That is why you don't see a lot of small vapor phase systems, even thought it has the advantage. So you have a high equipment cost, initially, and a high operating cost because of the expensive fluids. I've heard numbers above $1,500.00 a gallon.Įven with the best systems you're always losing a little, particularly in a prototyping system where you can't optimize your cycles and so forth. Typically $500.00 to $700.00 a gallon for tin lead fluids and for the lead-free fluids, which you have to boil at 235 or 240 there's only one supplier in the world. You've got to have a filtration system which adds a lot of money to the base cost, even for a relatively simple system to do small prototypes.Īlso the fluid is very expensive. You have to have a stainless steel high temperature tank, high temperature heaters, cooling coils with an active water circulating loop, either once in or recirculating. With vapor phase even for a simplest system you have to have a lot of expensive hardware. Why don't you find much vapor phase equipment? Quite simply because the equipment is expensive and the fluids are expensive. So vapor phase is definitely better and safer and easier to get a good reflow first time, every time. If you go the other way, and to ensure good soldering you have to use longer cycles or slower conveyor speeds and/or higher heater temperatures, in which case you take the risk because you haven't had an opportunity to profile the board of overheating and damaging something that may, as we say, be a one-up in a prototype environment. If it's underneath a BGA or another area array that could be a real problem in a prototype. In that case you may not get good reflow on all your joints. So you've got to set up a recipe in your oven and you either have to be conservative and use a short cycle, or fast conveyor speed, and low heater temperatures to minimize the risk of overheating something and damaging it. We hope that you are talking about modern convection-dominant systems that have powerful fans that transfer most of their heat by convention and give you a much better temperature uniformity and allow you to keep the temperatures lower and minimize the chance of overheating.īut still, with the prototype you may only get one shot. Whereas with convention-based, first off we want to talk exception to the term "IR Convection." To us that means the old Vitronics panel IR-based systems, which are definitely inferior in the heating characteristics and are even worse for prototyping. Vapor phase allows you to take any assembly, put it into the vapor phase system and completely reflow all of the joints without any risk of overheating anything and damaging it because of the inherent temperature control of the vapor phase process: 215 degrees for tin lead, 235 degrees for lead-free assembly. Think about prototyping: you have maybe only one set of parts, you want to get a functional board to get it operational and you don't want to damage anything. Yes, from a process standpoint vapor phase is superior to convection-based systems. Okay, so this is a vapor phase question, which means time for our vapor phase expert: Jim Hall, front and center. That should normally mean that the supposed process control and environmental advantages, the vapor phase process has some important disadvantages about which the cognoscenti such as yourselves (flattery will get you everywhere) could expound. There are many suppliers for batch ovens and it's hard to find spares of vapor phase equipment. from somewhere: "Could you please compare the advantages of IR convection reflow and modern vapor phase reflow with polymer solvents for small-scale prototyping environments. We're here to discuss process problems, situations and possible solutions to all your electronic assembly needs, or at least the ones we think we're qualified to answer, or even some we're not qualified to answer. This is Jim Hall and Phil Zarrow, the Assembly Brothers who sometimes go as ITM Consulting. He is a pioneer in the science of reflow. He has vast experience in SMT equipment, materials and processes.Ī Lean Six-Sigma Master Blackbelt, Jim has a wealth of knowledge in soldering, thermal technology, equipment and process basics. With over 35 years experience in PCB assembly, Phil is one of the leading experts in SMT process failure analysis. Process Troubleshooting, Failure Analysis, Process Audits, Process Set-upĬEM Selection/Qualification, SMT Training/Seminars, Legal Disputes To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video.Ĭompare the advantages of IR convection reflow and modern vapor phase reflow with polymer solvents for small-scale prototyping environments.īoard Talk Board Talk is presented by Phil Zarrow and Jim Hall of ITM Consulting.
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