![]() Increasing the pressure on the worktool to allow penetration by setting the cutdepth slighly deeper resulted is reliable cutting of the kapton tape but also milled the copper at some places, effectivly isolating the pad from the trace. The capton tape was sometimes not cut as the stiffness of the machine was insufficiant. ![]() The problem that arose and finally let to termination of this stream of inquiry was that the mill head is not very good a plunging. Assembly of BGA and CSP follows a typical surface mount technology (SMT) process: print solder paste, place components, reflow, and inspection. C for 90 to 110 sec For Sn/Pb paste ramp to 150. ![]() 5 After welding, lift the hot air nozzle up and remove the surface assembly board. during reflow (Profile with Thermocouple underneath the BGA) For Pb free paste, ramp to 180. 4 Turn on the heating power, adjust the amount of hot air, and start reflow welding of the BGA device. CSP behaves in a similar way to BGA, except for the fact that CSP is more sensitive to mis-handling. 3 Fasten the hot air nozzle on the BGA device, and be sure uniform distance around the device. The mill is zeroed on the bare copper and the prgram run with 0 z-depth. The downside of BGA is the difficulty in inspecting the interior solder joints. To genereate pngs that contain the soldermask, all that was needed was to adapt the eagle makefile to export this layer to a png. The idea was to first mill out the traces, then with the board still in place, applie a piece of capton tape and mill a second program that would clear the pads of the capton tape. It would be very nice to be able to fabricate pcbs with some kind of soldermask using the fab process. Most PCB layout programs create a soldermask for you. Moreover Nvidia BGAs dont handle even smallest overheat, they will pop. Other will be irreversibly dead (lifted pads, popped PCB) if you will succeed to remove IC at all. You will get 1 working board out of 4 at best. Soldermask is a thin layer of epoxi-resin that is applied ontop of the copper, covering and isolating all traces that do not need to be exposed. No way you can reflow big BGAs with this equipment with acceptable rate of success. We constantly believe that ones character decides products high quality, the details decides products high-quality ,together with the REALISTIC,EFFICIENT AND INNOVATIVE crew spirit for Bga Reflow, Surface Mount Pcb Unloader, Intelligent Pick And Place, Solder Printer,Bga. The fab-process made pcbs lack the soldermask. Bga Reflow Bga Reflow - Factory, Suppliers, Manufacturers from China. I assuemed this was beacause of the escape routes. When processing assemblies with BGAs fitted it is important to apply enough heat to melt/reflow the balls of the BGA to ensure a good solder joint. My first tries did not yield good results, because the solderballs would bridge the pads. While it is important not to apply too much heat during reflow it is equally important for the reflow profile to be hot enough.
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