Author Topic: Isn't it strange that you can make better PCBs at home than factories make?  (Read 50114 times)

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Offline timb

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #275 on: December 31, 2016, 10:47:46 pm »
Happy new year to everybody in this thread too...! :-+

Your non-sequitur is dismissed outright!
Any sufficiently advanced technology is indistinguishable from magic; e.g., Cheez Whiz, Hot Dogs and RF.
 
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Offline mrpackethead

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #276 on: December 31, 2016, 11:09:31 pm »
Happy new year to everybody in this thread too...! :-+

Your non-sequitur is dismissed outright!

Your non-non-sequitur is accepted.
On a quest to find increasingly complicated ways to blink things
 

Online Alex Eisenhut

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #277 on: December 31, 2016, 11:13:08 pm »


Curvy enough?
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Offline mrpackethead

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #278 on: December 31, 2016, 11:42:17 pm »
On a quest to find increasingly complicated ways to blink things
 

Offline MaximRecoil

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #279 on: January 01, 2017, 01:35:12 am »
A good PCB manufacturer will manufacture a PCB to YOUR requirements/specs.

If you need thick copper weight (eg 4 oz) to improve current handling and connector reliability they can often do this for you. Presumably you can order PCBs with rivets if you like?

Or maybe you think those Samsung and LG TVs used 'homemade' PCBs to get them to feature strengthening rivets in their TVs?

A suitable PCB factory will make the board to your requirements. If you deliberately ask them to make a board that doesn't meet the requirements for strength/thermal/current rating or you send them crude drawings rather than fine resolution drawings for the artworks then who is at fault here?

This isn't about what they technically can do, it is about what they typically do. I've pointed this out before, more than once. Also, at home you can use 100% analog processes to make a PCB (which produces the smoothest possible angled lines and curves), which includes a real screen print. Name a PCB factory that will do it that way.

The Bezier curve argument is just as silly. You might as well argue that the PCB factory can't replicate an 'arty' PCB that shows your palm print dipped in liquid and slapped on a PCB complete with random splashes and various other arty anomalies. They can't replicate your etching anomalies either and reproduce the true 'art' of the homemade original. But who cares?

False. Traces drawn with bezier curves isn't some random, off-the-wall thing; many old PCBs had them. The same goes for rivets and a real screen print. Granted, the real screen print was usually 1-color, but multi-color screen printing is a natural extension of that.
 

Offline ovnr

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #280 on: January 01, 2017, 02:29:41 am »
I'm not entirely sure what's up with your fetish for bezier curves. Yes, old PCBs had them because old PCBs were hand-drawn. They didn't hand-draw the PCBs because it was better, but because it was what they had back then. Having perfectly smooth lines does not make the PCB better; if it did, the industry would have offered it years ago!

Rivets? Same deal. If they could've done plated vias back in the day, they would damn well have. And there are plenty of screen-printed PCBs today. And if I hear "multi-color prints" related to PCBs, I'm just going to think you're off your rocker.


I'm also not entirely sure how you can conclude that riveted vias are "better" - and contrary to your delusions, just stating so does not in fact make it a fact. Yes, they may have better mechanical strength, but they will be more prone to thermal cycling stress. They're also massively larger than plated vias, and utterly impractical to use in large quantities. In addition, you cannot place them underneath modern packages.

All I'm seeing is "Maybe better in an unlikely scenario, and worse in all other ways". Yet you conclude they're better, and that it is an incontrovertible fact.


Still waiting for that guide on the ignore list, btw.
 
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Offline helius

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #281 on: January 01, 2017, 02:53:29 am »
I don't think it's true that PCBs were ever designed with cubic curves (which by definition would require a computer to calculate their slope). They were drawn by hand on film, with ink. These freehand shapes are not "Bezier" at all. You might as well argue that ancient Babylonians were using "Bezier" to draw cuneiform :palm:
There do exist, today, PCB tools that use arcs intensively to make denser interconnections (Topor is an example). Arcs have always been a part of Gerber format, derived from its ancestor G-Code and CNC machines. In principle, cubic curves can be estimated to a high degree of accuracy with arcs. The problem is that Gerber is capable of stroked paths only, not filled paths, because it controls a photoplotter. A curved shape that uses fills is much harder to represent using stroked paths. You need to submit PCBs in IPC-2581, not Gerber, to produce such shapes.
 
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Offline djnz

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #282 on: January 01, 2017, 06:52:03 am »
I lack the skill and equipment to make PCBs of home of the same quality as many factories can. I suspect this is true for many others as well.
 

Offline bpiphany

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #283 on: January 01, 2017, 09:40:22 am »
The problem is that Gerber is capable of stroked paths only, not filled paths, because it controls a photoplotter. A curved shape that uses fills is much harder to represent using stroked paths. You need to submit PCBs in IPC-2581, not Gerber, to produce such shapes.

The region mode is the preferred way to do filled shapes, at least since RS-274X. I believe arcs are permitted within this mode as well. At least gerbv seem to handle them.

Code: [Select]
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%LPD*%
%ADD10C,1.000000*%
D10*

X100Y100D02
G75*
G02*
X200Y200I100J0D01*
G01*
X200Y100D01*
X100Y100D01*

G36*
X300Y100D02
G75*
G02*
X400Y200I100J0D01*
G01*
X400Y100D01*
X300Y100D01*
G37*

M02*
 
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Offline LukeW

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #284 on: January 11, 2017, 07:18:52 pm »
So, do those rivets come in 10 thou?

And are the rivets flat enough to be put under a QFN chip? Or even for BGA escape routing? Didn't think so.

How about blind and buried rivets in your 4-layer board? Didn't think so.

Hand drilling and riveting at home with 4/4 rules? Or heck, let's be generous and expect reliable 6/6 results.
 

Offline Howardlong

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #285 on: January 11, 2017, 11:45:06 pm »
So, do those rivets come in 10 thou?

And are the rivets flat enough to be put under a QFN chip? Or even for BGA escape routing? Didn't think so.

How about blind and buried rivets in your 4-layer board? Didn't think so.

Hand drilling and riveting at home with 4/4 rules? Or heck, let's be generous and expect reliable 6/6 results.

To save you the effort, I already answered this as an actual owner of the device buried deep in this thread.

https://www.eevblog.com/forum/eda/isn't-it-strange-that-you-can-make-better-pcbs-at-home-than-factories-make/msg1098139/#msg1098139

The rivets are OK but only for unit testing. The tool is an expensive, and large, paperweight. One that would keep a certain toupee aficionado's business paperwork under wraps for some years at any rate.
 

Offline dunkemhigh

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #286 on: January 13, 2017, 02:44:12 am »
This isn't about what they technically can do, it is about what they typically do.

But on the other hand you are saying it's not about what you (that is, you personally or 'you' any other home user) typically does but what you could do.

Surely, if it's what hobbyists could do it should also be what factories could do. Or if what factories do do then what hobbyists also actually do.
 

Offline slicendice

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #287 on: January 13, 2017, 08:05:24 am »
What factories typically DO DO is a lot better quality than what DIYers typically DO DO! It all comes down to what equipment you use. Surely a $100k device can perform better than any hand or a $1k tool.

If you own all the $100k tools needed for making a good PCB then you are not the typical DIYer, you are the factory/PCB manufacturer.
 

Offline CatalinaWOW

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Re: Isn't it strange that you can make better PCBs at home than factories make?
« Reply #288 on: January 13, 2017, 06:21:41 pm »

False. Traces drawn with bezier curves isn't some random, off-the-wall thing; many old PCBs had them. The same goes for rivets and a real screen print. Granted, the real screen print was usually 1-color, but multi-color screen printing is a natural extension of that.

I would love to see your evidence that any old PCB was drawn with a Bezier curve.  I agree that many old PCBs had curved traces.   Often with varying width.  But they were generated by hand, not mathematics.  I know.  I did some, and watched many others.  Tools like Rubylith and cameras.  No computers involved.  I don't know when the first computer generated PCBs were done.  I know that my first contact with the technology was in the early 1970s and required large scale computing resources and expensive software that caused large corporations to think heavily before investing.  It was the 1980s before it became widespread.

I will agree that Beziers are an easy way to duplicate those curves today on a computer, but they aren't the only way, and aren't necessarily the best way.
 


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