TWI468540B - Housing and method for making the same - Google Patents

Description

Housing and manufacturing method thereof

The present invention relates to a housing and a method of manufacturing the same.

Vacuum coating technology (PVD) is a very environmentally friendly film forming technology. The film formed by vacuum coating has the advantages of high hardness, high wear resistance, good chemical stability, strong bonding with the substrate and a beautiful metallic appearance. Therefore, the vacuum coating is applied to metal bases such as magnesium, magnesium alloy and stainless steel. The application of decorative surface treatment is becoming more and more extensive.

However, since the standard electrode potential of magnesium or magnesium alloy is very low, and the PVD decorative coating itself inevitably has tiny pores, such as pinholes, cracks, and magnesium and magnesium alloy substrates may cause micro-cell corrosion, forming A large membrane-base potential difference accelerates the corrosion rate of the microbattery. Therefore, plating a PVD decorative coating such as a TiN layer, a TiN layer, or a CrN layer directly on the surface of the magnesium or magnesium alloy substrate cannot effectively prevent it. The magnesium or magnesium alloy substrate undergoes electrochemical corrosion, and the PVD decorative coating itself may also undergo coloring, falling off, and the like.

In view of this, a housing having a good corrosion resistance and a decorative appearance is provided.

In addition, a method of manufacturing the above casing is also provided.

A casing comprising a magnesium or magnesium alloy substrate, an anticorrosive layer formed on a surface of the magnesium or magnesium alloy substrate, and a color layer formed on a surface of the anticorrosive layer, the anticorrosive layer comprising a magnesium or magnesium alloy substrate sequentially formed The magnesium layer and the magnesium oxide layer on the surface.

A method of manufacturing a housing, comprising the steps of:

Providing a magnesium or magnesium alloy matrix;

Magnetron sputtering an anti-corrosion layer on the magnesium or magnesium alloy substrate, the anti-corrosion layer comprising a magnesium layer and a magnesium oxide layer sequentially formed on a surface of the magnesium or magnesium alloy substrate;

A color layer is magnetron sputtered on the anti-corrosion layer.

In the method of manufacturing the casing, an anti-corrosion layer and a decorative color layer are sequentially formed on the magnesium or magnesium alloy substrate by magnetron sputtering. The anti-corrosion layer comprises a magnesium layer and a magnesium oxide layer which are sequentially formed on the surface of the magnesium or magnesium alloy substrate. When the shell is in a corrosive medium, the shell is slowed down due to the small potential difference between the magnesium and the magnesium alloy. The rate at which the microbial corrosion occurs in the body increases the corrosion resistance of the casing. While the corrosion resistance of the casing is improved, the color layer may be prevented from being colored, falling off, etc., so that the casing has a good decorative appearance after being used for a long time.

Referring to FIG. 1, a housing 10 according to a preferred embodiment of the present invention includes a magnesium or magnesium alloy substrate 11, an anti-corrosion layer 13 and a color layer 15 sequentially formed on the magnesium or magnesium alloy substrate 11. The casing 10 may be a casing of a 3C electronic product, or may be a component of a vehicle such as an industrial, a building, or an automobile.

The anti-corrosion layer 13 includes a magnesium layer 131 formed on the surface of the substrate 11 and a magnesium oxide layer 133 formed on the surface of the magnesium layer 131. The magnesium layer 131 has a thickness of 1.0 to 3.0 μm; and the magnesium oxide layer 133 has a thickness of 0.5 to 1.0 μm.

The color layer 15 is a Ti-N layer having a thickness of 1.0 to 3.0 μm. It can be understood that the color layer 15 can also be a Cr-N layer or other decorative film layer.

The method for manufacturing the housing 10 according to a preferred embodiment of the present invention mainly includes the following steps:

A magnesium or magnesium alloy substrate 11 is provided, and the magnesium or magnesium alloy substrate 11 is sequentially ground and electrolytically polished. After electrolytic polishing, the surface of the magnesium or magnesium alloy substrate 11 is wiped with deionized water and absolute ethanol in this order. Further, the wiped magnesium or magnesium alloy substrate 11 is placed in an ultrasonic cleaner containing an acetone solution for vibration cleaning to remove impurities, oil stains, and the like on the surface of the magnesium or magnesium alloy substrate 11. After cleaning, blow dry and set aside.

The surface of the magnesium or magnesium alloy substrate 11 subjected to the above treatment is subjected to argon plasma cleaning to further remove the oil stain on the surface of the magnesium or magnesium alloy substrate 11 to improve the adhesion of the surface of the magnesium or magnesium alloy substrate 11 to the subsequent coating. The specific operation and process parameters of the plasma cleaning may be: placing the magnesium or magnesium alloy substrate 11 into a coating chamber of a magnetron sputtering coating machine (not shown), and vacuuming the coating chamber to a vacuum degree of 1.0×10 ^-3 Pa, argon gas with a purity of 99.999% was introduced into the coating chamber at a flow rate of 250 to 500 sccm (standard state ML/min), and a bias of -300 to -800 V was applied to the magnesium or magnesium alloy substrate 11. Pressing, the surface of the magnesium or magnesium alloy substrate 11 is plasma-cleaned, and the cleaning time is 3 to 10 minutes.

After the magnesium or magnesium alloy substrate 11 is plasma-cleaned, an anti-corrosion layer 13 is formed on the magnesium or magnesium alloy substrate 11. First, the magnesium layer 131 in the anti-corrosion layer 13 is formed. The specific operation and process parameters for forming the magnesium layer 131 are as follows: argon gas is used as the working gas, the argon gas flow rate is adjusted to 100-300 sccm, the duty ratio is set to 50%-80%, and the magnesium or magnesium alloy substrate 11 is applied - 50~-100V bias, and heat the coating chamber to 80~120°C (ie, the sputtering temperature is 80~120°C); select magnesium as the target, set the power to 8~13kw, and deposit the anti-corrosion layer 13. The time for depositing the anti-corrosion layer 13 is 30 to 60 min.

After the magnesium layer 131 is formed, a magnesium oxide layer 133 is formed on the magnesium layer 131, and argon gas is used as a sputtering gas, and an argon gas flow rate is set to 100 to 300 sccm, and oxygen gas is used as a reaction gas, and an oxygen flow rate is set to 50 to 100 sccm. The duty ratio is 50-80%, a bias voltage of -50~-100V is applied to the magnesium and magnesium alloy substrate 11, and the coating chamber is heated to 100-150 ° C (ie, the sputtering temperature is 100-150 ° C); The target is set to have a power of 5 to 8 kw and a magnesium oxide layer 133 is deposited. The time for depositing the magnesium oxide layer 133 is 20 to 40 minutes. The thickness of the magnesium oxide layer 133 is controlled to be 0.5 to 1.0 μm.

After the magnesium oxide layer 133 is formed, a color layer 15 is formed on the anti-corrosion layer 13, and the color layer 15 is a Ti-N film layer or a Cr-N film layer. The specific operation and process parameters for forming the Ti-N film layer or the Cr-N film layer are as follows: turning off the power of the magnesium target, turning on a power source of a titanium target or a chromium target placed in the coating machine, and setting The power is 8~10kw, the flow rate of the argon gas is kept unchanged, and a reaction gas nitrogen gas having a flow rate of 20 to 150 sccm is introduced into the coating chamber to deposit a color layer 15. The time for depositing the color layer 15 is 20 to 30 minutes.

In the method of manufacturing the casing 10 of the preferred embodiment of the present invention, the anticorrosive layer 13 and the color layer 15 are sequentially formed on the magnesium or magnesium alloy substrate 11 by magnetron sputtering. When the casing 10 is in a corrosive medium, since the potential difference between the magnesium and the magnesium oxide in the anti-corrosion layer 13 and the magnesium or magnesium alloy substrate 11 is small, the rate at which the micro-cell is corroded by the casing 10 is slowed down, thereby The corrosion resistance of the casing 10 is improved. While the corrosion resistance of the casing 10 is improved, the color layer 15 can be prevented from being in a state of discoloration, falling off, etc., so that the casing 10 has a good decorative appearance after being used for a long time.

10. . . case

11. . . Magnesium or magnesium alloy matrix

13. . . Anti-corrosion layer

131. . . Magnesium layer

133. . . Magnesium oxide layer

15. . . Color layer

1 is a schematic cross-sectional view of a housing in accordance with a preferred embodiment of the present invention.

10. . . case

11. . . Magnesium or magnesium alloy matrix

13. . . Anti-corrosion layer

131. . . Magnesium layer

133. . . Magnesium oxide layer

15. . . Color layer

Claims (9)

A casing comprising a magnesium or magnesium alloy substrate, an anticorrosive layer formed on a surface of the magnesium or magnesium alloy substrate, and a color layer formed on a surface of the anticorrosive layer, wherein the anticorrosive layer comprises a magnesium layer formed in turn Or a magnesium layer and a magnesium oxide layer on the surface of the magnesium alloy substrate. The casing according to claim 1, wherein the magnesium layer has a thickness of 1.0 to 3.0 μm. The casing according to claim 1, wherein the magnesium oxide layer has a thickness of 0.5 to 1.0 μm. The casing of claim 1, wherein the color layer is a Ti-N layer or a Cr-N layer. The casing of claim 1, wherein the anti-corrosion layer and the color layer are formed by a magnetron sputtering coating method. A method of manufacturing a housing, comprising the steps of:
Providing a magnesium or magnesium alloy matrix;
Magnetron sputtering an anti-corrosion layer on the magnesium or magnesium alloy substrate, the anti-corrosion layer comprising a magnesium layer and a magnesium oxide layer sequentially formed on a surface of the magnesium or magnesium alloy substrate;
A color layer is magnetron sputtered on the anti-corrosion layer. The method for manufacturing a casing according to claim 6, wherein the process parameter of the magnetron sputtering magnesium layer is: using argon as a working gas, the flow rate is 100~300 sccm, and the duty ratio is set to 50. %~80%, applying a bias voltage of -50~-100V on the magnesium or magnesium alloy substrate, using magnesium as the target, setting the power to 8~13kw, sputtering temperature 80~120°C, sputtering time 30 ~60min. The method for manufacturing a casing according to claim 6, wherein the process parameter of the magnetron sputtering magnesium oxide layer is: setting an argon gas flow rate of 100 to 300 sccm, using oxygen as a reaction gas, and setting the oxygen flow rate to 50~100sccm, set the duty ratio to 50~80%, apply a bias voltage of -50~-100V to the substrate, select magnesium as the target, set the power to 5~8kw, and deposit the magnesium oxide layer for 20~40min. . The method for manufacturing a casing according to claim 6, wherein the process parameter of the magnetron sputtering color layer is: turning on a power source of a titanium target or a chromium target, setting a power of 8 to 10 kW, and setting a nitrogen gas. The flow rate is 20~150sccm, and the sputtering time is 20~30min.