BTEC First Engineering Learning aim A Know about engineering processes used to produce modern engineered products

Surface mount Surface-mount technology (SMT) is a method for producing electronic circuits in which the components are mounted or placed directly onto the surface of printed circuit boards (PCBs). An electronic device so made is called a surface-mount device (SMD). In the industry it has largely replaced the through-hole technology construction method of fitting components with wire leads into holes in the circuit board. Both technologies can be used on the same board for components not suited to surface mounting such as large transformers and heat-sinked power semiconductors.

Printed circuit board Electronic circuits in schools and industry are normally manufactured through the use of PCBs (Printed Circuit Boards). The boards are made from glass reinforced plastic with copper tracks in the place of wires Components are fixed in position by drilling holes through the board, locating the components and then soldering them in place. The copper tracks link the components together forming a circuit.

Process of manufacturing a PCB and SMT Printed circuit board (PCB) manufacture The Surface Mount Technology (SMT) process 1. 1. 2. 2. 3. 3. 4. 4. 5. 5. 6.

Process of manufacturing a PCB and SMT Printed circuit board (PCB) manufacture The Surface Mount Technology (SMT) process Components are soldered to the surface of the board Producing the artwork The finished board is then inspected for imperfections Designing the layout Conveyor belts are used to transport the boards to the reflow soldering oven PCB etching Populating the board and soldering The board is heated to a temperature that melts the solder plate Drilling the board Place components using pick and place robot Apply solder paste to copper pads

4 Scales of production One-off Batch Mass Continuous BTEC First Engineering 4 Scales of production One-off Batch Mass Continuous Teacher notes (PS 4): One-off – designs are made individually (bespoke) for the customer. They are often craftsman made, using hand tools and light equipment. High-cost, high-value products. Batch – a set number are produced, but with flexibility to increase production or individualise designs (e.g. cars produced with different trim levels). Also, a requirement for a repeat amount made at another time, on a regular or irregular basis, time, and quantity. Mass – products made in large numbers, possibly until demand ceases to exist. Little human involvement in production as much is done by automated equipment. Continuous (or flow) – production is indefinite. Commonly associated with liquid products (oil, fizzy drinks etc.) but could be for high-demand items (bottle tops, nails etc.). As with mass production, little to no human involvement in manufacture. © Pearson Education Ltd 2012. Copying permitted for purchasing institution only.

One off Batch Mass Continuous © Pearson Education Ltd 2012. Copying permitted for purchasing institution only.

Scales of production One-off BTEC First Engineering Scales of production One-off Where just one product is made for a customer. Could be a prototype. Batch A set number of identical products. Some flexibility to individualise designs. Mass Products produced in large quantities. Often involves automation. Continuous Automated production can continue for months. Often produces low-cost products. Teacher notes (PS 4): One-off – designs are made individually (bespoke) for the customer. They are often craftsman made, using hand tools and light equipment. High-cost, high-value products. Batch – a set number are produced, but with flexibility to increase production or individualise designs (e.g. cars produced with different trim levels). Also, a requirement for a repeat amount made at another time, on a regular or irregular basis, time, and quantity. Mass – products made in large numbers, possibly until demand ceases to exist. Little human involvement in production as much is done by automated equipment. Continuous (or flow) – production is indefinite. Commonly associated with liquid products (oil, fizzy drinks etc.) but could be for high-demand items (bottle tops, nails etc.). As with mass production, little to no human involvement in manufacture. © Pearson Education Ltd 2012. Copying permitted for purchasing institution only.

Characteristics of different scales of production   ONE OFF BATCH MASS  CONTINUOUS Unit Cost High  Medium Low Tools & equipment General Specialised Specialised and dedicated Initial investments High Production efficiency Medium/high Very high Labour type Skilled Skilled/semi skilled Semi-skilled/unskilled Unskilled Labour costs Low  © Pearson Education Ltd 2012. Copying permitted for purchasing institution only.