Electronics Forum | Mon Apr 02 10:46:03 EDT 2007 | slthomas
Hand up here too. While most pastes have some flexibility and you may get by without too many problems, I don't think any of them are designed with long wait times in mind. What I'm confused about is what your operator is doing when boards ARE runni
Electronics Forum | Tue Apr 03 13:10:15 EDT 2007 | slthomas
Personally I wouldn't count anything but minutes. You need to know how long it takes to perform each task in order to balance your line. What I'm gathering is that you've got one printer feeding 4 machines, all running different jobs or maybe a pai
Electronics Forum | Mon Apr 02 09:57:19 EDT 2007 | ed_faranda
Yes, Hand Up here. I would think you would have a quality problem. I am assuming you're doing this process in some sort of batch mode. I would hope that you can process your boards within a few minutes after components being placed. Things that I
Electronics Forum | Wed Apr 04 03:38:04 EDT 2007 | chrissieneale
The two machines in the middle are really really old m/c's so we try as much as possible to not to use them (apart from as very expensive conveyor belts). They run a fixed set up as although we have a bunch of different products they all tend to use
Electronics Forum | Wed Aug 09 11:59:19 EDT 2017 | dleeper
As you already know, it depends on the paste. There isn't really a rule of thumb, but less time exposed it better. The issue is the flux exposure to the air and ambient conditions. The flux can evaporate or absorb moisture from the air. If the paste
Electronics Forum | Thu Aug 10 11:32:34 EDT 2017 | dleeper
You could always take a scrap board, paste it, and let it sit out over night. Reflow it and then you should have a nice visual aid, covered in solder balls and grainy, irregularly shaped solder mounds.
Electronics Forum | Tue Aug 15 07:27:03 EDT 2017 | emeto
Most important factor - temperature. Back in the days I worked for a place without AC, and summer time this paste couldn't make it for more than an hour. In controlled environment you will be safe for hours or even a shift.
Electronics Forum | Fri Nov 09 11:55:49 EST 2001 | mparker
If you are getting solder shorts under a device, how would "hiding" the extra long pad with solder mask help? If the pad can't be seen once the device is in place, it is already "hidden". Getting your customer to redesign the pads may take some time
Electronics Forum | Mon Oct 25 15:45:11 EDT 1999 | Dave F
Joe: Lemme see, you�re talking about controlling your manufacturing process within 4.6 defects per 100 opportunities or a 4,600 dpmo rate, a cumulative 99.95 acceptance rate, or a �2 sigma process, right? So, it�s fairly basic stuff, eh? First, yo
Electronics Forum | Thu Jul 20 23:41:55 EDT 2017 | heros_electronics
Below is an email that I copy and pasted from my customer's engineer about his concerns with the issue of the chips not reflowing (which is why I was asking about X-ray the chips to make sure they reflowed): Can you let me know your thoughts on his
