KR20120125248A - Pure copper plate production method, and pure copper plate - Google Patents

Abstract

Provided are a method for producing a pure copper plate which has a fine crystal structure, has a moderate hardness, and gives a high specific grain boundary length ratio, and a pure copper plate such as a sputtering target or a plating anode produced by the method. . Pure copper ingots with a purity of 99.96 wt% or more were 550? It heated at 800 degreeC, rolling rate was 80% or more, and rolling completion temperature was 500? After performing the hot rolling process which is 700 degreeC, until it becomes the temperature of 200 degrees C or less from the said rolling completion temperature, it is 200? It was quenched at a cooling rate of 1000 deg. C / min, and thereafter, 5? Cold rolling and annealing are performed at a rolling rate of 24%.

Description

Pure copper plate manufacturing method and pure copper plate {PURE COPPER PLATE PRODUCTION METHOD, AND PURE COPPER PLATE}

The present invention provides a method for producing a pure copper plate having good quality, in particular having a fine crystal structure, having a moderate hardness, and providing a high special grain boundary length ratio by forming a twin structure by partial recrystallization. The present invention relates to a method for producing a pure copper plate, and a pure copper plate of a material such as a sputtering target or a plating anode produced by the method.

This application claims priority based on Japanese Patent Application No. 2010-26453 for which it applied on February 9, 2010, and uses the content here.

Pure copper plate is usually produced by hot rolling or hot forging of an ingot of pure copper, followed by cold rolling or cold forging, followed by heat treatment for strain removal or recrystallization. Such a pure copper plate is processed and used to a desired shape by saw cutting, cutting, embossing, cold forging, etc., but in order to reduce the traces at the time of processing, a small crystal grain size is calculated | required.

Moreover, the pure copper plate manufactured by the method mentioned above is used as a sputtering target for the wiring material of a semiconductor element in recent years. Al has been used as a wiring material of a semiconductor element, but with the recent miniaturization of wiring, copper wiring with a lower resistance (about 1.7 µΩ? Cm in specific resistance) has been put into practical use. As a formation process of this copper wiring, after forming a diffusion barrier layer, such as Ta / TaN, in the recessed part of a contact hole or a wiring groove, copper is often electroplated, and in order to perform this electroplating, As a seed layer, sputter film-forming of pure copper is performed.

Usually, it is 5 N (purity of 99.999% or more) by the wet or dry high-purification process using the electrocopper of about 4N (purity 99.99% or more: gas component removal) as a rough metal. 6N (purity 99.9999% or more) of high purity copper is manufactured, this is made into a pure copper plate by the method mentioned above, and it is used as a sputtering target after processing to a desired shape again. In order to produce a sputter film with a low electrical resistance, it is necessary to suppress the impurity content in the sputtering target to a fixed value or less, and to lower the element added in order to alloy, and to obtain uniformity of the sputter film thickness, It is necessary to suppress the dispersion | variation in the crystal grain diameter and crystal orientation of a sputtering target.

As a conventional method for industrially manufacturing such a sputtering pure copper target, Patent Document 1 hot-processes an ingot of pure copper having a purity of 99.995 wt% or more, and then performs annealing at a temperature of 900 ° C. or lower, Subsequently, after cold rolling is carried out at a rolling rate of 40% or more, recrystallization annealing at a temperature of 500 ° C. or lower, the copper target for sputtering having a substantially recrystallized structure, an average crystal grain size of 80 microns or less, and a Vickers hardness of 100 or less A method of obtaining is disclosed.

Moreover, after performing hot processing of 50% or more of high-purity copper ingots of 5N or more high processing rate, such as hot forging and hot rolling, patent document 2 further cold-processes 30% or more of processing rates, such as cold rolling and cold forging. And 350? 500 ° C., 1? By performing heat treatment for 2 hours, Na and K contents are each 0.1 ppm or less, Fe, Ni, Cr, Al, Ca, and Mg contents are 1 ppm or less, respectively, carbon and oxygen contents are 5 ppm or less, U and Th content, respectively. 1 ppb or less each, the content of copper which removed the gas component is 99.999% or more, the average particle diameter on a sputter surface is 250 micrometers or less, and the variation of an average particle diameter is within ± 20%, and X-ray-diffraction intensity ratio I ( A method of obtaining a sputtering copper target having 111) / I (200) of 2.4 or more in the sputtering surface and a deviation thereof within ± 20% is disclosed.

In addition, in Patent Document 3, Al obtained by removing a surface layer of high purity copper having a purity of 6N or higher and an additional element from a hot forging, a hot rolling, a cold rolling, and a heat treatment step is 0.5? It contains 4.0 wt%, Si is 0.5 wtppm or less, and copper alloy sputtering target, Sn is 0.5? Copper alloy sputtering target containing 4.0 wt% and Mn of 0.5 wtppm or less, and 1.0 wtppm or less in total containing 1 or 2 or more selected from Sb, Zr, Ti, Cr, Ag, Au, Cd, In, As. A copper alloy sputtering target is disclosed. In particular, in the Example, the surface layer of the manufactured ingot was removed to be φ160 mm × thickness 60 mm, and then hot forged at 400 ° C. to φ200 mm, and then hot rolled at 400 ° C. to φ270 mm × thickness 20 mm It is rolled to and further cold-rolled, and it rolls to φ360 mm x thickness 10 mm, and after heat-processing at 500 degreeC for 1 hour, there exists a description which makes the whole target quench and makes it a target material.

As represented by such a method for producing a sputtering copper target, in the conventional method for producing a pure copper plate, in order to obtain a homogeneous and stable recrystallized structure, the cold copper ingot is subjected to hot forging or cold rolling after hot forging or hot rolling. Rolling is performed and heat treatment is further performed.

Japanese Patent Application Laid-Open No. 11-158614 Japanese Patent Application Laid-Open No. 10-330923 Japanese Unexamined Patent Publication No. 2009-114539

However, in the conventional method of industrially producing pure copper plate having a large homogeneous and stable crystal structure, it is necessary to perform additional cold forging, cold rolling or heat treatment after hot forging or hot rolling to pure copper ingot. However, when the pure copper plate is used for a sputtering target, a plating anode, or a heat dissipation substrate, the sputtering target suppresses abnormal discharge in the sputter for a long time, improves in-plane dissolution homogeneity in the plating anode, and heat-resistant fatigue characteristics in the heat dissipation substrate. With respect to such characteristics, it has become difficult to respond only by miniaturization.

This invention is made | formed in view of such a situation, Especially, in manufacture of a sputtering target material and an anode material for plating, the rolling rate in cold rolling is made into the rolling plate which consists of hot-rolled pure copper at 5? It is intended to provide a pure copper plate suitable for sputtering targets and plating anodes by setting it to 24% and having a fine crystal structure by further annealing and forming a twin structure by partial recrystallization, thereby providing a sputtering target or an anode for plating. It is done.

As a result of earnest examination, the inventors of the present invention hot rolled ingots of pure copper under certain conditions in order to suppress the growth of crystal grains, and cold rolling and heat treatment after quenching under constant conditions in order to stop grain growth. When the length ratio of the special grain boundary measured by the EBSD method was 25% or more, it was found that the pure copper plate which suppressed abnormal discharge during sputtering and suppressed generation of insoluble slime during plating could be produced.

The manufacturing method of the pure copper plate of this invention is a 550 degreeC ingot of pure copper whose purity is 99.96 wt% or more. It heated at 800 degreeC, the total rolling ratio is 80% or more, and the temperature at the end of rolling is 500? After performing the hot rolling process which is 700 degreeC, until it becomes the temperature of 200 degrees C or less from the temperature at the end of the said rolling, it is 200? It was quenched at a cooling rate of 1000 deg. C / min, and thereafter, 5? It is characterized by cold rolling and annealing at a rolling rate of 24%.

In order to obtain fine crystal grains, it is effective to quench after applying a large energy by hot rolling, but in that case, the hot rolling end temperature is 500? It is important to suppress it at 700 degreeC. When hot rolling end temperature exceeds 700 degreeC, crystal grain will become large rapidly and it will be difficult to obtain fine crystal grain even if it quenchs after that. Moreover, even if hot rolling end temperature is less than 500 degreeC, the effect of refinement | miniaturization of a crystal grain size is saturated, and even if it lowers more than that, it does not contribute to refinement | miniaturization. Moreover, when rolling temperature is low, excessive energy is needed in order to obtain desired total rolling ratio, and the processing is difficult. And this hot rolling finish temperature is 500? In order to set it as 700 degreeC, the starting temperature of hot rolling shall be 550? It was 800 degreeC.

Moreover, it is preferable to set it as 80% or more as the total rolling ratio by this hot rolling, The big energy which made the total rolling ratio 80% or more suppresses increase of crystal grain, and can make the deviation small. . When the total rolling rate is less than 80%, the crystal grains tend to be large, and the deviation increases.

And after completion | finish of such hot rolling, until it becomes the temperature of 200 degrees C or less, it is 200? It is quenched at a cooling rate of 1000 ° C./min. If the cooling rate is less than 200 ° C / min, the effect of suppressing the growth of crystal grains is insufficient, and even if it exceeds 1000 ° C / min, it does not contribute to further miniaturization. More preferred cooling rate is 300? It is the range of 600 degreeC / min.

Cooling to a temperature of 200 ° C. or lower at such a cooling rate stops the growth of the crystal grains, thereby obtaining fine crystal grains. If quenching is stopped at a temperature exceeding 200 ° C, there is a fear that the crystal grains will gradually grow by standing in the high temperature state after that.

And after this quench, 5? By performing cold rolling and annealing at a rolling rate of 24%, the crystal grain size becomes fine, and a special grain boundary ratio can be imparted by forming a twin structure by partial recrystallization.

Moreover, the pure copper plate manufactured by the manufacturing method of this invention is the ratio of the total special grain boundary length L (sigma) of a special grain boundary with respect to the total grain boundary length (L) of the crystal grain boundary measured by EBSD method (special grain boundary length ratio, Lσ). / L) is 25% or more.

Moreover, the average crystal grain diameter measured by EBSD method is 10? 120 µm, Vickers hardness is 40? 90 is more preferable.

In particular, when the above-mentioned special grain boundary length ratio is 25% or more, the consistency of crystal grain boundaries is improved, and various characteristics such as suppression of abnormal discharge in the sputter of the sputtering target and improvement of in-plane dissolution homogeneity of the plating anode are improved.

It is preferable to use the pure copper plate of this invention for a sputtering target or a plating anode.

As described above, since the pure copper plate of the present invention has a fine grain size and a special grain boundary length ratio of 25% or more, when used as a sputtering target, abnormal discharge can be suppressed over a long time, and used as an anode for plating. In this case, in-plane dissolution homogeneity can be improved to suppress generation of insoluble slime.

Advantageous Effects of Invention According to the present invention, a fine grain size and a special grain boundary length ratio of 25% or more improve the target and the in-plane dissolution homogeneity which can suppress abnormal discharge over a long time, thereby suppressing the generation of insoluble slime. An anode can be provided.

BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a micrograph of a burr generated when the surface of a pure copper plate is cut.

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described.

The pure copper plate of this embodiment is oxygen free copper whose copper purity is 99.96 wt% or more, or oxygen free copper for electron tubes which is 99.99 wt% or more.

The average grain size of the rolled sheet of the present invention is 10? 120 µm and Vickers hardness of 40? It is 90, and the special grain boundary length ratio measured by the EBSD method is 25% or more.

When large crystal grains whose crystal grain diameter exceeds 200 micrometers mix, it is easy to produce a fine grain on the surface in cutting. As shown in FIG. 1, this grind | substrate is represented by the code | symbol C in the direction orthogonal to a cutting direction in the cutting trace W which arises in the cutting direction (direction shown by arrow A), when cutting a raw material with a price etc. As described above, fine unevenness occurs in the form of stripes. If this rubs out, it will damage the appearance of the product.

In addition, it is not practical to set the average grain size to less than 10 µm, resulting in an increase in manufacturing cost.

Moreover, by forming a twin structure by partial recrystallization and making a special grain boundary length ratio 25% or more, the consistency of a grain boundary improves, and it is effective for uses, such as a sputtering target and a plating anode.

The crystal grain boundary is defined as a boundary between the crystals when the orientation between two neighboring crystals is 15 degrees or more as a result of two-dimensional cross-sectional observation. Special grain boundaries are crystal grain boundaries (corresponding to 3??? 29 with? Values defined crystallographically based on the CSL theory (Kronberg et. Al .: Trans. Met. Soc. AIME, 185, 501 (1949)). Grain boundary), where the intrinsic corresponding site lattice orientation defect (Dq) at the grain boundary satisfies Dq≤15 ° / Σ ^1/2 (DG Brandon: Acta. Metallurgica. Vol. 14, p 1479, 1966). It is defined as

Among all the grain boundaries, if the length ratio of this special grain boundary is high, the conformity of the grain boundaries is improved, and characteristics such as a sputtering target, a plating anode, or a heat dissipation substrate, which are widely used as pure copper plates, can be improved.

That is, in the sputtering target, there is a correlation between the abnormal discharge characteristics and the crystal structure at the time of sputtering, and the purity of the material is reduced, that is, the amount of impurities contained (JP-A-2002-129313) and the homogeneity of the particle size ( WO 03/046250), control of crystal orientation of a structure (Japanese Patent Laid-Open No. H10-330923) and the like disclose means for suppressing abnormal discharge in sputtering characteristics. However, in recent years, further improvement of the sputter rate is required to improve productivity, so that the sputter voltage is in a direction of becoming high voltage. When the sputtering voltage is improved, an abnormal discharge during sputtering is more likely to occur. Therefore, the conventional structure control method alone is insufficient for the abnormal discharge suppression effect, and new structure control has been required.

In addition, the copper anode material for plating is particularly used for through-hole plating of printed wiring boards, and at the time of melting of the anode, non-uniformity of current density distribution occurs, resulting in local conduction failure, resulting in insoluble slime, resulting in poor plating. However, it may lead to the fall of production efficiency. As a countermeasure, it is effective to increase in-plane dissolution homogeneity at the dissolution surface of the anode, and measures are taken by miniaturization of crystal grains. However, in general, grain boundaries are easier to dissolve compared to the grains, and even if the in-plane dissolution homogeneity of the anode is improved by refining, selective dissolution of the grain boundaries is inevitable, and it has been found that there is a limit to the refinement effect. Therefore, while it is thought that suppressing the solubility of the grain boundary itself is effective for the generation of the slime, no consideration has been made in view of such a viewpoint.

Moreover, in a heat radiation board | substrate, since expansion and contraction are repeated at the time of use, it is important to have uniform deformation | transformation characteristic and excellent fatigue characteristic. In recent years, orthogonal inverter circuits are indispensable in hybrid cars, solar cells, and the like, which are being spread due to energy saving and low CO, and are made of pure copper or low alloy as a heat dissipation substrate for dissipating heat generated during conversion. Copper plates are used. In these applications, a large current is progressing due to the enlargement of the system, and the heat burden applied to the heat dissipation substrate is in an increasing direction. The heat radiation substrate is required to have thermal fatigue resistance in the long term because thermal expansion / contraction is repeated during use. Although homogeneity of a structure is important about heat-resistant fatigue characteristic, improvement of the fatigue characteristic accompanying the said large currentization is difficult only by improving the uniformity of the conventional structure.

These problems can be solved by making the average crystal grain size fine and making the ratio of the length of the special grain boundary of a grain boundary into 25% or more. That is, since the sputtering target is sputtered homogeneously throughout the sputter surface, the step of the grain boundary which causes abnormal discharge hardly occurs, and as a result, the number of abnormal discharges is reduced. As for the plating anode, it was found that the special grain boundary had properties that were closer to dissolution characteristics in the mouth than the general grain boundary, and in-plane dissolution homogeneity at the time of the anode dissolution was significantly improved by using a copper plate with a high specific grain boundary ratio. Since it is kept smooth, generation | occurrence | production of insoluble slime is suppressed and the quality of the plating film formed is improved. Moreover, in a heat radiating board | substrate, it shows uniform deformation characteristic, metal fatigue does not produce easily also by repetition of thermal expansion and thermal contraction, and heat-resistant fatigue characteristic improves.

Thus, the pure copper plate of this invention makes the suppression of abnormal discharge in a sputtering target, suppression of insoluble slime in a plating anode, and heat-resistant fatigue in a heat radiating board | substrate by making the length ratio of a special grain boundary into 25% or more. Effects such as improvement in characteristics can be seen, and are preferable for a sputtering target, a plating anode, a heat radiation substrate, and the like.

Next, the method of manufacturing such pure copper board is demonstrated.

First, the ingot of pure copper 550 ℃? It heats at 800 degreeC, and makes the gap between rolling rolls small gradually, rolling it to predetermined thickness, making it reciprocate between multiple rolling rolls several times. The rolling ratio by this multiple times of rolling becomes 80% or more, and the temperature at the end of rolling is 500? It becomes 700 degreeC. Thereafter, the temperature is 200? It is quenched at a cooling rate of 1000 ° C./min. After that, 5? Cold rolling at a rolling rate of 24%, and at 250? 30 minutes at 600 ℃? Annealed by heating for 2 hours.

In the process for producing pure copper plate, hot rolling is performed in a process of hot rolling ⇒ cooling ⇒ cold rolling ⇒ heat treatment. It is processed at a high temperature of 900 ° C. When hot rolling in such a high temperature state, crystal grains coarsen, and even if it is quenched, an average crystal grain size cannot be refined to 80 micrometers or less.

In the manufacturing method of this embodiment, the start temperature of hot rolling is 550? 800 ℃, end temperature is 500? It was made into the comparatively low temperature state of 700 degreeC. When the end temperature of hot rolling exceeds 700 degreeC, crystal grains become large rapidly and it is difficult to obtain fine crystal grains even if it quenchs after that. Moreover, even if hot rolling end temperature is less than 500 degreeC, the effect of refinement | miniaturization of a crystal grain size is saturated, and even if it lowers below, it does not contribute to refinement | miniaturization. Moreover, when rolling temperature is low, excessive energy is needed in order to obtain desired total rolling ratio, and the processing is difficult. Therefore, the rolling end temperature is 500? It was 700 degreeC. And the end temperature of this hot rolling is 500? In order to set it as 700 degreeC, the starting temperature of hot rolling shall be 550? It was 800 degreeC.

Moreover, as a rolling rate by this hot rolling, it is preferable to set it as 80% or more. By making a rolling rate 80% or more, coarsening of a crystal grain size can be suppressed and the dispersion | variation can be made small. It is preferable to make a rolling rate into 80% or more from such a viewpoint. When the rolling ratio is less than 80%, the crystal grains tend to be large, and the variation is large. Moreover, it is more preferable to make the rolling reduction rate per pass into 25% or more about the rolling of the last stage among the several times of rolling performed in order to achieve the said rolling rate. By increasing the reduction ratio at 25% or more at the end of the hot rolling, mixing of large crystal grains is prevented and fine crystal grains can be obtained as a whole. One pass of rolling of the last stage with this rolling reduction more than 25%? You may do it several times. This rolling reduction rate per 1 pass means the reduction rate of the plate | board thickness of the base material after rolling roll passage with respect to the plate | board thickness of the base material before passing a rolling roll (or between the rolling rolls of this pass with respect to the gap between the rolling rolls at the time of the last pass | pass). Gap reduction rate), and the total rolling rate is a reduction rate of the sheet thickness of the base material after the end of rolling with respect to the base material before rolling. In other words, when the base metal plate thickness prior to passing through the rolling rolls to t _0, rolling rolls the plate thickness of the base material after passing through a ₁ t, γ rolling reduction per pass (%) _{is, γ = ((t 0 -t} 1 / t ₀ ) × 100 (%).

And after completion | finish of such hot rolling, until it becomes the temperature of 200 degrees C or less, it is 200? It is quenched by water cooling at a cooling rate of 1000 ° C / min. If the cooling rate is less than 200 ° C / min, the effect of suppressing the growth of crystal grains is insufficient, and even if it exceeds 1000 ° C / min, it does not contribute to further miniaturization.

Cooling to a temperature of 200 ° C. or lower at such a cooling rate stops the growth of the crystal grains, thereby obtaining fine crystal grains. If quenching is stopped at a temperature exceeding 200 ° C, there is a fear that the crystal grains will gradually grow by standing in the high temperature state after that.

Cold rolling is then performed in order to improve hardness, strength, improve flatness, obtain a good surface state, and then heat treatment thereafter to increase the length ratio of the special grain boundary of the grain boundary to 25% or more. 5? It becomes the rolling rate of 24%. If the rolling ratio is less than 5%, it is difficult to obtain a desired special grain boundary ratio, while no more effect can be seen even if it exceeds 24%.

The annealing treatment is performed in order to form a twin structure by partial recrystallization using the strain energy introduced by cold rolling to improve the special grain boundary length ratio. Annealing temperature is 250? 600 degreeC is preferable, and it is 30? In the heating atmosphere. 120 minutes is sufficient.

Example

Next, an embodiment of the present invention will be described.

As a rolled material, the casting ingot of oxygen-free copper (purity 99.99 wt% or more) for an electron tube was used. The raw material dimensions before rolling were made into width 650 mm x length 900 mm x thickness 290 mm, and the pure copper board was produced combining multiple conditions as shown in Table 1 after hot rolling. In addition, the measurement of temperature was performed by measuring the surface temperature of a rolling plate using a radiation thermometer.

Next, with respect to the pure copper plate of Table 1, the average crystal grain size, the special grain boundary length ratio, the Vickers hardness, the number of abnormal discharges in the sputtering when used as a sputtering target, and the insoluble slime when used as an anode for plating The amount of generated was measured.

<Average grain size, special grain length ratio>

Each sample was subjected to mechanical polishing using water resistant abrasive paper and diamond abrasive grains, and then finished polishing was performed using a colloidal silica solution.

And crystal grain boundary and special grain boundary are identified by EBSD measuring apparatus (S4300-SE by HITACHI company, OIM Data Collection by EDAX / TSL company) and analysis software (OIM Data Analysis Ver. 5.2 by EDAX / TSL company), By calculating the length, the average grain size and the special grain boundary length ratio were analyzed.

First, an electron beam is irradiated to individual measurement points (pixels) within the measurement range of a sample surface using a scanning electron microscope, and the orientation difference between adjacent measurement points is 15 degrees or more by orientation analysis by backscattered electron beam diffraction. The crystal grain boundary was made between the measurement points.

The measurement of the average crystal grain size (counted as paired crystal grains) calculates the number of crystal grains in the observation area from the obtained grain boundaries, divides the area area by the number of crystal grains, calculates the crystal grain area, and converts it to the average to obtain an average. It was set as the crystal grain diameter (diameter).

In addition, the total grain boundary length L of the crystal grain boundaries in the measurement range is measured, and the position of the crystal grain boundaries where the interface of adjacent crystal grains constitutes the special grain boundary, and the total special grain boundary length of the special grain boundary ( Lσ) and the grain boundary length ratio (Lσ / L) of the total grain boundary length L of the measured grain boundary were calculated | required, and it was set as the special grain boundary length ratio.

<Vickers hardness>

Vickers hardness was measured by the method prescribed | regulated to JIS (Z2244) about the longitudinal cross section (surface seen from the T. D. direction) along a rolling direction (R. D. direction).

<Sputter abnormal discharge count>

The target portion 152 ㎜ diameter from each sample, to produce a one-piece target, including a portion of the backing plate such that the thickness 8 ㎜ mounted in a sputtering apparatus, and the vacuum pressure in the chamber below the reaching 1 × 10 ^-5 ㎩, high purity as a sputtering gas Sputtering gas pressure was 0.3 kPa using Ar, and 8 hours of continuous sputter | spatters were performed on the conditions of 1 kPa of sputter outputs by the direct current (DC) power supply. Moreover, the total abnormal discharge count was counted using the arcing counter attached to a power supply.

<Anode slime generation amount>

 The copper plate cut out in the disk shape of diameter 270mm was fixed to the electrode holder (approximately 530 cm <2> of execution electrode area), and it is set as an anode electrode, copper plating is performed on the following conditions, using the silicon wafer of diameter 200mm as a cathode, and plating starts. Insoluble slime generated when the wafer was processed from the fifth to the fifth sheet was collected, and the amount of slime was measured. In addition, the slime generation amount was calculated | required by the weight measurement after drying after slime was collected.

Plating solution: 70 g / l copper pyrolate, 300 g / l potassium pyrolate, 15 g / l potassium nitrate was added to ion-exchanged water, and adjusted to pH 8.5 with ammonia water,

Plating conditions: stirring by air stirring and cathode rocking at a liquid temperature of 50 ℃,

Cathode current density: 2 A / dm ² ,

Plating time: 1 hour / sheet.

<Flame state>

Each sample was made into a flat plate of 100 × 2000 mm, and the surface was cut by a price plate at a cutting depth of 0.2 mm and a cutting speed of 5000 m / min using a bite of a carbide blade. It was examined how many scratch marks were 100 µm or more in length in the µm square visual field.

These results are shown in Table 2.

As is apparent from Table 2, all the pure copper plates produced by the production method of this example had an average grain size of 10? 120 µm, and the hardness is 40? It is in the range of 90 HPa, and the special grain boundary length ratio is 25% or more. On the other hand, in the pure copper plate of a comparative example, the average grain size, hardness, or special grain boundary length ratio are out of range. As a result, it turns out that the number of abnormal discharges in the sputtering target of an Example is very low, and the generation amount of insoluble anode slime in dissolution characteristic evaluation when used as a plating anode is also very low. On the other hand, in the comparative example, it was also observed that the number of abnormal discharges was higher, the amount of anode slime was also increased, and rubbing occurred in the surface state after machining in the comparative example.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this description, It can change suitably in the range which does not deviate from the technical idea of the invention.

Industrial availability

The pure copper plate of this invention is applicable to the target for sputtering, the backing plate for targets, In addition, a plating anode, a metal mold | die, a discharge electrode, a heat sink, a heat sink, a mold, a water cooling plate, an electrode, an electric terminal, a bus It can also be applied to bars, gaskets, flanges and printing plates.

W: cutting mark
C: Mark marks

Claims (6)

550? Ingots of pure copper with a purity of 99.96 wt% or more? It heated at 800 degreeC, the rolling ratio of hot rolling is 80% or more, and rolling end temperature is 500? After performing the hot-pressing process which is 700 degreeC, until it becomes the temperature of 200 degrees C or less from the said rolling completion temperature, it is 200? It quenched at the cooling rate of 1000 degree-C / min, and after that, 5? It cold-rolls and anneales at the rolling ratio of 24%, The manufacturing method of the pure copper plate characterized by the above-mentioned. The pure copper plate manufactured by the manufacturing method of Claim 1 whose ratio (Lσ / L) of the total special grain boundary length (Lσ) of the special grain boundary with respect to the total grain boundary length (L) of the crystal grain boundary measured by EBSD method is 25. It is% or more, The pure copper board. The method of claim 2,
Vickers hardness of 40? 90 degree pure copper board. The method of claim 2,
The average grain size measured by the EBSD method is 10? Pure copper plate, characterized in that 120 ㎛. The method of claim 2,
Pure copper plate, characterized in that the sputtering target. The method of claim 2,
Pure copper plate, characterized in that the anode for plating.

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