Much like the famous American comedian and actor Rodney Dangerfield, printed circuit boards (PCBs) just "don't get no respect!"
When I was a young lad just starting out in electronics as a hobby, pretty much the only circuit boards I personally got to work with were those that came with do-it-yourself kits. These little scamps were single-sided (you had to use jumper wires where traces wanted to cross), and the tracks were huge by today's standards -- signal tracks were probably a tad under 1/20" wide; power traces were anything up to 3/16" wide; and the ground trace ("plane" is too posh a word) did its best to fill in the gaps. Also, everything regarding the layout of the copper was generally hand-drawn and much more "organic" in those days.
Bottom side of a single-sided circuit board circa 1975.
Of course, life was much simpler then in many ways. The most complex integrated circuits I played with at that time were 14-pin and 16-pin 7400-series TTL chips in DIL (dual-in-line) packages with a 1/10" pin-pitch. Then things started to get more complicated...
I still remember seeing my first double-sided PCB and thinking "Wow, that's cool!" A little later I was exposed to 4-layer boards, with signal traces on the top and bottom sides and embedded ground and power planes in the middle. Also, the signal traces started to become finer and finer.
These days, of course, we have signal traces whose widths are measured in a few thousandths of an inch couple with 1000+ pin devices presented in BGA (ball grid array) packages with a 1mm pitch between pads.
Example of a BGA (ball grid array) breakout.
And, just to make things even more interesting, programmable devices like All Programmable FPGAs allow designers to swap the function of the general-purpose input/output (GPIO) pins. This is wonderful for the design engineers, but perhaps not quite so exhilarating for the board layout designers who are late to discover that the pin-out has been changed. For an example of this, check out the humorous "Dave Goes Nuts" video from Altium:
All of this to say, I think it would be wonderful for us to have a PCB layout expert as a blogger here on All Programmable Planet -- someone who could keep us all abreast of the latest developments in the circuit board world, and also answer any questions we may have when creating our next masterpiece.
What do you think? Do you know anyone who might fit the bill? If so, it would be great if you could ask them to contact me at max.maxfield@ubm.com.
@Brian: Doubtless there will be more fascinating insights into Crusty duality as time goes on.
I suspect in the long far away future, where the machine culture has outlasted mankind, they will be data mining the APP archives and will be able to pin point the fall of humanity, as we know, it to the emergancy of the Crusty syndrome.
@Brian: A gentleman never reveals his supper washing up details were there is a lady involved.
If there is a Mrs Crusty she is more like Mrs Glum as poratrayed in the classic radio comedy Take It From Here, never seen and only heard in the background and only intelligble to Mr Glum.
Max Maxfield 2/18/2013 9:13:46 AM User Rank Blogger
Re: "My Life with the Printed Circuit"
@cpetras: I woudl like to read this book myself. I think the history of the printed circuit board is facinating. Did you know that Thomas Alva Edison (in a letter to a friend) discussed the possibility of using conductive inks to "print" circuits? As I wrote in my book Bebop to the Boolean Boogie:
In 1903, Albert Hanson (a Berliner living in London) obtained a British patent for a number of processes for forming electrical conductors on an insulating base material. One of these described a technique for cutting or stamping traces out of copper foil and then sticking them to the base. Hanson also came up with the idea of double-sided boards and through-holes (which were selectively connected by wires).
In 1913, Arthur Berry filed a British patent for covering a substrate with a layer of copper and selectively etching parts of it away to leave tracks. In another British patent issued in 1925, Charles Ducas described etching, plating up, and even multi-layer circuit boards (including the means of interconnecting the layers) [...]
Max Maxfield 2/18/2013 9:08:15 AM User Rank Blogger
Re: PCB at 1KHz, 1MHz, ... or 5GHz?
@intseeker: I really appreciate your faith in me -- and it's true that, having been around for a long time, I've been exposed to a lot of "stuff" (from laying out boards by hand, to using stripboard and wirewrap, all the way to microwire -- but these days to work with high density interconnect and stuff you have to be doing this all the time -- hence the need for an expert.
I've been reading Dr Eisler's story about his invention of the printed circuit in the UK. He tried to get the radio manufacturers interested, but they objected on the ground that it would put a lot of girls out of work. Back then all the chassis were hand soldered using point ot point wiring.
Duane Benson 2/17/2013 2:58:47 AM User Rank Blogger
Re: Design for manufacturing
Tomii - re: "Did I ever mention that I'm an idiot?"
Welcome to my world. Years ago, when working on an old TV, I discharged the CRT voltage through my handy screwdriver and test lead. Then I shorted the 110 AC input wires, discovering that the set was still plugged into the wall. These days, my stupidity generally shows up in things like using the wrong component footprint on one of my boards, or using a non-compatible pin-compatible part, like voltage regulators. They all look the same, but some have different pin-outs.
I also, apparently, like to put LEDs and caps on backwards now and then.
When I started to read the blog proposal, what went through my mind was: "What is this guy talking about? He was my PCB expert! He even though me a class at the Digi-Key Contonuing Education Center!".
As I proceded, it striked me that when distances become microscopic and operating frequencies sky-rock to microwave range, we may need a highly qualified microwave engineer or a 21 century IC engineer to answer all our questions, don't you think?
Remember micro-strips of 70s and 80s? How many of us were solving Maxwell equations outside a ressonant cavity or a micro-wave enclosure? When I was teachinch undergrad MW engineering and I told my colleagues I was trying to introduce micro-strips in the curriculum, they though I was nuts!
We may have to refine Max's proposed Job Description. :o)
If Max doesn't want to be my PCB guru, I will check with my colleague Márcio C. Schneider (Doctorate in IC and runs a graduate school research lab) would take the job. Unless you tell me not to.
@Max: More importantly, Cuusty still talks about himself in the third person...
Max finds this disturbing :-)
Crusty agrees, Crusty has a split personality hence the use of this avatar. Maybe my attemps to programme / organise FPGA's suffer from this dual personality?
We consider complementary versus analogous colors and the meaning of terms like shade, tint, and hue. We also introduce the concept of psychological primary colors.
The appellation "primary colors" refers to a small collection of colors that can be combined to form a range of additional colors, but which "small collection of colors" should we use as our primaries?
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