The Assembly Line

You don't just walk into the assembly line. You are made to wear certain clean-suits. These are not as stringent as the PPE suits worn in semiconductor foundry clean-rooms; but still you end up better dressed than a surgeon at a hospital. Once you've donned the clean suit, which includes grounded-footwear, headmasks, (and face masks if you intend to get too close to the machinery); you are tested for your ESD potential. Once that's cleared, you enter a special chamber where a blast of air decontaminates most particulate matter off your surface.


You then enter an otherworldly place to the sound of machinery intricately placing components on PCBs. The air-quality is easily on-par with that of an ICU.


The PCB is the foundation of the graphics card. It's the main real-estate where the various components are wired to each other, to make the device work. PCBs arrive in vats filled with anti-ESD packaging that have in-situ chemical strips to tell you how much moisture or other elements that the PCB has been exposed to. Right next to the vats with the PCB, are vats filled with trays of the actual GPU ASICs. A GPU is a large component with exposed dies, and cannot be shipped in reels, so it arrives in trays instead. Each of those silver foils contains anywhere between 20 to 60 GPUs, depending on the size of the GPU package. This is AMD's scope of delivery to its board partners, besides reference PCB designs, reference BIOS, and QVLs for compatible components.


The first machine on the assembly line is fed PCBs and solder paste, which it applies precisely to all the soldering points of the PCB. It does this using a stencil that corresponds with all the soldering points of the PCB. A large dispenser arm pours solder paste over the stencil, which ensures it's applied on precise locations. After this stage, a laser-optic scanner inspects the PCB to see if the solder is correctly applied (in the right measure), and shares its findings with the previous machine, so it can correct flaws for subsequent PCBs. A PCB with major flaws in solder application is ejected, so it can be manually cleaned up and re-processed by the previous machine.


We now move onto our favorite machines in the entire factory, the PNP (pick and place). This is possibly also the most expensive machine. After application of the solder paste, PCBs that pass inspection are vestibulated to the PNP machines.


Each of these machines has two armatures that move along three axes, picking up components from reels, and placing them where they need to be on the PCB. The smallest SMDs are placed first, and then moderately sized ones (such as larger capacitors, inductors, connectors, etc., and finally the largest components that are fed to the machine in trays (such as the GPU ASIC). When at work, a PNP machine's armature sort of sounds like an inkjet printer.


After the PCB goes to several PNP machines dealing with the various components, it goes through the convection reflow oven, where specific regions of the PCB are subjected to specific temperatures that cause the solder to melt and cool, and for the component to solder onto the PCB. As you've probably guessed by now, a graphics card PCB has SMDs on both its obverse and reverse sides, and so the PNP process is repeated for both sides before being sent to the oven.


The component PNP process is where statistically, the highest number of manufacturing defects are prone to occur, and so PowerColor invests in stringent quality control for this stage. An X-ray scanner inspects a PCB to check whether all components are soldered correctly, particularly those components such as the ASIC and DRAM chips (components with BGAs), that cannot be visually inspected for defects. X-ray also allows line engineers to inspect vias and connections within the various PCB layers. After this, the PCB goes through additional stages of manual inspection.