the sliding rail and slidingly connected with the control groove.

[0012] As a preferred scheme of the high-precision positioning jig of the SMT mounting line, the control groove is composed of a lower horizontal section, a lower inclined section, an upper inclined section and an upper horizontal section.

[0013] As a preferred scheme of the high-precision positioning jig of the SMT mounting line, the traction assembly comprises a rotating shaft rotatably arranged on the side of the tray close to the protective cover and two winding wheels fixedly arranged on the outer side of the rotating shaft, the outer sides of the two winding wheels are both provided with traction ropes, the directions of winding are the same, the telescopic end of the spring telescopic rod one is fixedly provided with a traction plate, and the traction rope end is fixedly connected with the corresponding traction plate.

[0014] As a preferred scheme of the high-precision positioning jig of the SMT mounting line, the traction assembly comprises a rotating shaft rotatably arranged on the side of the tray close to the protective cover and two winding wheels fixedly arranged on the outer side of the rotating shaft, the outer sides of the two winding wheels are both provided with traction ropes, the directions of winding are the same, the telescopic end of the spring telescopic rod one is fixedly provided with a traction plate, and the traction rope end is fixedly connected with the corresponding traction plate.

[0015] The high-precision positioning jig of the SMT mounting line has the following beneficial effects: In the present application, the circuit board is carried by the tray, the circuit board is horizontally positioned by the wedge-shaped component triggering the pressing component in the positioning mechanism, the components are flush with the upper surface of the tray in the non-working state, the demand for no protruding interference in the tin paste printing and component mounting is met, and the steel mesh fitting gap or visual recognition interference is avoided; the circuit board is pressed from the vertical direction by the actuating component triggering the limiting component in the strengthening mechanism, the fixed dimension is supplemented, the multidirectional stress generated by the thermal expansion of the circuit board under the high temperature of the reflow soldering is effectively offset, and the displacement problem caused by the existing side elastic clamping is solved; the positioning and the action of the strengthening mechanism are accurately controlled by the traction component and the ratchet component, and the tray does not need to be replaced to adapt to multiple processes; the cost and efficiency advantages of the integrated jig are retained, the defects of single fixed dimension and high-temperature displacement are completely solved, and the positioning precision of the SMT mounting line in the whole process and the reflow soldering quality are guaranteed. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the present application.

[0018] Figure 2The internal part of the protective cover of the present application is shown in the perspective view.

[0019] Figure 3 The partial perspective view of the tray and the protective cover of the present application is shown in the sectional view.

[0020] Figure 4 The internal part of the protective cover of the present application is shown in the perspective view. Figure 3 The local enlarged view of part A of the present application is shown in the perspective view. Figure 5 The internal part of the protective cover of the present application is shown in the perspective view.

[0021] Figure 6 The internal part of the protective cover of the present application is shown in the perspective view.

[0022] Figure 7 The internal part of the protective cover of the present application is shown in the perspective view.

[0023] Figure 8 The internal part of the protective cover of the present application is shown in the perspective view.

[0024] Figure 9 The internal part of the protective cover of the present application is shown in the perspective view.

[0025] Figure 10 The internal part of the protective cover of the present application is shown in the perspective view.

[0026] In the figure: 1, tray; 2, positioning mechanism; 21, compression assembly; 211, fixed plate; 212, reset spring one; 213, contact plate; 22, wedge assembly; 221, wedge block; 222, wedge rod; 3, reinforcing mechanism; 31, limiting assembly; 311, sliding rail; 312, reset spring two; 313, limiting plate; 32, actuating assembly; 321, actuating rod; 322, control groove; 3221, lower horizontal section; 3222, lower inclined section; 3223, upper inclined section; 3224, upper horizontal section; 323, fixed seat; 4, control mechanism; 41, traction assembly; 411, rotating shaft; 412, winding wheel; 413, traction rope; 414, traction plate; 42, ratchet assembly; 421, ratchet; 422, pawl; 423, rotating ring; 424, spring telescopic rod two; 425, knob; 5, spring telescopic rod one; 6, moving frame; 7, protective cover. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0028] Referring to Figure 1 , Figure 2 ,Figure 3 and Figure 10 The embodiment provides a high-precision positioning jig of an SMT mounting line, which can realize the advantages of cost and efficiency of an integrated jig, and completely solve the problems of single fixed dimension and high-temperature displacement, and comprises a tray 1 for bearing a circuit board; a protective cover 7 is fixedly installed on the tray 1, a spring telescopic rod one 5 is fixedly installed on the inner wall of the protective cover 7, a moving frame 6 is fixedly installed on the outer side of the telescopic section of the spring telescopic rod one 5, and the moving frame 6 is slidingly sleeved on the outer side of the fixed section of the spring telescopic rod one 5; a positioning mechanism 2 is arranged between the tray 1 and the protective cover 7, the positioning mechanism 2 comprises a pressing assembly 21 and a wedge-shaped assembly 22, and the wedge-shaped assembly 22 is used for triggering the pressing assembly 21 to position the circuit board before tin paste printing. A reinforcing mechanism 3 is arranged between the tray 1 and the protective cover 7, the reinforcing mechanism 3 comprises a limiting assembly 31 and a poking assembly 32, the poking assembly 32 is used for poking the limiting assembly 31 to press the circuit board in the vertical direction before reflow soldering, so that thermal expansion displacement of the circuit board during soldering is avoided, and the tray 1 does not need to be replaced; the wedge-shaped assembly 22 and the poking assembly 32 are connected with the moving frame 6; a control mechanism 4 is arranged between the tray 1 and the spring telescopic rod one 5, the control mechanism 4 comprises a traction assembly 41 and a ratchet assembly 42, and the traction assembly 41 is used for traction control of the positioning mechanism 2 and the reinforcing mechanism 3.

[0029] With reference to Figure 1 , Figure 2 and Figure 3 , the positioning mechanism 2, the reinforcing mechanism 3 and the spring telescopic rod one 5 are all provided with two groups of each other which are symmetrical along the width direction of the protective cover 7, and the pressing assembly 21, the wedge-shaped assembly 22, the limiting assembly 31 and the poking assembly 32 are all provided with two groups of each other which are symmetrical along the length direction of the protective cover 7.

[0030] It should be noted that four accommodating grooves are formed in the tray 1, and the above-mentioned positioning mechanism 2, reinforcing mechanism 3 and the like are all flush with the height of the upper surface of the tray 1 in the tin paste printing and component mounting sections of the circuit board, so that the process operation is not affected, the steel mesh can be completely attached to the surface of the circuit board during printing, no attachment gap caused by the protrusion blockage, tin paste printing deviation or abnormal amount is prevented, and the problem that the part exceeding the height of the tray 1 blocks the visual system from recognizing the Mark point of the circuit board is avoided during mounting, and the collision between the suction nozzle and the protruding part during mounting of the component is prevented, so that the mounting precision and safety are ensured.

[0031] With reference to Figure 2 , Figure 3 , Figure 4 and Figure 5The traction assembly 41 comprises a rotating shaft 411 rotatably installed on the tray 1 near the protective cover 7 and two winding wheels 412 fixedly installed outside the rotating shaft 411, the two winding wheels 412 are provided with traction ropes 413 outside, and the winding directions are the same, the traction plates 414 are fixedly installed at the telescopic ends of the spring telescopic rod 5, and the traction ropes 413 are fixedly connected with the corresponding traction plates 414.

[0032] It should be noted that the two winding wheels 412 are provided in the same direction, so that the two traction ropes 413 can be synchronously contracted and relaxed when the rotating shaft 411 rotates, the rotating shaft 411 is the spring telescopic rod three, and the telescopic section and the fixed end of the rotating shaft 411 are connected through a key groove.

[0033] Referring to Figure 3 , Figure 4 , Figure 5 and Figure 6 , the ratchet assembly 42 comprises a ratchet 421 fixedly sleeved outside the rotating shaft 411, the side of the tray 1 near the protective cover 7 is rotatably provided with a pawl 422 matched with the ratchet 421 through a torsion spring, the side of the ratchet 421 away from the protective cover 7 is rotatably provided with a rotating ring 423, the rotating ring 423 and the tray 1 are fixedly installed with a spring telescopic rod 424, and the end of the rotating shaft 411 away from the protective cover 7 is fixedly installed with a rotating knob 425.

[0034] It should be noted that the pawl 422 is connected with the tray 1 through the torsion spring, the torsion spring can continuously provide the pawl 422 with a force in the direction of the ratchet 421, so as to ensure that the pawl 422 is always engaged with the ratchet 421, and the rotating shaft 411 is unidirectionally locked, that is, the rotating shaft 411 can only rotate in the direction in which the traction rope 413 is contracted, so as to avoid reverse rotation of the rotating shaft 411 due to external interference when the positioning mechanism 2 or the reinforcing mechanism 3 works, and cause the traction rope 413 to be loose. The cooperation of the rotating ring 423 and the spring telescopic rod 424 provides a basis for unlocking, at the same time, the elastic force of the spring telescopic rod 424 can assist the ratchet 421 to reset, so as to ensure that the ratchet 421 and the pawl 422 are accurately engaged next time; the rotating knob 425 is fixed at the end of the rotating shaft 411, so as to facilitate manual or mechanical rotation operation, the rotating shaft 411 is controlled to rotate by rotating the rotating knob 425, the contraction amount of the traction rope 413 can be adjusted, and the accurate action of the positioning mechanism 2 and the reinforcing mechanism 3 can be realized.

[0035] In specific use, before tin paste printing, four circuit boards are placed in the corresponding accommodating grooves, then the knob 425 is rotated to drive the rotating shaft 411 to rotate synchronously, the two winding wheels 412 on the outside of the rotating shaft 411 rotate to synchronously wind the traction ropes 413 on the outside, the traction ropes 413 are wound to exert an axial tension on the traction plate 414, the traction plate 414 drives the extension section of the spring telescopic rod 1 to slide towards the rotating shaft 411, thereby driving the moving frame 6 to move synchronously, and the moving frame 6 slides along the fixed end outer surface in the moving process.

[0036] In the process of rotating the rotating shaft 411 to drive the moving frame 6 to move, the pawl 422 continuously obtains the force in the direction of the ratchet wheel 421 by the torsion spring, so that the pawl 422 is always precisely engaged with the tooth groove of the ratchet wheel 421, only allowing the rotating shaft 411 to rotate in the direction of the contraction of the traction rope 413, limiting the reverse rotation of the rotating shaft 411, preventing the moving frame 6 from deviating due to the loosening of the traction rope 413, and ensuring that the moving frame 6 can stably remain at the target position after traction, thereby providing a fixed reference for the work of the positioning mechanism 2 and the reinforcing mechanism 3; and the rotating ring 423 on one side of the ratchet wheel 421 cooperates with the spring telescopic rod 2 424.

[0037] When the moving frame 6 needs to return to the initial position, the knob 425 is pressed downward, at this time, the rotating ring 423 moves downward to pull the extension section of the spring telescopic rod 2 424 and drive the ratchet wheel 421 to move slightly in the axial direction, so that the tooth groove of the ratchet wheel 421 is disengaged from the engagement with the pawl 422, and the reverse limitation on the rotating shaft 411 is removed; then the spring telescopic rod 1 5 is reset, the rotating shaft 411 reversely rotates to drive the winding wheel 412 to release the traction rope 413, the traction plate 414 and the moving frame 6 return to the initial position, at this time, the teeth of the ratchet wheel 421 are aligned with the pawl 422; then, the knob 425 is released, the spring telescopic rod 2 424 drives the rotating ring 423 and the ratchet wheel 421 to reset, the pawl 422 is engaged with the tooth groove of the ratchet wheel 421 again, and the control mechanism 4 returns to the standby state, ready for the next traction operation.

[0038] Referring to Figure 5 , Figure 6 , Figure 8 and Figure 9 , the pressing assembly 21 comprises a fixed plate 211 fixedly installed on the tray 1 near the protective cover 7, a resisting plate 213 is fixedly installed on the fixed plate 211 through a reset spring 1 212, the resisting plate 213 is in an L shape, and the horizontal section of the resisting plate 213 slidably penetrates the tray 1 and communicates with the corresponding accommodating groove.

[0039] Referring to Figure 6 and Figure 8The wedge-shaped assembly 22 comprises a wedge-shaped rod 222 fixedly installed outside the moving frame 6, and a wedge-shaped block 221 fixedly installed on the vertical section of the abutting plate 213 and matched with the wedge-shaped rod 222.

[0040] It should be noted that the L-shaped structure of the abutting plate 213 has the dual functions of vertical transmission and horizontal abutting and pressing. The vertical section is used to connect with the wedge-shaped block 221 and receive the acting force of the wedge-shaped assembly 22, and the horizontal section penetrates through the tray 1 and is matched with the accommodating groove. In the non-working state, the horizontal section can be completely withdrawn into the accommodating groove and flush with the inner wall surface of the accommodating groove, so as to facilitate the placement of the circuit board. In the working state, the wedge-shaped rod 222 moves with the moving frame 6, the wedge-shaped surface thereof and the inclined surface of the wedge-shaped block 221 are pressed against each other, the linear movement of the moving frame 6 is converted into the transverse movement of the vertical section of the abutting plate 213, and then the horizontal section of the abutting plate 213 is extended out of the accommodating groove to realize the horizontal abutting and pressing positioning from the side edge of the circuit board. The reset spring one 212 is always in the compressed state during the abutting and pressing positioning, and when the wedge-shaped rod 222 is separated from the wedge-shaped block 221, the reset spring one 212 can pull the abutting plate 213 to quickly reset, so that the horizontal section is withdrawn into the accommodating groove, thereby leaving space for the taking and placing of the circuit board or the process switching.

[0041] In specific use, in the process of pulling the moving frame 6 by the traction rope 413, the wedge-shaped rod 222 is driven to move linearly with the moving frame 6, the wedge-shaped surface of the wedge-shaped rod 222 gradually contacts and exerts pressing force on the inclined surface of the wedge-shaped block 221, thereby converting the linear movement of the moving frame 6 into the transverse movement of the vertical section of the abutting plate 213, and pushing the abutting plate 213 to translate as a whole to the circuit board in the accommodating groove and gradually compress the reset spring one 212. With the continuous movement of the moving frame 6, the horizontal section of the abutting plate 213 is gradually extended out of the accommodating groove and pushes the circuit board to be close to the side wall opposite to the accommodating groove. When the wedge-shaped surface of the wedge-shaped rod 222 is separated from the inclined surface of the wedge-shaped block 221, the abutting plate 213 is tightly attached to the side edge of the circuit board, thereby forming stable abutting and pressing positioning from the horizontal direction, limiting the lateral deviation of the circuit board on the tray 1, providing a reliable position reference for the accurate attachment of the steel mesh to the circuit board and the uniform printing of the tin paste, and providing a reliable basis for the pasting of components after printing.

[0042] Referring to Figure 3 , Figure 5 , Figure 6 , Figure 7 and Figure 10 , the limiting assembly 31 comprises a sliding rail 311 vertically and slidingly installed on the tray 1, and a limiting plate 313 slidingly installed in the sliding rail 311 by a reset spring two 312.

[0043] Referring to Figure 5 , Figure 6 and Figure 7The dialing assembly 32 comprises a fixed seat 323 fixedly installed outside the moving frame 6 and a control groove 322 opened on the side of the fixed seat 323 away from the moving frame 6, and the limiting plate 313 is fixedly installed with a dialing rod 321 close to the side of the slide rail 311, and the dialing rod 321 is slidably connected with the control groove 322 by sliding through the slide groove on the slide rail 311, and the control groove 322 is composed of a lower horizontal section 3221, a lower inclined section 3222, an upper inclined section 3223 and an upper horizontal section 3224.

[0044] It should be noted that the four-section design of the control groove 322 corresponds to the complete action process of the dialing rod 321 driving the limiting plate 313: the lower horizontal section 3221 is the initial standby position, at this time the dialing rod 321 is static and does not affect the positioning of the moving frame 6 driving the abutting plate 213 on the circuit board, the limiting plate 313 is flush with the upper surface of the circuit board and flush with the inner wall surface of the accommodating groove, which does not affect the tin printing, component mounting and other previous processes; the lower inclined section 3222 can guide the dialing rod 321 to slide smoothly along the inclined surface, drive the limiting plate 313 to lift until the lower surface of the limiting plate 313 is flush with the upper surface of the circuit board; the inclined surface design of the upper inclined section 3223 is perpendicular to the lower inclined section 3222, so that the dialing rod 321 can be dialled to drive the limiting plate 313 to slide along the slide rail 311 to completely fit the surface of the circuit board, and the circuit board is pressed and limited, realizing the vertical direction of the pressing; the upper horizontal section 3224 is used to lock the position of the dialing rod 321, so that the limiting plate 313 remains in the pressed state, avoiding loosening of the limiting plate 313 due to vibration or thermal expansion and contraction during reflow soldering.

[0045] In specific use, the reinforcing mechanism 3 is in the lower horizontal section 3221 of the control groove 322 during the previous tin printing and component mounting process, at this time the limiting plate 313 is flush with the upper surface of the tray 1 and does not interfere with the steel mesh fitting, visual identification or component mounting; when the positioning mechanism 2 completes positioning, the dialing rod 321 also moves synchronously with the moving frame 6 to the end of the initial section of the control groove 322, that is, it will enter the lower inclined section 3222. Before entering the reflow soldering process, while keeping the positioning mechanism 2 continuously positioning the circuit board, continue to rotate the knob 425 to drive the traction rope 413 to continuously pull the moving frame 6 to move synchronously with the fixed seat 323 fixedly installed with the moving frame 6, and when the control groove 322 moves with the fixed seat 323, the lower inclined section 3222 gradually contacts and presses the dialing rod 321, driving the dialing rod 321 to gradually rise upwards, thereby driving the limiting plate 313 and the slide rail 311 to synchronously lift upwards, until the dialing rod 321 slides into the upper inclined section 3223, the limiting plate 313 completes the lifting action, at this time the lower surface of the limiting plate 313 is flush with the upper surface of the circuit board, preparing for subsequent pressing of the circuit board.

[0046] With the mobile frame 6 continuing to move, the upper inclined section 3223 of the control groove 322 extrudes the push rod 321, drives the push rod 321 to move away from the control groove 322, and thus pushes the limiting plate 313 to move along the slide rail 311 towards the circuit board and compresses the reset spring 312, so that the limiting plate 313 gradually approaches the circuit board. When the push rod 321 slides to the upper horizontal section 3224, the limiting plate 313 closely adheres to the upper surface of the circuit board, and forms a stable pressing force on the circuit board from the vertical direction, thereby effectively limiting the thermal expansion displacement of the circuit board due to high temperature in the reflow soldering process. In the entire soldering process, the push rod 321 is always locked at the upper horizontal section 3224, and the limiting plate 313 is ensured to be in a pressed state.

[0047] After the reflow soldering is completed, the control mechanism 4 drives the mobile frame 6 to reset reversely. With the mobile frame 6 resetting, the wedge-shaped rod 222 moves with the mobile frame 6 and gradually separates from the wedge-shaped block 221. When the wedge-shaped rod 222 separates from the wedge-shaped block 221, the extrusion force of the wedge-shaped rod 222 on the wedge-shaped block 221 disappears, the reset spring 212 releases the stored elastic potential energy, and drives the abutting plate 213 to translate and reset away from the circuit board. When the mobile frame 6 completely returns to the initial position, the wedge-shaped rod 222 completes the reset.

[0048] At the same time when the mobile frame 6 resets, the push rod 321 slides along the upper inclined section 3223 and the lower inclined section 3222 of the control groove 322 in turn to the lower horizontal section 3221, the reset spring 312 completely releases the elastic potential energy, and pulls the limiting plate 313 to reset along the slide rail 311 to the initial position flush with the tray 1. Then, the circuit board after the tin paste printing, component mounting and reflow soldering can be taken out, and a new circuit board can be placed in the accommodating groove, without replacing the tray 1 to enter the next operation cycle.

[0049] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A high-precision positioning fixture for an SMT assembly line, characterized in that: Include, The tray (1) for carrying the circuit board; The positioning mechanism (2) provided on the tray (1), the positioning mechanism (2) includes compression assembly (21) and wedge assembly (22), the wedge assembly (22) is used for triggering the compression assembly (21) to press the positioning of the circuit board before tin printing; The reinforcing mechanism (3) provided on the tray (1), the reinforcing mechanism (3) includes limiting assembly (31) and dialing assembly (32), the dialing assembly (32) is used for dialing limiting assembly (31) from the vertical direction before reflow soldering to compress the circuit board, to avoid the thermal expansion displacement of the circuit board when welding, and without replacing the tray (1); The control mechanism (4) provided on the tray (1), the control mechanism (4) includes traction assembly (41) and ratchet assembly (42), the traction assembly (41) is used for traction control positioning mechanism (2) and reinforcing mechanism (3).

2. The high-precision positioning jig of the SMT mounting line according to claim 1, characterized in that: The tray (1) is fixedly installed with the protective cover (7), the inner wall of the protective cover (7) is fixedly installed with the spring telescopic rod one (5), the telescopic section outer side of the spring telescopic rod one (5) is fixedly installed with the moving frame (6), and the moving frame (6) is slidably connected with the fixed section outer side of the spring telescopic rod one (5), the wedge assembly (22) and the dialing assembly (32) are connected with the moving frame (6).

3. The high-precision positioning jig of the SMT mounting line according to claim 2, characterized in that: The positioning mechanism (2), the reinforcing mechanism (3) and the spring telescopic rod one (5) are provided with two groups of each other along the width direction of the protective cover (7), the compression assembly (21), the wedge assembly (22), the limiting assembly (31) and the dialing assembly (32) are provided with two groups of each other along the length direction of the protective cover (7).

4. The high-precision positioning jig of the SMT mounting line according to claim 3, characterized in that: The compression assembly (21) includes a fixed plate (211) fixedly installed on the tray (1), a contact plate (213) is fixedly installed on the fixed plate (211) through a reset spring one (212), a plurality of accommodating grooves are formed in the tray (1), the contact plate (213) is L-shaped, and the horizontal section of the contact plate (213) is slidably penetrated through the tray (1) and is communicated with the corresponding accommodating groove.

5. The high-precision positioning jig of the SMT mounting line according to claim 4, characterized in that: The wedge assembly (22) includes a wedge-shaped rod (222) fixedly installed on the outer side of the moving frame (6), and a wedge-shaped block (221) matched with the wedge-shaped rod (222) is fixedly installed on the vertical section of the contact plate (213).

6. The high-precision positioning jig of the SMT mounting line according to claim 5, characterized in that: The limiting assembly (31) includes a slide rail (311) slidably installed on the tray (1), and a limiting plate (313) is slidably installed in the slide rail (311) through a reset spring two (312).

7. The high-precision positioning jig of the SMT mounting line according to claim 6, characterized in that: The dialing assembly (32) includes a fixed seat (323) fixedly installed on the outer side of the moving frame (6) and a control groove (322) formed in the fixed seat (323), the limiting plate (313) is fixedly installed with a dialing rod (321), and the dialing rod (321) is slidably penetrated through the sliding groove on the slide rail (311) and is slidably connected with the control groove (322).

8. The high-precision positioning jig of the SMT mounting line according to claim 7, characterized in that: The control groove (322) is composed of a lower horizontal section (3221), a lower inclined section (3222), an upper inclined section (3223) and an upper horizontal section (3224).

9. The high-precision positioning jig of the SMT mounting line according to claim 8, characterized in that: The traction assembly (41) comprises a rotating shaft (411) rotatably installed on the tray (1) and two winding wheels (412) fixedly installed outside the rotating shaft (411), the outside of each of the two winding wheels (412) is provided with a traction rope (413), the telescopic end of the spring telescopic rod one (5) is fixedly installed with a traction plate (414), and the end of the traction rope (413) is fixedly connected with the corresponding traction plate (414).

10. The high-precision positioning jig of the SMT mounting line according to claim 9, characterized in that: The ratchet wheel assembly (42) comprises a ratchet wheel (421) fixedly sleeved outside the rotating shaft (411), a pawl (422) matched with the ratchet wheel (421) is rotatably installed on the tray (1) through a torsion spring, a rotating ring (423) is rotatably installed on the ratchet wheel (421), a spring telescopic rod two (424) is fixedly installed between the rotating ring (423) and the tray (1), and a rotary knob (425) is fixedly installed on the rotating shaft (411).

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