PCB Designing

While the below is me nattering on about my history with PCBs, if you scroll down a bit I do discuss PCB designing software and also Chinese suppliers.  If this information is useful to you, scroll past my general chitter chatter and see what you came here for.  If you want to jump to the PCB Fabrication Companies, click here.

 

In the beginning when I created electronic projects, I soldered wires onto many different components and modules, often on stripboards cut up and it was always a bit of a mess.  Nothing looked good and unless I used a hot-glue gun, things would never last for year or more.  Then in 2015 I decided to look at designing PCBs and etching them myself.  I looked at the designs of a UV light box and then made one (you can view that project here), I bought the chemicals to etch online and some blank PCBs.  I then designed the PCBs in Corel Draw, printed onto acetate sheets and away I went.  I also bought a mini drill with a bench style rig and a load of Carbide Drill Bits.

Sadly creating your own PCBs at home isn’t the way to go.  I spent ages and a fair bit of money on the project, but the results were bad.  I would often get one usable PCB for every 20 that I made.
One PCB that I made is shown below.  You can see the bottom half of the board is ok, but the top is bad, so bad.  My finger in the photo is me pointing at a 0805 SMD resister, it was the first surface mount component that I ever tried to solder and I was so happy it went on!  the PCB was rubbish, but the SMD looked great…

 

I was so upset with my success rate I decided to do some internet searching over companies that do PCB printing as a service as I assumed there must be some out there.  I was not wrong, there were quite a few & I was shocked over the price.  At the time, I found two companies in the UK and they were charging £400 for a set of 20 boards of the size on 5x5cm.  Whereas in China they would charge around £20 for the same size.  I obviously couldn’t afford the UK price, so thought I would give one of the Chinese companies a go.

The first company I used (sorry, I can’t remember who it was) was a bit dodgy, their screen printing wasn’t very sharp (photo at the bottom of this page) and some of the etching wasn’t as precise as I now expect today.

 

 

PCB Design

The first thing you need to have if you want to design your own PCBs is CAD software that is dedicated to PCBs.  Don’t go to software that has it as an add-on as it will miss things and will not be as good.
For me, there are only two contenders and that is Eagle and KiCad.  Eagle is a professional package which is paid for, but they do have a cut-down version for home users.  This program seems to be more the standard around the world.  I say this as when I have seen people giving out designs on web sites, they tend to be Eagle files.  I have seen some KiCad files out there, but not as many.
I use KiCad myself and I love it.  I have no interest in trying Eagle as KiCad does everything that I want and I know how to use it

Eagle’s can be download it here.
Kicad’s can be download it here.

Once you have chosen with program you are going to use, you need to learn how to use it.  This is a very time intensive project just by itself.  Be warned, it took me a couple of weeks of learning and playing before I attempted to make my first board which is shown below.

 

 

Learning PCB Design software

PCB design is not something that you should just have a go at.  Yes, you might figure it out by yourself, but it will take a lot longer and you will miss things that you need to know from the start.  Spark Fun have made some great instruction for Eagle which you can see here https://learn.sparkfun.com/tutorials/using-eagle-schematic/all.  For KiCad, there are many YouTube video training session out there, this one I found quite useful https://www.youtube.com/watch?v=vaCVh2SAZY4.  One thing that I would always recommend if you want to start designing PCBs is to have two screens on your computer minimum.  There are times that you will want to have the Electronic Schematic n one screen while you lay tracks on the PCB on the other.  Don’t get me wrong, you can do it with just one screen and switch between the different screens, it will just take you lomger.

 

 

The Basics on creating a PCB   (using KiCad)

The steps to design a PCB is always the same:

Step 1 – Electronic Schematic
You will need to sketch the design of the components you will use and how they connect to each other.  You can use components from the already very large library or you can create your own.  I always then put a box around the different groups and label them to remind me the different modules.
For the below example I will use the first test PCB that I made back in 2015.  It is a simple bard to test out LEDs using different resistor values, a voltage regulator setup and also a relay test (push button to activate), a load of different sized through holes and then a few random templated that I made for components.

 

Step 2 – Annotate your components
This is an automated thing when you click on a button.  All it does it assigns a number to each of your components, so if for example you have 4 resistors, they will be labelled R1, R2, R3 & R4.  This is very important for the next step.

 

Step 3 – Linking PCB templates to Electronic components
Once you have finished your design (or at any point during the design work to keep updating it), you need to link a PCB component template to your electronic component.  You do this as let’s say you had a 2-pin LED on your electronic schematic.  Is the device you are going to use a 3mm, 5mm or surface mount device?  Here you tell it what you will be using.  Again, like with the electronic schematic, you can select PCB templates from their vast library or you can create your own.  I decided to copy all of the templates that I use into a custom made library (called ‘0_Custome_Parts’) and I also have made a great deal of PCB templates for parts that I use.

 

Step 4 – Build the Netlist
Like with annotating your components, this is just a click of a button.  This will create a file that contains all of the PCB component templates that your project uses, all of the pins for them and what connects to what.  This can then be passed to the PCB Layout Editor.

 

 

Step 5 – Designing the PCB
This is the part I love the most.  Once the net list is imported, all of your components will be placed on the screen and it is up to you to move them (and rotate as required).  You can then place tracks on the top or the bottom of the board to connect everything up.

 

3D Render
You also have the ability to generate live 3D renders for your PCBs.  If any of the component templates you are using also have component 3D renders, it will display that too (like the LEDs, Resistors, Capacitors and Semiconductor below).  When you move components or tracks, come back to the render screen and it will instantly change.

 

 

Step 6 – Ordering your PCB
Once you have your design complete you need to generate the GERBER and Drill file.  This is just a click of a button, it will generate a few small files for you that you will need to .zip up.
The last stage is to send the .zip file to a production company and place an order.  If you scroll down to the bottom of the page I talk about the suppliers that I have used.

This is the actual PCB.  It isn’t bad, but the screen printing isn’t that great quality.  Look at the ‘Relay’ in the top left corner and then all the components and lines below it, it is very patchy.

 

This is the board assembled.  It is very basic, but as my first ever board, it was just a test.

 

WARNING
Please remember that you will be working potentially with very small devices.  It is possible that you have used an existing PCM component template or you may have created your own.  It all looks good, you send it off to get made up, only to find out that you have some sizing wrong and things don’t line up.  Below shows on the left and right my USB connector where the frame lugs don’t line up with the PCB.  I had to use superglue in the end as there was not enough solder to hold it down securely.   This will happen a lot potentially.  The middle photo shows that I had to solder pin one and 2 together as I got the schematic wrong as I thought it was pin 1 I needed, but it was actually pin 2!  You are going to make all sorts of errors in the beginning and from time as you progress.  In KiCad you can print your PCB design on your home printer at a scale of 1:1 (make sure the scale is that as otherwise it won’t print it the real size).  From the printout you can place all of your components and using a magnifying glass you can check that all the solder lugs and holes do match up well.

 

 

PCB Fabrication Companies

So, big question, who should you use to make your PCBs?
I have no affiliation with any company, I do not receive kickbacks, discounts, coupons or any sort of payment or income from any suggestions I give below.  I don’t even have any custom links to them.  The information below is from my own experience with the companies.  I may have great success with one company, while other people hate them as they have had issues.  Sometimes it can just be luck or bad luck.
All of the companies I use are in China.  The production and shipping times are all about the same.  Sometimes I order things and they come in 2 weeks, sometimes 6 weeks, but usually they are all around 3-4 weeks turn around.  When deliveries have taken  a long time, I have not blamed the company themselves as I think it all depends on when they leave China in the big container as I do think they ship country to country in blocks, so it is luck of the draw on how long it will be before you get them.

Where I show prices below, they are correct as of January 2021.  They are for a 10x10cm PCB with the standard options that incur no extra charges.  Also please not that it is also usually best to order 2 or 3 PCB designs at the same time as the shipping charges will either be the same or only slightly higher, so in the long run your price per PCB will be much lower).  Another thing to note is if you want more than 10 PCBS, it can be cheaper to place multiple orders of 10 rather than buying say 20 in one order.

 

As to PCB colours, below are some that I have had made.  Black is good if you want to hide the track whereas red makes the track stand out.  I usually go for Black on most of my boards for no reason other than I like it.

White/
Black
Blue Red Green

 

 

 

Seeed Studio
Web site: https://www.seeedstudio.com/fusion.html
This is my preferred supplier.   Their cheapest board is 10x10cm.  You can also choose what PCB colour you use from Green, Red, Yellow, Blue, White & Black for no extra charge.  The standard finish is HASL, if you want lead free, that is an additional charge.  They also have a built in Gerber viewer, so you can check your board out with their system.

Cost: $4.90
Shipping: $11.83
Total: $16.73  (£12.26, so £1.23 per board)

 

 

 

Elecrow
Web site: https://www.elecrow.com/pcb-manufacturing.html
My second choice in companies.
Elecrow is very much like Seed Studio in many ways.  Their price structure starts at a 10x10cm board.  You get to choose your PCB Colour from Green, Red, Yellow, Blue, White & Black for no extra charge.  Their standard finish is HASL, you can select HASL lead free for a charge & a smaller charge than Seeed Studio.  There is a $5 charge for HASL lead free.

Cost: $6.90
Shipping: $13.94
Total: $20.84  (£15.28, so £1.53 per board)

 

 

 

Smart Prototyping
Web site: https://www.smart-prototyping.com/PCB-Prototyping.html
My third choice in companies.
The standard PCB colour is Green. If you want any of the other colours that Seeed or Elecrow want, you will be charged £8 extra.

Cost: $9.90
Shipping: $13.45
Total: $23.35  (£17.12, so £1.71 per board)

 

 

 

 

PCB WAY
Web site: https://www.pcbway.com
Many people rate this company as being the best.  I tried to use them for a project in 2020 and ended up having an argument with one of their sales guys as he kept telling me that by GERBER file was the wrong format and I needed to change it.  I checked and it was fine.  He said that my file needed to be in RS-274X format, but what I sent was X2.  I checked with other vendors and their automated systems could read it.  Two hours later the sales guy came back to me saying that my file was obviously RS-274X format which was wrong as they needed X2.  I went back asking why he keeps changing his mind over what they need as first he said they needed RS-274X, then he said they need X2!  His last message was (quote) “Did I not speak clearly enough or did you not understand at all?  I mean the file format you uploaded to our website is X2, we can’t open it, we need the RS-274X format.”  What he said two hours before was “The file you upload should be in X2 format, not RS-274X format.“.  Arguing with somebody for half a day is not something I have time for & that is why I will never use their company again.

To be fair, I will list their pricing though so you can have all of the information.  They also have the same PCB colour range that the others have at no additional cost.

Cost: $5
Shipping: $19
Total: $24  (£17.59, so £1.76 per board)

 

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