Electronics Forum | Sat Mar 04 13:26:41 EST 2006 | jldowsey
Something unusual happened yesterday, we reflow soldered two boards with white silkscreen legend, and they came out of the oven with purple silkscreen legend. Not tan or brown from overheating, but purple. The boards were reflowed on their normal pr
Electronics Forum | Fri Mar 10 19:22:32 EST 2006 | bman
I hate to ask an obvious question, but are you sure all of your thermocouples are attached properly? I just can't imagine a 3X5 board having such a large Delta T unless it has some really odd parts on it. You sound like you know what you're doing,
Electronics Forum | Wed Mar 15 21:34:07 EST 2006 | Chunks In Cebu
I can see why he left. Not knowing your board or paste, but I would tend to say your profile is on the cool side. Unless your boards are very small and your conveyor speed is slow, I'd say this is no good. It looks like you're using the old "ramp,
Electronics Forum | Wed Mar 15 09:28:30 EST 2006 | mapell
Vick I would not think what your seeing is normal. Just guessing without a profile but.... - not reaching peak temperature - not enough soak time or mild ramp to burn away the flux - shortened TAL, not allowing proper time for the solder to wet - lo
Electronics Forum | Thu Mar 16 10:15:55 EST 2006 | slthomas
I would again suggest that you REALLY need to profile that board. It does sound like you're not getting enough heat to that component, but if you just crank up your reflow zone how will you know you're not overheating something smaller unless you b
Electronics Forum | Thu Mar 16 12:48:12 EST 2006 | russ
The copper based part is it copper that you are soldering to or did you tell us what the base material was for the lead. Generally all leads are plated with something such as Tin/Lead, palladium over nickel, tin, etc... You cannot solder to bare co
Electronics Forum | Fri Mar 17 07:42:51 EST 2006 | vicknesh28
Copper is the base material for the lead. It's tin/lead plated. I finally got profile. Here are the parameters" Peak : 219 Max (+) Slope : 2.29 Max (-) Slope : -1.94 Time above 200 deg. C : 50s Time 140C - 160C : 126s Additional info : Stencil thic
Electronics Forum | Tue Mar 28 15:11:56 EST 2006 | GS
Hi MLC, did you profiled the BGA itself? I mean detect Temperatures on middle/central ball vs external ball and see how much is the delta Temperature. Best practice is to keep the delta T at minimum as possible especially on a so large BGA. Sure
Electronics Forum | Sat Mar 25 16:05:13 EST 2006 | loz
Hi, sounds unusual if your profile is accurate that you have so many residues. Had a similar problem before with no clean flux and with various flux manufacturers, and all residues were down to excess flux. This does not help your case though. How a
Electronics Forum | Thu Apr 27 11:50:21 EDT 2006 | samir
90% of the battle with thermal profiling is your thermocouple attachment. That is Process Engineering 101. It's just like painting your house. The masking and prep work will make or break the end result. KIC did a DoE on which thermocouple attach
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