![]() It can be used by itself or combined with powdered solder alloy to form solder paste. Paste flux is used for precise flux application. ![]() Solid flux is most often found inside flux core solder wire. Flux comes in three forms: solid, paste, and liquid. Solder formation at the intersection of surfaces of a solder connection.Ĭenterline spacing of leads 0.5 mm (20 mils) or less.Ī material that cleans metal surfaces of absorbed gases, oxide films, and other surface contaminants. Ex: Sn63 Pb37 alloy melts and solidifies at 183° C (361° F). During soldering the gold is dissolved into the solder joint.Īn alloy composition where the alloy melts and solidifies at a single temperature. Surface finishing process of electroless nickel followed by immersion gold. The result is a distorted fillet with an irregular surface texture. The sugar has not reached its melting temperature, but readily dissolves into liquid water.Ī solder fillet that solidified while the solder joint was moving. This is like dissolving sugar into water. This is NOT a function of all the materials melting, but rather a dissolving of one material into another. The chemical change that takes place as solid materials dissolve into liquid materials. The removal of solder and components from a circuit, usually for purposes of repair.Ī condition where molten solder has coated a surface and then receded, leaving irregularly shaped mounds of solder separated by areas covered with a thin solder film. It requires a chemical reaction capable of dissolving the metal into a solution of metal ions, which are then redeposited by electro-migration in the presence of an electromagnetic field. IPC–TM-650 2.3.32: The test method designed to determine the removal effect the flux has, if any, on the bright copper mirror film, which has been vacuum deposited on clear glass.īranch or snowflake-like patterns of metal that grow on surfaces between conductors. Compacting during solder paste dispensing, can be observed in the dispense tip and all other sections of the flow path. Solder alloy in solder paste that has been compressed into a dense, low-flowing or non-flowing condition caused by repeated pressure cycles, flow restriction, vibration, and/or high temperatures. This is evident by poor wetting, a non-smooth surface, and/or a chalky or grainy appearance. The possible causes include too short contact time or low soldering temperature. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces.Ī solder connection that was made with insufficient heat. The ability of a liquid to flow in narrow spaces independent of external forces like gravity. The functional operation of components or assemblies, as a test for defects or failure prior to putting into use. The melting temperatures for brazing alloys range from 450° C (852° F) to 1100° C (2012° F).įormation of a solder alloy connection between two or more adjacent contacts.īare printed circuit boards that have had solder paste deposited and reflowed on the pads prior to component installation. Some typical brazing alloys include copper-zinc, copper-gold, copper-phosphorous, and silver-based alloys. Brazing differs from soldering by the melting temperature of the alloy (greater than 450° C for brazing and less than 450° C for soldering.)Īlloy used as the filler metal in the brazing process. BGA packages, and other area array packages, allow for higher connection counts and connection density than other surface-mount packages.Ī method of joining metals that involves the use of a filler metal or alloy that melts over 450° C (842° F) and below the melting temperature of substrate materials. tensile strength, melting temperatures).Ī surface-mount component with a grid of connection points on the bottom.Ī surface-mount component containing a processor, and sometimes additional components, where the bottom has a grid of connection points with solder balls attached. Generally, alloys will have different properties than those exhibited by their individual elements (e.g. Activator is consumed by heat over time.Ī substance composed of two or more metal elements. Activator cleans metal surfaces of oxides and contaminants, promoting wetting of Solder Alloy. The chemically reactive portion of a Flux. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
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