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Profiling for Pb-free HASL

Views: 1770

#82521

Profiling for Pb-free HASL | 9 May, 2019

I'm curious about what you guys do for Pb-free HASL profiling.

We seldom see this finish (only on consigned boards or if they specify it directly, which is very rare) so we don't have a lot of experience.

Certainly we get better results with higher peak temps but I don't like to increase my ramp temps very much for fear I'll be out of flux by the time I need it.

Does anyone use a different paste just for this finish?

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#82691

Profiling for Pb-free HASL | 3 June, 2019

We recommend a ramp soak spike profile for HASL finish, so everything gets nicely heated during reflow, we soak around 180C and peak at 245- 250C and don't have any issues as long as the levelling isn't too peaky.

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#82694

Profiling for Pb-free HASL | 3 June, 2019

Thanks! I was beginning to think no one else ever uses this finish, or worse yet, they never profile.

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#82695

Profiling for Pb-free HASL | 3 June, 2019

We see it fairly widely used over in Europe but isnt a particular favourite as if it's not cleaned or prepped properly can be very unreliable.

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#82712

Profiling for Pb-free HASL | 6 June, 2019

Awhile back I faced a few problems because of that. To solve the problem, my only concern was about the peak temperature to assure that the alloy got melted. Peak temperature between 230°C and 235°C can assure that and usually is inside the sodler paste process window. Then I never had a problem again.

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#82713

Profiling for Pb-free HASL | 6 June, 2019

Honestly, If I ever have an SMT problem it's when a profile is at 230-235C. We encourage minimum 240C and typically 245-250C. Many components call for 260C. Some Paste manufacturers advocated 230C in the early years of Lead Free and it was a disaster.

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#82723

Profiling for Pb-free HASL | 7 June, 2019

I totally agree with you when whe talk about a lead-free process.

In my early comment I thought we were talking about a tin-lead process with the pcb pb-free, when the solder paste limits should be respected. That is the motive the temperatures I said before. Now I realize that it is not the case.

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#82859

Profiling for Pb-free HASL | 21 June, 2019

Another question - how would you classify a "pure tin" (supplier term, not mine) alloy with .12% Ni specified? is this a common Pb-free HASL alloy?

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