JP3752083B2 - Abrasive and production method thereof - Google Patents

Description

【００３１】
【表２】

【００３２】
【表３】

【００３３】
【実施例】
次に、本発明の具体例を説明する。
本実施例における研磨剤の製造方法を実施例１及び２について説明する。
実施例１として、研磨剤の基材として、シリコンウエハ−を研磨して出来た使用済みの溶融アルナ（Ａｌ２Ｏ３、約５６重量％）成分とジルコン（ＺｒＳｉＯ４、約４２重量％）成分の混合物から成る研磨剤と研磨によって発生した不純物（約２重量％）とが混在する研磨剤廃棄物を研磨剤の基材として用いた。その研磨剤廃棄物は半固形状の（水分２０％以下）であり、研磨剤が約６５重量％以上で、且つ、溶融アルミナ（Ａｌ２Ｏ３）成分とジルコン（ＺｒＳｉＯ４）成分の混合物が約６５重量％以上含まれており、また、混在する不純物はラップ盤より発生した約１重量％以下のＦｅ成分（磁力で除去出来る物）と、１重量％以下のＳｉ成分及びゴミ類等である。
【００３４】
まず、研磨剤廃棄物から研磨剤の基材以外の不純物を除去する物理的処理工程として、研磨剤廃棄物の基材を湿式分散させ５０ミクロン以上のシリコンウエハ−、チップやゴミ類の不純物を篩いにかけ不純物を除去し、次いで約４５００ガウス程度の磁力を有する永久磁石を用いＦｅ成分を完全に取り除き、それをウレタン製ボ−ルミル中に投入しジルコニヤ玉石と水を加えた後１２時間湿式混合で摩砕粉砕を行った。
【００３５】
この摩砕粉砕物を熱風式の噴霧型乾燥スプレドライヤ−を用い乾燥粉末を得た。
次ぎに、熱処理工程として、この乾燥粉末を高純度のアルミナ製サヤ鉢の中に入れカンタルヒ−タを用いた電気炉により温度９８０〜１７２０℃の範囲内で熱処理を施した。
次ぎに、分級工程として、熱処理が施こされた焼成粉末物を粉砕し分級機にて分級を行い規定値内（５．０ミクロン、１１．０ミクロン、１７．０ミクロン）の粒子径に分け研磨剤を得た。
【００３６】
上記のようにして得られた再生品研磨剤と比較のため未使用の新品研磨剤の化学成分およびＸ線回折分析を施した結果を表１に示した。尚、範囲外の実施例には＊印を付与した。
表１より明らかなようにＮＯ１〜ＮＯ５の熱処理温度が比較的低い９８０〜１４００℃の温度範囲ではアルミナ系結晶形（コランダム、Ａｌ２Ｏ３）とジルコン系結晶形（ＺｒＳｉＯ４）とＳｉＯ２，不明相の混合物形で形成されている。また、Ｎｏ２〜Ｎｏ５はＳｉＯ２及び不明相がほとんど消失されていることが判明した。
また、ＮＯ６〜ＮＯ１０の熱処理温度が高い１５００〜１７２０℃の温度範囲ではジルコニヤ系結晶形（ＺｒＯ２）とムライト系結晶形（Ａｌ２ＳｉＯ５）の２相の混合物形で形成されていることが判明した。
また、化学成分結果より明らかなように再生品研磨剤ＮＯ２〜９は、新品研磨剤と比較して、化学成分値においても同等であり、全く遜色の無いことが確認できた。しかし、ＮＯ１の熱処理温度が９８０℃と低い試料ではＦｅ成分が多く含まれており、そしてＸ線回折結果では不明相が析出し好ましくない傾向にあった。
また、ＮＯ１０の熱処理温度が１７２０℃と高い試料では粉末の粉砕が著しく困難になり実用的ではなかった。
【００３７】
次ぎに、再生品研磨剤と新品研磨剤を用い研磨性能テストを行い表２に示した。
テスト方法としては再生品研磨剤を粒度約１７ミクロンおよび約１０ミクロンおよび約５ミクロンに分け各々水とラッピングオイルに懸濁（スラリ−）させ、ラップ盤を用いて被研磨物（３インチφシリコンウエハ−を２０枚を用い）を研磨して性能テスト（研削速度、表面粗さ、スクラッチ）を次の要領で実施した。
研削速度−ラッピング機械としてＳＰＥＥＤ ＦＡＭ社製マシンを用い、３インチφ用のキャリアを加重１００ｇ／ｃｍ²、回転数６０ｒｐｍ、スラリ−注入量１００ｍｌ／分で研磨した。研磨用スラリ−の組成は、研磨剤６００ｇに対してラッピングオイル４５０ｍｌ、水２２５０ｍｌである。
表面粗さ−粗さ計（東京精密製）を用い被研磨物表面の粗さを測定した。
スクラッチ−５０倍の光学顕微鏡用い表面のスクラッチを測定した。
【００３８】
表２の結果より明らかなように、再生品研磨剤ＮＯ１〜ＮＯ２の熱処理温度が低い９８０℃では研磨剤の粒度に多少は関係しているが研磨速度が遅く、スクラッチでは２０枚中３〜５枚が不良となり好ましくない傾向にあった。
しかし、範囲内のＮＯ３〜ＮＯ１０では研磨速度、表面粗さ、スクラッチ等全ての特性において良好な結果が得られた。特にＮＯ５〜ＮＯ６の熱処理温度が１３００℃の試料が著しく安定で良好な特性を示しており、ＮＯ１２の比較例と比べ、むしろ研磨速度は良好な結果が得られた。
【００３９】
尚、ＮＯ７〜ＮＯ１０で熱処理温度が高い試料では研磨速度が比較的遅くなる傾向にあった、しかし、表面粗さは良好であった。これらの結果から、おそらく生成する結晶相との関係があるものと考えられる。即ち、ＮＯ３〜ＮＯ６ではアルミナ系結晶形（Ａｌ２Ｏ３）とジルコン系結晶形（ＺｒＳｉＯ４）の２相の混合物形で形成（表１を参照）されているが、ＮＯ７〜ＮＯ１０の熱処理温度が高い１５００〜１７００℃ではジルコニヤ系結晶形（ＺｒＯ２）とムライト系結晶形（Ａｌ２ＳｉＯ５）の２相の混合物形で形成（表１を参照）されていることに起因するものと考えられる。これらの結果より、粉末の粒度との関係もあるが被研磨物の表面仕上げには熱処理温度の高い研磨剤を使用することが好ましい。またＮｏ１３〜Ｎｏ１４の粒度が範囲外である３μｍ及び３５μｍでは、特性が悪いものであった。
【００４０】
実施例２として、実施例１で得た研磨剤廃棄物から研磨剤の基材以外の不純物を除去した基材１００に対して、ＭｇＯ、ＣａＣＯ３、Ａｌ２Ｏ３、ＺｎＯ、ＮｉＯ、ＺｒＯ２、ＳｉＯ２、ＣｅＯ２、Ｌａ２Ｏ３成分等を用い表３の添加量になるように秤量し配合した。配合された原料をウレタン製ボ−ルミル中に投入しジルコニヤ玉石と水を加えた後１２時間湿式混合で摩砕粉砕を行った。
この摩砕粉砕物を熱風式の噴霧型乾燥スプレドライヤ−を用い乾燥粉末を得た。
次ぎに、熱処理工程として、この乾燥粉末を高純度のアルミナ製サヤ鉢の中に入れカンタルヒ−タを用いた電気炉により温度９８０〜１７２０℃の範囲内で熱処理を施した。尚、熱処理を施した粉末にＸ線回折分析を施した結果も表３に示した。
【００４１】
次ぎに、分級工程として、熱処理が施こされた焼成粉末物を粉砕し乾式型分級機にて分級を行い規定値内（５．０〜３０．０ミクロン ）の粒子径に分け研磨剤を得た。以上のようにして得られた粒度約１１ミクロンの試料を用い、研磨テスト（テスト方法しとしては実施例１と同様な方法で実施した）を行い表３に示した。
表３の結果より明らかなように、試料ＮＯ１〜ＮＯ４は添加物であるＡｌ２Ｏ３成分の添加量を変化させ熱処理温度を１３００℃一定とした。その結果、ＮＯ２〜ＮＯ３は特性的にも安定した値であるが添加量の少ないＮＯ１および添加量の多いＮＯ４は特性的にも不安定な値であった。
【００４２】
試料ＮＯ５〜ＮＯ１２は添加物であるＡｌ２Ｏ３成分２．５ｗｔ％、ＺｒＯ２成分２．５ｗｔ％と添加量を一定にして熱処理温度を９８０℃〜１７２０℃に変化させた。その結果、ＮＯ５〜ＮＯ９では結晶相がアルミナ系結晶形（Ａｌ２Ｏ３）とジルコン系結晶形（ＺｒＯ２・ＳｉＯ２）の２相の混合物形で形成されていることが判明した、研磨テストではＮＯ６〜ＮＯ９が良好であり、特にＮＯ８の熱処理温度が１３００℃の試料は研磨速度が早く顕著であった。
ＮＯ１０〜ＮＯ１２の熱処理温度が高い所の結晶相はジルコニヤ系結晶形（ＺｒＯ２）とムライト系結晶形（Ａｌ２ＳｉＯ５）の２相の混合物形で形成されていることが判明した、研磨テストにおいて研磨速度は遅くなるが表面粗さは良好であった、しかし範囲外のＮＯ１２では悪い特性であった。
【００４３】
また、ＮＯ１３〜ＮＯ１４、ＮＯ１６〜ＮＯ１７の試料に於いても良好な特性を示しており、特に添加物としてＬａ２Ｏ３成分３．０Ｗｔ％、Ａｌ２Ｏ３成分３．０Ｗｔ％、ＳｉＯ２成分３．０Ｗｔ％、ＺｒＯ２成分３．０Ｗｔ％を添加したＮＯ１６の粉末は結晶粒形が鋭く緻密質で良好な研磨剤であり研磨テストも良好な特性であった。
しかし、添加量が１５．５Ｗｔ％を越えている、範囲外のＮＯ１５では、表面粗さが著しく悪く、また、スクラッチテストにおいて、２０枚中３枚の不良であった。
これらの結果より範囲内の実施例では研磨剤として十分な機能を果たすものであることが確認できた。
以上本発明の実施例について説明をしたが、もちろん本発明は上記実施例に限定されるものではなく、例えば実施例２で添加物として酸化物を用いたが他の塩類あるいは化合物を用いることも可能である。
【００４４】
【発明の効果】
以上から明らかなように本発明によれば、従来廃棄物として処理されていた使用済みの溶融アルナ（Ａｌ２Ｏ３）成分とジルコン（ＺｒＳｉＯ４）成分の混合物から成る研磨剤と研磨によって発生した不純物とが混在する研磨剤廃棄物を研磨剤の基材とし、研磨剤の基材以外の不純物を除去する物理的処理工程と、不純物を除去した研磨剤の基材を熱処理する熱処理工程と、熱処理工程後の研磨剤の基材を粉砕処理し規定値内の粒子径に分ける分級工程を備えた構成より成る研磨剤の製造方法であり、廃棄物から全く新しい安定した新規な研磨剤を得る作用を持った有効な効果がある。
【００４５】
また、使用済みの研磨剤と研磨によって発生した不純物とが混在する研磨剤廃棄物を湿式分散させ磁力を利用する工程を備えた事によつて金属不純物を完全に除去する作用を有し、純度が高く再現性の有る安定した研磨剤としての効果を持った基材となる。
また、不純物が混在する研磨剤廃棄物から研磨剤の基材以外の不純物を除去した後、新しい無機成分を添加し、さらに熱処理と熱処理工程後の研磨剤の基材を粉砕処理し規定値内の粒子径に分ける分級工程を備えたことにより新規な結晶相を持った新しい安定した研磨剤を得る有効な効果がある。
【００４６】
そして、従来の汎用の研磨剤より研磨速度と研磨面の品質を改善した性能の特性を持ち、しかも資源を有効に利用することが出来、さらに製造歩留が高く、安定した信頼性の高い生産性や量産性高く製造することができる有効な効果を有する。
そして、得られた研磨剤は安価で安定した新しい品質の研磨剤であるという効果を有する。また、廃棄処理が必要な研磨剤廃棄物を大幅に減少することが出来るため、環境問題の改善に貢献すると共に、廃棄物処理に要するムダなコストを削減することも出来る。[0001]
BACKGROUND OF THE INVENTION
The present invention polishes silicon wafers for semiconductors, ceramics for electronics, glass, etc.Abrasive manufacturing method.
[0002]
[Prior art]
Conventionally, the abrasive | polishing agent (abrasive grain) used as an industrial abrasive | polishing agent was chosen from the composition of the material suitable for each to-be-polished object. For example, molten alumina is one of the general-purpose abrasives, and there are brown alumina directly made from bauxite and white alumina made from aluminum hydroxide refined by the Bayer method. In addition, there are abrasives in which zircon is mixed with these, and occupy the mainstream of lapping agents for silicon wafers, optical glass, and ceramics for electronics.
Generally, the performance of an abrasive used for polishing is determined by its hardness, toughness, particle size and distribution, as well as the particle shape, such as grinding speed, grinding amount, surface roughness, scratch and the like. Among these, hardness and toughness are determined by the nature of the abrasive material. Therefore, the performance of the same material is adjusted according to the particle size and distribution thereof, and also the particle shape.
In particular, the particle size is the factor having the greatest influence on the performance of the abrasive. When the particle size is large, the polishing efficiency is high, but the polished surface becomes rough and defects such as scratches and chipping increase. On the other hand, those having a small particle diameter have a good roughness on the polished surface, but the polishing rate is low, so they are usually used for so-called finish polishing after rough polishing.
[0003]
Furthermore, since the abrasives actually produced have a particle size distribution and include coarse to fine particles, the particle size distribution is also an important factor. The presence of coarse particles often causes scratches (scratches) and is required to be sufficiently controlled. Extreme fine particles do not contribute to polishing and are not necessary. It has a negative effect. Therefore, it is generally considered that the particle size distribution is as narrow and stable as possible and the balance between the polishing speed and the quality of the polished surface is good, and the importance of classification is regarded as important. In addition, the influence of the particle shape on the polishing performance is important, and it is said that the polishing rate is higher for the one having a flat shape or the one having an edge or corner than the one having a spherical shape.
[0004]
Many of the polishing agents for polishing semiconductor silicon wafers and electronics ceramics currently used are a mixture of brown alumina (Al 2 O 3) and zircon (ZrSiO 4), and the particle diameter within a specified value is 5 microns to 20 microns. It is manufactured and used by setting micron and removing other fine particles and coarse particles.
In addition, as a polishing agent for glass polishing, a polishing agent comprising zirconium oxide as a main component and calcium aluminate and magnesium sulfate added, or a polishing agent composed of a mixture of plate-like alumina single crystal powder and the above-mentioned polishing agent has been proposed. (Japanese Patent Laid-Open Nos. 08-113773 and 03-146484)
[0005]
As described above, the polishing rate and the quality of the polished surface are almost determined by the combination of the particle shape, the particle size, and the distribution thereof. However, both of them basically become rougher as the polishing rate increases. Therefore, there is a demand for an optimal particle shape and particle size that balances the two.
[0006]
[Problems to be solved by the invention]
The conventional abrasives as described above have been manufactured in consideration of various problems.
However, in order to prevent the occurrence of scratches (scratches) at the time of polishing, such an abrasive removes the sharp angle portion of the particle surface into a spherical shape by lengthening the grinding and grinding time (overgrinding). However, due to the excessive pulverization, a large amount of fine particles of 5 microns or less which is the lower limit of the particle diameter within the specified value is generated, and about 40% of the raw material is wasted. Therefore, many of the current abrasives are very expensive, and there is a problem that a limited amount of valuable resources are wasted.
[0007]
On the other hand, once used, the polishing agent contains impurities such as ceramics generated from the object to be polished at the time of polishing, silicon scraps, iron powder generated from the lapping machine, and fine particles generated by abrasion of the polishing agent itself. Since it is in a mixed state, it is currently treated as waste. In order to solve these problems, a method of recovering the abrasive has been proposed. (Japanese Patent Laid-Open No. 08-003543)
[0008]
JP-A-08-003543 describes the removal of soluble impurities by chemical treatment using as raw materials polishing waste mainly composed of brown alumina and zircon sand in which used abrasives and impurities generated by polishing are mixed. Then, a method of removing fine particles outside the specified value by pulverizing was described, which was an excellent method for recycling waste.
[0009]
However, in the above method, strong acids such as hydrochloric acid and sulfuric acid are used as chemical treatments, so there are dangers during work, and environmental problems of these wastewater treatments are greatly closed, and there are many restrictions on reproducibility and workability. . Furthermore, there has been a problem that a change in the component ratio occurs when the raw material itself is dissolved, and the characteristics are largely lost.
[0010]
The present invention solves the above-mentioned conventional problems, and its purpose is to produce an abrasive with high accuracy and high productivity and low productivity without losing conventional high polishing performance at low cost. It is another object of the present invention to provide an abrasive that can be used and that can greatly contribute to reducing the amount of abrasive waste and a method for producing the same.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present inventionaluminaAbrasive waste composed of a mixture of (Al2O3) component and zircon (ZrSiO4) component and impurities generated by polishing is used as the abrasive base material. From the abrasive waste to the abrasive base material other than the abrasive base material Physical treatment process to remove impurities and within a temperature range of 1000-1700 ° CHeat treatment withFrom a configuration with a heat treatment step and a classification step that pulverizes the abrasive waste base material after the heat treatment step and divides it into particle sizes within a specified valueThe physical treatment step is a step of wet-dispersing abrasive waste containing a used abrasive and impurities generated by polishing and removing metal impurity components by magnetic force. . As a result, it becomes possible to recycle used abrasives that have been treated as conventional polishing waste, and an abrasive having performance superior to that of unused abrasives can be obtained at low cost.
[0012]
Also used meltaluminaAfter removing impurities other than the base material of the abrasive from the abrasive waste containing a mixture of the (Al2O3) component and the zircon (ZrSiO4) component and impurities generated by polishing, a new inorganic component is added. New and unprecedented abrasivebe able to.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention isaluminaAn abrasive waste composed of a mixture of an (Al2O3) component and a zircon (ZrSiO4) component and impurities generated by polishing is used as the abrasive base material. From the abrasive waste to the abrasive base material, A physical treatment step for removing impurities other than the above, and the substrate of the abrasive waste from which the impurities have been removed within a temperature range of 1000 to 1700 ° C.Heat treatment withFrom the configuration provided with a heat treatment step and a classification step of pulverizing the abrasive waste base material after the heat treatment step and dividing it into particle sizes within a specified valueThe physical treatment step is a step of wet-dispersing abrasive waste containing a used abrasive and impurities generated by polishing and removing metal impurity components by magnetic force. .
[0014]
By using an abrasive waste containing a mixture of a molten aluna (Al 2 O 3) component and a zircon (ZrSiO 4) component and impurities generated by polishing as an abrasive base, an acute angle of the abrasive surface is obtained. Thus, the fine particles are present as they are, the sintering reaction during the heat treatment is facilitated, and the base material has an excellent effect for obtaining the desired reaction product.
By applying a physical treatment to remove impurities other than the base material of the abrasive, the base material has an effect as a stable abrasive with high purity and reproducibility.
It has the effect of obtaining a novel abrasive base material having a new crystal phase by subjecting the abrasive waste base material from which impurities have been removed to a heat treatment within a temperature range of 1000 to 1700 ° C.
A temperature of 1000 ° C. or lower is not preferable because the particle size is unstable and the polishing effect is reduced. If the temperature is 1700 ° C. or higher, the crystal grains grow significantly and the grains become brittle, so the effect of obtaining a stable quality abrasive is weakened.
[0015]
The action of obtaining a completely new and stable abrasive with a new particle size within the specified value from the waste by pulverizing the substrate of the abrasive waste after heat treatment and classifying it into particles within the specified value. Have
[0016]
Also,As a physical treatment process to remove impurities other than the abrasive base material from the abrasive waste, wet waste dispersion of used abrasive and impurities generated by polishing, and metal impurities component by magnetically dispersing With a process of removingTherefore, the wet and dispersible abrasive waste containing the used abrasive and impurities generated by polishing separates and disperses the metal impurity components that were firmly attached to the abrasive from the abrasive. It becomes easy to be made and has a function of completely removing metal impurities by using magnetic force, and becomes a base material having an effect as a stable abrasive having high purity and reproducibility.
[0018]
According to the second aspect of the present invention, there is provided a polishing agent waste comprising a polishing agent comprising a mixture of a used molten alumina (Al2O3) component and a zircon (ZrSiO4) component and impurities generated by polishing. As a base material of the above,After removing impurities other than the abrasive base material from the abrasive waste, with respect to the abrasive base material 100 containing the mixture of the molten alumina (Al2O3) component and the zircon (ZrSiO4) component, MgO, CaO, Al2O3, Add one or more of ZnO, NiO, ZrO2, SiO2, CeO2, and La2O3 components within a range of 1 to 15.5 wt%, and perform heat treatment within a temperature range of 1000 to 1700 ° C. It consists of the structure provided with.
[0019]
In addition, a new abrasive having a new crystal phase can be obtained by adding the above-mentioned additive component in an addition amount within the range and performing a heat treatment at a temperature range of 1000 to 1700 ° C. Further, as an abrasive It has the effect of controlling the excellent hardness and physical properties of the particle shape, and has a good effect as an abrasive base material.
[0020]
As the operation of the additive component, the addition of MgO can widen the temperature range of the reaction product and control the particle size of the stable crystal particle phase to be small, so that a dense abrasive powder can be obtained. The addition of CaO can widen the sintering temperature range of the reaction product. The addition of Al2O3 can widen the sintering temperature range of the reaction product and increase the hardness of the powder particles. The addition of ZnO can lower the sintering temperature of the reaction product and suppress the growth of crystal grain size. The addition of NiO can widen the sintering temperature range of the reaction product to improve the sinterability and obtain dense powder particles. Addition of ZrO2 can widen the sintering temperature range of the reaction product to improve the sinterability and obtain powder particles with high hardness. The addition of SiO2 can widen the sintering temperature range of the reaction product to improve the sinterability and obtain powder particles with high hardness. The addition of CeO2 can widen the sintering temperature range and improve the sinterability and obtain dense powder particles. The addition of La2O3 can suppress the growth of the crystal grain size, and as a result, dense powder particles can be obtained.
[0021]
In addition, as the MgO content becomes less than 1 wt% as an additive to the abrasive base material 100, it becomes difficult to control the particle size of the stable crystalline particle phase by expanding the temperature range of the reaction product, As a result, it becomes difficult to obtain a dense abrasive powder, which is not preferable. As MgO exceeds 15.5 wt%, the sinterability of the powder deteriorates and the amount of pores tends to increase. As CaO becomes less than 1 wt%, the effect of expanding the sintering temperature range of the reaction product is small. As CaO exceeds 15.5 wt%, it becomes difficult to obtain a dense abrasive powder. As Al2O3 becomes less than 1 wt%, the effect of increasing the sintering temperature of the reaction product is reduced, and as a result, the effect of obtaining a powder having high hardness is weakened. As Al2O3 exceeds 15.5 wt%, the sinterability of the powder tends to deteriorate and the amount of pores tends to increase, such being undesirable.
[0022]
As ZnO is less than 1 wt%, the effect of lowering the sintering temperature of the reaction product to obtain a stable crystal grain size is small. As ZnO exceeds 15.5 wt%, the effect of increasing the compactness by lowering the sintering temperature of the powder is weak. As NiO is less than 1 wt%, the effect of increasing the sintering temperature range of the reaction product and improving the sinterability is small. As NiO exceeds 15.5 wt%, the effect of obtaining dense powder particles becomes weak, which is not preferable.
As ZrO2 becomes less than 1 wt%, the effect of expanding the sintering temperature range of the reaction product and improving the sinterability becomes weak, and as a result, it becomes difficult to obtain powder particles with high hardness. As ZrO2 exceeds 15.5 wt%, the amount of pores of the powder tends to increase, which is not preferable.
[0023]
As SiO2 becomes less than 1 wt%, the effect of increasing the sintering temperature range of the reaction product and improving the sinterability is small. As SiO2 exceeds 15.5 wt%, the sinterability of the powder becomes unstable, and as a result, it becomes difficult to obtain powder particles with high hardness, which is not preferable. As CeO2 becomes less than 1 wt%, the effect of expanding the sintering temperature range and improving the sinterability is small. As CeO2 exceeds 15.5 wt%, the effect of expanding the sintering temperature range of the powder becomes small, and it tends to be difficult to obtain dense powder particles, which is not preferable.
As La2O3 becomes less than 1 wt%, the effect of obtaining a stable crystal grain size becomes weaker. As La2O3 exceeds 15.5 wt%, the effect of obtaining stable dense powder particles tends to decrease, which is not preferable.
[0024]
In the heat treatment of the abrasive base material to which the above components are added within the range, as the firing temperature becomes less than 1000 ° C., the sintering of the powder does not proceed sufficiently and good powder particles cannot be obtained, so the polishing effect is reduced. It is not preferable. On the other hand, when the temperature is 1700 ° C. or higher, the crystal grains tend to grow remarkably, and the grains become brittle and the target properties are deteriorated. This is not preferable because an abrasive having a stable quality cannot be obtained.
[0025]
Claims of the invention3The main component crystal phase of the abrasive after heat treatment in the temperature range of 1000 to 1700 ° C. is a mixture phase of molten alumina (Al 2 O 3) and zircon (ZrSiO 4), zirconium (ZrO 2) and mullite ( It consists of a structure with a mixture phase of Al2SiO5).
[0026]
Incidentally, the abrasive having a mixed phase of molten alumina (Al2O3) and zircon (ZrSiO4) as the main component crystal phase has relatively hard particles and has an effect of increasing the grinding speed of the polished article. Moreover, the abrasive of the mixed phase of zirconium (ZrO2) and mullite (Al2SiO5) has relatively soft particles and has an effect of improving the surface quality of the polished article.
[0027]
Claims of the invention4The invention described in 1 is completely new from the waste by subjecting the substrate of the abrasive waste after the heat treatment step to a pulverization process and dividing the particle size within a specified value into 5.0 to 30.0 microns. It has the effect of obtaining a wide abrasive with a stable and new particle size within a specified value.
[0029]
Hereinafter, embodiments of the present invention will be described with reference to (Table 1), (Table 2), and (Table 3).
[0030]
[Table 1]

[0031]
[Table 2]

[0032]
[Table 3]

[0033]
【Example】
Next, specific examples of the present invention will be described.
The manufacturing method of the abrasive | polishing agent in a present Example is demonstrated about Example 1 and 2. FIG.
As Example 1, a mixture of a used molten aluna (Al 2 O 3, about 56 wt%) component and a zircon (ZrSiO 4, about 42 wt%) component obtained by polishing a silicon wafer as a base material of an abrasive was used. Abrasive waste containing a mixture of abrasive and impurities (about 2% by weight) generated by polishing was used as a base material for the abrasive. The abrasive waste is semi-solid (moisture 20% or less), the abrasive is about 65% by weight or more, and the mixture of the molten alumina (Al2O3) component and the zircon (ZrSiO4) component is about 65% by weight. The impurities contained in the mixture are about 1 wt% or less of the Fe component (thing that can be removed by magnetic force) generated from the lapping machine, and 1 wt% or less of the Si component and dust.
[0034]
First, as a physical treatment step for removing impurities other than the abrasive base material from the abrasive waste, the abrasive waste base material is wet-dispersed to remove impurities of silicon wafers, chips and garbage of 50 microns or more. Impurities are removed by sieving, and then the Fe component is completely removed using a permanent magnet having a magnetic force of about 4500 gauss, which is put into a urethane ball mill, zirconia cobblestone and water are added, and then wet mixed for 12 hours. Trituration was carried out.
[0035]
The ground and ground product was dried using a hot air spray spray dryer.
Next, as a heat treatment step, this dry powder was placed in a high-purity alumina sheath pot and subjected to a heat treatment within a temperature range of 980 to 1720 ° C. using an electric furnace using a cantal heater.
Next, as a classification step, the fired powder that has been heat-treated is pulverized and classified with a classifier, and divided into particle sizes within specified values (5.0 microns, 11.0 microns, 17.0 microns). An abrasive was obtained.
[0036]
Table 1 shows the chemical components and the results of X-ray diffraction analysis of an unused new abrasive for comparison with the recycled abrasive obtained as described above. In addition, * mark was provided to the Example outside the range.
As is apparent from Table 1, in the temperature range of 980 to 1400 ° C. where the heat treatment temperatures of NO1 to NO5 are relatively low, a mixture form of alumina crystal form (corundum, Al 2 O 3), zircon crystal form (ZrSiO 4), SiO 2 and unknown phase. It is formed with. Moreover, it turned out that No2-No5 have almost disappeared SiO2 and the unknown phase.
Further, it was found that in the temperature range of 1500 to 1720 ° C. where the heat treatment temperature of NO 6 to NO 10 is high, it is formed in a two-phase mixture form of zirconia crystal form (ZrO 2) and mullite crystal form (Al 2 SiO 5).
Further, as apparent from the chemical component results, it was confirmed that the recycled product abrasives NO2 to NO9 were equivalent in chemical component values as compared with the new abrasives and were completely inferior. However, a sample with a low heat treatment temperature of NO1 as low as 980 ° C. contained a large amount of Fe component, and the X-ray diffraction result showed that an unknown phase was precipitated, which was not preferable.
In addition, in a sample having a heat treatment temperature of NO10 as high as 1720 ° C., powder pulverization was extremely difficult, which was not practical.
[0037]
Next, a polishing performance test was performed using a recycled abrasive and a new abrasive, and the results are shown in Table 2.
As a test method, the recycled product abrasive is divided into particle sizes of about 17 microns, about 10 microns, and about 5 microns, suspended in water and wrapping oil (slurry), and the object to be polished (3 inch φ silicon) using a lapping machine. The performance test (grinding speed, surface roughness, scratch) was performed in the following manner by polishing 20 wafers).
Grinding speed-Using a machine made by SPEED FAM as a lapping machine, a carrier for 3 inch φ is loaded with 100 g / cm²Polishing was performed at a rotational speed of 60 rpm and a slurry injection rate of 100 ml / min. The composition of the polishing slurry is 450 ml of wrapping oil and 2250 ml of water with respect to 600 g of abrasive.
The roughness of the surface of the workpiece was measured using a surface roughness-roughness meter (manufactured by Tokyo Seimitsu).
Scratch—The surface scratch was measured using an optical microscope of 50 times magnification.
[0038]
As is apparent from the results in Table 2, the heat treatment temperature of the recycled abrasives NO1 to NO2 is low at 980 ° C., which is somewhat related to the particle size of the abrasive, but the polishing rate is slow. The sheet was unsatisfactory because it became defective.
However, with NO3 to NO10 within the range, good results were obtained in all characteristics such as polishing rate, surface roughness, scratch and the like. In particular, a sample with a heat treatment temperature of NO5 to NO6 of 1300 ° C. was remarkably stable and showed good characteristics, and the polishing rate was better than that of the comparative example of NO12.
[0039]
Incidentally, the samples with NO7 to NO10 having a high heat treatment temperature tended to have a relatively low polishing rate, but the surface roughness was good. From these results, it is considered that there is probably a relationship with the crystal phase to be formed. That is, NO3 to NO6 are formed in a two-phase mixture form of alumina crystal form (Al2O3) and zircon crystal form (ZrSiO4) (see Table 1), but NO7 to NO10 have a high heat treatment temperature of 1500 to At 1700 ° C., it is considered to be caused by the formation of a two-phase mixture of a zirconia crystal form (ZrO 2) and a mullite crystal form (Al 2 SiO 5) (see Table 1). From these results, although there is a relationship with the particle size of the powder, it is preferable to use an abrasive having a high heat treatment temperature for finishing the surface of the object to be polished. In addition, when the particle sizes of No. 13 to No. 14 were outside the range of 3 μm and 35 μm, the characteristics were poor.
[0040]
As Example 2, with respect to the base material 100 from which impurities other than the base material of the abrasive were removed from the abrasive waste obtained in Example 1, MgO, CaCO 3, Al 2 O 3, ZnO, NiO, ZrO 2, SiO 2, CeO 2, Using La2O3 component, etc., it was weighed and blended so as to have the addition amount shown in Table 3. The blended raw materials were put into a urethane ball mill, zirconia cobblestone and water were added, and then milled and pulverized by wet mixing for 12 hours.
The ground and ground product was dried using a hot air spray spray dryer.
Next, as a heat treatment step, this dry powder was placed in a high-purity alumina sheath pot and subjected to a heat treatment within a temperature range of 980 to 1720 ° C. using an electric furnace using a cantal heater. The results of X-ray diffraction analysis on the heat-treated powder are also shown in Table 3.
[0041]
Next, as a classification step, the fired powder that has been heat-treated is pulverized and classified by a dry type classifier to obtain an abrasive that is divided into particle sizes within a specified value (5.0 to 30.0 microns). It was. Using the sample having a particle size of about 11 microns obtained as described above, a polishing test (the test method was carried out in the same manner as in Example 1) was performed and shown in Table 3.
As is clear from the results in Table 3, the heat treatment temperature was kept constant at 1300 ° C. for samples NO1 to NO4 by changing the amount of additive Al2O3 component. As a result, NO2 to NO3 were stable values in terms of characteristics, but NO1 having a small addition amount and NO4 having a large addition amount were unstable values in terms of characteristics.
[0042]
Samples Nos. 5 to 12 had additive amounts of Al 2 O 3 component 2.5 wt% and ZrO 2 component 2.5 wt%, which were additives, and the heat treatment temperature was changed from 980 ° C. to 1720 ° C. with a constant addition amount. As a result, it was found that in NO5 to NO9, the crystal phase was formed in the form of a mixture of two phases of alumina crystal form (Al2O3) and zircon crystal form (ZrO2 · SiO2). The sample with good heat treatment temperature of NO8, especially 1300 ° C., had a high polishing rate and was remarkable.
It has been found that the crystal phase where the heat treatment temperature of NO10 to NO12 is high is formed as a mixture of two phases of zirconia crystal form (ZrO2) and mullite crystal form (Al2SiO5). Although it was slow, the surface roughness was good, but with NO12 outside the range, it was a bad characteristic.
[0043]
In addition, the NO13 to NO14 and NO16 to NO17 samples also show good characteristics, and in particular, La2O3 component 3.0 Wt%, Al2O3 component 3.0 Wt%, SiO2 component 3.0 Wt%, ZrO2 component as additives The powder of NO16 to which 3.0 Wt% was added was a fine abrasive with a sharp crystal grain shape and a good polishing test.
However, in the case of NO15 out of the range where the addition amount exceeds 15.5 Wt%, the surface roughness was remarkably poor, and in the scratch test, 3 out of 20 sheets were defective.
From these results, it was confirmed that Examples within the range fulfilled a sufficient function as an abrasive.
Although the embodiments of the present invention have been described above, of course, the present invention is not limited to the above embodiments. For example, oxides are used as additives in Example 2, but other salts or compounds may be used. Is possible.
[0044]
【The invention's effect】
As is apparent from the above, according to the present invention, a polishing agent composed of a mixture of used molten aluna (Al2O3) component and zircon (ZrSiO4) component, which has been treated as waste, is mixed with impurities generated by polishing. The abrasive waste to be used as an abrasive base material, a physical treatment step for removing impurities other than the abrasive base material, a heat treatment step for heat-treating the abrasive base material from which the impurities have been removed, and a post-heat treatment step This is a method of manufacturing an abrasive comprising a classifying process that pulverizes the base material of the abrasive and divides it into particle sizes within a specified value, and has the effect of obtaining a completely new and stable new abrasive from waste. There is an effective effect.
[0045]
In addition, it has the function of completely removing metal impurities by providing a process that uses a magnetic force to disperse abrasive waste containing used abrasives and impurities generated by polishing. Therefore, it becomes a base material having an effect as a stable abrasive having high reproducibility.
In addition, after removing impurities other than the abrasive base material from the abrasive waste mixed with impurities, a new inorganic component is added, and the abrasive base material after the heat treatment and heat treatment process is pulverized to within the specified value. By providing a classification step for dividing the particles into different particle diameters, there is an effective effect of obtaining a new stable abrasive having a novel crystal phase.
[0046]
In addition, it has performance characteristics that improve the polishing speed and quality of the polished surface compared to conventional general-purpose abrasives, can use resources effectively, has a high production yield, and is stable and reliable. It has an effective effect that can be manufactured with high productivity and mass productivity.
And the obtained abrasive | polishing agent has an effect that it is an inexpensive and stable new quality abrasive | polishing agent. In addition, since the abrasive waste that needs to be disposed of can be greatly reduced, it contributes to the improvement of environmental problems and can reduce the wasteful cost required for the disposal of waste.

Claims (4)

The abrasive waste and impurities generated by polishing and used for fused alumina (Al2 O3) component and zircon (ZrSiO4) abrasives comprising a mixture of components are mixed as a substrate of the abrasive, the polishing from the abrasive waste a physical treatment step of removing impurities other than the base material of the agent, the heat treatment step of the substrate of the abrasive waste to remove the impurities to a heat treatment within a temperature range of 1000 to 1700 ° C., the polishing after the heat treatment step A method for producing an abrasive comprising a classification step of pulverizing a base material of an agent waste and dividing it into particle sizes within a specified value ,
Manufacturing of an abrasive characterized in that the physical treatment step is a step of wet-dispersing an abrasive waste mixed with used abrasives and impurities generated by polishing, and removing metal impurity components by magnetic force. Method. Abrasive waste consisting of a mixture of used fused alumina (Al2O3) and zircon (ZrSiO4) components and impurities generated by polishing is used as a base material for the abrasive, and polishing is performed from the abrasive waste. after removing impurities other than the base material of agents, the relative fused alumina (Al2 O3) component and zircon (ZrSiO4) abrasive substrate 100 comprising a mixture of components, MgO, CaO, Al2O3, ZnO , NiO, ZrO2, SiO2 A polishing agent characterized by adding one or more of CeO2 and La2O3 in a range of 1 to 15.5 wt% and heat-treating at a temperature of 1000 to 1700 ° C. Production method. The main component crystal phase of the abrasive after heat treatment in the temperature range of 1000 to 1700 ° C. is composed of a mixture phase of molten alumina (Al 2 O 3) and zircon (ZrSiO 4) or a ZrO 2 and Al 2 SiO 5 phase. Item 3. A method for producing an abrasive according to Item 1 or 2 . 3. Polishing according to claim 1 or 2 , characterized in that it comprises a classification step of grinding the abrasive waste base material after the heat treatment step into a particle size within a specified value and dividing it into 5.0 to 30.0 microns. Manufacturing method