Vapour Phase Reflow Profiling (Would like to understand more on how to determine a PCB's Profile/Recipe)

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Hi All, Appreciate any inputs that may be given. Currently ... - Jun 27, 2022 by Kelvin C

I have never used a VP oven, but I did get a pretty good dem... - Jun 27, 2022 by ProcEng1

Hi Sir, The VP Machine that i am currently using takes refe... - Jun 27, 2022 by Kelvin C

Very interested what kind of profiler you use to check your ... - Jun 30, 2022 by Evtimov

Kelvin C

#88139

Vapour Phase Reflow Profiling (Would like to understand more on how to determine a PCB's Profile/Recipe) | 27 June, 2022

Hi All,

Appreciate any inputs that may be given. Currently i am operating VP6000 Vapour Phase Reflow Oven from ASSCON.

Over the last 2 years, we have around 100 different Recipes for many different PCBs. Each recipe is adjusted(6 Different Parameter Settings on the Reflow Oven) specially for each PCB.

As of now we are trying to create a software that uses the past settings of each Recipe and cross comparing the new PCB we have according to the Past PCB(Which already has a recipe for itself) to recommend us the best suited settings to use.

The Cross Comparing Parameters will be: 1. PCB Length, Thickness and Width 2. Layer Counts of PCB 3. Copper plane ounce and volume 4. Bare PCB's Weight and PCB with Components mounted weight

As this has got to do with Thermal transfer, i would like to ask the community if there is any other parameter which i should take into account when cross comparing the new PCB with another PCB(of different design but similar in parameters) which has been assembled before.

The aim of the software is to match my New PCB with one PCB that has been assembled before and return me the Parameter Settings for that matched PCB

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ProcEng1

#88140

Vapour Phase Reflow Profiling (Would like to understand more on how to determine a PCB's Profile/Recipe) | 27 June, 2022

I have never used a VP oven, but I did get a pretty good demo of one and was pushing hard for my company to acquire one. The issue ended up being that there was not an East Coast distributor for the "juice" and that became cost prohibitive to get shipped from West Coast.

That said, I thought that profiling and repeatability were the two biggest attributes in the "plus" column? In conventional reflow ovens, you basically set the zones to WAAAY above the actual temp you want. My last zone might be 280 just to hit a board temp of 235. And it's quite possible that a recipe developed today, might not work as well in 6 months when that job comes around again. Maybe a heating element was replaced and now heats up a bit more efficiently, or maybe the TC isn't reading as accurately as it once was or whatever.

The VP that I was shown had temp sensors are on the board at all times and it moves the board into the vapor in order to reach the desired temperature at each "stage". And if in 6 months it needs to drop the platter an extra 3/4" inch just to each the same temp, it would and you'd never know. As we were shown, you could basically input the points of the graph on the solder data sheet and it would just make those temperatures happen at those time points.

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Kelvin C

#88141

Vapour Phase Reflow Profiling (Would like to understand more on how to determine a PCB's Profile/Recipe) | 27 June, 2022

Hi Sir,

The VP Machine that i am currently using takes reference from its own temperature sensor. so most of the time i would have to adjust multiple times for my PCB to soak at the right temperature or reflow for the duration that i need it to.

For example, when i adjust the Start Soak Temperature at 150 degrees, the sensor of the machine may reach it at time: 5mins 30 seconds however my pcb might only be at 130 degrees at that point of time.

Thus i may have to adjust the temperature to be at 170 degrees in order for my PCB to reach 150 degrees.

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Evtimov

#88154

Vapour Phase Reflow Profiling (Would like to understand more on how to determine a PCB's Profile/Recipe) | 30 June, 2022

Very interested what kind of profiler you use to check your profiles? KIC and Datapaqs have some predictors when it comes to reflow ovens or wave machines.

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