| Do anyone have any experience on assembling high frequency product, 1.8GHz or 2.4GHz. | | In our production line, we manufacture 1.8GHz product with using no clean paste (RMA type) for reflow and no clean wire for rework. In our functinal test,either at 25degC or 50degC, no malfunction is observed. | | However when switch to 2.4GHz product,we encounter malfunction of the product at 50deg C. The paste we are using is also a no clean one, but of ca.100ppm halide. I just wonder the dielectric constant of the flux residue will vary with the test temp!? | | I look up some test book, it state for RF product, cleaning is required, is it true? | | Dear all, do you have any comment? Thanks in advance | Hmmm....sounds like someone is working with the new SiGe wireless-LAN chipsets.
I know others out there will not necessarily agree with me, but here goes....
In the frequency ranges you are working in, I personally would never ship uncleaned product.
RF is a funny world. You can nail down your processes tighter than a drum skin.....only to run up against what can only be referred to as the vodoo and black magic which is embedded with the RF monster. Yes, we've come a long way. But as much as technology has advanced, there is still art involved in designing and building RF products. A really good RF design and test engineer names their own price these days......
Using RMA no-cleans, I've done Joe Keller's recommended test using distilled water and voltage application across the traces on RF product before--hello dendritic growth.
If you'd like the test parameters, I can dig them up out of a box in my barn.......
Scott
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