Jump to content
Mark Easley TI

Best PCB maker for prototyping?

Recommended Posts

I also use DipTrace.  I find that the signal routing is a lot nicer in DipTrace than it is in Eagle: easier, faster, better coloration and graphic display.  It has some quirks, but for manually routing tight spaces and pours on multilayer boards, it is the way to go unless you want to pay for Altium.  I've done 5/5 bug-free boards with DipTrace, and the boards I do are reasonably dense -- great DRC.  This makes sense, since the guys who made DipTrace have roots in CNC and machining.

Agreed, and I didn't know the guys who wrote it came from CNC backgrounds :smile:  Come to think of it I also haven't really checked what else their website & forums have to offer in terms of footprints/libraries et al... I usually roll my own.  But it's been a joy to use so far!  The different ground plane options are also nice, I typically use a crosshatch pattern for my home-etched PCBs (although my Samsung printer could probably handle a solid ground plane with its heavy-toner setting anyhow).

 

Also agree with the DRC, it has never let me down with homebrew or commercial PCB making.

Share this post


Link to post
Share on other sites

No, not by design, you get what you pay for I guess :smile:

If I'm buying a 5x5cm 4-layer board with ENIG finishing, it comes-out to $6.5 per PCB. That's pretty freakin cheap. HASL is IMO not adequate for lead-free solder reflow, and for any kind of SMD hand soldering it is a nightmare. Therefore, I'm not even considering it. ENIG is a base requirement for me.

 

Let's compare OSHpark. The cost at OSHpark is $13.3 per 4-layer board, which includes ENIG and the same DRC tolerances, but with no caveats about how you should design for 0.2mm space/trace despite the fact that 0.15mm is in the DRC. Moreover, the end product from OSHpark seems to be top-quality, in all the experience I have with them. My verdict is simple: if you are cool with purple and you only want 3 boards, OSHpark is not only a higher quality product, but it's also cheaper. If you want more than 3 boards and you don't have designs with 0.15mm space/trace (I generally do), Elecrow is the better deal.

 

Ultimately, neither is really suitable for high density boards or UHF RF boards, since the min drill is 0.3mm, stipulating a min via diameter of 0.66mm. If I want to drop vias every 0.01 lambda, guess what, not advisable for designs above 600 MHz. There won't be adequate room for the internal copper pours. For the RF boards I do, I go with 0.15mm min drill and 0.15mm min space/trace. You'll notice this is the norm on any RF board you buy.

Share this post


Link to post
Share on other sites

My RF knowledge is quite dusty, but I remember 300MHz equals a lambda of 1 meter. So 600MHz gives lambda of 500mm, at 0.01 lambda that would become every 5mm, which is about 0.2" (5.08mm is exactly 0.2"). This is half the pitch density of proto PCB. I guess you mean 0.01 of lambda/4, which would be about 0.05" pitch, which is equal to the pitch of the ez430 connector. This is still doable, but going higher (868MHz anyone?) might pose problems.

 

ENIG is very nice, but I mostly have not much problems with HASL (unless using QFN or BGA packages), just make sure you cleanse the board of oxidation before starting to solder (solder tends to oxidate quite fast). And I try to avoid going over 2 layers to press the price down.

Share this post


Link to post
Share on other sites

Ive used both enig and hasl many times in the past. Just recently hand soldered a board with HASL using leaded solder and had a qfn44 device on it. Have to admit that it wasn't easy to do and I'm sure that I would have had much better luck with enig. Especially considering the poor surface flatness of HASL and how that affects how the Qfn lays on the pads prior to soldering.

 

I'm cheap though so regardless of what I just said ill probably still get HASL and suffer :)

Share this post


Link to post
Share on other sites

My RF knowledge is quite dusty, but I remember 300MHz equals a lambda of 1 meter. So 600MHz gives lambda of 500mm, at 0.01 lambda that would become every 5mm, which is about 0.2" (5.08mm is exactly 0.2"). 

The dielectric effect of the PCB affects the wavelength by multiplying by half, in most cases.

 

So, each 2.5mm will have 0.7mm used by vias, and usually 0.4mm for clearance.  This can be OK, but remember that there are also traces to deal with.

Share this post


Link to post
Share on other sites

Just an Update: I emailed Seeed on the 8th about the solder mask issue. They asked for pictures, I sent some on the 13th. Just today I received a reply back basically saying they don't do smd solder masks?

 

Hello,

Acturally we do not do the solder mask between the pads.

And do not have the regulation about this.

 

Even though my "SMT min Solder Mask Width" is bigger than the 0.1mm/3.94mils limit.

 

I asked them to confirm, but it looks like they either don't care, or the manufacturer specs they list are not what they can actually provide.

Share this post


Link to post
Share on other sites

I was doing some research on that the other day - ran across a post somewhere that said that no solder mask between tiny smd pins is normal.  I'm using a QFN part for a board - and the default Eagle stop mask expansion overlaps between pins.  

Share this post


Link to post
Share on other sites

In a recent order with elecrow I specifically in the "comments" asked the fab to not modify my soldermask, and the boards came back with mask between the legs just fine, they do that so they can be lazy and not worry about the soldermask alignment as much

Share this post


Link to post
Share on other sites

This is my research for 100x boards:

  1. Seeedstudio (China) = ~$100 + 3 weeks shipping
  2. U&I (S.Korea) = ~$200 + 1 day shipping
  3. Crimp Circuits (Toronto) = ~$700 + 1 day shipping
  4. APCIrcuits (Calgary) = ~$950 + 1 week shipping

Subjectively, I think that U&I was the best combination of board quality and shipping over cost. 

 

Sure, I'm not making 10x boards so maybe this is an apples to oranges comparison.

 

Still, the board quality from U&I is absolutely fantastic. Truely professional quality.

 

I will be going back to U&I for future jobs.

Share this post


Link to post
Share on other sites
This is my research for 100x boards:

Seeedstudio (China) = ~$100 + 3 weeks shipping

U&I (S.Korea) = ~$200 + 1 day shipping

Crimp Circuits (Toronto) = ~$700 + 1 day shipping

APCIrcuits (Calgary) = ~$950 + 1 week shipping

Subjectively, I think that U&I was the best combination of board quality and shipping over cost. 

 

Sure, I'm not making 10x boards so maybe this is an apples to oranges comparison.

 

Still, the board quality from U&I is absolutely fantastic. Truely professional quality.

 

I will be going back to U&I for future jobs.

 

How big were the boards for comparison?

 

Sent from my C3PO via Tapatalk

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×