Vapour Phase Soldering

I would appreciate hearing views on vapour phase soldering particularly in respect to BGA's. I know that they used to use CFC's but apparently this is no longer the case? Can anyone help with some info? Thanks, Alan Brewin

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| I would appreciate hearing views on vapour phase soldering particularly in respect to BGA's. | I know that they used to use CFC's but apparently this is no longer the case? | Can anyone help with some info? | Thanks, Alan Brewin Alan, Unfortunately, this process is virtually extinct in the US. With the advent of forced air ovens whose thermal transfer efficiencies are great, the cost to produce a vapor phase reflowed joint became prohibitive. There are few, if any, capital equipment manufacturers still cranking out vapor phase gear. Although the thermal transfer is great within the vapor phase environment, I for one always shied away from the thermal excursion required to go from ambient room temp to vapor temp. Many folks performed a preheat operation prior to reflow. The fluid is expensive, and equipment maintenance intensive. I would strongly recommend that you go with forced air convective process. Scott Cook scottc@t-com.com

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Thanks to Scott for your reply, much appreciated. Are you aware of any new developments in this area? Particularly in respect to the solvents? We are aware that fluorine chemistry is now in-use with amazingly high boiling points. We understand that using forced air convection cannot guarantee adequate profiling thru the entire underside and you will get uneven solder joints. This cannot be disputed at least because of the thermal transfer at each solder point as the air attemts to get under the BGA. We also understand that the use of IR is not good because of the thermal shock thru the entire component. Vapour phase could therefore be a great new/old idea? Onwards thru the fog.... Alan Brewin | | | I would appreciate hearing views on vapour phase soldering particularly in respect to BGA's. | | I know that they used to use CFC's but apparently this is no longer the case? | | Can anyone help with some info? | | Thanks, Alan Brewin | Alan, | Unfortunately, this process is virtually extinct in the US. With the advent of forced air ovens whose thermal transfer efficiencies are great, the cost to produce a vapor phase reflowed joint became prohibitive. There are few, if any, capital equipment manufacturers still cranking out vapor phase gear. | Although the thermal transfer is great within the vapor phase environment, I for one always shied away from the thermal excursion required to go from ambient room temp to vapor temp. Many folks performed a preheat operation prior to reflow. | The fluid is expensive, and equipment maintenance intensive. | I would strongly recommend that you go with forced air convective process. | Scott Cook | scottc@t-com.com

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:> No problem..... > No; the last time I used the process was 1983. > Yes, and in your neck of the world, I'd bet you're looking at Flutec products.....(I used PP11 juice way back in 1979). > I would dispute this. I did EXTENSIVE testing for thermal efficiency before purchasing my last oven in August of this year. Without getting into the actual testing procedure, Today's IR / Forced Air / Convection ovens are very good at efficiency of thermal transfer. > I totally disagree. With a proper thermal profile, the IR / Convection process shocks components LESS than going from ambient room temp to the vapour (british spelling intentional) phase vapor temps...... > Again, I ask: Where do you find current vapour phase capital equipment? How much of it is in the field? Where's the industry expertise level? What support with equipment and process will you receive? > just my opinions..... Scott Cook

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VP does work well for BGA Technology but it is not any great improvement on convection reflow. It has been stated in a coulpe of articles that there is no delta T difference with VP from the surface ofthe board and under the BGA. That is not true just like convection there is a difference. There are very few VP units being used compared to convection systems but they do have a place in the industry. | I would appreciate hearing views on vapour phase soldering particularly in respect to BGA's. | I know that they used to use CFC's but apparently this is no longer the case? | Can anyone help with some info? | Thanks, Alan Brewin

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I have been using Vapor Phase for about 5 years. We just started building our first BGA and the reflow profile is the same as most SMT assembly.We build PWA that are 25 layers thick with 0.050 heat sinks. We have done some preliminary X ray and BGA solderjoints look good we are in the process of getting micosectioning accomplished. This is an old technology that makes BGA EASY WORK just like regular SMT. 813-539-3683

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