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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


No clean and f devices

Jeff Tamagi

#8579

No clean and f devices | 11 November, 1999

I have read in some magazine articles that there is poor signal to noise ratio of RF devices when no-cean solder is used.

The frequecies used exceed one Mhz? Is this true?

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#8580

Re: No clean and f devices | 11 November, 1999

Hi Jeff Actually it's not necessarily Signal to Noise Ratio or even RF circuitry. All no cleans leave behind residue by description. This residue can affect RF or other high frequency circuits in a number of different ways including SNR. Very high impedance circuits, very low level circuits and circuits requiring extreme stability may also be affected. A cleaning process is normally required in these cases. The problems will not necessarily show up immediately either. The design Engineer should be providing input into process requirements when the assembly requires it. Hope this helps John Thorup

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#8581

Re: No clean and f devices | 12 November, 1999

Now an than I hear, read about the same thing but without mentioning specific frequencies. It�s something that worries me in the back of my mind but not in actual daily workflow. Our boards go up to 50Mhz with digital bus systems and are made with no clean. I�ve seen some Industrial-PC systems also done with no clean and there seem to be no problem with that. So I also wonder where`s the point of change to solder and wash.

Wolfgang

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#8582

Re: No clean and f devices | 12 November, 1999

Some under-the-hood automotive people have moved from no-clean to clean, and I mean CLEAN, recently.

Hmmmm

Dave F

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