Electronics Forum | Wed Oct 17 02:53:36 EDT 2001 | dszeto
The fine pitch QFP is a 240 pin one being loaded with other components on a 2.0mm thick FR4 PCB. There are 6 of this Qfp's on this PCB showing the same charactristic of bowing therfore the solder fillets are vary from the center to the end of the pa
Electronics Forum | Tue Dec 11 20:15:36 EST 2001 | mparker
What happened to good ol' 30 ga. hook up wire? I used to be a whiz with a wire wrap gun. I've even hand soldered wires to a 240 pin QFP (the Engineer was too cheap to buy a $80 socket). Just what are they teaching in these edifices of matriculation
Electronics Forum | Fri Feb 01 15:09:43 EST 2008 | chef
Don't do it.!!!! Are you nucking futs? Why is pre-bake required? Are you producing in high humidity? Is the package of the device poroues enough to suck in moisture? Think, consider you will not get an even "bake", the outside of the reel will get
Electronics Forum | Tue Jun 02 16:02:13 EDT 1998 | Earl Moon
| First of all let me say that we are currently placing other 240 pin QFP'S with no problem. But none of them have the MASS of this beast. | The part is a XILINX XC5215-6HQ240C which has a large metal heat sink covering most of the bottom of the part
Electronics Forum | Mon Jun 01 17:41:59 EDT 1998 | Jim Hoxie
First of all let me say that we are currently placing other 240 pin QFP'S with no problem. But none of them have the MASS of this beast. The part is a XILINX XC5215-6HQ240C which has a large metal heat sink covering most of the bottom of the part. T
Electronics Forum | Tue Jun 02 08:30:30 EDT 1998 | Jon Medernach
I have to agree with Steve. If the problem is progessively worse the problem is the pitch conversion that was used, and I have seen it before. It may be masked by the solder paste which could be on pitch but after reflow the paste wickes to the pad
Electronics Forum | Sun Jun 06 08:00:06 EDT 1999 | Dave F
snip | Ryan, | | The only advive I got is just don't do it!. Dave's right the grain growth in it is pretty bad. the other thing you got to look at is how much heat is the board gonna produce in it's working life..??? and where is it gonna be used,
Electronics Forum | Fri Nov 30 17:33:12 EST 2001 | slthomas
After saying for years that we'd never do two-sided assembly, the powers that be are not only saying we will, but they're threatening to throw an out of house design at us...no frame (it's a PCI card with a couple of dinky breakaway tabs), no tooling
Electronics Forum | Mon Jun 30 09:43:03 EDT 2003 | russ
Try searching the archives, I saw the formula posted in an earlier thread I belive that relating to Double sided with BGAs but I am not sure I think Dave F. posted this one. So what is an "R"QFP I haven't heard of that one before. Russ
Electronics Forum | Thu Jun 03 14:40:22 EDT 1999 | JohnW
| | | | In a month or so, we will be getting an in-line x-ray inspection machine. It will require that we solder our most comlicated side (normally top) first. This is opposite to our process now where we solder our passive (bottom) side first. W
