[sdiy] PCB / Panel Manufacture

Daniel Roberts danmroberts at gmail.com
Fri Feb 7 18:34:48 CET 2020


I think that copy just hasn't been updated since they started offering
black boards. Elsewhere on the site:

"OSH Park manufactures entirely in the US and isn't affected by Lunar New
Year."

On Fri, Feb 7, 2020 at 9:06 AM mark verbos <mark at verboselectronics.com>
wrote:

> "Our purple boards are manufactured in the USA and shipped free to
> anywhere in the world.”
>
> seems to suggest that the black/clear ones are not. In case that matters
> to you…..
>
>
>
> Mark
>
>
>
>
>
> On Feb 7, 2020, at 12:47 PM, john slee <indigoid at oldcorollas.org> wrote:
>
> Not anymore! They now have a black substrate/transparent soldermask
> option. I used it to make a PCB panel recently, with a copper flood-fill on
> the top layer, and (I think) it looks absolutely lovely
>
> Hopefully this image attachment thing will actually work...
>
> John
>
>
> On Fri, 7 Feb 2020 at 21:55, Sarah Thompson <plodger at gmail.com> wrote:
>
>> OSHPark manufacture in the US and are cheap and fast. I used them a lot
>> when I worked at NASA for prototypes. They can work with EAGLE easily. I've
>> also used them for front panels by designing the panel as a PCB -- this
>> works pretty well. One peculiarity is that all their boards are purple,
>> which you may or may not like! :-)
>>
>> On Fri, Feb 7, 2020 at 7:56 AM <rsdio at audiobanshee.com> wrote:
>>
>>> Hi Shawn,
>>>
>>> Eagle will work fine. Basically all of the fab houses accept Eagle
>>> files, and certainly all of them support Gerber files produced by Eagle.
>>> Eagle has all of the features you need to make professional boards. It will
>>> take you a long time to learn everything, but everything can be done in
>>> Eagle. There are some commands and key combinations that are esoteric, but
>>> nearly all CAD software is like that, except for some of the newer programs
>>> (but those are less than fully professional). Your best bet is to find the
>>> online support forum for Eagle, read the documentation, and ask questions
>>> if you can’t find answers to your questions in the archives of the forum. I
>>> purchased Eagle before it became subscription based, so my license has no
>>> limitations. I don’t know whether your license is size-limited,
>>> layer-limited, page-limited, or otherwise limited. So, unless you run into
>>> limits, I recommend treating Eagle like a new synth that you dive into and
>>> learn absolutely everything you can about it.
>>>
>>> Keep in mind the size constraints of Eurorack. You don’t want breakaway
>>> tabs on your PCB interfering with modules next to yours. Same thing with
>>> face plates, although Dieter covers this on the doepfer.de site.
>>>
>>> I order all of my PCB designs from USA-based fabrication houses.
>>> Prototron is near me in Redmond, WA. They’re probably the most expensive
>>> I’ve ever used, but they’ll make a deal for quantity. Sunstone Circuits in
>>> Oregon has some bargains, but it really depends upon your size. Advanced
>>> Circuits, a.k.a. 4PCB, have some decent deals on prototypes, and their
>>> quality is way above the cheaper places. I can literally see the quality
>>> different with the naked eye when comparing an Advanced Circuits PCB with
>>> my exact same design files made by a cheaper fab house. OSH Park probably
>>> has the best prices in the USA, but you’ll wait longer than anywhere else.
>>> Their quality is really good - probably all you’ll ever need - but they’re
>>> not top quality.
>>>
>>> Once nice thing about 4PCB is their FreeDFM site that will check your
>>> Gerber files and report errors. There’s no charge to use the site, but
>>> you’ll get one email asking if you want to buy the boards. I’ve never
>>> received more than one advertising email, though, so I often use them to
>>> check a design even when I order somewhere else. This is a good way -
>>> especially when you’re just starting out - to get an idea of whether your
>>> PCB is following standard design rule
>>>
>>> Speaking of fab houses and Eagle, make sure you find and download a DRU
>>> (Design Rules) file for each of the sites that you want quotes from. OSH
>>> Park and Sunstone Circuit actually have the files on their web sites.
>>> Advanced Circuits describes all the constraints textually, and if you study
>>> how to edit the data in Eagle then you can create your own DRU for Advanced
>>> Circuits orders. Before ordering any new PCB design, make sure you change
>>> the DRU selection to point to the file describing the specific fab house
>>> that you want to order from, and run the “dru" command to check for
>>> violations. You might have to change trace sizes or move things around to
>>> fit the capabilities. Sometimes, the minimum drill size makes your vias
>>> larger, and then everything has to be spaced further apart. FreeDFM will
>>> catch this, but you can catch almost all of the same issues inside Eagle
>>> before you upload anything. Eagle remembers which DRU file you’ve selected
>>> for each PCB project board file, so you can order from different places.
>>>
>>> Some people think PCB fab options are as simple as: China is cheap, and
>>> USA is expensive. Some people even think that all PCBs are made in China
>>> even when you order from a USA company. Sometimes this is true, but not
>>> always, and there are other factors. For one thing, TSA can randomly hold
>>> up your PCB order at the border, and then you’ll be waiting longer than OSH
>>> Park (OSH Park is my benchmark for “long wait times"). I had one customer
>>> order from the cheapest Chinese PCB shop, and then screamed bloody murder
>>> when TSA held all of the boards for weeks, maybe months - delaying their
>>> product manufacturing. You might pay more in USA most of the time, but it
>>> might also really be worth it to you when you consider everything like
>>> time-to-market.
>>>
>>>
>>> I’ve made several panels, both for 19” rack electronics and for
>>> Eurorack. I’ve ordered everything from Front Panel Express in Seattle.
>>> They’re somewhat expensive, but if you pay attention you can keep the price
>>> reasonable. For one thing, it seems really expensive to add paint in etched
>>> lettering, and so I’ve never paid for that. However, if you just spend a
>>> few cents extra for anodized aluminum, especially black, then etched
>>> lettering will reveal the bare aluminum color behind the anodized surface,
>>> and then you don’t need to pay for paint to make the letters visible via
>>> contrast. Front Panel Express will also screen print any image, but I’ve
>>> only used that for projects where I have the extra budget - it’s not cheap,
>>> either.
>>>
>>> Front Panel Express has a free application that you use to design the
>>> panels. It’s probably a really bad idea, because I don’t know whether you
>>> can import or export designs from other design tools. Since I’m only doing
>>> prototypes, I don’t worry too much that all of my designs are in a
>>> proprietary format. However, it is really convenient that you can get price
>>> quotes within the app, and they’re even itemized so you can see what
>>> determines the cost and sometimes even delete or change features that are
>>> too expensive. Sometimes it’s a slow process to quote all of the variations
>>> appropriate for a given design, but if you’re cost conscious then it’s
>>> probably worth the time to research.
>>>
>>> One cool thing about Front Panel Express is that if you screw up a panel
>>> in a way that you can fix it by cutting more away, then you can save money
>>> by sending back the original panel for them to cut changes. That ends up
>>> being cheaper that ordering a second panel from scratch, but you really
>>> have to work extra hard to create a design that includes just the
>>> differences between the old mistakes and the new desired panel. I realize
>>> this is probably only a practical option when you live close enough to
>>> drive by, drop off the old panel, and pick up the new one later. They have
>>> free shipping for large orders, but when you’re saving money you have to
>>> think about the cost of shipping when your total is below their free
>>> shipping minimum. Obviously, though, you can’t fix a panel after you’ve cut
>>> too much away - there’s not a drill that can add aluminum back on the face
>>> plate.
>>>
>>>
>>> For both PCB and panel designs, you want to make careful measurements of
>>> all mechanical parts, particularly screw holes, screw placements, and drill
>>> sizes. Not only do you have to align the components with the boards and
>>> panels, but you have to align the boards and panels with each other.
>>>
>>> In Eagle, I tend to create extra layers, or use Documentation or
>>> Reference layers to draw the mechanical parts that are not actually part of
>>> the PCB. This helps me get an idea of how things will fit together later.
>>> Of course, there are work flows that allow you to create 3D data for your
>>> PCB design. Eagle is compatible with that, and I know people doing it, but
>>> I haven’t taken the time to learn. Besides, you still need to create 3D
>>> models for the face plate and other mechanical components, and that seems
>>> like a lot of work unless you’re using the exact same parts as everyone
>>> else.
>>>
>>> You have to get used to the fact that some parts are measured in metrics
>>> units, and others are measured in English units. Within Eagle, I frequently
>>> switch my measurements between Inches, Mils, and millimeters. It’s a pain,
>>> because I don’t know how to change the units after calling up the editor
>>> for a component placement, so I just cancel the dialog, switch units, and
>>> then open the dialog again. Once I get all parts that touch other parts
>>> aligned properly, I use the Eagle “lock” tool to prevent those parts from
>>> being moved accidentally. Components that only mount on the PCB and nothing
>>> else are left movable.
>>>
>>> Meanwhile, FrontDesign.app also allows English and metric units, and
>>> again is a bit of a pain because I find that you always need to mix both in
>>> the same design. Eurorack is a bizarre mix of English units and metric.
>>> Even though the numbers are almost always reported in millimeters, it’s
>>> fairly obvious that 1 HP is 0.2” (1/5”), so I often check placements on a
>>> 0.2” grid.
>>>
>>> There are lots of things to learn, but these days we have the internet.
>>> I recently had to figure out what size hole to drill to guarantee the
>>> standard amount of room for an M3 screw and an M6 pot shaft. Sometimes the
>>> data sheets for the electronics components will tell you these things.
>>> Other times, you just have to ask the industry what’s a standard drill size
>>> for an M3 screw.
>>>
>>> Personally, I prefer solid aluminum to a PCB for front panels. Granted,
>>> you can order a multilayer PCB and dedicate a solid copper layer to shield
>>> your electronics from emissions, but it seems a lot easier to keep out
>>> noise with a solid metal enclosure. For Eurorack, that means a metal case
>>> and metal face plates. But there’s nothing wrong with using Eagle to design
>>> cool face plates.
>>>
>>> You can even change the colors of the layers in Eagle to get a rough
>>> idea of how the finished product will look. I designed a product where the
>>> internal boards have black screen print on clear solder mask, and the raw
>>> copper and FR4 material shows though. OSH Park has an option now with black
>>> PCB material, white screen, and clear solder mask that looks crazy - you
>>> really have to think about how it will look before you order.
>>>
>>>
>>> One weird thing about Eagle is that Devices seem to require all Symbols
>>> and Packages to come from the same library file. So, you can make your own,
>>> but if you want to borrow an existing Package for your Device, you’ll have
>>> to copy that Package into your library. I recommend building your own Eagle
>>> parts library, and back it up regularly. I actually use revision control,
>>> just like I do for source code when doing computer software design, to keep
>>> track of my own Eagle library files. That way, I can recover an old
>>> version, and can work on multiple computers and know that I have the latest.
>>>
>>> There are Eagle libraries available for free, and they’re sometimes a
>>> time-saving starting point, but never trust that they’re correct. Whether
>>> you create the packages yourself, download them from the Eagle community,
>>> or mix and match, you always want to study the data sheets for the
>>> electronics parts, direct from the manufacturer, and make sure all
>>> measurements are correct. Here is where you learn that you can’t make the
>>> drill size the same as the through-hole lead size, because it will be too
>>> tight once the copper plating, board finishing and tinning are completed
>>> and the hole gets smaller.
>>>
>>> Regarding data sheets, I recommend that you *always* go directly to the
>>> part manufacturer’s web site, search for the exact part you’re using, and
>>> download the latest data sheets for the stuff you’re using. Trusting Mouser
>>> to have the latest information, or some internet aggregator that wants to
>>> sell you knockoff chips, is not the way to get your design right. It takes
>>> almost exactly the same amount of time to download the data sheet from the
>>> wrong source as it does to download it from the right source. Once you do,
>>> keep a backup of those files for future reference, and keep the files
>>> organized so you know what you have. On that note, I currently have
>>> approximately 2,838 data sheets from 218 different manufacturers under
>>> ~/Documents, and I have a few backups of those.
>>>
>>> Most of them have recommendations somewhere for PCB design for their
>>> parts, but a lot do not have any hints. That’s partly because the proper
>>> way to design is highly dependent upon the process used by your particular
>>> PCB fab, and when you change fab houses you might need to actually change
>>> your PCB design to accommodate.
>>>
>>> Some companies like Analog Devices and Texas Instruments also have
>>> Application Notes and even electronics design articles from excellent
>>> engineers who will explain many of the things you need to know to design a
>>> PCB. You have to start by reading the entire data sheet for the parts
>>> you’re using, and follow every link in that data sheet to the other
>>> documentation from the manufacturer on related information that you might
>>> need.
>>>
>>> As for whether you need 2 oz copper, or super wide traces, there are
>>> probably plenty of articles online that will discuss that.
>>>
>>> Brian Willoughby
>>> Sound Consulting
>>>
>>>
>>> On Feb 6, 2020, at 7:31 PM, Shawn Rakestraw <shawnrakestraw at gmail.com>
>>> wrote:
>>> > Hey All! I'm new to the list and this is my first question.
>>> >
>>> > I want to dip into making some PCBs and possibly front panels. I am
>>> into eurorack, so that is what I will be aiming toward. I have been
>>> learning how to use Eagle to make my schematic into a board.
>>> >
>>> > Currently, I have been working on a power supply PCB that would mount
>>> inside of a case, so I don't have any major size constraints or precision.
>>> I will probably make a simple bus board next to distribute the power. Then
>>> I want to move on to an actual module. Something simple at first.
>>> >
>>> > I should also mention that I am in USA, although that probably doesn't
>>> matter that much anymore. I do prefer to order things in the US when I can
>>> though.
>>> >
>>> > I am asking for any advice at all really. My question begins with who
>>> / where to order from, but after that I am a bit in the dark about what to
>>> even ask. I don't know if copper trace thickness should be a concern.
>>> Obviously with power PCBs and distribution boards you want wide traces and
>>> I have done some research to try to learn how wide for certain amp loads.
>>> Really, any advice will be good for me - anything that you wish you had
>>> known before your first order could be helpful.
>>> >
>>> > Has anyone made panels and if so, what is the beginning process for
>>> that? Can you design them in Eagle using Nets or something? I don't know
>>> how people even design them.
>>> >
>>> > Thanks in advance, I look forward to your replies!
>>> >
>>> > - Shawn
>>>
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>>
>>
>> --
>> [s]
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