Abstract: An artificial bone plate unit and an assembleable artificial bone plate are provided. The artificial bone plate unit includes a plate body, multiple connecting pins, connecting holes, drug cavities, and drug-releasing openings. The plate body has two main surfaces and a peripheral surface connected between the two main surfaces. The connecting pins and the connecting holes are formed on the plate body and arranged along the peripheral surface on the plate body. The connecting holes correspond in shape to the connecting pins. The drug cavities are formed in the artificial bone plate unit and are connected to the drug-releasing openings. The artificial bone plate units are connected using the connecting pins and the connecting holes to form the assembleable artificial bone plate. The assembleable artificial bone plate can be bent into the shape of a defect area of the skull, which saves material and time.

Abstract: A wafer alignment system aligns a wafer by checking the alignment marks formed on the back surface of the wafer. A number of guiding rays are used to determine the corresponding alignment mark on the back of the wafer to ensure that the wafer is properly aligned. The alignment system of the invention also includes a wafer stage and a fixed base, wherein the wafer stage and the fixed base contains a number of apertures that allow the guiding rays to pass through and strike on the alignment marks on the wafer.