- 學位論文
黏結劑對於鈦酸鋇漿體流變行為及刮刀成型薄帶特性之研究
Effects of Binders on the Rheological Behaviors of BaTiO3 Slurry and the Properties of Green Tapes
摘要
隨著元件日趨於輕、薄、短、小及高功能方向發展，使得被動元件必須縮小化，尺寸精密度都受到嚴苛的考驗，因此必須邁向薄層化MLCC 製程上的開發。此階段的突破不僅能使尺寸縮小也能得到較高的電容儲存電能，製程上各階段控制因子都有可能對薄帶特性有所影響，找出製程的變因，並加以控制或取代，以得到最佳的製程參數，希望有利於業界的MLCC 產品開發。 本實驗主要是探討不同PVB 系統中，配合不同製程參數對漿料特性之影響，藉此開發薄層化的漿料配方。製程控制因子包括溶劑的選擇及配比、黏結劑的種類、分散劑與黏結劑關係等，這些製程參數都會影響漿料黏度、流變特性、球磨後粒徑大小及分佈，進而影響薄帶特性及生胚特性，如：生胚薄帶的粗糙度、厚度、彈性係數、機械性質、疊壓後生胚切割分散性。另外燒除(burn-out)後生胚黏結劑分佈情況和燒結後緻密性等，亦會受到影響。 實驗結果顯示，(1)當甲苯：酒精 = 60：40 之比例能有效提供研磨效率，並能穩定漿料黏度隨時間之變化，對於後續製程都有較佳的性質，如：減少表面粗糙度、薄帶下表面黏結劑分佈較均勻且有較小的微孔洞產生、具有不錯抗拉強度及伸長量、黏結劑燒除生胚觀察有較小的微孔洞及燒結後有較佳的生胚緻密度等特性。(2)用此溶劑比例進行雙黏結劑實驗，實驗結果顯示，B-4 低分子量高分子黏結劑的添加，能有效降低漿料黏度，並在流變量測分析顯示，有效降低高分子在漿體中，凝絮作用所產生觸變性(thixotropy)及降伏應力(yield stress)，有效提升漿體流動穩定性，將有助於薄層化製程的開發。
並列摘要
In recent years, the electronic components have developed into lighter, thinner, smaller and multi-functional entities. For the reason that, the passive components of MLCC should necessarily reduce in size, attempts were made to increase the volumetric efficiency and the best process parameters, that would be beneficial for the development and industrial production of MLCCs. The purpose of this study is to investigate the effects of different binder systems and different process paramenerts for slurry preparation that included the types and ratio of solvent, the types of binder and the relation between dispersants and binders. These will affect the slurry properties such as viscosity, rheological behavior, distribution of particle size and then influence the properties of green sheets and bodies, such as：toughness, thickness of dielectric, flexibility and mechanical characteristics. Furthermore, the morphology of green bodies observed after burning-out binder and sintering thus will also be affected. The results show that (1) the toluene and ethanol at a ratio of 60：40 can provide an effective milling efficiency, and the stability versus viscosity of slurry changes with time. With regards to results after processing, they have shown better properties, such as：reduction of the surface toughness of green sheet, homogeneous distribution of binder and distribution of micropores for the down surface, with good tensile strength and elongation, while the green bodies have been observed to contain micropores after binder burn-out and the better densification after sintering.(2) The above solvent ratio used to carry out experiments of double binder and the results there of showed that an addition of B-4 (lower molecular weight polymer binder), can effectively improve the viscosity of slurry. The rheological analysis shows that, it effective by reduces thixotropy and yields stress in the floc phenomenon, increasing the flow stability of slurry, and thus contributes to the development of thin film MLCCs.