薄型化導光板雙面微結構熱壓成型的翹曲分析

Warpage and process analysis of thin type LGP with double side microstructure

力秉暉(Ping-Hui Li)

指導教授 ： 張致遠

國立高雄應用科技大學/工學院/模具工程系/碩士(2017年)

摘要

傳統塑膠射出成型在製作薄型化與大面積的導光板元件時，經常面臨模穴薄、流動面積大與雙面微結構成型不良的問題，因而導致生產良率低、雙面微結構轉寫率不均、產品翹曲變形等技術瓶頸。
因此，本研究改採開放式與上下模可變溫度的熱壓成型法來製作超薄化的導光板元件，以不同熱壓溫度、作用壓力與持壓時間等參數的變化，利用DOE實驗計畫法找出影響翹曲之顯著因子，並藉由數據統計分析取得較優化的製程参數，來探討此薄型化產品的雙面微結構成型與翹曲問題，然後提出改善建議，再以田口實驗法找到最適化條件的製程參數來最佳化導光板元件的品質。
研究結果發現，熱壓溫度與壓力是影響導光板元件品質的關鍵因素，隨著溫度與壓力的增加，雙面微結構圖案的轉寫性有非常明顯的提升，但當熱壓溫度與持壓溫度有明顯落差時，則壓印基材會因受熱不均與收縮不均的因素，而促使整體導光板元件的翹曲變形問題也變得嚴重，在透過上下模溫可變的製程控制下，將可使熱壓印所產生的殘留熱應力能夠均勻釋放，並讓薄型導光元件能得到最好的雙面微結構轉寫率，而且其成品翹曲量也可在導光元件的設計範圍內。

關鍵字

熱壓轉印 ； 微結構 ； 薄型化導光板 ； 轉寫性 ； 翹曲

並列摘要

Conventional plastic injection molding often encounters problems such as thin mold cavities, large flow area and poor double-sided microstructure in the production of thin and large-area light guide plate components. This results in technical bottlenecks like low production yield, uneven double-sided microstructure transcription rate, and product warping deformation.
Therefore, this study uses the open type and compression molding with upper and lower mold variable temperature to produce ultra-thin light guide plate components. Different parameters such as molding temperature, operating pressure and pressure-holding time were adjusted using the DOE experimental method to determine the significant factors that cause warpage. In addition, optimal process parameters were obtained by means of statistical data analysis to explore the problems of double-sided microstructure molding and warpage of thin products in order to find the best process conditions using the Taguchi experimental method and to make suggestions that optimize the quality of light guide plate components.

The results show that molding temperature and operating pressure are the key factors that affect the quality of light guide plate components. With the increase in temperature and pressure, the transcription rate of double-sided microstructure pattern increases very significantly. However, when the molding temperature and holding temperature significantly vary, the overall light guide plate components’ warping deformation problem becomes serious due to uneven heating and uneven shrinkage of base materials. The residual thermal stress generated by hot pressing can be released evenly through a variable process control of the upper and lower mold temperature; the thin light guide component can obtain the best double-sided microstructure transcription rate and the finished product’s degree of warpage can be set according to the design of the light guide component.

並列關鍵字

Microstructure ； DOE ； LGP

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