Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Profiling

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#71559

Profiling | 9 January, 2014

1]How to do a profiling? 2]How the sensors need to connect to the PCB to check & deceide the best profile? 3]What factors ned to be considered during Profiling?

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#71560

Profiling | 9 January, 2014

1. For PCBs we can do thermal profiling

2. Sensor needs to connect to the input pins. the pin no. depends on the sensor quality.

3. Proper input and compatible sensors should be used.

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#71562

Profiling | 9 January, 2014

Thermal profiling typically requires a profiling kit, this will include a thermally insulated datalogger that follows your PCB through the oven connected to a number of thermocouples which you might affix to your PCB using heat resistant tape or using any convenient feature that would hold it in place. You would be looking at measuring the profile at a variety of points on your PCB to check it is being evenly heated and paying particular attention to any areas of interest such as large components. By examining the datasheets of the paste and your components you can built up a picture of the best profile that satisfies each of their requirements as best as possible. This is called the process window index http://en.wikipedia.org/wiki/Process_Window_Index. You will probably find the paste defines a great range of possibilities so it will be your most sensitive device that drives your parameters. There are a few key things you will be looking for: Enough time for the Fluxes to do their work A sufficient peak temperature to correctly reflow all your parts without ever exceeding your devices limits. A cool down rate that does not induce thermal shock. All these key areas will be marked on those datasheets that bother to do so. Others may refer you to the industry standards (which in turn will refer you back to the manfacturer datasheet, nice). Some will argue for a profile to be checked every shift, some every period of time, some for every BOM change or significant alteration of mass and others who have established they have stable processes and fairly similar product may well use standard settings for everything they make. YMMV

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#71564

Profiling | 9 January, 2014

Nicely put, Sfc 'hege

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reflow oven profiler