• Categories:Industry News
• Author:Becky Su
• Origin:
• Time of issue:2023-02-08 11:13
• Views:

(Summary description)SMT Quality Terminology 1、The ideal solder joint   Good surface wettability, that is, the molten solder should be spread on the surface of the metal being soldered and form a complete, uniform and continuous solder coverage layer, the contact angle of which should be no greater than 90.    The correct amount of solder, the amount of solder is sufficient but not too much or too little    Good soldering surface, the surface of the solder joint should be complete, continuous and rounded, but does not require a very shiny appearance.    Good solder joint position component's solder end or pin on the pad position deviation within the specified range. 2、No wetting    The solder on the solder joint and the soldered metal surface to form a contact angle greater than 90 degrees. 3、Open soldering    After soldering, the pads are separated from the PCB surface. 4、Drawbridge (drawbridging)    One end of the component leaves the surface of the solder pad to the upper diagonal or upright, also known as the tombstone (Tomb stone). 5, bridging    Two or more should not be connected between the solder joints connected to the solder, or solder joints of the solder and adjacent wires connected. 6、False soldering    After soldering, the solder end and the pad between or between the pins and pads sometimes appear electrical isolation phenomenon 7、Pull tip    Solder joints appear in the solder has a prominent outward burr, but no contact with other conductors or solder joints 8、Solder ball (solder ball)    Soldering adhered to the printed board, negative solder film or conductors on the solder ball, also known as tin beads. 9、Holes    Solder holes of varying apertures 10、Position shift (skewing )    Solder joints in the plane lateral, longitudinal or rotational direction deviation from the intended position. 11、Visual inspection method (visual inspection)    With the aid of a 2-5 times magnifying glass illuminated, the quality of PCBA solder joints is inspected by visual observation. 12, after welding inspection (inspection after aoldering)    PCB quality inspection after completion of welding. 13、Reworking (reworking)    To remove local defects in the surface assembly components of the repair process. 14、Placement inspection ( placement inspection )    Surface mount component placement or after completion, for whether to miss paste, misalignment, paste wrong, damage and so on the situation of quality inspection.