Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.

Wave soldering temperature

Tim Almy


Wave soldering temperature | 4 November, 1999

Is 260 degrees C / 500 degrees F the optimum temperature for wave soldering ?

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Re: Wave soldering temperature | 4 November, 1999

Hi Tim It sort of depends on the solder alloy being used and the particular assemblies being soldered. If you are using the usual 63/37 alloy I would consider 500 to be a bit warm unless the assembly required it. Some alloys would require a higher or lower temperature. The main drawback to the higher temperature when not needed is increased dross production. The possibility of component or board damage would also be higher. We run our wave at 470-475 degrees. Any lower and the solder seems to get "sluggish" and bridging increases. You could search the forum archives for more information. John Thorup

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Re: Wave soldering temperature | 4 November, 1999

I'm with John.

Back in the old MIL-2000 days, the pot temperature was 245-275C (475-525F). Now, 240-260C (460-480 F) is more accepted for eutechic (eutechicish) solder.


Dave F

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Re: Wave soldering temperature | 5 November, 1999

Temperature vs time is what soldering is all about. The faster you run your conveyor, the more heat will have to come from the pot for a given assembly. Example: You heat the board to 200F top side through the preheaters. Eutectic 63/37 melts at 361. When the assembly hits the wave it has to absorb a min of 161 degrees of energy to wet to the solderable surfaces. The faster you run the less "dwell" or contact time to transfer the energy. Solution is higher bath temp (500F)Lower pot temps as explained by John are to avert thermal shock on bottomside ceramic components.I've been in contract mfgs who run low pot temps for SMT and then wonder why they don't get flow through on multilayer assemblies. Also as John stated, the lower temperature, the higher the viscosity of the solder which makes it sluggish. Unless you have bottomside ceramics, stick to 500F. Above 525F, DROSS production becomes exponential. Ray Ray

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Re: Wave soldering temperature | 9 November, 1999


I try to get 2-3 degrees C/sec (bottomside) rise on my boards through wavesolder. I like to get the topside to about 90-95 degrees C, but this is the optimum temp for the flux that I am using. To fast of a slope and you will burn your flux off too soon and too little slope will not provide enough heating. The other guys mentioned the solder temp and I don't have any input for you there other than to say I run mine at 240 C.

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