3 ms·
The PCBs in cell phones are almost exclusively done by machines. You can't hand solder a BGA, a machine applies solder paste as the last step in the PCB manufa
by mbell 15y ago
The PCBs in cell phones are almost exclusively done by machines. You can't hand solder a BGA, a machine applies solder paste as the last step in the PCB manufacturing process and then a pick and place (robotic arm pulling parts off reels) sets the chips before sending the PCB through a reflow machine (an oven).
Even for small batch runs of boards with QFP chips (which you can hand solder) you would machine all this, and I mean like 50 board runs. I've even done this in lab for 10 board proto runs. You make a solder paste stencil out of plastic to apply the paste after you get the boards back from the PCB manufacturer, place the chips and solder them in a reflow oven (or even a frying pan works if you paying attention and have an IR temp sensor).
The only bits you hand solder, even in Asian, are components that are too large or can't withstand the temperatures of machine soldering, be it wave or reflow (think full size RCA connectors on a board with many fine pitch ICs or a wall wart). This is normally a post processing step after everything else has been reflowed. Connectors of this type don't really exist in cell phones, they are all surface mount with some minimal unsoldered through hole supports.
The manual assembly that comes into play with a modern cell phone involves connecting the various PCBs with their interconnects and placing them in the proper location within the packaging and of course all the post electronics stuff.
- Retric 15y agoI agree with what you said. By putting boards together I meant something much closer to this: http://www.youtube.com/watch?v=VTQXGLDXQk8 http://www.youtube.com/watch?v=VTQXGLDXQk8 vs. http://www.ethiotube.net/video/18959/Cell-Phone-Assembly-Plant-In-Bahir-Dar-Ethiopia http://www.ethiotube.net/video/18959/Cell-Phone-Assembly-Pla... where you can see several people using a soldering irons about 2 min 10 seconds into the video. But, it looks like the iPhone uses screws where a lot of companies used blobs of sodder to secure things. http://www.youtube.com/watch?v=5U6HjbGCtqE http://www.youtube.com/watch?v=5U6HjbGCtqE Which I suspect increases their labor costs to reduce the number of assembly errors and allow them to be repaired. Of course if they did this in the US, the cost benefit equation changes and I suspect they would do more soldering because it's so fast. PS: The point I was trying to make with Intel is once your 99.9% automated vs say 98% the laber costs stop being the major concern. Which is why Intel still builds chip factory's in the US. It's great to be close to your suppliers, but it's also valuable to be closer to your engineering team.
- mbell 15y agoBoth videos are about very different classes of devices from a "modern cell phone". For example you can't blob solder on a data link to a 960 × 640 full color LCD, you'd lose signal integrity. Intel builds their factories in the US because they are required to by law (export controls on certain high tech). I think they are allowed to build some lower tech stuff outside the US (Israel for instance).