Right tools, Patience and Practice is all what you need . . . .
Step 1: Making P.C.B. -- Ah... Not a Big Deal !
I always thought that making P.C.Bs at home is a very hard and exhaustive process ..
but I was wrong.. It is pretty simple thing to do, provided you have the right tools with you and of course PATIENCE !!
Earlier when I was just a novice in electronics I used to construct whole circuit on Veroboard or perfboard (the one with readymade wholes and copper pad around every hole). Then one day I figured out that I can make my own PCB at home... so why not give it a try? Then I ended up making my own PCBs using etch resistant pens, ruler and copper clads. I used to draw the layout directly on the copper clad using the pen but I always used to loose some tracks on the board in the process of etching as the ink would not sustain on the board for a very long time which only used to up my frustration.
Eventually I learnt the art of making good quality PCBs at home using right kind of materials and tools and I am going to explain this process today in this instructable which I hope would be usefulto all those novice electronics lovers and DIYers!!
Step 2: Bill of Material
Here is the list of things you would need to make a good quality P.C.B
- A good quality copper clad(Preferably FR4)
- Monochrome laser printer
- Software for drawing the circuit layout (I use express PCB , its free and satisfies all needs)
- High quality high gloss photo paper
- FeCl3 -- Ferric chloride powder or chunks and water
- Hand PCB drill or Electric PCB drill with bits of size 0.8 mm , 1 mm and 1.2 mm
- Soldering iron and soldering wire
- Good quality flux
- A pair of surgical hand gloves
- Sand paper (Grit 400) -- very fine preferred.. you may also use 800
- A scrubber (Normally used for cleaning utensils in the kitchen?)
- A sharp blade/knife -- for clearing out the periphery of the holes drilled
- Hack saw blade -- for cutting the copper clad to required size
- Scissor -- for cutting the photo paper/sand paper
- An iron -- The one used for pressing clothes
- Clean cotton cloth
Step 3: Let Us Start !! Drawing the Layout and Printing
- Take a PCB design software of your choice and make the circuit layout carefully as per the requirement.
- Once the layout is finished.. just give it a final check and then it is ready to be printed.
- Use a good quality monochrome Laser printer and of course a good glossy photo paper and print the layout on the photo paper
- You can set the printing preferences before printing. Select DARKER option if possible.
Step 4: Copper Clad Preparation
Here we will see how to make copper clad ready for printing the layout
The copper clad has to be bigger in size than the actual required PCB size, so do not cut it to actual size before transferring layout to it.
- Rest the PCB on a flat surface copper side facing up.
- Take 400 or 800 Grit sand paper piece, double fold it and start rubbing it on the copper surface from left to right and right to left in a slow continuous motion.
- This will remove all impurities, dust, stains away from copper layer and it will start giving a bright shiny look.
- Do not use a circular motion. Stick to either left to right or up down motion. Don't mix 2 types of motions.
- Do this for the entire board till it shines. Beware.. Too much scraping/rubbing will make the copper layer thinner.. We don't want to do that.
- Now wash it in soapy water and then by clean water and then wipe it with a clean cloth.
- Cover this board with a cling film and keep it aside, to be used later
Step 5: Transfer the Layout
Now its time to transfer the printed layout on to the copper clad.
- Take the printed layout and cut it to the size using scissor
- Take the prepared copper clad, remove cling film and place it copper side up on the ironing table
- Make sure to place a double fold of a Turkish bathing towel below the copper clad(This takes care of any uneven surfaces of the ironing table)
- Now place the photo paper on the copper board ( Black printed side down) and hold it in that position.
- Power up the pressing iron and set the temperature knob a little less than "COTTON" setting and let it heat up.
- Once it is heated up.. hold the photo paper firmly down on the copper clad and just press the iron against the copper clad in a corner.. This is very important. Once you press it in any corner.. that part of the black toner gets stuck to the copper.
Now your photo paper won't slide away when ironing it.
- Now place a clean washed,dried handkerchief on the photo paper and start ironing the photo paper as you would normally do it when pressing clothes.
- Keep the pressure equal throughout the process of ironing. Give atleast 3 to 4 rounds of pressing.
- On the final press, just tilt the iron at around 40 degrees as shown in the photo and roll it over the entire PCB surface in the tilted position. This makes sure that that all the artwork is transferred to the copper layer correctly without any flaws.
- Now switch off the iron and remove handkerchief and keep the copper board (stuck with the paper) aside under a running ceiling fan and let it cool for around 10 minutes.
- Keep on checking temperature by touching it .. once it reaches "Just Warm" state.. start peeling out the photo paper from any one corner and slowly roll it away from the copper clad.
- When you are removing the photo paper by rolling it.. if you hear little CLICKS every time you try to separate out.. CONGRATULATIONS !! YOU HAVE NAILED IT !! remove the paper slowly, steadily completely.
- This is a tricky part and you may not succeed in the first GO. But have patience.. you will master this art only through practice
- If this peeling off process doesn't go smooth as explained above.. meaning if you feel that the photo paper is not getting separated out easily … DO NO Forcefully separate it. Just take a enough water(Lukewarm) in a container and add spoonful of Hand Wash soap, mix it and make a soapy solution and dip your copper clad along with the photo paper in it for around 30 minutes.
- Just remember... Patience is a key to success. After 30 minutes take a worn out tooth brush and start scrubbing the paper off the board gently. This will remove the photo paper completely from the cooper clad in around five minutes.
- Once all the paper is removed.. clean you PCB under a running cold tap water for a while
Step 6: Semi - Finished PCB
Now what yo have is a semi-finished PCB in your hand as shown in the attached image.
It is time to cut the copper clad to its size using Hack saw.
Now its the time to ETCH the PCB !!
Step 7: Etching ... Yay !!
LOL !! yes... this is the most time consuming step of all . .
- PREPARE THE ETCHING SOLUTION
- Take a quart water and make it lukewarm and pour it in a flat glass container
Mix around 3 tablespoon full of Ferric Chloride powder in the water and mix it thoroughly
- Take a quart water and make it lukewarm and pour it in a flat glass container
- Now wear surgical gloves and dip the PCB in the FeCl3 solution and keep stirring it
- Take PCB out intermittently to check how much copper is etched..It should take around 30 to 40 minutes to fully etch the PCB. (Size 7cm x 7cm approx.)
- Once all the unwanted copper is dissolved away... take the PCB and wash it under clean running tap water
Step 8: Cleaning the PCB
Now its time to clean the PCB
Clean the PCB by using a scrubber pad and soap solution (Any detergent)
Scrub the PCB with a little more pressure till all the black ink is removed from the copper tracks.
Again wash it under clean running tap water and wipe it with a dry cloth
Step 9: Finishing !!
- Now take a Sand paper and lightly rub it over all the copper tracks till you see a nice shiny copper.
- Wipe it off with a dry cloth
- Switch on the solder gun and by the time it heats up.. take a flux paste and apply a light coat over full PCB using a soft cloth. The PCB is ready for tinning
- Touch the heated tip of the soldering gun with a little solder wire (wire with 80/20 ratio of Tin/Lead) and let it melt over the tip.
- Now place the flat soldering tip on the copper track and rub the iron horizontally on the copper tracks.
You need to do this as quick as you can because if you rest more on any spot on the copper track .. you will see a little solder blob on the tracks and it won't give you a plain finish. Complete this activity in many strokes and melt a little more solder on the tip as required intermittently.
- Once all the copper tacks are covered . . rub the track side PCB with a clean soft cloth to wipe off the extra flux on the surface.
- Now its time to drill holes
Use Hand PCB drill or Electric one.. whichever you have in your toolbox and complete the drilling holes one by one.
- Use drill bits as per the chart below
0,8 mm -- For IC pads
1.2 mm -- For Diodes , Presets and high voltage mylar capacitors
1.0 mm -- For all other components
YOU HAVE JUST CREATED A SUPERB QUALITY P.C.B
Enjoy the feeling of Being on top of the world for the rest of the week lol !!