智慧型模仁的初步開發

Abstract

微成形是經由射出成形、反應射出成形或熱壓成形等技術來量產塑膠微結構。由於在充模成形後，模具降溫至開模溫度時材料會因為模仁快速降溫而產生收縮，對模穴會有充填不完全的情形發生，因而造成成形品轉印性不佳的缺陷。為了改善這種情況，希望在模具降溫到開模溫度時模仁能保持適當的高溫，因此本研究以製作智慧型模仁為目的，採用半導體的各項相關製程，利用P型（100）之矽晶片為基材當作模仁，在其中製造出有適當阻值、能導電的區域，同時引入熱電阻的觀念，對導電區域通入電壓或電流，讓導電區域能夠導通並產生熱量，作為熱壓完成後降溫開模時模仁維持溫度的來源。再者，並探討導電區域阻值與溫度及阻值與壓力的關係，期能發展出『嵌入式壓力、溫度感測器』，以便實際感測模仁的溫度、壓力，達到即時監控溫度、壓力的目的，如此有助我們提高脫模後的成形品的品質。 由實驗結果得知，保持適當的高溫可以有效改善轉印性。同時溫度越高，導電區域阻值有下降的趨勢；壓力越高，導電區域阻值亦有下降的趨勢。

Micro molding is a technology of replicating plastic microstructure by injection molding, reaction injection molding, and hot embossing. In these various processes, shrinking of polymer material in the cooling stage may lead the mold cavities to be filled incompletely. This causes the defect of bad shape-transformation. To improve this situation, keeping the mold insert at a satisfactory high temperature while the mold is cooling down seems to be a useful solution. This research attempt to develop an intelligent mold insert for above purpose. Semiconductor processes are employed and P type (100) silicon wafer is used as the substrate to produce conducting regions with desired resistance. Then these conducting regions with suitable resistance are utilized as the heaters, charged an electric current, to heating the mold insert in the cooling stage. Furthermore, effects of temperature and pressure, respectively, on the resistance are investigated for the creating of temperature-sensing and pressure-sensing function on the mold insert. From the results, keeping suitable high temperature can improve the shape-transformation of microstructures. And for higher temperature and higher pressure, the resistance of conducting area will decrease.