Electronics Forum | Wed Aug 09 10:51:22 EDT 2017 | cbeneat
I have a question for the experts. After a panel is printed, how long is too long for the panel to sit prior to reflow? I understand each paste will be different, wondering if there is a general rule of thumb?
Electronics Forum | Wed Aug 09 12:34:54 EDT 2017 | jdengler
It also varies with the types of deposits. Small deposits of paste (as seen on fine pitch parts or small chips) seem to be more affected by exposure. Jerry
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 | Tue Jan 09 22:04:48 EST 2007 | Guest
Set Up Guy, I am not sure if the COB you are refering to means Circuit on Board . If yes, this process also include SMT . Package is a combination of some passive components and bare die. Passives are normally attached thru SMT using solder te
Electronics Forum | Tue Oct 04 11:54:49 EDT 2011 | davef
We'd like to help you, but we don't have a clue of what you're talking about. * Which 'heatseal' machine are you using? Is that a reflow soldering machine? See, we think of a heatsealing machine as one that bond the two sides of a plastic bag togethe
Electronics Forum | Mon Jan 29 12:09:55 EST 2018 | fluxgate
I am working on a magnetic sensors design and noticed that my measured magnetic field bias shifts over time. I have studied the bare PCB and measured that it can be magnetized with a strong magnet. I tested two blank (unpopulated PCBS). The first PC
Electronics Forum | Mon Oct 25 03:43:26 EDT 1999 | Joe
Hello, Acceptance Quality Levels vary from company to company and product to product. I would like to know what AQL's are being used in the different markets, (military, telecommunucations etc.). What is the standard level used? What
Electronics Forum | Thu Aug 21 09:01:46 EDT 2003 | caldon
Dan- We here do double sided reflow: we place one side and reflow....place the other side and reflow. On the second flow the underside of the PCB- we will reduce the bottom side preheat. fortunatly for us the largest component we only place a 40pin P
Electronics Forum | Thu Mar 15 09:11:06 EDT 2007 | jdengler
Chrissie, This varies widely by paste, room temperature, and humidity. You would need to do a DOE for you exact set-up. Since you say the room is uncontrolled you need to keep in mind that time will drop as temperature goes up. Different pastes re
