TW201943642A - A fabrication method of fine spherical aluminum nitride powder which is simple and capable of producing fine spherical aluminum nitride for mass production - Google Patents

Abstract

A fabrication method of a fine spherical aluminum nitride powder includes the steps of: (A) A spherical aluminum oxide and a carbonaceous material are provided and placed together in a solvent for wet mixing to form a mixed slurry. Because of the excellent fluidity of spherical aluminum oxide, the homogeneity and solid content are higher during the mixing process, which can increase the production yield and eliminate the requirement of grinding balls to avoid contamination of the products caused by grinding balls. The spherical aluminum oxide and the carbonaceous material may also be subjected directly to dry mixing to form a mixture. (B) The mixed slurry is then filtered to obtain a wet cake. The wet cake is then dried to obtain a mixed powder. (C) The mixed powder or the mixture is then placed in a crucible and subjected to a carburization treatment in air or inert gas or vacuum atmosphere. Then, a carbothermal reduction reaction is carried out in a furnace in which a nitrogen-containing gas is introduced, and finally a decarburization treatment is carried out in an oven under an oxygen-containing atmosphere to obtain spherical aluminum nitride of 0.2 to 10 [mu]m. Such process is simple and the production yield is high, and the process is capable of producing fine spherical aluminum nitride. It is a production method with great potential for mass production.

Description

一種製造微細球形氮化鋁粉末的方法    Method for manufacturing fine spherical aluminum nitride powder   

本發明是關於一種微細球形氮化鋁粉末的製造方法。 The invention relates to a method for manufacturing fine spherical aluminum nitride powder.

氮化鋁(AlN)具有高的熱傳導率，良好的電絕緣性，及熱膨脹係數接近於矽(4.2×10-6/℃)及砷化鎵(5.7×10-6/℃)，常被應用於半導體與微電子電路封裝基板、高亮度LED晶片承載基板、車用電子與照明元件、高功率電子元件散熱材料等。 Aluminum nitride (AlN) has high thermal conductivity, good electrical insulation, and a thermal expansion coefficient close to that of silicon (4.2 × 10-6 / ℃) and gallium arsenide (5.7 × 10-6 / ℃). It is often used Used in semiconductor and microelectronic circuit packaging substrates, high-brightness LED chip carrier substrates, automotive electronics and lighting components, and high-power electronic component heat sink materials.

球形氮化鋁粉末因為可以有較高的堆積密度及填充率，可提供熱傳最短的路徑，所以導熱較一般非球形氮化鋁粉末(市售產品多為不規則狀)來得高。 Spherical aluminum nitride powder has higher bulk density and filling rate, and can provide the shortest path of heat transfer, so the thermal conductivity is higher than that of general non-spherical aluminum nitride powder (commercial products are mostly irregular).

目前市面販售的球形氮化鋁粉末，多由非球形氮化鋁粉，添加黏結劑與助燒結劑和其他添加劑混合後，配成漿料，再利用噴霧乾燥與燒結，製得球形氮化鋁粉。這樣生產的球形氮化鋁粉粒徑，多在數十微米級(μm)以上，而且因為添加助燒結劑，燒結助劑會存在於氮化鋁顆粒界面，而讓導熱值因此變小。另外，燒結得到的球形氮化鋁，表面存在很多晶界，造成表面不平滑、不夠緻密，也讓導熱值下降。而因為氮化鋁粉容易水解，因此氮 化鋁粉的造粒必須採用有機溶劑系統，這樣的造粒必須添加防爆設備，設備相當昂貴，增加了資本支出的負擔。 Spherical aluminum nitride powders currently on the market are mostly non-spherical aluminum nitride powders, which are mixed with a binder, sintering aid and other additives to form a slurry, which is then spray dried and sintered to obtain spherical nitrides. Aluminum powder. The particle size of the spherical aluminum nitride powder produced in this way is more than tens of micrometers (μm), and because the sintering aid is added, the sintering aid will exist at the interface of the aluminum nitride particles, and the thermal conductivity value will be reduced accordingly. In addition, the spherical aluminum nitride obtained by sintering has many grain boundaries on the surface, which causes the surface to be smooth and not dense enough, and also reduces the thermal conductivity value. And because aluminum nitride powder is easy to hydrolyze, the granulation of aluminum nitride powder must use an organic solvent system. Such granulation must be equipped with explosion-proof equipment. The equipment is quite expensive and increases the burden of capital expenditure.

目前市面上的奈米或亞微米氮化鋁粉末，多以化學法合成，純度雖高，但相當昂貴，多為學術上研究使用，無法被業界量產，因此業界使用的氮化鋁粉末多為微米級。以微米級的氮化鋁粉末為原料，添加助燒結劑與黏結劑等充分混合後，配成漿料，再透過噴霧造粒及高溫燒結、球磨等製程，製得的球形氮化鋁粉末多為數十微米。 At present, nano- or sub-micron aluminum nitride powders on the market are mostly synthesized by chemical methods. Although the purity is high, they are quite expensive. They are mostly used for academic research and cannot be mass-produced by the industry. Therefore, many aluminum nitride powders are used in the industry. Micron level. Micron-level aluminum nitride powder is used as a raw material, and after adding a sintering aid and a binder, the mixture is fully mixed, and then a slurry is prepared, and then through spray granulation, high temperature sintering, ball milling and other processes, many spherical aluminum nitride powders are obtained. It is tens of microns.

中國專利第103079996號，將氧化鋁、稀土金屬或鹼土金屬化合物和碳粉混合後，在1620~1900℃進行10-20小時的氮化處理，得到平均粒徑3~30μm球形氮化鋁，因反應時間太長，容易出現條狀產物，反應不易控制。 Chinese Patent No. 103079996, after mixing alumina, rare earth metal or alkaline earth metal compound and carbon powder, nitriding treatment at 1620 ~ 1900 ° C for 10-20 hours, to obtain spherical aluminum nitride with an average particle diameter of 3 ~ 30μm, because The reaction time is too long, and strip-like products are prone to occur, and the reaction is not easy to control.

中國專利第101525238號，將氮化鋁粉體與球化除氧輔料經球磨混合後，於氮氣或氬氣氣氛中，燒結1550-1900℃持溫0-20小時，在經過酸洗、水洗、乾燥後，得到含氧量<1wt%，平均粒徑5.2~7.2μm球形氮化鋁。 Chinese Patent No. 101525238, after mixing aluminum nitride powder and nodularized deoxidizing auxiliary materials by ball milling, sintering in a nitrogen or argon atmosphere at 1550-1900 ° C for 0-20 hours, after pickling, water washing, After drying, spherical aluminum nitride having an oxygen content of <1% by weight and an average particle diameter of 5.2 to 7.2 μm is obtained.

中國專利第103588182號，將球形鋁粉、氮化鋁粉、氯化銨粉混合球磨，再放入多孔石墨坩堝進行燃燒合成，獲得灰白色的1~2.5μm球形氮化鋁。 In Chinese Patent No. 103588182, spherical aluminum powder, aluminum nitride powder, and ammonium chloride powder are mixed and ball milled, and then placed in a porous graphite crucible for combustion synthesis to obtain off-white spherical aluminum nitride of 1 to 2.5 μm.

中國專利第104909762號，將0.5~5μm的氮化鋁粉、黏結劑、助燒結劑、分散劑，放入有機溶劑中球磨12hr，再利用噴霧乾燥與燒結及球磨，製得5~80μm球形氮化鋁。 Chinese Patent No. 104909762, 0.5 ~ 5μm aluminum nitride powder, bonding agent, sintering aid, dispersant was placed in an organic solvent and ball-milled for 12hr, and then spray-dried, sintered and ball-milled to obtain 5 ~ 80μm spherical nitrogen Aluminium.

美國專利第20140042675號，將氮化鋁粉放入酒精溶劑中球磨1hr，磨到粒徑2~3μm，再加入黏結劑、助燒結劑、分散劑，混合22hr，再利用噴霧乾燥與燒結及球磨，製得平均粒徑110.7μm球形氮化鋁。 U.S. Patent No. 20140042675, ball milling the aluminum nitride powder in an alcohol solvent for 1 hr to a particle size of 2 to 3 μm, then add a binder, sintering aid, dispersant, and mix for 22 hr, then use spray drying and sintering and ball milling , A spherical aluminum nitride having an average particle diameter of 110.7 μm was prepared.

台灣發明專利號碼I579231，將氧化鋁粉和含碳材料做原料，加入樹脂製成漿料，再利用噴霧乾燥、碳化、碳化還原與燒結及脫碳，製得粒徑10~80μm球形氮化鋁。 Taiwan Invention Patent No. I579231, using aluminum oxide powder and carbon-containing materials as raw materials, adding resin to make a slurry, and then using spray drying, carbonization, carbonization reduction and sintering and decarburization to obtain spherical aluminum nitride with a particle size of 10 ~ 80 μm .

台灣發明專利號碼I573758，是以噴霧乾燥所得的氧化鋁粉或氧化鋁水合物之球狀造粒物做起始原料，之後碳化還原，製得粒徑10~200μm球形氮化鋁。 Taiwan Invention Patent No. I573758 uses spherical alumina powder or alumina hydrate obtained as a starting material by spray drying, and then carbonizes and reduces to obtain a spherical aluminum nitride with a particle size of 10 to 200 μm.

隨著小型化需求、高填充率及高導熱需求，目前業界急需發展簡易製備奈米級到亞微米球形氮化鋁粉的方法，以符合客戶高填充率的需求。 With the demand for miniaturization, high filling rate and high thermal conductivity, the industry urgently needs to develop a simple method for preparing nanometer to sub-micron spherical aluminum nitride powder to meet the needs of customers with high filling rate.

鑑於上述習知技術，本發明的主要目的在提供一種微細球形氮化鋁的製造方法，其中包含以球形氧化鋁為原料，無需添加助燒結劑，也不需噴霧造粒與球磨，就可以製備球形氮化鋁粉末。獲得的球形氮化鋁平均粒徑可以小至0.25μm，大到10μm。 In view of the above-mentioned conventional technology, the main object of the present invention is to provide a method for manufacturing fine spherical aluminum nitride, which contains spherical alumina as a raw material, and can be prepared without the addition of a sintering aid, spray granulation and ball milling. Spherical aluminum nitride powder. The average particle diameter of the obtained spherical aluminum nitride can be as small as 0.25 μm and as large as 10 μm.

本發明採用容易取得、成本較低、非噴霧造粒的球形氧化鋁粉做原料，不但可以簡化製程時間與資本投資，並可製備出微細的球形氮化鋁。這樣製備的微細球形氮化鋁粉，表面光滑幾乎看不到晶界，這與目前所用噴霧造粒再燒結製程所得的球形氮化 鋁，表面明顯有燒結的晶界結構截然不同，光滑的結構得到的導熱值，高出造粒再燒結製程的許多。另外，因為無需燒結處理，因此無添加助燒結劑，讓氮化鋁純度及表面光滑度大幅提升，這也是這樣製程得到的球形氮化鋁導熱值較高的原因之一。獲得的球形氮化鋁平均粒徑可以小至0.25μm到10μm。如此一來，可以簡易製備符合業界期待的微細球形氮化鋁粉。 The invention adopts spherical aluminum oxide powder which is easy to obtain, has low cost, and is not spray-granulated as raw materials, which not only can simplify the process time and capital investment, but also can prepare fine spherical aluminum nitride. The fine spherical aluminum nitride powder prepared in this way has a smooth surface and almost no grain boundaries. This is completely different from the spherical aluminum nitride obtained by the spray granulation and resintering process currently used. The obtained thermal conductivity value is much higher than the granulation and re-sintering process. In addition, because no sintering treatment is required, no sintering aid is added, which greatly improves the purity and surface smoothness of aluminum nitride, which is one of the reasons for the high thermal conductivity of spherical aluminum nitride obtained by this process. The obtained spherical aluminum nitride can have an average particle diameter as small as 0.25 μm to 10 μm. In this way, it is possible to easily prepare fine spherical aluminum nitride powder that meets industry expectations.

為了達到上述目的，根據本發明提出的方案之一，是提供一種球形氮化鋁的製造方法，步驟包括：(A)是採用已高溫成形的0.2~10μm的球形氧化鋁，與含碳原料，一同放入溶劑(酒精或異丙醇或水或甲苯等極性溶劑或是非極性溶劑或是兩性溶劑)中進行濕式混合，形成一混合漿料。因球形氧化鋁具有很好的流動性，在混合過程可以有較高混合均勻性及的固含量(20-90vol%)，可提高製造產量，也因此無需使用磨球，避免磨球對產品污染，這樣的產品比球磨混合得到的產品，純度來得高。已成形的0.2~10μm的球形氧化鋁，與含碳原料，也可以直接進行乾式混合(無需任何溶劑)，形成一混合物。不論濕式混合或乾式混合，氧化鋁與碳的莫耳配比，均控制在1：3.1~1：12。(B)之後將混合漿料，進行抽氣或離心過濾，獲得濕餅。再將濕餅放入烘箱，進行60~160℃，烘乾1~96hr，獲得的混合粉體。這與目前大家常使用的噴霧乾燥不同，這樣的製程可以有較大的製造產量，較低的設備投資，便宜的製造成本。混合物甚至可省略此製程，大幅降低製造成本。(D)將混合粉體或混合物再放入坩堝中，在 空氣或惰性氣體或真空氣氛中進行300℃~1200℃，持溫1-96小時的碳化處理。接著在通有含氮氣體的爐子中進行1550℃~1900℃，持溫1-96小時的碳熱還原、最後在含氧氣氛的爐子中進行550℃~900℃，持溫1-96小時的脫碳處理，以獲得表面光滑的球形氮化鋁。 In order to achieve the above object, one of the solutions proposed by the present invention is to provide a method for manufacturing a spherical aluminum nitride, the steps include: (A) using a spherical alumina having a high temperature of 0.2 to 10 μm, and a carbon-containing raw material, Put them together in a solvent (polar solvents such as alcohol or isopropanol or water or toluene or non-polar solvents or amphoteric solvents) to perform wet mixing to form a mixed slurry. Because spherical alumina has good fluidity, it can have higher mixing uniformity and solid content (20-90vol%) in the mixing process, which can increase the production yield, so it is not necessary to use grinding balls, and to avoid product pollution from grinding balls This kind of product has higher purity than the product obtained by ball milling. The formed 0.2-10 μm spherical alumina can also be dry-mixed directly with carbon-containing raw materials (without any solvent) to form a mixture. Regardless of wet or dry mixing, the molar ratio of alumina to carbon is controlled from 1: 3.1 to 1:12. (B) The mixed slurry is then subjected to suction or centrifugal filtration to obtain a wet cake. The wet cake is then placed in an oven and dried at 60 to 160 ° C. for 1 to 96 hr to obtain a mixed powder. This is different from the spray drying commonly used at present, such a process can have a large manufacturing output, lower equipment investment, and cheap manufacturing costs. Mixtures can even omit this process, greatly reducing manufacturing costs. (D) Put the mixed powder or mixture into the crucible, and perform carbonization treatment in air or inert gas or vacuum atmosphere at a temperature of 300 ° C to 1200 ° C and a holding temperature of 1 to 96 hours. Then, in a furnace with a nitrogen-containing gas, perform a carbothermal reduction at a temperature of 1550 ° C to 1900 ° C and a holding temperature of 1 to 96 hours. Decarburization treatment to obtain spherical aluminum nitride with smooth surface.

上述步驟(A)中的球形氧化鋁，是透過氧化鋁粉高溫成形或鋁粉高溫熔融成形等製程成形而來的，球形氧化鋁球形度不小於70%。這種氧化鋁不添加助燒結劑(如：鋰的氧化物、釔的氧化物、鎂的氧化物、鈉的氧化物、鉀的氧化物、鈣的氧化物、硼的氧化物、矽的氧化物、鋰的碳酸鹽、釔的碳酸鹽、鎂的碳酸鹽、鈉的碳酸鹽、鉀的碳酸鹽、鈣的碳酸鹽、硼的碳酸鹽、矽的碳酸鹽中的一種或幾種混合物)。 The spherical alumina in the step (A) is formed through processes such as high-temperature alumina powder molding or high-temperature melt molding of aluminum powder, and the spherical alumina sphericity is not less than 70%. This alumina does not add sintering aids (such as: lithium oxide, yttrium oxide, magnesium oxide, sodium oxide, potassium oxide, calcium oxide, boron oxide, silicon oxide). One or more of lithium carbonate, lithium carbonate, yttrium carbonate, magnesium carbonate, sodium carbonate, potassium carbonate, calcium carbonate, boron carbonate, silicon carbonate).

上述步驟(A)中的球形氧化鋁的晶體結構，可以是單一的過渡相氧化鋁(如：γ相氧化鋁、δ相氧化鋁、θ相氧化鋁等)或是混合的過渡相氧化鋁或是單一的α相氧化鋁或是混合的過渡相氧化鋁和α相氧化鋁。 The crystal structure of the spherical alumina in the above step (A) may be a single transition phase alumina (such as γ-phase alumina, δ-phase alumina, θ-phase alumina, etc.) or a mixed transition-phase alumina or It is a single alpha phase alumina or a mixed transition phase and alpha phase alumina.

上述步驟(A)中的含碳原料，可以是碳黑、瀝青等含碳材料。 The carbon-containing raw material in the step (A) may be a carbon-containing material such as carbon black or pitch.

上述步驟(D)中的含氮氣體，可以是自由氨氣、氮氣、氮氣與CH4、氨氣與氮氣、氨氣與氫氣等組合性氣體。 The nitrogen-containing gas in the step (D) may be a combination gas such as free ammonia, nitrogen, nitrogen and CH4, ammonia and nitrogen, ammonia and hydrogen, and the like.

第一圖，為本發明一種微細球形氮化鋁粉的掃描式電子顯微鏡圖譜。 The first figure is a scanning electron microscope spectrum of a fine spherical aluminum nitride powder according to the present invention.

第二圖，為本發明一種微細球形氮化鋁粉的XRD圖譜。 The second figure is an XRD pattern of a fine spherical aluminum nitride powder according to the present invention.

實施例1：將102克、純度99%、平均粒徑250nm的球形氧化鋁(高溫融溶處理)，與150克碳黑乾式混合均勻後，放入BN坩堝中，在含有氮氣的氣氛下，進行1720℃持溫5小時的碳還原處理，最後在含氧氣氛的爐子中進行600℃，持溫5小時的脫碳處理，形成球形氮化鋁。請參閱第一圖，為本發明實施例碳熱還原後之奈米球形氮化鋁粉末掃描式電子顯微鏡圖譜，如圖所示，粉末呈現圓球狀，而且表面幾乎看不出晶界的存在，也沒有助燒結劑。第二圖，為本發明實施例碳熱還原後之微細球形氮化鋁粉末XRD結晶相圖譜，由圖可見製備所得的粉末呈現氮化鋁單一純相，證明已成功製備微細球形氮化鋁粉末。 Example 1: 102 g, alumina with a purity of 99%, and an average particle diameter of 250 nm (high temperature melt treatment) were dry-mixed with 150 g of carbon black, and then put into a BN crucible. Under an atmosphere containing nitrogen, Carbon reduction treatment was performed at a temperature of 1720 ° C for 5 hours, and finally, decarburization treatment was performed at 600 ° C for 5 hours in a furnace containing an oxygen atmosphere to form a spherical aluminum nitride. Please refer to the first figure, which is a scanning electron microscope image of the nano-spherical aluminum nitride powder after carbothermal reduction according to the embodiment of the present invention. As shown in the figure, the powder is spherical, and there are almost no grain boundaries on the surface. There is no sintering aid. The second figure is the XRD crystal phase spectrum of the fine spherical aluminum nitride powder after carbothermal reduction according to the example of the present invention. It can be seen from the figure that the powder obtained has a single pure phase of aluminum nitride, which proves that the fine spherical aluminum nitride powder has been successfully prepared. .

實施例2：將102克、純度99.9%、平均粒徑2um的球形氧化鋁，與180克碳黑一同放入溶劑中進行濕式混合，形成一混合漿料(固含量60vot%、無使用磨球)。之後將混合漿料，進行抽氣過濾，獲得濕餅。再將濕餅放入烘箱，進行150℃，烘乾24hr，獲得的混合粉體。將混合粉體放入石墨坩堝中，在通有含氮氣體的爐子中進行1600℃，持溫8小時的碳熱還原。最後在含氧氣氛的爐子中進行650℃，持溫6小時的脫碳處理，形成球形氮化鋁。 Example 2: 102 g of spherical alumina with a purity of 99.9% and an average particle size of 2 um were placed in a solvent together with 180 g of carbon black and wet-mixed to form a mixed slurry (solid content of 60 vot%, no milling used) ball). Thereafter, the mixed slurry was subjected to suction filtration to obtain a wet cake. The wet cake was placed in an oven and dried at 150 ° C. for 24 hours to obtain a mixed powder. The mixed powder was put into a graphite crucible and subjected to carbothermic reduction at 1600 ° C. for 8 hours at a temperature in a furnace passing a nitrogen-containing gas. Finally, in a furnace containing an oxygen atmosphere, decarburization treatment was performed at 650 ° C. for 6 hours to form a spherical aluminum nitride.

實施例3：將102克、純度99%、平均粒徑10um的球形氧化鋁(高溫融溶處理)，與200克碳黑乾式混合均勻後，放入BN坩堝中，在含有氮氣的氣氛下，進行1650℃持溫5小時的碳還原處理， 形成球形氮化鋁。最後在含氧氣氛的爐子中進行650℃，持溫4小時的脫碳處理，形成球形氮化鋁粉末。 Example 3: 102 g of spherical alumina with a purity of 99% and an average particle size of 10 um (high-temperature melt treatment) were dry-mixed with 200 g of carbon black, and then placed in a BN crucible under an atmosphere containing nitrogen. Carbon reduction treatment was performed at 1650 ° C for 5 hours to form spherical aluminum nitride. Finally, decarburization treatment was performed in a furnace containing an oxygen atmosphere at 650 ° C. and holding temperature for 4 hours to form a spherical aluminum nitride powder.

Claims (4)

一種製造微細球形氮化鋁粉末的方法，步驟包括：(A)提供一球形氧化鋁與含碳原料，一同放入溶劑中進行濕式混合，形成一混合漿料。因球形氧化鋁具有很好的流動性，在混合過程可以有較高的混合均勻性及固含量，可提高製造產量，也無需使用磨球，避免磨球對產品污染。球形氧化鋁與含碳原料，也可以直接進行乾式混合，形成一混合物。(B)之後將混合漿料進行過濾，獲得濕餅。再將濕餅烘乾，獲得混合粉體。(C)將混合粉體或混合物再放入坩堝中，在空氣或惰性氣體或真空氣氛中進行碳化處理。接著在通有含氮氣體的爐子中進行碳熱還原，最後在含氧氣氛的爐子中進行脫碳處理，以獲得平均粒徑0.25~10um的球形氮化鋁粉末。     A method for manufacturing fine spherical aluminum nitride powder, the steps include: (A) providing a spherical alumina and a carbonaceous raw material, and putting them into a solvent for wet mixing to form a mixed slurry. Because spherical alumina has good fluidity, it can have higher mixing uniformity and solid content during the mixing process, which can increase the production yield, and it does not need to use grinding balls to avoid product pollution by the grinding balls. The spherical alumina and the carbon-containing raw material may also be directly dry-mixed to form a mixture. (B) Then, the mixed slurry is filtered to obtain a wet cake. The wet cake is then dried to obtain a mixed powder. (C) Put the mixed powder or mixture into the crucible, and perform carbonization treatment in air or inert gas or vacuum atmosphere. Carbothermal reduction is then performed in a furnace that is vented with a nitrogen-containing gas, and finally a decarburization treatment is performed in a furnace containing an oxygen atmosphere to obtain a spherical aluminum nitride powder with an average particle size of 0.25-10um.     如申請專利範圍第一項所述之一種製造微細球形氮化鋁粉末的方法，其中該球形氧化鋁的晶體結構，係為單一的過渡相氧化鋁(如：γ相氧化鋁、δ相氧化鋁、θ相氧化鋁等)、混合的過渡相氧化鋁、單一的α相氧化鋁、混合的過渡相氧化鋁和α相氧化鋁所組成群組之一。     A method for manufacturing fine spherical aluminum nitride powder as described in the first item of the patent application scope, wherein the crystal structure of the spherical alumina is a single transition phase alumina (such as γ-phase alumina, δ-phase alumina). , Θ-phase alumina, etc.), mixed transition-phase alumina, single alpha-phase alumina, mixed transition-phase alumina, and alpha-phase alumina.     如申請專利範圍第一項所述之一種製造微細球形氮化鋁粉末的方法，其中該球形氧化鋁的成型方式，係為氧化鋁高溫成形、鋁粉熔融成形、氧化鋁高溫成形和鋁粉熔融成形所組成群組之一。     A method for manufacturing fine spherical aluminum nitride powder as described in the first item of the scope of patent application, wherein the spherical alumina is formed by alumina high temperature forming, aluminum powder melting forming, alumina high temperature forming, and aluminum powder melting. Forming one of the groups.     如申請專利範圍第一項所述之一種製造微細球形氮化鋁粉末的方法，其中，該步驟的(A)之混合方法係為不添加磨球的濕式混合或乾式混合。     A method for manufacturing a fine spherical aluminum nitride powder as described in the first item of the patent application range, wherein the mixing method of (A) in this step is wet mixing or dry mixing without adding grinding balls.