Question on Reflow Profile Development

Greg;

The universal profile concept maybe misleading. the main objective of a reflow system is to reach a certain temperature and maintain it for the required period of time. If your initial profile is set to accomodate this on any board the only variation is the speed at which the product moves through. Most ovens and CCA's require a window to be processed properly. It is possible to achieve a base universal process and then have minor speed adjustments to allow for density and layers. i hope this helps.

Yours truly;

Ken Lester LesCon

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It is possible with a few universal profiles. I did this with 3 temperature ranges and 3 speeds for each, 9 profiles total. With this setup I could run any of about 150 boards most of them in the middle 3 profiles. My goal was to reduce change over it didn�t help a lot with new products because I still had to find the right profile for each board. Well, it did a little they where all about 5 degrees C apart so if I needed to come up 10 in my peek I knew right where to go. This all worked very nicely as far as the change over goes 7 lines into 1 oven and it was almost never a bottle neck.

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The commercial answer is Automole Xpert by ECD.

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One or more of the oven profiler companies [eg, KIC, ECD, Datapaq] has software for estimating profiles. Checkem aut.

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Greg,

You may want to look into having a company that specializes in reflow optimization come to your facility and get you all set-up. Their are many companies that will come in and create the best profiles for your product with a process window that will have some flexibility.

One such company I know of is Pro-Con Technologies, Inc. Check out their site at http://www.procon-inc.com

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I used to associate the mass of the assembly with the reflow profile. The greater the mass, the greater the quantity of heat you need to give the assembly. Most of the time you just need to reduce the speed of travel in the oven. Try different settings with different masses, then put all your data on a chart. Then when a new product come along, put it on a scale to find the mass, look up the chart, pick the profile and voila! Fastest profile setup! This method works great in 100% convection oven.

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Greg: Several year ago we did a lot of work to develop methods for finding reliable common profiles. The process we came up with takes an emmense amount of time, and leaves the user with an "adequate" profile for each product, rather than the "one best profile" for each product. We believe the solution is to minimize profiling and changeover time through the use of software tools. You can look to the sources identified by Dave F above and determine which software will give you the best solution.

Best Regards, Greg Jones KIC

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We use a universal recipe for 90% of our products. But, I had to develop a temperature profile for each PCB to know that I was getting the correct temperature at the PCB.

You may need to work a weekend or a couple of late nights to get the data.

Good luck.

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