Our SMT Process
Step 1 – Printing
Our SMT Assembly Process starts with the solder paste printing process. The printing process is one of the most important steps. It is imperative to have a good print to produce defect free assemblies right out of the re-flow oven. Our stencil printer is fully automatic and precise for fine pitch down to 0.3mm (12 mil). The machine is equipped with a universal frame holder so we can easily use customer supplied legacy stencils of all shapes and sizes. Our machines also perform solder paste inspection.
Step 2 – SMT Pick and Place
The second step in the process is pick and place. After the machine is programmed and loaded, our pick and place machines can place parts as small as 01005 and 0.3mm pitch (12 mil). Our machines can place upwards of 10,500 components per hour and are equipped with Cognex vision systems. We can handle tape and reel, trays, tubes, and even cut tape. Our feeders are smart as they know what component is loaded and where they are on the machine.
Step 3 – Oven
The third step in the process is re-flow. A proper re-flow profile is another imperative characteristic to produce defect free assemblies. Our re-flow oven contains independent upper and lower PID temperature controls for each heat zone and three thermocouple inputs for accurate “leaded” and “lead-free” temperature profiling.
Step 4 – Inspection
The fourth and final step in the surface mount process is inspection. Every assembly is built to IPC-A-610 standards. Our production manager is a certified IPC trainer and all other assembly staff are trained internally as IPC operators. Inspection starts out using our state of the art automatic optical inspection (AOI) machine.
The AOI machine checks solder joints, part markings, part orientation, and missing components. It has two top-down viewing cameras to support inspection of small components down to 01005. The machine can even check the color of those pesky capacitors which do not have part markings. After inspection, the machine prints a report that matches the serial number of the assembly showing any defects right on the image of the PCB. A trained IPC operator must then check the suspected defect under a high power microscope to confirm or accept. X-ray is used to inspect for components where solder joints are not visible such as BGAs.