Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

[Dan Mills]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

The trick is to hire electronics engineers who can do layout, not pcb cad operators (Unless they are Marce).

Any electronics engineer can pick up a cad system in reasonable time (certainly well enough to edit libs and do simple layout), and will probably already have a bone deep understanding that current flows in loops and that loop area is generally a bad thing in switching circuits (The essence of layout for switchers and RF both).

I work in a small team of five engineers, and any one of us can walk up to pretty much any cad system and figure the thing out, Dxd/Pads, Altium, Orcad, Eagle, DesignSpark!! Got projects in all of them for one reason or another, and I did not think that being expected to figure out the basics of a new package in less then a week was anything special (Not get quick at it, that takes years, but basic libraries and footprint editing, placing parts and hooking them up), I don't think we have any Cadstar projects, but if we do it will just be another tool to figure out.

We are not SMPSU specialists, but again we have all laid the things out, and apart from a recent embarrassment (a very mundane 5V 3A buck where the app note circuit did NOT work as expected), our layouts usually get the job done.

Altium has this fearsome reputation which is pretty much undeserved, it is actually by far the easiest of the big packages in my view (For pain, try doing anything much in Dxd/Pads), the Altium web based help is really quite good (Unlike Mentors effort), and once you figure out the one hand on the keyboard, one hand on the mouse thing (And that pretty much every command string can be discovered from exploring the menus) it is actually really quick.

Regards, Dan.

 

[treez]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

Well, you sound to me like you are of exceptional talent, a minority in that respect, from your description it sounds to me like you work for one of those consultancies in the Cambridge Science Park or something. That RF company in northern UK would like to employ yourself or someone of your skill set, but as you can imagine, there just aren't people like yourself around.

If you make anything ridiculously overly difficult, there will always be those minority of people than can still do it, and of course, having pals who have sussed it out and can help out always helps.
Of course, a lot of consultancies love the fact that the majority cant suss out PCB CAD packages, because it just means that the labour market is less competitive…the downside of this is that Tax revenue to the country goes down. That doesn’t matter to UK at the minute, as it has loads of north sea oil, but very soon that will be gone.

And by the way, I watched a PhD Electronics guy struggle to lay out a simple lighting test board at one place..after three days he managed nothing, and had to ask for help from the PCB CAD operator guy (who , incidentally, used to be a SMD machine operator)….it just shows that its often just a case of being “in the know”

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One point is that if you are a contractor, and somebody hires you to go into their company and do an SMPS for them, they usually expect you to do it in there own high end CAD package, and wont let you use eagle.
These Engineering Managers always expect you to be able to use their CAD package within a day at the most……all the general staff of the company expect that aswell…because everybody believes that all PCB CAD packages are just simple etch-a-sketch drawing tools….and when you as a smps design contractor are still struggling with their CAD package after a day….they get mad and assume that the contractor is thick, indeed, too thick to be able to design an SMPS…and so often one gets sacked.
…I suppose consultancies kind of like the existence of this problem, because when the contractor gets sacked because he/she couldn’t operate the PCB CAD package, the company usually goes to a consultancy and pays the consultancy to do the job instead…the consultancies often have acquaintances who are CAD package Apps guys and can help them with PCB CAD issues where necessary.
…The consultancies, being “in the know” about the PCB CAD package, of course, assure the company that they did the right thing in sacking the “dumb contractor who couldn’t even operate a PCB CAD package after a day”……

 

[marce]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

I disagree with the view that engineers make for good layout, they don't... had to correct quite a few. These days you need a dedicated layout engineer there are a lot of us about, it is about education and training and realising that PCB layout is a complex process, that requires a special skill set and not just a job anyone can do.
Again regarding SMPS's I cannot believe there is all this grief about a simple power supply layout, the controllers have a data sheet with layout guides... all the main IC manufacturers have design guides on SMPS layout from the historic AN-1149 to hundred of others covering all aspects of the layout and any possible issues such as EMC... Like high speed layout and learning how currents flow it just requires some education, which if you are doing layout then you have to learn (or come and work with me a few months and you will learn.....) it is a requirement of the skill set for a PCB designer these days...
Me I am reaping the benefits of many years of studying PCB design (30+) as I get to work on many cutting edge designs, always in work and get headhunted a couple of times a year so the effort has been worth it, so get learning and stop moaning. Companies will train someone with the right skill set on a new CAD system, it is the PCB design skills that they are after:grin:


How fast to electrons travel when moving as an electrical current through copper track on a PCB.... (this is not the same as electron orbit in an atom).

 

[treez]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

How fast do electrons travel when moving as an electrical current through copper track on a PCB.... (this is not the same as electron orbit in an atom).

..ive had this one before, strictly speaking the energy actually travels as EM waves and its not electron flow at all, but at low frequency you can kind of get away with the electron flow analogy….as you know, its actually all governed by Maxwell’s equations. The “low frequency approximation” is one of the biggest lies in electronics today….but who cares if you can get washing machines and stuff working by using it.

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Anyway, the Germans are the best at Engineering and Eagle is the most common PCB package in Germany wherever the PCBs are non-DDR3 type PCBs.
I think that says it all….the Germans are the best team-workers of Engineering…..If a German Engineer or German Engineering company sees a way by which he/she alone can make it rich, they will not care, the Germans are more interested in helping their fellows around them…this is why they acknowledge that Eagle is best as said above.
In Germany, they probably have good, proper simplified guides to using high-end PCB packages which they widely share amongst each other…..this just doesn’t happen in UK….we keep our secrets to ourselves or our closest clique….this is why the Germans are better than UK at engineering.

PCB layout staff in UK are that bad at laying out smps that I have to give them my guide to laying out SMPS, which I attach here, I gladly share it with all..even after giving this document, most layouters still get smps layout totally wrong.

 

[Dan Mills]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

Mean electron drift velocity in a metallic conductor is tiny at any reasonable current, think in terms of millimetres per second, this is basic A level physics (Note this is not the case in a vacuum tube because there are far fewer available charge carriers, also the velocity changes across the tube because the mean free path is long compared to the geometry) .

I think I have a new interview question......

Actually, just like everything else, layout folk are of variable levels of expertise, there are people like Marce who I would defer to in a heartbeat when the going gets tough, but well, you do not always discover genius (In the UK or Germany, or anywhere else).

And no switchers are not really that hard layout wise, so I don't know where your employer is finding layout staff, but they are somehow hiring from the 'hard of thinking' end of the market.

I understanding basic EM behaviour and its implications is just as much a part of the job as knowing the applicable IPC standards.

Regards, Dan.

 

[marce]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

I use the electron drift velocity and also ask them to describe a SMPS in one sentence in terms of layout... I also ask about 90 deg corners and what defines a high speed signal.

There are lots of good layout guys in the UK, though they are getting old...
Actually you may find that Cadence, Mentor and Zuken (and now Altium) outsell Eagle.
We don't keep things to our selves, that is why I come on here and occasionally other forums... to give people the benefit of my (often acerbic) limited knowledge because I do truly believe that PCB design should be treated as a proper engineering discipline (and have done for many years) and not just a job that anyone can do.....
But then as some at work think I am rather sad, as I will often read papers or books on PCB related stuff on a weekend!
Oh and all subscribe to:
https://www.pcdandf.com/pcdesign/
as well a PCB 007 and a couple of other mags.
Also do the CID courses, its a good start and shows you are dedicated to learning the skills required for PCB design, and look at the IPC stuff.
And in my case probably get a life

 

[treez]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

ask them to describe a SMPS in one sentence in terms of layout

I suppose "manage the high di/dt current loops" is the one sentence.
What you often find (and this is from being at 25 different uk electronics co's), is that the PCB CAD guys are wonderful at finding and implementing any feature of the CAD, but haven't got a clue about high di/dt current loops of an smps, and then , especially if the engineering manager is non-tech type, they get the eng'g managers support to get your layout rules of smps sent to the bin.....and one finds oneself being told that layout problems don't apply to smps as they have too low switching frequency....
This is why eagle pcb program is so desperately needed, -because it allows the engineer who knows about the smps high di/dt loops to actually do the layout themselves. Without having to rely on the CAD wizards who don’t even appreciate that there is changing current in smps’s

 

[marce]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

Sorry but I disagree, eagle is not widely used the others I mentioned before are. I would love to know which 25 firms you are referring to because I have a totally different view of the state of PCB design in the UK. You make it sound like it is all a mickey mouse set up, I find this worrying. 25 is a lot of firms to work at, I don't even manage that with my bureau work and have only worked at six full time in 30 years..... I also think that you are decrying UK PCB designers, I would hope at least some of them understand that currents flow round a PCB:shock:

 

[treez]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

They understand there are currents, but not to the detail as per my (simple) doc of post#24, which , as I believe you agree, is necessary knowledge for anyone laying out an smps.
You say you have worked in 6 UK co's.......I can tell you that at least six of my previous co's/departments do not now even exist!! (eg link below)
Eagle is the most commonly used PCB package in Germany and China, where simple PCBs are being layed out (Not DDR3 type)

https://www.edaboard.com/threads/349806/

 

[Dan Mills]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

Yea, treez seems to have found a whole load of clowns to work for (and with), treez you might want to look at the gigs you are accepting.

This does not at all match with my experience, hell I know plenty of amateurs who are quite capable of laying out a switcher so it works right, it is NOT rocket science.

There is a real win in using the same toolchain for the micky mouse boards as is used for the complex stuff, it means that some poor sod in five years trying to change a footprint to deal with a component obsolescence can use the same tool they have been using for years, and that half hour job is a half hour job not three days of swearing at ponycad, maintenance of old designs is made much harder then it needs to be by contractors not using the company standard tools.

I see no reason whatsoever why a smpsu designer (for whom layout does matter) should not learn the common tools of the layout trade at least well enough, same with things like FEM solvers for thermal and EM simulation and a bit of mechanical cad, these are just things you need to pick up to be a reasonably well rounded electronics engineer IMHO.

Don't moan about how hard the standard tools are, just learn them (The nice thing about learning new skills is that you do it once then have it available), besides listing Pads/Dxd/Altium/Cadence whatever on your CV is worth real money even if you are not a layout specialist.

Regards, Dan.

 

[treez]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

Hello,
No doubt then , that all would agree to the following test to see if high end PCB layout programs really are hard or easy……
In order to see if High end PCB Layout programs are not more difficult than they should be, a test should be done as follows….

Thirty electronics graduates should be chosen at random, none of whom should have any prior experience of using a high end PCB layout program…

They should each be given the task (over 8 hours in a day) of making a 2cm by 2cm PCB (1.6mm thick) comprising nothing more than a 0805 resistor and 0603 capacitor connected in parallel on the top layer. The bottom layer should be completely covered in copper, to within 1mm of the edge of the PCB and should be connected by three vias (round, 0.6mm hole diameter, 1.2mm total diameter) to the net of one terminal of the resistor/capacitor. The components should be named “R1” and “C1” in silkscreen.
There should be solder resist correctly covering the top layer, except for over the solder mask, which would be outside 0.2mm outside the copper of the resistor/capacitor pads.
There should be a solder paste layer, covering each pad of the R and C to within 0.2mm of the pad’s edges.
A rectangular silkscreen “box” of 0.3mm line thickness should surround each component. Any silkscreen should never be nearer than 0.3mm to a pad.
Different net copper should be at least 0.3mm apart.
No part of any pad should be nearer than 1mm to a via hole.
Via holes should be at least 1mm apart.
No hole should be nearer than 1mm from the board edge.
Each of the components should be correctly placed into a library named “TEST”. The components should have their centres correctly centred so that a file of pick-n-place coordinates can be delivered to the PCB assemblers.
There should be no solder resist on the bottom layer.

After finishing the PCB, the gerber files should be correctly produced, to include layers as follows…top copper, bottom copper, silkscreen, solder mask, solder paste.

The trial people will each be given a pre-made version of this PCB , so they have a better idea of what it is they are meant to do.

Let’s get this test done with a high end PCB layout program, and lets see just how easy these high end PCB layout programs are not!

The result of all this, will be that the Government works out what a shambles the high end PCB layout fraternity is, and realises that this is holding up the country’s industry, meaning a reduction in tax revenue due to lower productivity….then the government will sort it out…By either askin for proper “simplified guides” to be made, or a new PCB layout program made, or rather, just stick with Eagle for simple boards, and make an augmented Eagle for the DDR3 type boards.

A PCB is a simple structure, there is no earthly reason why laying out a simple PCB in a high end PCB layout program should be difficult.

If laying out a simple PCB in Eagle is simple (which it is), then why is this not simple to do in a high end PCB layout program?

(by the way, the above trialees should have internet access throughout the 8 hours)

 

[NIKHILRAJ]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

why to blame "higher end PCB design tools?" . Only thing you can blame is that they charge huge money for their packages.
In my career beginning , I was doing board in Layout plus from Orcad and believed it is the best tool in the world. Later I found many other tools like allegro makes PCB Designers life much simpler.... Definitely it was so hard for me to switch to a new tool from Layout plus, It really took a considerable effort to learn the new tool... but going back to the old tool ... hmmm ... I am sorry ...
recently I got a chance to experience Kikad ( a decent free PCB design software) , but it took almost double time to finish the task than the' higher end PCB design tool'

 

[treez]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

Definitely it was so hard for me to switch to a new tool from Layout plus, It really took a considerable effort to learn the new tool

Thanks.
I know that you are a very competent person.
You chose to do engineering so you are a decent guy, prepared to work for your pay, a doer, a tryer.
But look at what you have said, it echos what so many others say…..you are expressing how very difficult for you it was to learn the high end tools.

It should be obvious to all of us that most PCBs are simple, its bits of copper stuck to a bit of fibreglass, with bits of solder resist etc……..there is no earthly reason that any PCB CAD Package should be difficult. These tools are made more difficult than they need to be.

Someone said to me that high-end PCB packages MUST be difficult because they can do all sorts of things…….well that doesn’t make sense…..my laptop can do fantastically complicated calculations, but its still easy to use it to do 2+2 in the provided windows calculator.

The "TEST" of the post#31 above is coming soon, someone from a big UK newspaper has contacted me through someone else, and they want to go ahead with it...they have the headline ready for the newspaper for after the test......"UK electronics graduates cannot make simple circuit board".
By the way, it is not myself that is driving this PCB “TEST” of post#31, I am just a go-between here. It is so widely known and acknowledged that the PCB layout fraternity needs shaking up, that this is what is now happening.

 

[Dan Mills]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

There is space for Photoshop as well as Microsoft paint, Audacity is simpler to use then Protools, Notepad is simpler then Emacs, Quickbooks is simpler then Sage, none of these things make either package poor necessarily (One could reasonably argue about notepad!), but simply aimed at different users!

If you are hired as an accountant and the company is a Sage shop, you will be expected to learn Sage, even if you feel you could do what you need to more quickly in Quickbooks that you use at home, no big deal it is just a tool.

I remember learning Altium (I was coming from Eagle V5 as I recall), it has an excellent quick start guide and they make a lot of pretty much step by step documentation available, it should not be a problem to pick up enough to (slowly) lay out a simple two layer board in a day or two (Mentors documentation can be 'interesting' I will grant you).

You seem to be arguing that you should not need to know the tools you will need to be productive in a given company when hired in a contracting role, but the whole point of hiring a contractor is that they can hit the ground running and that you do not have to train them, knowing the cad tool a given company uses is as much a requirement as being able to squeeze out a flyback design.

Productive is about far more being able to draw a schematic, it is about leaving a design that the company can take forward, and that only happens if it meets house standards and is done in house standard tools.

Most graduates are basically useless for anything except making coffee for at least six months after you hire them, and this is universal, NOT just an engineering thing, I would not be turning them loose on a real board without CLOSE supervision and review until they had gotten some experience.

BTW: We are about to make the switch from PADS to Altium, for all sorts or reasons, productivity being well up the list, as is integration with our new ERP system. Eagle was not even in the running (And quite a lot of what we do is low speed power boards), nobody here seems overly worried by it (And I am the only existing Altium user here).

Regards, Dan.

 

[treez]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

You seem to be arguing that you should not need to know the tools you will need to be productive in a given company when hired in a contracting role

..not at all, I was given two days to get a job done, tried my best, but in fact after one day, they didn't think id achieved enough and sacked me..i didn't say that I refused to learn anything.

The point is that a PCB is a bit of fibreglass with some copper on it, plus some other stuff. It shouldn’t be anywhere near as difficult as it is.
Tax revenues are suffering as a result.
I’ve already discussed why those who have already learned these tools by buddying up with those “in the know”, or by having the great skills of a computer hacker, wont be interested in helping newbys come onto the high-end PCB package bandwagon like I describe.

The fact that you are trying to deflect this off to packages like "notepad" & "paint" shows that, with all the greatest of respect, you are not taking this seriously, though your other opinions are well appreciated, and thankyou for them.

 

[Dan Mills]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

Thing is I don't see it, rework is fundamentally boring, so I would much rather have the newbies on the good stuff because it would mean that I have to do much less rework and could spend my time going sailing instead.

Quickbooks Vs Sage is pretty much equivalent to Eagle Vs Altium in both the complexity and functionality differences, Paint Vs Photoshop is about the same.

If you take the overly broad view then **ANYTHING** is simple,
a PCB as a laminate is simple if viewed from that perspective (As long as you don't look too close, copper surface finish matters once the frequency gets high enough, as does things like substrate weave).
However if seen from a schematic perspective it is less so, and if seen from a manufacturability, reliability or a 3D electromagnetic perspective less so again, now add in BOM management procurement, mechanical integration, thermal modelling, impedance control (and its interaction with the component tolerances)....

The simple tools usually deal with putting footprints and copper on Gerbers just fine, but that is about 20% or what a major tool does when integrated with a companies workflow, and automating that other 80% of the job is so worth it.

It is of course possible for a company to pick completely the wrong tool for the scale of boards they are doing, but they need to be picking the tool for the most complex stuff they expect to do, not the least (And power supplies are seldom the most complex thing they expect to do).

End of the day, tools that are designed to be used day in, day out are different to ones designed for the casual user for a reason that has nothing to do with being aimed at some sort of fictitious elite users who run with the Chaos Computer Club. It has everything to do with the fact that a steep learning curve taking you to a higher level of productivity eventually pays for itself really quickly when design is what you do every day.

Regards, Dan.

 

[treez]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

One question has still not been answered…."Why is a simple PCB easy to lay out in Eagle, but very difficult to lay out in a high-end PCB package?" ....applying to peoples who have never previously used PCB cad packages.

The point is also that Engineering Managers and such , do not have time to learn these high-end packages, but, they MUST be able to go into one and check for example the library parts etc…….i cant see any engineering manager being able to open up a high-end pcb package and be able to inspect it, -they would quickly get lost….they cannot ask the cad operator to do it for them, because the cad guy might hide the “bad bits”…the engineering manager needs to inspect by themselves.

 

[treez]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

OK Anybody out there, what about a challenge, ..how much money would you want, to write a document and youtube video which allows ANY person with basic knowledge of electronics components and basic knowledge of the actual structure of a PCB, to be able to complete the task of the first post#31 (in Altium). By this I mean for people who have never touched any PCB layout package before. How much would you want for that?....your notes and video must allow the completion of the task without them needing to refer to anything else other than your documents/video.
(ok granted they would have to look at the datasheet for the resistor and cap)
Also, if you think such documentation cannot possibly be written by anyone, then please state that.
The money could be yours.

(It is granted that the people who you will be writing these notes for will know how to use a windows based computer.)

 

[FlapJack]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

One question has still not been answered…."Why is a simple PCB easy to lay out in Eagle, but very difficult to lay out in a high-end PCB package?"

What can you tell a man with two black eyes. Nothing, he has already been told twice.

 

[treez]

Re: Why are simple PCBs difficult to lay out in "High-end" PCB layout packages?

OK please allow me to explain, I am part of a workgroup who is tasked to investigate this on behalf of a wealthy client. This wealthy client was first approached by a well-known politician.
This all started some 5 years ago, when a company in Yorkshire, UK wanted to get somebody to do a 10W LED driver PCB in their high-end PCB package. Their own PCB guy was busy and couldn’t do it in the short timeframe.
So an external PCB package guy was called in to do it. He charged £3700 for two days work. They couldn’t find anybody else available to do it. This ended up getting mentioned to the local politician, who told the other politician.
They investigated and found that a great many UK companies were paying high-end PCB package contractors wages of typically in the region of £40/hr…and in vast numbers of cases these are long term contracts.
It was deemed that the shortage of staff that was leading to these exorbitant rates was due to the fact that the high-end PCB packages , for various reasons, are made harder than they need to be…and here we are now.
(Incidentally, I actually sat with the CAD guy who did the 10W LED driver board, because I had to tell him how to lay out the switch mode high di/dt current loops. I sat with him for five hours, and after that we had the most of the board placed and routing mostly done. The CAD guy then spent the next day by himself tidying it up and gerbering it. The CAD guy hadn’t made the library parts, -he used library parts made by myself…apart from the QFN type FET, for which he made the footprint. –Incidentally, he did the QFN type footprint wrong, and I ended up getting a call from the PCB manufacturer saying “you don’t really mean that QFN footprint to be like that do you?”)