Self-limiting backflow clamp tool

Abstract

The utility model relates to a kind of with self-limiting reflow fixture tool, the utility model's with self-limiting reflow fixture tool is equipped with self-limiting positioning, visual operation, high-temperature stability, by the synergistic effect of packaging shell, self-limiting fixture bottom plate, self-limiting fixture top plate and needle limiting lifting plate, high-precision alignment (error≤0.05mm) of reflow needle and chip is realized.The whole lifting type needle control is used, and clamping time is shortened from 120 seconds to 30 seconds, and efficiency is improved by 400%.Through the hollow area in the middle of lifting plate, the operator can observe the chip position in real time, avoiding breaking the gold wire, solving the problem of traditional fixture positioning difference, low efficiency, easy to damage chip, suitable for reflow soldering of various precision electronic components.

Description

Technical Field

[0001] This utility model relates to a self-limiting reflow fixture, belonging to the technical field of reflow soldering process equipment for electronic components. Background Technology

[0002] In the reflow soldering process of electronic packaging, the alignment accuracy, clamping efficiency, and structural stability of the reflow pins and the reflow chip directly determine the product yield. Traditional reflow fixtures require assembling the reflow pins one by one. Due to the large number of pins (often dozens), manual handling is required to align the pins with the chip pads. If a pin suddenly falls during the process, it can easily break the gold wires of the chip solder joint, resulting in scrap. A single fixture setup takes up to 120 seconds per cycle, resulting in extremely low production efficiency.

[0003] CN210549227U discloses a semiconductor laser chip welding fixture, including a base. Two brackets are symmetrically fixed on both sides of the upper surface of the base. The brackets have an inverted "T" shape. A fixing frame is arranged between the two brackets. A central pressure block is arranged in the middle of the bottom of the fixing frame, and a side pressure block is arranged on one side of the bottom of the fixing frame. A housing is provided on the upper surface of the base, and a fixing seat is arranged inside the housing. This semiconductor laser chip welding fixture uses side pressure blocks and a central pressure block with a stepped bottom to fix the laser chip during semiconductor laser welding. By fixing the same laser chip with two adjacent pressure blocks, the force of one pressure block acts on two laser chips simultaneously, ensuring uniform force on the laser chips inside the entire laser, effectively improving the flatness of the laser chip welding, and effectively improving the operability of laser spot compression and shaping. The chip welding fixture adjusts the pressure using springs, but it cannot guarantee that all springs will deform in the same way, resulting in differences in the pressure applied to each COS. Secondly, the pressure required by the COS during welding is not easy to measure, as the pressure in this application is the weight of the pressure pin, which is constant. Furthermore, this application requires sequentially fixing the fixing frame to the bracket through the connecting shaft and through the through hole, and then adjusting the screw length to control the pressure, which wastes a lot of time in production. In addition, it also needs to be disassembled sequentially after welding, making the process complex. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this utility model provides a fixture with a self-limiting return flow.

[0005] This utility model's self-limiting reflow fixture combines self-limiting positioning, visual operation, and high-temperature stability. It is used to achieve high-precision alignment and welding of reflow pins and reflow chips, solving the technical pain points of low clamping efficiency and easy chip damage of traditional fixtures. Invention Overview:

[0007] This utility model's reflow fixture with self-limiting positioning combines self-limiting positioning, visual operation, and high-temperature stability. Through the coordinated action of the encapsulation shell, the self-limiting fixture base plate, the self-limiting fixture top plate, and the pressure pin limiting lifting plate, it achieves high-precision alignment (error ≤ 0.05mm) between the reflow pressure pin and the chip. Employing an integrated lifting pressure pin control, the clamping time is reduced from 120 seconds to 30 seconds, increasing efficiency by 400%. Simultaneously, the rigid structure of the threaded connection and clearance fit ensures no deformation at 260℃, with a repeatability accuracy ≤ 0.02mm. The hollowed-out area in the middle of the lifting plate allows operators to observe the chip position in real time, avoiding breakage of gold wires. This solves the problems of poor positioning, low efficiency, and easy chip damage associated with traditional fixtures, making it suitable for reflow soldering of various precision electronic components.

[0008] This utility model is achieved through the following technical solution:

[0009] A self-limiting reflow fixture includes a package shell, a package shell limiting groove on the package shell, and a reflow chip installed in the package shell limiting groove to limit the reflow chip.

[0010] A self-limiting fixture base plate is provided at the upper end of the packaging shell. The self-limiting fixture base plate is provided with a hollow base plate clearance groove that matches the limiting groove of the packaging shell. A base plate limiting protrusion is provided around the base plate clearance groove. A base plate limiting hole is provided between the limiting protrusion and the base plate clearance groove.

[0011] A pressure needle limiting lifting plate is provided inside the limiting protrusion of the self-limiting fixture base plate. The limiting protrusion limits the pressure needle limiting lifting plate. Manual lifting blocks extending outward are provided at both ends of the pressure needle limiting lifting plate. The pressure needle limiting lifting plate is provided with an elongated hole, which is opposite to the limiting hole of the base plate.

[0012] The self-limiting clamp base plate is equipped with a support column, which is threadedly connected to the self-limiting clamp base plate;

[0013] A self-limiting clamp top plate is provided on the support column, which is threadedly connected to the support column.

[0014] The bottom of both ends of the top plate of the self-limiting fixture is provided with downward-extending limiting blocks to limit the movement distance of the manually lifted block;

[0015] The top plate of the self-limiting fixture is provided with a fixture top plate limiting groove, which is opposite to the elongated hole of the limiting lifting plate;

[0016] The reflow pressure pin passes through the limiting groove of the top plate of the fixture, the elongated hole of the limiting lifting plate, and the limiting hole of the bottom plate of the fixture to press the reflow chip.

[0017] According to a preferred embodiment of this utility model, the number of limiting holes in the bottom plate is 50-60.

[0018] According to a preferred embodiment of this utility model, the top end of the bottom plate limiting protrusion is lower than the bottom end of the limiting pressure block, which is used to limit the distance by which the limiting pressure pin and the lifting plate are vertically lifted upward.

[0019] According to a preferred embodiment of this utility model, the height of the bottom plate limiting protrusion is 2-4mm.

[0020] The height of the limiting protrusion of this utility model is higher than the height that can be lifted, so as to prevent the lifting plate from falling out.

[0021] According to a preferred embodiment of the present invention, the pressure needle limiting lifting plate is provided with a hollow lifting plate clearance groove in the middle.

[0022] According to a preferred embodiment of the present invention, the size of the pressure needle limiting lifting plate is consistent with the area enclosed by the limiting protrusion.

[0023] According to a preferred embodiment of the present invention, the manual lifting block and the pressure needle limiting lifting plate are fixedly connected by screws.

[0024] According to a preferred embodiment of this invention, the position of the manual lifting block is opposite to the position of the limiting pressure block. The limiting pressure block prevents the pressure needle limiting lifting plate from rising too high and disengaging from the limiting clamp base plate, thus serving as a limiting force for the upward movement.

[0025] According to a preferred embodiment of this invention, the distance between the manual lifting block and the limiting pressure block is 1-3mm.

[0026] According to a preferred embodiment of this invention, the number of limiting grooves in the top plate is the same as the number of limiting holes in the bottom plate.

[0027] The method for reflow soldering using the above-mentioned self-limiting reflow fixture includes the following steps:

[0028] 1) Pass the return pressure needle through the limiting groove of the top plate of the fixture, the elongated hole of the limiting lifting plate, and the limiting hole of the bottom plate of the fixture;

[0029] 2) Manually lift the manual lifting block to lift the entire set of fixture reflow pressure pins. Lower the manual lifting block to lower the reflow pressure pins onto the reflow chip, press them down, and perform reflow soldering.

[0030] In summary, the self-limiting return fixture of this utility model has the following structure:

[0031] 1. Triple self-limiting structure: The pre-positioning chip is pre-positioned through the limiting groove of the encapsulated shell, the holes and grooves of the self-limiting fixture top plate and the self-limiting fixture bottom plate constrain the radial displacement of the pressure needle, and the elongated hole of the limiting lifting plate on the pressure needle limiting lifting plate provides axial fine adjustment, forming a precise positioning chain of "pre-positioning-radial constraint-axial fine adjustment".

[0032] 2. Visual operation design: A rectangular hollowed-out lifting plate clearance slot is set in the middle of the lifting plate. During the clamping process, the chip position can be directly observed through the clearance slot, and real-time fine adjustment is supported.

[0033] 3. Overall lifting mechanism: The manual lifting block connects to the lifting plate to realize the synchronous lifting of multiple pressure needles, avoiding the inefficiency and risks of traditional single-needle assembly;

[0034] 4. High-temperature stable connection: The support column and the base plate are connected by threads, and the top plate and the support column are fixed by countersunk screws. The limiting pressure block strengthens the structural rigidity and ensures stability in high-temperature environments.

[0035] Technical features and advantages of this utility model:

[0036] 1. Precision Guarantee: The movement path of the reflux pressure needle of this utility model is subject to triple constraints: "fixture top plate limiting groove (radial constraint) - limiting lifting plate elongated hole (axial fine adjustment + radial constraint) - bottom plate limiting hole (final positioning)," which forces the precise alignment of "no radial offset and axial adjustment" and eliminates human operation error.

[0037] 2. High operational efficiency: The manual lifting block + self-limiting design reduces clamping time to 30 seconds per cycle. In traditional solutions, due to the pre-assembly of the pins, all pins descend as a whole during reflow fixture installation. It is impossible to manually observe the reflow chip position in advance and descend slowly, increasing the probability of the reflow chip soldering gold wire. It is necessary to manually assemble the reflow pressure pins one by one to prevent sudden descent from pressing on the reflow chip soldering gold wire. The entire assembly takes 120 seconds per cycle. The current solution uses a pressure pin limiting lifting plate in conjunction with a manual lifting block to lift the reflow pressure pins as a whole and manually control their slow descent. The hollow part in the middle of the pressure pin limiting lifting plate allows observation of whether the COS position is offset or the pressing situation, allowing for appropriate fine-tuning. Production efficiency is increased by 400%, and no professional skills are required, reducing the manual threshold.

[0038] 3. The rigid structure of threaded connection and clearance fit does not deform or loosen at a high temperature of 260℃, and the repeated clamping accuracy deviation is ≤0.02mm. Attached Figure Description

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments;

[0040] Figure 1 This is a schematic diagram of the axial side state of the self-limiting return fixture tooling of this utility model;

[0041] Figure 2 This is a front view schematic diagram of the self-limiting return fixture tooling of this utility model;

[0042] Figure 3 A front view of the top plate of the self-limiting clamp of this utility model;

[0043] Figure 4 A front view schematic diagram of the pressure needle limiting and lifting plate of this utility model;

[0044] Figure 5 A front view schematic diagram of the self-limiting clamp base plate of this utility model;

[0045] In the diagram: 1. Encapsulation shell; 2. Self-limiting fixture base plate; 3. Support column; 4. Manual lifting block a; 5. Manual lifting block b; 6. Limiting pressure block a; 7. Self-limiting fixture top plate; 8. Reflow pressure pin; 9. Reflow chip; 10. Limiting pressure block b; 11. Pressure pin limiting lifting plate; 12. Base plate limiting hole; 13. Limiting protrusion; 14. Limiting lifting plate elongated hole; 15. Lifting plate clearance groove; 16. Top plate limiting groove. Detailed Implementation

[0046] The present utility model patent will be further described below with reference to the embodiments and accompanying drawings, but it is not limited thereto.

[0047] Example 1:

[0048] A self-limiting return fixture, structure as follows Figure 1 , Figure 2 As shown, it includes a package housing 1, a package housing limiting groove is provided on the package housing, and a reflow chip 9 is installed in the package housing limiting groove to limit the reflow chip 9;

[0049] A self-limiting fixture base plate 2 is provided at the upper end of the packaging shell. The self-limiting fixture base plate 2 is clearance-fitted with the packaging shell and constrained by tolerance. The self-limiting fixture base plate 2 is provided with a hollow base plate clearance groove that matches the limiting groove of the packaging shell. A base plate limiting protrusion 13 is provided around the clearance groove. A base plate limiting hole 12 is provided between the limiting protrusion 13 and the clearance groove. The number of base plate limiting holes is 52.

[0050] A pressure needle limiting lifting plate 11 is provided inside the limiting protrusion 13 of the self-limiting fixture base plate 2. The size of the pressure needle limiting lifting plate 11 is consistent with the area enclosed by the limiting protrusion. The limiting protrusion 13 limits the pressure needle limiting lifting plate 11. Manual lifting blocks a4 and b5 extending outward are provided at both ends of the pressure needle limiting lifting plate 11. The manual lifting blocks are fixedly connected to the pressure needle limiting lifting plate 11 by screws.

[0051] The pressure needle limiting lifting plate 11 is provided with a limiting lifting plate elongated hole 14, which is opposite to the bottom plate limiting hole 12. The pressure needle limiting lifting plate 11 is provided with a hollow lifting plate clearance groove in the middle.

[0052] The self-limiting clamp base plate 2 is provided with a support column 3, and the support column 3 is threadedly connected to the self-limiting clamp base plate 2;

[0053] A self-limiting clamp top plate 7 is provided on the support column 3, which is threadedly connected to the support column 3;

[0054] Limiting blocks a6 and b10 extending downward are provided at the bottom of both ends of the top plate 7 of the self-limiting clamp to limit the movement distance of the manually lifted block;

[0055] The top plate of the self-limiting clamp is provided with a clamp top plate limiting groove 16, which is opposite to the elongated hole 14 of the limiting lifting plate.

[0056] The reflow pressure pin passes through the limiting groove of the top plate of the fixture, the elongated hole of the limiting lifting plate, and the limiting hole of the bottom plate of the fixture to press the reflow chip.

[0057] The top of the bottom plate limiting protrusion is lower than the bottom of the limiting pressure block, used to limit the vertical upward lifting distance of the pressure pin and the lifting plate. The height of the bottom plate limiting protrusion is 3mm.

[0058] The position of the manual lifting block is opposite to the position of the limiting pressure block. The limiting pressure block prevents the pressure needle limiting lifting plate from rising too high and dislodging from the limiting fixture base plate, thus serving as a limit to the rise. The distance between the manual lifting block and the limiting pressure block is 2mm, and the number of limiting grooves on the top plate is the same as the number of limiting holes on the bottom plate.

[0059] Example 2:

[0060] The fixture with self-limiting return flow described in Example 1 differs in that:

[0061] The number of bottom plate limiting holes is 55, and the number of plate limiting grooves is the same as the number of bottom plate limiting holes.

[0062] The height of the bottom plate limiting protrusion is 2mm, and the distance between the manual lifting block and the limiting pressure block is 1mm.

[0063] Example 3:

[0064] The fixture with self-limiting return flow described in Example 1 differs in that:

[0065] The number of bottom plate limiting holes is 60, and the number of plate limiting grooves is the same as the number of bottom plate limiting holes.

[0066] The height of the bottom plate limiting protrusion is 4mm, and the distance between the manual lifting block and the limiting pressure block is 3mm.

[0067] Example 4:

[0068] The method for reflow soldering using the self-limiting reflow fixture tooling described in Example 1 includes the following steps:

[0069] 1) Pass the return pressure needle through the limiting groove of the top plate of the fixture, the elongated hole of the limiting lifting plate, and the limiting hole of the bottom plate of the fixture;

[0070] 2) Manually lift the manual lifting block to lift the entire set of fixture reflow pressure pins. Lower the manual lifting block to lower the reflow pressure pins onto the reflow chip, press them down, and perform reflow soldering.

Claims

1. A self-limiting reflow fixture, comprising a package shell, a package shell limiting groove provided on the package shell, and a reflow chip installed in the package shell limiting groove to limit the reflow chip; A self-limiting fixture base plate is provided at the upper end of the packaging shell. The self-limiting fixture base plate is provided with a hollow base plate clearance groove that matches the limiting groove of the packaging shell. A base plate limiting protrusion is provided around the base plate clearance groove. A base plate limiting hole is provided between the limiting protrusion and the base plate clearance groove. A pressure needle limiting lifting plate is provided inside the limiting protrusion of the self-limiting fixture base plate. The limiting protrusion limits the pressure needle limiting lifting plate. Manual lifting blocks extending outward are provided at both ends of the pressure needle limiting lifting plate. The pressure needle limiting lifting plate is provided with an elongated hole, which is opposite to the limiting hole of the base plate. The self-limiting clamp base plate is equipped with a support column, which is threadedly connected to the self-limiting clamp base plate; A self-limiting clamp top plate is provided on the support column, which is threadedly connected to the support column. The bottom of both ends of the top plate of the self-limiting fixture is provided with downward-extending limiting blocks to limit the movement distance of the manually lifted block; The top plate of the self-limiting fixture is provided with a fixture top plate limiting groove, which is opposite to the elongated hole of the limiting lifting plate; The reflow pressure pin passes through the limiting groove of the top plate of the fixture, the elongated hole of the limiting lifting plate, and the limiting hole of the bottom plate of the fixture to press the reflow chip.

2. The fixture with self-limiting return flow according to claim 1, characterized in that, The number of limiting holes on the bottom plate is 50-60.

3. The fixture with self-limiting return flow according to claim 1, characterized in that, The top of the bottom plate limiting protrusion is lower than the bottom of the limiting pressure block, which is used to limit the distance by which the pressure pin and lifting plate are lifted vertically upward.

4. The fixture with self-limiting return flow according to claim 1, characterized in that, The height of the bottom plate limiting protrusion is 2-4mm.

5. The fixture with self-limiting return flow according to claim 1, characterized in that, The pressure needle limiting lifting plate has a hollow lifting plate clearance groove in the middle.

6. The fixture with self-limiting return flow according to claim 1, characterized in that, The size of the pressure needle limiting lifting plate is consistent with the area enclosed by the limiting protrusion.

7. The fixture with self-limiting return flow according to claim 1, characterized in that, The manual lifting block and the pressure needle limit lifting plate are fixedly connected by screws.

8. The fixture with self-limiting return flow according to claim 1, characterized in that, The position of the manual lifting block is opposite to the position of the limit pressure block; the limit pressure block prevents the pressure needle limit lifting plate from rising too high and dislodging from the limit fixture base plate, thus serving as a limit for the rise.

9. The fixture with self-limiting return flow according to claim 1, characterized in that, The distance between the manually lifted block and the limit block is 1-3mm.

10. The fixture with self-limiting return flow according to claim 1, characterized in that, The number of limiting grooves in the top plate is the same as the number of limiting holes in the bottom plate.

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