1363087 [·ι〇〇^·ΐ2^ 〇7B 六、發明說明： 【發明所屬之技術領域】 [0001]本發明係關於一種熱介面材料，尤其係〆種導熱膏製備 方法。 【先前技術】 [0002]隨著積體電路之密集及微型化程度越來越咼，電子元件 變的越來越小且以高速度運行，電子元件在其工作溫度 範圍内才能確保具有良好的工作性能及穩定性’因此’ 其對散熱之要求越來越高。為將熱量散發出去’於電子 ^ 元件表面安裝一散熱裝置成為業内普遍之做法，利用散 熱裝置材料之高熱傳導性，將熱量迅速向外部散發。惟 ’散熱裝置與電子元件表面存在一定間隙’使散熱裝置 與電子元件未能緊密接觸，此係散熱裝置散熱之一大缺 陷》針對散熱裝置與電子元件表面之接觸問題，業内之 做法一般係於電子元件與散熱裝置之間添加一熱介面材 料，以提高電子元件與散熱裝置之間之熱傳導效率。 ^ [〇〇〇3]通常，用於發熱電子元件上以幫助散熱之熱介面材料有 導熱膏、導熱薄片、散熱簿片等。其甲’導熱膏係於液 態高分子基體材料中添加陶瓷粉體、石墨粉或金屬粉， 以做成液態或者半固態之導齡，該等粉體之主要作用 為擔任熱傳遞之主趙、填補電子元件表面的凹凸處。惟 ，該等粉體之粒徑較大，不能有效地填補電子元件表面 的不平整。 圆為有效地填補電子元件之心處，改善導料之性能， 提高其導熱係數’先前技術中利用填充奈米級高導熱'吐 094128479 表單编號A0101 第3頁/共12頁 1003452846-0 1363087 100年.12月0>日梭正替換頁 [0005] [0006] [0007] [0008] [0009] [0010] [0011] [0012] [0013] 能材料，如奈米銀粉、鑽石粉末以及奈米碳球等具有優 良導熱性能之材料。雖然，上述先前技術中所提供之導 熱膏導熱性能有較大提升，惟，與預期效果仍有一定差 距。其原因係當於聚合物基體材料中添加所述奈米級高 導熱性能材料時，由於高導熱性能材料尺寸為奈米級， 比表面積大，表面能量高，使得奈米粉體在基體材料中 會傾向縮小表面積以趨於穩定，故易於聚集成大粒徑之 粒子，導致電子元件與導熱膏很難充分接觸，從而導致 導熱膏之熱阻增加，影響導熱膏之導熱性能。 有鑑於此，提供一種熱阻小、導熱性能優異之導熱膏及 其製備方法實為必要。 【發明内容】 以下將通過實施例說明一種熱阻小、導熱性能優異之導 熱膏製備方法。 一種導熱膏之製備方法，該方法包括以下步驟： 提供一硝酸銀之水溶液； 將導熱粉體浸泡於上述水溶液之中，使導熱粉體表面附 著硝酸銀； 將導熱粉體從水溶液中分離； 熱處理附著有硝酸銀之導熱粉體，使硝酸銀分解，銀粒 子附著於導熱粉體表面； 將導熱粉體與基體混合製成導熱膏。 該硝酸銀水溶液之濃度為1 4〜0. lmol/L，導熱粉1363087 [·ι〇〇^·ΐ2^ 〇7B VI. Description of the Invention: [Technical Field of the Invention] [0001] The present invention relates to a thermal interface material, and more particularly to a method for preparing a thermal conductive paste. [Prior Art] [0002] With the increasing density and miniaturization of integrated circuits, electronic components are becoming smaller and smaller and operating at high speeds, and electronic components can be ensured within their operating temperature range. Work performance and stability 'so' its requirements for heat dissipation are getting higher and higher. It is a common practice in the industry to dissipate heat to dissipate a heat sink on the surface of the electronic component. The heat of the material of the heat sink is used to rapidly dissipate heat to the outside. However, 'there is a certain gap between the heat sink and the surface of the electronic component', so that the heat sink is not in close contact with the electronic components. This is one of the major defects in heat dissipation of the heat sink. The practice of the heat sink is in contact with the surface of the electronic component. A thermal interface material is added between the electronic component and the heat sink to improve the heat transfer efficiency between the electronic component and the heat sink. ^ [〇〇〇3] Generally, the thermal interface materials used for heat-dissipating electronic components to help dissipate heat are thermal pastes, thermal sheets, heat sinks, and the like. Its 'thermal paste' is added to the liquid polymer matrix material to add ceramic powder, graphite powder or metal powder to make the liquid or semi-solid lead age. The main function of these powders is to serve as the main heat transfer. Fill the bumps on the surface of the electronic components. However, these powders have a large particle size and cannot effectively fill the unevenness of the surface of the electronic component. The circle effectively fills the heart of the electronic components, improves the performance of the guide material, and improves its thermal conductivity. 'Previously used to fill the nanometer high thermal conductivity' 094124479 Form No. A0101 Page 3 / Total 12 Page 1003452846-0 1363087 [0013] [0013] [0013] [0013] [0013] [0013] [0013] Energy materials, such as nano silver powder, diamond powder, and A material with excellent thermal conductivity such as nano carbon spheres. Although the thermal conductivity of the thermal paste provided in the above prior art is greatly improved, there is still a certain difference from the expected effect. The reason is that when the nano-high thermal conductivity material is added to the polymer matrix material, since the material having a high thermal conductivity is nanometer, the specific surface area is large, and the surface energy is high, the nano powder is in the matrix material. The tendency to reduce the surface area tends to be stable, so that it is easy to aggregate into particles of large particle size, which makes it difficult for the electronic component to be in sufficient contact with the thermal conductive paste, thereby causing an increase in the thermal resistance of the thermal conductive paste and affecting the thermal conductivity of the thermal conductive paste. In view of the above, it is necessary to provide a thermal conductive paste having a small thermal resistance and excellent thermal conductivity and a method for preparing the same. SUMMARY OF THE INVENTION Hereinafter, a method for preparing a thermal conductive paste having a small thermal resistance and excellent thermal conductivity will be described by way of examples. A method for preparing a thermal conductive paste, the method comprising the steps of: providing an aqueous solution of silver nitrate; immersing the thermal conductive powder in the aqueous solution to adhere silver nitrate to the surface of the thermal conductive powder; separating the thermally conductive powder from the aqueous solution; The thermal conductive powder of silver nitrate decomposes silver nitrate, and the silver particles adhere to the surface of the thermal conductive powder; the thermal conductive powder is mixed with the substrate to form a thermal conductive paste. The concentration of the silver nitrate aqueous solution is 1 4~0. lmol / L, thermal powder
094128479 表單編號A0101 第4頁/共12頁 1003452846-0 1363087 100年.12月0·7日核正替換頁 體與硝酸銀溶液之重量比值為1:1 000 ~ 3:10。 [0014] 相較於先前技術，本實施例之導熱膏的導熱粉體表面具 有高導熱的銀粒子，該銀粒子可以填補電子元件表面的 不平整，將凹凸處的空氣排出，因此可降低導熱膏與電 子元件之間的接觸熱阻，具有優異的導熱性能。 【實施方式】 [0015] 如第一圖所示，其為本發明第一實施例所提供之導熱膏 10，該導熱膏10包括基體12以及分散於該基體12中的導 熱粉體14。其中，該導熱粉體14表面均勻分佈有銀粒子 140 ° [0016] 該導熱粉體14之粒徑大小為1〜100微米，銀粒子140之粒 徑在1〜100奈米之間，該導熱粉體14與基體12之重量比 值為1:1〜1:20。 [0017] 該基體12可選自高分子材料，如聚乙酸乙烯、聚乙烯、 矽油、丙烯酸脂、聚丙烯、環氧樹脂、聚甲醛、聚乙烯 醇、烯烴樹脂中之一或者幾種組成的混合物。 [0018] 該導熱粉體14可選自具有良好導熱性能之材料，如銅、 鎳、氧化鋁、鎳化綳、碳化矽、碳化鋁、二氧化矽、氧 化辞、二氧化鈦中之一或者幾種組成的混合物。 [0019] 如第二圖所示，使用時，將導熱膏10塗佈於電子元件20 與散熱裝置40之間，導熱粉體14表面的銀粒子140可以填 補電子元件20表面的凹陷22，減少導熱膏10與電子元件 〆 20之間的接觸熱阻，使導熱膏10具有優異的導熱性能。 [0020] 請參閱第三圖，其為本發明第二實施例導熱膏製備方法 094128479 表單编號 Α0101 第 5 頁/共 12 頁 1003452846-0 1363087 [0021] [0022] [0023] [0024] [0025] [0026] [0027] 100年.12月07日梭正替換頁 之流程圖，該方法包括以下步驟： 步驟一，提供一硝睃銀之水溶液； 步驟二，將導熱粉體浸泡於上述水溶液之中，使導熱粉 體表面附著硝酸銀； 步驟三，將導熱粉體從水溶液中分離； 步驟四，熱處理附著有硝酸銀之導熱粉體，使硝酸銀分 解，銀粒子附著於導熱粉體表面；094128479 Form No. A0101 Page 4 of 12 1003452846-0 1363087 100 years. December 0. 7 The replacement ratio between the weight of the body and the silver nitrate solution is 1:1 000 ~ 3:10. [0014] Compared with the prior art, the surface of the thermally conductive powder of the thermal paste of the present embodiment has high thermal conductivity silver particles, which can fill the unevenness of the surface of the electronic component and discharge the air at the concavities and convexities, thereby reducing heat conduction. The thermal resistance of the contact between the paste and the electronic component has excellent thermal conductivity. [Embodiment] As shown in the first figure, the thermal conductive paste 10 according to the first embodiment of the present invention includes a substrate 12 and a heat conductive powder 14 dispersed in the substrate 12. The surface of the thermally conductive powder 14 is uniformly distributed with silver particles 140 ° [0016] The thermal conductive powder 14 has a particle size of 1 to 100 μm, and the silver particles 140 have a particle diameter of 1 to 100 nm. The weight ratio of the powder 14 to the substrate 12 is 1:1 to 1:20. [0017] The substrate 12 may be selected from a polymer material, such as one or several of polyvinyl acetate, polyethylene, eucalyptus oil, acrylate, polypropylene, epoxy resin, polyoxymethylene, polyvinyl alcohol, olefin resin. mixture. [0018] The thermally conductive powder 14 may be selected from materials having good thermal conductivity, such as one or more of copper, nickel, aluminum oxide, lanthanum nickel, niobium carbide, aluminum carbide, hafnium oxide, oxidized rhodium, titanium dioxide. a mixture of components. [0019] As shown in the second figure, in use, the thermal paste 10 is applied between the electronic component 20 and the heat sink 40, and the silver particles 140 on the surface of the thermal powder 14 can fill the recess 22 on the surface of the electronic component 20, reducing The thermal resistance of contact between the thermal paste 10 and the electronic component 20 makes the thermal paste 10 have excellent thermal conductivity. Please refer to the third figure, which is a method for preparing a thermal paste according to a second embodiment of the present invention. 094128479 Form No. 1010101 Page 5 of 12 1003452846-0 1363087 [0021] [0023] [0024] [0024] [0027] [0027] [0027] 100 years. December 07, the shuttle is replacing the flow chart of the page, the method comprises the following steps: Step one, providing an aqueous solution of nitronium silver; Step two, soaking the thermal powder in the above In the aqueous solution, silver nitrate is adhered to the surface of the heat conductive powder; Step 3: separating the heat conductive powder from the aqueous solution; Step 4, heat-treating the heat conductive powder to which the silver nitrate is adhered to decompose the silver nitrate, and the silver particles adhere to the surface of the heat conductive powder;
步驟五，將導熱粉體與基體混合製成導熱膏。 I 下面結合具體實施例對各步驟進行詳細說明。 步驟一係提供一硝酸銀之水溶液。該硝酸銀水溶液之濃 度可為 1χ·10 4~0.1mol/L。 [0028] 步驟二係將導熱粉體浸泡於上述水溶液之中，使導熱粉 體表面附著硝酸銀。導熱粉體浸泡於硝酸銀溶液中一定 時間，如24小時，導熱粉體表面會附著有硝酸銀溶液。 導熱粉體與硝酸銀溶液之重量比值可為1 : 1〇〇〇~3:10。 [0029] 該導熱粉體可選自具有良好導熱性能之材料，如銅、鎳 、氧化鋁、鎳化綳、碳化矽、碳化鋁、二氧化矽、氧化 鋅、二氧化鈦中之一或者幾種組成的混合物。優選地， 導熱材料為粉體或者微粒結構，其粒徑為1~1〇〇微米。 [0030] 步驟三係將導熱粉體從水溶液中分離。導熱粉體於硝酸 銀溶液中浸泡24小時候後，將其從硝酸銀溶液中分離， 分離出的導熱粉體表面會殘留有硝酸銀溶液。該分離方 094128479 表單编號 A0101 第 6 頁/共 12 頁 1003452846-0 1363087 100·年.12月0>日梭正^頁 法可採用離心分離、過濾等適合固體、液體之分離方式 〇 [0031] 步驟四係熱處理附著有硝酸銀之導熱粉體，使硝酸銀分 解，銀粒子附著於導熱粉體表面。於450〜500°C之環境中 煅燒分離出的導熱粉體，由於硝酸銀的熱分解溫度為443 °C，在高溫下其可分解產生銀、一氧化氮及二氧化氮氣 體，分解產生的氣體揮發出去，而銀粒子則均勻沈積於 導熱粉體表面。 # [0032] 4 步驟五係將導熱粉體與基體混合製成導熱膏。將表面沈 積有銀粒子之導熱粉體與基體以重量1 :卜1 : 20之比例放 入混合器混合，該混合器可為三滾筒混合器、行星式混 合器等。優選地，本實施例使用行星式混合器，對混有 導熱粉體及基體之混合物進行混合，使導熱粉體均勻分 散於基體中。 [0033] 採用該方法製備之導熱膏，大粒徑之導熱粉體表面具有 微小的銀粒子，該銀粒子可以填補電子元件表面的不平 整，將凹凸處的空氣排出，且銀粒子本身具有良好之導 熱性能，因此可降低導熱膏與電子元件之間的接觸熱阻 ，使得導熱膏具有優異的導熱性能。 [0034] 綜上所述，本發明符合發明專利要件，爰依法提出專利 申請。惟，以上所述者僅為本發明之較佳實施例，舉凡 熟悉本發明技藝之人士，在援依本發明精神所作之等效 修飾或變化，皆應包含於以下之申請專利範圍内。 【圖式簡單說明】 094128479 表單编號A0101 第7頁/共12頁 1003452846-0 1363087 .100年.12月07日梭正替換頁 [0035] 第一圖係本發明第一實施例導熱膏之示意圖。 [0036] 第二圖係本發明使用狀態參考圖。 [0037] 第三圖係本發明第二實施例導熱膏製備方法之流程圖。 【主要元件符號說明】 [0038] 導熱膏：1〇 [0039] 基體：12 [0040] 導熱粉體：14 [0041] 電子元件：20 ^ [0042] 凹陷：2 2 [0043] 散熱裝置：40 [0044] 銀粒子：140 094128479 表單编號A0101 第8頁/共12頁 1003452846-0In step 5, the thermal conductive powder is mixed with the substrate to form a thermal paste. I. Each step will be described in detail below in conjunction with specific embodiments. In the first step, an aqueous solution of silver nitrate is provided. The concentration of the aqueous silver nitrate solution may be from 1 χ·10 4 to 0.1 mol/L. [0028] In the second step, the heat conductive powder is immersed in the aqueous solution to adhere silver nitrate to the surface of the heat conductive powder. The thermal conductive powder is immersed in the silver nitrate solution for a certain period of time, such as 24 hours, and a silver nitrate solution adheres to the surface of the thermal conductive powder. The weight ratio of the thermally conductive powder to the silver nitrate solution may be 1: 1 〇〇〇 to 3:10. [0029] The thermally conductive powder may be selected from materials having good thermal conductivity, such as one or several of copper, nickel, aluminum oxide, lanthanum nickel carbide, tantalum carbide, aluminum carbide, cerium oxide, zinc oxide, and titanium dioxide. mixture. Preferably, the heat conductive material is a powder or a particulate structure having a particle diameter of 1 to 1 micron. [0030] Step 3 is to separate the thermally conductive powder from the aqueous solution. After the thermal conductive powder is immersed in the silver nitrate solution for 24 hours, it is separated from the silver nitrate solution, and a silver nitrate solution remains on the surface of the thermally conductive powder separated. The separation side 094128479 Form No. A0101 Page 6 / Total 12 Page 1003452846-0 1363087 100·year. December 0> The Japanese shuttle method can be separated by centrifugal separation, filtration, etc. Suitable for solid and liquid separation 〇 [0031 Step 4: heat-treating the thermal conductive powder to which silver nitrate is adhered to decompose the silver nitrate, and the silver particles adhere to the surface of the thermally conductive powder. Calcined and separated thermally conductive powder in an environment of 450 to 500 ° C. Since the thermal decomposition temperature of silver nitrate is 443 ° C, it can be decomposed to produce silver, nitrogen monoxide and nitrogen dioxide gas at high temperature, and the gas generated by decomposition It evaporates and the silver particles are uniformly deposited on the surface of the thermally conductive powder. # [0032] 4 Step 5: The thermal conductive powder is mixed with the substrate to form a thermal paste. The thermally conductive powder on which the silver particles are deposited on the surface and the substrate are mixed in a mixer at a weight ratio of 1:20, which may be a three-roller mixer, a planetary mixer or the like. Preferably, this embodiment uses a planetary mixer to mix a mixture of the thermally conductive powder and the matrix to uniformly disperse the thermally conductive powder in the matrix. [0033] The thermal conductive paste prepared by the method, the surface of the large-diameter thermal conductive powder has minute silver particles, which can fill the unevenness of the surface of the electronic component, discharge the air at the concave and convex portions, and the silver particles themselves have good The thermal conductivity can reduce the thermal contact resistance between the thermal paste and the electronic component, so that the thermal paste has excellent thermal conductivity. [0034] In summary, the present invention complies with the requirements of the invention patent, and submits a patent application according to law. It is to be understood that the above-mentioned preferred embodiments of the present invention are intended to be included within the scope of the appended claims. [Simple description of the drawing] 094128479 Form No. A0101 Page 7 / Total 12 pages 1003452846-0 1363087 .100 years. December 07 Shuttle replacement page [0035] The first figure is the first embodiment of the present invention schematic diagram. [0036] The second figure is a reference state diagram of the use of the present invention. [0037] The third figure is a flow chart of a method for preparing a thermal paste according to a second embodiment of the present invention. [Main component symbol description] [0038] Thermal paste: 1〇 [0039] Base: 12 [0040] Thermal powder: 14 [0041] Electronic component: 20 ^ [0042] Depression: 2 2 [0043] Heat sink: 40 [0044] Silver Particles: 140 094128479 Form No. A0101 Page 8/Total 12 Page 1003452846-0