Manufacturing Processes

• Photo etching is the method of producing a printed circuit board (PCB).
• The process is a follows:
  1. Print the PCB design onto a clear transparency sheet using a laser printer.
  2. Cut the PCB to size.
  3. Peel the sticker (protective blue layer) from the PCB.
  4. Place the exposed photo-board on top of the laser printed design inside a UV light box.
  5. Allow the PCB to be exposed for the required length of time. Ours takes 4 minutes.
  6. The board now goes into the developer tank which removes the now softened PCB protection layer.
  7. The PCB then goes into the ferric chloride tank to remove the excess copper.
  8. The PCB is then sprayed with photo-resist stripper to remove the final layer of protective film on the PCB.
• This is the best process for making PCBs in schools.
• It is however, a vey slow process and not suitable for mass production.
• All the chemicals need need regular replacement as they become saturated with copper.
• These chemicals will need to be disposed of safely.

• Once the etching process has been completed, the PCB will need to be prepared and populated with components.
• The PCB will need to be drilled using the appropriate size drill bit, usually 1mm, this will be slightly bigger for components with thicker legs. 1.5mm for the download sockets.
• Components are then pushed through the holes and then soldered in place on the opposite side where the copper tracks are.
• You must ensure all the holes are drilled before placing components, as it is usually very difficult to drill holes after the components are placed.

• When you wish to produce a circuit as a prototype to test it before full scale production, one of the methods that can be used is 'breadboarding'.
• A breadboard also known as protoboard is a type of solderless electronic circuit building.You can build a electronic circuit on a breadboard without any soldering! Best of all it is reusable.

• When you need to produce a number of the same product at the same time, a single batch production might be used.
• For this process, jigs (fits over a piece of material to guide accurate cutting or drilling without the need for marking) or templates (a cut-out of a shape that can be drawn around onto the material to mark out quickly and easily) are used.
• A good example of this is vacuum forming. This is a system which uses a mould to produce the same shape repetitively.
• Advantages:
  1. The jigs and templates speed up the process and can be kept for future use.
  2. There is no need for expensive specialist equipment.
  3. increased production efficiency by reducing setup time
  4. improved accuracy and consistency of parts through precise workpiece positioning
  5. decreased labor costs by simplifying operations
  6. reduced scrap rates due to better quality control
  7. the ability to produce identical, interchangeable parts
• Disadvantages:
  1. Very labour intensive using the jigs and templates.
  2. Producting the jigs and templates can be costly
  3. significant setup time
  4. limited flexibility for different workpieces
  5. the need for careful maintenance and storage
  6. potential limitations in adapting to slight variations in material thickness or design

• When you wish to produce a product large scale (in the thousands), you will need to use a mass production method.
• These are the processes you will usually find in factories.
•  Mass-produced metal products include door handles, barbecues and cooking utensils.
• The setup costs for these factories is very high, but as you will be producing thousands of the product, the cost should be offset against this.
• Examples of mass production processes are:
  1. Injection moulding.
  2. Blow moulding.
  3. Stamping.
• Advantage:
  1. Can make products very quickly.
  2. Significantly lower production costs due to economies of scale
  3. Increased efficiency through automation
  4. Standardised product quality
  5. Reduce labour costs
• Disadvantages:
  1. Very expensive to setup
  2. Only cost effective if large numbers are made and sold
  3. Employees who remain part of an assembly line may lack motivation because their tasks are repetitive. The boredom caused by repetitive work can lead to low employee morale and increased levels of turnover.
  4. Resource depletion - Mass production uses large amounts of resources, which can lead to resource depletion.
  5. Pollution - The manufacturing processes and materials used in mass production can cause air and water pollution.

Injection moulding:

Blow moulding:

Stamping:

• This is the next step from mass production but the process runs 24 hours a day.
• This process is used when very high volumes are needed and the factory can not be shut down over night.
• When the process is very long and stopping and starting it can cause serious delay then this process is used.
• A good example of this is the car industry. If any stage in the production line is stopped delays and backups are created in other parts of the line.
• Advantage:
  1. Makes larger numbers of products very cheaply and quickly.
  2. Increased production rate: Continuous production can run 24/7, allowing factories to produce large quantities of goods. 
  3.  
     Cost efficiency: Continuous production can reduce labour costs and streamline workflows. 
  4.  
     Higher quality control: Continuous production can reduce human error and maintain product standards. 
      
• Disadvantages:
  1. Machinery is very expensive.
  2. Only worthwhile if very large numbers of the product are made and sold.
  3. Limited flexibility to change products
  4. Potential for overstocking
  5. High resource intensity due to always running machinery
  6. Increased risk of production disruptions if a single machine fails
  7. Lack of adaptability to changing market demands