| 摘要: | 高精度的微細孔洞與微細槽，一直是微機電系統(MEMS)所追求的目標之一，而如何使用經濟的方法，來製造高精度的微細孔洞，則是本實驗所要研究的重點。整個實驗乃是利用複合加工或批次製造(Batch mode production)的方式，在金屬或玻璃上加工高精度的微細孔或微細槽，並且結合塑性成形加工，提高成品的製造效率。 在實驗的進行過程中，我們先用自行設計的工具電極研磨機構，修整出適當形狀與尺寸的工具電極，然後使用此一電極，以放電的方式，在金屬材料上鑽削一個微孔或凹洞，再使用超音波振動研磨或磁力研磨等的加工方法，對微細孔洞進行研磨拋光加工。在玻璃上的微孔加工，則是將修整完的工具電極，當成加工工具，然後結合超音波振動，在玻璃上鑽削微孔。另外在微細槽模具的加工中，則是利用組合式電極，在碳化鎢的薄板上，實施複數微細槽的放電加工；而加工後的微細槽模具，即可以結合壓製與刮製的加工方式，製造出微細散熱片。 在放電微孔的精度改善方面，結合微能量放電與超音波振動研磨，加工直徑100?m的微孔或邊長100?m的正方形微孔，若能在適當的磨料濃度、振幅、轉速與較慢的進給下進行研磨加工，則可以有效改善放電微孔的精度。研磨加工時，平直狀工具會有較佳的入出口孔徑差改善率，在適當的加工參數下，其改善率可達60%以上；而階級狀工具對表面粗糙度的改善效果，則比平直狀工具來得好。使用超音波加工在厚度500?m的玻璃上，鑽削直徑150?m的微孔時，若配合適當的磨料濃度、超音波振幅、轉速與較小的磨料濃度及進給率，可以加工出入出口孔徑差只有2?m的微細孔。結合微能量放電與微研磨的加工方式，可在直徑280?m的錐狀圓桿上，加工出直徑150?m的半球形凹孔，且利用磁力研磨，可以使放電邊緣變得光滑，且沒有毛邊附著，是一種製造高精度凹型微孔的有效方法。使用組合式銅箔電極，可使微細放電加工達到批次製造的目的，而所加工出來的超硬合金微細槽，藉著變形加工法，可加工出微細散熱片。而此種微細槽的放電加工，必須配合噴流加工方式，才可以得到較佳微細槽形狀。另外使用純水當放電加工液時，由於氧氣的助燃與電解作用，加快放電效應的進行，因此微細槽模具的加工速度可以比煤油快5倍，但因為電極磨耗較快，微細槽的形狀較不易控制。 High precision micro-holes and micro slits are an important target that can be made in the micro-electro-mechanical systems (MEMS). Therefore, the main purpose of this thesis is to develop an economical and effective method to produce high accuracy micro-holes and micro slits. A compound or batch mode method was introduced to our researches. Furthermore, the high precision micro-holes were successfully fabricated in the metal or glass by the compound method, and the batch mode method was an efficient method to manufacture a micro slit die. A micro heat sink can be made using micro slit die in the plastic deformation manner. In these experiments, an electrode was pruned to appropriate micro size by an electrical discharge grinding mechanism, first. Then a micro-hole or a semi-sphere concave hole in a metal plate was drilled using this electrode in micro EDM (MEDM). Finally, a micro ultrasonic grinding (MUG) or magnetic polishing was applying to burnish these micro-holes. Furthermore, the electrode was also utilized as a cutting tool when the micro-hole was fabricated by ultrasonic machining equipment in a small glass plate. In addition, an assembly electrode was used to make a micro slit die via MEDM in a tungsten carbide plate. Then combining with the pressing or scraping method, micro heat sinks could be produced applying the micro slit die. Combining with MEDM and MUG to fabricate the micro-hole with diameter 100 ?m or square lateral length 100 ?m, a high precision micro-hole would be obtained at appropriate abrasive concentration, ultrasonic amplitude, rotating speed and slow feed rate. The straight grinding tool had better precision improved rate of micro-hole between entrance and exit (PIREE) than the step grinding tool in the MUG process. PIREE would reach 60% at suitable ultrasonic parameters. However, the step grinding tool would get the good surface roughness. The micro-hole with thickness 500??m and diameter 150 ?m in the Pyrex glass was drilled by micro ultrasonic machining method (MUSM). The diameter difference between entrance and exit would reach 2 ?m if appropriate abrasive concentration, ultrasonic amplitude, rotating speed and slow feed rate were used. The semi-sphere micro-hole in taper thin rod with diameter 150 ?m could be manufactured, combining with MEDM and micro grinding process. The burr attached in the micro-hole edge could be removed and the thin rod outside surface would be smoothed by magnetic polishing manner. In addition, the batch mode production of micro slits die would be carried out by assembly copper foils in MEDM. The micro heat sink would be fabricated using micro slits die at plastic deformation machining. However, manufacturing of micro slits die in MEDM needed to cooperate with the dielectric flushing way to find the good micro fins shape. During the oxygen combustion-supporting and electrolytic effect, the MEDM efficiency would increased fast when the distill water was utilized as dielectric. The micro slit die fabricating speed in distill water would fast 5 time of the kerosene. The micro fin shape was not control easily in MEDM because of the fast electrode abrasion. |
