A cobalt-based metal dicing blade and a method of manufacturing the same

Abstract

The application discloses a cobalt-based metal scribing blade and a preparation method thereof, and relates to the technical field of scribing blades. The scribing blade comprises the following components in mass fraction: 2-5 parts of diamond, 50-60 parts of cobalt powder, 20-30 parts of copper-tin 8020 powder, 6-10 parts of tungsten carbide and 10-15 parts of adhesive. The diamond is titanium-plated diamond or diamond shaping material. The application effectively improves the sharpness of the scribing blade and the cutting quality, greatly improves the hardness and wear resistance of the scribing blade, greatly improves the uniformity of the titanium-plated diamond wrapping by the metal powder, improves the wrapping effect of the cobalt-based matrix formed by the metal powder on the diamond, greatly improves the holding force of the cobalt-based matrix on the titanium-plated diamond, greatly prolongs the service life of the scribing blade, and improves the cutting quality.

Description

Technical Field

[0001] This invention relates to the field of dicing blade technology, and more specifically, to a cobalt-based metal dicing blade and its preparation method. Background Technology

[0002] In the back-end processes of semiconductor packaging, dicing blades are typically used to cut and separate the packaging material (usually a composite of easily cut resin and difficult-to-cut copper). For this purpose, dicing blades made of sintered iron and copper are commonly used in the market. However, due to the poor oxidation resistance and low strength of copper and iron, these dicing blades generally have low hardness, as well as low sharpness and wear resistance, resulting in generally poor cutting quality and limited service life.

[0003] Existing technologies for metal sintering blades that can be used to cut semiconductor packaging materials, such as patent application CN113201675A metal adhesive dicing blade and its preparation method, can improve the rigidity and hardness of the dicing blade, extend its service life, and improve the cutting quality to a certain extent through the synergistic effect of metal powders such as copper-tin alloy powder and cobalt powder in the raw materials and diamond.

[0004] However, existing technologies often suffer from the problem of uneven distribution of diamonds in the metal powder of the raw materials. This results in a generally weak holding force of the metal matrix formed by the metal powder on the diamonds, which limits the improvement of the hardness, service life, and cutting quality of the dicing blade. At the same time, most existing technologies still have problems with wear resistance and cutting sharpness, which further affects the service life and cutting quality of the dicing blade.

[0005] Therefore, a new technical solution is needed to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to provide a cobalt-based metal dicing blade and its preparation method, in order to solve the technical problems mentioned in the background art, such as the general uniformity of the metal powder in the raw materials for diamond encapsulation, resulting in a general holding force of the metal matrix formed by the metal powder for diamond, which limits the improvement of the hardness, service life and cutting quality of the dicing blade, and the general wear resistance and sharpness of the existing dicing blade, which further affects the service life and cutting quality of the dicing blade.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A cobalt-based metal dicing blade comprises the following components in parts by weight: 2-5 parts of D20-D30 diamond, 50-60 parts of cobalt powder with a particle size of 1-3 μm, 20-30 parts of copper-tin 8020 powder with a particle size of 2-5 μm, 6-10 parts of tungsten carbide with a particle size of 6-10 μm, and 10-15 parts of binder. The diamond is titanium-plated diamond or diamond shaping material, and the copper-tin 8020 powder is copper-tin alloy powder or elemental copper-tin mixed powder (8:2 copper-tin).

[0008] The preparation method of the above-mentioned cobalt-based metal dicing blade includes the following steps: S1. After sieving the cobalt powder and copper-tin 8020 powder in the formula multiple times and mixing them evenly, add the tungsten carbide and diamond in the formula and stir evenly to obtain a metal powder mixture. S2. Dilute the binder of the specified amount with alcohol and stir well. Then mix it with the metal powder mixture. After it is completely wetted, add alcohol and send it into the three-dimensional mixer to mix evenly. S3. After removing the material from the three-dimensional mixer and drying it, the material is granulated by sieving multiple times. S4. Weigh the granulated material according to the specifications of the cold pressing mold, put it into the cold pressing mold, and then demold it to obtain the dicing blade semi-finished product. S5. After the semi-finished dicing blade is sent into the sintering furnace for high-temperature hot pressing and sintering, it is cooled, demolded, and finished to obtain the finished dicing blade. The specific operation process of high-temperature hot pressing and sintering is as follows: First, the blade is strung on a graphite sintering mandrel and placed in a graphite sintering mold cavity; then, the sintering mold cavity is placed in the sintering furnace, the furnace door is closed and sealed, and then a vacuum is drawn. After the pressure drops to 0.1 MPa, the sintering program is started; next, when the temperature reaches 350℃, it is held for 30 minutes and carbon removal is performed; finally, the temperature is continued to rise, and when the temperature reaches 650℃, a pressure of not less than 12T is applied, and the temperature is continued to rise to 700℃ and held for 30 minutes.

[0009] Furthermore, the amount of alcohol used is 20 to 30 parts; in step S1, it is passed through a 300-mesh sieve at least 3 times; in step S2, the mixing time of the three-dimensional mixer is not less than 1 hour; in step S3, it is passed through a 200-mesh sieve at least 3 times; in step S4, the cold pressing pressure is not less than 500kN and the cold pressing time is not less than 3 seconds.

[0010] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, titanium-plated diamond is selected as the diamond material. In addition to introducing copper-tin 8020 powder, tungsten carbide and cobalt powder are also introduced. This allows the titanium-plated diamond, cobalt powder, copper-tin 8020 powder, tungsten carbide, and binder to work together to effectively improve the sharpness of the dicing blade and enhance cutting quality, while also significantly increasing its hardness and wear resistance. Specifically, the introduction of copper-tin 8020 powder along with tungsten carbide and cobalt powder not only reduces the interfacial tension between the metal powder and diamond, improving their compatibility, but also enhances the alloying degree between the metal powder and the titanium-plated diamond through the addition of titanium powder. This greatly improves the uniformity of the metal powder's coating on the titanium-plated diamond, enhancing the coating effect of the cobalt-based matrix formed by the metal powder on the diamond. This significantly increases the holding force of the cobalt-based matrix on the titanium-plated diamond, greatly extending the service life of the dicing blade and improving cutting quality.

[0011] 2. In this invention, by adding cobalt powder and tungsten carbide and scientifically and rationally designing their ratio, the combination of tungsten carbide and cobalt powder with a hexagonal lattice structure results in a dicing blade that not only has high sharpness and high wear resistance, but also excellent toughness and ductility, and can achieve high strength. Ultimately, this significantly improves the cutting quality and service life of the dicing blade.

[0012] 3. In this invention, the multiple sieving processes of cobalt powder and copper-tin 8020 powder ensure the dispersion effect of the metal powder before mixing, further improving the uniformity of the metal powder coating on the diamond, enhancing the holding force of the cobalt matrix on the diamond, thereby further enhancing the hardness, wear resistance, and sharpness of the dicing blade, extending its service life, and improving the cutting quality. Furthermore, the multiple sieving processes of the material, which has been uniformly mixed by a three-dimensional mixer and dried, further ensure that each diamond is surrounded by cobalt powder and copper-tin powder, thus further guaranteeing the hardness, wear resistance, and sharpness of the dicing blade, ensuring its service life and cutting quality. Detailed Implementation

[0013] The following examples are used to further illustrate the content of the present invention and do not limit the application of the present invention.

[0014] The raw materials used in this invention are all commercially available products. Example 1

[0015] Preparation of cobalt-based metal dicing blades: S1. Weigh out 2 parts of titanium-plated diamond of D20-D30, 50 parts of cobalt powder of 1-3μm, 20 parts of 8020 copper-tin alloy powder of 2-5μm, 6 parts of tungsten carbide of 6-10μm, 10 parts of 1700 adhesive and 20 parts of alcohol. S2. Pass the cobalt powder and 8020 copper-tin alloy powder through a 300-mesh sieve (you can stir while sieving with a spoon), and sieve them three times to ensure that the metal powder is completely dispersed. Then, mix the cobalt powder and 8020 copper-tin alloy powder together and stir with a spoon. Then add tungsten carbide and titanium-plated diamond and stir manually until uniform (visually check that the color does not separate into layers) to obtain a metal powder mixture. S3. Place 1700 binder in a beaker, add alcohol (at least 2 / 3 of the formula amount of alcohol) to dilute and stir well. Pour the above metal powder mixture into the beaker and stir again. After the material is completely wetted (add the remaining amount of alcohol here), put it into the three-dimensional mixer for mixing. Maintain the time for one hour. S4. First, take out the material from the three-dimensional mixer and dry it with a hot air blower to ensure that the alcohol can evaporate completely. Then, pass the dried material through a 200-mesh fine sieve three times. At this point, the granulation of the particles is basically completed, and each diamond is surrounded by cobalt powder and copper-tin powder. S5. Take out the cold pressing mold (the specifications and models of the cold pressing mold can be selected as needed, such as 58*0.15*40, etc.), and weigh the granulated material using an electronic scale (weigh according to the specifications of the cold pressing mold). First, place the cold pressing mold in the automatic scraping table groove, then put the weighed material into the cold pressing mold using a feeding funnel. Then, start the automatic scraping table to scrape the material. After the machine stops and the material is scraped evenly, cover the mold with the pressure head, take out the cold pressing mold containing the material, and place it under a 5t press. Use a pressure of 500KN for cold pressing for 3 seconds. S6. First, demold the cold-pressed blade (at this time, the surface of the blade is smooth and without cracks, and has a little strength). Then, use a plate to lift the blade and set it aside (you can scrape several blades). S7. After stringing the blades on the graphite sintering mandrel (with graphite spacers separating different blades), place them together in the graphite sintering mold cavity. S8. First, place the sintering mold cavity into the sintering furnace, then close the furnace door and seal it. Then, evacuate the vacuum. After the pressure drops to 0.1 MPa, start the sintering program. When the temperature reaches 350℃, hold it for 30 minutes and perform carbon removal to remove the residue of the 1700 binder added during the granulation process. Then, continue to raise the temperature. When the temperature reaches 650℃, the upper and lower pressure heads begin to apply a pressure of 12T. Continue to raise the temperature to 700℃ and hold it for 30 minutes. S9. After cooling, demold and remove the blade; S10. Perform finishing on the blade (including two processes: double grinding and inner and outer circular grinding) to obtain the finished cobalt-based metal dicing blade. Example 2

[0016] Preparation of cobalt-based metal dicing blades: The preparation method of this embodiment is the same as that of Example 1, except that: 1) diamond shaping material is used; 2) the formulation amounts of each raw material are different, namely 3 parts diamond shaping material, 52 parts cobalt powder, 23 parts 8020 copper-tin alloy powder, 7 parts tungsten carbide, 11.5 parts 1700 binder and 22 parts alcohol. Example 3

[0017] Preparation of cobalt-based metal dicing blades: The preparation method of this embodiment is the same as that of Example 1, except that the formulation amounts of each raw material are different, namely 5 parts of titanium-plated diamond, 60 parts of cobalt powder, 30 parts of 8020 copper-tin alloy powder, 10 parts of tungsten carbide, 15 parts of 1700 binder, and 30 parts of alcohol. Example 4

[0018] Preparation of cobalt-based metal dicing blades: The preparation method of this embodiment is the same as that of Example 1, except that the formulation amounts of each raw material are different, namely 4 parts of titanium-plated diamond, 57 parts of cobalt powder, 27 parts of 8020 copper-tin alloy powder, 9 parts of tungsten carbide, 14.5 parts of 1700 binder, and 27 parts of alcohol. Example 5

[0019] Preparation of cobalt-based metal dicing blades: The preparation method of this embodiment is the same as that of Example 1, except that: 1) the copper-tin 8020 powder is a mixed copper-tin powder of elemental composition, i.e., 8:2 copper-tin elemental composition; 2) the formulation amounts of each raw material are different, i.e.: 3.5 parts of titanium-plated diamond, 55 parts of cobalt powder, 25 parts of mixed copper-tin powder of elemental composition, 8 parts of tungsten carbide, 12.5 parts of 1700 binder and 25 parts of alcohol.

[0020] The cobalt-based metal dicing blades prepared in Examples 1-5 were tested using a Rockwell hardness tester. The test data is as follows: .

[0021] Five sets of commercially available metal scribing blades were tested using a Rockwell hardness tester, and the test data are as follows: .

[0022] In summary, the cobalt-based metal dicing blade obtained by this invention has a hardness up to three times that of commercially available metal dicing blades. It has high hardness, good wear resistance, high sharpness, good final cutting effect, and long service life.

Claims

1. A cobalt-based metal dicing blade, characterized in that, The cobalt-based metal dicing blade formulation includes the following components in parts by weight: 2-5 parts diamond, 50-60 parts cobalt powder, 20-30 parts copper-tin 8020 powder, 6-10 parts tungsten carbide, and 10-15 parts binder, wherein the diamond is titanium-plated diamond. The specific steps of the method for preparing the cobalt-based metal dicing blade are as follows: S1. After sieving the cobalt powder and copper-tin 8020 powder in the formula multiple times and mixing them evenly, add the tungsten carbide and diamond in the formula and stir evenly to obtain a metal powder mixture. S2. Dilute the binder of the specified amount with alcohol and stir well. Then mix it with the metal powder mixture. After it is completely wetted, add alcohol and send it into the three-dimensional mixer to mix evenly. S3. After removing the material from the three-dimensional mixer and drying it, granulation is completed by sieving it multiple times. S4. Weigh the granulated material according to the specifications of the cold pressing mold, put it into the cold pressing mold, and then demold it to obtain the dicing blade semi-finished product. S5. After the semi-finished dicing blade is sent into the sintering furnace for high-temperature hot pressing and sintering, it is cooled, demolded and finely processed to obtain the finished dicing blade. The specific operation process of high-temperature hot-pressing sintering in S5 is as follows: First, the blade is threaded onto a graphite sintering mandrel and placed inside a graphite sintering mold cavity; then, the sintering mold cavity is placed in the sintering furnace, the furnace door is closed and sealed, and a vacuum is drawn. After the pressure drops to 0.1 MPa, the sintering program is started; next, when the temperature reaches 350℃, it is held for 30 minutes and carbon removal is performed; finally, the temperature is continued to rise, and when the temperature reaches 650℃, a pressure of not less than 12T is applied, and the temperature is continued to rise to 700℃ and held for 30 minutes.

2. The cobalt-based metal dicing blade according to claim 1, characterized in that, The diamond is a D20 or D30 diamond.

3. The cobalt-based metal dicing blade according to claim 1, characterized in that, The cobalt powder has a particle size of 1–3 μm, the copper-tin 8020 powder has a particle size of 2–5 μm, and the tungsten carbide has a particle size of 6–10 μm.

4. The cobalt-based metal dicing blade according to claim 1, characterized in that, The copper-tin 8020 powder is a mixed powder of elemental copper and tin or a copper-tin alloy powder.

5. A cobalt-based metal dicing blade according to claim 1, characterized in that, In step S1, the sample is passed through a 300-mesh sieve at least 3 times; in step S3, the sample is passed through a 200-mesh sieve at least 3 times.

6. A cobalt-based metal dicing blade according to claim 1, characterized in that, In step S2, the mixing time of the three-dimensional mixer shall not be less than 1 hour.

7. A cobalt-based metal dicing blade according to claim 1, characterized in that, The amount of alcohol used is 20 to 30 parts.

8. A cobalt-based metal dicing blade according to claim 1, characterized in that, In step S4, the cold pressing pressure shall not be less than 500kN and the cold pressing time shall not be less than 3 seconds.