A disassembly fixture and disassembly process for multiple large-size chips

Abstract

This invention belongs to the field of circuit board rework technology, specifically relating to a disassembly fixture and process for multiple large-sized chips. The disassembly fixture includes a support base, a counterweight heat transfer block, and a cover plate. The circuit board is installed and fixed on the support base. After the circuit board is installed, the large-sized chips on the circuit board face upwards. Multiple collection nets and multiple heat insulation baffles are provided on the cover plate, with the position and number of the heat insulation baffles corresponding one-to-one with the collection nets and the faulty large-sized chips. The hot air flowing through the large-sized chips allows them to detach from the circuit board and fall onto the collection nets. This solution creates a hot air channel for the large-sized chips through the heat insulation baffles. Combined with the counterweight heat transfer block, it allows the faulty large-sized chips to fall onto the collection nets, thus achieving the removal of multiple large-sized chips at once. This reduces the number of thermal shocks the circuit board experiences during chip removal and improves rework efficiency.

Description

Technical Field

[0001] This invention belongs to the field of circuit board rework technology, specifically relating to a disassembly fixture and disassembly process for multiple large-size chips. Background Technology

[0002] After production, circuit boards (PCBAs) often need to be tested. Some circuit boards have large-sized chips installed on them (generally chips larger than 50mm*50mm). If such large-sized chips are removed using a hot air gun, the circuit board (PCBA) often needs to be heated for a long time. When the circuit board (PCBA) is heated, it will be subjected to thermal shock. The longer the thermal shock lasts, the lower the safety and stability of the circuit board (PCBA) will be during use.

[0003] Furthermore, since some circuit boards have multiple large-sized chips, removing each chip individually would increase the number of thermal shocks to the circuit board, further compromising its safety and stability after repair. Moreover, removing large chips one by one also results in low repair efficiency, is highly dependent on the experience of the repair personnel, and makes it difficult to achieve standardized, batch repairs.

[0004] Therefore, how to improve the efficiency of circuit board rework, reduce the number of thermal shocks to circuit boards, and achieve standardized rework has become a problem to be solved. Summary of the Invention

[0005] To address the aforementioned problems in existing technologies, this solution provides a disassembly fixture and disassembly process for multiple large-size chips.

[0006] The technical solution adopted in this invention is as follows:

[0007] A disassembly fixture for multiple large-sized chips includes a support base, a counterweight heat transfer block, and a cover plate;

[0008] The support base is box-shaped with an opening at the top and the inner bottom of the support base is used for mounting and fixing the circuit board; the bottom of the support base is provided with a vent hole; after the circuit board is installed, the large-sized chip on the circuit board faces upward.

[0009] The cover plate matches the shape of the opening at the top of the support base; multiple collection nets are provided on the cover plate, and multiple heat insulation frames are fixed on the inner plate surface of the cover plate. The position and number of the heat insulation frames correspond one-to-one with the collection nets, and the position and number of the collection nets correspond one-to-one with the position and number of large-sized chips that have failed on the circuit board.

[0010] When the cover plate is closed onto the opening at the top of the support base, the heat insulation baffle is fastened onto the corresponding large-size chip, the edge of the heat insulation baffle is close to the edge of the large-size chip, and the counterweight heat transfer block is placed inside the heat insulation baffle and bonded to the large-size chip.

[0011] When the disassembly fixture is placed into the heating device, the cover plate is located below the support base. Hot air can enter from the collection net and flow through the collection net, the gap between the counterweight heat transfer block and the heat insulation baffle, the gap between the heat insulation baffle and the large chip, and the holes on the circuit board in sequence, and then be discharged from the exhaust hole; causing the large chip to detach from the circuit board and fall onto the collection net.

[0012] As an alternative or supplement to the above-mentioned disassembly fixture: the cover plate has multiple covers, each cover plate having different positions or different numbers of heat insulation baffles, so that the heat insulation baffles on at least one cover plate correspond one-to-one with the position and number of large-sized chips that have failed on the circuit board.

[0013] As an alternative or supplement to the above-mentioned disassembly fixture: the cover plate is provided with positioning holes at its edge; the opening of the support base is provided with positioning posts, which can be inserted into the positioning holes to achieve alignment between the cover plate and the support base.

[0014] As an alternative or supplement to the above-mentioned disassembly tooling: a buckle is provided on the outer side wall of the support base, the buckle being used to lock the cover plate.

[0015] As an alternative or supplement to the above-mentioned disassembly fixture: edge rails are provided on the outer side walls of the opposite sides of the support base.

[0016] As an alternative or supplement to the above-mentioned disassembly tooling: the support base is provided with a clamp for fixing the circuit board.

[0017] As an alternative or supplement to the above-mentioned disassembly tooling: the electronic components on the circuit board, except for the large-sized chip that has failed, are covered with heat-insulating pads.

[0018] A disassembly process for a large-size chip, using the disassembly fixture described above, includes the following steps:

[0019] S1: Test the large-sized chips on the circuit board and mark the location of the large-sized chips that have failed;

[0020] S2: Install the circuit board into the support base; attach a counterweight heat transfer block to the large chip that has failed; lay heat insulation pads on other electronic components;

[0021] S3: Install the cover plate onto the support base so that the heat insulation baffle covers the counterweight heat transfer block and the large-size chip;

[0022] S4: Place the disassembly fixture into the heating device with the cover plate facing down, so that hot air can enter the disassembly fixture from the collection net.

[0023] S5: After the heating device starts and the set time is reached, remove the disassembly fixture.

[0024] The beneficial effects of this invention are as follows: This solution can form a hot air channel for the large-sized chip through the heat insulation baffle. With the help of the counterweight heat transfer block, the large-sized chip that has failed can fall into the collection net, thereby removing multiple large-sized chips at once. This reduces the number of thermal shocks that the circuit board is subjected to during chip removal and improves the repair efficiency. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this scheme or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0026] Figure 1 This is a diagram showing the usage status of the support base;

[0027] Figure 2 This is a structural diagram of the cover plate.

[0028] In the diagram: 1-positioning post; 2-fastener; 3-circuit board; 4-counterweight heat transfer block; 5-heat insulation sealing frame; 6-large chip; 7-support base; 8-edge track; 9-positioning hole; 10-edge sealing strip; 11-cover plate; 12-avoidance groove; 13-collection net; 14-heat insulation baffle. Detailed Implementation

[0029] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only a part of the embodiments, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in this solution without creative effort are within the protection scope of this solution.

[0030] Example 1

[0031] like Figures 1 to 2 As shown, this embodiment designs a disassembly fixture for multiple large-size chips 6, including components such as a support base 7, a counterweight heat transfer block 4, and a cover plate 11.

[0032] The mounting base 7 is box-shaped with an opening at the top. When the opening is open, the circuit board 3 can be installed inside the mounting base 7. The inner bottom of the mounting base 7 is used for mounting and fixing the circuit board 3. A support post with internal threads can be provided in the inner bottom of the mounting base 7, and screws passing through the circuit board 3 can fix the circuit board 3 to the mounting base 7. After the circuit board 3 is installed, the large chip 6 on the circuit board 3 is generally in an upward position.

[0033] The bottom of the support base 7 is provided with an exhaust hole, which connects the inner and outer sides of the support base 7, so that the hot air entering the support base 7 can be discharged outward through the exhaust hole.

[0034] The cover plate 11 matches the shape of the opening at the top of the support base 7; when the cover plate 11 is closed on the support base 7, it can close the opening. An edge sealing strip 10 is provided on the outer edge of the cover plate 11, which can seal the gap between the cover plate 11 and the support base 7.

[0035] Multiple collection nets 13 are provided on the cover plate 11, and multiple heat insulation frames 14 are fixed on the inner plate surface of the cover plate 11. The position and number of heat insulation frames 14 correspond one-to-one with the collection nets 13, and the position and number of collection nets 13 correspond one-to-one with the position and number of large-sized chips 6 that have failed on the circuit board 3. Multiple cover plates 11 can be prepared in advance, and each cover plate 11 has different positions or different numbers of heat insulation frames 14. When any combination of large-sized chips 6 that have failed on the circuit board 3 is used, a cover plate 11 can be found to correspond to it, so that the heat insulation frames 14 on the cover plate 11 correspond one-to-one with the position and number of large-sized chips 6 that have failed on the circuit board 3.

[0036] When the cover plate 11 is closed onto the opening at the top of the support base 7, the heat insulation frame 14 covers the corresponding large-size chip 6, the edge of the heat insulation frame 14 covers is close to the edge of the large-size chip 6, and the counterweight heat transfer block 4 is placed inside the heat insulation frame 14 covers and is bonded to the large-size chip 6.

[0037] The cover plate 11 has a positioning hole 9 at its edge; the support base 7 has a positioning post 1 at its opening, and the positioning post 1 can be inserted into the positioning hole 9 to achieve the alignment of the cover plate 11 and the support base 7.

[0038] The outer wall of the support base 7 is provided with a buckle 2, which is used to lock the cover plate 11 to prevent the disassembly tooling from falling off.

[0039] The outer side walls on opposite sides of the support base 7 are provided with edge rails 8, which facilitate the positioning and guidance of the support base 7 in the heating device.

[0040] The support base 7 is provided with a clamp for fixing the circuit board 3. The clamp can replace the support column provided in the support base 7 to fix the circuit board 3. The clamp can be an existing clamping fixture, which will not be listed in detail here.

[0041] The electronic components on the circuit board 3, except for the large-sized chip 6 that has failed, are covered with heat insulation pads. The heat insulation pads can reduce the thermal shock to these electronic components, thereby reducing the probability of these electronic components falling off.

[0042] When the disassembly fixture is placed into the heating device, the cover plate 11 is located below the support base 7. Hot air can enter from the collection net 13 and flow sequentially through the collection net 13, the gap between the counterweight heat transfer block 4 and the heat insulation baffle 14, the gap between the heat insulation baffle 14 and the large-size chip 6, the holes on the circuit board 3, and the gap between the circuit board 3 and the bottom of the support base 7, and then be discharged from the exhaust port. During this process, the hot air melts the solder of the large-size chip 6 and the circuit board 3. The weight of the counterweight heat transfer block 4 and the large-size chip 6 itself causes the large-size chip 6 to detach from the circuit board 3 and fall onto the collection net 13.

[0043] Example 2

[0044] This embodiment designs a disassembly process for a large-size chip 6, using the disassembly fixture from Embodiment 1, including the following steps:

[0045] S1: Test the large-size chip 6 on the circuit board 3 and mark the location of the faulty large-size chip 6;

[0046] S2: Install the circuit board 3 into the support base 7; and attach the counterweight heat transfer block 4 to the large-sized chip 6 that has failed; and lay heat insulation pads on other electronic components.

[0047] S3: Install the cover plate 11 onto the support base 7 so that the heat insulation baffle 14 covers the counterweight heat transfer block 4 and the large-size chip 6.

[0048] S4: Place the disassembly fixture with the cover plate 11 facing down into the heating device so that hot air can enter the disassembly fixture from the collection net 13.

[0049] S5: After the heating device has been started for the set time (generally, ensure that the large-sized chip 6 that has malfunctioned is detached from the circuit board 3), remove the disassembly fixture.

[0050] The above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation; it is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom remain within the scope of this technology.

Claims

1. A disassembly fixture for multiple large-size chips, characterized in that: Includes a support base (7), a counterweight heat transfer block (4), and a cover plate (11); The support base (7) is square box shaped, with an opening at the top. The inner bottom of the support base (7) is used for mounting and fixing the circuit board (3). The bottom of the support base (7) is provided with an exhaust hole. After the circuit board (3) is installed, the large-sized chip (6) on the circuit board (3) faces upward. The cover plate (11) matches the shape of the opening at the top of the support base (7); multiple collection nets (13) are provided on the cover plate (11), and multiple heat insulation frames (14) are fixed on the inner plate surface of the cover plate (11). The position and number of the heat insulation frames (14) correspond one-to-one with the collection nets (13), and the position and number of the collection nets (13) correspond one-to-one with the position and number of the large-sized chips (6) that have failed on the circuit board (3); When the cover plate (11) is closed onto the opening at the top of the support base (7), the heat insulation frame (14) is fastened onto the corresponding large-size chip (6), the edge of the heat insulation frame (14) is close to the edge of the large-size chip (6), and the counterweight heat transfer block (4) is placed inside the heat insulation frame (14) and bonded to the large-size chip (6). When the disassembly fixture is placed into the heating device, the cover plate (11) is located below the support base (7), and hot air can enter from the collection net (13) and flow through the collection net (13), the gap between the counterweight heat transfer block (4) and the heat insulation baffle (14), the gap between the heat insulation baffle (14) and the large-size chip (6), the holes on the circuit board (3), and then be discharged from the exhaust hole; causing the large-size chip (6) to detach from the circuit board (3) and fall onto the collection net (13); The cover plate (11) has multiple covers, each cover plate (11) having different positions or different numbers of heat insulation baffles (14) so ​​that the heat insulation baffles (14) on at least one cover plate (11) correspond one-to-one with the position and number of the large-sized chip (6) that has failed on the circuit board (3); The circuit board (3) is covered with heat-insulating pads on all electronic components except for the faulty large-size chip (6).

2. The disassembly fixture for multiple large-size chips according to claim 1, characterized in that: The cover plate (11) has a positioning hole (9) at its edge; the support base (7) has a positioning post (1) at its opening, and the positioning post (1) can be inserted into the positioning hole (9) to achieve the alignment of the cover plate (11) and the support base (7).

3. The disassembly fixture for multiple large-size chips according to claim 2, characterized in that: The outer wall of the support base (7) is provided with a buckle (2), which is used to lock the cover plate (11).

4. The disassembly fixture for multiple large-size chips according to claim 1, characterized in that: Edge rails (8) are provided on the outer walls of opposite sides of the support base (7).

5. The disassembly fixture for multiple large-size chips according to claim 1, characterized in that: The support base (7) is provided with a clamp for fixing the circuit board (3).

6. A disassembly process for a large-size chip, using the disassembly fixture described in any one of claims 1-5, characterized in that: Includes the following steps: S1: Test the large-size chip (6) on the circuit board (3) and mark the location of the large-size chip (6) that failed; S2: Install the circuit board (3) into the support base (7); and attach a counterweight heat transfer block (4) to the large chip (6) that has failed; and lay heat insulation pads on other electronic components; S3: Install the cover plate (11) onto the support base (7) so that the heat insulation baffle (14) covers the counterweight heat transfer block (4) and the large-size chip (6); S4: Place the disassembly fixture with the cover plate (11) facing down into the heating device so that hot air can enter the disassembly fixture from the collection net (13); S5: After the heating device has been started for the set time, remove the disassembly fixture.

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