Computer and Information Engineering Lab II ECE 3102 & ECE 4102

1. Designing Printed Circuit Board (PCB ) (Tutorial Five) Computer and Information Engineering Lab II ECE 3102 & ECE 4102 رَبِّ زدْنيِ عِلْماً وَ رْزُقْنيِ فَهْما My Lord! Advance me in Knowledge and true understanding .

2. Lecturer: Dr. Nor FarahidahZa’bahDemonstrator:Br. AkhterLab technician:Br. Shahlan Laboratory: Mechatronics Workshop, Room# E2-2-13.12 رَبِّ زدْنيِ عِلْماً وَ رْزُقْنيِ فَهْما My Lord! Advance me in Knowledge and true understanding .

3. Contents • Basic PCB Skills and Tools. • PCB design using Crocodile. • PCB design usingEagle.

4. Basic PCB Skills and Tools Construction of Electronics Projects • Need to know about…… • Types of Circuit Board . • Soldering Guide. • Tools required for electronics. • Starter kit of components. • Making a workbench for electronics.

5. Basic PCB Skills and Tools Types of Circuit Board • Breadboard • Stripboard • Printed Circuit Board Breadboard Stripboard Printed Circuit Board

6. Basic PCB Skills and Tools Types of Circuit Board (Con.) • Breadboard • Temporary use, Normally for testing purpose. • No soldering required. • This is a way of making a temporary circuit. No soldering is required and all the components can be re-used afterwards. It is easy to change connections and replace components. Almost all the Electronics Club projects started life on a breadboard to check that the circuit worked as intended. Breadboard

7. Basic PCB Skills and Tools Types of Circuit Board (Con.) • Stripboard • Permanent, • Soldered . • Stripboardhas parallel strips of copper track on one side. The strips are 0.1" (2.54mm) apart and there are holes every 0.1" (2.54mm). Stripboard requires no special preparation other than cutting to size. It can be cut with a junior hacksaw, or simply snap it along the lines of holes by putting it over the edge of a bench or table and pushing hard. Stripboard

8. Basic PCB Skills and Tools Types of Circuit Board (Con.) • Printed Circuit Board • Permanent, soldered. • Printed circuit boards have copper tracks connecting the holes where the components are placed. They are designed specially for each circuit and make construction very easy. However, producing the PCB requires special equipment so this method is not recommended if you are a beginner unless the PCB is provided for you. Printed Circuit Board

9. Basic PCB Skills and Tools Working With PCB • Single sided layer • Positive board & Negative board A sample of positiveboard the desired circuit will be the one with blackcolor. A sample of negativeboard the desired circuit will be the one with whitecolor.

10. Basic PCB Skills and Tools FLOWCHART Working With PCB (Con.)

11. Basic PCB Skills and Tools After making the PCB ….. Working With PCB (Con.)

12. Basic PCB Skills and Tools Working With PCB (Con.) Step 1 1. Circuit Schematic diagram PCB Layout

13. When the PCB layout (Using software) is finished it is printed on a Transparent Paper and becomes a PCB mask. Basic PCB Skills and Tools Working With PCB (Con.) Step 2

14. Basic PCB Skills and Tools Photo-resist Positive Board Working With PCB (Con.) Step 3 • PHOTO-RESIST BOARD is a piece of glass reinforced plastic. • One of the sides is copper cladwith photosensitive coating. • When the plastic film is peeled back this sensitive coating is revealed. • After processing this will be the PCB.

15. Basic PCB Skills and Tools Placing Photo-resistive board on Mask Working With PCB (Con.) Step 4 • The PCB mask (transparent page) is placed underneath the photo-resist board, touching the sensitive surface. • The plastic film must be removed. • PCB mask and board are then transferred to the UV light Box. • Be careful to ensure that the PCB mask is the right way up, otherwise when the circuit is etched you will discover that the tracks are also the wrong way round.

16. Basic PCB Skills and Tools Using UV Light Box Working With PCB (Con.) Step 5 • The lid is shut and the box switched on. • The photo-resist board, with PCB mask are left underneath the lid for 2 minutes (120 sec.) Note: for negative board, the exposure will be for 25 seconds

17. Basic PCB Skills and Tools Using UV Light Box Working With PCB (Con.) Step 6 & 7 • The photo-resist board is then placed in a tank filled with developer solution. • It is important that the board is only left in the developer for approximately ten seconds. • When the board is taken out of the developer it must be washed in clean water before transferring to the etching tank. • Always use plastic tongs or gloves.

18. Basic PCB Skills and Tools Using UV Light Box Working With PCB (Con.) Step 6 & 7 • The etchant used is Ferric Chloride. • This solution slowly etches away the unwanted copper, leaving the tracks only. • At this stage it is important to keep checking that the PCB is completed • If it is left in the tank too long the copper tracks will also be removed or damaged.

19. Basic PCB Skills and Tools Cleaning & Drilling Working With PCB (Con.) Step 8 & 9 • The last stage is drilling the holes for the components. A small PCB drill is used for this purpose. • Again care is needed as a good PCB can be ruined by careless drilling.

20. Basic PCB Skills and Tools Working With PCB (Con.) Step 10 • Soldering Techniques • Use a soldering iron in good condition. Inspect the tip to make sure that it is not past good operation. If it looks in bad condition it will not help you solder a good joint. The shape of the tip may vary from one soldering iron to the next but generally they should look clean and not burnt. • A PCB eraser is used to remove any film from the tracks. This must be done carefully because the film will prevent good soldering of the components to the PCB. The tracks can be checked using a magnifying glass. If there are gaps in the tracks, sometimes they can be repaired using wire but usually a new PCB has to be etched.

21. Basic PCB Skills and Tools Working With PCB (Con.) Step 10 • Soldering Techniques (Con.) 3. Place the PCB, with its components in position, in the bull clip. This will steady the PCB when you try to use the soldering iron. 4. The heated soldering iron should then be placed in contact with the track and the component and allowed to heat them up. Once they are heated the solder can be applied. The solder should flow through and around the component and the track

22. Basic PCB Skills and Tools Working With PCB (Con.) Step 10 • Soldering Techniques (Con.) 5. Having completed soldering the circuit the extended legs on the components need to be trimmed using wire clippers. The circuit is now ready for testing. Below are some of the warning symbols that appear on etchants and ferric chloride solutions. They are present to warn the user of their potential danger if mishandled. Why should etchants and solutions such as ferric chloride be handle with great care ?

23. Basic PCB Skills and Tools Working With PCB (Con.) Step 11 • Checking & Testing

24. Basic PCB Skills and Tools Working With PCB (Con.) Step 11 • Checking & Testing (Con.)

25. Basic PCB Skills and Tools Working With PCB (Con.) Finally • The Product

26. Basic PCB Skills and Tools Tools Required for Circuit Construction • Soldering iron • A soldering iron is a hand tool used in soldering. It supplies heat to melt the solder so that it can flow into the joint between two work-pieces. • A soldering iron is composed of a heated metal tip and an insulated handle. Heating is often achieved electrically, by passing an electric current through a resistive heating element. • The iron's power rating should be 15 to 25W and it should be fitted with a smallbit of 2 to 3mm diameter.

27. Basic PCB Skills and Tools Tools Required for Circuit Construction (Con.) • Soldering iron stand • You must have a safe place to put the iron when you are not holding it. • The stand should include a sponge which can be dampened for cleaning the tip of the iron.

28. Basic PCB Skills and Tools Tools Required for Circuit Construction (Con.) • De-soldering pump (solder sucker) • A tool for removing solder when de-soldering a joint to correct a mistake or replace a component.

29. Basic PCB Skills and Tools Tools Required for Circuit Construction (Con.) • Reel of solder • The best size for electronics is 22swg (swg = standard wire gauge).

30. Basic PCB Skills and Tools Tools Required for Circuit Construction (Con.) • Cutters • For trimming component leads close to the circuit board.

31. Basic PCB Skills and Tools Tools Required for Circuit Construction (Con.) • Small pliers • Usually called 'snipe nose' pliers, these are for bending component leads etc. If you put a strong rubber band across the handles the pliers make a convenient holder for parts such as switches while you solder the contacts.

32. Basic PCB Skills and Tools Tools Required for Circuit Construction (Con.) • Small flat-blade screwdriver • For scraping away excess flux and dirt between tracks, as well as driving screws.

33. Basic PCB Skills and Tools Tools Required for Circuit Construction (Con.) • Small electric drill • Ideally this should be mounted in a drill stand. • We will need a range of small drill bits, but for most holes a 1mm bit is suitable. Larger holes can be drilled with a hand drill but 1mm bits are too fragile to use reliably in a hand drill.

34. Basic PCB Skills and Tools Soldering Guide: HOW TO SOLDER • A few safety precautions: • Never touch the element or tip of the soldering iron. • They are very hot (about 400°C) and will give you a nasty burn. • Take great care to avoid touching the mains flex with the tip of the iron. • The iron should have a heatproof flex for extra protection. An ordinary plastic flex will melt immediately if touched by a hot iron and there is a serious risk of burns and electric shock. • Always return the soldering iron to its stand when not in use. • Never put it down on your workbench, even for a moment! • Work in a well-ventilated area. • The smoke formed as you melt solder is mostly from the flux and quite irritating. Avoid breathing it by keeping you head to the side of, not above, your work. • Wash your hands after using solder. • Solder contains lead which is a poisonous metal.

35. Basic PCB Skills and Tools Soldering Guide: HOW TO SOLDER (Con.) Always return the soldering iron to its stand when not in use. Use a damp sponge, frequently, to keep the bit clean.

36. Basic PCB Skills and Tools Soldering Guide: HOW TO SOLDER (Con.) Tinning the bit,Heating the joint and applying the solder. Tin the bit for good heat conduction. (This means putting a small blob of solder on the tip of the bit). Hold the iron like a pen. Rest your hands on the workbench to make them steady. Take precautions against the work moving (use a small vice or sticky tape). Heat the biggest part of the joint for 2-3 seconds.

37. Basic PCB Skills and Tools Soldering Guide: HOW TO SOLDER (Con.) PRACTICE MAKES PERFECT !!!

38. Basic PCB Skills and Tools Important Components

39. Basic PCB Skills and Tools Important Components (Con.)

40. Basic PCB Skills and Tools De-soldering Components Tools required:pliers, cutters, soldering iron, and solder sucker (de-soldering tool). Take great care to avoid damage. Components cost a few pence, an assembled printed circuit board may be worth several hundred pounds. Ensure the iron bit is well tinned. Heat up the joint to be de-soldered until the solder runs. Apply the solder sucker and remove the solder. This should only take two or three seconds. Working on a double-sided PCB (where copper tracks are on both sides of the PCB) is more difficult and requires more care. It is often safer to cut the component leads and discard the component, then desolder the leads individually.

41. Circuit Design UsingCrocodile Technology 3D

42. Circuit Design Using Crocodile Technology 3D Crocodile Technology 3D • Crocodile is a compilation of circuit design tools and simulation tools. • This application is also good for beginners who wanted to learn electronics. • The simulation tools help learners / users to experiment circuit connections without being worried about component get burns because of wrongly connected. • You can always replace burnt component with a new one by simply drag and drop.

43. Circuit Design Using Crocodile Technology 3D Creating New File • Click File >> New • Click “Rectangular PCB space” from the Parts Library pane and drag it to the scene space

44. Circuit Design Using Crocodile Technology 3D Working Space Parts tray Click and drag parts to PCB space 3D / PCB space Schematic space Parts tray

45. Circuit Design Using Crocodile Technology 3D Circuit Designing Practice Find and drag all the components below to the PCB space

46. Circuit Design Using Crocodile Technology 3D Drawing the Schematic Draw the schematic below on the schematic space. See the circuit simulation by clicking the switch button on the schematic

47. Circuit Design Using Crocodile Technology 3D Crocodile Technology to Real PCB • Once a circuit has been designed and simulated/testedin Crocodile Technology and any necessary alterations made, the completed circuit is ready for export to ‘real PCB’. • BothCrocodile Technology and Real PCB software must be running at the same time for this to be possible. • The conversion to PCB layout can be achieved through a menu in Crocodile Technology. Real PCB converts the circuit diagram effortlessly to PCB layout and usually with 100% accuracy.

48. Circuit Design Using Crocodile Technology 3D Working with Real PCB • Real PCB can also be used to construct a circuit as a PCB layout, from scratch, by selecting components from a series of menus and drawing the tracks connecting them. It can be used by both beginners and experts to produce accurate PCBs. Quality checks can be carried out automatically and the software will also produce a bill for the components used on any PCB. • The ‘Pour Copper’ menu changes the final PCB by only removing enough copper so that the tracks can be seen. This means that only the necessary copper is removed to ensure the final circuit works. This extends the life of etchant used in the etchant tank. • Two more ways of presenting the PCB. The 'artwork' layout is the most likely to be printed out on a transparency, ready for conversion to PCB. The ‘real life’layout style shows the PCB with its components. This is useful when arranging the components on the PCB, as the position of each can be check against a real life printed.

49. Circuit Design Using Crocodile Technology 3D Working with Real PCB (Con.) When the PCB layout is finished it is printed on a transparency and becomes known as a PCB mask. The PCB mask is transferred to the UV box, which is the next stage in the manufacture of a printed circuit board. Advantages of using circuit and PCB software: Circuits can be simulated on screen without the need to build a circuit on a breadboard with real components. Errors can be corrected and alterations made to the circuit by simply replacing components from menus. No soldering is needed, simply move components with a mouse. Using simulation software is safer than soldering with hot soldering irons and avoids dangerous fumes being produced whilst soldering. Once a PCB has been designed it can be printed onto transparencies repeatedly, all to the same high quality. PCB layout software is more accurate than drawing a circuit by hand.

50. Circuit Design Using Crocodile Technology 3D Working with Real PCB (Con.) • Jumper wires exist when Real PCB finds out that there are no possibilities of copper connection. • But you can always eliminate jumper wires by rearranging the components position. • Try rearranging the components until a PCB artwork with minimum or no jumper wires at all. Jumper wires