Cold cutting device for CGA packaging device and using method

Abstract

The invention discloses a cold cutting device for a CGA packaging device and a using method, and belongs to the technical field of cutting. The left end of a cross beam of the device is provided with a movable rod, the right end of the cross beam is provided with a fixed rod, the movable rod can translate along the cross beam, a screw and a spring are arranged between the fixed rod and the movable rod in a penetrating mode, and the screw enables the distance between the movable rod and the fixed rod to be adjustable and determined; the movable rod and the fixed rod are kept close to each other through the tension of the spring, a metal cutting line is erected between the fixed rod and the movable rod, and the other spring is connected with the metal cutting line to keep the tension of the metal line. During use, the screwing length of the screw is adjusted, so that the distance between the fixed rod and the movable rod is adjusted; the fastening screw is rotated to contract the metal cutting wire, so that the metal cutting wire is in a tightened state; placing a metal cutting line in a central area where the device is connected with a printed board welding column; the welding columns are rubbed back and forth, and finally all the welding columns are disconnected, so that the device is dismounted from the printed board. The device is simple, practical, small and flexible.

Description

Technical Field

[0001] This invention belongs to the field of cutting technology and relates to a cold cutting device and its usage method for CGA packaged devices. Background Technology

[0002] Pillared Grid Array (CGA) packaged devices are widely used in aerospace electronic products with high reliability requirements due to their advantages such as vibration resistance, ease of cleaning, and good thermal matching. With the widespread use of these devices, some CGA packages have become faulty. These faulty CGA packages need to be removed after board-level assembly. Rework benches are used for heated removal, which involves secondary remelting of internal and external solder joints. This results in the fault not recurring after disassembly, greatly increasing the difficulty of troubleshooting.

[0003] Domestic patent applications CN202510199984.9 and CN202511098196.7 have published methods for cutting solder posts used in CGA packaged devices. CN202510199984.9 describes cutting the solder posts to different lengths after drawing, while CN202511098196.7 describes automatically detecting and cutting the solder posts after drawing. Both applications involve length cutting during solder post production. However, none of the published patents address the issue of narrow horizontal spacing between CGA devices after board-level assembly due to obstacles above and below. Therefore, there is an urgent need for a cold-cutting removal method and apparatus for CGA packaged devices to quickly remove board-level faulty CGA packaged devices and achieve precise fault location. Summary of the Invention

[0004] This invention provides a method and apparatus for cold cutting and removing CGA packaged devices. The application of this method significantly improves the efficiency of CGA device fault analysis. The use of cold cutting removal fixtures reduces the difficulty of cold cutting and removal, while increasing the efficiency of device removal, reducing the number of heating cycles on the printed circuit board, and improving the long-term reliability of the product.

[0005] A cold cutting device for CGA packaged devices includes a crossbeam at the upper end, a movable rod at the left end of the crossbeam, and a fixed rod at the right end of the crossbeam. The movable rod can move horizontally along the crossbeam. A screw and a spring are respectively inserted between the fixed rod and the movable rod. The screw allows the distance between the movable rod and the fixed rod to be adjusted and determined. The tension of the spring keeps the movable rod and the fixed rod close together. A metal cutting wire is strung between the fixed rod and the movable rod and connected to the metal cutting wire by another spring to maintain the tension of the metal wire.

[0006] Furthermore, the metal wire fastening device includes a pair of fixed pulleys located at the lower ends of the moving rod and the fixed rod, respectively, through which the metal cutting wire passes.

[0007] Furthermore, the crossbeam is provided with a groove, and the end of the moving rod is provided with a protrusion, which slides inside the groove.

[0008] Furthermore, a boss is provided at the upper end of the moving rod, and the upper end face of the boss contacts the lower end face of the crossbeam.

[0009] Furthermore, the fixed rod and the moving rod maintain a 90° angle with the crossbeam.

[0010] Furthermore, the screw passes through the threaded hole of the fixed rod, with the other end abutting against the moving rod.

[0011] Furthermore, one end of the spring is connected to the fixed rod, and the other end is connected to the boss.

[0012] Furthermore, a rotating fastening screw is installed on the fixed rod, with one end of a metal cutting wire wrapped around the rotating fastening screw and the other end connected to the boss via another spring.

[0013] A cold cutting method for a CGA packaged device, using any of the aforementioned apparatus, the cold cutting method comprising the following steps: S1. Measure the width of the CGA device and adjust the screw tightening length according to the width of the CGA device to adjust the distance between the fixed rod and the moving rod; S2. Rotate the fastening screw to retract the metal cutting line, bringing it to a taut state; S3. Place the metal cutting line between the moving rod and the stationary rod in the central area where the device connects to the solder post on the printed circuit board; S4. Use metal cutting wire to rub the solder pillars back and forth until all solder pillars are broken, thus removing the device from the printed circuit board.

[0014] Compared with existing similar technologies, the advantages and beneficial effects of this invention are mainly: (1) The device of the present invention is simple, practical, compact and flexible, and suitable for the disassembly of CGA devices; (2) Using a rework station to heat and disassemble CGA devices may cause secondary remelting of the internal and external solder joints of CGA devices, and some device faults may not be reproduced, making fault analysis more difficult. The cold cutting disassembly method does not involve heating and can achieve accurate positioning of faulty parts.

[0015] (3) Using the method of the present invention, no heating is required. During the disassembly of CGA devices, the number of heating times of the printed circuit board is reduced, the long-term reliability of the printed circuit board and the components on the printed circuit board is improved, and the long-term reliability of the product is ultimately improved. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the present invention; Figure 2 It is a top view of the moving rod; Figure 3 This is a left view of the position of the fixed pulley below the moving rod; Figure 4 This is a front view of the location of the rotating fastening screw.

[0017] The labels in the diagram are: 1-moving rod, 2-spring, 3-screw, 4-spring, 5-fixed pulley, 6-metal wire, 7-rotating fastening screw, 8-crossbeam, 9-fixed rod, 10-bore. Detailed Implementation

[0018] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments. However, this explanation does not limit the scope of protection of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0019] like Figure 1 As shown, a cold cutting removal device for CGA packaged devices is disclosed. The cold cutting removal device includes a removal fixture and a wire fastening device. The upper end of the removal fixture is provided with a crossbeam 8, the left end of the crossbeam is provided with a movable rod 1, and the right end of the crossbeam is provided with a fixed rod 9. A screw 3 and a spring 4 are provided between the fixed rod 9 and the movable rod 1. The left end of the wire fastening device is provided with a spring 2, the lower end of the wire fastening device is provided with a pair of fixed pulleys 5, and the right end of the wire fastening device is provided with a rotating fastening screw 7.

[0020] The upper end of the dismantling fixture is provided with a crossbeam 8, and a groove is provided in the center of the crossbeam, allowing the movable rod 1 to slide inside the groove. Preferably, the sliding of the groove achieves a distance of 29mm between the fixed rod and the movable rod.

[0021] A movable rod 1 is provided at the left end of the crossbeam 8, with a protruding top that slides within a groove in the crossbeam. At the lower end of the crossbeam 8, a large boss 10 is provided on the upper part of the movable rod 1 to prevent the movable rod 1 from rotating during movement. Preferably, the boss 10 has a diameter of 10mm and a height of 5mm. A fixed rod 9 is provided at the right end of the crossbeam 8, and the fixed rod 9 is fixedly connected to the crossbeam 8 at a 90° angle. The upper end of the fixed rod 9 is provided with a threaded hole for adjusting the screw 3. Preferably, the length of the fixed rod 9 is 40mm and the diameter of the threaded hole is 3mm.

[0022] A screw 3 and a spring 4 are provided between the fixed rod 9 and the movable rod 1. The screw 3 is mainly screwed into the threaded hole of the fixed rod and is used to adjust the distance between the fixed rod and the movable rod 9. The spring 4 is used to connect the fixed rod 9 and the movable rod 1, so that the movable rod 1 and the screw 3 are in close contact. Preferably, the screw 3 is 35mm long and the original length of the spring is 10mm.

[0023] A spring 2 is provided at the left end of the metal wire fastening device. The spring 2 is connected to the boss 10 of the moving rod, so that it moves with the moving rod. The spring 2 is connected to the metal wire, so that the metal wire can be tightened after loosening during the cutting process, thereby increasing the tension of the metal wire. Preferably, the original length of the spring 2 is 3mm, and the metal wire is a steel wire. Preferably, the lower end of the metal wire fastening device is provided with a fixed pulley 5, and the fixed rod 9, movable rod 1, and fixed pulley 5 are used to change the direction of the metal wire. Preferably, the diameter of the fixed pulley 5 is 5mm; The right end of the metal wire fastening device is provided with a rotating fastening screw 7, which is fixed on the fixed rod 9. Rotating the fastening screw 7 adjusts the length of the metal wire to achieve a taut state. Preferably, the diameter of the rotating fastening screw 7 is 2mm, and the diameter of the metal wire is 0.1mm. A cold cutting removal method for CGA packaged devices includes the following steps: S1. Measure the width of the CGA device and adjust the screw tightening length according to the width of the CGA device to adjust the distance between the fixed rod and the moving rod; S2. Rotate the fastening screw to retract the metal wire, bringing it to a taut state; S4. Place the metal wire between the moving rod and the stationary rod in the central area where the device connects to the solder post on the printed circuit board; S5. Use metal wires to rub the solder pillars back and forth until all the solder pillars are broken, and the device can be removed from the printed circuit board.

[0024] By adopting the above-mentioned dismantling method, the risk of secondary remelting of internal and external solder joints of faulty CGA devices during the dismantling process of the rework station is eliminated, and the faulty parts are accurately located. At the same time, the number of heating times of the printed circuit board is reduced, the long-term reliability of the printed circuit board and the components on the printed circuit board is improved, and the long-term reliability of the product is ultimately improved.

Claims

1. A cold cutting device for CGA packaged devices, characterized in that, The device has a crossbeam at its upper end, a movable rod at the left end of the crossbeam, and a fixed rod at the right end of the crossbeam. The movable rod can move along the crossbeam. A screw and a spring are respectively inserted between the fixed rod and the movable rod. The screw makes the distance between the movable rod and the fixed rod adjustable and fixed. The tension of the spring keeps the movable rod and the fixed rod close together. A metal cutting wire is strung between the fixed rod and the movable rod and connected to the metal cutting wire by another spring to maintain the tension of the metal wire.

2. The cold cutting apparatus for CGA packaged devices according to claim 1, characterized in that, The metal wire fastening device includes a pair of fixed pulleys located at the lower ends of the moving rod and the fixed rod, respectively, and the metal cutting wire passes through the fixed pulleys.

3. The cold cutting apparatus for CGA packaged devices according to claim 1, characterized in that, The crossbeam is provided with a groove, and the end of the moving rod is provided with a protrusion, which slides inside the groove.

4. The cold cutting apparatus for CGA packaged devices according to claim 1, characterized in that, The upper end of the moving rod is provided with a boss, and the upper end face of the boss is in contact with the lower end face of the crossbeam.

5. The cold cutting apparatus for CGA packaged devices according to claim 1, characterized in that, The fixed rod and the moving rod maintain a 90° angle with the crossbeam.

6. The cold cutting apparatus for CGA packaged devices according to claim 1, characterized in that, The screw passes through the threaded hole of the fixed rod, and the other end abuts against the moving rod.

7. The cold cutting apparatus for CGA packaged devices according to claim 4, characterized in that, One end of the spring is connected to the fixed rod, and the other end is connected to the boss.

8. The cold cutting apparatus for CGA packaged devices according to claim 4, characterized in that, A rotating fastening screw is installed on the fixed rod. One end of the metal cutting wire is wrapped around the rotating fastening screw, and the other end is connected to the boss through another spring.

9. A cold cutting method for a CGA packaged device, characterized in that, Using the apparatus of any one of claims 1 to 8, the cold cutting method comprises the following steps: S1. Measure the width of the CGA device and adjust the screw tightening length according to the width of the CGA device to adjust the distance between the fixed rod and the moving rod; S2. Rotate the fastening screw to retract the metal cutting line, bringing it to a taut state; S3. Place the metal cutting line between the moving rod and the stationary rod in the central area where the device connects to the solder post on the printed circuit board; S4. Use metal cutting wire to rub the solder pillars back and forth until all solder pillars are broken, thus removing the device from the printed circuit board.

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