Prototyping and Making

Prototyping electronic circuits:

  • Using omega kits.
  • Using prototype boards or breadboards.
  • Using Veroboards or Stripboards.
  • Using computer simulations such as Yenka.

Circuit Construction:

  • PCB manufacturing through use of etchant and developer, etc.
    • Etching PCBs require protective gloves without which it is possible that one’s bare hands would come into contact with the etchant or developer, both of which are extremely potent chemicals.
    • Sometimes it is wise to drill small holes into the PCB:
      • You can then thread the wires from components through these holes to ensure that they cannot be pulled off accidentally as seen in the image below.
  • Soldering.

PCB:

  • These are copper clad fibreglass boards and are used because they are:
    • Cheap.
    • Easy to make.
    • Reduces the amount of wires and cable needed to connect the components together:
      • Reduces the chance of wires touching and causing short circuiting.
        • This could cause an electric shock.
  • Making:
    1. Using CAD design schematic then test your circuit.
    2. Create PCB with CAD software using autoroute > Check route and pads are not too close or too fine so that soldering will not be a pain.
    3. Print PCB mask (negative image of the PCB track) using a laser printer onto acetate.
    4. Place the acetate mask over a photosensitive board. Make sure it is the right way up.
    5. Put the assemblage into a UV box, photoetch the light sensitive copper clad board by exposing to UV light.
    6. Peel off the acetate PCB mask (possibly).
    7. Develop in developer bath (sodium hydroxide) and rinse thoroughly with water.
      • This removes all the non-hardened (non-exposed) photosensitive material.
      • Usually takes less than an minute depending on how strong your developer is.
    8. Place the board in the bubble etching tank (ferric chloride) to removes the excess copper and rinse thoroughly with water.
      • The excess copper is the stuff that is left exposed after the non-exposed photosensitive material is removed.
      • The useful copper is hidden and protected by the hardened photosensitive material from the etchant.
      • Usually takes about ten to forty-five minutes.
    9. Remove the remaining hardened photosensitive material using a PCB rubber or iron wool (possibly).
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