Study On Offline 3D Solder Paste Inspector

Now , the microelectronic packaging is heading for high density and high integration. The pins pitch are more and more narrow. This trend demands SMT factories improve their inspection device to suit fine pitch soldering. In order to satisfy the fine pitch soldering demand and make sure solder joint's reliability, we must control the paste's height and volume, printed on the pad. At present, most offline solder paste inspections used in the factories are 2D laser inspection. They can measure the solder paste's height, but they can't accurately measure the volume. So 2D solder paste inspection can't satisfy the factories'demand, they need a 3D solder paste inspection to tell them accurate volume.In this research we will develop a offline 3D solder paste inspection. This device can accurately measure solder paste's height and volume. It contains SPC software, so you can record solder paste data, then draw control chart. This device's cost less than a half of overseas'.Firstly, we research laser trigonometry measurement principle. The laser trigonometry measurement method can be classified as normal incidence and oblique incidence. Because this device demands 3D measurement, we choose laser normal incidence and CCD oblique receiving. Secondly, we introduce work principle and structure of CCD. The relationship between resolution and CCD's cell size is discussed. The cell size of this device's CCD is 4.65μm×4.65μm. This device need a small, low power and safe laser source, so semiconductor laser source is the best choice. It produces a laser point, then this point is changed into linear laser by a column prism. The width of linear laser is less than 100μm. Based on above analysis, the light trace is designed and 3 dimensional coordinate equation of measured point are set up. Servo motor and raster ruler are used to control the X-Y table's movement precision under 3μm. The structure of software is researched. VC++6.0 is chosen as development tool. ADO method is chosen to visit data base. Access2003 is chosen to make data base. In order to reduce code, Using VC++...