Quick Sunstone query

Hi, all,

I'm just about ready to plunk down my $600 for some boards, and I have one sanity-check question for any Sunstone users out there. (I sent them an email, but haven't heard back so far.) Hopefully this will be my last noob question for awhile--thanks for your patience.

I uploaded my Eagle .brd file fine, but up comes this dialogue box asking about inner layer mapping.

The example shows a three-layer board with inner layer mapping and silk:

Inner 1: L13 + pads & vias Top SilkScreen: L20,27,28 Outline Layer: Layer 4

Here's the sanity check. The via cutouts in the ground plane are smaller than the top level pads, and if it tries replicating those all the way down the stack, every single via will be shorted to ground.

So is it "wiring + pads + vias" or just "wiring + vias"?

Thanks

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
Reply to
Phil Hobbs
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I would get one of those free gerber viewers, like Laviner or

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Check out the board your self, and make sure your thermals and annulus rings are correct.

They may ask to duplicate the inner layer for layer 3, since they will make a 4 layer board for you regardless. I never got a 3 layer in quick turn, its like deer hit with head lights.

Cheers

Reply to
Martin Riddle

The three-layer board is their example, from the example text in the entry dialogue box. (I think you have to pay for three-layer boards with three-dollar bills.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
Reply to
Phil Hobbs

Okay, boards ordered, should be here next week.

Thanks

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
Reply to
Phil Hobbs

$600 for prototype boards? That sounds rather high. Maybe you had an extra-heavy gold plating :-)

I'd have to look it up but the last ones I had made were AFAIR around $200 for a dozen, twice the size of an iPhone. Nickel-Gold plating, looks like a million Dollars.

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

Probably was. I didn't want to go through all the Gerber file stuff, and I got 25 of them. Sunstone and the other outfits that do the file conversion for you seem to charge $500 to do anything, and the boards are nearly free after that.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
Reply to
Phil Hobbs

I've never seen anything under $1000 for a dozen four-layer boards, smallish size (~20 sq. in?). Advanced typically charges around $200/board in that quantity and size.

'Course, two layer boards are cheap, same size might be under $50/ea in same quantities. But if you're getting them from, what, China, that could be really cheap.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
Reply to
Tim Williams

If it's small and simple boards then that was too expensive. Hint: Always call a rep and ask for a deal. I've often dickered out a half-off deal for clients, versus the web price that everyone else was paying. Sometimes less, but they always threw in something valuable in order to nail the deal.

Also, it does pay to run the CAM processor and ship standard Gerbers.

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

Not if you call your rep there :-)

It does help to have another quote in hand. Sometimes I was truly stunned by the difference between domestic shops. Can easily be 2:1.

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

Sparkfun offers a circuit board consolidation service -- they accept Gerbers until they have a full panel, then send the order off to China.

Way good prices, the boards have solder mask & silk, and they do four- layer boards, too (although you have to wait longer, because fewer folks know about it).

My next less-than-time-critical order is going through those guys.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
Reply to
Tim Wescott

Thanks, Tim, that is very a good hint. I did not know that they do consolidation. But if it goes to China it can only be used for non-critical and non-ITAR projects.

--
Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

Yup. But within its limitations, it looks like a good deal.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
Reply to
Tim Wescott

Hi Phil, I hope your boards turn out OK. I know a co-worker had problems with via's and internal ground planes. I've used GC gerber viewer that Martin recommended. (It's always nice to check.) Perhaps you can ask Sunstone to look over the internal layers for you before it is made.

George H.

Reply to
George Herold

They sent me some checkplots last night. I installed a copy of gerbv (part of gEDA) and had a look. They came out fine, except that I didn't manage to figure out how to get the power pad of the THS3091 connected to the ground plane. I probably need to change the part model to give it an explicit pin number.

So, God willing, I'll have boards next week.

This design is sort of interesting--it's a 100 MHz current amp that uses a Skyworks SKY65050 25-GHz pHEMT cascoded with a BFP650 45-GHz Si-Ge bipolar. I made the layout just about as tight as I dared, and kept the output away from the input, but the odds are that it'll still oscillate the first time round. Fortunately I have a Dremel to hack it up with if necessary.

The BFP650 has practically infinite Early voltage.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
Reply to
Phil Hobbs

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Yup, I tend to make two schematic bits for each part. One for signal stuff and the other power. (Which includes any power pad connections) It makes the schematics look nicer.

George H.

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Reply to
George Herold

It helps to panelize the boards. I recently wanted to have a tiny board made. I let Eurocircuits ('local' for me) panelize the board and I got 24 PCBs for the price of 2.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------
Reply to
Nico Coesel

I usually ask for a quote that implies that the minimum qty will be what will fit on a panel. So if 5 boards fit on a 12"x12" panel then that is what the quote turns out to be.

It?s a good idea to get to know the manufactures panel sizes. This way you can maximize the number of boards on a panel. Just like what the assembly houses do. just add boarders and V-scoring and your set...

Cheers

Reply to
Martin Riddle

Thats true for old-school PCB makers. Nowadays most of the quick turn around PCB makers use pooling. They put designs from different customers in one panel. IOW it doesn't matter how much or little you order.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------
Reply to
Nico Coesel

Have you thought about making your own boards? You can get a decent board in an hour(excluding etching time which varies) with equipment for under 100$. Most of the time the boards turn out good enough for prototyping if your not doing stuff below 10mil-15mil.

It's actually a very simple process with pre-sensitized boards.

  1. Create Schematic
  2. Print out mask on transparency(requires laser printer or special transparency for ink jet. Else get it printed somewhere for about 50c).
  3. Apply mask to pcb. Simply put mask over pcb and use light to create mask in photoresist. Takes about 8 mins but a few more doesn't hurt(too much and your mask becomes thinner resulting in broken traces).
  4. Remove resist using NaOH. Takes about a min or 2.
  5. Put pcb in copper etchant. Takes anywhere from 30 mins to an hour. With proper setup can be done rather quickly and decently.
  6. Remove resist completely using NaOH. Takes less than a min.
  7. Clean up board.
  8. Optionally apply your own solder resist. This is more complex and takes time if you have a lot of components unless you get your own stencils made. You can make your own stencil out of the transparency or use tape to mask off component pads. Just spray the pcb with paint or something to ask as a solder resist(there are sites and discussions for this).
  9. Drilling holes. This can go quick if they are not too small and your pads are actually annuluses to guild the drill bit. Obviously if you have a lot it will take longer. You can usually do one hole every 5 seconds which is about 300 holes an hr. Definitely not fun but you could have bought you a drill machine for the 600$ you spent.

The great thing about this is that it's cheap and you don't have to wait to get your boards. Obviously it's more work but if your spending 600$ for a

50$ worth of pcb just for prototyping then it is a much better alternative unless you've got a few money tree's and time to waste.

If your boards are completely and/or 4 layer it may not be worth it. It is possible to do 4 layer boards but requires more work. There was a site I found a while back where some guy stacked a 1 double sided with a single sided to do a 3 layer board. He used special made via's that could be punched in. You couldn't get a via on the single sided to work unless you somehow soldered it on the inside(possibly presolder the double sided board and heat up the via hoping it will melt the solder).

If you design your layout with prototyping in mind you can usually reduce the complexity and holes significantly. Use wire jumpers instead of vias. Oversized vias where wire can be slipped in. Use components as jumpers. Etc...

The great thing about this method is when you have that super anti-gravity circuit that you dreamed up overnight you can have the prototype done within

24 hours and it will only cost you a few dollars instead of a few hundred.
Reply to
Jeffery Tomas

I'm using an UV light for that purpose. I think I built it 20 years ago but it still works. Nowadays I'd buy something like through Ebay. Buying good quality pre-sensitized boards is a key factor. I also use ready-to-use developer which I keep at room temperature. I keep the exposure time short (2 minutes) and use a small spunge to wipe the exposed resist of the board. If there is still resist I expose the board without mask and develop again.

That takes long. I have a machine like this with ferric chloride:

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It uses a rotating tube with holes to spray the etchant. It works better than any etching machine I've seen before. I can literally see the copper coming off. I think etching takes less than 2 minutes. I paid ? 15 for a second hand unit. I wish I bought it 20 years ago. I used to have an immersion etching machine but that took ages to etch a PCB. Under-etching is a bit of a problem though. 10mil traces / 8 mil clearance is the minimum. Enough to be able to use 0.5mm pitch TQFP packages.

I use ethanol for stripping the resist. Less hassle.

Every now and then I etch board myself when I need it fast (and even then only for prototypes or tinker stuff). Most of the times I just have a board made.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------
Reply to
Nico Coesel

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