Electronics Forum | Wed Jun 22 14:14:42 EDT 2005 | Steve
Tin/Lead we have had no problem in masking off areas on a pcb during wave soldering. Lead Free alloys, Nickel Silver Copper would there be any compatability issues with a Peelable latex solder mask containing Ammonia. Really hot need to know.
Electronics Forum | Wed Jun 22 15:03:12 EDT 2005 | patrickbruneel
The only thing ammonia can do is tarnish copper and make it more difficult to solder. And the higher temp in lead-free will discolor the latex (giving it a sticky surface), but the functionality of the mask will be intact. There should be greater co
Electronics Forum | Thu Jun 23 07:09:54 EDT 2005 | geb
Does anyone know why my MPM AP-27 machine would forget its fiducials? I make the program, save it, and then when I run the program it says it doesn't recognise the board even though I just taught it! Has anyone else had this type of problem or have a
Electronics Forum | Thu Jun 23 13:43:29 EDT 2005 | Stefan
I fear your files are not stored in the default directory or your hard drive is full. Boot with a DOS boot disc and check your C drive for program and fiducial information. Try an older program to check if the program structure and vision informatio
Electronics Forum | Thu Jun 23 16:09:51 EDT 2005 | pr
Oh Yeah, I've had an AP27 I would say it just doesn't like your fid. Just click on the window in the bottom left and it'll go full screen (then click main menu to return). Check the easy stuff first, Make sure you have a consistant load (in the cente
Electronics Forum | Thu Jun 23 14:13:52 EDT 2005 | Frank
Luckily I haven't needed to do very many bottom side BGA placements. But I have also heard of trying to use a higher temp solder for bottom side only and your normal solder for the top side. This way the bottom side solder doesn't get hot enough to
Electronics Forum | Thu Jun 23 10:36:04 EDT 2005 | stepheniii
I think the single most important thing will be to maintain positive pressure in the room. All the air filtering will not be able to keep up if dirt is blown into the room everytime a door is opened. The next would be to control as much as possible,
Electronics Forum | Thu Jun 23 10:49:46 EDT 2005 | slthomas
Your HVAC contractor is probably the guy to talk to (they can hook you up with a variety of air handling and filtration systems depending on the level of cleanliness you want). Another thing you can do is reduce the amount of dust you bring in and/
Electronics Forum | Thu Jun 23 12:59:09 EDT 2005 | jdumont
That was a great article. Luckily for us we dont build at the wafer level. Only PCB assembly through surface mount and wave. I like the positive pressure idea. Im going to contact the HVAC guy and see what he thinks. I think that just being in a clos
Electronics Forum | Mon Jun 27 09:38:30 EDT 2005 | Bob R.
What problems are the quality people seeing? I hope they aren't expecting a toe fillet. QFNs are typically cut from an array after plating. This leaves exposed copper on the sides of the part. We'll often see smearing from the sawing process that