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Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Wave Solder Dwell Time

Greg G

#2548

Wave Solder Dwell Time | 4 November, 2000

Hi Guys, I'm sorry to ask you this, but I got mixed infos from the archive. I want to define a process in wave soldering regarding bd-wave interaction. Now "What's the required dwell Time of a lead in the solder bath?" Some says 3-5 secs is good, some says 2-3 secs, some says 1 to 1.5 is good, some says the shortest the best but it should have no defect.

thanks, greg g.

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Aoki Laboratories Ltd.

#2549

Re: Wave Solder Dwell Time | 4 November, 2000

Greg, The operating parameters for Wave Soldering are: 1. Preheat Temp. (80-110 c, board surface); 2. 1.5-3 secs dwell time in solder. This, 1.5 second, is the time required for both the lead and solder to gain sufficient heat and as a result "tinned", in the wave soldering process. If some leads have incorporated nickel, copper or iron in them, then I suppose longer dwell time may require.

David L

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#2550

Re: Wave Solder Dwell Time | 6 November, 2000

That's cool that you used the Archive.

Consider running a designed experiment on your board, using your flux and solder, the limits from the Archive, and on your machine to dial in the spread in dwell numbers you see in the SMTnet Archives to your specific needs. Dwell, as you likely know, is critical to getting good wave solder connections.

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CharTrain

#2551

Re: Wave Solder Dwell Time | 7 November, 2000

A solder wetting balance will indicate a time of less than one second for wetting to occur to a solderable surface. The additional time is required to get the metalized surfaces up to soldering temperature. A single sided board has very little mass and will acheive the required temperatures very quickly (1-1/2 secs)A larger multilayer assembly with ground planes and large components will require more time - how much is determined by profiling the assembly. Part of the heat comes from the preheaters as explained in an earlier posting but the balance comes from contact with the molten solder. Preheaters take you up to 100C but solder melts at 183 so the contact with the wave is where the balance of energy comes from. Then comes the fun such as seeing if the flux you have chosen can hang in there long enough to get the job done (they all don't) Ray

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Steve Geldard

#2552

Re: Wave Solder Dwell Time | 7 November, 2000

Hi Guys,

Ive seen your notes on Wave dwell times, we have been doing lots of test across many styles of wave machines. The most inportant thing to understand is that your dwell time does vary across the wave, it can vary as much as 2 to 5 secs from left to right and also you can have voids in certain areas. There is equipment available today to measure this digitally. We have found 2 to 3 secs on the main wave & 0.5 to 1 on chip waves is typical. It realy does depend on the type of board you are making. Good luck. Steve Geldard

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reflow oven profiler