This instructable demonstrates the process for making printed circuit boards with features as small as 0.005 suitable for LQFP or QFN ICs using negative dry film photoresist
This will enable you to handle just about any kind of integrated circuit available–even ball grid array! Pictured are boards with a TSSOP-14, QFN-40 packages using a .65mm pitch and zero insertion force flex sockets with .5mm pitch.
So how does this add up to the greenest instructable around? Well, if adversity is the mother of invention, then guess there’s a lot of inventing going on out there. That’s a good thing, because we’ve had a few wake-up calls recently and could use all the innovation we can get. Today’s semiconductors have matured to the point that any amateur electronics buff can wield the latest system-on-a-chip processor and combine with state-of-the-art sensors to make the cutting-edge control systems necessary to realize so many potential energy saving or energy producing inventions. The tools contained herein can unlock all of the potential these semiconductors embody for the innovators–you and me–that will use them to change the world
After experimenting with home PCB fabbing for a while, I’ve finally worked out a process that produces reasonably consistent results that actually look pretty good. spent lots of time trying to use the toner transfer method with varying degrees of success
If you haven’t tried the toner transfer method, do so. Unless you are blessed with magical toner and/or paper, the dry film resist method will yield better results, but the process is a bit more involved. If you are satisfied with the toner-transfer results, by all means, stick with that method
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