Electronic – Making prototypes with high speed SMD components

high speedpcbprototypingsurface-mount

Even today we have breadboard and strip board on which one can make "quick and dirty" circuits and also test prototypes. However, we have now moved into an era of predominantly surface mount components many of which work at very high frequencies.

If one wants to make a circuit one may first need to design some simpler prototypes of fully understand how the complex off the shelf ICs work and determine their performance, sometimes we may find that the datasheets are wrong too. In this process if we find that a connection was wrong or the chip was fried, we can rewire/replace them easily when we have a strip board or veroboard, we can always use a breakout board for surface mount devices to generate pins from them.

However, for circuits that work and high speeds, doing so is not possible anymore. How does one follow the prototype stage in this case? It seems that the process will become longer and more expensive and rather inconvenient if PCBs have to be respinned many times.

Best Answer

There are techniques that can be used for prototyping. If you're prototyping a whole system you're probably not doing it right- but to test smallish bits of analogish circuitry, it's practical. It's good to go to a PCB layout early, but not necessarily as the first step.

Here's one hacked together circuit by a fellow I happen to know John Larkin- (he's since moved to gold-plated for the boards)

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And another (the high-speed section is kept very small)

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This is done with shears, dental burrs etc. The ground planes under everything mean that the circuits are fairly quiet. You can also stack breakout boards for SMT chips on the ground planes (you can buy them or have your own made).