201009914 九、發明說明： 【發明所屬之技術領域】 本發明係有關於-種LED金屬散熱晶圓的切割方法， 尤其是利職影侧麟、铸侧技似及雷射切割製 程0 【先前技術】 〇 在LK)技術的快速演進下，高亮度LED照明燈具的光 輸出效率已不輸傳統燈具，如水銀燈或高壓鈉燈，再加上 具有輕薄、省電和環保等優點，因而成為市場上的明星技 術。不過，高亮度LED的發纽麵溫度較職，比如當 發光層之溫度由室溫增至l〇〇°C時’綠光的發光效率約為 9(U ’白光約為85% ’而紅光的發光效率則只剩下不到， 因此散熱成為首要解決之技術問題。 〇 一般，LED主要是由具發光特性的磊晶層（EPI)以及具 優異散熱能力的散熱晶圓（WAFER)在高溫高壓下貼合組成 LED晶圓，如第一圖與第二圖所示，其中第一圖為習用技術 之LE：D晶圓示意圖，而第二圖為習用技術之LED晶圓斷面 示意圖。如第一圖所示，LE：D晶圓1具有複數個磊晶體3， 而第二圖顯示該等磊晶體3是位於金屬散熱晶圓5的第一 面F1 ’相鄰蠢晶體3被蠢晶體間隔區31分隔開，而金屬散 熱晶圓5的厚度為T。 5 201009914 為達到1¾效率的散熱要求’金屬散熱晶圓5通常採用 钥金屬’尤其是高亮度LED的散熱片，因為翻的鱗脹係 數接近蠢晶層的麟脹錄’同時它的熱傳效果非常優 良、可以較其他非金屬散熱片提供更高的散熱效果。此外， 鉬是金屬材質，在LED生產線上的製造過程中不會有破裂 的困擾產生。通常一片50麵直徑的led晶圓可以切割出2 萬顆LED，因此切割製程是必要的處理，而切割處理的良率 變得很重要。。 然而，習用技術的缺點是，鉬金屬散熱晶圓不容易切 割，因為若採用鑽石切割法，則一般的鑽石圓鑛片會因高 磨損以及鉬屑卡入鑽石缝隙，而造成鑽石鋸片無法使用。 若採用目别較南階的雷射切割法，則在雷射高溫融溶切割 時’钥金屬被切斷部位很容易發生回融現象，而為達到切 斷的目的，就必須增加雷射能量並減低切割速度，以強制 鉬熔解且氣化揮發，如此卻會造成磊晶體受熱太多以及太 久，導致光電係數不穩定，而使得發光效率不均且降低。 因此，需要一種不增加雷射功率且不加長雷射切割時 間的切割方法’以避免磊晶體受高熱影響而降低發光效率。 【發明内容】 本發明之主要目的在於提供一種切割LED金屬散熱晶 圓方法’利用微影蝕刻技術以及電解蝕刻技術以降低具有 6 201009914 複數個LED晶粒的金屬散熱晶圓的厚度，並藉雷射切割技 術切割該金屬散熱晶圓’進而切割開該等LED晶粒，而由 於金屬散熱晶圓中需切割處理的厚度已大幅減小，因此在 進行雷射切割時，可縮短處理時間，降低金屬散熱晶圓所 吸收的熱量，藉以避免LED晶粒在切割過程中受到高熱影 響而降低LED的光電性能。 該微影蝕刻技術是在散熱晶圓不具有磊晶體的表面 上，塗佈光阻層並對該光阻層定義出光阻層圖案，該光阻 層圖案須對齊散熱晶圓另—面上縣晶體，並浸泡於具適 當電解侧液的電解爛射，加正電壓至散熱晶圓，加 負電壓至參考電極，比如石墨電極，#以進行電解侧處 理。未被光Μ ®案覆蓋住的金屬會被轉成金屬離子， 因此散熱晶圓的厚度會減少。當散熱晶_厚度降到否一 預設厚度時，便停止進—步電解侧處理。接著，利用去 光阻劑去轉光阻層，錢進行雷射切割處理。 由於，散熱晶圓的厚度已大幅減少，所以雷射切割處 理的雷射神不需增加，且__也不需加長，因而解 決習用技術關題，維_礙晶_發光特性，進而提 高切割處理的良率。 【實施方式】 以下配合圖示衫件符騎本發狀實财式做更詳 7 201009914 、’’田的說月俾使熟習該項技藝者在研讀本說明書後能據以 實施。 參考第三圖’本發明之LED金屬散熱晶圓切割方法之 流程圖’並配合第四圖，本發明之LED金屬散熱晶圓切割 方法之光阻層示意圖。如第三圖的步驟S1G所示，在不具 蠢晶體3的金屬散熱晶圓5之第二面F2上，塗佈光阻層| 並定義出光阻層圖案，且該光阻層圖案對齊第—面打上的 蠢晶體3 ’如第四圖所示，其中光阻層間隔區71是表示該 光阻層中被去除掉的部分。 接著’進入第三圖的步驟S12，進行電解钱刻處理以麵 刻光阻層間隨71嶋金屬散熱晶® 5的金屬，結果如第 五圖所不，該金屬散熱晶圓5的電解餘刻區51被電解餘刻 至預設厚度T1。 x 接著，進入第三圖的步驟Sl4，去除光阻層7 ,結果如 第六圖所示。最後進入第三圖的步驟S16，對電解餘刻區 51的金屬進行雷射切割處理’以完全去除掉電解餘刻區 51，結果如第七圖所示。 °° 在本發明的較佳實施例中，該金屬散熱晶圓5的金屬 包括鉬金屬或是導電金屬散熱晶圓。 在步驟S12巾，電解綱處理是使用具有電解餘刻液 以及冷卻系_電解_槽，圖中未顯示。電解糊液包 8 201009914 括水、金屬離子以及幫助導電的導電物質，該導電物質包 括硫酸、硝酸、磷酸以及鹽酸的至少其中之一。冷卻系統 包括幫浦、管線系統以及散熱片組件，用以降低電解蚀刻 液的溫度’避免蠢晶體因兩溫而影響光電特性，其中幫浦 將該電解餘刻液抽離該電解钱刻槽，經該管線系統流過該 散熱片組件’用以冷卻該電解蝕刻液，並藉該管線系統回 到該電解餘刻槽。 此外，電解钱刻槽進一步包括平面電極，材質可為銅、 石墨或其它適當的導電金屬。金屬散熱晶圓5連接到外部 電源的正極端，將平面電極連接到外部電源的負極端，且 該平面電極位於該光阻層圖案的同一側。當外部電源通電 時，正極端的金屬因接收正電壓而形成帶正電的金屬離 子，而負極端的平面電極將水分子電解出氫氣，藉以形成 電解迴路。由於金屬持續轉變成金屬離子，因此[金屬散熱 晶圓5的厚度變薄，可依據法拉第定理得到電解時間與鉬 散熱晶圓5的厚度的關係，並藉以控制金屬散熱晶圓5 厚度。 … 、 在第五圖中，金屬散熱晶圓5的預設厚度T1具一最小 值，以避免金屬散熱晶圓5的機械強度不夠而破裂，較佳 實施例是，該厚度可降健原赠的15%，且賴的雷 割功率不需增加，因此Ή最小可達〇.ΐ5*τ。 由於金屬散熱晶圓5的厚度由τ大幅縮小至T1，因此 在步驟S16巾，雷射蝴所需的神便*需提高，且處理 時間也不需延長’_避免雷射所產生的熱量影響羞晶體3 9 201009914 的光電性能，包括發光效率以及均一性。 因此，本發明利用電解姓刻處理，降低金屬散熱晶圓 的厚度’在以低功率的雷射切割以切割開磊晶體，形成具 金屬散熱片與磊晶體結構的LE：D顆粒。 【圖式簡單說明】 第一圖為顯示習用技術之LED金屬散熱晶圓之示意圖。 第二圖為顯示習用技術之led金屬散熱晶圓之斷面示意 圖。 第三圖為顯示本發明之LED金屬散熱晶圓切割方法之流程 圖。 第四圖為顯示本發明之le:d金屬散熱晶圓切割方法之光阻 層示意圖。 第五圖為顯示本發明之LED金屬散熱晶圓切割方法之電解 餘刻區示意圖。 第六圖為顯示本發明之LED金屬散熱晶圓切割方法之去除 光阻層後之示意圖。 第七圖為顯示本發明之LED金屬散熱晶圓切割方法之雷射 切割後之示意圖。 【主要元件符號說明】 1 LED晶圓 3蠢晶體 201009914 5金屬散熱晶圓 7光阻層 31蟲晶體間隔區 51電解钱刻區 71光阻層間隔區 F1第一面 F2第二面 © S10、S12、S14、S16 步驟 T、T1厚度201009914 IX. Description of the invention: [Technical field of the invention] The present invention relates to a method for cutting a metal foil heat-dissipating wafer, in particular, a front-end side, a cast side, and a laser cutting process. 〇 Under the rapid evolution of LK technology, the light output efficiency of high-brightness LED lighting fixtures has not lost traditional lamps, such as mercury lamps or high-pressure sodium lamps, coupled with the advantages of lightness, power saving and environmental protection, thus becoming the market. Star technology. However, the brightness of the high-brightness LED is relatively high. For example, when the temperature of the luminescent layer is increased from room temperature to l〇〇°C, the luminous efficiency of green light is about 9 (U 'white light is about 85%' and red The luminous efficiency of light is only less than that, so heat dissipation is the primary technical problem. In general, LEDs are mainly made up of an epitaxial layer (EPI) with luminescent properties and a heat sinking wafer (WAFER) with excellent heat dissipation capability. The LED wafer is laminated under high temperature and high pressure, as shown in the first figure and the second figure, wherein the first figure is a schematic diagram of the LE:D wafer of the conventional technology, and the second figure is a schematic diagram of the LED wafer section of the conventional technology. As shown in the first figure, the LE:D wafer 1 has a plurality of epi-crystals 3, and the second figure shows that the epi-crystals 3 are located on the first surface F1 of the metal heat-dissipating wafer 5 The stray crystal spacers 31 are separated, and the metal heat sink wafer 5 has a thickness of T. 5 201009914 To achieve a heat dissipation requirement of 13⁄4 efficiency, the metal heat sink wafer 5 usually uses a key metal 'especially a high-brightness LED heat sink because The swell expansion coefficient is close to the swell of the stupid layer, and its heat transfer It is very good and can provide higher heat dissipation than other non-metal heat sinks. In addition, molybdenum is made of metal and will not be cracked during the manufacturing process on the LED production line. Usually a 50-sided diameter led wafer The cutting process can cut 20,000 LEDs, so the cutting process is necessary, and the yield of the cutting process becomes important. However, the disadvantage of the conventional technology is that the molybdenum metal heat sink wafer is not easy to cut because diamond cutting is used. In the case of a normal diamond ore piece, the diamond saw blade cannot be used due to high wear and molybdenum chips stuck in the diamond gap. If the laser cutting method is used in the south order, the laser is cut at high temperature in the laser. When the key metal is cut, the remelting phenomenon is easy to occur. To achieve the purpose of cutting, it is necessary to increase the laser energy and reduce the cutting speed to force the molybdenum to melt and vaporize and volatilize, which will cause the crystal to be heated. Too much and too long, the photoelectric coefficient is unstable, and the luminous efficiency is uneven and reduced. Therefore, there is a need for a laser that does not increase the laser power and does not lengthen the laser. The cutting method of time is to prevent the epitaxial crystal from being affected by high heat and reduce the luminous efficiency. SUMMARY OF THE INVENTION The main object of the present invention is to provide a method for cutting an LED metal heat-dissipating wafer using a photolithography etching technique and an electrolytic etching technique to reduce the 201009914 The thickness of the metal heat sink wafer of a plurality of LED dies, and the metal heat sink wafer is cut by laser cutting technology to cut the LED dies, and the thickness of the metal heat sink wafer to be cut is greatly increased Reduced, so when performing laser cutting, the processing time can be shortened, and the heat absorbed by the metal heat-dissipating wafer can be reduced to avoid the high-heat effect of the LED die during the cutting process, thereby reducing the photoelectric performance of the LED. Applying a photoresist layer on the surface of the heat-dissipating wafer that does not have an epi-crystal, and defining a photoresist layer pattern on the photoresist layer, the photoresist layer pattern must be aligned with the heat-dissipating wafer on the other surface of the crystal, and immersed in Electrolytic blasting with appropriate electrolysis side liquid, add positive voltage to the heat sink wafer, add negative voltage to the reference electrode, such as graphite electrode, #以Side in electrolysis process. Metals that are not covered by the Lightning ® case are converted to metal ions, so the thickness of the heat sink wafer is reduced. When the thickness of the heat-dissipating crystal _ is reduced to a predetermined thickness, the electrolysis side treatment is stopped. Then, using a photoresist to remove the photoresist layer, the laser is subjected to laser cutting. Since the thickness of the heat-dissipating wafer has been greatly reduced, the laser of the laser cutting process does not need to be increased, and __ does not need to be lengthened, so that the problem of the conventional technology is solved, and the ray-emitting property is improved, thereby improving the cutting. The yield of processing. [Embodiment] The following is a more detailed description of the shirts and the style of the hairdressing. 7 201009914, ‘’’’’’’’’’’’’’’’’ Referring to the third drawing 'flowchart of the LED metal heat-dissipating wafer cutting method of the present invention' and the fourth figure, the photoresist layer of the LED metal heat-dissipating wafer cutting method of the present invention is schematic. As shown in step S1G of the third figure, on the second surface F2 of the metal heat sink wafer 5 having no stray crystal 3, the photoresist layer is coated and a photoresist layer pattern is defined, and the photoresist layer pattern is aligned. The surface of the stupid crystal 3' is shown in the fourth figure, wherein the photoresist layer spacer 71 is a portion of the photoresist layer which is removed. Then, in step S12 of the third figure, electrolytic etching is performed to face the metal of the 71 嶋 metal heat-dissipating crystal layer 5 between the photoresist layers. As a result, as shown in the fifth figure, the electrolysis of the metal heat-dissipating wafer 5 is left. The region 51 is electrolyzed to a predetermined thickness T1. x Next, proceeding to step S14 of the third figure, the photoresist layer 7 is removed, and the result is as shown in the sixth figure. Finally, in step S16 of the third drawing, the metal of the electrolytic remnant zone 51 is subjected to a laser cutting process to completely remove the electrolysis residual region 51, and the result is as shown in the seventh figure. °° In a preferred embodiment of the invention, the metal of the metal heat sink wafer 5 comprises a molybdenum metal or a conductive metal heat sink wafer. In the step S12, the electrolysis process is performed using an electrolysis residual solution and a cooling system_electrolytic_tank, which is not shown in the drawing. Electrolytic paste package 8 201009914 includes water, metal ions, and a conductive substance that helps to conduct electricity, and the conductive substance includes at least one of sulfuric acid, nitric acid, phosphoric acid, and hydrochloric acid. The cooling system includes a pump, a pipeline system, and a heat sink assembly to reduce the temperature of the electrolytic etching solution. 'After the stupid crystal affects the photoelectric characteristics due to the two temperatures, the pump pulls the electrolytic residual liquid away from the electrolytic money groove. The heat sink assembly is passed through the line system to cool the electrolytic etching solution, and the line system is returned to the electrolytic residual groove. In addition, the electrolysis groove further includes a planar electrode made of copper, graphite or other suitable conductive metal. The metal heat sink wafer 5 is connected to the positive terminal of the external power source, and the planar electrode is connected to the negative terminal of the external power source, and the planar electrode is located on the same side of the photoresist layer pattern. When the external power source is energized, the metal at the positive terminal forms a positively charged metal ion by receiving a positive voltage, and the planar electrode at the negative terminal electrolyzes hydrogen molecules to form an electrolytic circuit. Since the metal is continuously converted into metal ions, [the thickness of the metal heat-dissipating wafer 5 is thinned, and the relationship between the electrolysis time and the thickness of the molybdenum-dissipating wafer 5 can be obtained according to Faraday's theorem, and the thickness of the metal heat-dissipating wafer 5 can be controlled. In the fifth figure, the predetermined thickness T1 of the metal heat dissipating wafer 5 has a minimum value to avoid the mechanical strength of the metal heat dissipating wafer 5 being broken and broken. In the preferred embodiment, the thickness can be reduced. 15%, and the lightning power of the Lai does not need to be increased, so the minimum is 〇.ΐ5*τ. Since the thickness of the metal heat-dissipating wafer 5 is greatly reduced from τ to T1, in step S16, the magic required for the laser butterfly needs to be increased, and the processing time does not need to be extended. _ Avoid the heat generated by the laser Photoelectric properties of Shame Crystal 3 9 201009914, including luminous efficiency and uniformity. Therefore, the present invention utilizes electrolysis processing to reduce the thickness of the metal heat-dissipating wafer. The laser is cut at a low power to cut the open crystal to form LE:D particles having a metal heat sink and an epitaxial crystal structure. [Simple description of the diagram] The first figure is a schematic diagram showing the LED metal heat sink wafer of the conventional technology. The second figure is a schematic cross-sectional view of a led metal heat sink wafer showing conventional technology. The third figure is a flow chart showing the cutting method of the LED metal heat-dissipating wafer of the present invention. The fourth figure is a schematic diagram showing the photoresist layer of the LE:d metal heat sink wafer cutting method of the present invention. The fifth figure is a schematic view showing an electrolytic residual region of the LED metal heat-dissipating wafer cutting method of the present invention. The sixth figure is a schematic view showing the removal of the photoresist layer of the LED metal heat-dissipating wafer cutting method of the present invention. The seventh figure is a schematic view showing the laser cutting method of the LED metal heat-dissipating wafer of the present invention after laser cutting. [Main component symbol description] 1 LED wafer 3 stupid crystal 201009914 5 metal heat sink wafer 7 photoresist layer 31 insect crystal spacer 51 electrolytic money engraving area 71 photoresist layer spacer F1 first side F2 second side © S10, S12, S14, S16 Step T, T1 thickness