Surface treatment method of molybdenum alloy for heat sink material

Abstract

The application provides a surface treatment method of molybdenum alloy for heat sink material, and the surface treatment method comprises the following steps: completing the surface treatment process by sequentially performing oil removal treatment, cleaning treatment, grinding and drying treatment on the molybdenum alloy blank for heat sink material. The surface treatment method takes the high-temperature liquid-phase sintered molybdenum alloy as the raw material, adopts the ultrasonic oil removal, cleaning and grinding machine grinding mode to treat the surface of the molybdenum alloy, can reduce the surface roughness of the molybdenum alloy before electroplating and remove the burrs on the surface of the alloy, further improves the bonding force between the plating layer and the Mo alloy substrate, and can effectively improve the yield during electroplating.

Description

Technical Field

[0001] This invention belongs to the field of alloy surface treatment technology, and particularly relates to a surface treatment method for molybdenum alloys used in heat sink materials. Background Technology

[0002] Heat sink materials are specialized materials widely used in the packaging of various semiconductor chips and electronic power devices. These materials possess excellent electrical and thermal conductivity, as well as a low coefficient of thermal expansion. With the rapid increase in chip integration, ever-increasing power and smaller dimensions undoubtedly place higher demands on heat sink materials used for heat dissipation.

[0003] CN 114789365A discloses an alloy surface treatment method, which includes the following steps: (1) grinding and polishing the surface of the alloy to be processed; (2) cleaning the surface of the alloy to ensure that the alloy surface is free of dirt and grease; (3) drying the surface of the alloy to ensure that the alloy surface is free of water stains; (4) pickling and passivating the alloy to be processed.

[0004] CN 110359047A discloses a surface treatment method for aluminum alloys, which includes the following steps: alkaline etching of an aluminum alloy to form a first structural portion on the surface of the aluminum alloy, the first structural portion including a plurality of uniformly distributed first grooves; water washing of the aluminum alloy; acid etching of the aluminum alloy to form a second structural portion, the second structural portion including a plurality of second grooves uniformly distributed on the first structural portion. The aluminum alloy surface treated by this invention has a uniform, delicate, white, and atomized appearance. The aluminum alloy surface treatment method of this invention uses a low concentration of chemical reagents, and the corrosion amount on the aluminum alloy is less than 5%, avoiding damage to the aluminum alloy dimensions. The aluminum alloy surface treatment method of this invention avoids the use of fluoride ion-containing reagents, making processing and production safer. In this method, the invention only provides acid pickling protection for the alloy, lacking a complete pretreatment process for the alloy, which affects the treatment effect of the alloy and needs to be improved.

[0005] None of the aforementioned patents provide a surface treatment process for molybdenum alloys. Currently, conventional pre-plating processes for Mo alloys include, but are not limited to, polishing and sandblasting. Polished Mo alloys offer advantages such as low surface roughness and high cleanliness, but this process is time-consuming and inefficient, making it suitable only for prototype production and not for mass production. Sandblasting results in a short production cycle and high efficiency for Mo alloys; however, it also results in higher surface roughness, which can lead to adhesion problems between the plating layer and the substrate after subsequent electroplating.

[0006] In summary, providing an efficient surface treatment process for molybdenum alloys is one of the urgent problems to be solved in this field. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a surface treatment method for molybdenum alloys used in heat sink materials. This surface treatment method employs ultrasonic degreasing, cleaning, and grinding to treat the molybdenum alloy surface. This reduces the surface roughness of the molybdenum alloy before electroplating and removes burrs from the alloy surface, further improving the adhesion between the plating layer and the molybdenum alloy substrate, thereby effectively increasing the yield during electroplating.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] This invention provides a surface treatment method for molybdenum alloys used in heat sink materials, the surface treatment method comprising the following steps:

[0010] The surface treatment process is completed by sequentially performing degreasing, cleaning, grinding and drying on the molybdenum alloy blank used for heat sink materials.

[0011] The surface treatment method provided by this invention can effectively reduce the surface roughness of molybdenum alloy blanks and remove burrs from the alloy surface through degreasing, cleaning and grinding; it can further improve the adhesion between the coating and the molybdenum alloy substrate and effectively improve the yield during electroplating.

[0012] As a preferred embodiment of the present invention, the degreasing treatment includes: placing the heat sink material, a molybdenum alloy blank, into a degreasing agent for ultrasonic treatment.

[0013] As a preferred embodiment of the present invention, the degreasing agent comprises an aqueous solvent of sodium benzenesulfonate and sodium sulfate.

[0014] Preferably, the volume ratio of sodium benzenesulfonate, sodium sulfate and water is (1-1.5):(1-1.5):(2-3), for example, it can be 1:1:2, 1.5:1.5:2, 1:1.5:2, 1:1.5:3, 1.5:1:2 or 1.5:1:3, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0015] Preferably, the frequency of the first ultrasonic treatment is 30 to 50 kHz, for example, 34 kHz, 38 kHz, 42 kHz or 46 kHz, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] The degreasing agent of this invention removes oil by disrupting the structure of the oil stains through a chemical reaction with the proteins and lipids in the grease and oil. This reaction breaks down the grease and oil stains into smaller molecules, making them easier to clean.

[0017] The degreasing agent of this invention contains sodium benzenesulfonate and sodium sulfate. Sodium sulfate has a sulfate group, and sodium benzenesulfonate has a benzenesulfonic acid group. These surfactants can chemically react with the proteins and lipids in grease and oil stains, causing them to decompose into smaller molecules. The synergistic effect of the two can better decompose the oil stains on the surface of the molybdenum alloy into smaller molecules, so that the grease and oil stains can be washed away by the aqueous solution, resulting in a cleaner surface.

[0018] Preferably, the duration of one ultrasound treatment is 20 to 30 minutes, for example, 22 minutes, 24 minutes, 26 minutes or 28 minutes, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0019] The ultrasonic treatment time described in this invention is 20 to 30 minutes. If the time is too long, it will waste production capacity and increase the processing cost; if it is too short, the cleaning will not be thorough and will affect the surface treatment effect of the molybdenum alloy.

[0020] As a preferred embodiment of the present invention, the cleaning process includes: placing the degreased molybdenum alloy billet into isopropanol for secondary ultrasonic treatment.

[0021] As a preferred embodiment of the present invention, the concentration of isopropanol is ≥99.99%, for example, it can be 99.992%, 99.994%, 99.996% or 99.998%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0022] Preferably, the frequency of the secondary ultrasonic treatment is 30-50 kHz, for example, 34 kHz, 38 kHz, 42 kHz or 46 kHz, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0023] Preferably, the duration of the secondary ultrasound treatment is 5 to 10 minutes, for example, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0024] The purpose of the cleaning process described in this invention is to: (1) remove the degreasing agent residue from the surface of the molybdenum alloy; and (2) accelerate the rapid dehydration and drying of the material.

[0025] As a preferred embodiment of the present invention, the abrasive used in the grinding process includes alumina particles.

[0026] In the grinding process described in this invention, the particle size of the grinding material is smaller than the size of the product to be ground, in order to facilitate the sorting of the product to be ground.

[0027] Preferably, the rotational speed during grinding is 40 to 50 r / min, for example, it can be 42 r / min, 44 r / min, 46 r / min or 48 r / min, but is not limited to the listed values. Other values ​​not listed within the range are also applicable.

[0028] Preferably, the grinding time is 20 to 40 minutes, for example, 22 minutes, 26 minutes, 30 minutes, 34 minutes or 38 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] The purpose of the grinding described in this invention is to: (1) remove the rolling stress layer on the alloy surface and the burrs generated during the processing; (2) thoroughly clean the material surface from all angles without dead angles; if the rotation speed is too high during the grinding process, the centrifugal force will be too large, which will cause the material to stick to the grinding barrel, thus failing to achieve the grinding effect; if the rotation speed is too low, the abrasive and the material itself will have a smaller collision strength, and the cleaning and deburring will not be thorough.

[0030] As a preferred embodiment of the present invention, the drying process includes vacuum drying.

[0031] Preferably, the vacuum drying temperature is 60-80°C, for example, 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C or 78°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0032] Preferably, the vacuum drying time is 30 to 50 minutes, for example, 32 minutes, 34 minutes, 36 minutes, 38 minutes, 40 minutes, 42 minutes, 44 minutes, 46 minutes or 48 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0033] Preferably, the vacuum degree of the vacuum drying does not exceed 0.01 Pa, for example, it can be 0.01 Pa, 0.008 Pa, 0.006 Pa, 0.004 Pa or 0.002 Pa, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0034] As a preferred embodiment of the present invention, the surface treatment method for molybdenum alloy heat sink materials provided by the present invention includes the following steps:

[0035] The heat sink material is placed in a degreasing agent and subjected to a first ultrasonic treatment at a frequency of 30-50 kHz for 20-30 minutes. Then, it is placed in isopropanol with a concentration of ≥99.99% and subjected to a second ultrasonic treatment at a frequency of 30-50 kHz for 5-10 minutes.

[0036] Then, using alumina particles as abrasive, the surface is ground at a speed of 40-50 r / min for 20-40 min; and then vacuum dried at 60-80℃ and a vacuum degree not exceeding 0.01 Pa for 30-50 min to complete the surface treatment process.

[0037] The degreasing agent comprises an aqueous solvent of sodium benzenesulfonate and sodium sulfate, wherein the volume ratio of sodium benzenesulfonate, sodium sulfate and water is (1-1.5):(1-1.5):(2-3).

[0038] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] The surface treatment method provided by this invention can reduce the surface roughness of molybdenum alloys, remove burrs from the alloy surface, improve the adhesion between the coating and the molybdenum alloy substrate, and effectively improve the yield during electroplating. Detailed Implementation

[0041] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0042] Example 1

[0043] This embodiment provides a surface treatment method for molybdenum alloys used in heat sink materials, the surface treatment method including the following steps:

[0044] The heat sink material was placed in a degreasing agent and subjected to a first ultrasonic treatment at a frequency of 40 kHz for 25 minutes, and then placed in 99.6% isopropanol and subjected to a second ultrasonic treatment at a frequency of 40 kHz for 8 minutes.

[0045] Then, using alumina particles as abrasive, the surface was ground at 45 r / min for 30 min; and then vacuum dried at 70℃ and 0.008 Pa for 40 min to complete the surface treatment process.

[0046] The degreasing agent comprises an aqueous solvent of sodium benzenesulfonate and sodium sulfate, wherein the volume ratio of sodium benzenesulfonate, sodium sulfate and water is 1.25:1.25:2.5.

[0047] Example 2

[0048] This embodiment provides a surface treatment method for molybdenum alloys used in heat sink materials, the surface treatment method including the following steps:

[0049] The heat sink material was placed in a degreasing agent and subjected to a first ultrasonic treatment at a frequency of 50 kHz for 20 minutes, and then placed in 99.996% isopropanol and subjected to a second ultrasonic treatment at a frequency of 50 kHz for 5 minutes.

[0050] Then, using alumina particles as abrasive, the surface was ground at 40 r / min for 40 min; and then vacuum dried at 60℃ and 0.01 Pa for 50 min to complete the surface treatment process.

[0051] The degreasing agent comprises an aqueous solvent of sodium benzenesulfonate and sodium sulfate, wherein the volume ratio of sodium benzenesulfonate, sodium sulfate and water is 1:1:3.

[0052] Example 3

[0053] This embodiment provides a surface treatment method for molybdenum alloys used in heat sink materials, the surface treatment method including the following steps:

[0054] The heat sink material was placed in a degreasing agent and subjected to a first ultrasonic treatment at a frequency of 30 kHz for 30 minutes, and then placed in 99.99% isopropanol and subjected to a second ultrasonic treatment at a frequency of 30 kHz for 10 minutes.

[0055] Then, using alumina particles as abrasive, the surface was ground at 50 r / min for 20 min; and then vacuum dried at 80℃ and 0.006 Pa for 30 min to complete the surface treatment process.

[0056] The degreasing agent comprises an aqueous solvent of sodium benzenesulfonate and sodium sulfate, wherein the volume ratio of sodium benzenesulfonate, sodium sulfate and water is 1.5:1.5:2.

[0057] Example 4

[0058] This embodiment provides a surface treatment method for molybdenum alloys used in heat sink materials, the surface treatment method including the following steps:

[0059] The heat sink material was placed in a degreasing agent and subjected to a first ultrasonic treatment at a frequency of 35 kHz for 26 minutes, and then placed in 99.992% isopropanol and subjected to a second ultrasonic treatment at a frequency of 42 kHz for 6 minutes.

[0060] Then, using alumina particles as abrasive, the surface was ground at 43 r / min for 32 min; and then vacuum dried at 67℃ and 0.01 Pa for 42 min to complete the surface treatment process.

[0061] The degreasing agent comprises an aqueous solvent of sodium benzenesulfonate and sodium sulfate, wherein the volume ratio of sodium benzenesulfonate, sodium sulfate and water is 1.5:1:2.5.

[0062] Example 5

[0063] This embodiment provides a surface treatment method for molybdenum alloys used as heat sink materials. The only difference between this surface treatment method and that of Embodiment 1 is:

[0064] In this embodiment, the degreasing agent is modified to sodium benzenesulfonate.

[0065] Example 6

[0066] This embodiment provides a surface treatment method for molybdenum alloys used as heat sink materials. The only difference between this surface treatment method and that of Embodiment 1 is:

[0067] In this embodiment, the degreasing agent is modified to sodium sulfate.

[0068] Example 7

[0069] This embodiment provides a surface treatment method for molybdenum alloys used as heat sink materials. The only difference between this surface treatment method and that of Embodiment 1 is:

[0070] In this embodiment, the time for one ultrasound treatment is modified to 15 minutes.

[0071] Example 8

[0072] This embodiment provides a surface treatment method for molybdenum alloys used as heat sink materials. The only difference between this surface treatment method and that of Embodiment 1 is:

[0073] In this embodiment, the time for the secondary ultrasound treatment is modified to 3 minutes.

[0074] Example 9

[0075] This embodiment provides a surface treatment method for molybdenum alloys used as heat sink materials. The only difference between this surface treatment method and that of Embodiment 1 is:

[0076] In this embodiment, the grinding speed is modified to 35 r / min.

[0077] Example 10

[0078] This embodiment provides a surface treatment method for molybdenum alloys used as heat sink materials. The only difference between this surface treatment method and that of Embodiment 1 is:

[0079] In this embodiment, the grinding speed is modified to 55 r / min.

[0080] Comparative Example 1

[0081] This comparative example provides a surface treatment method for a molybdenum alloy used as a heat sink material. The only difference between this surface treatment method and Example 1 is that:

[0082] The degreasing process is omitted in this comparative example.

[0083] Comparative Example 2

[0084] This comparative example provides a surface treatment method for a molybdenum alloy used as a heat sink material. The only difference between this surface treatment method and Example 1 is that:

[0085] This comparative example omits the cleaning process.

[0086] Comparative Example 3

[0087] This comparative example provides a surface treatment method for a molybdenum alloy used as a heat sink material. The only difference between this surface treatment method and Example 1 is that:

[0088] This comparative example replaces the grinding process with polishing.

[0089] The molybdenum alloy obtained by the surface treatment methods provided in the above embodiments and comparative examples was subjected to surface roughness and appearance inspection. The treated alloy and the coating were then electroplated to further examine the electroplating yield. The results are shown in Table 1.

[0090] The coating includes any one of Ni, Cu, or Au layers. The coating is related to the final application of the product, and the present invention does not specifically limit the type of coating.

[0091] Table 1

[0092]

[0093]

[0094] Analysis of Table 1 reveals the following points:

[0095] (1) Comprehensive analysis of Examples 1-4 shows that the surface treatment method provided by the present invention can reduce the surface roughness of molybdenum alloy, remove burrs from the alloy surface, improve the bonding force between the coating and the molybdenum alloy substrate, and effectively improve the yield during electroplating.

[0096] (2) Comprehensive analysis of Examples 1, 5 and 6 shows that the degreasing agent of the present invention, either sodium benzenesulfonate or sodium sulfate, will affect the electroplating yield of molybdenum alloy. This indicates that only by using sodium benzenesulfonate and sodium sulfate in combination can better results be achieved, further demonstrating the synergistic effect of the two.

[0097] (3) Comprehensive analysis of Examples 1, 7 and 8 shows that both the ultrasonic time during the degreasing process and the ultrasonic time during the isopropanol cleaning process will affect the electroplating yield of molybdenum alloys. If the processing time is too short, the cleaning effect will be poor.

[0098] In summary, the surface treatment method provided by this invention uses Mo alloy synthesized at high temperature liquid phase as raw material, and treats the Mo alloy surface by ultrasonic degreasing, cleaning and grinding. This can reduce the surface roughness of the Mo alloy before electroplating and remove burrs from the alloy surface, further improving the adhesion between the coating and the Mo alloy substrate, and effectively improving the yield during electroplating.

[0099] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A surface treatment method for a molybdenum alloy for heat sink material, characterized by, The surface treatment method comprises the following steps: The surface treatment process is completed after the molybdenum alloy blank for heat sink material is sequentially subjected to oil removal treatment, cleaning treatment, grinding and drying treatment; The oil removal agent comprises an aqueous solution of sodium benzenesulfonate and sodium sulfate; The volume ratio of the sodium benzenesulfonate, the sodium sulfate and water is (1-1.5):(1-1.5):(2-3); The rotating speed in the grinding is 40-50 r / min; The grinding time is 20-40 min; If the rotating speed in the grinding is too high, the centrifugal force is large, which causes the material to adhere to the grinding barrel, so that the grinding effect cannot be achieved, and if the rotating speed is too low, the collision strength of the grinding material and the material itself is small, so that the cleaning and deburring are not complete.

2. The surface treatment method according to claim 1, characterized by, The oil removal treatment comprises: placing the molybdenum alloy blank for heat sink material into the oil removal agent for one-time ultrasonic treatment.

3. The surface treatment method according to claim 2, characterized by, The frequency of the one-time ultrasonic treatment is 30-50 KHz.

4. The surface treatment method according to claim 2, characterized by, The one-time ultrasonic treatment time is 20-30 min.

5. The surface treatment method according to claim 1, characterized by, The cleaning treatment comprises: placing the molybdenum alloy blank after the oil removal treatment into isopropyl alcohol for two-time ultrasonic treatment.

6. The surface treatment method according to claim 5, wherein The concentration of the isopropyl alcohol is ≥99.99%.

7. The surface treatment method according to claim 5, wherein The frequency of the two-time ultrasonic treatment is 30-50 KHz.

8. The surface treatment method according to claim 5, wherein The two-time ultrasonic treatment time is 5-10 min.

9. The surface treatment method according to claim 1, characterized by, The grinding material used in the grinding comprises alumina particles.

10. The surface treatment method according to claim 1, characterized by, The drying treatment comprises vacuum drying.

11. The surface treatment method according to claim 10, wherein The temperature of the vacuum drying is 60-80℃.

12. The surface treatment method according to claim 10, wherein The vacuum drying time is 30-50 min.

13. The surface treatment method according to claim 10, wherein The vacuum degree of the vacuum drying is not more than 0.01 Pa.

14. The surface treatment method according to any one of claims 1 to 13, characterized by, The surface treatment method comprises the following steps: placing the molybdenum alloy blank for heat sink material into the oil removal agent for one-time ultrasonic treatment at a frequency of 30-50 KHz for 20-30 min, and then placing the molybdenum alloy blank into isopropyl alcohol with a concentration of ≥99.99% for two-time ultrasonic treatment at a frequency of 30-50 KHz for 5-10 min; then, using alumina particles as the grinding material, grinding at a rotating speed of 40-50 r / min for 20-40 min, and then vacuum drying at a temperature of 60-80℃ and a vacuum degree of not more than 0.01 Pa for 30-50 min to complete the surface treatment process; The oil removal agent comprises an aqueous solution of sodium benzenesulfonate and sodium sulfate, and the volume ratio of the sodium benzenesulfonate, the sodium sulfate and water is (1-1.5):(1-1.5):(2-3).

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