I don't see layout designers losing their jobs. If anything, layout is getting more challenging, and a good layout guy is essential. I scoff at the notion of CAD tools that will make layout automatic, or that circuit designers will all start doing layouts too.
I've seen job postings lately requiring circuit design and circuit board design skills. I doubt that many experienced circuit designers, except maybe in very small companies, have that combination of skills. When I see that I pass that job by.
Like you, I too started when you gave your hand drawn schematic to the drafting department where they would make the schematic look nice. Then someone else in the drafting department did your PCB layout using red and cyan tape on clear acetate.
A few years later, you gave your schematic blueprint to a technician who extracted the net list by hand into a text editor. The net list was then input into the CAD system where a design house (in my case associated with the PCB fab company) routed the PCB using a Calay system. As the designer, your main input was this is the outline, here are the connector locations, and put these chips over here and those over there. (These were big all TTL panels.)
Then OrCad (and Pcad, and Pads, etc.) came along. You could do your schematics and layouts on your own desk. Over the last 20 years or so I've worked at tiny to smallish companies. For all but the simplest circuits, I've always designed my circuits and laid out my own PCB's. Everyone else I know generally does the same thing.
I've always considered the PCB part of the circuit design and I want to make sure all the signals and grounds get routed correctly. The PCB layout is part of the circuit especially for RF designs but it is also for power supplies which you want to not emit RF. The same is true for fast digital boards. And for very low noise, low power analog you want it to not be susceptible to RF. Actually you have to consider EMI and RFI for pretty much everything except for maybe the simplest embedded PCB with a PIC, a linear regulator and a few simple peripherals.
Everyone has heard the stories of handing a design off to a layout person and getting the board layout back with all the bypass caps grouped together in one corner... Recently I was at a place where for time reasons they farmed out the layout. It had lots of mechanical positioning constraints. It took so much time to convey all the information to them and so many back and forth phone meetings, the designer could have just done it himself in less time. On the other hand, maybe it was that particular layout house, there's another I know here that does well.
I did contract work at a large company for a bit a few years ago and they handed off the layout to the layout department. While I was there, I watched the layout guy spend days editing the locations of few caps. Maybe big companies can afford to hire dedicated layout people who understand all the nuances of both good layout practices and circuit design and are not just hooking up black boxes, but at small companies the designers do the layouts in my experience.
Everyone has heard the stories of handing a design off to a layout person and getting the board layout back with all the bypass caps grouped together in one corner...
I wonder if anyone on thsi thread can categorically say they've actually seen this...
Stems from the engineering habit of guessing how many bypass caps will be needed and placing them all in parallel on a single schematic page. A good way around this is to place a 1 ohm resistor in series with each IC power pin (assuming your schematic symbols are designed to let you do this), followed by the decoupling cap.
Even then things can go wrong. Make sure the layout person understands that the caps have to be physically located right at the power pins and that each cap must have a very short trace to the ground plane via. Running several long traces to a shared via ground (to minimize the cost of drilling) is absolutely forbidden - one has just taken a SMT chip capacitor and turned it into a leaded component with drastically lowered SRF.
If the layout person cannot compregend the rules then it is best for the circuit designer to lay out the PCB hirself, or at least sit side-by-side with the layout person and micro-direct.
I see few openings for just PCB design nowadays. Maybe I am not looking hard enough, but over the years PCB design has become increasingly complex and the tools more integrated and sophisticated.
The idea that PCB design can be automated has always been absurd, but this notion persists amongst some management circles. Moreover, autorouters have given way to routing-assist algorythms. Engineers today have more tools to assist them in developing a product, but it still takes a team of professionals to make real money and the cost of doing so are increasing.
I have been many things in my engineering career, and now I am considered a Hardware engineer. I design circuits and perform PCB design. It is my responsibility to get fuctioning hardware into the hands of a software team that will polish it into a real product.
Who designs the PCB and what their role and credentials are may depend on the industry in question, but it appears there are far more degreed engineers doing this work today than in the past.
Unfrtunately, these individuals often have little knowlege of drafting standards and give little thought to information transfer and reuse.
@Carl: I don't see layout designers losing their jobs.
I didn't say anything about layout designers losing their jobs -- my point is that a lot of the older ones are moving toward retirement and there's no formal path (or seeming desire) for younger folks to enter this arena
Max, I personally think that layout design is as important as the circuit design. A badly placed track in a audio power amplifer can dramatically increase THD or hum or even channel crosstalk and in digital designs EMI and a lot of other aspects can be adversley affected by bad layout. It's basically a case of teh PCB being an important part of the design. You need to be an RF capable engineer (even if only in skill set) for a modern RF board.
I remember 30 years ago passing a microcontroller based telephony I/F schematic to a design house for layout and we were later puzzled by the micro resetting when it turned on the switchmode power supply. This was because the inrush current to switcher produced a negative 10V glitch in the adlacent ground lead to the micro such that it saw 15V for a microsecond. This put it into latchup resulting in it shunting the 5V supply. A micro that normally drew 3mA was drawing almost an Amp until power was cycled. The PCB just wasn't "engineered"
I draw my schematics with the PCB in mind even doing design calculations of how many Watts I can disipate in my available board area, and track PCB impedances for clock lines or other lines with sharp rise times.
I then always do the layout myself because it is such an integral part of the design.
I struggle with being able to put enough information in the schematic without creating a situation where there are more PCB annotations than components :-)
I don't think layout designers are becomming extincted so much, but rather those without a good understanding of the engineering aspects of it are being replaced by actual engineers that enjoy the physical design process.
>> I agree -- you can't have one without the other.
Actually, thinking about it, that's not strictly true -- you can't have the layout design without first having the circuit design -- but you can have the circuit design without having a layout design ... you just look rather silly :-)
Max, I agree with this statement completely. It's not about taking work away from layout designers, rather it's about facing the reality that the first generation of layout designers (who began in the 60s and 70s) are retiring AND the demand for pcb design work is increasing. First generation layout designers have valuable experience and have developed techniques over the years that cannot be learned quickly and easily. I believe it is the role of software companies to understand these methods and to develop sophisticated software that can empower less experienced designers and even circuit engineers with tools that will automatically accomplish the same end. I'm not talking about autorouting, rather tools in the interactive environment that enable user control, quality and performance.
@Charles: I'm not talking about autorouting, rather tools in the interactive environment that enable user control, quality and performance.
I have to say that the Sketch Routing feature in Mentor's latest offering pretty much blew me away -- the one where you use the mouse to draw a vague "swoosh" that both indicates the traces you are talking about and the general way in which you wish them to be routed ... and the system takes over and does it -- very impressive...
I have worked in military and aerospace requirements.
I have worked at dot com startups...
I currently have my own company.
Each situation has it's own requirements.
Large companies.. people will be compartmentalized/specialized in their job. Generalist (master of many skills) will not be tolerated or encouraged in this environment. These companies will have resources and reasons to push the bleading edge of technology. These companies will have dedicated pcb layout designers. The cost of extra layers of communications/ quality checks (CYA activities)/etc. are expected and tolerated. But the speed of idea to physical example is generally slow. Each sign off signature for a design change costing 1 day - 2 weeks (he was on vacation) often with 6 signatures required.
Once they FINALLY approve something.. they can assign armies to move the project quickly.
Great ... if the product definition is stationary or slow moving. And a lot of engineers like the idea of sharing the responsibility of a product's success (or failure). There is less personal risk involved.
Small companies.... speed and efficiency is King. Fast turn around is more important than "getting it right the first time" (while it is still important). Reason? because it recognized that the product definition will likely change before the product can be built. With a tightly coupled design/layout/manufacturing I have seen complex 10 layer ,4mil line/space, high freq designs completing all of these phases - idea, schematics, pcb layout, fab and prototype built on automated production line - in less than 5 working days (using 3 day pcb turn). And it worked great. This is only possible because of the newest CAD tools and a willingness of the employee to wear multiple hats. The engineer involved MUST be the pcb designer/mechanical engineer/manufacturing process engineer. Not all engineers are up to the task or are willing to become proficent in all the areas required. Indeed, many engineers don't believe it can be done with any real quality (I am NOT of this camp).
A large number of engineers are lost without their technician! or their pcb designer!
For the company or project... RISC or CISC based work flow?
For you ...Generalist or Specialist.. what are you?
(or more accurately... what percentage are you?)
You have to understand enough about yourself to recognize which environment you feel most comfortable.
I don't see a single solution/process for all companies, because I don't see a 'one size fits all' engineering talent pool. So, pcb designers will be around for awhile yet.
@Thinking: I don't see a single solution/process for all companies, because I don't see a 'one size fits all' engineering talent pool. So, pcb designers will be around for awhile yet.
I think their prospects are better than "will be around for a while yet" ... the way electronic designs are moving, I think that really good layout designers will be recognized as the artists and experts they are, and they will be worth their weight in gold (although they will continue to be paid in peanuts as is traditional LOL)
I was around back in the day of taped boards, too. A good PCB layout person knows how to deal with the mechanical issues, as well as today's PCB manufacturing issues, that most electronics design engineers rarely deal with. Several years ago, I worked as a consultant at a small company that thought the design engineers would save time and money by doing the layout themselves. I had no training in the layout tool, and I suggested that while I wouldn't mind learning how to do layouts on their $$ (at my consultant rate), it would probably be cheaper to bring in a PCB designer. We updated a large system connector board, with dozens of connectors consisting of several different varieties. The PCB designer asked if there was a reason the company-made connector footprints had the drill holes off-center -- the footprint appeared normal, but the drill data showed the offset (and not normally shown during layout). I said I didn't think so -- could it be easily fixed? He quickly fixed the problems and the board was built as planned. The original board took nearly a full day to assemble by hand, because the mechanical problems caused by the drill offsets required a special order, e.g. install CON1-3, stuff CON4,5, mate with metal plate, solder CON 4,5, remove plate, etc. It was like taking all day to build a sandwich. With the expertise of the PCB designer and his use of industry standard techniques, the assembly was cut to 90 min -- most of which was applying a special metalicized tape for shielding. The metal plate slipped over the connectors and was easily fastened to the fully assembled board in minutes. That was the end of letting the design engineers do it themselves. When management doesn't know how to quantify what a PCB designer can do for them, they think electronics design engineers can do it and save money. That may be true sometimes, but not nearly as often as management thinks!
@Ducksoup: ...With the expertise of the PCB designer and his use of industry standard techniques, the assembly was cut to 90 min...
It's this sort of expertise that you can't "bottle" (unfortunately) -- this is why people who do dry walls for a living can do it so much better and faster than people who don't -- similarly for plastering walls or laying tiles or whatever.
Of course this is also why we don't let the layout designers design the circuits in the first place LOL
Having also got my start in board layouts using tape and photo-reduced artwork, the advent of the lower cost PC based solutions did usher in an era where the circuit designer was also the PCB designer. Once CPU clock speeds passed 500 MHz , and once devices had over 300 contacts, then the circuit designer would hand off the desgin to the PCB designer. The time needed to stay current with the PCB design tools ( and work arounds to all their problems) is time that most engineers do not have. Let alone all the PCB fab advances that seem to occur every 6 months or so, it is very easy to fall behind. IF your designs contain mostly standard parts and are less than 50 IC's, the circuit designer can do the PCB design. BUT if you have large QFN or BGA's and high frequency operation, it almost ALWAYS better to allow an experienced PCB designer do the work.
Was working as an engineer at my first real job at a small oem. You did the circuit design and taped the PCB layout ( 4X size!) then had it photo reduced to send to the PCB fab house. Of course designs were mostly .3" dips with a few larger for the CPU and peripheral controllers and usually not a high parts count AND only 2 layers. It was just expected that you would do both jobs. Made you appreciate the early CAD programs. I still remember using VAMP on the Mac in the early 80's in greyscale colors. And my first real PCB layout software was GE Calma running on an Apollo workstation.
Great insight!! I wasn't around pre-CAD days so it's always interesting for me to learn and appreciate how things were done.
As one of commenters mentioned earlier, I think that it depends on the environment. I work at a small design house. I am expected to wear many hats ranging from circuit design to FPGA, SW, mechanical, and sometimes layout. And I love it!!
However, the typical 'flow' in our company has you at schematic entry or board-bring up for one design, while supporting the layout designer on a previous schematic that you worked on. This flow keeps engineers in the design and test phases, while the layout designers complete the layouts at a very high efficiency.
Looking at it from another perspective, designs are becoming more complex. Materials are becoming more complex. And manufacturing processes, well they will have to follow. I think, and this is just an opinion, that as the tools get better, the layout designers will spend less time routing, and more time understanding and dealing with the manufacturing process. This might create an opprutunity for layout designers to become more integrated in the product development phase than before.
So I think that the layout designer will be arround for quite sometime. The role and scope of work might change. Didn't we think that they would disappear with the auto-router?? :)
Wearing a whole shop of hats (SW ... semiconductor physical design) and having finished 2 PCB designs today (only the "consulting/support portion - the PCB layout designer was sitting 2xx km away - remotely controlled via phone):
Functional layout requires the circuit designer sitting next to the layout designer as most "pure" layout designers I learned to know in the past 2 decades did not fully comprehend the functional restrictions of the circuits they were laying out. This typically results in unwanted crosstalk and other cruelties.
Layout topics like power supply layout, EMC/EMI robustness and the like are better addressed by people who do this on a regular basis (> 4 times/year) and who do also understand the impact of layout tradeoffs etc. - especially in terms of emissions.
AND: manufacturability topics etc. require regular and frequent feedback from production - typically not addressed to the circuit designer.
Even the singular topic "copper placement" requires quite a number of hats. Some of them can be worn by a PCB layouter, some hardly. Good layouts tend to be the result of a team - including the guy doing the "lowly work". And yes: paid in peanuts :)
As a (somewhat) younger wearer of many hats, I am very grateful for the opportunity of working in a smaller company, and learning how to be a part of many different teams. I enjoy bringing in interns and helping them learn some PCB design, and then doing the same thing that I was allowed to do... define my own project. Meaning I was able to take an idea that my company was tossing around at the time and run with it from schematic to PCB and firmware prototyping. It was an incredible learning opportunity, and has continued to be a source of inspiration as I work with other college aged interns.
On a slightly different topic I am wondering about tradeshows and education. I have been to IPC APEX expo, and PCB West, but feel like I would benefit from the something different. Anyone have experience with IEEE MWSCAS or EMC symposium?
I certainly don't want to see PCB layout designers as an endangered species, but am also thinking about the other end of this problem namely how do we make it easy for more people to get comfortable designing PCBs. With all the recent growth and commerce around the "Maker Movement" (and I'm an enthusiastic participant), we still haven't done much to make the PCB part of the creative process easy. I don't have the data but I'll bet there are a lot of makers who comforably crank through the design and prototyping part of the process with great tools like Arduino, pre-built shields, breadboards, etc. and then grind to a halt because of the steep learning curve associated with PCB design and associated tools.
I've tilted at this windmill several times myself with Eagle, various on-line design sites, etc. Not only are the tools tricky to figure out (and the tricks are hard to remember once you've learned them if you don't make boards all the time), but the part libraries are widely scattered and inconsistent. I regularly search for "learn to build your PCB" classes at dojos like TechShop without any success. There are some good on-line videos, and even an on-line class or too but I keep coming back to the whole process being too hard for people to feel good making their first board.
Perhaps it won't solve the problem at the serious professional end of the scale, but I'd like to see us get more people with good basic PCB fluency in broad end of the funnel. At least perhaps then there'd be greater appreciation for the art of (and need for) sophisticated PCB design.
@Disquisitioner: ...how do we make it easy for more people to get comfortable designing PCBs.
I can't speak for the medium and high-end tools, but -- as I noted in yesterday's PCB Designline newsletter:
I saw the most amazing tool targeted at the Arduino user. This little rascal (the tool, not the Arduino user) provides you with a graphical view of an Arduino and associated breadboard. You drag-and-drop components onto the breadboard and then add wires connecting everything together. Next, you create your Arduino sketch (your C/C++ program) and simulate it on the PC, with LEDs and things lighting up on your virtual breadboard. Finally, your design is exported into a PCB layout package in which you perform the layout, and then you upload your design to a board shop for fabrication.
I'll be blogging about this later today or tomorrow ... watch this space...
@MaxTheMagnificent: Cool, I'll keep an eye on this space (but then I *always* keep an eye on this space :-). Hopefully the simulation environment doesn't get in the way of PCB creation. I'd be truly impressed if someone has built an Arduino simulator that can handle all the external components and breakout boards I routinely use as well as the programming techniques commonly required (interrupts, PROGMEM, etc.).
Given I'm going to need to build and test the whole project anyhow I'd be happy if the rascal tool just let you say "this is an 8 pin DIP with these lines carrying TTL data and these are power and ground" and "this is a power transistor so these lines carry 2A", etc., and then from there generated the basic PCB layout. I don't really need the tool to know that the 8 pin DIP is a 7 channel graphic equalizer display filter and simulate same...
Disquitioner asked: how do we make it easy for more people to get comfortable designing PCBs?
Oh, I'm fine with designing PC boards. The problem is that all the interesting components are too fine-pitched for me to solder. So for my own work I buy (or get as swag) modules with 0.1" spaced wire-wrap posts, which I then wire-wrap together on a perf board (with ground plane and twisted pair clocks) or use a solderless breadboard for quick experiments. I like the irony that I'm dealing with the continual rapid changes in technology by using breadboards and wire-wrap wire from my high school and undergraduate days. Le plus ça change, and all that stuff.
I've seen the future, and it is us. The new Mentor Graphics Sketch Router is a significant improvement on what has come before, but it still relies on the massively parallel processor of the human brain to make it work in tough jobs. If you put a peg in the ground and say "This is as far as technology goes" then auto routers will catch up eventually and board designers will become floor sweeping janitors. However the technology keeps changing, morphing into ever newer combinations of ever newer chip technologies to provide ever newer functionality to ever newer devices at both consumer and professional levels.
During idle time waiting for a transistor post trades course in 1969, I read an EDN article that stated unequivocally that printed circuit boards will become so simple that all they will need to do is provide power, ground and input/output connections because all the smarts are going to be encapsulated in complex silicon. I was impressed, until I saw the real world of discretes becoming simple ICs becoming complex ICs becoming Large Scale Integration becoming Very Large Scale Integration and so on. Board interconnects became exponentially more complex as chips became more complex. Add serious signal integrity issues as rise and fall times became ever faster, and you have a perfect storm of a parallel processing human brain using complex serial tools to solve almost insurmountable interconnect problems.
I believe board designers are not going to go away any time soon. They'll just transform themselves into ever-evolving experts.
And will qualified EEs take over routing boards because of their 'expert' knowledge? I doubt it – I don't know a single EE that knows what he's doing wanting to replace his delight in designing complex schematics to then take on the mundane business of 'connecting the dots', all the while being aware of the myriad fabrication and assembly issues that separate the men form the wannabes. I'm currently working in an area that is at a cutting edge in High Frequency Trading, with some really smart (and young) engineers that have a seriously tight grip on technology. At age 66 I'm a big part of the team, and we work together with individual skills that add huge synergy to making complex designs work. I suspect it will be ever thus.
There, my two cents worth.
Andy Kowalewski, board designer for 34 years, grey hair, working long hours, still loving every bit of it.
Tools will continue to evolve. But I don't see them as a replacement for knowledgable designers)
Schematics? a lousy method to define all the aspects of a circuit being made on a planar surface (FR4, Teflon, ceramic, etc..). Schematics are to convey infomation about the operation of the circuit to others. Sure, it can create a connection list (net list) .. but a simple text file can convey this directly. No, a schematic graphically informs other engineers, techicians HOW the circuit works.
For most of us.. it is the only tool we have... so it becomes a "catch all" for informing the pcb designer how we want the board to be laid out. A bad plan.
This is the reason why:
- Good EEs learn pcb layout tools and manufacturing requirments. Even if they don't become proficent in these other areas, it will help them create optimum work flows within their teams.
- Good PCB designers know something about physics and EE design. (besides manufacturing and layout tools. It is requirement to do their work well.
And why the schematic shouldn't tell the pcb designer ...where to place de-coupling caps. A good pcb designer should already know.
@Thinking_J Schematics? a lousy method to define all the aspects of a circuit being made on a planar surface
There was a time when the pcb layout designer would read the hand-drawn schematic from the circuit designer and proceed with the tape-up.
Then the system was 'improved' with CAD tools. We still drew schematics by hand, but created a netlist by hanging the D-size blueprints on the walls and ran around with yellow markers calling out nets and pin numbers for a scribe to write down. The pcb designer used this netlist to design the layout. I was shocked when learning this system and told that the pcb designer never even looked at the schematic, so there was no point placing notes on it as was my habit.
Then things got worse as the schematic tools became software driven - proved many times the old adage that "to really foul things up you need a computer". (Fortunately things have improved since.)
Better schematic tools allowed the circuit designer to specify trace widths for particular nets, but could not distinguish between the main current-carrying bus and a tap to an IC power pin. You are right - the schematic shows how something is supposed to work, and translation into a properly-designed pcb takes skilled effort - not an autorouter. But it's the onlly tool we got.
@THinking_J And why the schematic shouldn't tell the pcb designer ...where to place de-coupling caps. A good pcb designer should already know.
Very true; but there is no guarantee that the layout designer assigned to your project is a good one. Ever since CAD netlists and rats' nest displays encouraged a "connect the dots" methodology many (mainly management types) think PCB layout is easy and are not aware of the additional skills and experience that are still needed.
Forced placement of bypass caps as a result of the schematic can prevent nasty surprises later.
zeeglen...I understand why it is done (explaining where to put decoupling caps)
Just like I understand (But don't agree with):
- making schematic symbols that look like pcb shapes.
- explaining / or expecting the production supply chain/ to "know" the impedances of DDR2 or DDR3 signals within a schematic.
- or explaining good (basic) layout practices for switching power supplies.
- or explaining how to recognise and layout tank (resonate) circuits
- or explaining good emi/rfi practices...
The point: If we can't make the schematic specify EVERTHING about the pcb design, why make it hard to read for it's intended audience? For the sake of covering just a few of the issues because we can't trust HR to hire good pcb designers? (at least they got the de-coupling caps right.. the rest of the layout was poor).
I acknowlege each of us will pick the battles we think we can win within a given organization.. and sucume to poor work arounds when forced to.
When someone is trouble shooting a design (years later).. the primary documentation they should look to is the schematic. For me, this person (tech) is the primary customer the schematic is made for. They aren't going to be trying to re-layout the design. They want to know how the product was supposed to function. It is likely they won't have the production tools (test fixtures, text instructions, access to the engineer(s), etc...) and may be happy they at least have a schematic.
I could be pointing at windmills .. maybe everyone expects their design to be completely un-supportable after production stops. A result of "throw away" technology becoming so prevalant.
Does anyone remember the schematics that came with Heathkit products from the 60s and 70s?
They included operational notes , expected voltages , expected waveforms - all in the schematic. They were made for novice trying to understand what they were building. (I am not advocating this level of detail in all schematics) Very little about physical layout. They were "art" (defined by: adding or substracting only reduced their level of perfection).
Perfection because they clearly understood their audience. Do we think of our audience is pcb designer? or the tech supporting the product years later?
When was the last time you looked at a schematic and thought... "art"?
Does anyone remember the schematics that came with Heathkit products from the 60s and 70s?
Yes, in my younger years I worked at a Heathkit retail store and built dozens of store display models at home. Very logically and clearly drawn, and the circuit descriptions were great. Even now my work is influenced by those early Heathkit years; I try to draw new schematics clearly; and write detailed circuit descriptions for colleagues and techs even though they (for some strange reason) are usually not required in the project plans set by manageers.
When someone is trouble shooting a design (years later).. the primary documentation they should look to is the schematic. For me, this person (tech) is the primary customer the schematic is made for.
So true, when CAD schematic capture first started the emphasis was on turning it into a netlist; the concept that someone might later use it for debug seemed to have been overlooked. Simple things like drawing a diode bridge at 45 degrees, or placing a slight slope to a wire end 'pointing' to the other end of the same wire on the opposite side of the page. Or drawing a basic timing diagram with text notes. Early CAD would not allow that - I hated it!
A good example is a company I once worked for inverted the Cadence grid location borders to match company standards. But they overlooked the off-page references, so trying to follow connections between pages one had to remember that the off-page designations were mirror-imaged and vertically flipped from the border grid.
They included operational notes , expected voltages , expected waveforms - all in the schematic.
The drawing package I currently use allows exactly that - I can place simulations and scope captures directly onto the schematic. CAD has made much progress.
Do we think of our audience is pcb designer? or the tech supporting the product years later?
Usually the PCB designer does not even look at the schematic. Hesh follows the stack-up dimensions documents.
When was the last time you looked at a schematic and thought... "art"?
Every time I see a well-drawn schematic. Actually a while back there was an article in EE Times about art in electronics and schematics, can't find it.
(But don't agree with): - making schematic symbols that look like pcb shapes.
This depends on the purpose of the schematic. I do a lot of reverse engineering in that I take unknown boards and turn them back into schematics. The first pass is very physical, components on the schematic are placed in the same relative position as they occur on the pcb, color coded as to which side they are located. Integrated circuits are drawn in their pcb shapes with the logic elements shown inside. Then I take sections and turn them into logical schematics that show the circuit functionality.
Thinking_J: I don't think I've designed with a real nand gate since the early 1980's. TTL octal buffers and latches yes, logic no. Everything in the 80's was TI or MMI PLD's after I bought my Structured Designs programmer. Quickly migrated to bigger PLD's and FPGA's after that, simply to reduce board area, cost, and improve ability to apply ECO's to the design without extensive rework.
Most client designs reflect the same.
I've also designed around stocked, or easily sourced parts, doing the PCB layout first, by what is easily placed/routed on the board keeping in mind signal integrity. Then keeping the Schematic current so that the designs netlist is synced between the schematic and pcb tools.
With PLD/FPGA designs this helps simplify the pcb design because pin placement is a function of layout, and avoids horrible trace routing from poor pin assignments.
It's frequently better to layout control/data bus traces first between parts, then assign pins/functions to keep the traces net flat with no/minimal vias. I normally avoid strict manhatten layouts, carefully using any direction "flows" for buses, end to end on the same layer, making sure to leave space for control signals.
This flow allows choosing parts to make the layout smaller, faster, easier ... and avoids the trap of trying to layout from schematic, parts that do not easily fit on boards, creating a nightmare of vias to invert/descramble connections that are not flat/via-less
John_Bass. you are right, a lot of design work will never require a individual gate. I too have used programmable logic as you have described for many of the same reasons.
But individual gates are still used - I certainly wouldn't put in a programmable logic part when only one gate was required. A recent design I worked on, a TI Sitara 1GHZ, Cortex A7 processor design required a single gate for interaction between the processor and the power regulator specifically designed for this processor. No need for any programmable logic anywhere else in the design. Please don't ask me to explain why they couldn't have elimiinated this requirement.
The point I am trying to make: the schematic symbols for logic of any type, should NOT try to represent the pcb shape or pcb layout. It SHOULD try to represent the best way of conveying the function of the circuitry.
Granted, programmable logicc is problematic. Blocks representing the power and special purpose pins are easy enough to keep separate from the rest of the "logic" when creating a schematic symbol. But the best way to represent the logic could be very different on products. (same IC on different designs).. few of us want to create different symbols for the same part - based on the usage. Still , it can be done.
I get requests for processor pins that have 17 different functions.. to be identified ON THE SCHEMATIC SYMBOL ... which function will be used on a given schematic (yes , a different schematic symbol for each usage of the part). The identified Signal using the pins ..is not enough documentation for some.
While you often can improve the layout on a pcb by forcing pin choices on a programmable logic device, often this will be at the expense of performance (internal) of the device. Altera, Xilinix, etc.. most will recommend letting their software select pin assignments to optimize their performance.
There is no one right answer for all situations.
The customers for the "schematic" (future engineering support, test dept, repair tech)...is a very different customer from the "pcb layout" (pcb designer,) or purchasing ( layer count , pcb area, drill hole count, etc), or manufacturing (ease of assembly with processes available, component selection based on a pricing and availability), component placement based on thermal/mechanical considerations of the product. The list of issues to consider is large.
To really do the job "right".. requires consideration of all these customers/departments. Your work is judged by all of them.
I assume none of the preferences from each of these "customers" will remain stationary... making our jobs that much harder (sigh).
Of couse, we could just "blow off" the concerns of others (we know best)..
Think_j: I think I would still use a low cost PLD for a single gate, simply to have the extra unused outputs and inputs available on the board for ECO's or semi-custom variations of the design that can do some signal management of inputs/outputs as needed. It's much easier to stock PLD SKU's, than a wide assortment of TTL in the long term. Every company has different views and requirements on this.
There are single and double "definable" gates from several suppliers. They cost pennies and are SOT-23 in size and 6 pin micro BGAs. You can define their gate "function" at the time of installation (http://www.ti.com/lit/ds/symlink/sn74aup1g57.pdf) I am sure they are cheaper, lower in power and smaller than any PLD option. Heck, why use a PLD? why not a micro controller ( they are certainly getting very ,very small, fast and very , very cheap).
I know a lot of companies that would prefer they didn't have to keep both C/C++ programmers AND programmers that work exclusively in programmable logic tools. I know a few C/C++ programmers that would like to take back control of that programmable block - without having to learn another tool set.
We have so many options today.
I understand why you may want to have some excess / spare circuitry because the product has not been completely defined, may want some design re-use (modularity) or as a simple CYA (cover your A...) for the unexpected.
Lower volume products (less than 5K/year).. mmm OK, sure. makes sense.
Often flexibly and design re-use trumps cost/space/power choices.
But.. I wouldn't assume this to be a "best" practice to be recommended to others.
Henry Ford's definition of a engineer: "A engineer does with one dollar what any fool can do with two dollars".
This is a good philosophy for NEW designs. Unfortunately, there are some cases where it won't work.
It's becoming difficult to find PLDs and most newer CLPDs and FPGAs are not 5V tolerant. So when I had to add a fast (<4ns) buffer to use as a level translater from 5V to 3.3V, the only thing I could find that would work were some single gate parts.
I recently had to replace an FPGA that became obsolete with a newer part. Not only were the pacakges and pinouts incompaible but since the new part was not 5V tolerant, I had to add buffers (with logic to switch the buffer direction) that weren't required in the original design.
This is the kind of thing that happens when you work for a company that's still building products designed when almost all logic wa 5V
elizabethsimon: ATF16V8CZ are 5V and have been easy to source from multiple distributors. At $1-2 they are cheap enough, sink 24ma, source 4ma. Buffer with a high current octal ttl part for more drive.
Not to say they will be around long, EOL is striking a lot of 5v PLD parts. One of those parts worth buying up a long supply ... cheap enough, and worth it long term.
I've used single-gate chips recently. They're very nice for I/O modules where you need the drive current and/or protection you can't get from a PLD. They're also nice as part-stuffing options, for example when you have several different kinds of copper and/or fiber interfaces and some need active-high signals and some need active-low.
NXP has some versatile 6-pin configurable logic gates. You get different functions by connecting your signals to different pins and/or strapping pins to +V or ground. This lets you get a lot of different functions without stocking a lot of different parts.
Multi-sourced, and a nice attribute of these configurable logic gates is their Schmitt inputs. This allows them to be used as various types of timed pulse generators by placing an RC network at one input.
Thinking_J asked: When was the last time you looked at a schematic and thought... "art"?
Well, pretty much whenever I look at a schematic drawn by me :-)
Heathkit schematics are superb. But then, they were designed to be used by many, many people so was worth the time to make them excellent.
I like to have schematic symbols match the physical pinout. [update: I'm referring to complex ICs and connectors, not circuit elements or gates.] When I'm drawing a schematic for a product, I'm going to be using it many, many times when debugging the board and its programmable logic. The latter is very important, because even though the board is going to be correct the first time or within a couple of iterations, the board may need to be probed every time a new feature is added to the FPGA. I like to have the FPGA schematic symbol and pins match up with the physical pins if it's a QFP. It makes debugging ever so much more pleasant and the small amount of time invested in creating a useful schematic symbol pays for itself very quickly at debug time.
With BGAs, I like to make a separate symbol for power and dedicated balls, and then have the schematic pins match up with the I/O pad order inside the FPGA.
Another thing I do is to number components sequentially through multiple sheets. If there are multiple copies of an I/O port or daughter board connectors, I like the corresponding components to have similar names, e.g., a series resistor R34 for port A is R44 for port B and R54 for port C, etc. I may skip component numbers so I can make the names similar.
Often I have to work with schematics drawn by someone who used automatic component numbering to assign component names automatically. Sure, this saves a day drawing the schematic, but makes it really hard to find components in the schematics or on the board later on. It's a pain to have a node with pull-up resistor R11 and pull-down R317, instead of R11A and R11B.
For the last decade I have been a single person shop. Making and coding complete embedded designs that relate to audio/video or what most would call robotics.
I would guess that possibly as much as 40 to 60 percent of my time is spent in the board layout programs. Most of the time I do work as a Layout designer.
I typically use the free or limited tools, such as expressPCB, KiCad and Eagle. I also work with legacy designs from OrCad and Pads. In a perfect world I would use Altium. None of my clients have the budget for that.
Like many I have been designing since the rub on transfer days. I was actually taking art classes, with the EET classes as a fall back for remunerative work. This was 35 or so years ago.
My first job was selling computers (Apple/// and Lisas the high end stuff.) When computers became commodity items t I worked for a Temp agency. All of the jobs required typing in the lists that the so called designers were not good at.
I was a terrible typist, but fell naturally into using a mouse. It was not easy getting others to understand that CAD/Cam and especially photo plotting requires special skills. I finally found a niche design testing Laser printers.
Then I took up high temperature enamel painting and metal etching as a hobbie (glass on metal) These processed are not unlike board design.
There was another group of technicians at apple what were into early embedded system. At the time we had access to scrap materials for robot projects. It was watching the layout designers and the layout mistakes that I learned to rework SMT devices.
SMT practically demands the use of a layout package. This was all in the late 1990s.
I typically make about 3 manufactured board layouts a year. Have been doing such for 14 years, that is a lot of board prototypes.
Too me this comes second nature. I suppose that if others like myself make it look easy then it could look like anyone can design boards. Reading the comments here and the articles in the popular press that artists have different brain structures, this may be the case.
It could be that we have been attempting to shoe horn and train the wrong sort of person for design layout. Better tools and more understanding may instead of endangering designers, may create a new evolved breed of designer that can satisfy the needs that the makers and next generation embedded systems will require.
It seems to me that there are far fewer independent PCB designers than there were 15-20 years ago. Some of them grouped together and morphed into turnkey operations offering PCB layout, PCB manufacture (or organizing PCB manufacture), prototype assembly, mechanical design and production assembly.
Of course there are good and bad PCB designers, but one of the problems we have faced frequently is CAD compatibilty with our own, so that we can maintain the design. Thde only time we had any success (and we have tried most of the above approaches) is when we absorbed the PCB Designer into our organization.
Looking at job adverts, it seems to me that autorouting and multilayers have allowed engineers to encroach on PCB design. I suppose this is part of the enterpreneur environment where resources are at a premium and PCB optimization is not.
I have laid out many boards (I did write the blog Max referred to above), but I am nowhere near as good as the dedicated PCB designers I have worked with. I also feel that my time is better spent elsewhere.
I think that the requirements for PCB designers have changed, and I do hope (for my sake if not theirs) that the profession can adapt.
@Antedeluvian: I think that the requirements for PCB designers have changed, and I do hope (for my sake if not theirs) that the profession can adapt.
I agree -- for the simpler boards it may still be the case that layout designers can get by treating the components as black boxes -- but as designs increase in complexity they have to become much more knowledgable about the components and the underlying electrical aspects of everything.
I have done a lot of my own layouts, starting with tape many years ago and using many different CAD programs. I have also had layout specialists reporting to me and used independent consultants for layout.
It has been my observation that the best PCB designers are really artists. They see thing I can't like the best placement and ways to route that last difficult trace. Generally they don't know the critical points of a design such as high speed, high voltage, high current or noise sensitive parts of the circuit. The design engineer needs to work closely with the board designer on these areas. In many cases I have sat next to the PCB designer as he did these areas.
Another area the dedicated PCB designer has an advantage is the knowledge of the tools. They will have skills that those of us who do a board every 4-5 months don't. I keep a cheat sheet of tricks so I don't have to figure them out every time, but that is only a stop gap. A dedicated PCB designer will be able to crank out a board much quicker than I can.
There are times when the circuit designer doing the layout is fine, and times when a dedicated layout person will be faster and better.
Just the physical arrangement ( "layout" ) of wiring on PCBs ( to minimize lengths, bends, stubs, separation of signal from PWR / GND, the no. of layers etc. ) was adequate at lower speeds, but not any more. As the speed of inter-chip communication through the wiring on PCBs rise, the electrical performance ( propagation delay, SSN, RF, SI , ,.. ) of those wiring on PCBs become ever more critical. For wiring ( interconnect ) at the die level ( between transistors, between functional blocks ) CAD has been dominant for many nodes now, the same happened to fine - pitch PCBs ( organic Substrates ) about 15 years ago and is now true for high - end PCBs too. People who do these things are changing accordingly.
@Max: As you have mentioned: "...Another reason is that layout designers are starting to retire, and not many young folks are stepping forward to take their place..."
I agree with what you have said. Many layout engineers are retiring or about to retire but not many young engineers are showing interest to enter this field. As the designs are getting complex and compact, shall we get enough skilled layout engineers in future? Not sure. But will the design engineers would like to do that job? I am pretty sure not many would be interested, if given a choice.
Being a design engineer I have a great admiration of my layout designer friends as I consider thia job requiring lots of patience and yet repeating in nature...not very rewarding. PCB design is not fun unless I am making something for myself (I love designing my own board if I have time and making it for myself) and not while working for others. For a complex 12 layer (or more), I am sure the design engineer would require a layout engineer to work with him/her as there would be a lots of time spent and dedication needed on that layout, which the design engineer can't afford to spend that time/efforts. Hence the demand of layout engineers would remain almost the same.
But the question is, shall there be skilled layout designers left out after a decade? An interesting trend I could see is that layout engineers are getting themselves trained in EMI/EMC, Signal Integrity and other design fundamentals so that they are capable of understanding the design criticalities. This helps them to have a knowledge of what they are doing and sometimes they are mentoring the new younger engineers too about the possible challenges in the design and providing solution; they are also actively participating in the design & review discussions...a possible motivating factors?
This article actually does a good job of presenting WHY we are endangered! The article focuses on PCB design tools, and connecting the dots. That is the same focus for the people who make the personnel decisions: Design Engineers are smart people, they can learn tools. Tools are getting smarter, they can replace experience. Anyone can connect dots.
The tools are the easiest part of my job. Almost anyone can learn enough to connect dots rather quickly. Of course, a dedicated PCB designer will know the tool in depth and will be more efficient.
Sure, anyone CAN connect dots. Of course, a dedicated PCB designer with more experience will be more efficient.
But without the dedicated PCB designer, the product manager will still get a PCB into his product. With one less salary to pay. He may not know the board took longer to design and is more expensive to produce, He does not know that there were 2 extra design cycles to address concerns from the fabricator and assembler, that might have been avoided. This is how it's been done, this is how much a board costs.
If he never sees the results of a board designed with a thorough knowledge of EMI. SI, DFM, DFT, etc., with the long term cost savings that exceed the extra salary, he will ever see the need to hire a PCB designer.
That's how a species becomes extinct. If he never hires a PCB designer, he will never learn why he needs one. As less PCB designers are hired in more companies, there is less justification for us. Soon, no one sees the value.
Fewer companies are hiring PCB designers, so it's not a field a lot of young people will see as a career choice. Which means that even the companies that currently have good PCB designers, and see that value, can't hire a good PCB designer to replace the one that just retired.
Thus, the evolutionary cycle continues. But in this case, it's extinction of the fittest. Will PCBs still exist long after I have waded into the tar pit? Of course. They will just be far less efficient. And no one will know.
I did learn my trade in college, not a trade school, back in the day. Hand taping with a xacto knife.
About engineers, can not see them designing a board in a reasonable amount of time or to manufacturing guidelines. Have tried to complete designs started by engineers, have had to start with a new database and go from there.
Firstly, when I hear 'connect the dots', then I know the topic of discussion is NOT PCB Layout Designers. That mentality can only refer to someone who is NOT a designer. You might as well just use an autorouter if you think that way. A good PCB Layout Designer actually DESIGNS the board, and in the process applies device and technology rules, fabrication rules, assembly rules and, due the the fact that we ARE ageing, a lot of experience. Actually making the connections is not an issue, never really has been if you understand the design process properly. Routing the traces is simply a process, albeit time consuming, but it should not be excessively difficult. It is really just the process of placing copper connections where you ALREADY know they will go. The real design aspect of any PCB design is PLACEMENT and adherence to fab and assembly rules for manufacturability. If the design is correctly placed then the fanout and route process should not be, and rarely is, a difficult task, it is simply a time consuming process.
Now there is a suggestion that the toolsets are becoming more engineer friendly. Well, I have had to do designs where engineers have been heavily involved in the placement stage, some even want to do the detail placement around the chips, some even try to do the 'critical' routes!. I have never yet seen a usable database come from an engineer. I usually end up telling them that it actually increases the cost and time to do the board because I first need to remove everything they did so I can start clean and do it properly.
Tools should evove to make usage more efficient for any user, not 'for engineers'. I have used at least 6 different CAD tools over a 30 year period and have seen a significant evolution in the tools. Some have evolved considerably while others are essentially the same as they were 10 years ago, with window dressing added. The main tool I use now is about to recieve a significant update and from what I have already seen, it is a huge step forward in usability, this is the progress we need. Good quality tools are expensive though, and we need to recognize and expect this. There are not as many PCB designers as there are word processors, and the tools are a lot more complex. We should expect that they are expensive, it costs money to produce quality software and to keep improving it. the tools we have available for just a few thousand dollars are NOT suitable for today's and tomorrow's highly complex tasks, they might like to say they are, but if you use them you will soon see beyond the window dressing and be left wanting better tools.
An engineer typically has little or no regard for fabrication and assembly rules, and nor should they. This is not their concern, they need to engineer the design and work closely with someone who does fully understand the physical implementation part of the process, the PCB Designer.
The problem is, where are the next generation of true PCB designers coming from? There is little or no training for such. We all recognise that this task is becoming more and more technical and engineering oriented. PCB designers do need to have a good understanding of electronics and circuit theory, but they do not need to be degreed engineers, there are many other courses that can provide the knowledge required, diploma level courses are certainly plenty. The main knowledge, as with engineering itself, comes from experience of practical problem solving situations, on the job. It takes a minimum of five years to become even a capable PCB designer, and you don't get to be a qualified senior designer till much longer than that. I have believed for a while now that the 'pcb design' portion, often an 'elective' of engineering and diploma courses, should actually be a subject in it's own right and be set up as a minimum one year unit in these courses. This should require the student to undertake all CAD library development for a complex design, all schematic entry, mechanical definition, stackup design, rules entry, placement, routing, power and ground planes design, rules checking and verification and all manufacturing output generation for a serious complex design. Instead, what I have seen in the past is a two or four week, 3 to 5 hours a week, 'PCB design topic' in these courses. The lowest cost or even free tools are often used, a 'nothing' design is usually done, pre prepared libraries are used, placement is trivial because the design is so non critical, and auto routers are used for the routing. No fab or assembly rules are considered, and usually no electrical constraints are considered because the trivial 'canned' design they do does not require them. And we wonder why we do not see any PCB designers coming in to the industry !!.
It's high time we recognize that PCB design IS a career path and a very valuable and important one at that. If vendors want more exposure and more people using their tools, then they need to make these tools available to educational institutions at no cost, and full design suites at that - not cut down versions. Courses need to be written that would provide a minimum of one, preferrably two years of real training for young people who could then go on and become useful designers in this evovling industry.
The question should not be 'Are PCB Designers becoming obsolete', it should be 'Why are we not, and how can we be, producing new young high quality PCB designers'.
There is definitely a place for engineers in the PCB design process, and will be more and more so as technology becomes faster and faster, but there will always be, in my opinion, an equally important place for a good PCB Designer to work alongside those engineers.
@bpoda: Firstly, when I hear 'connect the dots', then I know the topic of discussion is NOT PCB Layout Designers.
I think the person who used the term "connect the dots" is actually on your side -- he/she said "Sure, anyone CAN connect dots...." but then went on to say that PCB layoud designers do far more than that.
Agree with you. And I have had similar experience.
Except for one item: I do believe the EE SHOULD know production materials, processes and manufacturing practices as much as he knows circuit design, components available and math. Even if they don't do pcb layout work.
Reason: They will never know what is possible to build .. until they have a passing knowledge of all the elements involved. They certainly will need to be able to accurately assess risks involved with any "state of the art" projects being considered... it is part of their job.
If the engineer is stuck working older tech.. yea , sure , he can get away with limiting his knowledge base. I don't think this is a good career path.
For the same reason, I recommend PCB designers to continue their education on materials and processes (and their costs!) used in production... so they continue to add knowledgeable insight in their work and in working with others.
I completely agree with this post. I'm a 30 years-old Electrical engineer working as PCB designer for 5 years now. I've never met or worked with a designer as young as me. With all the respect, most of my coworkers has been much older than me.
This is no a problem in itself but It's a sign that the PCB industry needs a fresh air. (A lot!)
The workflow, some CADs and mainly the accessibility of the knowledge are old-fashioned.
Some companies are doing really well trying to create a PCB Industry 2.0 (let me use this).
Altium are improving the usability of their CAD (Remember, usability = productivity). Have you checked the Altium documentation? At last, a clear and useful documentation. And the interface is just clean. It just works like the PCB Designer expects. Hats off.
New communities like Arduino or Raspberry Pi are creating good environments for learning and sharing knowledge. A lot of newbies (coming from software environments) asking how to create their first PCB for extending the functionality of these platforms.
But what I consider the most important is the accessibility to the knowledge.
How is possible that the IPC standtard IPC 2222 cost 114 dollars?? I just ridiculous! The most basic and important standard for a PCB Design costs 114 dollars. Are the IPC trying to standardise the industry or just make money? I bet the second.
In humble my opinion these basics standards should be accessible for everyone (yes, free). This would create a more mature industry and allow to create better designs and PCBs.
What about the courses? 1000 pounds for one day course about basic PCB design. I just finished a 8 weeks free online course about Python in Coursera. How many course about PCB design in Coursera? Zero.
The more accessible is the knowledge the more engineers will go into the PCB Design Industry.
I too started out in the days of acetate and tape, and I remember when we got our first PCB CAD system - but dedicated PCB designers did the work under the guidance of the design EE. It's been quite a number of years since I've worked in a company that had actual PCB designers, and I think that's wrong.
CAD companies have for years promoted their software on the basis that one person can do schematic capture and pcb layout in one integrated tool, and companies have bought into this as a way to save headcount. Design engineers now have to spend time laying out boards instead of creating innovative new circuit designs and this is not an efficient way to run a product development group.
I'm not implying that PCB design isn't creative in it's own way, and a talented pcb designer is worth his weight in gold, but as a manager I want my EEs designing circuits for new products, not spending time laying out a board.
Having one person design the circuits then lay out the board is inefficent, and it's a myth promulgated by the CAD software companies.
Years ago, when I worked at In Focus, we had a layout guy: Tom. I don't remember his last name.
He was a wizard. With one hand, he could be punching key codes so fast I could barely follow him, with the other hand, moving the mouse around like crazy, all while talking to me.
These days, it's pretty common for engineers I deal with to have lost that resource. The layout specialist is gone and the design engineer has to do the job. In general, I would say that they don't like it, nor have they all been trained on what makes a good, manufacturable, PC board.
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