Last week we finished the Surface Mounting Technology (SMT) process, a paramount progress of prototype PCB Assembly, in Seeed’s in-house Agile Manufacture Center.
We kicked off the pilot run of 200pcs in the morning. The first piece of PCB, which went through the whole process this morning, was programmed and passed the test plan around 11 am. It validated the components and function testing of pilot run. Then we switched machines in full speed to finish SMT process for the whole batch of production.
Here is a recap if you miss our #Arduboy #Live Twitter streaming. This week, we plan to finish the pilot run of 200 pieces of PCBA including testing and injection molding of mechanical parts. Stay tuned!
Step 1 Automatic Solder Paste Printing
— Seeed (@seeedstudio) January 13, 2016
Stencil printing is a critical first step in surface mount assembly. It is often cited that the solder paste printing operation causes about 50%-80% of the defects found in the assembly of PCBs. Printing is widely recognized as a complex process whose optimal performance depends on the adjustment of a substantial number of parameters. It is not uncommon to hear that stencil printing is more of an “art” than “science”. In fact, the process is so complex that sub-optimal print parameters usually end up being used. In addition, stencil printing produces relatively noisy data, which makes the print process extremely difficult to control. Ideally, minimizing the variance of the deposited location and volumes will improve the quality of the process and produce more reliable solder joints.
Step 2 Pick and Place Chips and Components
[Pick and Place Machine]
SMT (surface mount technology) component placement systems, commonly called pick-and-place machines or P&Ps, are robotic machines which are used to place surface-mount devices (SMDs) onto a printed circuit board (PCB). They are used for high speed, high precision placing of broad ranges of electronic components, like capacitors, resistors, integrated circuits onto the PCBs which are in turn used in computers, consumer electronics as well as industrial, medical, automotive, military and telecommunications equipment.
#1 Engineers entered the specs, such as position and direction, according the design file to pick and place for preparation.
#2Materials for #SurfaceMountingMachine comes in reels and plates on either side.
Step 3 Reflow Oven
A reflow oven is a machine used primarily for reflow soldering of surface mount electronic components to printed circuit boards (PCB). The oven contains multiple zones, which can be individually controlled for temperature. Generally there are several heating zones followed by one or more cooling zones. The PCB moves through the oven on a conveyor belt, and is therefore subjected to a controlled time-temperature profile.
#1 ReflowOven to melt solder pastes. 10 temperatures, about 5 meters long for different materials.
#2 Visual Inspection again to check outcome of #ReflowOven process.
#3 Reverse engineer by disassembling sample and solder the rest of components such as OLED, speaker and wires.
Step 4 Program and Test
A test plan documents the strategy that will be used to verify and ensure that a product or system meets its design specifications and other requirements. Normally the test plan is designed by clients but our test engineer will verify it. Here we uploaded the program to the first PCB of pilot run and tested it with test jig.
Step 5 Completing the pilot run
Now the rest of pilot run is good to go!