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MAKING A PRINTED CIRCUIT BOARD

This method is OK for making single PCBs at home, but if you need to make several then use another method.

Copper laminate (a sheet of insulating material coated with a sheet of copper) is used.
Unwanted copper is etched away to leave component mounting pads and copper tracks to join them.

DESIGNING THE PCB LAYOUT

Bend leads of components and measure the distance between the leads.

Using 0.1" graph paper, draw the component layout showing component mounting pads.
This drawing will show the component (non copper) side of the PCB.

For neatness, make components parallel to edges of the board.

It's best to start near to the centre of the paper so that there is room to expand the layout in all directions, if necessary.

If using integrated circuits, lay these out first and place the other components, and tracks, around them.
The pins of an IC are spaced 0.1". There is 0.3" between the rows of pins.

Draw in the copper tracks which link component pads together.
It may be necessary to provide "jumper" links if it's necessary for a track to cross other tracks.

MARKING OUT THE PCB

Cut out the paper guide and stick to the non copper side of the PCB.
Use a hammer and centre punch to mark the position of the component mounting holes.

Drill out the holes with a 1 mm carbide drill. (be aware that these are very brittle). If you can obtain a 1 mm dental"burr" then this is a much tougher tool.

Also drill mounting holes, usually one at each corner of the PCB.

Use fine emery paper to remove any burrs around the drilled holes.
Polish the copper with a scouring pad or something similar.
Wash and dry.

Avoiding fingerprints, draw component pads and tracks between pads.
Do this using a permanent, fine nibbed, black felt tip pen.
Use the drawing as a guide, remembering that it is a mirror image.
If the graph paper is thin enough, then you can hold it up to the light to see the correct track layout.

ETCHING

Etch using a Ferric Chloride solution.
Note that this corrodes metal and will stain everything it touches.

Either suspend the PCB in the solution, by means of a thread, or float it copper face down, on top of the solution.
If floating, fit the PCB with a paper tape "handle" so that it can be checked every so often.

The process can be speeded up by warming the solution. Stand the container on top of a heating pad.

Once etched, wash and dry.

ASSEMBLY

Check that there are no "bridges" between tracks.Use a modelling knife to remove any.

Read the page on how to solder, if you haven't done any soldering before.

Fit components flat to the board and solder, ensuring values are visible.

Splay out component leads to avoid them falling out during soldering.

Cut component leads close to the board but avoid cutting the solder joint.

Varnish the copper side to avoid tarnishing.