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vapour phase reflow soldering technology

Yngwie

#18752

vapour phase reflow soldering technology | 30 January, 2002

Can someone pls help to explain what is the vapour phase reflow soldering technology ?

Thx, nifhail

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JAX

#18760

vapour phase reflow soldering technology | 30 January, 2002

nifhail, In a nutshell: Vapor-phase reflow is a process that uses a fluid with a selected boiling point. As condensation of the hot vapor occurs on a cool assembly the assembly's temperature is rapidly raised to match the temperature of the vapor.

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#18765

vapour phase reflow soldering technology | 30 January, 2002

Expanding on a previous poster's comments ...

Vapor Phase Soldering. A solder reflow technology that uses a heated solvent to melt the solder.

Buried deep in the recesses of the SMTnet Library is �Terms & Definitions�.

We started using vapor phase in the late 1970s in our initial forays into SMT. We were soldering BIG RF power transistors to boards with built-in heat sinks. Vapor phase really does a nice job with thick, poorly heat sinked boards and BIG honkin� components. It just got too expensive to run, what with all the environmentalist fervor about perfluorocarbons (PFC). Damn whiners!!!

Now, vapor phase is seeing a glimmer of attractiveness, owing to: * Improved medium from suppliers [ie, 3M, Dupont, Ausimont, F2] * Problems soldering no-leads that are now bubbling to the surface, because vapor phase reflow can reflow solder at a relatively lower temperature.

Search the fine SMTnet Archives for supplier contacts. Standard search rule apply: you say to-MAH-to, I say to-MAY-to.

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Yngwie

#18779

vapour phase reflow soldering technology | 1 February, 2002

This can be a solution for IC/BGA soldering for lead-free process isn't it ? See, most of the reflow profile set meets solder paste specification but often violating ICs or BGA requirement. Most of the solder paste required temperature of about 205 - 225 Deg C for the peak temperature. But if my profile went up to 225 Deg C at the solder joints, the IC's body temperature normally will be 4-5 deg higher, where component's specs. calls for max reflow peak at only 220 Deg C. Fine, we can always set lower peak to meet this 220 Deg C requirement. But how do we go about with lead free soldering say Sn/Ag/Cu where meltin point is 217 - 219 DegC. Can vapour phase soldering helps component's leadfree soldering readiness?

cheers.... nifhail

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#18782

vapour phase reflow soldering technology | 1 February, 2002

Yes, that's what people are thinking. The 217�C melting temperature that you mention requires a ~250�C reflow temperature. Generally, boards, legend ink, and components cannot take that temperature. Further, few ovens can produce that temperature with the process control, required in many plants.

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