JP2008088469A - Copper alloy-made backing plate, and method for manufacturing copper alloy for backing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper alloy-made backing plate which has, particularly excellent characteristics to oxidizing resistance adaptable to the requiement of upsizing the backing plate and also an excellent machineability in addition to characteristics convenyionally desired to the backing plate (e.g. heat-conductivity, mechanical strength and heat-resistance), and to provide a method for manufacturing the copper alloy for backing plate. <P>SOLUTION: In the copper alloy for backing plate, a copper alloy cast block containing 0.1-3.0 mass% Fe, 0.001-0.1 mass% P, 0.01-1.0 mass% Zn, 0.005-0.2 mass% Si and the balance Cu with inevitable impurities is cast, is subjected to a hot-rolling, is subjected to an aging heat-treatment at 400-600°C for 30-600min, then is subjected to a cold-rolling under the prescribed condition, thereby obtaining the copper alloy for backing plate which is excellent in the oxidizing resistance and machineability in addition to good heat-conductivity, mechanical strength and heat-resistance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a copper alloy backing plate and a method for producing a copper alloy for a backing plate, and more particularly to producing a copper alloy backing plate and a copper alloy for a backing plate used for cooling a target material in a sputtering apparatus. Regarding the method.

  In recent years, the sputtering method has been used for producing various high-functional thin films. In the sputtering method, a glow discharge is generated by applying a high voltage between two electrodes in a low-pressure inert gas, and its constituent atoms are struck out from a target placed on the cathode by gas ion bombardment, and this is opposed to the substrate. This is one of the thin film formation techniques to be deposited on top.

  In sputtering, most of the energy input to the target is converted to heat in the surface area of the target. When the temperature of the target rises excessively due to this heat, the structure of the target material may change, and the desired film quality may not be obtained. For this reason, in the sputtering apparatus, a cooling member called a backing plate is arranged on the back surface of the target so that the temperature of the target does not rise excessively.

  As an example of the structure of the backing plate, a structure in which a groove is formed in a smooth plate and this is covered with a lid and joined to form an internal water channel is an example. The backing plate has a role of dissipating heat from the target (cooling the target), a role of fixing (holding) the target, and a role of a sputtering electrode. The target and the backing plate are often bonded (bonded) to the target by a low melting point brazing material such as an In alloy or Sn alloy.

  In order to cool the target efficiently, it is desirable that the thermal conductivity of the backing plate itself is good. If the thermal conductivity of the backing plate itself is low, the cooling effect is small, and it is difficult to avoid an increase in the temperature of the target material. Therefore, good thermal conductivity is required for the backing plate material, and oxygen-free copper has been mainly used (see, for example, Patent Document 1).

  As described above, the backing plate is required to have good thermal conductivity, while the backing plate has a high mechanical strength that can withstand stress caused by a temperature difference or a pressure difference between the front and back sides (for example, It is also required to have a high 0.2% proof stress and a high Young's modulus.

  If the mechanical strength of the backing plate is low, the backing plate may undergo large elastic deformation or plastic deformation during sputtering or repeated use. When large elastic deformation occurs, cracks may occur in the joint portion with the target material or the target material itself. Further, when plastic deformation occurs, it is necessary to replace the backing plate, which increases costs.

  In addition, it is desirable that the backing plate has good heat resistance in order to minimize the decrease in mechanical strength with time due to softening of the backing plate due to heating in the bonding process or the like.

From such a viewpoint, a copper alloy having good heat resistance is also used as a material for the backing plate as a conventional backing plate (see, for example, Patent Documents 2 to 4). Stainless steel has also been used from the viewpoint of high rigidity.
JP-A-10-110226 Japanese Patent No. 2555220 Japanese Patent Laid-Open No. 10-168532 JP-A-4-165039

  On the other hand, a process technology utilizing a sputtering method (that is, a backing plate application) has been developed as a basic technology in a wide range of fields such as semiconductor device manufacturing and flat display manufacturing. In recent years, in order to improve the productivity of the sputtering process and reduce the cost, the processing substrate has been steadily increasing in area.

  In particular, in the field of manufacturing flat panel displays (FPD) such as liquid crystal displays (LCD) and plasma display panels (PDP), in addition to increasing the screen size of the display panel itself to meet market needs, a single glass substrate Cost reduction is achieved by increasing the number of display panels (number of chamfers) that are simultaneously processed with (mother glass substrate).

The size of the mother glass substrate rapidly expanded from the fourth generation (730 × 920 mm ² ) around 2000, and the fifth generation (1100 × 1300 mm ² ), the sixth generation (1500 × 1800 mm ² ), and the seventh generation (1800). × 2100 mm ^2), finally is expected to eighth generation (2200 × 2600mm ^2), and the further the 9th generation (2600 × 3100mm ²⁾ to a larger area is gradually progress.

  Here, in order to improve the productivity (yield) of FPD and reduce the cost by using such a large area glass substrate, uniform and high-quality film formation over the entire surface of the large area glass substrate. Technology to realize the process is indispensable. Along with this, the size of the sputtering target and the backing plate is inevitably increased.

Examples of the size of the sputtering target include 1130 × 1200 mm ² for the fourth generation and 1430 × 1700 mm ² for the fifth generation. In addition, as an example of the size of the backing plate, there are 1170 × 1300 mm ² for the fourth generation, 1450 × 2050 mm ² for the fifth generation, etc., which are larger than the mother glass substrate and the sputtering target described above. It turns out that it is requested.

  As described above, in particular, in a sputtering apparatus for manufacturing an FPD, a large-area target material and a backing plate are used, and the absolute amount of generated heat increases, and at the same time, the deformation of the backing plate due to various stresses ( The absolute amount of displacement is likely to be large (for example, if the curvature of curvature is the same, the large area backing plate has a larger absolute value of warping deformation than the conventional small area backing plate). .

  Further, the use of a large-area target material and a backing plate has led to the emergence of phenomena that have not been noticeable in the past.

  For example, during storage of the backing plate or target bonding, gas components such as water vapor or oxygen in the atmosphere are adsorbed on the surface of the backing plate, penetrate into the surface layer, or oxidize the surface layer (hereinafter collectively referred to as the generic name). Simply expressed as “oxidation”), and the gas component dissociates from the backing plate during sputtering, which is a vacuum process, and adversely affects film quality (eg, homogeneity in large area films). To do.

  In particular, in a large area (large) backing plate having a side of 1 to 2 m or more, the problem is even more remarkable because the absolute surface area is large. For this reason, with the increase in size of the backing plate, a demand for characteristics that are difficult to oxidize and dissociate (hereinafter referred to as “oxidation resistance”) has emerged as a new issue.

  However, conventional backing plates, for example, oxygen-free copper backing plates, have low oxidation resistance, so that gas components such as water vapor and oxygen are likely to be dissociated during sputtering. There is a drawback that it takes time and effort. In particular, when the backing plate is enlarged, an effective baking process becomes even more difficult.

  Further, as described above, the manufacturing of the backing plate requires a cutting process for forming a water channel. However, oxygen-free copper and Cu-Fe-P-based copper alloys disclosed in Patent Document 2 are processed by cutting. There is a problem that it has poor properties and causes burrs and shortens the life of the cutting tool. Particularly in the case of a large backing plate, since the total length of the water channel to be formed is long, the problem becomes serious also in this respect.

  In other words, in addition to the properties conventionally desired for a backing plate (for example, thermal conductivity, mechanical strength, and heat resistance), a backing plate having particularly excellent oxidation resistance and good machinability It is desired.

  Accordingly, the object of the present invention is particularly in response to the demand for larger backing plates in addition to the properties (for example, thermal conductivity, mechanical strength, and heat resistance) conventionally desired for backing plates. An object of the present invention is to provide a copper alloy backing plate having both excellent resistance to oxidation and good machinability, and a method for producing a copper alloy for a backing plate.

  In order to achieve the above object, the present invention achieves Fe by 0.1 to 3.0% by mass, P by 0.001 to 0.1% by mass, Zn by 0.01 to 1.0% by mass, and Si by 0%. 0.005 to 0.2% by mass, the balance is Cu and inevitable impurities, the maximum crystal grain size is 0.15 mm or less, the thermal conductivity is 220 W / m · K or more, and the 0.2% proof stress is 400 MPa or more. A copper alloy backing plate manufactured using the above copper alloy is provided.

  Further, in order to achieve the above object, the present invention achieves Fe of 0.1 to 3.0% by mass, P of 0.001 to 0.1% by mass, Zn of 0.01 to 1.0% by mass, Si 0.005 to 0.2% by mass of Sn, 0.01 to 0.15% by mass of Sn or 0.01 to 0.2% by mass of Mg, the balance being made of Cu and inevitable impurities, A copper alloy backing plate manufactured using a copper alloy having a maximum of 0.15 mm or less, a thermal conductivity of 220 W / m · K or more, and a 0.2% proof stress of 400 MPa or more is provided.

  Further, in order to achieve the above object, the present invention achieves Fe of 0.1 to 3.0% by mass, P of 0.001 to 0.1% by mass, Zn of 0.01 to 1.0% by mass, Si Casting process for casting a copper alloy comprising Cu and unavoidable impurities, and the copper alloy is heated at a temperature of 800 ° C. or higher for 30 minutes or more and processed to be 50% or more. A hot rolling step in which hot rolling is performed at a rate, a heat treatment step in which heat treatment is performed at a temperature of 400 to 650 ° C. for 30 to 600 minutes after the hot rolling step, and a processing rate of 30% or more after the heat treatment step The manufacturing method of the copper alloy for backing plates including the cold rolling process which cold-rolls by this is provided.

  Further, in order to achieve the above object, the present invention achieves Fe of 0.1 to 3.0% by mass, P of 0.001 to 0.1% by mass, Zn of 0.01 to 1.0% by mass, Si A copper alloy containing 0.01 to 0.15% by mass of Sn or 0.01 to 0.2% by mass of Mg with the balance being Cu and inevitable impurities A casting process, a hot rolling process in which the copper alloy is heated at a temperature of 800 ° C. or higher for 30 minutes or more and hot rolled at a processing rate of 50% or more, and 400 to 650 ° C. after the hot rolling process. The manufacturing method of the copper alloy for backing plates including the heat treatment process which heat-processes for 30 to 600 minutes at the temperature, and the cold rolling process which cold-rolls with the process rate of 30% or more after the said heat treatment process is provided To do.

  According to the present invention, in addition to the properties conventionally desired for a backing plate (for example, thermal conductivity, mechanical strength, and heat resistance), in particular, the oxidation resistance corresponding to the demand for larger backing plate. It is possible to provide a copper alloy backing plate having both excellent properties and good machinability and a method for producing a copper alloy for a backing plate.

(Composition of copper alloy for backing plate)
The copper alloy for a backing plate in the first embodiment of the present invention has Fe of 0.1 to 3.0 mass%, P of 0.001 to 0.1 mass%, and Zn of 0.01 to 1. mass%. 0% by mass, containing 0.005 to 0.2% by mass of Si, the balance being made of Cu and inevitable impurities, the maximum crystal grain size is 0.15 mm or less, and the thermal conductivity is 220 W / m · K or more, 0 .2% proof stress is 400 MPa or more.

  The reason for adding the alloy components constituting the backing plate copper alloy of the present embodiment and the reason for limiting the component range will be described below.

  Fe has the effect of improving mechanical strength and heat resistance without significantly reducing thermal conductivity by being dispersed as a precipitate in Cu. If the amount is less than 0.1% by mass, the effect does not appear clearly, and if it exceeds 3.0% by mass, the decrease in the conductivity is increased, and coarse Fe crystallization is produced during casting, resulting in bonding properties. It will cause the decrease. Therefore, the content of Fe is set to 0.1 to 3.0% by mass. The recommended range is 2.0 to 2.3% by weight.

  P has an action of removing oxygen melted during melting. If the amount is less than 0.001% by mass, a sufficient effect cannot be obtained. If the amount exceeds 0.1% by mass, the deoxidation effect tends to be saturated, and a compound of P and Fe is present at the grain boundary during casting. It precipitates and causes grain boundary cracking during hot rolling. Therefore, the content of P is set to 0.001 to 0.1% by mass.

  Zn has the effect of improving bonding properties. If the amount is less than 0.01% by mass, a sufficient effect cannot be obtained, and if it exceeds 1.0% by mass, the decrease in conductivity becomes large. Therefore, the Zn content is set to 0.01 to 1.0 mass%. The recommended range is 0.05 to 0.15% by weight.

  Si forms an intermetallic compound with Fe to become solidification nuclei at the time of casting, and has the effect of improving the machinability by uniformly refining the metal structure. When the amount is less than 0.005% by mass, the sufficient effect cannot be obtained. When the amount exceeds 0.2% by mass, the effect of refining the metal structure is saturated and the decrease in conductivity becomes large. Therefore, Si content shall be 0.005-0.2 mass%. The recommended range is from 0.01 to 0.05% by weight.

  Further, the mechanism of improving the oxidation resistance of the copper alloy by adding Fe, P, Zn, Si has not been completely elucidated at present, but it is adsorbed on the surface of the backing plate, penetrates into the surface layer portion, or Gas components such as water vapor and oxygen in the atmosphere oxidized at the surface layer portion are considered to be selectively and firmly combined with additive components in Cu as compared with Cu, and this causes the gas from the backing plate during sputtering. It is considered that the effect of suppressing the dissociation of components (improves oxidation resistance) appears.

  The maximum crystal grain size in the copper alloy is preferably 0.15 mm or less. More preferably, it is 0.12 mm or less, More preferably, it is 0.1 mm or less. When the maximum crystal grain size is greater than 0.15 mm (for example, a cast structure remains), the metal structure tends to be non-uniform, leading to non-uniform mechanical strength (variation in crystal grain size). The mechanical strength of the part decreases). Therefore, the maximum crystal grain size is 0.15 mm or less.

[First Embodiment]
(Manufacturing method of copper alloy for backing plate)
FIG. 1 is a diagram showing a flow of a manufacturing process of a copper alloy for a backing plate according to the first embodiment. The copper alloy for backing plate of the present embodiment is first melted and mixed with ingredients to cast a copper alloy ingot containing the above components (step 1), and this copper alloy ingot is heated at a temperature of 800 ° C. or higher. After heating for more than a minute, hot-roll at a processing rate of 50% or more (step 2), after the hot rolling is completed, the material is water-cooled (step 3), and after water-cooling, the oxide scale of the material is removed by chamfering ( Step 4), the obtained hot-rolled material is subjected to an aging heat treatment at a temperature of 400 to 650 ° C. for 30 to 600 minutes to precipitate precipitate particles (Step 5), and at a processing rate of 30% or more. It is manufactured by cold rolling (step 6). In the casting step (step 1), oxygen-free copper having an oxygen concentration of 10 ppm or less is preferably used as the copper raw material. The processing rate is defined as “processing rate (%) = {1− (thickness after rolling / thickness before rolling)} × 100”.

  In the hot rolling step (step 2), if the temperature is less than 800 ° C. or the heating time is less than 30 minutes, a large amount of Fe particles and Fe and P processed products that remain in the cooling process during casting remain. When hot working is performed in such a state, the grain boundary precipitates deteriorate the hot workability and inhibit recrystallization, and intergranular cracking is likely to occur. Therefore, the recommended heating temperature is 900 to 950 ° C. On the other hand, when the processing rate is less than 50%, the metal structure is not uniformly recrystallized uniformly, and a part of the cast structure remains, and uniform characteristics cannot be obtained.

  In the water cooling step (step 3), the cooling start temperature (hot rolling end temperature) is preferably 600 ° C. or higher and the cooling rate is preferably 200 ° C./min or higher. This is because it becomes difficult to obtain high heat resistance and mechanical strength when Fe particles are precipitated and coarsened during the cooling process. Moreover, although hot rolling is a general method, you may substitute with hot forging.

  In the aging heat treatment step (step 5), the temperature is set to 400 to 650 ° C. When the temperature is lower than 400 ° C., Fe particles cannot be sufficiently precipitated, and when the temperature is 650 ° C. or higher, the Fe particles are coarsened. This is because the effect of improving heat resistance is small. Similarly, the aging heat treatment time is set to 30 to 600 minutes. Fe particles cannot be sufficiently precipitated in less than 30 minutes, and the Fe particles become coarse in 600 minutes or more, all of which have thermal conductivity, mechanical strength, This is because the effect of improving heat resistance is small. Recommended aging heat treatment conditions are 120-240 minutes at a temperature of 550-600 ° C.

  Further, it is desirable to perform cold rolling before aging heat treatment. This is in order to uniformly refine the Fe particles precipitated during the aging heat treatment by introducing lattice defects by cold rolling. The recommended processing rate is 30 to 80%.

  In the cold rolling step (step 6), the reason for setting the processing rate to 30% or more is that when the processing rate is less than 30%, the hardening due to processing is insufficient, and the mechanical strength necessary as a backing plate is obtained. It is because it is not possible. The recommended processing rate is 30 to 80%, more preferably 50 to 80%.

[Effect of the first embodiment]
According to the first embodiment, the following effects are obtained.
(1) By adding Fe, P, Zn and Si, a sputtering backing plate having both excellent oxidation resistance and good machinability can be obtained.
(2) In the aging heat treatment step (step 5), aging heat treatment is performed at a temperature of 400 to 650 ° C. for 30 to 600 minutes to precipitate Fe particles, and further cold rolling at a processing rate of 30% or more. Thus, a copper alloy for a backing plate having high thermal conductivity, mechanical strength, and heat resistance can be obtained. In addition, since the thermal conductivity can be 220 W / mK or more and the 0.2% proof stress can be 400 MPa or more, a backing plate for sputtering excellent in thermal conductivity and mechanical strength can be obtained.
(3) A sputtering backing plate having a long life (including repeated use such as rebonding) and high reliability (including film forming quality) can be obtained.

(Manufacturing of backing plate)
By using the copper alloy for a backing plate of the above embodiment, a backing plate used for a sputtering apparatus can be obtained by a usual manufacturing method. There is no restriction | limiting in the joining method with the cover which covers a water channel (groove), Any of electron beam welding, brazing, and friction stir welding may be sufficient. There is no limitation on the cooling medium for the backing plate. Further, the backing plate is not limited to the one made only of a copper alloy, and may include a reinforcing portion made of another metal such as stainless steel, for example.

[Second Embodiment]
(Composition of copper alloy for backing plate)
The copper alloy for a backing plate in the second embodiment of the present invention has Fe of 0.1 to 3.0 mass%, P of 0.001 to 0.1 mass%, and Zn of 0.01 to 1. mass%. 0% by mass, Si 0.005-0.2% by mass, Sn 0.01-0.15% by mass or Mg 0.01-0.2% by mass, the balance from Cu and inevitable impurities The maximum crystal grain size is 0.15 mm or less, the thermal conductivity is 220 W / m · K or more, and the 0.2% proof stress is 400 MPa or more. In addition, the manufacturing method of the copper alloy in 2nd Embodiment is the same as that of 1st Embodiment. Therefore, the description is omitted.

  The reason for adding the alloy components constituting the copper alloy for backing plate in the second embodiment and the reason for limiting the component range will be described below. Here, the reason for adding the Fe, P, Zn, and Si components and the reason for limiting the component range are the same as those in the first embodiment, and thus the description thereof is omitted.

  Sn dissolves in Cu and improves mechanical strength and heat resistance. If the amount is less than 0.01% by mass, a sufficient effect cannot be obtained, and if it exceeds 0.15% by mass, the decrease in the conductivity increases and the castability decreases. Therefore, Sn content shall be 0.01-0.15ass%. The recommended range is 0.02 to 0.1% by weight.

  Mg dissolves in Cu and improves mechanical strength and heat resistance. If the amount is less than 0.01% by mass, a sufficient effect cannot be obtained. If the amount exceeds 0.2% by mass, the decrease in conductivity is increased and the castability is decreased. Therefore, Sn content shall be 0.01-0.2 ass%. The recommended range is 0.02 to 0.1% by weight.

  Also, the mechanism of improving the oxidation resistance of copper alloys by containing Fe, P, Zn, Si, and Sn or Mg has not been completely elucidated at present, but it is adsorbed on the surface of the backing plate. Gas components such as water vapor and oxygen in the atmosphere that penetrate into the portion or oxidize in the surface layer portion are considered to be selectively and strongly bonded to the additive component in Cu as compared with Cu, thereby backing during sputtering. -It is thought that the effect which suppresses dissociation of this gas component from a plate (improves oxidation resistance) appears.

  The maximum crystal grain size in the copper alloy is preferably 0.15 mm or less. More preferably, it is 0.12 mm or less, More preferably, it is 0.1 mm or less. When the maximum crystal grain size is greater than 0.15 mm (for example, a cast structure remains), the metal structure tends to be non-uniform, leading to non-uniform mechanical strength (variation in crystal grain size). The mechanical strength of the part decreases). Therefore, the maximum crystal grain size is 0.15 mm or less.

[Effects of Second Embodiment]
According to the second embodiment, in addition to the addition of Fe, Zn, and Si shown in the first embodiment, Sn or Mg is added, so that it is more mechanical than the first embodiment. Strength and heat resistance can be improved.

[Other Embodiments]
In the above-described casting step (step 1), there is no restriction on the melting and casting method, and there is no restriction on the size of the material.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is not limited to these.

  First, according to the flow shown in FIG. 1, oxygen-free copper having an oxygen concentration of 10 ppm or less is used as a copper raw material, and copper alloys (alloys No. 1 to 6) having chemical compositions shown in Table 1 are melted in a medium frequency melting furnace. The components were adjusted, and an ingot having a thickness of 180 mm, a width of 500 mm, and a length of 4000 mm was cast. Subsequently, the ingot was heated at 900 ° C. for 3 hours and then hot rolled at a processing rate of about 80%. Further, after removing the oxide scale by chamfering, it was cold-rolled at a processing rate of about 15% to a thickness of 30 mm. This was heated at 575 ° C. for 3 hours in a non-oxidizing atmosphere and subjected to aging heat treatment, and then cold-rolled at a processing rate of 60% to a thickness of 12 mm.

  For the copper alloy specimens thus produced (Examples 1 to 3 and Comparative Examples 1 to 3), a test piece for measuring thermal conductivity and a test piece for evaluating mechanical properties (tensile test, hardness measurement, Softening test, milling), crystal grain size measurement specimen, and heat resistance evaluation specimen, respectively, thermal conductivity measurement, tensile test, hardness measurement, softening test, face shape evaluation in milling, crystal Particle size measurement and heat resistance evaluation were performed. Comparative Example 1 is a test material made of oxygen-free copper (JIS H3300 C1020). The evaluation results are shown in Table 1.

  For the thermal conductivity measurement, a laser flash method (manufactured by ULVAC-RIKO Inc., model: TC-7000) was used. The tensile test was performed based on JIS Z2241, using a universal testing machine (manufactured by Shimadzu Corporation, model: AG-I). The heat resistance evaluation was performed by immersing the test piece in a salt bath set at a predetermined temperature (100 to 500 ° C. at 50 ° C. intervals) for 5 minutes (salt bath heat treatment), so that the Vickers hardness (Hv) was 80% before heating. The softening temperature was evaluated. The Vickers hardness was measured using a Vickers hardness meter (manufactured by Akashi Co., Ltd., model: MVK-G2). For the face shape evaluation in milling, milling was performed under the same conditions using an NC lathe (Okuma Corporation, model: LS30-N), and the face shape was observed and evaluated visually (sketch). The crystal grain size was measured using an optical microscope (manufactured by Olympus Corporation, model: PMG3) based on the cutting method in JIS H 0501. In addition, as a salt of salt bath heat treatment, the product name: Super Salt M-2 made by Nisshinka Thermal Industrial Co., Ltd. was used.

  In addition, the test pieces for evaluating oxidation resistance were obtained by cutting a plurality of plate materials (vertical × horizontal = 4 cm × 4 cm) of Examples 1 to 3 and Comparative Examples 1 to 3, and overlapping the same material between glass plates, A clip was prepared from the outside of the plate. The evaluation of oxidation resistance was carried out by holding the test piece prepared as an accelerated test in a constant temperature and humidity chamber (temperature = 60 ° C., relative humidity = 90%) for 40 hours, and then measuring the thickness of the oxide film formed on the superimposed surface. Measured and calculated by the cathode reduction method.

The measurement conditions for the cathode reduction method were set as follows.
Electrolysis conditions: KCl aqueous solution [0.1 mol / L], nitrogen gas saturated electrolysis area: 1 cm ²
Current density: 50 μA / cm ²
Reference electrode: Ag / AgCl
Counter electrode: Pt

The oxide film thickness was calculated from the amount of electricity required for reduction of the oxide film and the theoretical density of the oxide film based on Faraday's law according to the following document.
(Reference) M. Seo et al .: Cathodic reduction of the duplex oxide films formed on
copper in air with high relative humidity at 60 ℃, Corrosion Science, Volume 47
(2005) p.2079-2090.

  Moreover, as shown to Fig.2 (a)-(c), the face shape by milling was evaluated. Here, Fig.2 (a) is a face shape of Examples 1-3, FIG.2 (b) and (c) are figures which show the face shape of a comparative example.

  As a result, the alloy No. Nos. 1 to 3 are alloy Nos. According to Comparative Example 4 whose hardness and softening temperature are oxygen-free copper. A value higher than 4 was obtained. Furthermore, the face shape of Examples 1 to 3 is a fragmented face 21 as shown in FIG. 2 (a), and the alloy No. of the curled face 23 shown in FIG. This is better than 4, and the machinability is improved.

  Further, Alloy No. 1 according to Example 1 was used. 1 is an alloy No. 1 of Comparative Example 2 to which Si was not added. 5, the thermal conductivity, 0.2% proof stress, hardness, and softening temperature are the same, but the shape of the facets is good (subdivided) and the machinability is improved.

  In addition, Alloy No. The shape of the facet 5 becomes a long facet 22 shown in FIG. 2 (b), and the machinability is lowered. Furthermore, alloy No. 3 of Comparative Example 3 having a large Fe content. No. 6 has a thermal conductivity of 180 (W / m · K), which is the lowest among the examples and comparative examples.

  In addition, from the oxidation resistance evaluation results, Examples 1 to 3 according to the present invention have an oxide film thickness of 20 to 25 nm, which is sufficiently smaller than Comparative Examples 1 to 3, and has excellent oxidation resistance. I understand that. Therefore, it can be said that Examples 1-3, especially Example 1 are suitable as a copper alloy for large backing plates for sputtering. On the other hand, in Comparative Examples 1-3, it turns out that the thickness of the formed oxide film is as large as 35 nm or more in the oxidation resistance evaluation test.

  Next, Alloy No. 1 according to Example 1 shown in Table 1 was used. 1, a plurality of test materials 1 to 8 (Examples 11 to 14 and Comparative Examples 11 to 14) according to the manufacturing conditions shown in Table 2 were manufactured, and the same evaluation was performed.

  As is clear from Table 2, the test material No. In No. 5, since the hot rolling processing rate was as low as 30%, a part of the cast structure remained, and the maximum crystal grain size was larger than 0.15 mm. Sample No. according to Comparative Example 12 In No. 6, since the aging heat treatment temperature was as low as 350 ° C., satisfactory characteristics in thermal conductivity, hardness, and heat resistance could not be obtained. In addition, the test material No. In No. 7, since the aging heat treatment temperature was as high as 700 ° C., satisfactory characteristics were not obtained in terms of thermal conductivity, hardness, and heat resistance. Furthermore, the test material No. In No. 8, the cold rolling ratio was as low as 10%, so the hardness was low.

  On the other hand, the test material No. by Example 11-14. As for 1-4, the favorable result is obtained about thermal conductivity, hardness, and heat resistance.

FIG. 1 is a manufacturing process diagram of a copper alloy for a backing plate according to the first embodiment of the present invention. FIG. 2 is a face shape diagram by milling.

Explanation of symbols

21, 22, 23 facet

Claims (4)

  Fe 0.1-3.0% by mass, P 0.001-0.1% by mass, Zn 0.01-1.0% by mass, Si 0.005-0.2% by mass, the balance Is made of copper and inevitable impurities, the maximum grain size is 0.15 mm or less, the thermal conductivity is 220 W / m · K or more, and the 0.2% proof stress is 400 MPa or more. Features a copper alloy backing plate.   While containing 0.1-3.0 mass% Fe, 0.001-0.1 mass% P, 0.01-1.0 mass% Zn, 0.005-0.2 mass% Si, It contains 0.01 to 0.15% by mass of Sn or 0.01 to 0.2% by mass of Mg, the balance is made of Cu and inevitable impurities, the maximum crystal grain size is 0.15 mm or less, and the thermal conductivity is A copper alloy backing plate manufactured using a copper alloy of 220 W / m · K or more and 0.2% proof stress of 400 MPa or more. Fe 0.1-3.0% by mass, P 0.001-0.1% by mass, Zn 0.01-1.0% by mass, Si 0.005-0.2% by mass, the balance A casting process of casting a copper alloy comprising Cu and inevitable impurities;
A hot rolling step in which the copper alloy is heated at a temperature of 800 ° C. or higher for 30 minutes or more and hot rolled at a processing rate of 50% or more;
A heat treatment step of performing a heat treatment for 30 to 600 minutes at a temperature of 400 to 650 ° C. after the hot rolling step;
And a cold rolling step of performing cold rolling at a processing rate of 30% or more after the heat treatment step. While containing 0.1-3.0 mass% Fe, 0.001-0.1 mass% P, 0.01-1.0 mass% Zn, 0.005-0.2 mass% Si, A casting step of casting a copper alloy containing 0.01 to 0.15% by mass of Sn or 0.01 to 0.2% by mass of Mg, with the balance being Cu and inevitable impurities;
A hot rolling step in which the copper alloy is heated at a temperature of 800 ° C. or higher for 30 minutes or more and hot rolled at a processing rate of 50% or more;
A heat treatment step of performing a heat treatment for 30 to 600 minutes at a temperature of 400 to 650 ° C. after the hot rolling step;
And a cold rolling step of performing cold rolling at a processing rate of 30% or more after the heat treatment step.

Images