201043687 六、發明說明： 【發明所屬之技術領域】 [0001]本發明涉及一種熱介面材料，具該熱介面材料之電子裝 置及該電子裝置之製備方法。 【先前技術】 〇 [0002]近年來，隨著半導體器件集成工藝之快速發展，半導體 器件之集成化程度越來越高，器件體積變得越來越小， 然’半導體器件體積之減小也提高了其對散熱之要求。 為滿足該半導體器件對散熱之需要，風扇散熱、水冷輔 助散熱及熱管散熱等各種散熱方式被廣泛運用，並取得 一定之散熱效果。但因散熱裝置與熱源(半導體集成器件 ，如CPU)之接觸介面不平整，實際接觸面積—般不到總 面積之2%，因此從根本上影響熱源向散熱裝置傳遞熱量 之效果。為了增加熱源與散熱裝置兩個介面之間之接觸 面積，通常於熱源與散熱裝置之間填加一f熱係數較高 之熱介面材料（Thermal Interface Materials)，用 於填補熱源與散熱裝置接觸時產生之微空隙及表面凹凸 不平之孔洞，增加熱源與散熱裝置兩個介面之接觸面積 ’減少熱傳遞之阻抗’改善熱源與散熱裝置間之熱傳遞 效果。 [0003] 傳統之熱介面材料係通過於如矽膠、橡膠之類之柔性義 體中添加一些具有優異導熱性能之導熱顆粒如氣化石夕 銀或其他金屬等來形成複合材料。奈米碳管沿其料向方 向具有極高之導熱係數，使其成為最具潛力之熱介面材 料之一。2004年9月16日申請並於2005年6月2日八 A開之 098118138 表單編號Λ0101 第3頁/共19頁 〇982〇3〇786~〇 201043687 第2005/01 1 6336 A1號美國專利申請公開了一種熱介面 材料，該熱介面材料將複數奈米碳管均勻分散於一柔性 基體中，該複數奈米碳管相互搭接於熱源與散熱裝置之 間形成複數導熱通道。 [0004] 奈米碳管軸向方向之導熱係數較高，但其徑向方向之導 熱係數極低，因此，由該複數奈米碳管形成之導熱通道 中，其熱傳遞路徑之長度取決於相互搭接成該一導熱通 道之所有奈米碳管之軸向長度之和。而該複數奈米碳管 於柔性基體中之方向難以控制，該奈米碳管軸向方向與 熱傳遞方向一致之概率很小，因此，需要較多之奈米碳 管搭接才能形成一導熱通道，從而造成該熱介面材料之 傳熱路徑較長；且，由於奈米碳管之尺寸較小，相互搭 接之兩個奈米碳管之間之熱阻較大，無法有效利用奈米 碳管之導熱性能。因此，該熱介面材料之導熱性能還有 待進一步提高。 【發明内容】 [0005] 有鑒於此，提供一種導熱性能更佳之熱介面材料，具該 熱介面材料之電子裝置及該電子裝置之製備方法實為必 要。 [0006] 一種熱介面材料，其包括一柔性基體及分佈於該柔性基 體中之複數複合導熱顆粒。該複合導熱顆粒包括一金屬 顆粒及至少一奈米碳管複合於該金屬顆粒中。 [0007] 一種熱介面材料，其包括一柔性基體及分佈於該柔性基 體中之複數金屬顆粒。至少部分金屬顆粒中每一第一金 屬顆粒進一步包括至少一奈米碳管複合於該第一金屬顆 098118138 表單編號A0101 第4頁/共19頁 0982030786-0 201043687 [0008] [0009] Ο [0010]❹ 098118138 粒中形成複數複合導熱顆粒。 一種電子裝置，其包括一熱源及一設置於該熱源表面之 熱介面材料。該熱介面材料包括一柔性基體及分佈於該 柔性基體中之複數第一金屬顆粒。至少部分該第一金屬 顆粒中每一第一金屬顆粒進一步包括至少一奈米碳管複 合於該第一金屬顆粒中形成複數複合導熱顆粒。 一種電子裝置之製備方法，其包括如下步驟：提供一熱 介面材料預製體及一熱源，該熱源具有一使該熱源不至 於過熱損壞之保護溫度，該熱介面材料預製體包括一柔 性基體、填充於該柔性基體中之複數第二金屬顆粒及複 數奈米碳管，該第二金屬顆粒粒徑小於100奈米，且該第 二金屬顆粒於該粒徑下之熔融溫度小於該保護溫度；將 該熱介面材料預製體設置於該熱源表面；加熱該熱介面 材料預製體，使該第二金屬顆粒熔融團聚；冷卻該熱介 面材料預製體，形成熱介面材料於熱源表面。 相較於先前技術，該熱介面材料中之奈米碳管複合於第 一金屬顆粒中形成複合導熱顆粒。由於該複合導熱顆粒 之熱傳遞方向無方向性限制，由該複數複合導熱顆粒相 互搭接而形成之導熱通道，具有較短之熱傳遞路徑；且 ，由於複合導熱顆粒具有較大之粒徑，相互搭接之複合 導熱顆粒之間之熱阻較小。因此，該熱介面材料有效利 用了奈米碳管優異之導熱性能，具有較好之導熱性能。 【實施方式】 下面將結合附圖對本發明實施例之熱介面材料，具該熱 介面材料之電子裝置及該電子裝置之製備方法作進一步 表單編號Α0101 第5頁/共19頁 0982030786-0 [0011] 201043687 詳細說明。 [0012] 請參閱圖1，為本發明實施例提供之電子裝置1〇〇，其包 括一熱源10、一散熱裝置20及一熱介面材料3〇，該熱介 面材料30設置於該熱源1〇及散熱裝置2〇之間，用於將該 熱源10產生之熱量傳遞給該散熱裝置2〇。 [0013] 該熱源ίο可以係半導體集成器件，也可以係IC電路，電 阻或其他發熱元件。該熱源1〇具有一使該熱源1〇不至於 過熱損壞之保護溫度T1。可以理解，當該熱源10之溫度 超過T1時，該熱源10會由於過熱而損壞，即T1為熱源1〇 不至於損壞之最大容忍溫度。優選地，該保護溫度T 1小 於350 C。在本實施例中，該熱源1Q為CPU，其保護溫度 T1 為 120〇C。 … [0014] 該散熱裝置20用於將該熱源10產生之熱量快速導出，使 熱源10不產生熱積累。 [0015] 該熱介面材料30於設置於該熱源10與散熱裝置2〇之間。 請參閱圖2，該熱介面材料30包括一柔性基體31及填充於 該柔性基體31中之複數複合導熱顆粒32。 [0016] 該柔性基體31之熔融溫度大於該保護溫度T1，使該熱介 面材料30於工作時能夠保持固定之形狀，不從該電子裝 置100溢出。在本實施例中，該柔性基體31為熱塑性樹脂 與熱固性聚合物所組成之混合體。其中，該熱塑性樹脂 可為環氧樹脂系列，酚醛樹脂系列，聚醯胺樹脂系列中 之任意一種；該熱固性聚合物材料可為丁苯橡膠系列， 溶膠凝膠系列，石夕膠系列中之任意一種。在本實施例中 098118138 表單編號A0101 第6頁/共19頁 0982030786-0 201043687 ，該柔性基體31為酚醛樹脂系列與溶膠凝膠系列所組成 之混合物。 [0017] Ο 該複數複合導熱顆粒32均勻分散於該柔性基體31中，該 複數複合導熱顆粒32在該熱介面材料30中之質量百分含 量為15%〜95% ’該複合導熱顆粒32之粒徑大於1〇〇奈米且 於該粒徑之熔融溫度大於該保護溫度^。該複合導熱顆 粒包括一第一金屬顆粒321及至少一奈米碳管322複合於 該第一金屬顆粒321中。該第一金屬顆粒321於該熱介面 材料30中之質量百分含量為15%〜95%，該第一金屬顆粒 321之材料可為銀、銅、錫鉛合金或鋁該奈米碳管322 於該熱介面材料30中之質量百分含量為1%~25%，其包括 單壁奈米碳管、雙壁奈米碳:管或多壁奈米碳管，進一步 地，為了增強該奈米碳管322對第一金屬顆粒321之親和 力’可對該奈米碳管322之表面進行修飾，如通過化學鍍 等方法於該奈米碳管322之表面鍍上金屬或合金。201043687 VI. Description of the Invention: [Technical Field of the Invention] [0001] The present invention relates to a thermal interface material, an electronic device having the same, and a method of manufacturing the electronic device. [Prior Art] 〇[0002] In recent years, with the rapid development of semiconductor device integration processes, the degree of integration of semiconductor devices has become higher and higher, and the device size has become smaller and smaller, but the volume of semiconductor devices has also decreased. Increased its requirements for heat dissipation. In order to meet the heat dissipation requirements of the semiconductor device, various heat dissipation methods such as fan heat dissipation, water cooling auxiliary heat dissipation, and heat pipe heat dissipation are widely used, and a certain heat dissipation effect is obtained. However, since the contact interface between the heat sink and the heat source (semiconductor integrated device such as CPU) is not flat, the actual contact area is generally less than 2% of the total area, thus fundamentally affecting the effect of heat transfer from the heat source to the heat sink. In order to increase the contact area between the heat source and the heat sink, a thermal interface material (Thermal Interface Materials) with a high thermal coefficient is usually added between the heat source and the heat sink to fill the heat source and the heat sink. The resulting micro-voids and uneven holes on the surface increase the contact area between the heat source and the heat sink device to reduce the heat transfer impedance, improving the heat transfer between the heat source and the heat sink. [0003] A conventional thermal interface material is formed by adding some thermally conductive particles having excellent thermal conductivity such as gasification silver silver or other metals to a flexible body such as silicone rubber or rubber. The carbon nanotubes have a very high thermal conductivity along their material direction, making them one of the most promising thermal interface materials. Application No. 098118138, filed on September 16, 2004, and opened on June 2, 2005. Form No. 1010101 Page 3 of 19 〇982〇3〇786~〇201043687 No. 2005/01 1 6336 A1 US Patent Application Disclosed is a thermal interface material that uniformly disperses a plurality of carbon nanotubes in a flexible substrate, and the plurality of carbon nanotubes overlap each other to form a plurality of heat conduction channels between the heat source and the heat sink. [0004] The thermal conductivity of the carbon nanotube in the axial direction is relatively high, but the thermal conductivity in the radial direction is extremely low. Therefore, the length of the heat transfer path in the heat conduction channel formed by the plurality of carbon nanotubes depends on The sum of the axial lengths of all the carbon nanotubes that overlap each other into the one heat conducting channel. The direction of the plurality of carbon nanotubes in the flexible substrate is difficult to control, and the probability that the axial direction of the carbon nanotubes coincides with the heat transfer direction is small. Therefore, more carbon nanotubes are required to form a heat conduction. Channel, which causes the heat transfer path of the thermal interface material to be long; and, because of the small size of the carbon nanotubes, the thermal resistance between the two carbon nanotubes overlapping each other is large, and the nanometer cannot be effectively utilized. The thermal conductivity of carbon tubes. Therefore, the thermal conductivity of the thermal interface material needs to be further improved. SUMMARY OF THE INVENTION [0005] In view of the above, a thermal interface material having better thermal conductivity is provided, and an electronic device having the thermal interface material and a method of preparing the electronic device are essential. A thermal interface material comprising a flexible substrate and a plurality of composite thermally conductive particles distributed in the flexible substrate. The composite thermally conductive particles comprise a metal particle and at least one carbon nanotube is composited in the metal particle. A thermal interface material comprising a flexible substrate and a plurality of metal particles distributed in the flexible substrate. Each of the at least a portion of the metal particles further comprises at least one carbon nanotube composited to the first metal 098118138. Form No. A0101 Page 4 / 19 pages 0992030786-0 201043687 [0008] [0009] Ο [0010 ] 098 098118138 A complex composite thermally conductive particle is formed in the granule. An electronic device includes a heat source and a thermal interface material disposed on a surface of the heat source. The thermal interface material includes a flexible substrate and a plurality of first metal particles distributed in the flexible substrate. At least a portion of each of the first metal particles further includes at least one carbon nanotube coupled to the first metal particles to form a plurality of composite thermally conductive particles. A method of fabricating an electronic device, comprising the steps of: providing a thermal interface material preform and a heat source having a protection temperature that prevents the heat source from being damaged by overheating, the thermal interface material preform comprising a flexible substrate, filling a plurality of second metal particles and a plurality of carbon nanotubes in the flexible substrate, the second metal particles having a particle size of less than 100 nanometers, and a melting temperature of the second metal particles at the particle diameter is less than the protective temperature; The thermal interface material preform is disposed on the heat source surface; the thermal interface material preform is heated to melt agglomerate the second metal particles; and the thermal interface material preform is cooled to form a thermal interface material on the heat source surface. Compared to the prior art, the carbon nanotubes in the thermal interface material are combined with the first metal particles to form composite thermally conductive particles. Since the heat transfer direction of the composite heat conductive particles is not directional, the heat conduction channel formed by the overlapping of the plurality of composite heat conductive particles has a short heat transfer path; and, since the composite heat conductive particles have a large particle diameter, The thermal resistance between the composite thermally conductive particles that overlap each other is small. Therefore, the thermal interface material effectively utilizes the excellent thermal conductivity of the carbon nanotubes and has good thermal conductivity. [Embodiment] Hereinafter, a thermal interface material according to an embodiment of the present invention, an electronic device having the same, and a preparation method of the electronic device will be further described in conjunction with the accompanying drawings. 表单0101 Page 5 of 19 0982030786-0 [0011 ] 201043687 Detailed description. 1 is an electronic device 1A according to an embodiment of the invention, comprising a heat source 10, a heat sink 20 and a thermal interface material 3, wherein the heat interface material 30 is disposed on the heat source 1 And the heat sink 2 , is used to transfer the heat generated by the heat source 10 to the heat sink 2 . [0013] The heat source ίο may be a semiconductor integrated device or an IC circuit, a resistor or other heat generating component. The heat source 1 has a protection temperature T1 that prevents the heat source 1 from being damaged by overheating. It can be understood that when the temperature of the heat source 10 exceeds T1, the heat source 10 is damaged by overheating, that is, T1 is the maximum tolerated temperature at which the heat source 1〇 is not damaged. Preferably, the protection temperature T 1 is less than 350 C. In this embodiment, the heat source 1Q is a CPU having a protection temperature T1 of 120 〇C. [0014] The heat sink 20 is used to quickly derive the heat generated by the heat source 10 so that the heat source 10 does not generate heat accumulation. [0015] The thermal interface material 30 is disposed between the heat source 10 and the heat sink 2 . Referring to FIG. 2, the thermal interface material 30 includes a flexible substrate 31 and a plurality of composite thermally conductive particles 32 filled in the flexible substrate 31. [0016] The melting temperature of the flexible substrate 31 is greater than the protection temperature T1, so that the thermal interface material 30 can maintain a fixed shape during operation without overflowing from the electronic device 100. In the present embodiment, the flexible substrate 31 is a mixture of a thermoplastic resin and a thermosetting polymer. The thermoplastic resin may be any one of an epoxy resin series, a phenolic resin series and a polyamidamide resin series; the thermosetting polymer material may be any of a styrene-butadiene rubber series, a sol-gel series, and a Shiyue rubber series. One. In the present embodiment, 098118138 Form No. A0101, Page 6 of 19, 0982030786-0 201043687, the flexible substrate 31 is a mixture of a phenolic resin series and a sol gel series. [0017] 复 the plurality of composite thermally conductive particles 32 are uniformly dispersed in the flexible substrate 31, and the mass percentage of the plurality of composite thermally conductive particles 32 in the thermal interface material 30 is 15% to 95%. The particle size is greater than 1 nanometer and the melting temperature of the particle size is greater than the protection temperature. The composite thermally conductive particles include a first metal particle 321 and at least one carbon nanotube 322 composited in the first metal particle 321 . The mass percentage of the first metal particles 321 in the thermal interface material 30 is 15% to 95%, and the material of the first metal particles 321 may be silver, copper, tin-lead alloy or aluminum. The mass percentage of the thermal interface material 30 is 1% to 25%, and includes a single-walled carbon nanotube, a double-walled nanocarbon: tube or a multi-walled carbon nanotube, and further, in order to enhance the The affinity of the carbon nanotube 322 to the first metal particle 321 can modify the surface of the carbon nanotube 322 by plating a metal or an alloy on the surface of the carbon nanotube 322 by electroless plating or the like.
[0018] G 該複合導熱顆粒32通過該第一金屬顆粒321複合至少一奈 米碳管322而形成，具體地，磚奈米碳管322分散於該第 一金屬顆粒321中。該複合導熱顆粒32有效利用了奈米碳 管322優異之導熱性能，且大大降低分散於同一第一金屬 顆粒321中之複數奈米碳管322之間之介面熱阻。由於該 複合導熱顆粒32之熱傳遞方向無方向性限制，由該複數 複合導熱顆粒32相互搭接而形成之導熱通道，具有較短 之熱傳遞路徑；且，由於複合導熱顆粒32具有較大之粒 徑，相互搭接之複合導熱顆粒32之間之熱阻較小。因此 ，該熱介面材料100有效利用了奈米碳管322優異之導熱 098118138 表單编號A0101 0982030786-0 201043687 性能，具有較好之導熱性能。 [0019] 在該熱介面材料30中，還可包括複數未複合該奈米碳管 322之第一金屬顆粒321，該第一金屬顆粒321之粒徑大 於100奈米。亦即，該柔性基體31中之導熱粒子包括複合 導熱顆粒32與第一金屬顆粒321兩種。此時，該導熱通道 由該複數複合導熱顆粒32及複數第一金屬顆粒321相互搭 接而形成。可以理解，當該熱介面材料30還包括複數未 複合該奈米碳管322之第一金屬顆粒321時，該熱介面材 料30也可通過如下方式描述，該熱介面材料30包括柔性 基體31及分散於該柔丨生基瞪31中之複數第一金屬顆粒321 。其中一部分第一金屬顆粒321與奈米碳管322複合形成 複數複合導熱顆粒32。 [0020] 請參閱圖3及圖4，該電子裝置100之製備方法包括如下步 驟。 [0021] 步驟S101，提供一熱介面材料預製體及一熱源10，該熱 源10具有一使該熱源10不至於過熱損壞之保護溫度T1， 該熱介面材料預製體包括一柔性基體31、填充於該柔性 基體31中之複數第二金屬顆粒3211及複數奈米碳管322 ，該第二金屬顆粒3211之粒徑小於100奈米，且該第二金 屬顆粒3211於該粒徑下之熔融溫度T2小於該保護溫度T1 。優選地，該保護溫度T1為120°C，該第二金屬顆粒 3211之粒徑小於50奈米。本實施例中，該第二金屬顆粒 3211為粒徑於20奈米左右之銀顆粒，其於該粒徑之熔融 溫度T2為100°C左右。該第二金屬顆粒3211也可為粒徑 範圍於10奈米~20奈米之錫鉛合金顆粒，其於該粒徑之熔 098118138 表單編號A0101 第8頁/共19頁 0982030786-0 201043687 融溫度T2為91°C。 _ jmS102，將該熱介面材料預製體設置於熱源iq表面。 可通過將該熱介面材料預製體直接設置於熱源1〇表面； 或將該熱介面材料預製體溶解於—溶龍覆於該熱源ι〇 表面’再揮發掉該溶劑而使該齡面材料預製體設置於 熱源10表面。 _ #驟S103，加熱該熱介面材料預製體，使該第二金屬顆 Ο ❹ 粒3211熔融團聚。具體地，該加熱溫度於該第二金屬顆 粒3211於該粒徑之熔融溫度T2與保護溫度T1之間。該第 二金屬顆粒3211於、熔融態下會相互結合形成具較大粒徑 之第-金屬顆粒32卜該第-金屬顆粒321之粒控大於 1〇〇奈米。其中，部分第一金屬顆粒321可複合至少一奈 米碳管322形成複合導熱顆粒32，此時，該複合導熱顆粒 32之粒徑也大於1〇〇奈米。可以理解，該第一金屬顆粒 321與第二金屬顆粒3211之材料相同，粒徑不同，該第一 金屬顆粒321之粒徑大於100奈米，而第二金屬顆粒32ιι 之粒徑則小於1〇〇秦米；該第一金屬顆粒321與第二金屬 顆粒3211具有不同之物理性f，這仙為當金屬材料粒 徑小於100奈米時’尤其係粒徑小於5〇奈求時，其炫點隨 著粒控之減小而減小，而該金屬材料於粒徑大於1〇〇奈米 時’其熔點則保持穩定且大於該金屬材料於粒徑小於ι〇〇 奈米時之熔點。該第二金屬顆粒3211於一定條件下可轉 換為第-金屬顆粒32卜如複數第二金屬顆粒3211於溶融 態相互融合而轉換成第一金屬顆粒321。在本實施例中， 該加熱溫度小於12(TC，具體地，當該第二金屬顆粒32ιι 098118138 表單編號A0101 第9頁/共19頁 0982030786-0 201043687 為粒徑20奈米之銀顆粒時，該加熱溫度為100°C〜120°C :當該第二金屬顆粒3211為粒徑範圍於10奈米~20奈米 之錫鉛合金顆粒時，該加熱溫度為91°C〜120°C。 [0024] 步驟S104，將一散熱裝置20扣合於該熱介面材料預製體 表面，使該熱介面材料預製體位於該熱源10與散熱裝置 20之間。在該熱介面材料預製體於熔融態時將該散熱裝 置20扣合於該熱介面材料預製體表面，可靈活調節該散 熱裝置20與該熱源10之間之距離。可以理解，該熱介面 材料預製體於熔融態下，更容易被壓縮，從而能夠進一 步縮短該散熱裝置20與該熱源10之間之距離，縮短熱傳 遞路控。 [0025] 步驟S105，冷卻該熱介面材料預製體，形成熱介面材料 30於熱源10表面。冷卻該熱介面材料預製體形成熱介面 材料30後，該第一金屬顆粒321之粒徑大於100奈米，且 其於該粒徑下之熔融溫度大於該保護溫度T1。具體地， 當該第一金屬顆粒321為粒徑大於100奈米之銀顆粒時， 其熔融溫度為962°C ;當該第一金屬顆粒321為粒徑大於 100奈米之錫鉛合金顆粒時，其熔融溫度為183°C。可以 理解，該熱介面材料預製體經過冷卻形成熱介面材料30 後，當再次將溫度升高到該第一金屬顆粒321於較小粒徑 之熔融溫度T2時，該複合有奈米碳管之第一金屬顆粒321 或複合導熱顆粒32也不會熔融，從而能夠保持於固態下 工作。 [0026] 在該步驟S1 02中，還可包括如下步驟：將一散熱裝置20 扣合於該熱介面材料預製體表面，使該熱介面材料預製 098118138 表單編號A0101 第10頁/共19頁 201043687 體位於該熱源10與散熱裝置20之間。且，此時該步驟 S104將不再必要。 ^ 闺㈣備枝彻錢㈣妹徑則、於刚奈料其炼融 溫度變化之特性，將導熱絲高之金屬與奈米碳管於較 低之溫度下複合’從而獲得導熱性能較好之熱介面材料 。且該熱介面材料於形成過程中，該金屬材料具有一相 變之過程’料態之金屬材料能财效浸_該熱介面 材料與熱源接觸表面間之間隙，從而使該熱介面材料與 〇 a熱源及散熱裝置為面接觸，減"丨、該熱介面材料與熱源 及散熱裝置之間之熱阻，且該熔融溫度不至於對熱源造 成損壞；其次，該複合導熱顆粒具有軾大之粒徑，減小 該複合導熱顆粒與柔性基體之間之介面熱阻；再次該 複合導熱顆粒於熱源工作時始終保持固態，保持了金屬 材料及奈米碳管優異之導熱性能^ [0θ28]該熱介面材料中之奈米碳管複合於第一金屬顆粒中形成 複合導熱顆粒。由於該複合導熱顆粒之熱傳遞方向無方 〇 向性限制，由該複數複合導熱顆粒相互搭接而形成之導 熱通道，具有較短之熱傳遞路徑；且，由於複合導熱顆 粒具有較大之粒徑，相互搭接而形成之複合導熱顆粒之 間之熱阻較小。因此，該熱介面材料有效利用了奈米碳 管優異之導熱性能，具有較好之導熱性能。 [0029] 綜上所述，本發明確已符合發明專利之要件，遂依法提 出專利申請。惟，以上所述者僅為本發明之較佳實施例 ，自不能以此限制本案之申請專利範圍。舉凡習知本案 技藝之人士援依本發明之精神所作之等效修飾或變化， 098118138 表單煸號A0101 第11頁/共19頁 0982030786-0 201043687 皆應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 [0030] [0031] [0032] [0033] [0034] 圖1係本發明實施例提供之電子裝置之結構示意圖。 圖2係圖1中熱介面材料微觀結構示意圖。 圖3係本發明製備熱介面材料之熱介面材料預製體之微觀 結構示意圖。 圖4係本發明實施例提供之電子裝置之製備方法之流程示 意圖。 【主要元件符號說明】 電子裝置 1 π π 1 U U 熱源 10 散熱裝置 20 熱介面材料 30 柔性基體 31 複合導熱顆粒 32 第一金屬顆粒 321 第二金屬顆粒 3211 奈米碳管 322 098118138 表單編號A0101 第12頁/共19頁 0982030786-0[0018] The composite thermally conductive particles 32 are formed by combining the first metal particles 321 with at least one carbon nanotube 322. Specifically, the brick carbon nanotubes 322 are dispersed in the first metal particles 321 . The composite thermally conductive particles 32 effectively utilize the excellent thermal conductivity of the carbon nanotubes 322 and greatly reduce the interface thermal resistance between the plurality of carbon nanotubes 322 dispersed in the same first metal particles 321 . Since the heat transfer direction of the composite heat conductive particles 32 is not directional, the heat conduction channel formed by the overlapping of the plurality of composite heat conductive particles 32 has a short heat transfer path; and, since the composite heat conductive particles 32 have a larger The particle size and the thermal resistance between the composite thermally conductive particles 32 overlapping each other are small. Therefore, the thermal interface material 100 effectively utilizes the excellent thermal conductivity of the carbon nanotube 322 098118138 Form No. A0101 0982030786-0 201043687, and has good thermal conductivity. [0019] In the thermal interface material 30, a plurality of first metal particles 321 which are not composited with the carbon nanotubes 322 may be further included, and the first metal particles 321 have a particle diameter of more than 100 nm. That is, the thermally conductive particles in the flexible substrate 31 include the composite thermally conductive particles 32 and the first metal particles 321 . At this time, the heat conduction path is formed by the plurality of composite thermally conductive particles 32 and the plurality of first metal particles 321 being overlapped with each other. It can be understood that when the thermal interface material 30 further includes a plurality of first metal particles 321 that are not composited with the carbon nanotubes 322, the thermal interface material 30 can also be described as follows, the thermal interface material 30 includes a flexible substrate 31 and A plurality of first metal particles 321 dispersed in the flexible substrate 31. A portion of the first metal particles 321 are combined with the carbon nanotubes 322 to form a plurality of composite thermally conductive particles 32. Referring to FIG. 3 and FIG. 4, the method for fabricating the electronic device 100 includes the following steps. [0021] Step S101, providing a thermal interface material preform and a heat source 10 having a protection temperature T1 for preventing the heat source 10 from being damaged by overheating, the thermal interface material preform comprising a flexible substrate 31, filled in a plurality of second metal particles 3211 and a plurality of carbon nanotubes 322 in the flexible substrate 31. The second metal particles 3211 have a particle diameter of less than 100 nm, and the second metal particles 3211 have a melting temperature T2 at the particle diameter. Less than the protection temperature T1. Preferably, the protective temperature T1 is 120 ° C, and the second metal particles 3211 have a particle diameter of less than 50 nm. In the present embodiment, the second metal particles 3211 are silver particles having a particle diameter of about 20 nm, and the melting temperature T2 of the particle diameter is about 100 °C. The second metal particles 3211 may also be tin-lead alloy particles having a particle size ranging from 10 nm to 20 nm, and the melting of the particle size is 098118138. Form No. A0101 Page 8 / 19 pages 0982030786-0 201043687 Melting temperature T2 is 91 °C. _ jmS102, the thermal interface material preform is disposed on the surface of the heat source iq. The ageing material may be prefabricated by directly disposing the hot interface material preform on the surface of the heat source 1; or dissolving the hot interface material preform on the surface of the heat source ι〇 and then volatilizing the solvent The body is disposed on the surface of the heat source 10. _#Step S103, heating the thermal interface material preform to melt agglomerate the second metal ruthenium granule 3211. Specifically, the heating temperature is between the melting temperature T2 of the second metal particle 3211 and the protective temperature T1. The second metal particles 3211 are combined with each other in a molten state to form a first metal particle 32 having a larger particle diameter. The grain size of the first metal particle 321 is greater than 1 nanometer. The partial first metal particles 321 may be combined with at least one carbon nanotube 322 to form composite thermally conductive particles 32. At this time, the composite thermally conductive particles 32 have a particle diameter greater than 1 nanometer. It can be understood that the first metal particles 321 are the same as the second metal particles 3211, and the particle diameters are different. The first metal particles 321 have a particle diameter larger than 100 nm, and the second metal particles 32 ι have a particle diameter smaller than 1 〇. 〇秦米; the first metal particles 321 and the second metal particles 3211 have different physical properties f, which is when the metal material particle size is less than 100 nm, especially when the particle size is less than 5 〇 The point decreases as the particle size decreases, and the metal material has a melting point that remains stable at a particle size greater than 1 nanometer nanometer and is greater than the melting point of the metal material when the particle size is less than 1 nanometer. The second metal particles 3211 can be converted into the first metal particles 32 under a certain condition, for example, the plurality of second metal particles 3211 are fused to each other in the molten state to be converted into the first metal particles 321 . In the present embodiment, the heating temperature is less than 12 (TC, specifically, when the second metal particle 32 ι 098118138 form number A0101 page 9 / 19 pages 0982030786-0 201043687 is a silver particle having a particle size of 20 nm, The heating temperature is from 100 ° C to 120 ° C. When the second metal particles 3211 are tin-lead alloy particles having a particle diameter ranging from 10 nm to 20 nm, the heating temperature is from 91 ° C to 120 ° C. [0024] Step S104, a heat dissipating device 20 is fastened to the surface of the thermal interface material preform, and the thermal interface material preform is located between the heat source 10 and the heat sink 20. The hot interface material preform is in a molten state. The heat dissipating device 20 is fastened to the surface of the thermal interface material preform, and the distance between the heat dissipating device 20 and the heat source 10 can be flexibly adjusted. It can be understood that the thermal interface material prefabricated body is more easily in the molten state. Compression, thereby further shortening the distance between the heat sink 20 and the heat source 10, and shortening the heat transfer path. [0025] Step S105, cooling the hot interface material preform to form a thermal interface material 30 on the surface of the heat source 10. Cooling The thermal interface After the preform is formed into the thermal interface material 30, the first metal particles 321 have a particle diameter greater than 100 nm, and the melting temperature at the particle diameter is greater than the protection temperature T1. Specifically, when the first metal particles 321 When the silver particles having a particle diameter of more than 100 nm have a melting temperature of 962 ° C; when the first metal particles 321 are tin-lead alloy particles having a particle diameter of more than 100 nm, the melting temperature is 183 ° C. It is understood that after the thermal interface material preform is cooled to form the thermal interface material 30, when the temperature is raised again to the melting temperature T2 of the first metal particle 321 at a smaller particle size, the composite has a carbon nanotube A metal particle 321 or a composite heat conductive particle 32 is also not melted, so that it can be kept in a solid state. [0026] In this step S102, a step of: fastening a heat sink 20 to the heat interface material may be further included. Prefabricated surface, the thermal interface material is prefabricated 098118138 Form No. A0101 Page 10 / 19 pages 201043687 The body is located between the heat source 10 and the heat sink 20. Moreover, this step S104 will no longer be necessary. ^ 闺 (4) Branches of money (4) The diameter is the characteristics of the change of the melting temperature of the material, and the metal of the heat conducting wire is composited with the carbon nanotube at a lower temperature to obtain a thermal interface material having better thermal conductivity. The thermal interface material is obtained. During the formation process, the metal material has a phase change process. The metal material of the material state can be immersed in the gap between the contact surface of the heat interface material and the heat source, so that the heat interface material and the heat source and heat sink of the heat source device For surface contact, reduce the thermal resistance between the thermal interface material and the heat source and the heat sink, and the melting temperature does not cause damage to the heat source; secondly, the composite thermally conductive particle has a large particle size and is reduced. The interface thermal resistance between the composite thermally conductive particles and the flexible substrate; again the composite thermally conductive particles remain solid when operating in the heat source, maintaining the excellent thermal conductivity of the metal material and the carbon nanotubes ^ [0θ28] in the thermal interface material The carbon nanotubes are composited in the first metal particles to form composite thermally conductive particles. Since the heat transfer direction of the composite heat conductive particles is not limited by the square direction, the heat conduction channel formed by the overlapping of the plurality of composite heat conductive particles has a short heat transfer path; and, because the composite heat conductive particles have larger particles The thermal resistance between the composite thermally conductive particles formed by the mutual overlapping is small. Therefore, the thermal interface material effectively utilizes the excellent thermal conductivity of the carbon nanotubes and has good thermal conductivity. [0029] In summary, the present invention has indeed met the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Any person skilled in the art will be able to make equivalent modifications or variations in accordance with the spirit of the present invention. 098118138 Form No. A0101 Page 11 of 19 0982030786-0 201043687 All should be covered by the following patents. BRIEF DESCRIPTION OF THE DRAWINGS [0034] FIG. 1 is a schematic structural diagram of an electronic device according to an embodiment of the present invention. 2 is a schematic view showing the microstructure of the thermal interface material in FIG. Fig. 3 is a schematic view showing the microstructure of a thermal interface material preform for preparing a thermal interface material according to the present invention. FIG. 4 is a schematic flow chart showing a method of fabricating an electronic device according to an embodiment of the present invention. [Main component symbol description] Electronic device 1 π π 1 UU Heat source 10 Heat sink 20 Thermal interface material 30 Flexible substrate 31 Composite thermally conductive particles 32 First metal particles 321 Second metal particles 3211 Carbon nanotubes 322 098118138 Form No. A0101 No. 12 Page / Total 19 pages 0982030786-0