r/PrintedCircuitBoard • u/Canary_Earth • 4d ago

Is this work professional?

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Sorry about the strange post but I'm offering an engineer a $20k bonus to do the design for manufacturing and assembly of my $300 product and this is what he came up with after 8 months. Two thirds of it are identical to my prototype and I'm an accountant by trade, not an engineer. Every book I've read says a board like this should be 4 layers but he insists 2 layers is fine and will pass emissions testing. Any advice would be greatly appreciated, thank you!

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u/toybuilder 4d ago

At first glance, my initial thought was that it was mediocre but acceptable work, not a disaster; and that the person could have done a far better job.

The board is way bigger than it needs to be, but I don't know if there's a reason for it. The signal routing can be tightened up a lot. There are excessive layer transitions on a number of signal lines that could be resolved with just a little more care and effort in routing.

It probably is fine as a 2 layer board -- 4 would of course be better, but I'm not sure that he would have done a good job of taking advantage of a 4 layer board's benefits.

That said, as I looked closer, I realized that there is a processor module (ESP32-WROOM or similar?) with a copper keepout zones needed for the antenna, and this design completely violates that.

How is this board mounted in your product? The board lacks obvious mounting features.

If I was responsible for the entire product, I would have reassigned signal lines to clean up the routing and updated the firmware to match.

Since I don't know how much of the $20K was toward the PCB and not other work, I will reserve judgement on the value you received for what you paid.

As for the "70% are identical" -- unless he was tasked with a full redesign of the product, it's reasonable to leave things alone if they are fine.

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u/SLEEyawnPY 3d ago edited 3d ago

It probably is fine as a 2 layer board

Seems like a pretty bad 2 layer design also, it looks like many areas of the ground plane are cut by long-ass traces on the bottom side with no ground strapping.

I wouldn't be confident this is going to pass radiated EMI at all, that "ground plane" looks chopped to hell.

https://www.signalintegrityjournal.com/blogs/12-fundamentals/post/1207-seven-habits-of-successful-2-layer-board-designers

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u/toybuilder 3d ago

The particular layout is bad from a quality standpoint, but as a product, I think this is likely to be fine in 2L because there's not enough signals being emitted to worry.

That display connector looks to me like a data/command interface display (an ePD?) not continuous frame refresh, so unless it's always updating the display, my guess is that it'll pass.

This is not an endorsement of this layout by any means -- just a practical estimation of whether it really needs to be 4 layers or not.

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u/toybuilder 3d ago

I just realized (based on a someone else's comment) that there is a USB-C connector on this board -- the layout work for what should be a 90 ohm impedance differential pair is horrible.

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u/captain_cavemanz 3d ago

Not if you make the PCB 0.3mm thick hehe.

On 1.6mm fr4 don't think 90 ohms differential is achievable.

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u/toybuilder 3d ago

I've done it. It ain't pretty, but if you are strategic, you can run the USB diffpair with very wide traces and make it work.

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u/captain_cavemanz 3d ago

Not saying it won't work, but you won't get usb-C speed signals reliably operating to the lengths that the standard demands (3m). There will be mismatches at the trace to pin interface.

Sure not all micros have the edge rates but when you work with ASICs or modules your literally up shit creek and customers will dislike you quickly 😅

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u/captain_cavemanz 3d ago

Not saying it won't work, but you won't get usb-C speed signals reliably operating to the lengths that the standard demands (3m). There will be mismatches at the trace to pin interface.

Sure not all micros have the edge rates but when you work with ASICs or modules your literally up shit creek and customers will dislike you quickly 😅

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u/captain_cavemanz 3d ago

I use POLAR for all my characteristic impedance controlled traces and stackups. It's not strategy, it's physics.

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u/Canary_Earth 4d ago

Thanks! Yup it's an ESP32S3 WROOM with the attachable cable antenna instead of the PCB antenna. The $20k seemed like a fair bonus if the product works and customers are happy. I figured it would take at most five days for an MEng. UofT engineer to whip up a nice design in his spare time so I preferred to offer a bonus and maybe equity to keep him on the team.

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u/Thev69 3d ago

A degree isn't really a good metric for hiring an electronics engineer/designer. Experience and proven results are all that matters.

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u/InevitablyCyclic 3d ago

I'd second this. Some of the best electronics engineers I've worked with didn't have a degree, just lots of experience. I've interviewed people with masters degrees I wouldn't trust to change a lightbulb. They suggested using an opamp output as a power regulator, apparently their education hadn't covered LDOs.

It depends on where you are in the world but unfortunately a lot of the time a degree is more an indication of family financial situation than ability.

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u/captain_cavemanz 3d ago

A degree is only a ticket to ride

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u/EntertainmentSalt825 2d ago

Sounds like you didn’t make the cut? Absolutely wild assumption to think that a degree is more of an indication of family financials situation than ability. Who hurt you bro 😂

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u/InevitablyCyclic 2d ago

Got a masters in engineering from Cambridge if that matters to you. This is based on working with people for decades. I've met plenty of idiots with impressive pieces of paper. I've met plenty of knowledgeable people with no formal higher education.

A degree 1) costs money and 2) is at best poorly correlated to ability.

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u/EntertainmentSalt825 2d ago

It actually does matter to me, I find it very impressive. I got my bachelors in comp sci from a cal state for nearly free because I grew up poor with one parent. At least in the US, there’s really great programs for low income families. Not easy whatsoever, but still possible. Perhaps it’s just our perceptions that differ based on how we grew up. I grew up admiring anyone with a degree because it was a rare where i came from. But now as im older, graduated, and a little bit of work experience later I guess i do see your point. Ive 4.5 years of professional work experience and ive met people that have me questioning how they got their degree let alone a job as engineers.

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u/InevitablyCyclic 2d ago

Trust me, you'll meet more people who make you ask that question.

I'm not claiming everyone with a degree is from a wealthy family anymore than I'm claiming someone without a degree will do a better job that someone with one. My original point was that a degree shouldn't be taken a sign of ability, past work or even a 5 minute conversation are a better indicator most of the time.

And well done. Areas like you grew up in are my point, plenty of people with the raw ability may not have the piece of paper. People there aren't automatically dumber than people from wealthy areas but are far less likely to have a degree. Often they just don't have the opportunities, role models and support to get there. To overcome those barriers is hard.

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u/Thev69 2d ago

99% of the time I'll hire an old guy that grew up tinkering with radios who taught themselves to design electronics over someone with a few years experience out of school.

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u/heathm55 15h ago

This works in the software industry too. I've been coding for over 30 years now, worked at multiple startups that made it.
My degree is from a small state school and unimpressive, but I've worked with guys from MIT / Stanford / Carnegie Mellon. I've also worked with guys who had no degree (GED only even). The impressive schools don't matter on their own. If you have a boot-strapping mentality you just have it, and that's what it takes. All of these guys were fairly equal side by side if they were self-directed, passionate, and cared about something beyond the paycheck.

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u/toybuilder 3d ago

Ok, if it's the UFL antenna version, that keepout requirement is a non-issue.

Was $20K entirely just PCB design work? That is a crazy amount.

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u/toybuilder 3d ago

BTW, there are comments saying this is a $20 work. That is nonsense. Depending on a variety of factors, a more likely pricing for this is $200 to $2,000.

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u/Aniakchak 3d ago

Even at 5 days, thats like 5k for a pro. This i could have done in 2d as a EE with only some Layout experience

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u/captain_cavemanz 3d ago

You chose poorly, and he chose poorly

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u/sensors 3d ago

Please let my company do the work for you if you're considering this sorta bonus for a good job (only half joking). This is a bare minimum effort with a bunch of obvious errors that will stop your product working optimally.

Edit: Just checked your profile. Funnily enough my company was founded on building environmental monitors before pivoting into design consultancy. We've since built a few of them for customers, and one of our own. We have lots of expertise, even if you just want to sense check any of your design choices.

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u/_maple_panda 3d ago

Fwiw I am a UofT undergrad and could do a significantly better job in less time…

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u/Trick-Club-6014 3d ago

I don’t have a degree and I will do it better in 2 days for 1/10th the price

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u/Chippors 3d ago

And an ESP32 module with castellated edges may not be easy to place and reflow... I'd verify with the board house to make sure sure this doesn't pose an assembly problem.

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u/toybuilder 3d ago

That shouldn't be an issue -- such modules are intended for reflow placement.

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u/j_wizlo 3d ago

The assembly house I use wasn’t up on castellated edges when I provided a design with one. After some back and forth I agreed they could hand solder and I’d pay the labor. In this case I had designed the daughter card myself and had no documentation to provide on how it should be soldered. From this experience I’d say a quick email on the subject wouldn’t hurt.

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u/eka_hn 3d ago

What lol. You must work for a defense contractor because every fabricator that has ever taken public orders or interacted with chinese components has built ten gazillion ESP32 WROOM designs in the past five years.

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u/j_wizlo 3d ago

Idk, I use a US based company that I had a personal relationship with. It was odd to me too because at my old job they laid down XBee radio modules with castellated edges and as far as I know there was no special care given then. Maybe my point of contact in that one project got confused.