480537 五、發明說明（l) 發明領域： 本發明與一種場發射顯示器有關，特別是一種利用表 面處理的方式大幅改善奈米碳管場發射顯示器電流密度之 方法。 發明背景： 奈米碳管場發射（f i e 1 d e m i s s i ο η )顯示器係將一由直 徑約數十奈米大小的細長碳管、有機黏結劑及銀粉等混成 之漿料網印並圖樣化於陰極基板的陰極上，以構成像素陣 列的電子發射源。而陰極基板上的銀陰極也已在其網印形 成過程先圖樣化了。然後再利用電場將冷電子由裸露在奈 米碳官發射層上之奈米碳管（carbon nanotube)的尖端發 射，再利用電場加速電子，使電子在真空的環境下撞擊相 對應之陽極（例如氧化銦錫（IT0)的基板）像素陣列上的營 光粉，而產生發光。相較於傳統的陰極射線管通常應用埶 離子化電子（therm1〇nically emiUed electr〇ns)自鎢，絲 發射的方式有甚大的差異。 奈米碳管場發射顯示器芻你姑供 ^主办土 m 一 ；叔作技術，清參考圖一所示的 橫截面示意圖，首先以網印的 1的方式用刮刀把銀等導電漿料 刮過已圖樣化之網板以形成條壯^代〇 η认甘上，λ y从餘狀陰極2 0於基板1 〇上此步驟 即為習知技術所稱的網印。杻裟收古"从* 乂 供者將直徑約奈米〜數十奈米 480537 五、發明說明（2) 〜〜 及長約次微米〜數微米的碳管利用有機樹脂做為钻结 劏與銀粉一起混合以調製成CNT漿料，再用刮刀把漿料 (p^ste)刮過已圖樣化之網板的網目而將其塗佈於基板的 ΐΛΙΐ:形成CNT像素陣列層30。網印後尚需以約 、行#人烤（s 〇 f t b a k i n g )以去除具揮發性成分 有機溶劑。再以約3 5 0 — 5 μγ古、、w植姓，平如I风刀之 古德抖日匕*门 问，燒結（sintering)以去除 有機私U曰並固著CN1^陰極基板上。 i Ϊ t私製作費用便宜，但這不是唯-優點，利用場 电射做為顯示器，更具有整個電子搶的厚度僅約為〇. 2襲 而已的好處’此外’平面面積亦有很大的可使用範圍，從 :至數平方公分大小’到大至數百平方公分㈣，因此非 书適：：超溥型平面顯示器。不㉟，做為顯示器的場發射 源不是而要穩定、長時間使用的可靠度，而且更重要的 是場發射^電流密度至少需達到〇.卜lmA/_2,才足以產 生足：的売度與均勻度，而達到上述之電流所需的電 場強度當然是愈低愈好’最好低於25 V/// 。 in 0 對於上述之習知技術，由於CNT場發射 器的電性 量測特性（即電流密度對電場強度作圖 〜裸露 之奈米碳管並且固著於陰極的數量= 般 =;如：上述的CNT場發射陰極不 特別理，電流密 度甚小，除非加極高之電壓，請參考圖二:處理 圖。 圖中曲線11Q，是以上述f知技術所製作，對電性量測所480537 V. Description of the invention (l) Field of the invention: The present invention relates to a field emission display, in particular to a method for greatly improving the current density of a nano-carbon tube field emission display by using surface treatment. Background of the Invention: Nano carbon tube field emission (fie 1 demissi ο η) displays are screen-printed and patterned on a cathode from a slurry of a slender carbon tube with a diameter of about several tens of nanometers, an organic binder, and silver powder. The cathode of the substrate is used to constitute an electron emission source of the pixel array. The silver cathode on the cathode substrate has been patterned during the screen printing process. Then use the electric field to emit cold electrons from the tips of carbon nanotubes exposed on the nano-carbon official emission layer, and then use the electric field to accelerate the electrons, so that the electrons impact the corresponding anode in a vacuum environment (for example, A light emitting powder is generated on the indium tin oxide (IT0) substrate) pixel array. Compared with the traditional cathode-ray tube, which generally uses 埶 ionized electrons (thermonely emiUed electrns) from tungsten, the way of wire emission is very different. Nanometer carbon tube field emission display. You will be the host of the sponsor. I will refer to the cross-section diagram shown in Figure 1 for the technology. First, use a squeegee to scrape silver and other conductive paste through the screen printing method. The screen has been patterned to form strips. On the surface, λ y is from the residual cathode 20 on the substrate 10. This step is known as screen printing in the conventional technology.杻 裟 Collecting from ancient times " From * 乂 Donors will use a diameter of about nanometers ~ several tens of nanometers 480537 Ⅴ. Description of the invention (2) ~ ~ and carbon tubes with a length of about two microns to several microns use organic resin as a drill knot 劏It is mixed with silver powder to prepare a CNT paste, and then the paste (p ^ ste) is scraped through the mesh of the patterned stencil with a doctor blade and applied to the substrate ΛΛ1: forming a CNT pixel array layer 30. After screen printing, it is still necessary to bake (sf f b a k i n g) in order to remove volatile organic solvents. Then use about 3 5 0 — 5 μ y, y, y, y, y, y, y, y, y, y, y, y, y, y, y, y, y, y, y, y, y, k, y, y, y, y, y, y, y, y, y, y, y, y, y, y, y, y, (y, y, k, y, k, y, y, y, y, y, y, y, d, d, d, d, d, y, d, y, y, d, sintering to remove the organic substrate and fix it on the cathode substrate. i Ϊ t private production costs are cheap, but this is not the only advantage, the use of field radio as a display, but also has the thickness of the entire electronic grab is only about 0.2, the advantage of only 'in addition' the planar area is also very large The usable range is from: to a few square centimeters' to hundreds of square centimeters. Therefore, it is not suitable for :: super flat screen display. No, as the field emission source of the display, it is not to be stable and reliable for long-term use, but more importantly, the field emission ^ current density needs to be at least 0.1 lmA / _2, which is enough to produce sufficient: And uniformity, and of course the electric field strength required to achieve the above-mentioned current is of course as low as possible, preferably below 25 V ///. in 0 For the above-mentioned conventional technology, due to the electrical measurement characteristics of the CNT field emitter (that is, the current density versus the electric field strength mapping ~ the number of bare carbon nanotubes and fixed to the cathode = general =; such as: above The CNT field emission cathode does not pay special attention to, and the current density is very small, unless extremely high voltage is applied, please refer to Figure 2: Processing diagram. The curve 11Q in the figure is made by the above-mentioned f technique, and is used for electrical measurement.
480537 五、發明說明（3) ! ! 得到的電場強度和電流密度的關係圖。其大小由圖所示即 使至接近6 V /// m的電場強度，其電流密度雖有上升但仍 不到0 . 0 1 m A / mm 2。可以預見欲達到0 · 1 - 1 m A / mm之電流密 度’電場一定要更南才行。 因此，習知技術，就發明人之知識了解，尚未有人發 | 明低電場強度，例如6 V/// m，就可達到上述至少所需電流 I 密度的奈米碳管場發射顯示器。美國專利第5，6 1 6，3 6 8由 J i η等人所獲得的專利則報導應用經電漿活化的鑽石超微 粒製作場發射顯示器可以有效改善在他的專利之前案。報 0 導中指出，鑽石超微粒具有很負的電親和性，因此，可以 | 在低電壓下就達到讓鑽石超微粒產生場發射的效果，J i η 等人指出，典型之ρ型半導體鑽石必須要達到70V//Z πι的 電場強度，其電流密度才上升至0 . 1 m A / m m 2。而他的發明 係應用鑽石超微粒製作可以將電場強度降至不到1 2 V/// m 甚至可低達5 V/// m，即可達做為顯示器之最小電流密度要 求。 J i η等人的方法至少包含係將5 - 1 0，0 0 0 n m的鑽石超微 粒粘貼在基板上之前，先以超過3 0 0°C的溫度以含氫的電 · 漿處理，並且以高速流動的氣體注入以避免鑽石超微粒粘 著成一團。此外並使得鑽石超微粒中石墨或者非晶型碳表 面積體積百分率小於1 0 %，並且愈少愈好。隨後，再將鑽 石超微粒和粘著劑混合再網印於預設含導電帶的基板上，480537 V. Description of the invention (3)!! The relationship between the electric field intensity and the current density is obtained. Its size is shown in the figure, even if the electric field strength is close to 6 V /// m, although its current density has increased, it is still less than 0.01 m A / mm 2. It is foreseen that the electric field density to reach a current density of 0 · 1-1 m A / mm ’must be further south. Therefore, according to the knowledge of the technology, as far as the knowledge of the inventors is concerned, no one has yet discovered that a low electric field strength, such as 6 V /// m, can achieve the above-mentioned nanometer carbon tube field emission display with at least the required current I density. U.S. Patent Nos. 5,6 1 6,3 6 8 and patents obtained by Ji et al. Reported that the use of plasma-activated diamond ultrafine particles to produce field emission displays can effectively improve his prior patent case. Guide No. 0 pointed out that diamond ultrafine particles have a very negative electrical affinity. Therefore, it is possible to achieve the effect of field emission of diamond ultrafine particles at a low voltage. Ji η et al. Pointed out that a typical rhodium semiconductor diamond It is necessary to reach an electric field strength of 70V // Z π before its current density rises to 0.1 m A / mm 2. And his invention is that the application of diamond ultra-fine particles can reduce the electric field intensity to less than 12 V /// m or even as low as 5 V /// m, which can reach the minimum current density requirement of the display. The method of J η et al. Includes at least a method of bonding diamond ultrafine particles with a diameter of 5-10,0 nm to a substrate, and then treating them with a hydrogen-containing plasma at a temperature exceeding 300 ° C, and The gas is injected at a high speed to prevent the diamond ultrafine particles from sticking together. In addition, the surface area volume percentage of graphite or amorphous carbon in diamond ultrafine particles is less than 10%, and the less the better. Subsequently, the ultra-fine particles of diamond and the adhesive are mixed and screen-printed on the substrate containing the conductive tape.
第6頁 480537 五、發明說明（4) 再以低於5 0 0°C的溫度硬烤燒結。 發明人有鑑於奈米碳管之習知技術尚未有效改善方 法。除非改用上述之鑽石超微粒，即便是如此，前案系在 未與粘著劑混合前以流動的氣流避免產生團塊，但並不能 確保與粘著劑混合成漿料（s 1 u r r y )再燒結時是否仍然使每 一鑽石超微粒產出預定之發射源的效果。因此，本發明則 提出一種更簡單而有效改善習知之奈米碳管顯示器之處理 方法，不但可以媲美J i η等人所提出之鑽石超微粒場發射 顯示器，且方法、及成本更低。 發明目的及概述 本發明之目的係提供一種簡易但顯著改善奈米碳管場 發射效率之方法。 本發明揭露了一種增強奈米碳管場發射電流密度之方 法，該方法至少包含以下步驟：首先網印奈米碳管漿料於 具有已圖樣化的陰極導電區之陰極基板上，以形成複數個 奈米碳管層像素區塊。接著對陰極基板施以低溫（約 5 0 - 2 0 0°C )軟烤處理，以去除揮發性溶劑，接著再對陰極 基板施以3 5 0至5 5 0°C燒結處理；及最後利用一表面處理附 著性膠膜（a d h e s i v e f i 1 m )於陰極基板上緊密貼合後即剝 離除去之，用以去除燒結後雖留在奈米碳管發射層表面上 480537 五、發明說明（5) 但卻粘結性鬆散的奈米碳管及拉起粘結性強但平躺在表面 上的奈米碳管。利用本發明可以顯著增加有發射電子效果 之奈米碳管數目，且不但場發射之電流密度明顯提升，均 勻度及亮度都可顯著增加。 發明詳細說明 有鑑於習知的奈米碳管發射器的製程技術，通常需要 極高的電場強度，而以鑽石超微粒，雖也可在較低電場下 提高電流密度，但需借助複雜的步驟，且由於是在未混合 成漿料前以氣流及電漿處理，網印及燒結後則並未再處 理，效果將會打折扣。因此，發明人提出一種表面處理技 術，方法簡單，但效果非常顯著。 發明人研究發現，以簡單的網印，軟烤及燒結步驟， 不能獲得所要的電流密度有幾個原因：其一是多數的CNT係 被埋入C N T層中，並未裸露出來或平躺在表面上，因此’ 對電流密度不產生貢獻。另一原因是C N T層之表層C N T對電 子發射層中的導電物粘著性較弱，即與銀的接觸不佳，故 其接觸電阻較大，需較大的操作電壓。且在電場驅動下即 易被吸離CNT層而造成電流密度的降低。為此，發明人提 出的方法，有以下幾種： 以一較佳的實施例而言，係一如發明背景所述的進行 480537 五、發明說明（6) CNT漿料的網印，將CNT-paste網印於陰極基板的條狀险極 上，此陰極之寬度大小約1 5 0 - 3 0 0 // m，而間距約5 〇 — 1 5仏 m。而網印後C NT的單一像素約0 · 0 2 - 0 · 〇 9 mm 2。軟烤溫产約 5 0 _ 2 0 0 C進行’用以將C N T聚料中的溶劑揮發並固化成〒 於陰極基板上。之後，以一貼附膠膜（adhesive f n m 丄丄丄m j仿,j 如具有粘著性的膠膜或者是具有靜電吸附性的薄膜，利用 具有滾輪的壓膜機（laminator)以一拉膠膜和壓著同時進 行的方式，將膠膜緊密貼附在已軟烤後的CNT層上，進行 第一次表面處理，將附著性不佳的物質先行移走（以下问 程taping處理）。此外被埋入在漿料内的CNT，也可以因曰為 t a p i n g過程而被拉起來。 ” 隨後’再以3 5 0 - 5 5 0°C進行燒結處理 $70、、、n後再次以 靜電薄膜或膠膜貼附在CNT層上，用以增加裸露在CNf emitter layer上之CNT的數目。上述的膠膜或靜電薄 了以具滾軸的壓片機進行貼附與剝離程序外，也可以、: 刮片刮壓、壓板整面壓模等等的方法將膠膜緊密貼附‘ 極上二其:上述燒結後的taping處理對電流密度增二 獻顯者且咼於軟烤後再taping處理，因此 = 處理這步驟可以是選擇性的。 俊的taping (如曲線1 1 0所示）和施以 兩者在電性上的差異。 M m的電場強度下電流密 圖二係比較未進行表面處理 本發明方法（如曲線1 2 〇所示）後， 圖一中曲線12〇(已處理者）在5V/Page 6 480537 V. Description of the invention (4) Hard roasting and sintering at a temperature lower than 500 ° C. The inventors have considered that the conventional technology of nano carbon tubes has not effectively improved the method. Unless the above-mentioned diamond ultra-fine particles are used instead, even so, the previous case was to avoid the formation of agglomerates with a flowing air flow before mixing with the adhesive, but it was not guaranteed to mix with the adhesive to form a slurry (s 1 urry) Whether each diamond ultrafine particle still produces the effect of a predetermined emission source during resintering. Therefore, the present invention proposes a simpler and more effective method for improving the conventional nano carbon tube display, which is not only comparable to the diamond ultrafine particle field emission display proposed by Ji et al., But also has a lower method and cost. OBJECTS AND SUMMARY OF THE INVENTION The object of the present invention is to provide a simple but significant method to improve the field emission efficiency of nano carbon tubes. The invention discloses a method for enhancing the field emission current density of a nano carbon tube. The method includes at least the following steps: first, screen printing the nano carbon tube slurry on a cathode substrate having a patterned cathode conductive region to form a plurality of Pixel block of nano carbon tube layer. Next, the cathode substrate is subjected to a low-temperature (about 50-200 ° C) soft baking treatment to remove volatile solvents, and then the cathode substrate is subjected to a sintering treatment at 350 to 55 ° C; and finally used A surface-treated adhesive film (adhesivefi 1 m) is peeled off after being closely adhered to the cathode substrate, and it is used to remove the sintering, although it remains on the surface of the nano-carbon tube emitting layer 480537 V. Description of the invention (5) But Loosely adhered carbon nanotubes and nano carbon tubes with strong adhesion but lying flat on the surface. The invention can significantly increase the number of nano carbon tubes with the effect of emitting electrons, and not only the current density of field emission is significantly improved, but the uniformity and brightness can be significantly increased. Detailed description of the invention In view of the conventional process technology of nano carbon tube emitters, usually a very high electric field strength is required. Although diamond ultrafine particles can also increase the current density at a lower electric field, complex steps are required. And because it is treated with airflow and plasma before it is mixed into a slurry, it is not processed after screen printing and sintering, and the effect will be compromised. Therefore, the inventors have proposed a surface treatment technology, which is simple in method but very effective. The inventor's research found that there are several reasons why the desired current density cannot be obtained with simple screen printing, soft baking and sintering steps. One is that most of the CNT systems are buried in the CNT layer and are not exposed or lying flat. On the surface, therefore 'does not contribute to the current density. Another reason is that the surface layer CNT of the CNT layer has weak adhesion to the conductive material in the electron emission layer, that is, the contact with silver is not good, so its contact resistance is large and a large operating voltage is required. And under the electric field driving, it is easy to be sucked off the CNT layer and cause the current density to decrease. To this end, the inventor's method has the following methods: In a preferred embodiment, 480537 is performed as described in the background of the invention. V. Description of the invention (6) Screen printing of CNT paste -paste is screen-printed on the strip-shaped poles on the cathode substrate. The width of this cathode is about 15 0-3 0 0 // m, and the pitch is about 50-15 mm. The single pixel of C NT after screen printing is about 0 · 0 2-0 · 〇 9 mm 2. The soft roasting temperature is about 5 0 _ 2 0 0 C. The process is used to volatilize and solidify the solvent in the CN T polymer to form on the cathode substrate. After that, an adhesive film (adhesive fnm 丄 丄 丄 mj imitation, j such as an adhesive film or a film with electrostatic adsorption) is used to pull the film with a laminator with a roller. At the same time as pressing, the adhesive film is closely adhered to the soft-baked CNT layer, and the first surface treatment is performed, and the substance with poor adhesion is removed first (taping process below). The CNTs buried in the slurry can also be pulled up because of the taping process. "Then 'sintered at 3 50-5 50 ° C for $ 70, and then again with an electrostatic thin film or Adhesive film is attached to the CNT layer to increase the number of CNTs exposed on the CNf emitter layer. The above-mentioned adhesive film or static electricity is thinned and attached to and peeled off by a tablet press with a roller. Alternatively, : Squeegee scraping, pressing the entire surface of the mold, etc., to adhere the film tightly to the pole. Second: the above-mentioned sintering taping treatment increases the current density by two people and shows that it is soft-baked before taping treatment Therefore = processing this step can be optional. Jun's taping ( (Shown as curve 1 10) and the difference in electrical properties between the two. After the current density map of the M m field is compared to the second series without surface treatment, the method of the present invention (shown as curve 1 2 0), In Figure 1, the curve 12 (processed) is at 5V /
480537 五、發明說明（7) 度高達1 0 m A / cm2，未處理者低於1 m A / cm2，因此可見本發 明的方法具有極為顯著效果。此結果可以以掃描式電子顯 微鏡觀察C N T層比較兩者之差異。圖三係未施以表面處理 者，圖四係已施以表面處理者。由圖中可以發現，將經過 taping處理者，CNT層比未經過taping處理之CNT層薄， 主要是應用本發明的tap i ng處理方法，可以將附著性不 佳的表層物質去除。此外’原先不具方向性的C N T ’更可 以因為t a p i n g過程而被拉起來垂直於陰極，而更具方向 性。 本發明具有以下優點： (1 )步驟簡單，且低成本，但增強CNT破管在CNT-FED 之場發射效果則十分顯著 (2 )粘貼膠膜之步驟簡易，容易控制膠膜貼附的參數 條件。 以上所述僅為本發明之較佳實施例而已，並非用以限 定本發明之申請專利範圍；凡其它未脫離本發明所揭示之 精神下所完成之等效改變或修飾，均應包含在下述之申請 專利範圍内。480537 V. Description of the invention (7) The degree is as high as 10 m A / cm2, and the untreated one is lower than 1 m A / cm2. Therefore, it can be seen that the method of the present invention has extremely significant effects. This result can be compared with the CNT layer by scanning electron microscope. Figure 3 shows those without surface treatment, and Figure 4 shows those with surface treatment. It can be found from the figure that the CNT layer that is subjected to taping treatment is thinner than the CNT layer that has not been subjected to taping treatment. The tap ing treatment method of the present invention can be mainly used to remove surface substances with poor adhesion. In addition, 'C N T', which was originally non-directional, can be pulled up perpendicular to the cathode because of the t a p i n g process, and more directional. The invention has the following advantages: (1) the steps are simple and low cost, but the effect of enhancing the field emission of the CNT broken tube in the CNT-FED is very significant (2) the step of attaching the adhesive film is simple, and it is easy to control the parameters of the adhesive film condition. The above are merely preferred embodiments of the present invention, and are not intended to limit the scope of patent application for the present invention; all other equivalent changes or modifications made without departing from the spirit disclosed by the present invention shall be included in the following Within the scope of patent application.
第10頁 480537 圖式簡單說明 本發明的較佳實施例將於往後之說明文字中輔以下列 圖形做更詳細的闡述： 圖一顯示奈米碳管場發射顯示器之陰極結構的示意 圖。 圖二顯示比較未進行t a p i n g表面處理和施以t a p i n g 後，兩者在電性上的差異。 圖三顯示奈米碳管結構經燒結處理但未經t ap i ng後之 一像素以掃瞄式電子顯微鏡觀察的橫截面圖。 圖四顯示奈米碳管結構經燒結處理且經t a p i n g後之一 像素以掃瞄式電子顯微鏡觀察的橫截面圖。 1Page 10 480537 Brief description of the drawings The preferred embodiment of the present invention will be explained in more detail in the following explanatory text with the following figures: Figure 1 shows a schematic diagram of the structure of a cathode of a carbon nanotube field emission display. Figure 2 shows the difference in electrical properties between the surface without t a p i n g and t a p i n g. Fig. 3 shows a cross-sectional view of a pixel of a carbon nanotube structure after sintering treatment but without tap ing. Figure 4 shows a cross-sectional view of a nano-carbon tube structure after sintering and one pixel after t a p i n g is observed with a scanning electron microscope. 1