Surface treatment device for bonding wire continuous casting bar
By laser remelting and polishing the continuous cast rod, the surface defects of continuous cast rods are solved, the surface quality and production efficiency are improved, and the line breakage rate and cost are reduced.
Patent Information
- Application Number
- CN202422016495.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2034-08-20
AI Technical Summary
In the prior art, the surface of continuous cast rods is prone to tiny grooves or scratches, and the embedding of graphite particles leads to defects such as interruption, peeling, and burrs during the wire drawing process, resulting in low production efficiency and yield and high cost.
The clamping mechanism is used to combine the laser remelting surface treatment unit and the polishing unit to laser remelting and polishing the continuous cast rod to remove graphite particles and improve surface quality.
The surface quality of bonded wire continuous cast rods is improved, the line break rate is reduced, the production efficiency is improved and the cost is reduced.
Smart Images
Figure CN223114891U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of electronic packaging, and specifically, to a surface treatment device for a continuous casting rod of bonding wire. Background Art
[0002] With the development of electronic packaging towards miniaturization, multi-function and low cost, the packaging industry has put forward higher requirements for packaging forms and packaging materials. As an internal lead for packaging, bonding wire is one of the essential basic materials in the manufacturing process of integrated circuits and semiconductor discrete devices. With the development of integrated circuits and semiconductor devices towards multi-lead packaging, high integration and miniaturization, bonding wires with finer wire diameters and better electrical properties are required for narrow-pitch and long-distance bonding. During the packaging process, the quality of the bonding wire directly affects the bonding quality, thus having a great impact on the reliability and stability of the device. There should be no scratches, pits, scratches, cracks, protrusions and other defects that reduce the service life of the device on the surface of the bonding wire exceeding 5% of the bonding wire diameter.
[0003] In the process of preparing high-quality bonding gold wire, obtaining a continuous casting rod blank with a smooth surface and dense structure is the key, which will directly affect the processing performance of ultra-fine drawing and the performance of ultra-fine wire.
[0004] Specifically, the role of the high-purity graphite mold is to continuously inject the molten metal into its inner cavity and force it to cool through a water-cooled copper sleeve, export the heat of the molten metal, gradually solidify it into a rod blank, and continuously pull out the rod blank with a liquid phase in the core from the lower opening of the mold, creating conditions for its complete solidification in the subsequent secondary cooling area.
[0005] Among them, graphite is the hexagonal crystal form of carbon and has a special layered structure. The binding force between its crystal planes is very weak and it is easy to slide relative to each other. During the continuous casting production process, the friction and wear generated by the dummy bar, billet drawing and vibration are extremely likely to cause the soft graphite in the inner cavity of the mold to fall off in the form of granular or flaky particles. Micro-grooves or scratches are likely to appear on the surface of the continuous casting rod blank, and graphite particles will also be embedded in them.
[0006] As a result, during the subsequent wire drawing process, defects such as intermittent or local peeling, burrs, and scars will occur, causing wire breakage during the wire drawing process, and both the production efficiency and the finished product rate are relatively low.
[0007] In order to solve the above existing problems, people have been seeking an ideal technical solution. Summary of the Utility Model
[0008] The object of the present utility model is to address the deficiencies of the prior art, and thus provide a surface treatment device for bonding wire continuous casting billets, which can solve the problems that tiny grooves or scratches are likely to occur on the surface of continuous casting billets, and graphite particles will also be embedded therein, resulting in defects such as intermittent or local peeling, burrs, and scarring during the subsequent wire drawing process, causing wire breakage during wire drawing, and both the production efficiency and the finished product rate are relatively low. Ultimately, the surface treatment device can remove graphite from the bonding wire continuous casting billets, improve the surface quality, reduce the wire breakage rate, increase the production efficiency, and reduce the production cost.
[0009] To achieve the above object, the technical solution adopted by the present utility model is: a surface treatment device for bonding wire continuous casting billets, comprising a clamping mechanism, a laser remelting surface treatment unit, and a polishing unit;
[0010] The clamping mechanism is used for clamping and fixing the bonding wire continuous casting billet;
[0011] The laser remelting surface treatment unit is used for performing laser remelting treatment on the surface of the bonding wire continuous casting billet;
[0012] The polishing unit is used for polishing the surface of the bonding wire continuous casting billet after laser remelting treatment.
[0013] Based on the above, the clamping mechanism is a rotary clamping mechanism, which is used for clamping the bonding wire continuous casting billet and driving the bonding wire continuous casting billet to perform rotary motion.
[0014] Based on the above, the clamping mechanism is a static clamping mechanism, which is used for clamping the bonding wire continuous casting billet and keeping it stationary.
[0015] Based on the above, both the laser remelting surface treatment unit and the polishing unit are fixed in the direction relative to the bonding wire continuous casting billet, and move axially along the bonding wire continuous casting billet to perform laser remelting treatment and surface polishing treatment on the surface of the bonding wire continuous casting billet.
[0016] Based on the above, both the laser remelting surface treatment unit and the polishing unit perform laser remelting treatment and polishing treatment on the surface of the bonding wire continuous casting billet in a circumferentially distributed manner or a rotary motion manner, in cooperation with a horizontal moving mechanism.
[0017] Based on the above, the clamping mechanism further includes a horizontal moving mechanism, which is used for driving the bonding wire continuous casting billet to perform horizontal reciprocating movement, and the laser remelting surface treatment unit and the polishing unit are fixed in position to perform laser remelting treatment and surface polishing treatment on the surface of the bonding wire continuous casting billet.
[0018] Based on the above, the laser remelting surface treatment unit includes a box body, a laser head, a laser emission device, a protective gas unit, and a horizontal moving mechanism. The box body is installed on the horizontal moving mechanism. The box body is a closed box body, and an inlet and an outlet for passing through the bonded wire continuous casting rod are provided on the box body along the moving direction;
[0019] The laser head is arranged inside the box body and moves with the box body. The laser emission device is connected to the laser head and is used to scan the surface of the bonded wire continuous casting rod to remelt the surface;
[0020] The protective gas unit is used to fill the box body with protective gas to make the inside of the box body slightly positive pressure.
[0021] Based on the above, the polishing unit is a polishing wheel, which is installed on the inlet side and / or the outlet side of the box body and is used to polish the surface of the bonded wire continuous casting rod.
[0022] Based on the above, the clamping mechanism includes a clamping fixture and a rotary mechanism, which are used to clamp one end of the bonded wire continuous casting rod and drive the bonded wire continuous casting rod to perform a rotary motion; the clamping fixture is a chuck or a jaw or a manipulator, and the rotary mechanism includes a support seat, a rotary wheel arranged on the support seat, and a rotary motor for driving the rotary wheel to rotate.
[0023] Based on the above, in the laser remelting surface treatment unit, the laser power is 4000 - 5000W, the scanning speed is 5.0 - 10.0mm / s, the spot size is 2.0 - 4.0mm, and the overlapping rate is 30 - 40%.
[0024] The present utility model has substantial features and progress compared with the prior art. Specifically, the present utility model has the following advantages:
[0025] 1. Under the condition of slightly positive pressure of high-purity protective gas, the laser remelting method fuses the groove and scratch defects of the bonded wire continuous casting billet, and floats and removes the graphite particles embedded in the groove, improving the surface quality of the bonded wire continuous casting billet, reducing the wire breakage rate during the drawing process of the bonded wire, overall increasing the production efficiency of the bonded wire by 60 - 90%, and reducing the production cost by 10 - 20%.
[0026] 2. The laser remelting and polishing of the bonded wire billet are realized simultaneously online, which can very finely adjust the polishing effect, and can conveniently and quickly perform uniform and dense polishing treatment on the bonded wire billet, thereby greatly improving the efficiency of the polishing work in the production of the bonded wire billet and reducing the production cost. Description of the Drawings
[0027] Figure 1 It is a schematic structural diagram of the surface treatment device for the bonded wire continuous casting rod in the present utility model.
[0028] Figure 2It is a comparison of the surface morphologies of the existing bonding wire continuous casting billet and the bonding wire continuous casting billet of this solution.
[0029] Figure 3 It is a comparison of the performance of the bonding wire prepared based on the bonding wire continuous casting rod of this case and the commercially available bonding wire.
[0030] In the figure: 1. Rotary clamping mechanism; 2. Laser remelting surface treatment unit; 3. Polishing wheel; 4. Bonding wire continuous casting rod; 11. Clamping fixture; 12. Rotary mechanism; 21. Box body; 22. Laser head; 23. Laser emission device; 24. Protection gas unit; 25. Horizontal moving mechanism; 26. Inlet; 27. Outlet. Specific embodiments
[0031] Next, through specific embodiments, the technical solutions of the present invention will be further described in detail.
[0032] Embodiment 1
[0033] As Figure 1 shown, a surface treatment device for a bonding wire continuous casting rod includes a clamping mechanism, a laser remelting surface treatment unit, and a polishing unit.
[0034] In this embodiment, the clamping mechanism is a rotary clamping mechanism 1, which is used to clamp the bonding wire continuous casting rod and drive the bonding wire continuous casting rod 4 to rotate. Specifically, it includes a clamping fixture 11 and a rotary mechanism 12, which are used to clamp one end of the bonding wire continuous casting rod and drive the bonding wire continuous casting rod to rotate; the clamping fixture 11 is a chuck or a jaw or a manipulator, and the rotary mechanism 12 includes a support seat, a rotary wheel arranged on the support seat, and a rotary motor for driving the rotary wheel to rotate. Figure 1 Only the clamping fixture 11 and the support seat are disclosed in
[0035] the others, and the other driving structures are not disclosed because they are conventional, so as to make the figure expression clear and not messy.
[0036] The laser remelting surface treatment unit is used to perform laser remelting treatment on the surface of the bonding wire continuous casting rod; in this embodiment, both the laser remelting surface treatment unit and the polishing unit are fixed relative to the direction of the bonding wire continuous casting rod and move along the axial direction of the bonding wire continuous casting rod to perform laser remelting treatment and surface polishing treatment on the surface of the bonding wire continuous casting rod.
[0037] The laser head 22 is disposed within the box body 21 and moves along with the box body. The laser emission device 23 is connected to the laser head 22 and is used to scan the surface of the bonding wire continuous casting bar 4 to remelt the surface.
[0038] The protective gas unit 24 is used to fill the box body 21 with a protective gas to make the inside of the box body 21 slightly positively pressured. In this embodiment, argon is selected as the protective gas. In other embodiments, other types of protective gases can also be selected.
[0039] In this embodiment, in the laser remelting surface treatment unit, the laser power is 4000 - 5000W, the scanning speed is 5.0 - 10.0 mm / s, the spot size is 2.0 - 4.0 mm, and the overlap rate is 30 - 40%.
[0040] The polishing unit is used to polish the surface of the bonding wire continuous casting bar 4 after laser remelting treatment. In the embodiment, the polishing unit is a polishing wheel 3, which is installed on the inlet side and / or the outlet side of the box body 21 and is used to polish the surface of the bonding wire continuous casting bar 4. As Figure 1 shown, the polishing wheel 3 is installed on the inlet side for easy processing.
[0041] Principle of operation description:
[0042] After passing the bonding wire continuous casting bar blank through the inlet and outlet of the box body 21, one end is clamped on the clamping fixture 11 and the other end is suspended. Then, the valve of the protective gas unit is opened to fill the box body 21 with the protective gas and reach a slightly positive pressure. The slightly positive pressure is an air pressure value greater than the standard atmospheric pressure by 200 - 400 Pa.
[0043] Then, the rotary motor is started to drive the clamping fixture to rotate clockwise, driving the bonding wire continuous casting bar blank to rotate. The polishing unit is also started synchronously and can continuously polish the bonding wire continuous casting bar blank.
[0044] The horizontal displacement mechanism 25 is started. In this embodiment, a guide rail type translation workbench is used, and the laser emission device is also started simultaneously.
[0045] As the horizontal displacement mechanism 25 translates towards the suspended end of the bonding wire continuous casting bar blank, the laser head scans the surface of the bonding wire continuous casting bar blank. At the same time, the polishing wheel polishes the scanned part subsequently.
[0046] Laser action principle: In an atmosphere of slightly positive pressure high-purity argon, the laser remelts the surface layer metal of the bonding wire continuous casting bar blank. The surface grooves or scratches are fused. The graphite particles embedded in the grooves have a small density and do not interact with the liquid bonding wire metal. Under the action of surface tension, they float on the surface of the bonding wire continuous casting bar blank and are removed by the polishing wheel when passing through it.
[0047] After the scanning and polishing of the free end are completed, turn off the laser generating device, the horizontal moving mechanism, and the clamping mechanism, remove the bonding wire continuous casting billet, re-clamp it after turning it around, and then scan and polish the other half of the bonding wire continuous casting billet.
[0048] After all operations are completed, remove the bonding wire continuous casting billet, which is the processed bonding wire continuous casting billet.
[0049] Figure 2 The following shows the comparison of the surface morphologies of the existing bonding wire continuous casting billet (a in the figure) and the proposed solution (b in the figure). There are grooves, scratches, and graphite particle inlays on the surface of the bonding wire continuous casting billet in a, while the surface of the bonding wire continuous casting billet processed by the proposed solution in b is smooth, without scratches, grooves, and graphite particle inlay defects.
[0050] Figure 3 The following shows the performance comparison of the prepared bonding wires. a in the figure is a 20μm copper bonding wire made from the bonding wire continuous casting billet of the proposed solution, and b in the figure is a commercially available 20μm copper bonding wire.
[0051] As can be seen from the figure, the surface of the copper bonding wire prepared by the proposed solution is flat, smooth, uniform, and without obvious defects. In contrast, the commercially available copper bonding wire has slight unevenness, scratches, and even peeling defects, which will seriously affect the performance of the copper bonding wire.
[0052] In addition, during the wire bonding process, the working conditions of the bonding wire are very complex. Especially for the bonding wire on a high-speed automatic wire bonder, it is required to have higher breaking force and elongation. For the bonding wire, its breaking force and elongation play a key role in the quality of wire bonding. A bonding wire with high breaking force and elongation is more conducive to wire bonding. Using a YG001 B single-fiber electronic tensile tester, the breaking force and elongation of the 20μm copper bonding wire prepared by the proposed solution and the commercially available 20μm copper bonding wire are measured respectively. Taking the average value of 10 specimens, the breaking force of the bonding wire prepared by the proposed solution is 6.5 cN, while that of the commercially available copper bonding wire is 5.7 cN; the elongation of the bonding wire prepared by the proposed solution is 10.8%, while that of the commercially available copper bonding wire is 9.6%. The breaking force and elongation of the copper bonding wire of the proposed solution are higher than those of the commercially available copper bonding wire.
[0053] Furthermore, according to the metal conduction theory, the reason why metals have resistance is that the electron waves are scattered. However, the scattering of electron waves often occurs where the integrity of the crystal lattice is damaged. According to this principle, Matthiessen's Rule expresses the resistivity (ρ) of metals as: ρ = ρ r + ρ t , ρ r is the resistivity related to impurities and lattice defects (point defects, line defects, and surface defects), and ρ tis the temperature-dependent resistivity. Taking the average value of 10 specimens, the resistivity of the bonding wire prepared by this solution is 0.01715 Ω·mm 2 / m, while the resistivity of the commercially available copper bonding wire is 0.01716 Ω·mm 2 / m. The resistivity of the bonding wire prepared by this solution is significantly lower than that of the commercially available copper bonding wire.
[0054] Example 2
[0055] The main difference between this example and Example 1 is that: the clamping mechanism is a static clamping mechanism, which is used to clamp the bonding wire continuous casting bar and keep it stationary.
[0056] In this solution, the laser remelting surface treatment unit and the polishing unit are both distributed in a surrounding manner or in a rotary motion manner, and cooperate with the horizontal moving mechanism to perform laser remelting treatment and polishing treatment on the surface of the bonding wire continuous casting bar.
[0057] Example 3
[0058] The main difference between this example and Example 1 is that:
[0059] While the clamping mechanism is a rotary clamping mechanism, the laser remelting surface treatment unit and the polishing unit are both distributed in a surrounding manner or in a rotary motion manner, and cooperate with the horizontal moving mechanism to perform laser remelting treatment and polishing treatment on the surface of the bonding wire continuous casting bar.
[0060] Both move relative to each other in a rotary manner, which can improve the efficiency.
[0061] Example 3
[0062] The difference between this example and Example 2 is that: the clamping mechanism further includes a horizontal moving mechanism, which is used to drive the bonding wire continuous casting bar to perform horizontal reciprocating movement, and the laser remelting surface treatment unit and the polishing unit are fixed in position to perform laser remelting treatment and surface polishing treatment on the surface of the bonding wire continuous casting bar.
[0063] That is, the clamping mechanism moves, and the laser remelting surface treatment unit and the polishing unit are fixed in position, which can improve the working stability of the laser remelting surface treatment unit and the polishing unit.
[0064] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: still can modify the specific implementation manners of the present invention or perform equivalent replacements on some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.
Claims
1. A surface treatment device for a bonding wire continuous casting bar, characterized in that: It includes a clamping mechanism, a laser remelting surface treatment unit, and a polishing unit; The clamping mechanism is used to clamp and fix the bonded wire continuous casting bar; The laser remelting surface treatment unit is used to perform laser remelting treatment on the surface of the bonded wire continuous casting bar; The polishing unit is used to polish the surface of the bonded wire continuous casting bar after laser remelting treatment.
2. The surface treatment device for the bonded wire continuous casting rod according to claim 1, characterized in that: The clamping mechanism is a rotary clamping mechanism, which is used to clamp the bonded wire continuous casting bar and drive the bonded wire continuous casting bar to perform rotary motion.
3. The surface treatment device for the bonded wire continuous casting bar according to claim 1, characterized in that: The clamping mechanism is a static clamping mechanism, which is used to clamp the bonded wire continuous casting bar and keep it stationary.
4. The surface treatment device for the bonding wire continuous casting rod according to claim 2, wherein: Both the laser remelting surface treatment unit and the polishing unit are fixed relative to the direction of the bonded wire continuous casting bar, and move along the axial direction of the bonded wire continuous casting bar to perform laser remelting treatment and surface polishing treatment on the surface of the bonded wire continuous casting bar.
5. The surface treatment device for the bonded wire continuous casting rod according to claim 2 or 3, characterized in that: Both the laser remelting surface treatment unit and the polishing unit perform laser remelting treatment and polishing treatment on the surface of the bonded wire continuous casting bar in a circumferential distribution manner or a rotary motion manner, in cooperation with a horizontal moving mechanism.
6. The surface treatment device for the bonded wire continuous casting rod according to claim 2, wherein: The clamping mechanism further includes a horizontal moving mechanism, which is used to drive the bonded wire continuous casting bar to perform horizontal reciprocating movement, and the laser remelting surface treatment unit and the polishing unit are fixed in position to perform laser remelting treatment and surface polishing treatment on the surface of the bonded wire continuous casting bar.
7. The surface treatment device for the bonded wire continuous casting bar according to claim 2 or 4, characterized in that: The laser remelting surface treatment unit includes a box body, a laser head, a laser emission device, a protective gas unit, and a horizontal moving mechanism. The box body is installed on the horizontal moving mechanism. The box body is a closed box body, and an inlet and an outlet for passing through the bonded wire continuous casting bar are provided on the box body along the moving direction; The laser head is arranged in the box body and moves with the box body. The laser emission device is connected to the laser head and is used to scan the surface of the bonded wire continuous casting bar to remelt the surface; The protective gas unit is used to fill the box body with protective gas to make the inside of the box body slightly positively pressurized.
8. The surface treatment device for the bonded wire continuous casting bar according to claim 7, characterized in that: The polishing unit is a polishing wheel, which is installed on the inlet side and / or the outlet side of the box body and is used to polish the surface of the bonded wire continuous casting bar.
9. The surface treatment device for the bonded wire continuous casting bar according to claim 2 or 8, characterized in that: The clamping mechanism includes a clamping fixture and a rotary mechanism, which are used to clamp one end of the bonded wire continuous casting bar and drive the bonded wire continuous casting bar to perform rotary motion; the clamping fixture is a chuck or a jaw or a manipulator, and the rotary mechanism includes a support seat, a rotary wheel arranged on the support seat, and a rotary motor for driving the rotary wheel to rotate.
10. The surface treatment device for the bonded wire continuous casting rod according to claim 1 or 2 or 3 or 4 or 6 or 8, characterized in that: In the laser remelting surface treatment unit, the laser power is 4000 - 5000W, the scanning speed is 5.0 - 10.0mm / s, the spot size is 2.0 - 4.0mm, and the overlap rate is 30 - 40%.