Author Topic: First time with Diptrace and OSH Park. Success.  (Read 4089 times)

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Offline rfclownTopic starter

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First time with Diptrace and OSH Park. Success.
« on: June 20, 2022, 12:26:02 am »
With 8 employers through the years, there have always been dedicated PCB designers, so I've never had to learn a PCB tool properly. At one place I used a router to mill out prototype boards, but I just pushed polygons around in ADS to do the artwork (wasn't tied to a schematic except for some microstrip structures). I did use Eagle to do a couple boards many years ago, but didn't keep up with it. I do mostly RF, and I often just use x-acto and/or dremel to make simple stripline proto boards. A few weeks ago I set out to take the plunge and learn a tool to make a board. I don't like what's happened to Eagle, so I didn't go that route. I downloaded KiCAD, but it barfed on the Win7 computer I was using. Then I downloaded DIPtrace. I have to say that with only the video tutorial I was able to make a board fairly easily. Made footprints for two couplers, a SAW filter and an edge mount SMA. The only thing I found strange, and I don't know what it's like in other tools, but to place a bunch of ground vias when I was done routing, I had to connect them to ground for the copper flood to work.

After Googling I picked OSH Park for the board house. Used 4 layer to get reasonable 50 ohm microstrip width (19.3 mil, 31 mil gap to ground). Not much discontinuity with 0402 series part, and I can cross the gap with a 0402 if I need a shunt somewhere. Since 19.3 mil was narrow for my SMT center pins, I dropped the ground reference below the SMT center pin to layer 3 to make a wider 50 ohm pad.

Everything went well. Cost was $11.50 (free shipping, 3 boards). Bare board shown with a couple of the parts to be mounted (brd.jpg). I decided to reflow on a hot plate with some Zephpaste 63/37 that I bought many years ago. I tried first with a few of the 0 ohm resistors. After reflow, slip board over to metal plate. That went ok, so I did the other parts. Used a dental pick to put paste on pads. Not a great way, but for doing only one board, it worked. Hand soldered the SMAs.

The board is to test a GPS notch filter topology. It can be configured for four different arrangements (large or small coupler), one or two SAW filters. I only had a few SAW filter samples, so I wanted one board to test all arrangements. Simulations suggested that the large coupler with one SAW would be the winner (which it was), but I wanted to try out all possibilities. Simulated results with s-parameter component models (didn't model any board traces) matched measurements reasonably well. Tweaked inductor to get more rejection at 1575 MHz.

If I do another test board like this, I think I'm going to try JCLPCB. They have a 4 layer stackup where layer 3 isn't so far from the top, so if I want to drop a ground reference for an edge mount SMA I can make the pin trace more like 30 mils. This board was for 1.6 GHz, so I wasn't too worried about the microstrips, but I also do some things at 6 GHz.

From this experience I would recommend DIPtrace and OSHpark to anyone wanting to learn a PCB tool to make a simple inexpensive board. The free version is "two layers", but it is unlimited for power planes, so this I guess is considered a one layer board (even though there are cut outs on layer 2, and solder pads on the back). OSHpark had a large copper to outline space, so I did file the board edges so that my SMA launch wouldn't have a gap.
« Last Edit: June 20, 2022, 02:48:08 am by rfclown »
 

Offline jpanhalt

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Re: First time with Diptrace and OSH Park. Success.
« Reply #1 on: June 20, 2022, 07:39:18 am »
I can recommend OSH Stencils as a domestic stencil supplier  ( https://www.oshstencils.com/# ).  It's not part of OSHPark but they are friendly.  I got very fast turnaround at reasonable cost for an SS stencil.
 
The following users thanked this post: mlloyd1

Offline mlloyd1

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Re: First time with Diptrace and OSH Park. Success.
« Reply #2 on: July 18, 2022, 09:31:28 pm »
thanks for sharing your experiences. i like diptrace also, but I'm slowly migrating to kicad.
not there yet though. haven't sent any diptrace files out for production yet (just made my artwork for toner trace PCBS at home), so nice to see it works well with a popular board maker.  :-+

mlloyd1
 


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