環狀烯烴聚合物之流變、抽絲及電路板基材應用研究

本論文研究分為三個部份。低介電常數(Dielectric Constant)電路板之應用，尚屬創新。目前印刷電路基板均是以玻璃纖維為基材，但在微影技術不斷細化下，玻纖的介電係數為進一步細化的瓶頸。因此擬用與玻纖同為非晶材料的環狀烯烴聚合物，因其理論介電係數較玻纖低一倍。第一部份，以環狀烯烴聚合物紡絲為主。環狀烯烴聚合物 (metallocenebased cyclic olefin copolymer； mCOC)的熔融紡絲製程從未被成功開發。實驗結果顯示，最佳的mCOC熔融擠壓溫度在320℃∼330℃間。由於環狀硬鏈的存在，使得mCOC之Tg點較線性烯烴類如PE、PP等，高出甚多，熔融延伸時極易固化。傳統PP熔融紡絲時所使用溫度18℃冷卻降溫製程，對mCOC而言並不適用。實驗得知，mCOC熔紡時，需使用溫度180℃，長1.4m之保溫及延遲冷卻熱板設計，使整體延伸區溫度超過mCOC之Tg點，方可順利將熔融mCOC延伸成絲。成絲速率以1500m/min最佳。此時mCOC熔融延伸倍率達90，雖高於文獻值10，但仍遠小於一般線性高分子200-400之範圍。與線性聚烯烴的PP比較，mCOC的環烯烴硬鏈立體障礙，對shear rheology未有明顯影響。但卻會嚴重影響elongation rheology行為。此外，實驗結果建議在纖維捲取前，需搭配200℃及延伸倍率1.15的固態延伸製程，可得到最佳的纖維強度(1.41g/den)。複折射率之結果顯示， mCOC雖經抽絲及延伸，並未能產生總體順向。纖維進一步經由X ray繞射及DSC熱分析後，暗示mCOC在固態熱延伸下，環烯烴間軟鏈會產生局部微結晶(約6.5 nm)，且結晶度隨延伸羅拉溫度的升高而略為增加。第二部份，探討環狀烯烴聚合物纖維的織造性，以漿紗及包紗為主，最佳的包芯紗撚係數為2.5TPI(twist per inch)，纖維強度3.11 g/d，此時紗線的殘餘扭力為104 note/m。由於包撚的鞘紗存在，使得mCOC包芯紗之強度較一般漿紗之mCOC纖維，高出甚多，而漿紗所生產的mCOC纖維因纖維強度只有2.12 g/d不足以當經紗。第三部份：與傳統的玻纖布壓制而成的CCL板比較，mCOC布壓制而成的CCL板有較優良的電性質，隨著mCOC布的含量及位置會對介電常數(Dielectric Constant ； DK)及電子逸散(loss tangent； Df) 造成不同程度的影響，經實驗結果建議mCOC布附著在CCL板的兩側會有優秀的DK值2.9，隨著mCOC布比例的增加會有微幅下降但不明顯，只有0.2的差距。而影響Df值的主要原因又與位置無關，是mCOC布的含量比例影響較大，並且會有明顯的差鉅，從0.035下降至0.007，經分析後應發現mCOC布對DK會產生阻擋效果，只要最外側就可以達到效果。

關鍵字

環狀烯烴聚合物；熔融紡絲；延遲冷卻；包芯紗；介電常數

並列摘要

There are three parts to this thesis. It is an innovation of low dielectric constant in circuit board’s application. Currently, glass fiber is used for the circuit board’s base material. In the process of micronizing the micro-photo technology, the high dielectric constant of the glass fiber becomes the bottleneck of his technology. Similar non-crystal material, metallocenebased Cycling Olefin Copolymer (mCOC) is considered to replace glass fibers. The theoretical dielectric constant of mCOC is a half of the glass fibers. This first part discusses the spinning of mCOC, the melt spinning process has never been developed successfully. From the experiment shown, the ideal melt spinning temperature of mCOC is around between 320°C - 330°C. The existence of the cyclic hard chains makes the glass transition temperature (Tg) point of the mCOC much higher than the linear olefin’s, such as polyethylene (PE) or polypropylene (PP) etc. It is easily solidified during the hot melt drawing process. Traditionally, we use an 18°C quenching process for spinning PP fibers, however this does not work for mCOC. We found that a temperature of 180°C is required. Then, we used a 1.4 m long heating board with an insulation to prolong the cooling time of the drawing zone. This device makes the temperature of the drawing zone higher than its Tg point. Using this type of design, it allows spinning mCOC fibers to be smoother. The best spinning speed used was 1,500M per min. With this spinning speed, the melting draw ratio is 9 folds higher than the documented 10 times. This is still much lower than the linear olefin, which draw ratio is about 200-400 folds. Additionally, it has been shown that the 3-D hurdle of hard chain mCOC does not have any significant influence to its shear rheology when compared to linear olefin PP, but it will significantly influence its elongation rheology behavior. In addition, the results of the experiment suggest that an extra drawing process at 200°C and 1.15 draw ratio will help to obtain optimal fiber tenacity of 1.41 g/den. The multiple refraction index of the fiber shows that even though mCOC fibers have been spun and drawn, they are not fully oriented during processing. By using X-ray diffraction and Differential Scanning Calorimetry (DSC) heat analysis, we show the soft chains within the mCOC will have partial micron crystallization (about 6.5nm). This is created during the mCOC fibers undergoing hot drawing within the solid state. Its crystallization degree will be slightly increased when raising the temperature of the drawing godet roll. Secondly, we investigate the weaving capability of mCOC fibers in the form of sizing yarn and covered yarn. The optimal covering yarn twist index is 2.5 twist per inch (TPI), with 3.11g/d tenacity of fiber, resulting in the remaining torque of yarn measuring 104 note/m. Regular mCOC sizing yarn has a tenacity of 2.12g/d, which is insufficient to be used as warp. The additional warping yarn on the mCOC covering yarn allows it have a higher tenacity than regular mCOC sizing yarn. Lastly, the third component of this study is the use of mCOC fabric in CCL boards. Using mCOC fabric in the design of CCL boards provides enhanced dielectric properties in comparison to traditional CCL boards composed of glass fabric. Based on the ratio of mCOC fabric and the location on the CCL board, the dielectric constant (Dk) and electron loss tangent (Df) may have varied influences. We show that when mCOC fabric coated on both sides (top and bottom layers) of the CCL board a Dk value of 2.9 can be obtained. However, when the ratio of mCOC fabric is increased, the D k value will slightly decrease down to 2.7. It is noted that the location of the mCOC fabric on the CCL board does not influence the value of Df. On the contrary, the ratio mCOC fabric contained in the CCL board has more influence of the value of Df. When this ratio is increased, the Df value decreases a 100-fold from 0.035 to 0.007. Given these findings, mCOC fabric can inhibit the Dk effectiveness and is suitable to be placed on the outer layers of the CCL board.

並列關鍵字

Cyclic Olefin Copolymers ； Melting Spinning ； Delay Quench ； Single Cover Yarn ； Dielectric Constant

參考文獻

[1-1] Ronald R.〝CYCLIC OLEFIN COPOLYMERS,〞ADVANCED MATERIALS & PROCESSES, MARCH 2001 pp.23-27.

[2-1] Delsemme AH. The chemistry of comets. Phil Trans Roy Soc Lond 1988; 325: pp. 509–523.

[2-2] Lamonte R and McNally D. Uses and processing of cyclic olefin copolymers. Plast Eng 2000; 56: pp. 51–55.

[2-3] Kaminsky W, Bark A and Arndt M. New Polymers by Homogenous Zirconocene/Aluminoxane Catalysts, Macromol.Symp., 1991; pp.47: 83.

[2-7] C.D. Han, Rheology in Polymer Processing, Academic Press, New York, 1976, pp. 35-41

國際替代計量

環狀烯烴聚合物之流變、抽絲及電路板基材應用研究

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