文档介绍：1/ 14 A Accelerated stress test A test designed to stress the application until failure. Acceptable Quality Level AQL. The maximum allowable number of defects per 100 units. Accuracy The ability to reach the target. Acoustic Microscopy A test method using ultrasonic sound to produce high resolution images. Activator A chemical substance used to improve the ability ofa flux to ponent and PCB surfaces for oxides and conta- minants. ponent that actively can change an electrical applied signal. Such as transistors and IC's. Adhesive A substance used to hold two materials together. SMT adhesive is used to ponents from placement until wave soldered. Conductive adhesive is used to form a mechanical and electrical connection as an alternative to soldering. Ag Chemical symbol for silver. Metal with atomic No. 47. Used as protective layer ponent terminals, PCB solder pads and in some solder alloys. Air Knife Unit blowing air towards an object ina thin straight line. . used in wave soldering machines to remove excess flux from the PCB. Algorithm A specification of actions solving a task. Alloy A material made by melting two or more metals together. Alumina White substrate material used primarily in thick film applications. Antimony Sb. Semi-metallic with atomic No. 51. Used in some solder alloys. Antistatic Material Partly conductive material resisting rapid static charging. AOI Short for A utomatic O ptical I nspection. Unit inspecting solder paste print or soldered PCB's. Aperture Opening ina metal stencil or mesh screen. Aperture file(s) Computer file(s) containing X,Y coordinates, shape and aperture sizes used in the stencil manufacturing process. AQL Short for eptable Q uality L evel. The maximum allowable number of defects per 100 units. Aqueous Water soluble. Archimedes Pump Or auger pump. Dispensing unit using an auger to force the adhesive onto the PCB. Aspect Ratio Stencil thickness to the width of the smallest aperture or PCB thickness to the diameter of the smal