![]() Clearly, if two different PCB assemblies are very similar and have the same process window, then it will be possible to select a single recipe that will produce an acceptable profile for both assemblies. (It takes longer to cool down an oven than to heat it up.) The key to instant or fast oven changeover is intelligent selection of the oven recipe. It may take an oven 10, 20, 30 or even 40 minutes to stabilize on a new set of temperatures, especially if the new recipe is cooler than the previous. It is imperative that the correct recipe is selected to establish the acceptable profile for all the different PCB assemblies. Each different set of zone temperatures and conveyor speed will produce a unique profile on a given assembly. We can even think of the reflow oven as a profile-producing machine.Ī reflow oven has literally billions of alternative recipes. In other words, the oven needs to produce the correct profile. temperature profile of the solder joints, PCB and, most importantly, the components. The way we measure and control this is by the time vs. So the reflow oven needs to solder the assembly within the tolerances/process window set by the relevant solder paste, components and substrate. ![]() ![]() #OVEN REFLOW CRACKED#Clearly, we do not want a strong solder joint that cracked the component in order to achieve it. All of that is true but there is more to it. I always ask process engineers the following question: What is the main job performed by the reflow oven? The answers tend to be to melt solder, solder the components onto the board and create a strong solder joint. The goal should be instant oven changeover, and that goal is achievable in the majority of applications.įirst, a few observations of the purpose of a reflow oven. Having a $2 million production line sitting for 30 minutes+ while waiting for a $40,000+ oven to stabilize on a new recipe will wreak havoc on profits. One obstacle tends to be the reflow oven. Improved technologies for line balancing, production planning, smart feeders, MES and more are being used more effectively to allow for faster production line changeover and less downtime. ![]() Instant Reflow Oven Changeover in a World of Short Production RunsĪ clear industry trend now spreading beyond the traditional North American and European markets is characterized by short production runs and frequent production line changeover. ![]()
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