Patent Application
20230226610
The present disclosure relates to a method for manufacturing a target material, and more particularly, to a method for forming a target material in a lamination manufacturing process and rapidly solidifying the formed target material.
Sputtering is a physical vapor deposition technique, which is used to deposit a set target material on a surface of a target object to form a thin film of a material corresponding to the target material. For example, in an application of components of computer equipment, an alloy sputtering target material formed of iron, cobalt, chromium and boron can be used to apply to a soft magnetic layer on a hard disk drive (HDD), wherein a thickness of the soft magnetic layer is almost a sum of thicknesses of the other film layers, and the soft magnetic layer is the target material with the greatest demand.
In the process of applying sputtering, a quality of the target material used often determines a quality of a sputtering result. In the past two decades, the production of the target material has evolved from the Vacuum Induction Melting (VIM) process, which has been replaced by conventional Powder Metallurgy (PM). The target material produced by the PM process has fine grains, which has the advantage of improving the performance of the sputtering film. Therefore, the current sputtering target material is usually produced by the PM process. However, in the conventional target material manufacturing process, the problem of boron precipitation is prone to occur, which will cause the problem of poor target material quality. Furthermore, the conventional target material manufacturing process has the problems of high labor and power costs, long man-hours, distortion and deformation of important parts of the sintered body, and loss of post-processing materials.
From the above, it can be seen that how to provide a better method for manufacturing a target material is really important to prevent boron precipitation (which affects the quality of the target material), reduce manufacturing costs and man-hours, and reduce other problems that cause poor quality of the target material during the manufacturing process. Therefore, how to overcome the above-mentioned flaws of the prior art has become an urgent issue to be solved at present.
In view of the various deficiencies of the prior art, the present disclosure provides a method for manufacturing a target material, which is performed by a computer equipment, comprising the following steps: installing a substrate; spreading a raw material powder on the substrate by a scraper to form a powder layer; melting the raw material powder of the powder layer by a laser according to a plane size of the target material; forming another powder layer on the substrate and the melted raw material powder; melting a raw material powder of the another powder layer by the laser to form a desired height of the target material according to the plane size of the target material; and cooling the target material. In one embodiment, the target material can be a hard disk sputtering target material.
In one embodiment, the raw material powder is a powder including iron, cobalt, chromium and boron.
In another embodiment, before the step of forming the powder layer on the substrate, the present disclosure further comprises the following steps: performing a coarse screening for a coarse powder screening of the raw material powder via a coarse screen to obtain the raw material powder in fine powder form; and performing a fine screening for a fine powder screening of the raw material powder via a fine screen to obtain the raw material powder with a particle size of about 20 μm to 70 μm and a powder flowability of less than 16%.
In another embodiment, the coarse screening for the coarse powder screening and the fine screening for the fine powder screening are performed by an oscillating screen equipment.
In another embodiment, the raw material powder is stored in a powder feeding tank, and the step of forming the powder layer on the substrate is to make the scraper sequentially take out the raw material powder from the powder feeding tank that is enough to lay flat on the substrate to form the powder layer.
In another embodiment, the laser has a power of 140 W and a scanning speed of 900 mm/s.
In another embodiment, the substrate is installed in a construction cabin, and the steps of forming the powder layer on the substrate, melting the powder layer by the laser and cooling the target material are performed in the construction cabin.
In another embodiment, the construction cabin is filled with inert gas or nitrogen gas.
In another embodiment, the scraper and a surface of the substrate are kept parallel to each other with a thickness formed by the powder layer as a distance.
In a further embodiment, before performing the step of installing the substrate, the present disclosure further comprises the following steps: grinding a surface of the substrate.
To sum up, the manufacturing method of the target material according to the present disclosure is to repeatedly perform, through a manner of lamination manufacturing, the steps of laying a raw material powder on a substrate to form a powder layer and melting the powder layer by a laser, so as to form a target material, and finally, the target material is rapidly cooled to achieve the purpose of improving the density and quality of the target material, and can achieve the effect of preventing boron precipitation. Further, the present disclosure manufactures a target material by using a lamination manufacturing process to melt a raw material powder at a high temperature by a laser and rapidly solidify the target material, so that the produced target material has a finer and more uniform microstructure of a hard disk target, in order to provide better film characteristics and sputtering efficiency. For example, when making hard disk discs, it is more helpful to control the quality of the disc.
The following describes the implementation of the present disclosure with examples. Those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. However, the present disclosure can also be implemented or applied by other different embodiments.
As shown in
As shown in
In addition, before installing the substrate 11, a pre-operation can be performed in advance, and the steps of the pre-operation are described as follows.
First, prepare the substrate 11, that is, the surface of the substrate 11 is ground. If the substrate 11 has been subjected to the manufacturing process of the target material, the previously printed product of the target material is first removed from the substrate 11, and then a surface grinder is used to grind an upper and a lower planes of the substrate to obtain the substrate 11 with better flatness and parallelism, so as to reduce the variation factors of subsequent printing production.
Furthermore, in order to clean the processing machine 1, an anti-static brush is used to remove raw material powder left over from the previous manufacturing process of the target material in the processing machine 1, and then a wiping paper is used in combination with anhydrous alcohol for cleaning.
Also, the scraper 14 may be cleaned or replaced. If it is only for cleaning the scraper 14, anhydrous alcohol may be used to clean the surface of the scraper 14, so as to prevent residual powder on a contact surface contacting the raw material powder, causing the scraper 14 to be uneven; if the scraper 14 is to be replaced, the scraper 14 must be removed first, the raw material powder adhering on the surface of the scraper 14 must be removed with a brush, and after removing an upper base (not shown), which is for the scraper 14 to be installed, on the processing machine 1 and the scraper 14, it must also be cleaned with anhydrous alcohol to prevent powder residue on the contact surface, which may cause the scraper 14 to be installed unevenly.
In step S102, a raw material powder 2 is provided, and then the raw material powder 2 is spread on the substrate 11 by the scraper 14 to form a powder layer 21. The raw material powder 2 may include a mixed powder of iron powder, cobalt powder, chromium powder and boron powder. As shown in
In one embodiment, before the raw material powder 2 is provided, the raw material powder 2 can be screened to obtain a better raw material powder 2, and the quality of the produced target material can be improved accordingly. For instance, the present disclosure utilizes an oscillating screen equipment to perform a screening of the raw material powder 2. The steps of screening the raw material powder 2 are described as follows.
Coarse powder screening is to coarsely screen the raw material powder through a coarse screen to obtain a fine powdery raw material powder 2. That is, through the screen, a mechanical oscillating screen is used to screen out the powder with excessive particle size (for example, the powder with a particle size larger than 70 μm), and when the raw material powder has agglomeration phenomenon, the agglomerated raw material is divided into pieces for coarse screening. For example, the initial raw material powder 2 may include agglomerates, granules, or powders with larger particle size, so they are screened out by a screen with a mesh smaller than the aforementioned powders with larger particle size, so as to retain the fine powdery raw material powder 2.
Fine powder screening is to finely screen the raw material powder 2 in a fine powder form through a fine screen to obtain the raw material powder 2 with a particle size of about 20 μm to 70 μm and a powder flowability of less than 16%. For instance, in the present disclosure, a cyclone powder classifier can be used to screen the fine powder with too small particle size by a centrifugal force, so as to ensure the processing quality of the subsequent procedures.
In step S103, a laser melting is performed. It uses a laser 16 to melt the powder layer according to a plane size of the target material, and the plane size of the target material is a size parameter of a top view plane of the target material. For example, when the target material is in the shape of a square cake, its plane size is a side length or parameters of a length and a width of the square cake-shaped target material. In another embodiment, as shown in
In step S104, in order to achieve a desired height size of the target material 3, the supply of the raw material powder and the laser melting are performed repeatedly, that is, the steps of providing another powder layer and melting a raw material powder of the another powder layer with the laser according to the plane size of the target material are continuously performed on the substrate and the melted raw material powder (that is, the target material layer 22 that has been formed). As shown in
In step S105, the target material is cooled. Preferably, the target material 3 can be rapidly cooled, so that the target material 3 is rapidly solidified. For instance, the present disclosure performs cooling of the target material 3 at a high cooling rate of 106° C./sec, so that the target material 3 is rapidly solidified. Moreover, the cooling rate can be controlled through parameters such as the laser scanning rate, that is, by optimizing the laser parameters, to confirm an optimal cooling rate for refining the target grains, so as to prevent the precipitation of boron materials.
As shown in
In an embodiment, the processing machine 1 according to the present disclosure may include a construction cabin (not shown) for providing a processing operation environment, and the construction cabin is a closed cabin that can be filled with inert gas or nitrogen gas, and includes a hatch for the user to operate. Therefore, the substrate 11 is installed in the construction cabin, and the steps of supplying raw material powder, laser melting and cooling the target material are performed in the construction cabin, so the manufacturing method of the target material according to the present disclosure can be carried out in an automated manner via the processing machine 1 having the construction cabin. That is, after installing the substrate 11 and adding enough raw material powder 2 for processing into the powder feeding tank 15, the following steps are performed.
First, a step of closing the hatch is performed. That is, after the hardware setting (such as installing the substrate, adding raw material powder) has been completed, the hatch of the construction cabin is closed, and then nitrogen gas is input and the substrate 11 is heated until it reaches the set condition (such as 150° C.), so that the preparation for being able to print (i.e., making the target material) at any time is completed. In one embodiment, the processing machine 1 includes a computer equipment for inputting set parameters for automatic control, so as to allow the user to input the parameters required for the manufacturing method of the target material according to the present disclosure (for example, the power, scanning speed, etc. of the above-mentioned laser).
Then, a step of preparing a drawing is performed. The user first uses a drawing software to complete a 3D (three-dimensional) geometry of the desired product, and then imports it into a software corresponding to the computer equipment of the processing machine 1 for subsequent settings.
Finally, a step of setting the software is performed. After the drawing is prepared and imported into the computer equipment of the processing machine 1, it is necessary to determine the position of the substrate and set the printing parameters, the parameters include the thickness of the powder layer, the temperature of the substrate, the laser power, and the scanning rate, etc.
In an embodiment, the present disclosure can utilize a selective laser melting (SLM) equipment to set the above-mentioned parameters and perform the above-mentioned steps.
Therefore, the present disclosure can be applied to a processing process of a sputtering target material of iron cobalt chromium boron alloy. The processing process uses a screening machine to obtain raw material powder 2 with appropriate particle size (such as a particle size of about 20 μm to 70 μm and a powder flowability of less than 16%). Then, appropriate parameters (such as 140 W laser power, or 900 mm/s laser scanning speed) are selected to make the raw material powder 2 into the target material 3 by the processing machine 1, and then the target material 3 is tempered and reprocessed in the subsequent process. Therefore, the present disclosure utilizes the uniqueness of the process of rapidly solidifying the raw material powder 2 after melting to form a target material, which can effectively increase the density of the target material and reduce the precipitation phase of boride. That is, the present disclosure is a rapid solidification process (RSP) in the manner of lamination manufacturing through a laser, so it can improve an alloy adding ability and refine the microstructure. Furthermore, compared with the conventional powder metallurgy process, the present disclosure can make the microstructure of the target material 3 more detailed, uniform and dense, improve the quality of the sputtering target material and form a sputtering film with better performance, and can achieve the purpose of maximizing the service life of the target material 3. The present disclosure utilizes the advantages of the One Net Shape Forming process of the lamination manufacturing process, which can further reduce the loss of the material post-processing process, and can reduce the manufacturing process, and also has the commercialization capability of single-batch mass production of target materials. Therefore, compared with the conventional powder metallurgy process, the manufacturing method according to the present disclosure can greatly reduce the production cost.
To sum up, the manufacturing method of the target material according to the present disclosure is to repeatedly perform, through a manner of lamination manufacturing, the steps of laying a raw material powder 2 on a substrate 11 to form a powder layer 21 and melting the powder layer 21 by a laser, so as to form a target material, and finally, the target material 3 is rapidly cooled to achieve the purpose of improving the density and quality of the target material 3, and can achieve the effect of preventing boron precipitation. In other words, the present disclosure manufactures a target material by using a lamination manufacturing process to melt a raw material powder at a high temperature by a laser and rapidly solidify the target material, so that the produced target material has a finer and more uniform microstructure of a hard disk target, in order to provide better film characteristics and sputtering efficiency. For example, when making hard disk discs, it is more helpful to control the quality of the disc. In addition, although the present disclosure is described with the processing equipment performing the above steps of the present disclosure, the processing equipment is not limited to the above.
The foregoing embodiments are provided for the purpose of illustrating the principles and effects of the present disclosure, rather than limiting the present disclosure. Anyone skilled in the art can modify and alter the above embodiments without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection with regard to the present disclosure should be as defined in the accompanying claims listed below.
| Number | Date | Country | Kind |
|---|---|---|---|
| 111102011 | Jan 2022 | TW | national |
